Analysis of orbital perturbations acting on objects in orbits near geosynchronous earth orbit
NASA Technical Reports Server (NTRS)
Friesen, Larry J.; Jackson, Albert A., IV; Zook, Herbert A.; Kessler, Donald J.
1992-01-01
The paper presents a numerical investigation of orbital evolution for objects started in GEO or in orbits near GEO in order to study potential orbital debris problems in this region. Perturbations simulated include nonspherical terms in the earth's geopotential field, lunar and solar gravity, and solar radiation pressure. Objects simulated include large satellites, for which solar radiation pressure is insignificant, and small particles, for which solar radiation pressure is an important force. Results for large satellites are largely in agreement with previous GEO studies that used classical perturbation techniques. The orbit plane of GEO satellites placed in a stable plane orbit inclined approximately 7.3 deg to the equator experience very little precession, remaining always within 1.2 percent of their initial orientation. Solar radiation pressure generates two major effects on small particles: an orbital eccentricity oscillation anticipated from previous research, and an oscillation in orbital inclination.
NASA Astrophysics Data System (ADS)
Hu, Yun-peng; Li, Ke-bo; Xu, Wei; Chen, Lei; Huang, Jian-yu
2016-08-01
Space-based visible (SBV) program has been proved to be with a large advantage to observe geosynchronous earth orbit (GEO) objects. With the development of SBV observation started from 1996, many strategies have come out for the purpose of observing GEO objects more efficiently. However it is a big challenge to visit all the GEO objects in a relatively short time because of the distribution characteristics of GEO belt and limited field of view (FOV) of sensor. And it's also difficult to keep a high coverage of the GEO belt every day in a whole year. In this paper, a space-based observation strategy for GEO objects is designed based on the characteristics of the GEO belt. The mathematical formula of GEO belt is deduced and the evolvement of GEO objects is illustrated. There are basically two kinds of orientation strategies for most observation satellites, i.e., earth-oriented and inertia-directional. Influences of both strategies to their own observation regions are analyzed and compared with each other. A passive optical instrument with daily attitude-adjusting strategies is proposed to increase the daily coverage rate of GEO objects in a whole year. Furthermore, in order to observe more GEO objects in a relatively short time, the strategy of a satellite with multi-sensors is proposed. The installation parameters between different sensors are optimized, more than 98% of GEO satellites can be observed every day and almost all the GEO satellites can be observed every two days with 3 sensors (FOV: 6° × 6°) on the satellite under the strategy of daily pointing adjustment in a whole year.
Bi-static Optical Observations of GEO Objects
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Barker, Edwin S.; Cowardin, Heather; Lederer, Susan M.; Buckalew, Brent
2014-01-01
A bi-static study of objects at Geosynchronous Earth Orbit (GEO) was conducted using two ground-based wide-field optical telescopes. The University of Michigan's 0.6-m MODEST (Michigan Orbital Debris Survey Telescope) located at the Cerro Tololo Inter- American Observatory in Chile was employed in a series of coordinated observations with the U.S. Naval Observatory's (USNO) 1.3-m telescope at the USNO Flagstaff Station near Flagstaff, Arizona, USA. The goals of this project are twofold: (1) Obtain optical distances to known and unknown objects at GEO from the difference in the observed topocentric position of objects measured with respect to a reference star frame. The distance can be derived directly from these measurements, and is independent of any orbital solution. The wide geographical separation of these two telescopes means that the parallax difference is larger than ten degrees, and (2) Compare optical photometry in similar filters of GEO objects taken during the same time period from the two sites. The object's illuminated surfaces presented different angles of reflected sunlight to the two telescopes.During a four hour period on the night.of 22 February 2014 (UT), coordinated observations were obtained for eight different GEO positions. Each coordinated observation sequence was started on the hour or half-hour, and was selected to ensure the same cataloged GEO object was available in the field of view of both telescopes during the thirty minute observing sequence. GEO objects were chosen to be both controlled and uncontrolled at a range of orbital inclinations, and the objects were not tracked. Instead both telescopes were operated with all drives off in GEO survey mode to discover un-cataloged objects at GEO. The initial results from this proof-of-concept observing run will be presented, with the intent of laying the foundation for future large-scale bi-static observing campaigns of the GEO regime.
Drifting Recovery Base Concept for GEO Derelict Object Capture
NASA Technical Reports Server (NTRS)
Bacon, John B.
2009-01-01
Over 250 objects hover within 6 m/sec of perfect geostationary orbit. Over half of these objects lie within 0.1 m/sec of the GEO velocity. Such items have 62% of the total velocity required to achieve Earth gravitational escape. A conceptual architecture is proposed to clean this orbit area of derelict objects while providing a demonstration mission for many facets of future asteroid mining operations. These near-GEO objects average nearly 2000kg each, consisting of (typically functioning) power systems, batteries, and large quantities of components and raw aerospace-grade refined materials. Such a demonstration collection system could capture, collect and remove all GEO derelict objects in an international effort to create a depot of components and of aerospace-grade raw materials--with a total mass greater than that of the International Space Station--as a space scrap depot ready for transfer to lunar or Mars orbit, using only two heavy-lift launches and 2-3 years of on-orbit operations.
Population evolution in the GEO vicinity
NASA Astrophysics Data System (ADS)
Wegener, P.; Bendisch, J.; Krag, H.; Stabroth, S.
The geostationary orbit is now in use for nearly 40 years. Due to the absence of major energy dissipating mechanisms, the object population in the GEO environment steadily grew during this time. In mid 2001, a total of 762 known objects permanently resided within the GEO region (GEO +/-1000 km). Additionally, two explosion events are confirmed within the geostationary ring, which further enlarge the already existing population consisting of payloads and upper stages. Recent observation results obtained by the ESA Space Debris Telescope (SDT) at Tenerife show strong indications for even more fragment clouds. Since the geostationary ring can be seen as a unique resource, which is not protected by any significant selfcleaning effect, a monitoring of the object environment in the vicinity of this orbit is mandatory. In a first step, this paper characterizes the history and current state of the GEO environment. The evolution of fresh object clouds within and out of the ring is analysed to get a better understanding of the short- and mid-term impact of explosion events as well as Solid Rocket Motor (SRM) firings on the overall population. Next to explosion prevention, the transfer of satellites to a graveyard orbit about 300 km above the geostationary altitude is agreed to be the most effective mean to preserve GEO. Although this procedure is internationally recommended, only one third of the retiring spacecraft is in fact brought to a sufficiently high orbit. Another 30% performs a re-orbiting, but is ending up in an orbit in the direct vicinity of the GEO ring or even touching or crossing it. The reason for this low performance often can be found in insufficient fuel gauging or urgent need for several more months of operation. In the future, one possibility to mitigate the population growth by remo v - i n g those spacecraft could be a dedicated vehicle transferring several large objects to the graveyard area before retiring there on its own. The number and distribution of possible candidates for such a removal is outlined. Assuming a future traffic model and different scenarios for re-orbiting and removal, the future evolution of the large object population in and near GEO can be estimated.
Results in orbital evolution of objects in the geosynchronous region
NASA Technical Reports Server (NTRS)
Friesen, Larry Jay; Jackson, Albert A., IV; Zook, Herbert A.; Kessler, Donald J.
1990-01-01
The orbital evolution of objects at or near geosynchronous orbit (GEO) has been simulated to investigate possible hazards to working geosynchronous satellites. Orbits of both large satellites and small particles have been simulated, subject to perturbations by nonspherical geopotential terms, lunar and solar gravity, and solar radiation pressure. Large satellites in initially circular orbits show an expected cycle of inclination change driven by lunar and solar gravity, but very little altitude change. They thus have little chance of colliding with objects at other altitudes. However, if such a satellite is disrupted, debris can reach thousands of kilometers above or below the initial satellite altitude. Small particles in GEO experience two cycles driven by solar radiation: an expected eccentricity cycle and an inclination cycle not expected. Particles generated by GEO insertion stage solid rocket motors typically hit the earth or escape promptly; a small fraction appear to remain in persistent orbits.
GEO Collisional Risk Assessment Based on Analysis of NASA-WISE Data and Modeling
NASA Astrophysics Data System (ADS)
Howard, S.; Murray-Krezan, J.; Dao, P.; Surka, D.
From December 2009 thru 2011 the NASA Wide-Field Infrared Survey Explorer (WISE) gathered radiometrically exquisite measurements of debris in near Earth orbits, substantially augmenting the current catalog of known debris. The WISE GEO-belt debris population adds approximately 2,000 previously uncataloged objects. This paper describes characterization of the WISE GEO-belt orbital debris population in terms of location, epoch, and size. The WISE GEO-belt debris population characteristics are compared with the publically available U.S. catalog and previous descriptions of the GEO-belt debris population. We found that our results differ from previously published debris distributions, suggesting the need for updates to collision probability models and a better measurement-based understanding of the debris population. Previous studies of collisional rate in GEO invoke the presence of a large number of debris in the regime of sizes too small to track, i.e. not in the catalog, but large enough to cause significant damage and fragmentation in a collision. A common approach is to estimate that population of small debris by assuming that it is dominated by fragments and therefore should follow trends observed in fragmentation events or laboratory fragmentation tests. In other words, the population of debris can be extrapolated from trackable sizes to small sizes using an empirically determined trend of population as a function of size. We use new information suggested by the analysis of WISE IR measurements to propose an updated relationship. Our trend is an improvement because we expect that an IR emissive signature is a more reliable indicator of physical size. Based on the revised relationship, we re-estimate the total collisional rate in the GEO belt with the inclusion of projected uncatalogued debris and applying a conjunction assessment technique. Through modeling, we evaluate the hot spots near the geopotential wells and the effects of fragmentation in the GEO graveyard to the collision with GEO objects.
NASA Technical Reports Server (NTRS)
Shie, C.-L.; Tao, W.-K.; Hou, A.; Lin, X.
2006-01-01
The GCE (Goddard Cumulus Ensemble) model, which has been developed and improved at NASA Goddard Space Flight Center over the past two decades, is considered as one of the finer and state-of-the-art CRMs (Cloud Resolving Models) in the research community. As the chosen CRM for a NASA Interdisciplinary Science (IDS) Project, GCE has recently been successfully upgraded into an MPI (Message Passing Interface) version with which great improvement has been achieved in computational efficiency, scalability, and portability. By basically using the large-scale temperature and moisture advective forcing, as well as the temperature, water vapor and wind fields obtained from TRMM (Tropical Rainfall Measuring Mission) field experiments such as SCSMEX (South China Sea Monsoon Experiment) and KWAJEX (Kwajalein Experiment), our recent 2-D and 3-D GCE simulations were able to capture detailed convective systems typical of the targeted (simulated) regions. The GEOS-3 [Goddard EOS (Earth Observing System) Version-3] reanalysis data have also been proposed and successfully implemented for usage in the proposed/performed GCE long-term simulations (i.e., aiming at producing massive simulated cloud data -- Cloud Library) in compensating the scarcity of real field experimental data in both time and space (location). Preliminary 2-D or 3-D pilot results using GEOS-3 data have generally showed good qualitative agreement (yet some quantitative difference) with the respective numerical results using the SCSMEX observations. The first objective of this paper is to ensure the GEOS-3 data quality by comparing the model results obtained from several pairs of simulations using the real observations and GEOS-3 reanalysis data. The different large-scale advective forcing obtained from these two kinds of resources (i.e., sounding observations and GEOS-3 reanalysis) has been considered as a major critical factor in producing various model results. The second objective of this paper is therefore to investigate and present such an impact of large-scale forcing on various modeled quantities (such as hydrometeors, rainfall, and etc.). A third objective is to validate the overall GCE 3-D model performance by comparing the numerical results with sounding observations, as well as available satellite retrievals.
Optical Studies of Orbital Debris at GEO Using Two Telescopes
NASA Technical Reports Server (NTRS)
Seitzer, P.; Abercromby, K. J.; Rodriquez,H. M.; Barker, E.
2008-01-01
Beginning in March, 2007, optical observations of debris at geosynchronous orbit (GEO) were commenced using two telescopes simultaneously at the Cerro Tololo Inter-American Observatory (CTIO) in Chile. The University of Michigan's 0.6/0.9-m Schmidt telescope MODEST (for Michigan Orbital DEbris Survey Telescope) was used in survey mode to find objects that potentially could be at GEO. Because GEO objects only appear in this telescope's field of view for an average of 5 minutes, a full six-parameter orbit can not be determined. Interrupting the survey for follow-up observations leads to incompleteness in the survey results. Instead, as objects are detected on MODEST, initial predictions assuming a circular orbit are done for where the object will be for the next hour, and the objects are reacquired as quickly as possible on the CTIO 0.9-m telescope. This second telescope then follows-up during the first night and, if possible, over several more nights to obtain the maximum time arc possible, and the best six parameter orbit. Our goal is to obtain an initial orbit for all detected objects fainter than R = 15th in order to estimate the orbital distribution of objects selected on the basis of two observational criteria: magnitude and angular rate. Objects fainter than 15th are largely uncataloged and have a completely different angular rate distribution than brighter objects. Combining the information obtained for both faint and bright objects yields a more complete picture of the debris environment rather than just concentrating on the faint debris. One objective is to estimate what fraction of objects selected on the basis of angular rate are not at GEO. A second objective is to obtain magnitudes and colors in standard astronomical filters (BVRI) for comparison with reflectance spectra of likely spacecraft materials. This paper reports on results from two 14 night runs with both telescopes: in March and November 2007: (1) A significant fraction of objects fainter than R = 15th have eccentric orbits (e > 0.1) (2) Virtually all objects selected on the basis of angular rate are in the GEO and GTO regimes. (3) Calibrated magnitudes and colors in BVRI were obtained for many objects fainter than R = 15th magnitude. This work is supported by NASA's Orbital Debris Program Office, Johnson Space Center, Houston, Texas, USA.
Visible Light Spectroscopy of GEO Debris
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Lederer, Susan M.; Cowardin, Heather; Barker, Edwin S.; Abercromby, Kira J.
2012-01-01
Our goal is to understand the physical characteristics of debris at geosynchronous orbit (GEO). Our approach is to compare the observed reflectance as a function of wavelength with laboratory measurements of typical spacecraft surfaces to understand what the materials are likely to be. Because debris could be irregular in shape and tumbling at an unknown rate, rapid simultaneous measurements over a range of wavelengths are required. Acquiring spectra of optically faint objects with short exposure times to minimize these effects requires a large telescope. We describe optical spectroscopy obtained during 12-14 March 2012 with the IMACS imaging spectrograph on the 6.5-m 'Walter Baade' Magellan telescope at Las Campanas Observatory in Chile. When used in f/2 imaging mode for acquisition, this instrument has a field of view of 30 arc-minutes in diameter. After acquisition and centering of a GEO object, a 2.5 arc-second wide slit and a grism are moved into the beam for spectroscopy. We used a 200 l/mm grism blazed at 660 nm for wavelength coverage in the 500-900 nm region. Typical exposure times for spectra were 15-30 seconds. Spectra were obtained for five objects in the GEO regime listed as debris in the US Space Command public catalog, and one high area to mass ratio GEO object. In addition spectra were obtained of three cataloged IDCSP (Initial Defense Communications Satellite Program) satellites with known initial properties just below the GEO regime. All spectra were calibrated using white dwarf flux standards and solar analog stars. We will describe our experiences using Magellan, a telescope never used previously for orbital debris spectroscopy, and our initial results.
Activities of JAXA's Innovative Technology Center on Space Debris Observation
NASA Astrophysics Data System (ADS)
Yanagisawa, T.; Kurosaki, H.; Nakajima, A.
The innovative technology research center of JAXA is developing observational technologies for GEO objects in order to cope with the space debris problem. The center had constructed the optical observational facility for space debris at Mt. Nyukasa, Nagano in 2006. As observational equipments such as CCD cameras and telescopes were set up, the normal observation started. In this paper, the detail of the facilities and its activities are introduced. The observational facility contains two telescopes and two CCD cameras. The apertures of the telescopes are 35cm and 25 cm, respectively. One CCD camera in which 2K2K chip is installed can observe a sky region of 1.3 times 1.3-degree using the 35cm telescope. The other CCD camera that contains two 4K2K chips has an ability to observe 2.6 times 2.6-degree's region with the 25cm telescope. One of our main objectives is to detect faint GEO objects that are not catalogued. Generally, the detection limit of GEO object is determined by the aperture of the telescope. However, by improving image processing techniques, the limit may become low. We are developing some image processing methods that use many CCD frames to detect faint objects. We are trying to use FPGA (Field Programmable Gate Array) system to reduce analyzing time. By applying these methods to the data taken by a large telescope, the detection limit will be significantly lowered. The orbital determination of detected GEO debris is one of the important things to do. Especially, the narrow field view of an optical telescope hinders us from re-detection of the GEO debris for the orbital determination. Long observation time is required for one GEO object for the orbital determination that is inefficient. An effective observation strategy should be considered. We are testing one observation method invented by Umehara that observes one inertia position in the space. By observing one inertia position for two nights, a GEO object that passed through the position in the first night must pass through the position in the second night. The rough orbit is determined from two nights' data. The test observation showed that this method was able to detect many GEO objects and determined their orbits by three nights' observations. We also joined the campaign observations of IADC(Inter-Agency Space Debris Coordination Committee). By analyzing the observed data with the method that we developed, 88 catalogued and 38 un-catalogued objects were detected. The magnitude of the faintest object detected in this campaign observation was 18.5. The object is un-detectable by human inspection.
VoPham, Trang; Hart, Jaime E; Laden, Francine; Chiang, Yao-Yi
2018-04-17
Geospatial artificial intelligence (geoAI) is an emerging scientific discipline that combines innovations in spatial science, artificial intelligence methods in machine learning (e.g., deep learning), data mining, and high-performance computing to extract knowledge from spatial big data. In environmental epidemiology, exposure modeling is a commonly used approach to conduct exposure assessment to determine the distribution of exposures in study populations. geoAI technologies provide important advantages for exposure modeling in environmental epidemiology, including the ability to incorporate large amounts of big spatial and temporal data in a variety of formats; computational efficiency; flexibility in algorithms and workflows to accommodate relevant characteristics of spatial (environmental) processes including spatial nonstationarity; and scalability to model other environmental exposures across different geographic areas. The objectives of this commentary are to provide an overview of key concepts surrounding the evolving and interdisciplinary field of geoAI including spatial data science, machine learning, deep learning, and data mining; recent geoAI applications in research; and potential future directions for geoAI in environmental epidemiology.
NASA Technical Reports Server (NTRS)
Mulrooney, M.; Hickson, P.; Stansbery, Eugene G.
2010-01-01
MCAT (Meter-Class Autonomous Telescope) is a 1.3m f/4 Ritchey-Chr tien on a double horseshoe equatorial mount that will be deployed in early 2011 to the western pacific island of Legan in the Kwajalein Atoll to perform orbital debris observations. MCAT will be capable of tracking earth orbital objects at all inclinations and at altitudes from 200 km to geosynchronous. MCAT s primary objective is the detection of new orbital debris in both low-inclination low-earth orbits (LEO) and at geosynchronous earth orbit (GEO). MCAT was thus designed with a fast focal ratio and a large unvignetted image circle able to accommodate a detector sized to yield a large field of view. The selected primary detector is a close-cycle cooled 4Kx4K 15um pixel CCD camera that yields a 0.9 degree diagonal field. For orbital debris detection in widely spaced angular rate regimes, the camera must offer low read-noise performance over a wide range of framing rates. MCAT s 4-port camera operates from 100 kHz to 1.5 MHz per port at 2 e- and 10 e- read noise respectively. This enables low-noise multi-second exposures for GEO observations as well as rapid (several frames per second) exposures for LEO. GEO observations will be performed using a counter-sidereal time delay integration (TDI) technique which NASA has used successfully in the past. For MCAT the GEO survey, detection, and follow-up prediction algorithms will be automated. These algorithms will be detailed herein. For LEO observations two methods will be employed. The first, Orbit Survey Mode (OSM), will scan specific orbital inclination and altitude regimes, detect new orbital debris objects against trailed background stars, and adjust the telescope track to follow the detected object. The second, Stare and Chase Mode (SCM), will perform a stare, then detect and track objects that enter the field of view which satisfy specific rate and brightness criteria. As with GEO, the LEO operational modes will be fully automated and will be described herein. The automation of photometric and astrometric processing (thus streamlining data collection for environmental modeling) will also be discussed.
Merging analytic and empirical GEO debris synchronization dynamics
NASA Astrophysics Data System (ADS)
Anderson, Paul V.; McKnight, Darren S.; Di Pentino, Frank; Schaub, Hanspeter
2016-09-01
The motion of abandoned satellites near the geostationary (GEO) region has been extensively studied, modeled, and compared to the motion of station-kept, operational satellites, providing insights into the evolution of uncontrolled orbits at GEO. Analytic developments produced a family of curves represented in the ascending node versus inclination space describing the long-term precession of the orbit plane at GEO, and forecasted the clustering of objects at the geopotential wells. However, recent investigations were undertaken to characterize apparent anomalistic behavior of GEO objects and classification of objects into related families. This paper provides a unifying summary of early bottom-up analytical theory with more recent top-down operational observations, highlighting the common linkage between these dimensions of GEO object behavior. This paper also identifies the relevance of these patterns of life tendencies for future operations at and near GEO, and discusses the long-term implications of these patterns of life for space situational awareness activities in this regime.
Deep Space Wide Area Search Strategies
NASA Astrophysics Data System (ADS)
Capps, M.; McCafferty, J.
There is an urgent need to expand the space situational awareness (SSA) mission beyond catalog maintenance to providing near real-time indications and warnings of emerging events. While building and maintaining a catalog of space objects is essential to SSA, this does not address the threat of uncatalogued and uncorrelated deep space objects. The Air Force therefore has an interest in transformative technologies to scan the geostationary (GEO) belt for uncorrelated space objects. Traditional ground based electro-optical sensors are challenged in simultaneously detecting dim objects while covering large areas of the sky using current CCD technology. Time delayed integration (TDI) scanning has the potential to enable significantly larger coverage rates while maintaining sensitivity for detecting near-GEO objects. This paper investigates strategies of employing TDI sensing technology from a ground based electro-optical telescope, toward providing tactical indications and warnings of deep space threats. We present results of a notional wide area search TDI sensor that scans the GEO belt from three locations: Maui, New Mexico, and Diego Garcia. Deep space objects in the NASA 2030 debris catalog are propagated over multiple nights as an indicative data set to emulate notional uncatalogued near-GEO orbits which may be encountered by the TDI sensor. Multiple scan patterns are designed and simulated, to compare and contrast performance based on 1) efficiency in coverage, 2) number of objects detected, and 3) rate at which detections occur, to enable follow-up observations by other space surveillance network (SSN) sensors. A step-stare approach is also modeled using a dedicated, co-located sensor notionally similar to the Ground-Based Electro-Optical Deep Space Surveillance (GEODSS) tower. Equivalent sensitivities are assumed. This analysis quantifies the relative benefit of TDI scanning for the wide area search mission.
NASA Astrophysics Data System (ADS)
Koblick, D. C.; Shankar, P.; Xu, S.
Previously, there have been many commercial proposals and extensive academic studies regarding ground and space based sensors to assist a space surveillance network in obtaining metric observations of satellites and debris near Geosynchronous Earth Orbit (GEO). Most use physics based models for geometric constraints, lighting, and tasker/scheduler operations of sensor architectures. Under similar physics modeling assumptions, the space object catalog is often different due to proprietary standards and datasets. Lack of catalog commonality between studies creates barriers and difficulty comparing performance benefits of sensor trades. To solve this problem, we have constructed a future GEO space catalog from publicly available datasets and literature. The annual number of new payloads and rocket bodies is drawn from a Poisson distribution while the growth of the current GEO catalog is bootstrapped from the historical payload, upper stage, and debris data. We adopt a spherically symmetric explosion model and couple it with the NASA standard breakup model to simulate explosions of payloads and rocket bodies as they are the primary drivers of the debris population growth. The cumulative number of fragments follow a power-law distribution. Result from 1,000 random catalog growth simulations indicates that the GEO space object population in the year 2050 will include over 3,600 objects, nearly half of which are debris greater than 10 cm spherical diameter. The number of rocket bodies and dead payloads is projected to nearly double over the next 33 years. For comparison, the current Air Force Space Command catalog snapshot contains fewer than 50 pieces of debris and coarse Radar Cross Section (RCS) estimates which include: small, medium, and large. The current catalog may be sufficient for conjunction studies, but not for analyzing future sensor system performance. The 2050 GEO projected catalog will be available online for commercial/academic research and development.
Photometric Studies of Orbital Debris at GEO
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Cowardin, Heather M.; Barker, Ed; Abercromby, Kira J.; Foreman, Gary; Hortsman, Matt
2009-01-01
Orbital debris represents a significant and increasing risk to operational spacecraft. Here we report on photometric observations made in standard BVRI filters at the Cerro Tololo Inter-American Observatory (CTIO) in an effort to determine the physical characteristics of optically faint debris at geosynchronous Earth orbit (GEO). Our sample is taken from GEO objects discovered in a survey with the University of Michigan s 0.6-m Curtis-Schmidt telescope (known as MODEST, for Michigan Orbital DEbris Survey Telescope), and then followed up in real-time with the CTIO/SMARTS 0.9-m for orbits and photometry. For a sample of 50 objects, calibrated sequences in RB- V-I-R filters have been obtained with the CTIO/SMARTS 0.9-m. For objects that do not show large brightness variations, the colors are largely redder than solar in both B-R and R-I. The width of the color distribution may be intrinsic to the nature of the surfaces, but also could imply that we are seeing irregularly shaped objects and measuring the colors at different times with just one telescope. For irregularly shaped objects tumbling at unknown orientations and rates, such sequential filter measurements using one telescope are subject to large errors for interpretation. If all observations in all filters in a particular sequence are of the same surface at the same solar and viewing angles, then the colors are meaningful. Where this is not the case, interpretation of the observed colors is impossible. For a smaller sample of objects we have observed with synchronized CCD cameras on the two telescopes. The CTIO/SMARTS 0.9-m observes in B, and the Schmidt in R. The CCD cameras are electronically linked together so that the start time and duration of observations are both the same to better than 50 milliseconds. Now the observed B-R color is a true measure of the scattered illuminated area of the debris piece for that observation.
Cohort profile: the Geoscience and Health Cohort Consortium (GECCO) in the Netherlands
Timmermans, Erik J; Lakerveld, Jeroen; Beulens, Joline W J; Boomsma, Dorret I; Kramer, Sophia E; Oosterman, Mirjam; Willemsen, Gonneke; Stam, Mariska; Nijpels, Giel; Schuengel, Carlo; Smit, Jan H; Brunekreef, Bert; Dekkers, Jasper E C; Deeg, Dorly J H; Penninx, Brenda W J H; Huisman, Martijn
2018-01-01
Purpose In the Netherlands, a great variety of objectively measured geo-data is available, but these data are scattered and measured at varying spatial and temporal scales. The centralisation of these geo-data and the linkage of these data to individual-level data from longitudinal cohort studies enable large-scale epidemiological research on the impact of the environment on public health in the Netherlands. In the Geoscience and Health Cohort Consortium (GECCO), six large-scale and ongoing cohort studies have been enriched with a variety of existing geo-data. Here, we introduce GECCO by describing: (1) the phenotypes of the involved cohort studies, (2) the collected geo-data and their sources, (3) the methodology that was used to link the collected geo-data to individual cohort studies, (4) the similarity of commonly used geo-data between our consortium and the nationwide situation in the Netherlands and (5) the distribution of geo-data within our consortium. Participants GECCO includes participants from six prospective cohort studies (eg, 44 657 respondents (18–100 years) in 2006) and it covers all municipalities in the Netherlands. Using postal code information of the participants, geo-data on the address-level, postal code-level as well as neighbourhood-level could be linked to individual-level cohort data. Findings to date The geo-data could be successfully linked to almost all respondents of all cohort studies, with successful data-linkage rates ranging from 97.1% to 100.0% between cohort studies. The results show variability in geo-data within and across cohorts. GECCO increases power of analyses, provides opportunities for cross-checking and replication, ensures sufficient geographical variation in environmental determinants and allows for nuanced analyses on specific subgroups. Future plans GECCO offers unique opportunities for (longitudinal) studies on the complex relationships between the environment and health outcomes. For example, GECCO will be used for further research on environmental determinants of physical/psychosocial functioning and lifestyle behaviours. PMID:29886447
Optical Observations of Space Debris
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Abercromby, Kira; Rodriquez, Heather; Barker, Edwin S.; Kelecy, Thomas
2008-01-01
This viewgraph presentation reviews the use of optical telescopes to observe space debris. .It will present a brief review of how the survey is conducted, and what some of the significant results encompass. The goal is to characterize the population of debris objects at GEO, with emphasis on the faint object population. Because the survey observations extend over a very short arc (5 minutes), a full six parameter orbit can not be determined. Recently we have begun to use a second telescope, the 0.9-m at CTIO, as a chase telescope to do follow-up observations of potential GEO debris candidates found by MODEST. With a long enough sequence of observations, a full six-parameter orbit including eccentricity can be determined. The project has used STK since inception for planning observing sessions based on the distribution of bright cataloged objects and the anti-solar point (to avoid eclipse). Recently, AGI's Orbit Determination Tool Kit (ODTK) has been used to determine orbits, including the effects of solar radiation pressure. Since an unknown fraction of the faint debris at GEO has a high area-to-mass ratio (A/M), the orbits are perturbed significantly by solar radiation. The ODTK analysis results indicate that temporal variations in the solar perturbations, possibly due to debris orientation dynamics, can be estimated in the OD process. Additionally, the best results appear to be achieved when solar forces orthogonal to the object-Sun line are considered. Determining the A/M of individual objects and the distribution of A/M values of a large sample of debris is important to understanding the total population of debris at GEO
Using GEO Optical Observations to Infer Orbit Populations
NASA Technical Reports Server (NTRS)
Matney, Mark; Africano, John
2002-01-01
NASA's Orbital Debris measurements program has a goal to characterize the small debris environment in the geosynchronous Earth-orbit (GEO) region using optical telescopes ("small" refers to objects too small to catalog and track with current systems). Traditionally, observations of GEO and near-GEO objects involve following the object with the telescope long enough to obtain an orbit. When observing very dim objects with small field-of-view telescopes, though, the observations are generally too short to obtain accurate orbital elements. However, it is possible to use such observations to statistically characterize the small object environment. A telescope pointed at a particular spot could potentially see objects in a number of different orbits. Inevitably, when looking at one region for certain types of orbits, there are objects in other types of orbits that cannot be seen. Observation campaigns are designed with these limitations in mind and are set up to span a number of regions of the sky, making it possible to sample all potential orbits under consideration. Each orbit is not seen with the same probability, however, so there are observation biases intrinsic to any observation campaign. Fortunately, it is possible to remove such biases and reconstruct a meaningful estimate of the statistical orbit populations of small objects in GEO. This information, in turn, can be used to investigate the nature of debris sources and to characterize the risk to GEO spacecraft. This paper describes these statistical tools and presents estimates of small object GEO populations.
The Classical Laplace Plane and Its use as a Stable Disposal Orbit for GEO
NASA Astrophysics Data System (ADS)
Rosengren, A.; Scheeres, D.; McMahon, J.
2013-09-01
The geosynchronous Earth orbit (GEO) is the most susceptible region to space debris because there is no natural cleansing mechanism, such as atmospheric drag. Placing satellites in super-synchronous disposal orbits at the ends of their operational lifetimes has been recommended and practiced as one possible means of protecting this environment. The discovery of the high area-to-mass ratio (HAMR) debris population in near geosynchronous orbit (ca. 2004) raises concern for the long-term sustainability of this unique resource. It is currently believed that HAMR objects are sheets of multilayer insulation detaching from satellites in GEO disposal orbits due to surface degradation and material deterioration. The low energy release of HAMR objects from aging satellites abandoned in disposal orbits is not directly addressed in the national policies that established the graveyard. The current disposal regions cannot account for the large solar radiation pressure (SRP) perturbations of HAMR objects, implying that these storage orbits are not well suited as a graveyard. The orbital dynamics of uncontrolled GEO satellites is governed by the oblateness of the Earth and luni-solar gravitational interactions. By itself, Earth's oblateness causes the pole of the orbital plane to precess around Earth's rotation pole. Lunisolar perturbations will have a similar effect, but the precession will now take place about the orbit poles of the Moon and the Sun, respectively. The classical Laplace plane is the mean reference plane about whose axis the satellite's orbit precesses. On the Laplace place, the secular orbital evolution driven by the combined effects of these perturbations is zero, so that the orbits are frozen. The Laplace plane at GEO lies between the plane of the Earth's equator and that of the ecliptic, passing through their intersection, and has an inclination of about 7.5 degrees relative to Earth's equator. The uncontrolled GEO satellites precess at a constant inclination about the pole of this plane with a period of nearly 53 years. The significance of the Laplace plane for use as a GEO disposal orbit is that the orbits of satellites placed in this stable equilibrium will be fixed on average, and that any orbit at small inclination to it regresses around this plane at nearly constant inclination and rate. This stable graveyard can be specified for a range of semi-major axes above GEO, and satellites placed in this region will have significantly reduced relative encounter velocities, compared to the current graveyard. Thus, if collisions were to occur between satellites in the stable graveyard, they would occur at very low velocities, thereby damping out the relative motion of these objects. We explore the use of the classical Laplace plane as a long-term GEO disposal orbit. We show that HAMR objects released from satellites located in this stable equilibrium will be trapped in inclination and node phase space, and will not likely cross the GEO protected region. This is followed by a discussion of the robustness of these solutions to more realistic SRP models and an investigation of the economic viability of our proposed GEO graveyard.
Geostationary Coastal and Air Pollution Events (GeoCAPE) Filter Radiometer (FR)
NASA Technical Reports Server (NTRS)
Kotecki, Carl; Chu, Martha; Wilson, Mark; Clark, Mike; Nanan, Bobby; Matson, Liz; McBirney, Dick; Smith, Jay; Earle, Paul; Choi, Mike;
2014-01-01
The GeoCAPE Filter Radiometer (FR) Study is a different instrument type than all of the previous IDL GeoCape studies. The customer primary goals are to keep mass, volume and cost to a minimum while meeting the science objectives and maximizing flight opportunities by fitting on the largest number of GEO accommodations possible. Minimize total mission costs by riding on a commercial GEO satellite. For this instrument type, the coverage rate, km 2 min, was significantly increased while reducing the nadir ground sample size to 250m. This was accomplished by analyzing a large 2d area for each integration period. The field of view will be imaged on a 4k x 4k detector array of 15 micrometer pixels. Each ground pixel is spread over 2 x 2 detector pixels so the instantaneous field of view (IFOV) is 2048 X 2048 ground pixels. The baseline is, for each field of view 50 sequential snapshot images are taken, each with a different filter, before indexing the scan mirror to the next IFOV. A delta would be to add additional filters.
NASA Technical Reports Server (NTRS)
Matney, M.; Barker, E.; Seitzer, P.; Abercromby, K. J.; Rodriquez, H. M.
2006-01-01
NASA's Orbital Debris measurements program has a goal to characterize the small debris environment in the geosynchronous Earth-orbit (GEO) region using optical telescopes ("small" refers to objects too small to catalog and track with current systems). Traditionally, observations of GEO and near-GEO objects involve following the object with the telescope long enough to obtain an orbit suitable for tracking purposes. Telescopes operating in survey mode, however, randomly observe objects that pass through their field of view. Typically, these short-arc observation are inadequate to obtain detailed orbits, but can be used to estimate approximate circular orbit elements (semimajor axis, inclination, and ascending node). From this information, it should be possible to make statistical inferences about the orbital distributions of the GEO population bright enough to be observed by the system. The Michigan Orbital Debris Survey Telescope (MODEST) has been making such statistical surveys of the GEO region for four years. During that time, the telescope has made enough observations in enough areas of the GEO belt to have had nearly complete coverage. That means that almost all objects in all possible orbits in the GEO and near- GEO region had a non-zero chance of being observed. Some regions (such as those near zero inclination) have had good coverage, while others are poorly covered. Nevertheless, it is possible to remove these statistical biases and reconstruct the orbit populations within the limits of sampling error. In this paper, these statistical techniques and assumptions are described, and the techniques are applied to the current MODEST data set to arrive at our best estimate of the GEO orbit population distribution.
Path Network Recovery Using Remote Sensing Data and Geospatial-Temporal Semantic Graphs
DOE Office of Scientific and Technical Information (OSTI.GOV)
William C. McLendon III; Brost, Randy C.
Remote sensing systems produce large volumes of high-resolution images that are difficult to search. The GeoGraphy (pronounced Geo-Graph-y) framework [2, 20] encodes remote sensing imagery into a geospatial-temporal semantic graph representation to enable high level semantic searches to be performed. Typically scene objects such as buildings and trees tend to be shaped like blocks with few holes, but other shapes generated from path networks tend to have a large number of holes and can span a large geographic region due to their connectedness. For example, we have a dataset covering the city of Philadelphia in which there is a singlemore » road network node spanning a 6 mile x 8 mile region. Even a simple question such as "find two houses near the same street" might give unexpected results. More generally, nodes arising from networks of paths (roads, sidewalks, trails, etc.) require additional processing to make them useful for searches in GeoGraphy. We have assigned the term Path Network Recovery to this process. Path Network Recovery is a three-step process involving (1) partitioning the network node into segments, (2) repairing broken path segments interrupted by occlusions or sensor noise, and (3) adding path-aware search semantics into GeoQuestions. This report covers the path network recovery process, how it is used, and some example use cases of the current capabilities.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
St. Onge, Melinda
The Geothermal Resource Portfolio Optimization and Reporting Tool (GeoRePORT) was developed as a way to distill large amounts of geothermal project data into an objective, reportable data set that can be used to communicate with experts and non-experts. GeoRePORT summarizes (1) resource grade and certainty and (2) project readiness. This Excel file allows users to easily navigate through the resource grade attributes, using drop-down menus to pick grades and project readiness, and then easily print and share the summary with others. This spreadsheet is the first draft, for which we are soliciting expert feedback. The spreadsheet will be updated basedmore » on this feedback to increase usability of the tool. If you have any comments, please feel free to contact us.« less
Cohort profile: the Geoscience and Health Cohort Consortium (GECCO) in the Netherlands.
Timmermans, Erik J; Lakerveld, Jeroen; Beulens, Joline W J; Boomsma, Dorret I; Kramer, Sophia E; Oosterman, Mirjam; Willemsen, Gonneke; Stam, Mariska; Nijpels, Giel; Schuengel, Carlo; Smit, Jan H; Brunekreef, Bert; Dekkers, Jasper E C; Deeg, Dorly J H; Penninx, Brenda W J H; Huisman, Martijn
2018-06-09
In the Netherlands, a great variety of objectively measured geo-data is available, but these data are scattered and measured at varying spatial and temporal scales. The centralisation of these geo-data and the linkage of these data to individual-level data from longitudinal cohort studies enable large-scale epidemiological research on the impact of the environment on public health in the Netherlands. In the Geoscience and Health Cohort Consortium (GECCO), six large-scale and ongoing cohort studies have been enriched with a variety of existing geo-data. Here, we introduce GECCO by describing: (1) the phenotypes of the involved cohort studies, (2) the collected geo-data and their sources, (3) the methodology that was used to link the collected geo-data to individual cohort studies, (4) the similarity of commonly used geo-data between our consortium and the nationwide situation in the Netherlands and (5) the distribution of geo-data within our consortium. GECCO includes participants from six prospective cohort studies (eg, 44 657 respondents (18-100 years) in 2006) and it covers all municipalities in the Netherlands. Using postal code information of the participants, geo-data on the address-level, postal code-level as well as neighbourhood-level could be linked to individual-level cohort data. The geo-data could be successfully linked to almost all respondents of all cohort studies, with successful data-linkage rates ranging from 97.1% to 100.0% between cohort studies. The results show variability in geo-data within and across cohorts. GECCO increases power of analyses, provides opportunities for cross-checking and replication, ensures sufficient geographical variation in environmental determinants and allows for nuanced analyses on specific subgroups. GECCO offers unique opportunities for (longitudinal) studies on the complex relationships between the environment and health outcomes. For example, GECCO will be used for further research on environmental determinants of physical/psychosocial functioning and lifestyle behaviours. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
The Small Size Debris Population at GEO from Optical Observations
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Barker, Ed; Buckalew, Brent; Burkhardt, Andrew; Cowardin, Heather; Frith, James; Kaleida, Catherine; Lederer, Susan M.; Lee, Chris H.
2017-01-01
We have observed the geosynchronous orbit (GEO) debris population at sizes smaller than 10 cm using optical observations with the 6.5-m Magellan telescope 'Walter Baade' at the Las Campanas Observatory in Chile. The IMACS f/2 imaging camera with a 0.5-degree diameter field of view has been used in small area surveys of the GEO regime to study the population of optically faint GEO debris. The goal is to estimate the population of GEO debris that is fainter than can be studied with 1-meter class telescopes. A significant population of objects fainter than R = 19th magnitude has been found. These objects have observed with angular rates consistent with circular orbits and orbital inclinations up to 15 degrees at GEO. A sizeable number of these objects have significant brightness variations ("flashes") during the 5-second exposure, which suggest rapid changes in the albedo-projected size product.
GEO Supersites Data Exploitation Platform
NASA Astrophysics Data System (ADS)
Lengert, W.; Popp, H.-J.; Gleyzes, J.-P.
2012-04-01
In the framework of the GEO Geohazard Supersite initiative, an international partnership of organizations and scientists involved in the monitoring and assessment of geohazards has been established. The mission is to advance the scientific understanding of geohazards by improving geohazard monitoring through the combination of in-situ and space-based data, and by facilitating the access to data relevant for geohazard research. The stakeholders are: (1) governmental organizations or research institutions responsible for the ground-based monitoring of earthquake and volcanic areas, (2) space agencies and satellite operators providing satellite data, (3) the global geohazard scientific community. The 10.000's of ESA's SAR products are accessible, since beginning 2008, using ESA's "Virtual Archive", a Cloud Computing assets, allowing the global community an utmost downloading performance of these high volume data sets for mass-market costs. In the GEO collaborative context, the management of ESA's "Virtual Archive" and the ordering of these large data sets is being performed by UNAVCO, who is also coordinating the data demand for the several hundreds of co-PIs. ESA is envisaging to provide scientists and developers access to a highly elastic operational e-infrastructure, providing interdisciplinary data on a large scale as well as tools ensuring innovation and a permanent evolution of the products. Consequently, this science environment will help in defining and testing new applications and technologies fostering innovation and new science findings. In Europe, the collaboration between EPOS, "European Plate Observatory System" lead by INGV, and ESA with support of DLR, ASI, and CNES are the main institutional stakeholders for the GEO Supersites contributing also to a unifying e-infrastructure. The overarching objective of the Geohazard Supersites is: "To implement a sustainable Global Earthquake Observation System and a Global Volcano Observation System as part of the Global Earth Observation System of Systems (GEOSS)." This presentation will outline the overall concept, objectives, and examples of the e-infrastructure, which is currently being set up for the GEO Supersite initiative helping to advance science.
Photometric Studies of GEO Debris
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Cowardin, Heather M.; Barker, Edwin; Abercromby, Kira J.; Foreman, Gary; Horstman, Matt
2009-01-01
The photometric signature of a debris object can be useful in determining what the physical characteristics of a piece of debris are. We report on optical observations in multiple filters of debris at geosynchronous Earth orbit (GEO). Our sample is taken from GEO objects discovered in a survey with the University of Michigan's 0.6-m aperture Schmidt telescope MODEST (for Michigan Orbital DEbris Survey Telescope), and then followed up in real-time with the SMARTS (Small and Medium Aperture Research Telescope System) 0.9-m at CTIO for orbits and photometry. Our goal is to determine 6 parameter orbits and measure colors for all objects fainter than R = 15 th magnitude that are discovered in the MODEST survey. At this magnitude the distribution of observed angular rates changes significantly from that of brighter objects. There are two objectives: 1. Estimate the orbital distribution of objects selected on the basis of two observational criteria: brightness (magnitude) and angular rates. 2. Obtain magnitudes and colors in standard astronomical filters (BVRI) for comparison with reflectance spectra of likely spacecraft materials. What is the faint debris likely to be? In this paper we report on the photometric results. For a sample of 50 objects, more than 90 calibrated sequences of R-B-V-I-R magnitudes have been obtained with the CTIO 0.9-m. For objects that do not show large brightness variations, the colors are largely redder than solar in both B-R and R-I. The width of the color distribution may be intrinsic to the nature of the surfaces, but also could be that we are seeing irregularly shaped objects and measuring the colors at different times with just one telescope. For a smaller sample of objects we have observed with synchronized CCD cameras on the two telescopes. The CTIO 0.9-m observes in B, and MODEST in R. The CCD cameras are electronically linked together so that the start time and duration of observations are the same to better than 50 milliseconds. Thus the B-R color is a true measure of the surface of the debris piece facing the telescopes for that observation. Any change in color reflects a real change in the debris surface.
Photometric Studies of GEO Orbital Debris
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Rodriquez-Cowardin, Heather M.; Barker, Ed; Abercromby, Kira J.; Foreman, Gary; Horstman, Matt
2009-01-01
The photometric signature of a debris object can be useful in determining what the physical characteristics of a piece of debris are. We report on optical observations in multiple filters of debris at geosynchronous Earth orbit (GEO). Our sample is taken from GEO objects discovered in a survey with the University of Michigan's 0.6-m aperture Schmidt telescope MODEST (for Michigan Orbital DEbris Survey Telescope), and then followed up in real-time with the Cerro Tololo Inter- American Observatory (CTIO) 0.9-m for orbits and photometry. Our goal is to determine 6 parameter orbits and measure colors for all objects fainter than R=15th magnitude that are discovered in the MODEST survey. At this magnitude the distribution of observed angular rates changes significantly from that of brighter objects. There are two objectives: 1. Estimate the orbital distribution of objects selected on the basis of two observational criteria: brightness (magnitude) and angular rates. 2. Obtain magnitudes and colors in standard astronomical filters (BVRI) for comparison with reflectance spectra of likely spacecraft materials. What is the faint debris likely to be? More than 90 calibrated sequences of R-B-V-I-R magnitudes for a sample of 50 objects have been obtained with the CTIO 0.9-m. For objects that do not show large brightness variations, the colors are largely redder than solar in both B-R and R-I. The width of the color distribution may be intrinsic to the nature of the surfaces, but also could be that we are seeing irregularly shaped objects and measuring the colors at different times with just one telescope. For a smaller sample of objects we have observed with synchronized CCD cameras on the two telescopes. The CTIO 0.9-m observes in B, and MODEST in R. The CCD cameras are electronically linked together so that the start time and duration of observations are the same to better than 50 milliseconds. Thus the B-R color is a true measure of the surface of the debris piece facing the telescopes for that observation. Any change in color reflects a real change in the debris surface. We will compare our observations with models and laboratory measurements of selected surfaces.
Building a Billion Spatio-Temporal Object Search and Visualization Platform
NASA Astrophysics Data System (ADS)
Kakkar, D.; Lewis, B.
2017-10-01
With funding from the Sloan Foundation and Harvard Dataverse, the Harvard Center for Geographic Analysis (CGA) has developed a prototype spatio-temporal visualization platform called the Billion Object Platform or BOP. The goal of the project is to lower barriers for scholars who wish to access large, streaming, spatio-temporal datasets. The BOP is now loaded with the latest billion geo-tweets, and is fed a real-time stream of about 1 million tweets per day. The geo-tweets are enriched with sentiment and census/admin boundary codes when they enter the system. The system is open source and is currently hosted on Massachusetts Open Cloud (MOC), an OpenStack environment with all components deployed in Docker orchestrated by Kontena. This paper will provide an overview of the BOP architecture, which is built on an open source stack consisting of Apache Lucene, Solr, Kafka, Zookeeper, Swagger, scikit-learn, OpenLayers, and AngularJS. The paper will further discuss the approach used for harvesting, enriching, streaming, storing, indexing, visualizing and querying a billion streaming geo-tweets.
The Population of Optically Faint GEO Debris
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Barker, Ed; Buckalew, Brent; Burkhardt, Andrew; Cowardin, Heather; Frith, James; Gomez, Juan; Kaleida, Catherine; Lederer, Susan M.; Lee, Chris H.
2016-01-01
The 6.5-m Magellan telescope 'Walter Baade' at the Las Campanas Observatory in Chile has been used for spot surveys of the GEO orbital regime to study the population of optically faint GEO debris. The goal is to estimate the size of the population of GEO debris at sizes much smaller than can be studied with 1-meter class telescopes. Despite the small size of the field of view of the Magellan instrument (diameter 0.5-degree), a significant population of objects fainter than R = 19th magnitude have been found with angular rates consistent with circular orbits at GEO. We compare the size of this population with the numbers of GEO objects found at brighter magnitudes by smaller telescopes. The observed detections have a wide range in characteristics starting with those appearing as short uniform streaks. But there are a substantial number of detections with variations in brightness, flashers, during the 5-second exposure. The duration of each of these flashes can be extremely brief: sometimes less than half a second. This is characteristic of a rapidly tumbling object with a quite variable projected size times albedo. If the albedo is of the order of 0.2, then the largest projected size of these objects is around 10-cm. The data in this paper was collected over the last several years using Magellan's IMACS camera in f/2 mode. The analysis shows the brightness bins for the observed GEO population as well as the periodicity of the flashers. All objects presented are correlated with the catalog: the focus of the paper will be on the uncorrelated, optically faint, objects. The goal of this project is to better characterize the faint debris population in GEO that access to a 6.5-m optical telescope in a superb site can provide.
Effects of optical and geometrical properties on YORP effect for inactive satellites
NASA Astrophysics Data System (ADS)
Albuja, A.; Scheeres, D.
2014-09-01
With the increasing number of space debris in Earth orbit, it is important to understand the dynamics of these objects. Initial studies have demonstrated that the Yarkovsky, O'Keefe, Radzievskii, Paddack (YORP) effect on inactive satellite needs to be further explored as it could be noticeably affecting the rotational dynamics of these Earth orbiting objects. The YORP effect is created by torques resulting from light and thermal energy being re-emitted from the surface of a body. This effect has been well studied and observed to affect the spin states of asteroids. The purpose of this paper is to further investigate YORP in the realm of large inactive Geosynchronous Earth Orbit (GEO) satellites. The forces that cause the YORP effect are highly dependent on the optical, thermal and geometrical properties of the facets making up the surface of the body being analyzed. This paper focuses on exploring the effect of these properties on the YORP effect for inactive satellite. Two different satellite models that represent bus types of inactive satellites in GEO are used for this study. By varying the optical, thermal and geometrical properties of these models, in a manner that remains consistent with realistic satellite parameters, we can understand the relationship between these properties and the torques created by YORP. Having this knowledge allows for better understanding of the possible attitude states (spin rate and obliquity) for uncontrolled satellites in GEO. This information can then be used to make predictions of the long-term behavior of the rotation rate and obliquity of these objects. Categories of potential final states for defunct GEO satellites can then be created based on geometrical and optical properties (e.g. spin up continuously, spin down continuously, etc.). This allows the population of inactive GEO satellites to be studied in a more general sense and final attitude states for these objects can be quickly identified. Furthermore, an understanding of the sensitivity of YORP to each individual parameter is gained through this paper. Having knowledge of the attitude dynamics for these objects is key for accurate prediction of the orbital dynamics as these two are closely coupled when torques such as YORP are acting on the body.
A Simple Model for the Orbital Debris Environment in GEO
NASA Astrophysics Data System (ADS)
Anilkumar, A. K.; Ananthasayanam, M. R.; Subba Rao, P. V.
The increase of space debris and its threat to commercial space activities in the Geosynchronous Earth Orbit (GEO) predictably cause concern regarding the environment over the long term. A variety of studies regarding space debris such as detection, modeling, protection and mitigation measures, is being pursued for the past couple of decades. Due to the absence of atmospheric drag to remove debris in GEO and the increasing number of utility satellites therein, the number of objects in GEO will continue to increase. The characterization of the GEO environment is critical for risk assessment and protection of future satellites and also to incorporate effective debris mitigation measures in the design and operations. The debris measurements in GEO have been limited to objects with size more than 60 cm. This paper provides an engineering model of the GEO environment by utilizing the philosophy and approach as laid out for the SIMPLE model proposed recently for LEO by the authors. The present study analyses the statistical characteristics of the GEO catalogued objects in order to arrive at a model for the GEO space debris environment. It is noted that the catalogued objects, as of now of around 800, by USSPACECOM across the years 1998 to 2004 have the same semi major axis mode (highest number density) around 35750 km above the earth. After removing the objects in the small bin around the mode, (35700, 35800) km containing around 40 percent (a value that is nearly constant across the years) of the objects, the number density of the other objects follow a single Laplace distribution with two parameters, namely location and scale. Across the years the location parameter of the above distribution does not significantly vary but the scale parameter shows a definite trend. These observations are successfully utilized in proposing a simple model for the GEO debris environment. References Ananthasayanam, M. R., Anil Kumar, A. K., and Subba Rao, P. V., ``A New Stochastic Impressionistic Low Earth (SIMPLE) Model of the Space Debris Scenario'', Conference Abstract COSPAR 02-A-01772, 2002. Ananthasayanam, M. R., Anilkumar, A. K., Subba Rao, P. V., and V. Adimurthy, ``Characterization of Eccentricity and Ballistic Coefficients of Space Debris in Altitude and Perigee Bins'', IAC-03-IAA5.p.04, Presented at the IAF Conference, Bremen, October 2003 and also to be published in the Proceedings of IAF Conference, Science and Technology Series, 2003.
NASA Astrophysics Data System (ADS)
Hu, Yun-peng; Chen, Lei; Huang, Jian-yu
2017-08-01
The US Lincoln Laboratory proved that space-based visible (SBV) observation is efficient to observe space objects, especially Geosynchronous Orbit (GEO) objects. After that, SBV observation plays an important role in the space surveillance. In this paper, a novel space-based observation mode is designed to observe all the GEO objects in a relatively short time. A low earth orbit (LEO) satellite, especially a dawn-dusk sun-synchronous orbit satellite, is useful for space-based observation. Thus, the observation mode for GEO objects is based on a dawn-dusk sun-synchronous orbit satellite. It is found that the Pinch Point (PP) regions proposed by the US Lincoln Laboratory are spreading based on the analysis of the evolution principles of GEO objects. As the PP regions becoming more and more widely in the future, many strategies based on it may not be efficient any more. Hence, the key point of the space-based observation strategy design for GEO objects should be emphasized on the whole GEO belt as far as possible. The pseudo-fixed latitude observation mode is proposed in this paper based on the characteristics of GEO belt. Unlike classical space-based observation modes, pseudo-fixed latitude observation mode makes use of the one-dimensional attitude adjustment of the observation satellite. The pseudo-fixed latitude observation mode is more reliable and simple in engineering, compared with the gazing observation mode which needs to adjust the attitude from the two dimensions. It includes two types of attitude adjustment, i.e. daily and continuous attitude adjustment. Therefore, the pseudo-fixed latitude observation mode has two characteristics. In a day, the latitude of the observation region is fixed and the scanning region is about a rectangle, while the latitude of the observation region centre changes each day in a long term based on a daily strategy. The capabilities of a pseudo-fixed latitude observation instrument with a 98° dawn-dusk sun-synchronous orbit are discussed. It is found that most of GEO objects can be visited every day and almost all the GEO objects can be visited in two days in the whole year using a sensor with 20°×2° field of view (FOV). The seasonal drops, which are caused by the characteristics of GEO belt and the influence of earth shadow at the two equinoxes, have been overcome under the pseudo-fixed observation mode.
NASA Astrophysics Data System (ADS)
Frith, J.; Barker, E.; Cowardin, H.; Buckalew, B.; Anz-Meador, P.; Lederer, S.
The National Aeronautics and Space Administration (NASA) Orbital Debris Program Office (ODPO) recently commissioned the Meter Class Autonomous Telescope (MCAT) on Ascension Island with the primary goal of obtaining population statistics of the geosynchronous (GEO) orbital debris environment. To help facilitate this, studies have been conducted using MCAT’s known and projected capabilities to estimate the accuracy and timeliness in which it can survey the GEO environment, including collected weather data and the proposed observational data collection cadence. To optimize observing cadences and probability of detection, on-going work using a simulated GEO debris population sampled at various cadences are run through the Constrained Admissible Region Multi Hypotheses Filter (CAR-MHF). The orbits computed from the results are then compared to the simulated data to assess MCAT’s ability to determine accurately the orbits of debris at various sample rates. The goal of this work is to discriminate GEO and near-GEO objects from GEO transfer orbit objects that can appear as GEO objects in the environmental models due to the short arc observation and an assumed circular orbit. The specific methods and results are presented here.
Estimation of Untracked Geosynchronous Population from Short-Arc Angles-Only Observations
NASA Technical Reports Server (NTRS)
Healy, Liam; Matney, Mark
2017-01-01
Telescope observations of the geosynchronous regime will observe two basic types of objects --- objects related to geosynchronous earth orbit (GEO) satellites, and objects in highly elliptical geosynchronous transfer orbits (GTO). Because telescopes only measure angular rates, the GTO can occasionally mimic the motion of GEO objects over short arcs. A GEO census based solely on short arc telescope observations may be affected by these ``interlopers''. A census that includes multiple angular rates can get an accurate statistical estimate of the GTO population, and that then can be used to correct the estimate of the geosynchronous earth orbit population.
Gravity model improvement using GEOS 3 /GEM 9 and 10/. [and Seasat altimetry data
NASA Technical Reports Server (NTRS)
Lerch, F. J.; Wagner, C. A.; Klosko, S. M.; Laubscher, R. E.
1979-01-01
Although errors in previous gravity models have produced large uncertainties in the orbital position of GEOS 3, significant improvement has been obtained with new geopotential solutions, Goddard Earth Model (GEM) 9 and 10. The GEM 9 and 10 solutions for the potential coefficients and station coordinates are presented along with a discussion of the new techniques employed. Also presented and discussed are solutions for three fundamental geodetic reference parameters, viz. the mean radius of the earth, the gravitational constant, and mean equatorial gravity. Evaluation of the gravity field is examined together with evaluation of GEM 9 and 10 for orbit determination accuracy. The major objectives of GEM 9 and 10 are achieved. GEOS 3 orbital accuracies from these models are about 1 m in their radial components for 5-day arc lengths. Both models yield significantly improved results over GEM solutions when compared to surface gravimetry, Skylab and GEOS 3 altimetry, and highly accurate BE-C (Beacon Explorer-C) laser ranges. The new values of the parameters discussed are given.
Photometric Studies of Orbital Debris at GEO
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Abercromby, Kira J.; Rodriguez-Cowardin, Heather M.; Barker, Ed; Foreman, Gary; Horstman, Matt
2009-01-01
We report on optical observations of debris at geosynchronous Earth orbit (GEO) using two telescopes simultaneously at the Cerro Tololo Inter-American Observatory (CTIO) in Chile. The University of Michigan s 0.6/0.9-m Schmidt telescope MODEST (for Michigan Orbital DEbris Survey Telescope) was used in survey mode to find objects that potentially could be at GEO. Because GEO objects only appear in this telescope s field of view for an average of 5 minutes, a full six-parameter orbit can not be determined. Interrupting the survey for follow-up observations leads to incompleteness in the survey results. Instead, as objects are detected with MODEST, initial predictions assuming a circular orbit are done for where the object will be for the next hour, and the objects are reacquired as quickly as possible on the CTIO 0.9-m telescope. This second telescope follows-up during the first night and, if possible, over several more nights to obtain the maximum time arc possible, and the best six parameter orbit. Our goal is to obtain an initial orbit and calibrated colors for all detected objects fainter than R = 15th in order to estimate the orbital distribution of objects selected on the basis of two observational criteria: magnitude and angular rate. One objective is to estimate what fraction of objects selected on the basis of angular rate are not at GEO. A second objective is to obtain magnitudes and colors in standard astronomical filters (BVRI) for comparison with reflectance spectra of likely spacecraft materials.
Application of 3D Spatio-Temporal Data Modeling, Management, and Analysis in DB4GEO
NASA Astrophysics Data System (ADS)
Kuper, P. V.; Breunig, M.; Al-Doori, M.; Thomsen, A.
2016-10-01
Many of todaýs world wide challenges such as climate change, water supply and transport systems in cities or movements of crowds need spatio-temporal data to be examined in detail. Thus the number of examinations in 3D space dealing with geospatial objects moving in space and time or even changing their shapes in time will rapidly increase in the future. Prominent spatio-temporal applications are subsurface reservoir modeling, water supply after seawater desalination and the development of transport systems in mega cities. All of these applications generate large spatio-temporal data sets. However, the modeling, management and analysis of 3D geo-objects with changing shape and attributes in time still is a challenge for geospatial database architectures. In this article we describe the application of concepts for the modeling, management and analysis of 2.5D and 3D spatial plus 1D temporal objects implemented in DB4GeO, our service-oriented geospatial database architecture. An example application with spatio-temporal data of a landfill, near the city of Osnabrück in Germany demonstrates the usage of the concepts. Finally, an outlook on our future research focusing on new applications with big data analysis in three spatial plus one temporal dimension in the United Arab Emirates, especially the Dubai area, is given.
Effects of perturbations on space debris in supersynchronous storage orbits
NASA Astrophysics Data System (ADS)
Luu, Khanh Kim
1998-12-01
Accumulation of space debris in the geosynchronous region (GEO) has raised attention among spacefaring nations. The current mitigation measure supported is to boost satellites into supersynchronous orbits in the time before station-keeping fuel is expected to be exhausted. Because this solution does not remove mass from space, debris generation by fragmentation events remains a possibility. The collision hazard between inactive satellites in the supersynchronous region raises questions about the consequences of collisions in this regime and possible interaction with GEO. In considering the use of supersynchronous orbits for satellite disposal, the first concern is to determine the minimum safe distance above GEO such that objects in the disposal orbits will not interfere with the GEO population in the future. This involves defining the useful GEO area and studying the perturbation effects on objects in supersynchronous orbits. Thus far, research has focused on propagating the orbits of intact objects. However, in the aftermath of a collision, pieces of varying sizes and shapes can be found in orbits quite different from the parent objects' orbits. This document summarizes background information on debris in the GEO region, sources and management strategies, and then addresses the problem: Will orbits of fragments from a collision in a storage orbit occupy GEO altitudes at some time after the collision? If so, at what altitude should the storage orbit occupy such that collision fragments will not interfere with the GEO population? The methods and tools by which the effects of collisions in the supersynchronous region can be analyzed are discussed. A low-velocity collision model is employed to provide delta-velocities imparted to the fragments. An analytical study of perturbation effects, including solar and lunar third body gravitation, Earth oblateness through degree and order four, and solar radiation pressure, follows in order to evaluate the magnitude of these disturbing forces on the fragmentation debris. Validation of these results by numerical analysis using proven numerical and semianalytical orbit propagators is discussed. The results show that currently practiced reorbiting distances above GEO do not isolate debris from GEO after the occurrence of collisions in the storage orbit.
Evaluating the Potential of the GeoWall for Geographic Education
ERIC Educational Resources Information Center
Slocum, Terry A.; Dunbar, Matthew D.; Egbert, Stephen L.
2007-01-01
This article discusses modern stereoscopic displays for geographic education, focusing on a large-format display--the GeoWall. To evaluate the potential of the GeoWall, geography instructors were asked to express their reactions to images viewed on the GeoWall during a focus group experiment. Instructors overwhelmingly supported using the GeoWall,…
Crowd-sourced pictures geo-localization method based on street view images and 3D reconstruction
NASA Astrophysics Data System (ADS)
Cheng, Liang; Yuan, Yi; Xia, Nan; Chen, Song; Chen, Yanming; Yang, Kang; Ma, Lei; Li, Manchun
2018-07-01
People are increasingly becoming accustomed to taking photos of everyday life in modern cities and uploading them on major photo-sharing social media sites. These sites contain numerous pictures, but some have incomplete or blurred location information. The geo-localization of crowd-sourced pictures enriches the information contained therein, and is applicable to activities such as urban construction, urban landscape analysis, and crime tracking. However, geo-localization faces huge technical challenges. This paper proposes a method for large-scale geo-localization of crowd-sourced pictures. Our approach uses structured, organized Street View images as a reference dataset and employs a three-step strategy of coarse geo-localization by image retrieval, selecting reliable matches by image registration, and fine geo-localization by 3D reconstruction to attach geographic tags to pictures from unidentified sources. In study area, 3D reconstruction based on close-range photogrammetry is used to restore the 3D geographical information of the crowd-sourced pictures, resulting in the proposed method improving the median error from 256.7 m to 69.0 m, and the percentage of the geo-localized query pictures under a 50 m error from 17.2% to 43.2% compared with the previous method. Another discovery using the proposed method is that, in respect of the causes of reconstruction error, closer distances from the cameras to the main objects in query pictures tend to produce lower errors and the component of error parallel to the road makes a more significant contribution to the Total Error. The proposed method is not limited to small areas, and could be expanded to cities and larger areas owing to its flexible parameters.
Adaption from LWIR to visible wavebands of methods to describe the population of GEO belt debris
NASA Astrophysics Data System (ADS)
Meng, Kevin; Murray-Krezan, Jeremy; Seitzer, Patrick
2018-05-01
Prior efforts to characterize the number of GEO belt debris objects by statistically analyzing the distribution of debris as a function of size have relied on techniques unique to infrared measurements of the debris. Specifically the infrared measurement techniques permitted inference of the characteristic size of the debris. This report describes a method to adapt the previous techniques and measurements to visible wavebands. Results will be presented using data from a NASA optical, visible band survey of objects near the geosynchronous orbit, GEO belt. This survey used the University of Michigan's 0.6-m Curtis-Schmidt telescope, Michigan Orbital DEbris Survey Telescope (MODEST), located at Cerro Tololo Inter-American Observatory in Chile. The system is equipped with a scanning CCD with a field of view of 1.6°×1.6°, and can detect objects smaller than 20 cm diameter at GEO.
A method of constructing geo-object ontology in disaster system for prevention and decrease
NASA Astrophysics Data System (ADS)
Li, Bin; Liu, Jiping; Shi, Lihong; Wang, Zhenfeng
2009-10-01
A kind of formal system, which can express clearly a certain entity or information, is needed to express geographical concept. Besides, some rules explaining the interrelationship and action between different components are also required. Therefore, the conception of geo-object ontology is introduced. It is a shared formalization and display specification of conceptual knowledge system in the field of concrete application of spatial information science. It can constitute hierarchy structure, which derives from the concept classification system in the geographical area. Its concepts can be described by the property. Property sets can form a vector space with multi-dimensional characteristics. Geographic space is composed of different types of geographic entities. And its concept is formed by a series of geographic entities with the same properties and actions. Moreover, each of the geographic entities can be mapped to an object, and each object has its spatial property, time information and topology, semantic relationships associated with other objects. The biggest difference between ecumenical information ontology and geo-ontology is that the latter has the spatial characteristics. During the construction process of geo-object ontology, some important components, such as geographic type, spatial relation, spatial entity type and coordinates, time, should be included to make further research. Here, taking disaster as an example, by using Protégé and OWL, combined methods used by constructing the geo-object ontology in the form of being manual made by domanial experts and semi-automatic are investigated oriented to disaster to serve ultimately geographic information retrieval service driven by ontology.
Improved Estimation of Orbits and Physical Properties of Objects in GEO
NASA Astrophysics Data System (ADS)
Bradley, B.; Axelrad, P.
2013-09-01
Orbital debris is a major concern for satellite operators, both commercial and military. Debris in the geosynchronous (GEO) belt is of particular concern because this unique region is such a valuable, limited resource, and, from the ground we cannot reliably track and characterize GEO objects smaller than 1 meter in diameter. Space-based space surveillance (SBSS) is required to observe GEO objects without weather restriction and with improved viewing geometry. SBSS satellites have thus far been placed in Sun-synchronous orbits. This paper investigates the benefits to GEO orbit determination (including the estimation of mass, area, and shape) that arises from placing observing satellites in geosynchronous transfer orbit (GTO) and a sub-GEO orbit. Recently, several papers have reported on simulation studies to estimate orbits and physical properties; however, these studies use simulated objects and ground-based measurements, often with dense and long data arcs. While this type of simulation provides valuable insight into what is possible, as far as state estimation goes, it is not a very realistic observing scenario and thus may not yield meaningful accuracies. Our research improves upon simulations published to date by utilizing publicly available ephemerides for the WAAS satellites (Anik F1R and Galaxy 15), accurate at the meter level. By simulating and deliberately degrading right ascension and declination observations, consistent with these ephemerides, a realistic assessment of the achievable orbit determination accuracy using GTO and sub-GEO SBSS platforms is performed. Our results show that orbit accuracy is significantly improved as compared to a Sun-synchronous platform. Physical property estimation is also performed using simulated astrometric and photometric data taken from GTO and sub-GEO sensors. Simulations of SBSS-only as well as combined SBSS and ground-based observation tracks are used to study the improvement in area, mass, and shape estimation gained by the proposed systems. Again our work improves upon previous research by investigating realistic observation scheduling scenarios to gain insight into achievable accuracies.
Observations of GEO Debris with the Magellan 6.5-m Telescopes
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Burkhardt, Andrew; Cardonna, Tommaso; Lederer, Susan M.; Cowardin, Heather; Barker, Edwin S.; Abercromby, Kira J.
2012-01-01
Optical observations of geosynchronous orbit (GEO) debris are important to address two questions: 1. What is the distribution function of objects at GEO as a function of brightness? With some assumptions, this can be used to infer a size distribution. 2. Can we determine what the likely composition of individual GEO debris pieces is from studies of the spectral reflectance of these objects? In this paper we report on optical observations with the 6.5-m Magellan telescopes at Las Campanas Observatory in Chile that attempt to answer both questions. Imaging observations over a 0.5 degree diameter field-of-view have detected a significant population of optically faint debris candidates with R > 19th magnitude, corresponding to a size smaller than 20 cm assuming an albedo of 0.175. Many of these objects show brightness variations larger than a factor of 2, suggesting either irregular shapes or albedo variations or both. The object detection rate (per square degree per hour) shows an increase over the rate measured in the 0.6-m MODEST observations, implying an increase in the population at optically fainter levels. Assuming that the albedo distribution is the same for both samples, this corresponds to an increase in the population of smaller size debris. To study the second issue, calibrated reflectance spectroscopy has been obtained of a sample of GEO and near GEO objects with orbits in the public U.S. Space Surveillance Network catalog. With a 6.5-m telescope, the exposures times are short (30 seconds or less), and provide simultaneous wavelength coverage from 4500 to 8000 Angstroms. If the observed objects are tumbling, then simultaneous coverage and short exposure times are essential for a realistic assessment of the object fs spectral signature. We will compare the calibrated spectra with lab-based measurements of simple spacecraft surfaces composed of a single material.
GEO Optical Data Association with Concurrent Metric and Photometric Information
NASA Astrophysics Data System (ADS)
Dao, P.; Monet, D.
Data association in a congested area of the GEO belt with occasional visits by non-resident objects can be treated as a Multi-Target-Tracking (MTT) problem. For a stationary sensor surveilling the GEO belt, geosynchronous and near GEO objects are not completely motionless in the earth-fixed frame and can be observed as moving targets. In some clusters, metric or positional information is insufficiently accurate or up-to-date to associate the measurements. In the presence of measurements with uncertain origin, star tracks (residuals) and other sensor artifacts, heuristic techniques based on hard decision assignment do not perform adequately. In the MMT community, Bar-Shalom [2009 Bar-Shalom] was first in introducing the use of measurements to update the state of the target of interest in the tracking filter, e.g. Kalman filter. Following Bar-Shalom’s idea, we use the Probabilistic Data Association Filter (PDAF) but to make use of all information obtainable in the measurement of three-axis-stabilized GEO satellites, we combine photometric with metric measurements to update the filter. Therefore, our technique Concurrent Spatio- Temporal and Brightness (COSTB) has the stand-alone ability of associating a track with its identity –for resident objects. That is possible because the light curve of a stabilized GEO satellite changes minimally from night to night. We exercised COSTB on camera cadence data to associate measurements, correct mistags and detect non-residents in a simulated near real time cadence. Data on GEO clusters were used.
2015-09-30
Propagation and Geo -Acoustic Bottom Properties Harry A DeFerrari RSMAS – University of Miami 4600 Rickenbacker Causeway Miami FL. 33149...limited information about the ocean acoustic environment and the geo -acoustic properties of the bottom. The objective here is to measure the pulse...models and estimate the geo -acoustic properties of the bottom by inversion. APPROACH M-sequences have long been the workhorse of basic research
ERIC Educational Resources Information Center
Baltaci, Serdal; Yildiz, Avni
2015-01-01
Each new version of the GeoGebra dynamic mathematics software goes through updates and innovations. One of these innovations is the GeoGebra 5.0 version. This version aims to facilitate 3D instruction by offering opportunities for students to analyze 3D objects. While scanning the previous studies of GeoGebra 3D, it is seen that they mainly focus…
Technology Development and Demonstration Concepts for the Space Elevator
NASA Technical Reports Server (NTRS)
Smitherman, David V., Jr.
2004-01-01
During the 1990s several discoveries and advances in the development of carbon nano-tube (CNT) materials indicated that material strengths many times greater than common high-strength composite materials might be possible. Progress in the development of this material led to renewed interest in the space elevator concept for construction of a tether structure from the surface of the Earth through a geostationary orbit (GEO) and thus creating a new approach to Earth-to-orbit transportation infrastructures. To investigate this possibility the author, in 1999, managed for NASA a space elevator work:hop at the Marshall Space Flight Center to explore the potential feasibility of space elevators in the 21 century, and to identify the critical technologies and demonstration missions needed to make development of space elevators feasible. Since that time, a NASA Institute for Advanced Concepts (NIAC) funded study of the Space Elevator proposed a concept for a simpler first space elevator system using more near-term technologies. This paper will review some of the latest ideas for space elevator development, the critical technologies required, and some of the ideas proposed for demonstrating the feasibility for full-scale development of an Earth to GEO space elevator. Critical technologies include CNT composite materials, wireless power transmission, orbital object avoidance, and large-scale tether deployment and control systems. Numerous paths for technology demonstrations have been proposed utilizing ground experiments, air structures. LEO missions, the space shuttle, the international Space Station, GEO demonstration missions, demonstrations at the lunar L1 or L2 points, and other locations. In conclusion, this paper finds that the most critical technologies for an Earth to GEO space elevator include CNT composite materials development and object avoidance technologies; that lack of successful development of these technologies need not preclude continued development of space elevator systems in general; and that the critical technologies required for the Earth to GEO space elevator are not required for similar systems at the Moon, Mars, Europa, or for orbital tether systems at GEO, Luna, and other locations.
Optical Observation, Image-processing, and Detection of Space Debris in Geosynchronous Earth Orbit
NASA Astrophysics Data System (ADS)
Oda, H.; Yanagisawa, T.; Kurosaki, H.; Tagawa, M.
2014-09-01
We report on optical observations and an efficient detection method of space debris in the geosynchronous Earth orbit (GEO). We operate our new Australia Remote Observatory (ARO) where an 18 cm optical telescope with a charged-coupled device (CCD) camera covering a 3.14-degree field of view is used for GEO debris survey, and analyse datasets of successive CCD images using the line detection method (Yanagisawa and Nakajima 2005). In our operation, the exposure time of each CCD image is set to be 3 seconds (or 5 seconds), and the time interval of CCD shutter open is about 4.7 seconds (or 6.7 seconds). In the line detection method, a sufficient number of sample objects are taken from each image based on their shape and intensity, which includes not only faint signals but also background noise (we take 500 sample objects from each image in this paper). Then we search a sequence of sample objects aligning in a straight line in the successive images to exclude the noise sample. We succeed in detecting faint signals (down to about 1.8 sigma of background noise) by applying the line detection method to 18 CCD images. As a result, we detected about 300 GEO objects up to magnitude of 15.5 among 5 nights data. We also calculate orbits of objects detected using the Simplified General Perturbations Satellite Orbit Model 4(SGP4), and identify the objects listed in the two-line-element (TLE) data catalogue publicly provided by the U.S. Strategic Command (USSTRATCOM). We found that a certain amount of our detections are new objects that are not contained in the catalogue. We conclude that our ARO and detection method posse a high efficiency detection of GEO objects despite the use of comparatively-inexpensive observation and analysis system. We also describe the image-processing specialized for the detection of GEO objects (not for usual astronomical objects like stars) in this paper.
Large Diffractive Optics for GEo-Based Earth Surveillance
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hyde, R A
2003-09-11
The natural vantage point for performing Earth-centric operations from space is geosynchronous orbit (GEO); a platform there moves at the same rate as the Earth's surface, so appears to continually ''hover'' over a fixed site on the Earth. Unlike spacecraft in other orbits, which rapidly fly-over targets, a GEO-based platform remains in-position all the time. In order to insure continual access to sites using low earth orbit (LEO) platforms, one needs a large enough constellation ({approx} 50) of spacecraft so that one is always overhead; in contrast, a single GEO platform provides continuous coverage over sites throughout Euro-Asia. This permanentmore » coverage comes, unfortunately, with a stiff price-tag; geosynchronous orbit is 36,000 km high, so space platforms there must operate at ranges roughly 100 times greater than ones located in LEO. For optical-based applications, this extreme range is difficult to deal with; for surveillance the price is a 100-fold loss of resolution, for laser weapons it is a 10,000-fold loss in flux-on-target. These huge performance penalties are almost always unacceptable, preventing us from successfully using GEO-based platforms. In practice, we are forced to either settle for brief, infrequent access to targets, or, if we demand continuous coverage, to invest in large, many-satellite, constellations. There is, fortunately, a way to use GEO-based optical platforms without incurring the huge, range-dependent, performance penalties; one must simply use bigger optics. As long as the aperture of a platform's optics increases as much as its operating range, then its performance (resolution and/or flux) does not suffer; the price for operating from GEO is simply 100-fold larger optics. This is, of course, a very stiff price; while meter-class optics may suffice for many low-earth-orbit applications, 100 meter apertures are needed in order to achieve similar performance from GEO. Since even the largest Earth-based telescope is only 10 meters in diameter, building ten-fold larger ones for GEO applications (let alone delivering and operating them there) presents major difficulties. However, since the challenges of fielding large platforms in GEO are matched by the benefits of continuous coverage, we propose a program to develop such optical platforms. In this section, we will examine a particular form of large aperture optic, using a flat diffractive lens instead of the more conventional curved reflectors considered elsewhere in this report. We will discuss both the development of this type of large aperture optics, as well as the steps necessary to use it for GEO-based Earth surveillance. In a later section of this report we will discuss another use for large diffractive optics, their application for global-reach laser weapons.« less
GeoPAT: A toolbox for pattern-based information retrieval from large geospatial databases
NASA Astrophysics Data System (ADS)
Jasiewicz, Jarosław; Netzel, Paweł; Stepinski, Tomasz
2015-07-01
Geospatial Pattern Analysis Toolbox (GeoPAT) is a collection of GRASS GIS modules for carrying out pattern-based geospatial analysis of images and other spatial datasets. The need for pattern-based analysis arises when images/rasters contain rich spatial information either because of their very high resolution or their very large spatial extent. Elementary units of pattern-based analysis are scenes - patches of surface consisting of a complex arrangement of individual pixels (patterns). GeoPAT modules implement popular GIS algorithms, such as query, overlay, and segmentation, to operate on the grid of scenes. To achieve these capabilities GeoPAT includes a library of scene signatures - compact numerical descriptors of patterns, and a library of distance functions - providing numerical means of assessing dissimilarity between scenes. Ancillary GeoPAT modules use these functions to construct a grid of scenes or to assign signatures to individual scenes having regular or irregular geometries. Thus GeoPAT combines knowledge retrieval from patterns with mapping tasks within a single integrated GIS environment. GeoPAT is designed to identify and analyze complex, highly generalized classes in spatial datasets. Examples include distinguishing between different styles of urban settlements using VHR images, delineating different landscape types in land cover maps, and mapping physiographic units from DEM. The concept of pattern-based spatial analysis is explained and the roles of all modules and functions are described. A case study example pertaining to delineation of landscape types in a subregion of NLCD is given. Performance evaluation is included to highlight GeoPAT's applicability to very large datasets. The GeoPAT toolbox is available for download from
Topologically Consistent Models for Efficient Big Geo-Spatio Data Distribution
NASA Astrophysics Data System (ADS)
Jahn, M. W.; Bradley, P. E.; Doori, M. Al; Breunig, M.
2017-10-01
Geo-spatio-temporal topology models are likely to become a key concept to check the consistency of 3D (spatial space) and 4D (spatial + temporal space) models for emerging GIS applications such as subsurface reservoir modelling or the simulation of energy and water supply of mega or smart cities. Furthermore, the data management for complex models consisting of big geo-spatial data is a challenge for GIS and geo-database research. General challenges, concepts, and techniques of big geo-spatial data management are presented. In this paper we introduce a sound mathematical approach for a topologically consistent geo-spatio-temporal model based on the concept of the incidence graph. We redesign DB4GeO, our service-based geo-spatio-temporal database architecture, on the way to the parallel management of massive geo-spatial data. Approaches for a new geo-spatio-temporal and object model of DB4GeO meeting the requirements of big geo-spatial data are discussed in detail. Finally, a conclusion and outlook on our future research are given on the way to support the processing of geo-analytics and -simulations in a parallel and distributed system environment.
NASA Astrophysics Data System (ADS)
Chaudhary, A.
2017-12-01
Current simulation models and sensors are producing high-resolution, high-velocity data in geosciences domain. Knowledge discovery from these complex and large size datasets require tools that are capable of handling very large data and providing interactive data analytics features to researchers. To this end, Kitware and its collaborators are producing open-source tools GeoNotebook, GeoJS, Gaia, and Minerva for geosciences that are using hardware accelerated graphics and advancements in parallel and distributed processing (Celery and Apache Spark) and can be loosely coupled to solve real-world use-cases. GeoNotebook (https://github.com/OpenGeoscience/geonotebook) is co-developed by Kitware and NASA-Ames and is an extension to the Jupyter Notebook. It provides interactive visualization and python-based analysis of geospatial data and depending the backend (KTile or GeoPySpark) can handle data sizes of Hundreds of Gigabytes to Terabytes. GeoNotebook uses GeoJS (https://github.com/OpenGeoscience/geojs) to render very large geospatial data on the map using WebGL and Canvas2D API. GeoJS is more than just a GIS library as users can create scientific plots such as vector and contour and can embed InfoVis plots using D3.js. GeoJS aims for high-performance visualization and interactive data exploration of scientific and geospatial location aware datasets and supports features such as Point, Line, Polygon, and advanced features such as Pixelmap, Contour, Heatmap, and Choropleth. Our another open-source tool Minerva ((https://github.com/kitware/minerva) is a geospatial application that is built on top of open-source web-based data management system Girder (https://github.com/girder/girder) which provides an ability to access data from HDFS or Amazon S3 buckets and provides capabilities to perform visualization and analyses on geosciences data in a web environment using GDAL and GeoPandas wrapped in a unified API provided by Gaia (https://github.com/OpenDataAnalytics/gaia). In this presentation, we will discuss core features of each of these tools and will present lessons learned on handling large data in the context of data management, analyses and visualization.
NASA Astrophysics Data System (ADS)
Miao, Zelang
2017-04-01
Currently, urban dwellers comprise more than half of the world's population and this percentage is still dramatically increasing. The explosive urban growth over the next two decades poses long-term profound impact on people as well as the environment. Accurate and up-to-date delineation of urban settlements plays a fundamental role in defining planning strategies and in supporting sustainable development of urban settlements. In order to provide adequate data about urban extents and land covers, classifying satellite data has become a common practice, usually with accurate enough results. Indeed, a number of supervised learning methods have proven effective in urban area classification, but they usually depend on a large amount of training samples, whose collection is a time and labor expensive task. This issue becomes particularly serious when classifying large areas at the regional/global level. As an alternative to manual ground truth collection, in this work we use geo-referenced social media data. Cities and densely populated areas are an extremely fertile land for the production of individual geo-referenced data (such as GPS and social network data). Training samples derived from geo-referenced social media have several advantages: they are easy to collect, usually they are freely exploitable; and, finally, data from social media are spatially available in many locations, and with no doubt in most urban areas around the world. Despite these advantages, the selection of training samples from social media meets two challenges: 1) there are many duplicated points; 2) method is required to automatically label them as "urban/non-urban". The objective of this research is to validate automatic sample selection from geo-referenced social media and its applicability in one class classification for urban extent mapping from satellite images. The findings in this study shed new light on social media applications in the field of remote sensing.
Establishing a National 3d Geo-Data Model for Building Data Compliant to Citygml: Case of Turkey
NASA Astrophysics Data System (ADS)
Ates Aydar, S.; Stoter, J.; Ledoux, H.; Demir Ozbek, E.; Yomralioglu, T.
2016-06-01
This paper presents the generation of the 3D national building geo-data model of Turkey, which is compatible with the international OGC CityGML Encoding Standard. We prepare an ADE named CityGML-TRKBIS.BI that is produced by extending existing thematic modules of CityGML according to TRKBIS needs. All thematic data groups in TRKBIS geo-data model have been remodelled in order to generate the national large scale 3D geo-data model for Turkey. Specific attention has been paid to data groups that have different class structure according to related CityGML data themes such as building data model. Current 2D geo-information model for building data theme of Turkey (TRKBIS.BI) was established based on INSPIRE specifications for building (Core 2D and Extended 2D profiles), ISO/TC 211 standards and OGC web services. New version of TRKBIS.BI which is established according to semantic and geometric rules of CityGML will represent 2D-2.5D and 3D objects. After a short overview on generic approach, this paper describes extending CityGML building data theme according to TRKBIS.BI through several steps. First, building models of both standards were compared according to their data structure, classes and attributes. Second, CityGML building model was extended with respect to TRKBIS needs and CityGML-TRKBIS Building ADE was established in UML. This study provides new insights into 3D applications in Turkey. The generated 3D geo-data model for building thematic class will be used as a common exchange format that meets 2D, 2.5D and 3D implementation needs at national level.
NASA Astrophysics Data System (ADS)
Zittersteijn, M.; Vananti, A.; Schildknecht, T.; Dolado Perez, J. C.; Martinot, V.
2016-11-01
Currently several thousands of objects are being tracked in the MEO and GEO regions through optical means. The problem faced in this framework is that of Multiple Target Tracking (MTT). The MTT problem quickly becomes an NP-hard combinatorial optimization problem. This means that the effort required to solve the MTT problem increases exponentially with the number of tracked objects. In an attempt to find an approximate solution of sufficient quality, several Population-Based Meta-Heuristic (PBMH) algorithms are implemented and tested on simulated optical measurements. These first results show that one of the tested algorithms, namely the Elitist Genetic Algorithm (EGA), consistently displays the desired behavior of finding good approximate solutions before reaching the optimum. The results further suggest that the algorithm possesses a polynomial time complexity, as the computation times are consistent with a polynomial model. With the advent of improved sensors and a heightened interest in the problem of space debris, it is expected that the number of tracked objects will grow by an order of magnitude in the near future. This research aims to provide a method that can treat the association and orbit determination problems simultaneously, and is able to efficiently process large data sets with minimal manual intervention.
Simulation of how a geo-engineering intervention to restore arctic sea ice might work in practice
NASA Astrophysics Data System (ADS)
Jackson, L. S.; Crook, J. A.; Forster, P.; Jarvis, A.; Leedal, D.; Ridgwell, A. J.; Vaughan, N.
2013-12-01
The declining trend in annual minimum Arctic sea ice coverage and years of more pronounced drops like 2007 and 2012 raise the prospect of an Arctic Ocean largely free of sea ice in late summer and the potential for a climate crisis or emergency. In a novel computer simulation, we treated one realisation of a climate model (HadGEM2) as the real world and tried to restore its Arctic sea ice by the rapid deployment of geo-engineering with emission of SO2 into the Arctic stratosphere. The objective was to restore the annual minimum Arctic sea ice coverage to levels seen in the late twentieth century using as little geo-engineering as possible. We took intervention decisions as one might do in the real world: by committee, using a limited set of uncertain 'observations' from our simulated world and using models and control theory to plan the best intervention strategy for the coming year - so learning as we went and being thrown off course by future volcanoes and technological breakdowns. Uncertainties in real world observations were simulated by applying noise to emerging results from the climate model. Volcanic forcing of twenty-first century climate was included with the timing and magnitude of the simulated eruptions unknown by the 'geo-engineers' until after the year of the eruption. Monitoring of Arctic sea ice with the option to intervene with SO2 emissions started from 2018 and continued to 2075. Simulated SO2 emissions were made in January-May each year at a latitude of 79o N and an altitude within the range of contemporary tanker aircraft. The magnitude of emissions was chosen annually using a model predictive control process calibrated using results from CMIP5 models (excluding HadGEM2), using the simplified climate model MAGICC and assimilation of emerging annual results from the HadGEM2 'real world'. We found that doubts in the minds of the 'geo-engineers' of the effectiveness and the side effects of their past intervention, and the veracity of the models used for planning intervention were a constant feature of the simulation. As a result, their assumptions and intervention approaches were considerably revised as the simulation progressed. Side effects of the geo-engineering were difficult to explicitly determine without a control experiment. Nevertheless, we found wide spread changes in precipitation that were believed to be due to the geo-engineering - a later control experiment confirmed this belief. On termination of the SO2 geo-engineering, northern hemisphere temperatures rose sharply and Arctic sea ice area dropped dramatically. These termination effects were so large that attribution to the geo-engineering cessation was unambiguous.
Using GeoRSS feeds to distribute house renting and selling information based on Google map
NASA Astrophysics Data System (ADS)
Nong, Yu; Wang, Kun; Miao, Lei; Chen, Fei
2007-06-01
Geographically Encoded Objects RSS (GeoRSS) is a way to encode location in RSS feeds. RSS is a widely supported format for syndication of news and weblogs, and is extendable to publish any sort of itemized data. When Weblogs explode since RSS became new portals, Geo-tagged feed is necessary to show the location that story tells. Geographically Encoded Objects adopts the core of RSS framework, making itself the map annotations specified in the RSS XML format. The case studied illuminates that GeoRSS could be maximally concise in representation and conception, so it's simple to manipulate generation and then mashup GeoRSS feeds with Google Map through API to show the real estate information with other attribute in the information window. After subscribe to feeds of concerned subjects, users could easily check for new bulletin showing on map through syndication. The primary design goal of GeoRSS is to make spatial data creation as easy as regular Web content development. However, it does more for successfully bridging the gap between traditional GIS professionals and amateurs, Web map hackers, and numerous services that enable location-based content for its simplicity and effectiveness.
NASA Astrophysics Data System (ADS)
Skinner, Mark A.; Russell, Ray W.; Rudy, Richard J.; Gutierrez, David J.; Kim, Daryl L.; Crawford, Kirk; Gregory, Steve; Kelecy, Tom
2011-12-01
Optical surveys have identified a class of high area-to-mass ratio (HAMR) objects in the vicinity of the Geostationary Earth Orbit (GEO) ring [1]. The exact origin and nature of these objects are not well known, although their proximity to the GEO ring poses a hazard to active GEO satellites. Due to their high area-to-mass ratios, solar radiation pressure perturbs their orbits in ways that makes it difficult to predict their orbital trajectories over periods of time exceeding a week. To better understand these objects and their origins, observations that allow us to derive physical characteristics are required in order to improve the non-conservative force modeling for orbit determination and prediction. Information on their temperatures, areas, emissivities, and albedos may be obtained from thermal infrared, mid-wave infrared (MWIR), and visible measurements. Spectral features may help to identify the composition of the material, and thus possible origins for these objects. We have collected observational data on various HAMR objects from the AMOS observatory 3.6 m AEOS telescope. The thermal-IR spectra of these low-earth orbit objects acquired by the Broadband Array Spectrograph System (BASS) span wavelengths 3-13 μm and constitute a unique data set, providing a means of measuring, as a function of time, object fluxes. These, in turn, allow temperatures and emissivity-area products to be calculated. In some instances we have also collected simultaneous filtered visible photometric data on the observed objects. The multi-wavelength observations of the objects provide possible clues as to the nature of the observed objects. We describe briefly the nature and status of the instrumental programs used to acquire the data, our data of record, our data analysis techniques, and our current results, as well as future plans.
Visualisation Ability of Senior High School Students with Using GeoGebra and Transparent Mica
NASA Astrophysics Data System (ADS)
Thohirudin, M.; Maryati, TK; Dwirahayu, G.
2017-04-01
Visualisation ability is an ability to process, inform, and transform object which suitable for geometry topic in math. This research aims to describe the influence of using software GeoGebra and transparent mica for student’s visualisation ability. GeoGebra is shortness of geometry and algebra. GeoGebra is an open source program that is created for math. Transparent mica is a tool that is created by the author to transform a geometry object. This research is a quantitative experiment model. The subject of this research were students in grade XII of science program in Annajah Senior High School Rumpin with two classes which one as an experiment class (science one) and another one as a control class (science two). Experiment class use GeoGebra and transparent mica in the study, and control class use powerpoint in the study. Data of student’s visualisation ability is collected from posttest with visual questions which are gifted at the end of the research to both classes with topic “transformation geometry”. This research resulted that studying with GeoGebra and transparent mica had a better influence than studying with powerpoint to student’s visualisation ability. The time of study in class and the habit of the students to use software and tool affected the result of research. Although, GeoGebra and transparent mica can give help to students in transformation geometry topic.
Cloud-Based Distributed Control of Unmanned Systems
2015-04-01
during mission execution. At best, the data is saved onto hard-drives and is accessible only by the local team. Data history in a form available and...following open source technologies: GeoServer, OpenLayers, PostgreSQL , and PostGIS are chosen to implement the back-end database and server. A brief...geospatial map data. 3. PostgreSQL : An SQL-compliant object-relational database that easily scales to accommodate large amounts of data - upwards to
Analysis of Faint Glints from Stabilized GEO Satellites
2013-09-01
this regard temporal photometry (i.e., measurements of whole-object brightness as a function of time ) can be very valuable. For instance, GEO satellite ...INTRODUCTION Ground-based optical and radar sites routinely acquire resolved images of satellites , yielding a great deal of knowledge about orbiting...spacecraft. However, the important population of GEO satellites often cannot be resolved , and must be characterized using methods other than imagery. In
Simulation of Telescope Detectivity for Geo Survey and Tracking
NASA Astrophysics Data System (ADS)
Richard, P.
2014-09-01
As the number of space debris on Earths Orbit increases steadily, the need to survey, track and catalogue them becomes of key importance. In this context, CNES has been using the TAROT Telescopes (Rapid Telescopes for Transient Objects owned and operated by CNRS) for several years to conduct studies about space surveillance and tracking. Today, two testbeds of services using the TAROT telescopes are running every night: one for GEO situational awareness and the second for debris tracking. Additionally to the CNES research activity on space surveillance and tracking domain, an operational collision avoidance service for LEO and GEO satellites is in place at CNES for several years. This service named CAESAR (Conjunction Analysis and Evaluation: Alerts and Recommendations) is used by CNES as well as by external customers. As the optical debris tracking testbed based on TAROT telescopes is the first step toward an operational provider of GEO measures that could be used by CAESAR, simulations have been done to help choosing the sites and types of telescopes that could be added in the GEO survey and debris tracking telescope network. One of the distinctive characteristics of the optical observation of space debris compared to traditional astronomic observation is the need to observe objects at low elevations. The two mains reasons for this are the need to observe the GEO belt from non-equatorial sites and the need to observe debris at longitudes far from the telescope longitude. This paper presents the results of simulations of the detectivity for GEO debris of various telescopes and sites, based on models of the GEO belt, the atmosphere and the instruments. One of the conclusions is that clever detection of faint streaks and spread sources by image processing is one of the major keys to improve the detection of debris on the GEO belt.
Affordable Wide-field Optical Space Surveillance using sCMOS and GPUs
NASA Astrophysics Data System (ADS)
Zimmer, P.; McGraw, J.; Ackermann, M.
2016-09-01
Recent improvements in sCMOS technology allow for affordable, wide-field, and rapid cadence surveillance from LEO to out past GEO using largely off-the-shelf hardware. sCMOS sensors, until very recently, suffered from several shortcomings when compared to CCD sensors - lower sensitivity, smaller physical size and less predictable noise characteristics. Sensors that overcome the first two of these are now available commercially and the principals at J.T. McGraw and Associates (JTMA) have developed observing strategies that minimize the impact of the third, while leveraging the key features of sCMOS, fast readout and low average readout noise. JTMA has integrated a new generation sCMOS sensor into an existing COTS telescope system in order to develop and test new detection techniques designed for uncued optical surveillance across a wide range of apparent object angular rates - from degree per second scale of LEO objects to a few arcseconds per second for objects out past GEO. One further complication arises from this: increased useful frame rate means increased data volume. Fortunately, GPU technology continues to advance at a breakneck pace and we report on the results and performance of our new detection techniques implemented on new generation GPUs. Early results show significance within 20% of the expected theoretical limiting signal-to-noise using commodity GPUs in near real time across a wide range of object parameters, closing the gap in detectivity between moving objects and tracked objects.
Simultaneous Multi-Filter Optical Photometry of GEO Debris
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Cowardin, Heather; Barker, Edwin S.; Abercromby, Kira; Kelecy, Thomas
2011-01-01
Information on the physical characteristics of unresolved pieces of debris comes from an object's brightness, and how it changes with time and wavelength. True colors of tumbling, irregularly shaped objects can be accurately determined only if the intensity at all wavelengths is measured at the same time. In this paper we report on simultaneous photometric observations of objects at geosynchronous orbit (GEO) using two telescopes at Cerro Tololo Inter-American Observatory (CTIO). The CTIO/SMARTS 0.9-m observes in a Johnson B filter, while the 0.6-m MODEST (Michigan Orbital DEbris Survey Telescope) observes in a Cousins R filter. The two CCD cameras are electronically synchronized so that the exposure start time and duration are the same for both telescopes. Thus we obtain the brightness as a function of time in two passbands simultaneously, and can determine the true color of the object at any time. We will report here on such calibrated measurements made on a sample of GEO objects and what is the distribution of the observed B-R colors. In addition, using this data set, we will show what colors would be observed if the observations in different filters were obtained sequentially, as would be the case for conventional imaging observations with a single detector on a single telescope. Finally, we will compare our calibrated colors of GEO debris with colors determined in the laboratory of selected materials actually used in spacecraft construction.
Results of monitoring of the high orbits with ISON optical network
NASA Astrophysics Data System (ADS)
Molotov, Igor; Schildknecht, Thomas; Zalles, Rodolfo; Rumyantsev, Vasilij; Voropaev, Viktor; Zolotov, Vladimir; Kokina, Tatiana; Montojo, Francisco Javier; Namkhai, Tungalag
2016-07-01
International Scientific Optical Network (ISON) represents one of largest systems specializing in observation of space objects. ISON provides permanent monitoring of the whole GEO region, regular surveying of Molniya type orbits, and tracking of objects at GEO, GTO, HEO and LEO. ISON project is continuously developing and is joining now the 37 observation facilities in 15 countries with 79 telescopes of different class (aperture from 12.5 cm to 2.6 m). 15.4 millions measurements in 2.1 millions of tracklets for about 4100 objects are collected by KIAM in 2015. 339 new space objects have been discovered, 307 previously lost objects have been rediscovered. Telescopes of two European observatories (AIUB Zimmerwald and TFRM Barcelona) and two Latin American observatories (Bolivian Tarija and Mexican UAS Cosala) have joined to the ISON survey subsystem. New subsystem of 7 telescopes for extended GEO surveys is created (it allows KIAM to determine more precise GEO orbits for conjunction analysis). Also deployment of Roscosmos subsystem of six dedicated mini-observatories EOP-1/EOP-2 has been completed. ISON encompasses five groups of telescopes and three scheduling centers to better serve user's requests. Obtained measurements are processing at KIAM ballistic center to be used for scientific and applied goals, including collision risks analysis and space situation analysis. Achieved parameters of the above mentioned telescopes and plans of ISON network development will be presented and discussed.
GEO Collisional Risk Assessment Based on Analysis of NASA-WISE Data and Modeling
2015-10-18
GEO Collisional Risk Assessment Based on Analysis of NASA -WISE Data and Modeling Jeremy Murray Krezan1, Samantha Howard1, Phan D. Dao1, Derek...Surka2 1AFRL Space Vehicles Directorate,2Applied Technology Associates Incorporated From December 2009 through 2011 the NASA Wide-Field Infrared...of known debris. The NASA -WISE GEO belt debris population adds potentially thousands previously uncataloged objects. This paper describes
Geo-demographic analysis of fatal motorcycle crashes
DOT National Transportation Integrated Search
2001-01-01
The objective of this study is to analyze the combined motor vehicle crash data from the Fatality Analysis Reporting System (FARS) with the Claritas geo-demographic database from the lifestyle perspective to determine the appropriate media to use in ...
The Pulkovo Cooperation for Radar and Optical Observations of Space Objects
NASA Astrophysics Data System (ADS)
Molotov, I.; Konovalenko, A. A.; Tuccari, G.; Falkovich, I.; Nechaeva, M.; Kiladze, R.; Titenko, V.; Agapov, V.; Khutorovsky, Z. N.; Sukhov, P. P.; Burtsev, Yu.; Sochilina, A.; Abalakin, V.; et al.
The Pulkovo observatory is arranging the cooperation of optical and radio telescopes for space debris studies in two main research directions, i.e. the precise tracking of the GEO-objects for development of the dynamical control method and the barrier method study of small fragments produced by GEO-object explosions.Radar experiments are being carried out a few times per year by using the Evpatoria RT-70 transmitter and the receiving radio telescopes in Bear Lakes (Russia), Simeiz (Ukraine), Noto (Italy), and Urumqi (China). The data processing centers are located in N. Novgorod and Noto, and integrated into the Low Frequency VLBI Network (LFVN). The adjustment of the coordinated radar VLBI measurements has been completed, and the technique of beam-track searching has been tested. The program of the LFVN modernizations is in progress The Pulkovo cooperation of optical observers (PULCOO) includes observatories and observation stations of the former Soviet Union around the world, and is to provide the routine tracking of the GEO-objects. The adjustment has been carried out for the method to search for GEO-fragments in the barriers predicted on basis of the Pulkovo "LAPLACE" theory of motion. The refurbishment program for telescopes, which cooperate with the PULCOO, is in progress.
Sizing of "Mother Ship and Catcher" Missions for LEO Small Debris and for GEO Large Object Capture
NASA Technical Reports Server (NTRS)
Bacon, John B.
2009-01-01
Most LEO debris lies in a limited number of inclination "bands" associated with specific useful orbits. Objects in such narrow inclination bands have all possible Right Ascensions of Ascending Node (RAANs), creating a different orbit plane for nearly every piece of debris. However, a low-orbiting satellite will always phase in RAAN faster than debris objects in higher orbits at the same inclination, potentially solving the problem. Such a low-orbiting base can serve as a "mother ship" that can tend and then send small, disposable common individual catcher/deboost devices--one for each debris object--as the facility drifts into the same RAAN as each higher object. The dV necessary to catch highly-eccentric orbit debris in the center of the band alternatively allows the capture of less-eccentric debris in a wider inclination range around the center. It is demonstrated that most LEO hazardous debris can be removed from orbit in three years, using a single LEO launch of one mother ship--with its onboard magazine of freeflying low-tech catchers--into each of ten identified bands, with second or potentially third launches into only the three highest-inclination bands. The nearly 1000 objects near the geostationary orbit present special challenges in mass, maneuverability, and ultimate disposal options, leading to a dramatically different architecture and technology suite than the LEO solution. It is shown that the entire population of near-GEO derelict objects can be gathered and tethered together within a 3 year period for future scrap-yard operations using achievable technologies and only two earth launches.
Using GeoRePORT to report socio-economic potential for geothermal development
DOE Office of Scientific and Technical Information (OSTI.GOV)
Young, Katherine R.; Levine, Aaron
The Geothermal Resource Portfolio Optimization and Reporting Tool (GeoRePORT, http://en.openei.org/wiki/GeoRePORT) was developed for reporting resource grades and project readiness levels, providing the U.S. Department of Energy a consistent and comprehensible means of evaluating projects. The tool helps funding organizations (1) quantitatively identify barriers, (2) develop measureable goals, (3) objectively evaluate proposals, including contribution to goals, (4) monitor progress, and (5) report portfolio performance. GeoRePORT assesses three categories: geological, technical, and socio-economic. Here, we describe GeoRePORT, then focus on the socio-economic assessment and its applications for assessing deployment potential in the U.S. Socio-economic attributes include land access, permitting, transmission, and market.
Geostationary Coastal and Air Pollution Events (GEO-CAPE) Sensitivity Analysis Experiment
NASA Technical Reports Server (NTRS)
Lee, Meemong; Bowman, Kevin
2014-01-01
Geostationary Coastal and Air pollution Events (GEO-CAPE) is a NASA decadal survey mission to be designed to provide surface reflectance at high spectral, spatial, and temporal resolutions from a geostationary orbit necessary for studying regional-scale air quality issues and their impact on global atmospheric composition processes. GEO-CAPE's Atmospheric Science Questions explore the influence of both gases and particles on air quality, atmospheric composition, and climate. The objective of the GEO-CAPE Observing System Simulation Experiment (OSSE) is to analyze the sensitivity of ozone to the global and regional NOx emissions and improve the science impact of GEO-CAPE with respect to the global air quality. The GEO-CAPE OSSE team at Jet propulsion Laboratory has developed a comprehensive OSSE framework that can perform adjoint-sensitivity analysis for a wide range of observation scenarios and measurement qualities. This report discusses the OSSE framework and presents the sensitivity analysis results obtained from the GEO-CAPE OSSE framework for seven observation scenarios and three instrument systems.
NASA Technical Reports Server (NTRS)
Barker, Ed; Abercromby, Kira J.; Abell, Paul
2009-01-01
A key objective of NASA s Orbital Debris program office at Johnson Space Center (JSC) is to characterize the debris environment by way of assessing the physical properties (type, mass, density, and size) of objects in orbit. Knowledge of the geosynchronous orbit (GEO) debris environment in particular can be used to determine the hazard probability at specific GEO altitudes and aid predictions of the future environment. To calculate an optical size from an intensity measurement of an object in the GEO regime, a 0.175 albedo is assumed currently. However, identification of specific material type or types could improve albedo accuracy and yield a more accurate size estimate for the debris piece. Using spectroscopy, it is possible to determine the surface materials of space objects. The study described herein used the NASA Infrared Telescope Facility (IRTF) to record spectral data in the 0.6 to 2.5 micron regime on eight catalogued space objects. For comparison, all of the objects observed were in GEO or near-GEO. The eight objects consisted of two intact spacecraft, three rocket bodies, and three catalogued debris pieces. Two of the debris pieces stemmed from Titan 3C transtage breakup and the third is from COSMOS 2054. The reflectance spectra of the Titan 3C pieces share similar slopes (increasing with wavelength) and lack any strong absorption features. The COSMOS debris spectra is flat and has no absorption features. In contrast, the intact spacecraft show classic absorption features due to solar panels with a strong band gap feature near 1 micron. The two spacecraft are spin-stabilized objects and therefore have solar panels surrounding the outer surface. Two of the three rocket bodies are inertial upper stage (IUS) rocket bodies and have similar looking spectra. The slopes flatten out near 1.5 microns with absorption features in the near-infrared that are similar to that of white paint. The third rocket body has a similar flattening of slope but with fewer features of white paint - indicating that the surface paint on the SL-12 may be different than the IUS. This study shows that the surface materials of debris appear different spectrally than intact rocket bodies and spacecraft and therefore are not believed to be solar panel material or pristine white paint. Further investigation is necessary in order to eliminate materials as possible choices for the debris pieces.
NASA Astrophysics Data System (ADS)
Albercromby, Kira J.; Abell, Paul; Barker, Ed
2009-03-01
A key objective of NASA's Orbital Debris program office at Johnson Space Center (JSC) is to characterize the debris environment by way of assessing the physical properties (type, mass, density, and size) of objects in orbit. Knowledge of the geosynchronous orbit (GEO) debris environment in particular can be used to determine the hazard probability at specific GEO altitudes and aid predictions of the future environment. To calculate an optical size from an intensity measurement of an object in the GEO regime, a 0.175 albedo is assumed currently. However, identification of specific material type or types could improve albedo accuracy and yield a more accurate size estimate for the debris piece. Using spectroscopy, it is possible to determine the surface materials of space objects. The study described herein used the NASA Infrared Telescope Facility (IRTF) to record spectral data in the ~ 0.65 to 2.5 micron regime on eight catalogued space objects. For comparison, all of the objects observed were in GEO or near-GEO. The eight objects consisted of two intact spacecraft, three rocket bodies, and three catalogued debris pieces. Two of the debris pieces stemmed from Titan 3C transtage breakup and the third is from COSMOS 2054. The reflectance spectra of the Titan 3C pieces share similar slopes (increasing with wavelength) and lack any strong absorption features. The COSMOS debris spectrum has a slight slope and has no absorption features. In contrast, the intact spacecraft show classic absorption features due to solar cells with a strong band gap feature near 1 micron. The two spacecraft were spin-stabilized objects and therefore have solar panels surrounding the outer surface. Two of the three rocket bodies are inertial upper stage (IUS) rocket bodies and have similar looking spectra. The slopes flatten out near 1.5 microns with absorption features in the near-infrared that are similar to that of white paint. The third rocket body has a similar flattening of slope but with fewer features of white paint - indicating that the surface paint on the SL-12 may be different than the IUS. This study shows that the surface materials of debris appear different spectrally than intact rocket bodies and spacecraft and therefore are not believed to be solar cell material or pristine white paint. Further investigation is necessary in order to eliminate materials as possible choices for the debris pieces.
NCBI GEO: archive for functional genomics data sets--10 years on.
Barrett, Tanya; Troup, Dennis B; Wilhite, Stephen E; Ledoux, Pierre; Evangelista, Carlos; Kim, Irene F; Tomashevsky, Maxim; Marshall, Kimberly A; Phillippy, Katherine H; Sherman, Patti M; Muertter, Rolf N; Holko, Michelle; Ayanbule, Oluwabukunmi; Yefanov, Andrey; Soboleva, Alexandra
2011-01-01
A decade ago, the Gene Expression Omnibus (GEO) database was established at the National Center for Biotechnology Information (NCBI). The original objective of GEO was to serve as a public repository for high-throughput gene expression data generated mostly by microarray technology. However, the research community quickly applied microarrays to non-gene-expression studies, including examination of genome copy number variation and genome-wide profiling of DNA-binding proteins. Because the GEO database was designed with a flexible structure, it was possible to quickly adapt the repository to store these data types. More recently, as the microarray community switches to next-generation sequencing technologies, GEO has again adapted to host these data sets. Today, GEO stores over 20,000 microarray- and sequence-based functional genomics studies, and continues to handle the majority of direct high-throughput data submissions from the research community. Multiple mechanisms are provided to help users effectively search, browse, download and visualize the data at the level of individual genes or entire studies. This paper describes recent database enhancements, including new search and data representation tools, as well as a brief review of how the community uses GEO data. GEO is freely accessible at http://www.ncbi.nlm.nih.gov/geo/.
NASA Astrophysics Data System (ADS)
Hong, Liang
2013-10-01
The availability of high spatial resolution remote sensing data provides new opportunities for urban land-cover classification. More geometric details can be observed in the high resolution remote sensing image, Also Ground objects in the high resolution remote sensing image have displayed rich texture, structure, shape and hierarchical semantic characters. More landscape elements are represented by a small group of pixels. Recently years, the an object-based remote sensing analysis methodology is widely accepted and applied in high resolution remote sensing image processing. The classification method based on Geo-ontology and conditional random fields is presented in this paper. The proposed method is made up of four blocks: (1) the hierarchical ground objects semantic framework is constructed based on geoontology; (2) segmentation by mean-shift algorithm, which image objects are generated. And the mean-shift method is to get boundary preserved and spectrally homogeneous over-segmentation regions ;(3) the relations between the hierarchical ground objects semantic and over-segmentation regions are defined based on conditional random fields framework ;(4) the hierarchical classification results are obtained based on geo-ontology and conditional random fields. Finally, high-resolution remote sensed image data -GeoEye, is used to testify the performance of the presented method. And the experimental results have shown the superiority of this method to the eCognition method both on the effectively and accuracy, which implies it is suitable for the classification of high resolution remote sensing image.
Project GEOS-C. [designed to measure the topography of ocean surface and the sea state
NASA Technical Reports Server (NTRS)
1975-01-01
An oceanographic-geodetic satellite, designated Geodynamics Experimental Ocean Satellite-C (GEOS-C), an earth-orbiting spacecraft designed to measure precisely the topography of the ocean surface and the sea state (wave height, wave period, wave propagation direction) is described. Launch operations, spacecraft description, and mission objectives are included along with a brief flight history of the NASA satellite geodesy program. Principal investigations to be performed by the GEOS-C mission are discussed.
Geosynchronous Patrol Orbit for Space Situational Awareness
NASA Astrophysics Data System (ADS)
Thompson, B.; Kelecy, T.; Kubancik, T.; Flora, T.; Chylla, M.; Rose, D.
Applying eccentricity to a geosynchronous orbit produces both longitudinal and radial motion when viewed in Earth-fixed coordinates. An interesting family of orbits emerges, useful for “neighborhood patrol” space situational awareness and other missions. The basic result is a periodic (daily), quasielliptical, closed path around a fixed region of the geosynchronous (geo) orbit belt, keeping a sensor spacecraft in relatively close vicinity to designated geo objects. The motion is similar, in some regards, to the relative motion that may be encountered during spacecraft proximity operations, but on a much larger scale. The patrol orbit does not occupy a fixed slot in the geo belt, and the east-west motion can be combined with north-south motion caused by orbital inclination, leading to even greater versatility. Some practical uses of the geo patrol orbit include space surveillance (including catalog maintenance), and general space situational awareness. The patrol orbit offers improved, diverse observation geometry for angles-only sensors, resulting in faster, more accurate orbit determination compared to simple inclined geo orbits. In this paper, we analyze the requirements for putting a spacecraft in a patrol orbit, the unique station keeping requirements to compensate for perturbations, repositioning the patrol orbit to a different location along the geo belt, maneuvering into, around, and out of the volume for proximity operations with objects within the volume, and safe end-of-life disposal requirements.
Diagnostic Comparison of Meteorological Analyses during the 2002 Antarctic Winter
NASA Technical Reports Server (NTRS)
Manney, Gloria L.; Allen, Douglas R.; Kruger, Kirstin; Naujokat, Barbara; Santee, Michelle L.; Sabutis, Joseph L.; Pawson, Steven; Swinbank, Richard; Randall, Cora E.; Simmons, Adrian J.;
2005-01-01
Several meteorological datasets, including U.K. Met Office (MetO), European Centre for Medium-Range Weather Forecasts (ECMWF), National Centers for Environmental Prediction (NCEP), and NASA's Goddard Earth Observation System (GEOS-4) analyses, are being used in studies of the 2002 Southern Hemisphere (SH) stratospheric winter and Antarctic major warming. Diagnostics are compared to assess how these studies may be affected by the meteorological data used. While the overall structure and evolution of temperatures, winds, and wave diagnostics in the different analyses provide a consistent picture of the large-scale dynamics of the SH 2002 winter, several significant differences may affect detailed studies. The NCEP-NCAR reanalysis (REAN) and NCEP-Department of Energy (DOE) reanalysis-2 (REAN-2) datasets are not recommended for detailed studies, especially those related to polar processing, because of lower-stratospheric temperature biases that result in underestimates of polar processing potential, and because their winds and wave diagnostics show increasing differences from other analyses between similar to 30 and 10 hPa (their top level). Southern Hemisphere polar stratospheric temperatures in the ECMWF 40-Yr Re-analysis (ERA-40) show unrealistic vertical structure, so this long-term reanalysis is also unsuited for quantitative studies. The NCEP/Climate Prediction Center (CPC) objective analyses give an inferior representation of the upper-stratospheric vortex. Polar vortex transport barriers are similar in all analyses, but there is large variation in the amount, patterns, and timing of mixing, even among the operational assimilated datasets (ECMWF, MetO, and GEOS-4). The higher-resolution GEOS-4 and ECMWF assimilations provide significantly better representation of filamentation and small-scale structure than the other analyses, even when fields gridded at reduced resolution are studied. The choice of which analysis to use is most critical for detailed transport studies (including polar process modeling) and studies involving synoptic evolution in the upper stratosphere. The operational assimilated datasets are better suited for most applications than the NCEP/CPC objective analyses and the reanalysis datasets.
Predicting Good Features for Image Geo-Localization Using Per-Bundle VLAD (Open Access)
2016-02-18
transient scene elements (pedestrians, cars, billboards) and ubiquitous objects (trees, fences, signage ) can introduce obfuscating cues into the geo...windows, charac- teristic wall patterns, and letters on signage are detected as positive elements, while features from trees, people, car wheels
NASA Astrophysics Data System (ADS)
Glaves, Helen; Graham, Colin
2010-05-01
Geo-Seas - a pan-European infrastructure for the management of marine geological and geophysical data. Helen Glaves1 and Colin Graham2 on behalf of the Geo-Seas consortium The Geo-Seas project will create a network of twenty six European marine geoscience data centres from seventeen coastal countries including six from the Baltic Sea area. This will be achieved through the development of a pan-European infrastructure for the exchange of marine geoscientific data. Researchers will be able to locate and access harmonised and federated marine geological and geophysical datasets and data products held by the data centres through the Geo-Seas data portal, using a common data catalogue. The new infrastructure, an expansion of the exisiting SeaDataNet, will create an infrastructure covering oceanographic and marine geoscientific data. New data products and services will be developed following consultations with users on their current and future research requirements. Common data standards will be implemented across all of the data centres and other geological and geophysical organisations will be encouraged to adopt the protocols, standards and tools which are developed as part of the Geo-Seas project. Oceanographic and marine data include a wide range of variables, an important category of which are the geological and geophysical data sets. This data includes raw observational and analytical data as well as derived data products from seabed sediment samples, boreholes, geophysical surveys (seismic, gravity etc) and sidescan sonar surveys. All of which are essential in order to produce a complete interpretation of seabed geology. Despite there being a large volume of geological and geophysical data available for the marine environment it is currently very difficult to use these datasets in an integrated way between organisations due to different nomenclatures, formats, scales and coordinate systems being used within different organisations and also within different countries. This makes the direct use of primary data in an integrated way very difficult and also hampers use of the data sets in a harmonised way to produce multidisciplinary data products and services. To ensure interoperability with other marine environmental data types Geo-Seas ISO19115 metadata, OGC and GeoSciML standards will be used as the basis for the metadata profiles for the geological and geophysical data. This will be largely achieved by modifying the SeaDataNet metadata standard profile (Common Data Index or CDI), which is itself based upon the ISO19115 standard, to accommodate the requirements of the Geo-Seas project. The overall objective of Geo-Seas project is to build and deploy a unified marine geoscientific data infrastructure within Europe which will in effect provide a data grid for the sharing of marine geological and geophysical data. This will result in a major improvement in the locating, accessing and delivery of federated marine geological and geophysical data and data products from national geological surveys and research institutes across Europe. There is an emphasis on interoperability both with other disciplines as well as with other key framework projects including the European Marine Observation and Data Network (EMODNet) and One Geology - Europe. In addition, a key objective of the Geo-Seas project is to underpin European directives such as INSPIRE as well as recent framework programmes on both the global and European scale, for example Global Earth Observation System of Systems (GEOSS) and Global Monitoring for Environment and Security (GMES), all of which are intended to encourage the exchange of data and information. Geo-Seas consortium partners: NERC-BGS (United Kingdom), NERC-BODC (United Kingdom), NERC-NOCS (United Kingdom), MARIS (Netherlands), IFREMER (France), BRGM (France), TNO (Netherlands), BSH (Germany), IGME (Spain), INETI (Portugal), IGME (Greece), GSI (Ireland), BGR (Germany), OGS (Italy), GEUS (Denmark), NGU (Norway), PGI (Poland), EGK (Estonia), LIGG (Lithuania), IO-BAS (Bulgaria), NOA (Greece), CIRIA (United Kingdom), MUMM (Belgium), UB (Spain), UCC (Ireland), EU-Consult (Netherlands), CNRS (France), SHOM (France), CEFAS (United Kingdom), and LU (Latvia). The project is coordinated by British Geological Survey (BGS), while the technical coordination is performed by Marine Information Service (MARIS). The Geo-Seas project is an Integrated Infrastructure Initiative (I3) of the Research Infrastructures programme within EU FP7, contract number RI-238952. It has a duration of 42 months from 1st May 2009 till 31st October 2012. 1 British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK. e-mail: hmg@bgs.ac.uk 2 British Geological Survey, Murchison House, West Mains Road, Edinburgh, EH9 3LA, UK. e-mail: ccg@bgs.ac.uk
Pan-STARRRS Status and Geo Observations Results
2011-09-01
Earth Orbiting asteroids which may pose a threat. The final design includes four 1.8m telescopes each equipped with a giga- pixel camera and is...are relative to the rotation of the earth, the mount is commanded utilizing “stare mode” for all GEO observations. The belt is surveyed by...integration time the geo belt is observed M number of times. In order to detect an object it must be observed N number of times out of the possible M
GEO Population Estimates using Optical Survey Data
NASA Technical Reports Server (NTRS)
Barker, Edwin S.; Matney, Mark J.
2007-01-01
Optical survey data taken using the NASA Michigan Orbital Debris Survey Telescope (MODEST) gives us an opportunity to statistically sample faint object population in the Geosynchronous (GEO) and near-GEO environment. This paper will summarize the MODEST survey work that has been conducted by NASA since 2002, and will outline the techniques employed to arrive at the current population estimates in the GEO environment for dim objects difficult to detect and track using current systems in the Space Surveillance Network (SSN). Some types of orbits have a higher detection rate based on what parts of the GEO belt is being observed, a straightforward statistical technique is used to debias these observations to arrive at an estimate of the total population potentially visible to the telescope. The size and magnitude distributions of these fainter debris objects are markedly different from the catalogued population. GEO debris consists of at least two different populations, one which follows the standard breakup power law and one which has anomalously high Area-to-Mass Ratios (1 to approx. 30 square meters per kilogram; a sheet of paper = approx. 13 square meters per kilogram). The Inter-Agency Space Debris Coordination Committee (IADC) is investigating objects in GEO orbits with anomalously high Area-to-Mass Ratios (AMRs). The ESA Space Debris Telescope discovered this population and has and its properties of inclinations (0 to 30 degrees), changing eccentricities (0 and 0.6), and mean motions (approx. 1 rev), will be presented. The accepted interpretation of this orbital behavior is that solar radiation pressure drives the perturbations causing time varying inclinations and eccentricities. The orbital parameters are unstable for this population and thus difficult to predict. Their dim visual magnitudes and photometric variability make observations a challenge. The IADC has enlisted a series of observatories (participating institutions: University of Michigan/CTIO, Astronomical Institute University of Bern, Boeing LTS / AMOS, Keldysh Institute of Applied Mathematics) at different longitudes. Complete observational coverage over periods of days to months will provide a better understanding of the properties, such as solar radiation pressure effects on orbital elements, size, shape, attitude, color variations, and spectral characteristics. Results from recent observational programs will be summarized, and includes a description of the orbit elements prediction processes, a summary of the metric tracking performance, and some photometric characteristics of this class of debris.
NCBI GEO: archive for functional genomics data sets—10 years on
Barrett, Tanya; Troup, Dennis B.; Wilhite, Stephen E.; Ledoux, Pierre; Evangelista, Carlos; Kim, Irene F.; Tomashevsky, Maxim; Marshall, Kimberly A.; Phillippy, Katherine H.; Sherman, Patti M.; Muertter, Rolf N.; Holko, Michelle; Ayanbule, Oluwabukunmi; Yefanov, Andrey; Soboleva, Alexandra
2011-01-01
A decade ago, the Gene Expression Omnibus (GEO) database was established at the National Center for Biotechnology Information (NCBI). The original objective of GEO was to serve as a public repository for high-throughput gene expression data generated mostly by microarray technology. However, the research community quickly applied microarrays to non-gene-expression studies, including examination of genome copy number variation and genome-wide profiling of DNA-binding proteins. Because the GEO database was designed with a flexible structure, it was possible to quickly adapt the repository to store these data types. More recently, as the microarray community switches to next-generation sequencing technologies, GEO has again adapted to host these data sets. Today, GEO stores over 20 000 microarray- and sequence-based functional genomics studies, and continues to handle the majority of direct high-throughput data submissions from the research community. Multiple mechanisms are provided to help users effectively search, browse, download and visualize the data at the level of individual genes or entire studies. This paper describes recent database enhancements, including new search and data representation tools, as well as a brief review of how the community uses GEO data. GEO is freely accessible at http://www.ncbi.nlm.nih.gov/geo/. PMID:21097893
Geostationary Coastal and Air Pollution Events (GEO CAPE) Instrument Performance Study
NASA Technical Reports Server (NTRS)
Mannino, Antonio; Hartman, Kathy R.
2014-01-01
The Ultimate objective of the GEO-CAPE 2014 study: Quantify the cost impact of very specific changes in instrument performance! The customer has defined 4 instrument types they are notionally interested in:! FR: Filter Radiometer! WAS: Wide Angle Spectrometer! MSS: Multi Slit Spectrometer! SSS: Single Slit Spectrometer.
Impact of End-of-Life manoeuvres on the collision risk in protected regions
NASA Astrophysics Data System (ADS)
Frey, Stefan; Lemmens, Stijn; Bastida Virgili, Benjamin; Flohrer, Tim; Gass, Volker
2017-09-01
The Inter-Agency Space Debris Coordination Committee (IADC) Space Debris Mitigation Guidelines, issued in 2002 and revised in 2007, address the post mission disposal of objects in orbit. After their mission, objects crossing the Low Earth Orbit (LEO) should have a remaining lifetime in orbit not exceeding 25 years. Objects near the Geostationary Orbit (GEO) region should be placed in an orbit that remains outside of the GEO protected region. In this paper, the impact of satellites and rocket bodies performing End-of-Life (EOL) orbital manoeuvres on the collision risk in the LEO and GEO protected regions is investigated. The cases of full or partial compliance with the IADC post mission disposal guideline are studied. ESA's Meteoroid and Space Debris Terrestrial Environment Reference (MASTER) model is used to compare the space debris flux rate of the object during the remaining lifetime estimated for the pre-EOL-manoeuvre and for the post-EOL-manoeuvre orbit. The study shows that, on average, the probability of collision can be significantly decreased by performing an EOL-manoeuver.
Oniki, Yusuke; Koumo, Hideo; Iwazaki, Yoshitaka; Ueno, Tomo
2010-06-15
The relation between germanium monoxide (GeO) desorption and either improvement or deterioration in electrical characteristics of metalGeO(2)Ge capacitors fabricated by thermal oxidation has been investigated. In the metalGeO(2)Ge stack, two processes of GeO desorption at different sites and at different temperatures were observed by thermal desorption spectroscopy measurements. The electrical characteristics of as-oxidized metalGeO(2)Ge capacitors shows a large flat-band voltage shift and minority carrier generation due to the GeO desorption from the GeO(2)Ge interface during oxidation of Ge substrates. On the other hand, the electrical properties were drastically improved by a postmetallization annealing at low temperature resulting in a metal catalyzed GeO desorption from the top interface.
First ISON observations for satellite conjunction analysis in the Western Hemisphere
NASA Astrophysics Data System (ADS)
Zalles, R.; Molotov, I.; Kokina, T.; Zolotov, V.; Condori, R.
2018-01-01
In this paper we report on observations of a pair of approaching space objects in the beginning of June 2016, observed jointly by the Tarija Observatory in Bolivia and the Mexican observatory of Sinaloa University in Cosala in the context of the ISON collaboration. These objects were the STAR ONE C1 (2007-056A) active satellite in GEO position 65\\ deg west, and the passive satellite LES 6 (1968-081D). The large number of measurements obtained in a few nights allowed a precise orbit reconstruction. The passive satellite LES 6 (with a brigtness amplitude variation of 3 magnitudes) was too faint for the small aperture of the Cosala telescope.
Observation of GEO Satellite Above Thailand’s Sky
NASA Astrophysics Data System (ADS)
Kasonsuwan, K.; Wannawichian, S.; Kirdkao, T.
2017-09-01
The direct observations of Geostationary Orbit (GEO) satellites above Thailand’s sky by 0.7-meters telescope were proceeded at Inthanon Mt., Chiang Mai, Thailand. The observation took place at night with Sidereal Stare Mode (SSM). With this observing mode, the moving object will appear as a streak. The star identification for image calibration is based on (1) a star catalogue, (2) the streak detection of the satellite using the software and (3) the extraction of the celestial coordinate of the satellite as a predicted position. Finally, the orbital elements for GEO satellites were calculated.
Oniki, Yusuke; Koumo, Hideo; Iwazaki, Yoshitaka; Ueno, Tomo
2010-01-01
The relation between germanium monoxide (GeO) desorption and either improvement or deterioration in electrical characteristics of metal∕GeO2∕Ge capacitors fabricated by thermal oxidation has been investigated. In the metal∕GeO2∕Ge stack, two processes of GeO desorption at different sites and at different temperatures were observed by thermal desorption spectroscopy measurements. The electrical characteristics of as-oxidized metal∕GeO2∕Ge capacitors shows a large flat-band voltage shift and minority carrier generation due to the GeO desorption from the GeO2∕Ge interface during oxidation of Ge substrates. On the other hand, the electrical properties were drastically improved by a postmetallization annealing at low temperature resulting in a metal catalyzed GeO desorption from the top interface. PMID:20644659
Mobile device geo-localization and object visualization in sensor networks
NASA Astrophysics Data System (ADS)
Lemaire, Simon; Bodensteiner, Christoph; Arens, Michael
2014-10-01
In this paper we present a method to visualize geo-referenced objects on modern smartphones using a multi- functional application design. The application applies different localization and visualization methods including the smartphone camera image. The presented application copes well with different scenarios. A generic application work flow and augmented reality visualization techniques are described. The feasibility of the approach is experimentally validated using an online desktop selection application in a network with a modern of-the-shelf smartphone. Applications are widespread and include for instance crisis and disaster management or military applications.
Optical Studies of Space Debris at GEO: Survey and Follow-up with Two Telescopes
NASA Technical Reports Server (NTRS)
Seitzer, P.; Abercomby, K. J.; Rodriquez, H. M.; Barker, E. S.
2007-01-01
For 14 nights in March 2007, we used two telescopes at the Cerro Tololo Inter-American Observatory (CTIO) in Chile to study the nature of space debris at Geosynchronous Earth Orbit (GEO). In this project one telescope was dedicated to survey operations, while a second telescope was used for follow-up observations for orbits and colors. The goal was to obtain orbital and photometric information on every faint object found with the survey telescope. Thus we concentrate on objects fainter than R = 15th magnitude.
Optical Observations of GEO Debris with Two Telescopes
NASA Technical Reports Server (NTRS)
Seitzer, P.; Abercromby, K.; Rodriguez, H.; Barker, E.
2007-01-01
For several years, the Michigan Orbital DEbris Survey Telescope (MODEST), the University of Michigan s 0.6/0.9-m Schmidt telescope on Cerro Tololo Inter-American Observatory in Chile has been used to survey the debris population at GEO in the visible regime. Magnitudes, positions, and angular rates are determined for GEO objects as they move across the telescope s field-of-view (FOV) during a 5-minute window. This short window of time is not long enough to determine a full six parameter orbit so usually a circular orbit is assumed. A longer arc of time is necessary to determine eccentricity and to look for changes in the orbit with time. MODEST can follow objects in real-time, but only at the price of stopping survey operations. A second telescope would allow for longer arcs of orbit to obtain the full six orbital parameters, as well as assess the changes over time. An additional benefit of having a second telescope is the capability of obtaining BVRI colors of the faint targets, aiding efforts to determine the material type of faint debris. For 14 nights in March 2007, two telescopes were used simultaneously to observe the GEO debris field. MODEST was used exclusively in survey mode. As objects were detected, they were handed off in near real-time to the Cerro Tololo 0.9-m telescope for follow-up observations. The goal was to determine orbits and colors for all objects fainter than R = 15th magnitude (corresponds to 1 meter in size assuming a 0.2 albedo) detected by MODEST. The hand-off process was completely functional during the final eight nights and follow-ups for objects from night-to-night were possible. The cutoff magnitude level of 15th was selected on the basis of an abrupt change in the observed angular rate distribution in the MODEST surveys. Objects brighter than 15th magnitude tend to lie on a well defined locus in the angular rate plane (and have orbits in the catalog), while fainter objects fill the plane almost uniformly. We need to determine full six-parameter orbits to investigate what causes this change in observed angular rates. Are these faint objects either the same population of high area-to-mass (A/M) objects on eccentric orbits as discovered by the ESA Space Debris Telescope (Schildknecht, et al. 2004), or are they just normal debris from breakups in GEO?
NASA Technical Reports Server (NTRS)
Peuquet, D. J.
1986-01-01
A growing need to usse geographic information systems (GIS) to improve the flexibility and overall performance of very large, heterogeneous data bases was examined. The Vaster structure and the Topological Grid structure were compared to test whether such hybrid structures represent an improvement in performance. The use of artificial intelligence in a geographic/earth sciences data base context is being explored. The architecture of the Knowledge Based GIS (KBGIS) has a dual object/spatial data base and a three tier hierarchial search subsystem. Quadtree Spatial Spectra (QTSS) are derived, based on the quadtree data structure, to generate and represent spatial distribution information for large volumes of spatial data.
Geo3DML: A standard-based exchange format for 3D geological models
NASA Astrophysics Data System (ADS)
Wang, Zhangang; Qu, Honggang; Wu, Zixing; Wang, Xianghong
2018-01-01
A geological model (geomodel) in three-dimensional (3D) space is a digital representation of the Earth's subsurface, recognized by geologists and stored in resultant geological data (geodata). The increasing demand for data management and interoperable applications of geomodelscan be addressed by developing standard-based exchange formats for the representation of not only a single geological object, but also holistic geomodels. However, current standards such as GeoSciML cannot incorporate all the geomodel-related information. This paper presents Geo3DML for the exchange of 3D geomodels based on the existing Open Geospatial Consortium (OGC) standards. Geo3DML is based on a unified and formal representation of structural models, attribute models and hierarchical structures of interpreted resultant geodata in different dimensional views, including drills, cross-sections/geomaps and 3D models, which is compatible with the conceptual model of GeoSciML. Geo3DML aims to encode all geomodel-related information integrally in one framework, including the semantic and geometric information of geoobjects and their relationships, as well as visual information. At present, Geo3DML and some supporting tools have been released as a data-exchange standard by the China Geological Survey (CGS).
Active space debris charging for contactless electrostatic disposal maneuvers
NASA Astrophysics Data System (ADS)
Schaub, Hanspeter; Sternovsky, Zoltán
2014-01-01
The remote charging of a passive object using an electron beam enables touchless re-orbiting of large space debris from geosynchronous orbit (GEO) using electrostatic forces. The advantage of this method is that it can operate with a separation distance of multiple craft radii, thus reducing the risk of collision. The charging of the tug-debris system to high potentials is achieved by active charge transfer using a directed electron beam. Optimal potential distributions using isolated- and coupled-sphere models are discussed. A simple charging model takes into account the primary electron beam current, ultra-violet radiation induced photoelectron emission, collection of plasma particles, secondary electron emission and the recapture of emitted particles. The results show that through active charging in a GEO space environment high potentials can be both achieved and maintained with about a 75% transfer efficiency. Further, the maximum electrostatic tractor force is shown to be insensitive to beam current levels. This latter later result is important when considering debris with unknown properties.
Joshi, Ashish; de Araujo Novaes, Magdala; Machiavelli, Josiane; Iyengar, Sriram; Vogler, Robert; Johnson, Craig; Zhang, Jiajie; Hsu, Chiehwen E
2012-01-01
Public health data is typically organized by geospatial units. Routine geographic monitoring of health data enables an understanding of the spatial patterns of events in terms of causes and controls. GeoVisualization (GeoVis) allows users to see information hidden both visually and explicitly on a map. Despite the applicability of GeoVis in public health, it is still underused for visualizing public health data. The objective of this study is to examine the perception of telehealth users' to utilize GeoVis as a proof of concept to facilitate visual exploration of telehealth data in Brazil using principles of human centered approach and cognitive fit theory. A mixed methods approach combining qualitative and quantitative assessments was utilized in this cross sectional study conducted at the Telehealth Center of the Federal University of Pernambuco (NUTE-UFPE), Recife, Brazil. A convenient sample of 20 participants currently involved in NUTES was drawn during a period of Sep-Oct 2011. Data was gathered using previously tested questionnaire surveys and in-person interviews. Socio-demographic Information such as age, gender, prior education, familiarity with the use of computer and GeoVis was gathered. Other information gathered included participants' prior spatial analysis skills, level of motivation and use of GeoVis in telehealth. Audio recording was done for all interviews conducted in both English and Portuguese, and transcription of the audio content to English was done by a certified translator. Univariate analysis was performed and means and standard deviations were reported for the continuous variables and frequency distributions for the categorical variables. For the open-ended questions, we utilized a grounded theory to identify themes and their relationship as they emerge from the data. Analysis of the quantitative data was performed using SAS V9.1 and qualitative data was performed using NVivo9. The average age of participants was 28 years (SD=7), a majority of them were females and 100% were professionals with graduate degrees. The users had diverse backgrounds including nursing, computer science, biomedical informatics, statistics, dentistry, administration and engineering. The users had varied roles and responsibilities, used computers frequently but only 5% of them were familiar with GeoVis. Google maps were the most common GeoVis application that the users were familiar with. Despite having minimal spatial skills, there was a strong motivation and relevance among the telehealth users to use GeoVis to facilitate visual exploration of telehealth data for better informed decision making. Results also showed that of the 60% participants with no GeoVis familiarity; 33% had moderate to large data exploratory role, 83% had no spatial skills but 58% preferred analyzing both spatial and temporal dimensions of the data. Majority of the participants agreed to have maps as the first choice to represent the data as it will be able to display the events both in place and time. The results demonstrate a potentially growing need for the use of GeoVis applications to evaluate telehealth data. Understanding of user needs is essential to ensure that the technology is appropriately functional and will be useful to complete the tasks.
NASA Astrophysics Data System (ADS)
Durden, D.; Muraoka, H.; Scholes, R. J.; Kim, D. G.; Loescher, H. W.; Bombelli, A.
2017-12-01
The development of an integrated global carbon cycle observation system to monitor changes in the carbon cycle, and ultimately the climate system, across the globe is of crucial importance in the 21stcentury. This system should be comprised of space and ground-based observations, in concert with modelling and analysis, to produce more robust budgets of carbon and other greenhouse gases (GHGs). A global initiative, the GEO Carbon and GHG Initiative, is working within the framework of Group on Earth Observations (GEO) to promote interoperability and provide integration across different parts of the system, particularly at domain interfaces. Thus, optimizing the efforts of existing networks and initiatives to reduce uncertainties in budgets of carbon and other GHGs. This is a very ambitious undertaking; therefore, the initiative is separated into tasks to provide actionable objectives. Task 3 focuses on the optimization of in-situ observational networks. The main objective of Task 3 is to develop and implement a procedure for enhancing and refining the observation system for identified essential carbon cycle variables (ECVs) that meets user-defined specifications at minimum total cost. This work focuses on the outline of the implementation plan, which includes a review of essential carbon cycle variables and observation technologies, mapping the ECVs performance, and analyzing gaps and opportunities in order to design an improved observing system. A description of the gap analysis of in-situ observations that will begin in the terrestrial domain to address issues of missing coordination and large spatial gaps, then extend to ocean and atmospheric observations in the future, will be outlined as the subsequent step to landscape mapping of existing observational networks.
Scalable persistent identifier systems for dynamic datasets
NASA Astrophysics Data System (ADS)
Golodoniuc, P.; Cox, S. J. D.; Klump, J. F.
2016-12-01
Reliable and persistent identification of objects, whether tangible or not, is essential in information management. Many Internet-based systems have been developed to identify digital data objects, e.g., PURL, LSID, Handle, ARK. These were largely designed for identification of static digital objects. The amount of data made available online has grown exponentially over the last two decades and fine-grained identification of dynamically generated data objects within large datasets using conventional systems (e.g., PURL) has become impractical. We have compared capabilities of various technological solutions to enable resolvability of data objects in dynamic datasets, and developed a dataset-centric approach to resolution of identifiers. This is particularly important in Semantic Linked Data environments where dynamic frequently changing data is delivered live via web services, so registration of individual data objects to obtain identifiers is impractical. We use identifier patterns and pattern hierarchies for identification of data objects, which allows relationships between identifiers to be expressed, and also provides means for resolving a single identifier into multiple forms (i.e. views or representations of an object). The latter can be implemented through (a) HTTP content negotiation, or (b) use of URI querystring parameters. The pattern and hierarchy approach has been implemented in the Linked Data API supporting the United Nations Spatial Data Infrastructure (UNSDI) initiative and later in the implementation of geoscientific data delivery for the Capricorn Distal Footprints project using International Geo Sample Numbers (IGSN). This enables flexible resolution of multi-view persistent identifiers and provides a scalable solution for large heterogeneous datasets.
Gomes, J F P; Radovanovic, M
2008-05-01
Fires of large dimension destroy forests, harvests and housing objects. Apart from that combustion products and burned surfaces become large ecological problems. Very often fires emerge simultaneously on different locations of a region so a question could be asked if they always have been a consequence of negligence, pyromania, high temperatures or maybe there has been some other cause. This paper is an attempt of establishing the possible connection between forest fires that numerous satellites registered and activities happening on the Sun immediately before fires ignite. Fires emerged on relatively large areas from Portugal and Spain on August 2005, as well as on other regions of Europe. The cases that have been analyzed show that, in every concrete situation, an emission of strong electromagnetic and thermal corpuscular energy from highly energetic regions that were in geo-effective position had preceded the fires. Such emissions have, usually, very high energy and high speeds of particles and come from coronary holes that also have been either in the very structure or in the immediate closeness of the geo-effective position. It should also be noted that the solar wind directed towards the Earth becomes weaker with deeper penetration towards the topographic surface. However, the results presented in this paper suggest that, there is a strong causality relationship between solar activity and the ignition of these forest fires taking place in South-western Europe.
Teaching Introductory Mineralogy With the GeoWall
NASA Astrophysics Data System (ADS)
Anderson, C. D.; Haymon, R. M.
2003-12-01
Mineralogy, like many topics in Earth Sciences, contains inherently three-dimensional topics that are difficult to teach. Concepts such as crystal symmetry and forms, Miller indices, the polymerization of silica tetrahedra and resulting structures of silicate mineral groups, and the interaction of light and minerals are particularly difficult. Two-dimensional diagrams are limited in their effectiveness, and physical models, while effective, are expensive and do not work as well in large class settings. The GeoWall system brings the effectiveness of physical models to the large classroom. In Fall 2003, we will integrate the GeoWall into our introductory mineralogy classes at UCSB using a combination of commercial software, atomic structure models available on the web, and custom content created in-house. The commercial software SHAPE (www.shapesoftware.com) allows users to build and display crystal shapes and their symmetry. Though not designed for the GeoWall, the software's stereopair display mode works perfectly on the system. Using the Chime web browser plug-in (www.mdl.com), computer models of silicate minerals available from the Virtual Museum of Minerals and Molecules (www.soils.umn.eduvirtual_museum) provide an interactive display of silicate mineral structure that illustrates the tetrahedral framework. Again, while not developed for the GeoWall, the Chime plug-in works seamlessly with the GeoWall hardware. 3-D GeoWall images that display light paths through minerals, and reveal relationships between crystal symmetry and optical indicatrix properties, have been developed in-house using a combination of SHAPE and 3D modeling software. The 3-D GeoWall images should convey in an instant these difficult concepts that students historically have struggled to visualize. Initial assessment of the GeoWall's effectiveness as a mineralogy teaching aid at UCSB in Fall 2003 will come from the instructor's impressions and by comparing test scores with classes from previous years.
NASA Astrophysics Data System (ADS)
Aleksandrova, A. G.; Bordovitsyna, T. V.; Chuvashov, I. N.
2011-07-01
In the present work results of investigations of the effect of radiation pressure on the orbital evolution of objects in the GEO are presentеd.. MEGNO-analysis of orbits in the GEO for different values of sail (area to mass ratio) have been performed. Average parameter MEGNO as main indicator of chaotic or stable motion has been used. The results have been obtained using software package "Numerical model of the systems artificial satellite motion", implemented on the cluster "Skiff Cyberia".
Design, Implementation and Applications of 3d Web-Services in DB4GEO
NASA Astrophysics Data System (ADS)
Breunig, M.; Kuper, P. V.; Dittrich, A.; Wild, P.; Butwilowski, E.; Al-Doori, M.
2013-09-01
The object-oriented database architecture DB4GeO was originally designed to support sub-surface applications in the geo-sciences. This is reflected in DB4GeO's geometric data model as well as in its import and export functions. Initially, these functions were designed for communication with 3D geological modeling and visualization tools such as GOCAD or MeshLab. However, it soon became clear that DB4GeO was suitable for a much wider range of applications. Therefore it is natural to move away from a standalone solution and to open the access to DB4GeO data by standardized OGC web-services. Though REST and OGC services seem incompatible at first sight, the implementation in DB4GeO shows that OGC-based implementation of web-services may use parts of the DB4GeO-REST implementation. Starting with initial solutions in the history of DB4GeO, this paper will introduce the design, adaptation (i.e. model transformation), and first steps in the implementation of OGC Web Feature (WFS) and Web Processing Services (WPS), as new interfaces to DB4GeO data and operations. Among its capabilities, DB4GeO can provide data in different data formats like GML, GOCAD, or DB3D XML through a WFS, as well as its ability to run operations like a 3D-to-2D service, or mesh-simplification (Progressive Meshes) through a WPS. We then demonstrate, an Android-based mobile 3D augmented reality viewer for DB4GeO that uses the Web Feature Service to visualize 3D geo-database query results. Finally, we explore future research work considering DB4GeO in the framework of the research group "Computer-Aided Collaborative Subway Track Planning in Multi-Scale 3D City and Building Models".
A mission to preserve the geostationary region
NASA Astrophysics Data System (ADS)
Smith, D. A.; Martin, C.; Kassebom, M.; Petersen, H.; Shaw, A.; Skidmore, B.; Smith, D.; Stokes, H.; Willig, A.
2004-01-01
The RObotic Geostationary orbit Restorer, ROGER, is a programme aimed at reducing the risk to satellite operations posed by the existence of failed and spent satellites and other categories of space debris. To achieve this, the concept of mass removal by an intervention mission is considered for the GEO region. This paper describes the results of studies into the level of risk posed at present and in the near future to GEO assets. It also investigates practical means for re-orbiting objects that can no longer be manoeuvred away from the operational GEO region by ground command.
GEO-MOTION: A fresh approach to land, water and sea level changes in a European habitat
NASA Astrophysics Data System (ADS)
Cloetingh, S.; Geo-Motion Consortium, T.; GEO-MOTION Consortium
2003-04-01
The present state and behaviour of the Shallow Earth System is a consequence of processes on a wide range of time scales. These include the long term tectonic effects on uplift, subsidence and river systems, residual effects of the ice ages on crustal movement and geochemistry, natural climate to environmental changes over recent millennia and up to the present, and the powerful anthropogenic impacts of the last century. If we are to understand the present state of the system, to predict its future and to engineer our use of it, this spectrum of processes, operating concurrently but on different time scales, needs to be better understood. The challenge to the Geosciences is to describe the state of the system, to monitor its changes, to forecast its evolution and, in collaboration with others, to evaluate modes of sustainable use by human society. Land, water and sea level changes can seriously affect the sustainability of ecological and human habitats in Europe. When sea water or surface water levels rise, or land subsides, the risk of flooding increases, directly inflicting on local ecosystems and human habitats. The effects on society are widely known as many of the affected areas in Europe are densely populated and the financial loss foreseen is tremendous. On the other hand, declining water levels and uplift may lead to a higher risk of desertification. These changes are caused by both natural processes and human activities, but the absolute and relative contributions of each of these processes are still little understood. Only very recently, the impact of processes located in the underlying subsurface of intraplate areas has been recognized in the coastal realm, leading to the newly coined term ‘Environmental Earth System Dynamics’. The members of the Geo-Motion consortium have joined forces in order to create a fully integrated pan-European research infrastructure (a virtual scientific centre) on a hitherto not existing scale. It runs monitoring programs including satellite, surface and borehole monitoring instruments. It integrates large scale and excellent geo-mechanical, geo-chemical and geo-biological laboratory facilities. Based on existing structures and data sets it develops a new geo data infrastructure containing historical data on global and regional changes in combination with the vulnerability of natural and human habitats. Most significant milestones are a large scale and excellent know-how base on geo-motion modelling and simulation, as well as on risk and impact assessment. The development of a foresight and assessment competency represents a long-term strategic scientific objective for the consortium. It is vital that it is also promoted in education, which will be done through the development of a European School for Predictive Geoscience, in which parallel masters programmes will be offered by the university partners based on their pooled expertise. The national geoscience surveys play a key role in delivering the outputs of research into the public, policy and industrial domains.
GEO light imaging national testbed (GLINT) heliostat design and testing status
NASA Astrophysics Data System (ADS)
Thornton, Marcia A.; Oldenettel, Jerry R.; Hult, Dane W.; Koski, Katrina; Depue, Tracy; Cuellar, Edward L.; Balfour, Jim; Roof, Morey; Yarger, Fred W.; Newlin, Greg; Ramzel, Lee; Buchanan, Peter; Mariam, Fesseha G.; Scotese, Lee
2002-01-01
The GEO Light Imaging National Testbed (GLINT) will use three laser beams producing simultaneous interference fringes to illuminate satellites in geosynchronous earth orbit (GEO). The reflected returns will be recorded using a large 4,000 m2 'light bucket' receiver. This imaging methodology is termed Fourier Telescopy. A major component of the 'light bucket' will be an array of 40 - 80 heliostats. Each heliostat will have a mirrored surface area of 100 m2 mounted on a rigid truss structure which is supported by an A-frame. The truss structure attaches to the torque tube elevation drive and the A-frame structure rests on an azimuth ring that could provide nearly full coverage of the sky. The heliostat is designed to operate in 15 mph winds with jitter of less than 500 microradians peak-to- peak. One objective of the design was to minimize receiver cost to the maximum extent possible while maintaining GLINT system performance specifications. The mechanical structure weights approximately seven tons and is a simple fabricated steel framework. A prototype heliostat has been assembled at Stallion Range Center, White Sands Missile Range, New Mexico and is being tested under a variety of weather and operational conditions. The preliminary results of that testing will be presented as well as some finite element model analyses that were performed to predict the performance of the structure.
Detection and Dynamic Analysis of Space Debris in the Geo Ring
NASA Astrophysics Data System (ADS)
Lacruz, E.; Abad, C.; Downes, J. J.; Casanova, D.; Tresaco, E.
2018-01-01
There are different populations of space debris (SD) in the geostationary (GEO) region. It is of great interest to know their dynamics, in order to contribute to aspects such as alerts against possible collisions, repositioning of GEO satellites or placing those satellites that come into service. In this contribution we present a study about the detection and dynamic analysis of SD located in the GEO ring. Using the telescopes of the Venezuelan Obseratory National (VON), a large amount of astrometric observations have been acquired. A preliminary dynamic analysis of them has been carried out, which evidences the average relative motion of these orbiters with a mean absolute error for coordinates of ≍ 0.09 pix.
NASA Astrophysics Data System (ADS)
Long, M. S.; Yantosca, R.; Nielsen, J.; Linford, J. C.; Keller, C. A.; Payer Sulprizio, M.; Jacob, D. J.
2014-12-01
The GEOS-Chem global chemical transport model (CTM), used by a large atmospheric chemistry research community, has been reengineered to serve as a platform for a range of computational atmospheric chemistry science foci and applications. Development included modularization for coupling to general circulation and Earth system models (ESMs) and the adoption of co-processor capable atmospheric chemistry solvers. This was done using an Earth System Modeling Framework (ESMF) interface that operates independently of GEOS-Chem scientific code to permit seamless transition from the GEOS-Chem stand-alone serial CTM to deployment as a coupled ESM module. In this manner, the continual stream of updates contributed by the CTM user community is automatically available for broader applications, which remain state-of-science and directly referenceable to the latest version of the standard GEOS-Chem CTM. These developments are now available as part of the standard version of the GEOS-Chem CTM. The system has been implemented as an atmospheric chemistry module within the NASA GEOS-5 ESM. The coupled GEOS-5/GEOS-Chem system was tested for weak and strong scalability and performance with a tropospheric oxidant-aerosol simulation. Results confirm that the GEOS-Chem chemical operator scales efficiently for any number of processes. Although inclusion of atmospheric chemistry in ESMs is computationally expensive, the excellent scalability of the chemical operator means that the relative cost goes down with increasing number of processes, making fine-scale resolution simulations possible.
The Case for GEO Hosted SSA Payloads
NASA Astrophysics Data System (ADS)
Welsch, C.; Armand, B.; Repp, M.; Robinson, A.
2014-09-01
Space situational awareness (SSA) in the geosynchronous earth orbit (GEO) belt presents unique challenges, and given the national importance and high value of GEO satellites, is increasingly critical as space becomes more congested and contested. Space situational awareness capabilities can serve as an effective deterrent against potential adversaries if they provide accurate, timely, and persistent information and are resilient to the threat environment. This paper will demonstrate how simple optical SSA payloads hosted on GEO commercial and government satellites can complement the SSA mission and data provided by Space-Based Space Surveillance (SBSS) and the Geosynchronous Space Situational Awareness Program (GSSAP). GSSAP is built by Orbital Sciences Corporation and launched on July 28, 2014. Analysis performed for this paper will show how GEO hosted SSA payloads, working in combination with SBSS and GSSAP, can increase persistence and timely coverage of high value assets in the GEO belt. The potential to further increase GEO object identification and tracking accuracy by integrating SSA data from multiple sources across different viewing angles including GEO hosted SSA sources will be addressed. Hosting SSA payloads on GEO platforms also increases SSA mission architecture resiliency as the sensors are by distributed across multiple platforms including commercial platforms. This distributed architecture presents a challenging target for an adversary to attempt to degrade or disable. We will present a viable concept of operations to show how data from hosted SSA sensors could be integrated with SBSS and GSSAP data to present a comprehensive and more accurate data set to users. Lastly, we will present an acquisition approach using commercial practices and building on lessons learned from the Commercially Hosted Infra Red Payload CHIRP to demonstrate the affordability of GEO hosted SSA payloads.
NASA Astrophysics Data System (ADS)
Gietzel, Jan; Schaeben, Helmut; Gabriel, Paul
2014-05-01
The increasing relevance of geological information for policy and economy at transnational level has recently been recognized by the European Commission, who has called for harmonized information related to reserves and resources in the EU Member States. GeoMol's transnational approach responds to that, providing consistent and seamless 3D geological information of the Alpine Foreland Basins based on harmonized data and agreed methodologies. However, until recently no adequate tool existed to ensure full interoperability among the involved GSOs and to distribute the multi-dimensional information of a transnational project facing diverse data policy, data base systems and software solutions. In recent years (open) standards describing 2D spatial data have been developed and implemented in different software systems including production environments for 2D spatial data (like regular 2D-GI-Systems). Easy yet secured access to the data is of upmost importance and thus priority for any spatial data infrastructure. To overcome limitations conditioned by highly sophisticated and platform dependent geo modeling software packages functionalities of a web portals can be utilized. Thus, combining a web portal with a "check-in-check-out" system allows distributed organized editing of data and models but requires standards for the exchange of 3D geological information to ensure interoperability. Another major concern is the management of large models and the ability of 3D tiling into spatially restricted models with refined resolution, especially when creating countrywide models . Using GST ("Geosciences in Space and Time") developed initially at TU Bergakademie Freiberg and continuously extended by the company GiGa infosystems, incorporating these key issues and based on an object-relational data model, it is possible to check out parts or whole models for edits and check in again after modification. GST is the core of GeoMol's web-based collaborative environment designed to serve the GSOs concerned and the scientific community. Recently common users spaces have been installed providing a central access point to manage locally stored data at each of the project partners' IT sites. This distributed-organized system allows to keep the data of the live system locally and to share just cleared portions of the data, thus adhering to national regulations on geo data access. GST also allows for a dynamic generation of virtual drilling profiles and cross sections of the stored models. As this enables to deduce classified borehole data, a role based log in giving full access to the live system only for legally mandated or licensed bodies. The beta version of GeoMol's GST based geo data infrastructure and dissemination tool for multi-dimensional information, implemented incrementally, will be installed on GeoMol's website (http://geomol.eu) by end of February. It will be available for testing to further improve the performance and applicability of GeoMol's 3D-Explorer for instant web based access to GeoMol's future outputs. The project GeoMol is co-funded by the Alpine Space Program as part of the European Territorial Cooperation 2007-2013. The project integrates partners from Austria, France, Germany, Italy, Slovenia and Switzerland and runs from September 2012 to June 2015. Further information on http://geomol.eu.
GeoTrust Hub: A Platform For Sharing And Reproducing Geoscience Applications
NASA Astrophysics Data System (ADS)
Malik, T.; Tarboton, D. G.; Goodall, J. L.; Choi, E.; Bhatt, A.; Peckham, S. D.; Foster, I.; Ton That, D. H.; Essawy, B.; Yuan, Z.; Dash, P. K.; Fils, G.; Gan, T.; Fadugba, O. I.; Saxena, A.; Valentic, T. A.
2017-12-01
Recent requirements of scholarly communication emphasize the reproducibility of scientific claims. Text-based research papers are considered poor mediums to establish reproducibility. Papers must be accompanied by "research objects", aggregation of digital artifacts that together with the paper provide an authoritative record of a piece of research. We will present GeoTrust Hub (http://geotrusthub.org), a platform for creating, sharing, and reproducing reusable research objects. GeoTrust Hub provides tools for scientists to create `geounits'--reusable research objects. Geounits are self-contained, annotated, and versioned containers that describe and package computational experiments in an efficient and light-weight manner. Geounits can be shared on public repositories such as HydroShare and FigShare, and also using their respective APIs reproduced on provisioned clouds. The latter feature enables science applications to have a lifetime beyond sharing, wherein they can be independently verified and trust be established as they are repeatedly reused. Through research use cases from several geoscience laboratories across the United States, we will demonstrate how tools provided from GeoTrust Hub along with Hydroshare as its public repository for geounits is advancing the state of reproducible research in the geosciences. For each use case, we will address different computational reproducibility requirements. Our first use case will be an example of setup reproducibility which enables a scientist to set up and reproduce an output from a model with complex configuration and development environments. Our second use case will be an example of algorithm/data reproducibility, where in a shared data science model/dataset can be substituted with an alternate one to verify model output results, and finally an example of interactive reproducibility, in which an experiment is dependent on specific versions of data to produce the result. Toward this we will use software and data used in preparing data for the MODFLOW model in Hydrology, JupyterHub used in Hydroshare, PyLith used in Computational Infrastructure for Geodynamics, and GeoSpace Collaborative Observations and Assimilative Modeling used in space science. The GeoTrust Hub is funded through the National Science Foundation EarthCube program.
Lai, Yi-Syuan; Lee, Wan-Ching; Lin, Yu-En; Ho, Chi-Tang; Lu, Kuan-Hung; Lin, Shih-Hang; Panyod, Suraphan; Chu, Yung-Lin; Sheen, Lee-Yan
2016-03-16
The objective of this study was to investigate the hepatoprotective efficacy and mechanism of action of ginger essential oil (GEO) against the development of nonalcoholic fatty liver disease (NAFLD). Mice were maintained on either a control diet or high-fat diet (HFD) supplemented with GEO (12.5, 62.5, and 125 mg/kg) or citral (2.5 and 25 mg/kg) for 12 weeks. We demonstrated that GEO and its major component (citral) lowered HFD-induced obesity in a dose-dependent manner, accompanied by anti-hyperlipidemic effects by reducing serum free fatty acid, triglyceride, and total cholesterol levels. Moreover, liver histological results showed that administration of 62.5 and 125 mg/kg GEO and 25 mg/kg citral significantly reduced hepatic lipid accumulation. Further assessment by Western blotting and investigation of the lipid metabolism revealed that hepatic protein expression of sterol regulatory element-binding protein-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), and cytochrome P450 2E1 (CYP2E1) were down-regulated by GEO and citral, indicating that GEO and citral suppressed HFD-stimulated lipid biosynthesis and oxidative stress. Furthermore, GEO and citral effectively enhanced the antioxidant capacities and reduced inflammatory response in mouse liver, which exerted protective effects against steatohepatitis. Collectively, GEO and citral exhibited potent hepatoprotective effects against NAFLD induced by HFD in obese mice. Thus, GEO might be an effective dietary supplement to ameliorate NAFLD-related metabolic diseases, and citral could play a vital role in its management.
Geo-reCAPTCHA: Crowdsourcing large amounts of geographic information from earth observation data
NASA Astrophysics Data System (ADS)
Hillen, Florian; Höfle, Bernhard
2015-08-01
The reCAPTCHA concept provides a large amount of valuable information for various applications. First, it provides security, e.g., for a form on a website, by means of a test that only a human could solve. Second, the effort of the user for this test is used to generate additional information, e.g., digitization of books or identification of house numbers. In this work, we present a concept for adapting the reCAPTCHA idea to create user-generated geographic information from earth observation data, and the requirements during the conception and implementation are depicted in detail. Furthermore, the essential parts of a Geo-reCAPTCHA system are described, and afterwards transferred, to a prototype implementation. An empirical user study is conducted to investigate the Geo-reCAPTCHA approach, assessing time and quality of the resulting geographic information. Our results show that a Geo-reCAPTCHA can be solved by the users of our study on building digitization in a short amount of time (19.2 s on average) with an overall average accuracy of the digitizations of 82.2%. In conclusion, Geo-reCAPTCHA has the potential to be a reasonable alternative to the typical reCAPTCHA, and to become a new data-rich channel of crowdsourced geographic information.
Wei, Jyh-Da; Tsai, Ming-Hung; Lee, Gen-Cher; Huang, Jeng-Hung; Lee, Der-Tsai
2009-01-01
Algorithm visualization is a unique research topic that integrates engineering skills such as computer graphics, system programming, database management, computer networks, etc., to facilitate algorithmic researchers in testing their ideas, demonstrating new findings, and teaching algorithm design in the classroom. Within the broad applications of algorithm visualization, there still remain performance issues that deserve further research, e.g., system portability, collaboration capability, and animation effect in 3D environments. Using modern technologies of Java programming, we develop an algorithm visualization and debugging system, dubbed GeoBuilder, for geometric computing. The GeoBuilder system features Java's promising portability, engagement of collaboration in algorithm development, and automatic camera positioning for tracking 3D geometric objects. In this paper, we describe the design of the GeoBuilder system and demonstrate its applications.
A GeoWall with Physics and Astronomy Applications
NASA Astrophysics Data System (ADS)
Dukes, Phillip; Bruton, Dan
2008-03-01
A GeoWall is a passive stereoscopic projection system that can be used by students, teachers, and researchers for visualization of the structure and dynamics of three-dimensional systems and data. The type of system described here adequately provides 3-D visualization in natural color for large or small groups of viewers. The name ``GeoWall'' derives from its initial development to visualize data in the geosciences.1 An early GeoWall system was developed by Paul Morin at the electronic visualization laboratory at the University of Minnesota and was applied in an introductory geology course in spring of 2001. Since that time, several stereoscopic media, which are applicable to introductory-level physics and astronomy classes, have been developed and released into the public domain. In addition to the GeoWall's application in the classroom, there is considerable value in its use as part of a general science outreach program. In this paper we briefly describe the theory of operation of stereoscopic projection and the basic necessary components of a GeoWall system. Then we briefly describe how we are using a GeoWall as an instructional tool for the classroom and informal astronomy education and in research. Finally, we list sources for several of the free software media in physics and astronomy available for use with a GeoWall system.
NASA Astrophysics Data System (ADS)
Goldstein, N.; Dressler, R. A.; Richtsmeier, S. S.; McLean, J.; Dao, P. D.; Murray-Krezan, J.; Fulcoly, D. O.
2013-09-01
Recent ground testing of a wide area camera system and automated star removal algorithms has demonstrated the potential to detect, quantify, and track deep space objects using small aperture cameras and on-board processors. The camera system, which was originally developed for a space-based Wide Area Space Surveillance System (WASSS), operates in a fixed-stare mode, continuously monitoring a wide swath of space and differentiating celestial objects from satellites based on differential motion across the field of view. It would have greatest utility in a LEO orbit to provide automated and continuous monitoring of deep space with high refresh rates, and with particular emphasis on the GEO belt and GEO transfer space. Continuous monitoring allows a concept of change detection and custody maintenance not possible with existing sensors. The detection approach is equally applicable to Earth-based sensor systems. A distributed system of such sensors, either Earth-based, or space-based, could provide automated, persistent night-time monitoring of all of deep space. The continuous monitoring provides a daily record of the light curves of all GEO objects above a certain brightness within the field of view. The daily updates of satellite light curves offers a means to identify specific satellites, to note changes in orientation and operational mode, and to queue other SSA assets for higher resolution queries. The data processing approach may also be applied to larger-aperture, higher resolution camera systems to extend the sensitivity towards dimmer objects. In order to demonstrate the utility of the WASSS system and data processing, a ground based field test was conducted in October 2012. We report here the results of the observations made at Magdalena Ridge Observatory using the prototype WASSS camera, which has a 4×60° field-of-view , <0.05° resolution, a 2.8 cm2 aperture, and the ability to view within 4° of the sun. A single camera pointed at the GEO belt provided a continuous night-long record of the intensity and location of more than 50 GEO objects detected within the camera's 60-degree field-of-view, with a detection sensitivity similar to the camera's shot noise limit of Mv=13.7. Performance is anticipated to scale with aperture area, allowing the detection of dimmer objects with larger-aperture cameras. The sensitivity of the system depends on multi-frame averaging and an image processing algorithm that exploits the different angular velocities of celestial objects and SOs. Principal Components Analysis (PCA) is used to filter out all objects moving with the velocity of the celestial frame of reference. The resulting filtered images are projected back into an Earth-centered frame of reference, or into any other relevant frame of reference, and co-added to form a series of images of the GEO objects as a function of time. The PCA approach not only removes the celestial background, but it also removes systematic variations in system calibration, sensor pointing, and atmospheric conditions. The resulting images are shot-noise limited, and can be exploited to automatically identify deep space objects, produce approximate state vectors, and track their locations and intensities as a function of time.
Research on geo-ontology construction based on spatial affairs
NASA Astrophysics Data System (ADS)
Li, Bin; Liu, Jiping; Shi, Lihong
2008-12-01
Geo-ontology, a kind of domain ontology, is used to make the knowledge, information and data of concerned geographical science in the abstract to form a series of single object or entity with common cognition. These single object or entity can compose a specific system in some certain way and can be disposed on conception and given specific definition at the same time. Ultimately, these above-mentioned worked results can be expressed in some manners of formalization. The main aim of constructing geo-ontology is to get the knowledge of the domain of geography, and provide the commonly approbatory vocabularies in the domain, as well as give the definite definition about these geographical vocabularies and mutual relations between them in the mode of formalization at different hiberarchy. Consequently, the modeling tool of conception model of describing geographic Information System at the hiberarchy of semantic meaning and knowledge can be provided to solve the semantic conception of information exchange in geographical space and make them possess the comparatively possible characters of accuracy, maturity and universality, etc. In fact, some experiments have been made to validate geo-ontology. During the course of studying, Geo-ontology oriented to flood can be described and constructed by making the method based on geo-spatial affairs to serve the governmental departments at all levels to deal with flood. Thereinto, intelligent retrieve and service based on geoontology of disaster are main functions known from the traditional manner by using keywords. For instance, the function of dealing with disaster information based on geo-ontology can be provided when a supposed flood happened in a certain city. The correlative officers can input some words, such as "city name, flood", which have been realized semantic label, to get the information they needed when they browse different websites. The information, including basic geographical information and flood distributing and change about flood with different scales and ranges in the city, can be distilled intellectively and on its own initiative from the geo-ontology database. Besides, correlative statistical information can also be provided to the governmental departments at all levels to help them to carry out timely measures of fighting back disaster and rescue. Compared with the past manners, the efficiency of dealing with flood information has been improved to some extent than ever because plenty of information irrespective and interferential to flood in different websites can be sieved in advance based on the retrieve method oriented to Geo-ontology. In a word, it will take the pursuers long time to study geo-ontology due to actual limited resource. But then, geo-ontology will be sure to further perfect correspondingly especially in the field of Geographic Information System owing to its more and more factual applications.
Local Anodic Oxidation of Thin GeO Films and Formation of Nanostructures Based on Them
NASA Astrophysics Data System (ADS)
Astankova, K. N.; Kozhukhov, A. S.; Azarov, I. A.; Gorokhov, E. B.; Sheglov, D. V.; Latyshev, A. V.
2018-04-01
The process of local anodic oxidation of thin GeO films has been studied using an atomic force microscope. The electron-probe microanalysis showed that oxidized areas of a GeO film were germanium dioxide. The effect of the voltage pulse duration applied to the probe-substrate system and the atmospheric humidity on the height of the oxide structures has been studied. The kinetics of the local anodic oxidation (LAO) in a semi-contact mode obeys the Cabrera-Mott model for large times. The initial growth rate of the oxide ( R 0) significantly increases and the time of starting the oxidation ( t 0) decreases as the atmospheric humidity increases by 20%, which is related to an increase in the concentration of oxygen-containing ions at the surface of the oxidized GeO film. It was shown that nanostructures in thin GeO layers can be formed by the LAO method.
Diffractive optics technology and the NASA Geostationary Earth Observatory (GEO)
NASA Technical Reports Server (NTRS)
Morris, G. Michael; Michaels, Robert L.; Faklis, Dean
1992-01-01
Diffractive (or binary) optics offers unique capabilities for the development of large-aperture, high-performance, light-weight optical systems. The Geostationary Earth Observatory (GEO) will consist of a variety of instruments to monitor the environmental conditions of the earth and its atmosphere. The aim of this investigation is to analyze the design of the GEO instrument that is being proposed and to identify the areas in which diffractive (or binary) optics technology can make a significant impact in GEO sensor design. Several potential applications where diffractive optics may indeed serve as a key technology for improving the performance and reducing the weight and cost of the GEO sensors have been identified. Applications include the use of diffractive/refractive hybrid lenses for aft-optic imagers, diffractive telescopes for narrowband imaging, subwavelength structured surfaces for anti-reflection and polarization control, and aberration compensation for reflective imaging systems and grating spectrometers.
GeoViQua: quality-aware geospatial data discovery and evaluation
NASA Astrophysics Data System (ADS)
Bigagli, L.; Papeschi, F.; Mazzetti, P.; Nativi, S.
2012-04-01
GeoViQua (QUAlity aware VIsualization for the Global Earth Observation System of Systems) is a recently started FP7 project aiming at complementing the Global Earth Observation System of Systems (GEOSS) with rigorous data quality specifications and quality-aware capabilities, in order to improve reliability in scientific studies and policy decision-making. GeoViQua main scientific and technical objective is to enhance the GEOSS Common Infrastructure (GCI) providing the user community with innovative quality-aware search and evaluation tools, which will be integrated in the GEO-Portal, as well as made available to other end-user interfaces. To this end, GeoViQua will promote the extension of the current standard metadata for geographic information with accurate and expressive quality indicators, also contributing to the definition of a quality label (GEOLabel). GeoViQua proposed solutions will be assessed in several pilot case studies covering the whole Earth Observation chain, from remote sensing acquisition to data processing, to applications in the main GEOSS Societal Benefit Areas. This work presents the preliminary results of GeoViQua Work Package 4 "Enhanced geo-search tools" (WP4), started in January 2012. Its major anticipated technical innovations are search and evaluation tools that communicate and exploit data quality information from the GCI. In particular, GeoViQua will investigate a graphical search interface featuring a coherent and meaningful aggregation of statistics and metadata summaries (e.g. in the form of tables, charts), thus enabling end users to leverage quality constraints for data discovery and evaluation. Preparatory work on WP4 requirements indicated that users need the "best" data for their purpose, implying a high degree of subjectivity in judgment. This suggests that the GeoViQua system should exploit a combination of provider-generated metadata (objective indicators such as summary statistics), system-generated metadata (contextual/tracking information such as provenance of data and metadata), and user-generated metadata (informal user comments, usage information, rating, etc.). Moreover, metadata should include sufficiently complete access information, to allow rich data visualization and propagation. The following main enabling components are currently identified within WP4: - Quality-aware access services, e.g. a quality-aware extension of the OGC Sensor Observation Service (SOS-Q) specification, to support quality constraints for sensor data publishing and access; - Quality-aware discovery services, namely a quality-aware extension of the OGC Catalog Service for the Web (CSW-Q), to cope with quality constrained search; - Quality-augmentation broker (GeoViQua Broker), to support the linking and combination of the existing GCI metadata with GeoViQua- and user-generated metadata required to support the users in selecting the "best" data for their intended use. We are currently developing prototypes of the above quality-enabled geo-search components, that will be assessed in a sensor-based pilot case study in the next months. In particular, the GeoViQua Broker will be integrated with the EuroGEOSS Broker, to implement CSW-Q and federate (either via distribution or harvesting schemes) quality-aware data sources, GeoViQua will constitute a valuable test-bed for advancing the current best practices and standards in geospatial quality representation and exploitation. The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement n° 265178.
Usage Patterns of Open Genomic Data
ERIC Educational Resources Information Center
Xia, Jingfeng; Liu, Ying
2013-01-01
This paper uses Genome Expression Omnibus (GEO), a data repository in biomedical sciences, to examine the usage patterns of open data repositories. It attempts to identify the degree of recognition of data reuse value and understand how e-science has impacted a large-scale scholarship. By analyzing a list of 1,211 publications that cite GEO data…
USDA-ARS?s Scientific Manuscript database
The combined use of water erosion models and geographic information systems (GIS) has facilitated soil loss estimation at the watershed scale. Tools such as the Geo-spatial interface for the Water Erosion Prediction Project (GeoWEPP) model provide a convenient spatially distributed soil loss estimat...
NASA Technical Reports Server (NTRS)
Selkirk, Henry B.; Molod, Andrea M.
2014-01-01
Large-scale models such as GEOS-5 typically calculate grid-scale fractional cloudiness through a PDF parameterization of the sub-gridscale distribution of specific humidity. The GEOS-5 moisture routine uses a simple rectangular PDF varying in height that follows a tanh profile. While below 10 km this profile is informed by moisture information from the AIRS instrument, there is relatively little empirical basis for the profile above that level. ATTREX provides an opportunity to refine the profile using estimates of the horizontal variability of measurements of water vapor, total water and ice particles from the Global Hawk aircraft at or near the tropopause. These measurements will be compared with estimates of large-scale cloud fraction from CALIPSO and lidar retrievals from the CPL on the aircraft. We will use the variability measurements to perform studies of the sensitivity of the GEOS-5 cloud-fraction to various modifications to the PDF shape and to its vertical profile.
Visual mining geo-related data using pixel bar charts
NASA Astrophysics Data System (ADS)
Hao, Ming C.; Keim, Daniel A.; Dayal, Umeshwar; Wright, Peter; Schneidewind, Joern
2005-03-01
A common approach to analyze geo-related data is using bar charts or x-y plots. They are intuitive and easy to use. But important information often gets lost. In this paper, we introduce a new interactive visualization technique called Geo Pixel Bar Charts, which combines the advantages of Pixel Bar Charts and interactive maps. This technique allows analysts to visualize large amounts of spatial data without aggregation and shows the geographical regions corresponding to the spatial data attribute at the same time. In this paper, we apply Geo Pixel Bar Charts to visually mining sales transactions and Internet usage from different locations. Our experimental results show the effectiveness of this technique for providing data distribution and exceptions from the map.
NASA Technical Reports Server (NTRS)
Long, M. S.; Yantosca, R.; Nielsen, J. E; Keller, C. A.; Da Silva, A.; Sulprizio, M. P.; Pawson, S.; Jacob, D. J.
2015-01-01
The GEOS-Chem global chemical transport model (CTM), used by a large atmospheric chemistry research community, has been re-engineered to also serve as an atmospheric chemistry module for Earth system models (ESMs). This was done using an Earth System Modeling Framework (ESMF) interface that operates independently of the GEOSChem scientific code, permitting the exact same GEOSChem code to be used as an ESM module or as a standalone CTM. In this manner, the continual stream of updates contributed by the CTM user community is automatically passed on to the ESM module, which remains state of science and referenced to the latest version of the standard GEOS-Chem CTM. A major step in this re-engineering was to make GEOS-Chem grid independent, i.e., capable of using any geophysical grid specified at run time. GEOS-Chem data sockets were also created for communication between modules and with external ESM code. The grid-independent, ESMF-compatible GEOS-Chem is now the standard version of the GEOS-Chem CTM. It has been implemented as an atmospheric chemistry module into the NASA GEOS- 5 ESM. The coupled GEOS-5-GEOS-Chem system was tested for scalability and performance with a tropospheric oxidant-aerosol simulation (120 coupled species, 66 transported tracers) using 48-240 cores and message-passing interface (MPI) distributed-memory parallelization. Numerical experiments demonstrate that the GEOS-Chem chemistry module scales efficiently for the number of cores tested, with no degradation as the number of cores increases. Although inclusion of atmospheric chemistry in ESMs is computationally expensive, the excellent scalability of the chemistry module means that the relative cost goes down with increasing number of cores in a massively parallel environment.
Detection of Optically Faint GEO Debris
NASA Technical Reports Server (NTRS)
Seitzer, P.; Lederer, S.; Barker, E.; Cowardin, H.; Abercromby, K.; Silha, J.; Burkhardt, A.
2014-01-01
There have been extensive optical surveys for debris at geosynchronous orbit (GEO) conducted with meter-class telescopes, such as those conducted with MODEST (the Michigan Orbital DEbris Survey Telescope, a 0.6-m telescope located at Cerro Tololo in Chile), and the European Space Agency's 1.0-m space debris telescope (SDT) in the Canary Islands. These surveys have detection limits in the range of 18th or 19th magnitude, which corresponds to sizes larger than 10 cm assuming an albedo of 0.175. All of these surveys reveal a substantial population of objects fainter than R = 15th magnitude that are not in the public U.S. Satellite Catalog. To detect objects fainter than 20th magnitude (and presumably smaller than 10 cm) in the visible requires a larger telescope and excellent imaging conditions. This combination is available in Chile. NASA's Orbital Debris Program Office has begun collecting orbital debris observations with the 6.5-m (21.3-ft diameter) "Walter Baade" Magellan telescope at Las Campanas Observatory. The goal is to detect objects as faint as possible from a ground-based observatory and begin to understand the brightness distribution of GEO debris fainter than R = 20th magnitude.
Santos, P A S R; Avanço, G B; Nerilo, S B; Marcelino, R I A; Janeiro, V; Valadares, M C; Machinski, Miguel
2016-01-01
The objective of this study was to evaluate the cytotoxic activity of rosemary (REO, Rosmarinus officinalis L.), turmeric (CEO, Curcuma longa L.), and ginger (GEO, Zingiber officinale R.) essential oils in HeLa cells. Cytotoxicity tests were performed in vitro , using tetrazolium (MTT) and neutral red assays for evaluation of antiproliferative activity by different mechanisms, trypan blue assay to assess cell viability and evaluation of cell morphology for Giemsa to observe the cell damage, and Annexin V to evaluate cell death by apoptosis. CEO and GEO exhibited potent cytotoxic activity against HeLa cells. IC 50 obtained was 36.6 μ g/mL for CEO and 129.9 μ g/mL for GEO. The morphology of HeLa cells showed condensation of chromatin, loss of cell membrane integrity with protrusions (blebs), and cell content leakage for cells treated with CEO and GEO, from the lowest concentrations studied, 32.81 μ g/mL of CEO and 32.12 μ g/mL of GEO. The Annexin V assay revealed a profile of cell death by apoptosis for both CEO and GEO. The results indicate cytotoxic activity in vitro for CEO and GEO, suggesting potential use as anticancer agents for cervical cancer cells.
Santos, P. A. S. R.; Avanço, G. B.; Nerilo, S. B.; Marcelino, R. I. A.; Janeiro, V.; Valadares, M. C.
2016-01-01
The objective of this study was to evaluate the cytotoxic activity of rosemary (REO, Rosmarinus officinalis L.), turmeric (CEO, Curcuma longa L.), and ginger (GEO, Zingiber officinale R.) essential oils in HeLa cells. Cytotoxicity tests were performed in vitro, using tetrazolium (MTT) and neutral red assays for evaluation of antiproliferative activity by different mechanisms, trypan blue assay to assess cell viability and evaluation of cell morphology for Giemsa to observe the cell damage, and Annexin V to evaluate cell death by apoptosis. CEO and GEO exhibited potent cytotoxic activity against HeLa cells. IC50 obtained was 36.6 μg/mL for CEO and 129.9 μg/mL for GEO. The morphology of HeLa cells showed condensation of chromatin, loss of cell membrane integrity with protrusions (blebs), and cell content leakage for cells treated with CEO and GEO, from the lowest concentrations studied, 32.81 μg/mL of CEO and 32.12 μg/mL of GEO. The Annexin V assay revealed a profile of cell death by apoptosis for both CEO and GEO. The results indicate cytotoxic activity in vitro for CEO and GEO, suggesting potential use as anticancer agents for cervical cancer cells. PMID:28042599
Semantics-informed cartography: the case of Piemonte Geological Map
NASA Astrophysics Data System (ADS)
Piana, Fabrizio; Lombardo, Vincenzo; Mimmo, Dario; Giardino, Marco; Fubelli, Giandomenico
2016-04-01
In modern digital geological maps, namely those supported by a large geo-database and devoted to dynamical, interactive representation on WMS-WebGIS services, there is the need to provide, in an explicit form, the geological assumptions used for the design and compilation of the database of the Map, and to get a definition and/or adoption of semantic representation and taxonomies, in order to achieve a formal and interoperable representation of the geologic knowledge. These approaches are fundamental for the integration and harmonisation of geological information and services across cultural (e.g. different scientific disciplines) and/or physical barriers (e.g. administrative boundaries). Initiatives such as GeoScience Markup Language (last version is GeoSciML 4.0, 2015, http://www.geosciml.org) and the INSPIRE "Data Specification on Geology" http://inspire.jrc.ec.europa.eu/documents/Data_Specifications/INSPIRE_DataSpecification_GE_v3.0rc3.pdf (an operative simplification of GeoSciML, last version is 3.0 rc3, 2013), as well as the recent terminological shepherding of the Geoscience Terminology Working Group (GTWG) have been promoting information exchange of the geologic knowledge. Grounded on these standard vocabularies, schemas and data models, we provide a shared semantic classification of geological data referring to the study case of the synthetic digital geological map of the Piemonte region (NW Italy), named "GEOPiemonteMap", developed by the CNR Institute of Geosciences and Earth Resources, Torino (CNR IGG TO) and hosted as a dynamical interactive map on the geoportal of ARPA Piemonte Environmental Agency. The Piemonte Geological Map is grounded on a regional-scale geo-database consisting of some hundreds of GeologicUnits whose thousands instances (Mapped Features, polygons geometry) widely occur in Piemonte region, and each one is bounded by GeologicStructures (Mapped Features, line geometry). GeologicUnits and GeologicStructures have been spatially correlated through the whole region and described using the GeoSciML vocabularies. A hierarchical schema is provided for the Piemonte Geological Map that gives the parental relations between several orders of GeologicUnits referring to mostly recurring geological objects and main GeologicEvents, in a logical framework compliant with GeoSciML and INSPIRE data models. The classification criteria and the Hierarchy Schema used to define the GEOPiemonteMap Legend, as well as the intended meanings of the geological concepts used to achieve the overall classification schema, are explicitly described in several WikiGeo pages (implemented by "MediaWiki" open source software, https://www.mediawiki.org/wiki/MediaWiki). Moreover, a further step toward a formal classification of the contents (both data and interpretation) of the GEOPiemonteMap was triggered, by setting up an ontological framework, named "OntoGeonous", in order to achieve a thorough semantic characterization of the Map.
Fly-ash geo-polymer foamed concrete
NASA Astrophysics Data System (ADS)
Kargin, Aleksey; Baev, Vladimir; Mashkin, Nikolay
2017-01-01
In recent years, the interest of researchrs in using fly-ash as a raw material for the geo-polymer synthesis is increasing. Kuzbass region (in Russia) has a large amount of ash wastes generated, which defined the relevace of the study performed in this paper. Results of investigating load-bearing capacity of structural insulating material produced by geo-polymerization of fly-ash of Kemerovo hydro-electric power plant with the addition of complex activator are described in the paper. Hydrogen peroxide solution was used as the foaming agent. The activation time, the temperature of isothermal holding and hardening in normal conditions for all samples were constant. The compressive strength and the mean density of geo-polymer foamed concrete were determined. The influence of the material composition on its properties was revealed. It is found that of the geo-polymer foamed concrete with the optimum composition has hardness of 1,1-3,5 MPa at the density of 400 to 900 kg/m3. Thus, the production of the fly-ash geo-polymer concretes and mortars is feasible, justified and promising.
Geostationary Coastal and Air Pollution Events (GeoCAPE) Wide Angle Spectrometer (WAS)
NASA Technical Reports Server (NTRS)
Kotecki, Carl; Chu, Martha; Mannino, Antonio; Marx, Catherine Trout; Bowers, Gregory A.; Bolognese, Jeffrey A.; Matson, Elizabeth A.; McBirney, Thomas R.; Earle, Cleland P.; Choi, Michael K.;
2014-01-01
The GeoCAPE Wide Angle Spectrometer (WAS) Study was a revisit of the COEDI Study from 2012. The customer primary goals were to keep mass, volume and cost to a minimum while meeting the science objectives and maximizing flight opportunities by fitting on the largest number of GEO accommodations possible. Riding on a commercial GEO satellite minimizes total mission costs. For this study, it is desired to increase the coverage rate,km2min, while maintaining ground sample size, 375m, and spectral resolution, 0.4-0.5nm native resolution. To be able to do this, the IFOV was significantly increased, hence the wide angle moniker. The field of view for COEDI was +0.6 degrees or (2048) 375m ground pixels. The WAS Threshold (the IDL study baseline design) is +2.4 degrees IDL study baseline design) is +2.4 degrees.
Hardisty, Frank; Robinson, Anthony C.
2010-01-01
In this paper we present the GeoViz Toolkit, an open-source, internet-delivered program for geographic visualization and analysis that features a diverse set of software components which can be flexibly combined by users who do not have programming expertise. The design and architecture of the GeoViz Toolkit allows us to address three key research challenges in geovisualization: allowing end users to create their own geovisualization and analysis component set on-the-fly, integrating geovisualization methods with spatial analysis methods, and making geovisualization applications sharable between users. Each of these tasks necessitates a robust yet flexible approach to inter-tool coordination. The coordination strategy we developed for the GeoViz Toolkit, called Introspective Observer Coordination, leverages and combines key advances in software engineering from the last decade: automatic introspection of objects, software design patterns, and reflective invocation of methods. PMID:21731423
EnGeoMAP - geological applications within the EnMAP hyperspectral satellite science program
NASA Astrophysics Data System (ADS)
Boesche, N. K.; Mielke, C.; Rogass, C.; Guanter, L.
2016-12-01
Hyperspectral investigations from near field to space substantially contribute to geological exploration and mining monitoring of raw material and mineral deposits. Due to their spectral characteristics, large mineral occurrences and minefields can be identified from space and the spatial distribution of distinct proxy minerals be mapped. In the frame of the EnMAP hyperspectral satellite science program a mineral and elemental mapping tool was developed - the EnGeoMAP. It contains a basic mineral mapping and a rare earth element mapping approach. This study shows the performance of EnGeoMAP based on simulated EnMAP data of the rare earth element bearing Mountain Pass Carbonatite Complex, USA, and the Rodalquilar and Lomilla Calderas, Spain, which host the economically relevant gold-silver, lead-zinc-silver-gold and alunite deposits. The mountain pass image data was simulated on the basis of AVIRIS Next Generation images, while the Rodalquilar data is based on HyMap images. The EnGeoMAP - Base approach was applied to both images, while the mountain pass image data were additionally analysed using the EnGeoMAP - REE software tool. The results are mineral and elemental maps that serve as proxies for the regional lithology and deposit types. The validation of the maps is based on chemical analyses of field samples. Current airborne sensors meet the spatial and spectral requirements for detailed mineral mapping and future hyperspectral space borne missions will additionally provide a large coverage. For those hyperspectral missions, EnGeoMAP is a rapid data analysis tool that is provided to spectral geologists working in mineral exploration.
GeoMapApp as a platform for visualizing marine data from Polar Regions
NASA Astrophysics Data System (ADS)
Nitsche, F. O.; Ryan, W. B.; Carbotte, S. M.; Ferrini, V.; Goodwillie, A. M.; O'hara, S. H.; Weissel, R.; McLain, K.; Chinhong, C.; Arko, R. A.; Chan, S.; Morton, J. J.; Pomeroy, D.
2012-12-01
To maximize the investment in expensive fieldwork the resulting data should be re-used as much as possible. In addition, unnecessary duplication of data collection effort should be avoided. This becomes even more important if access to field areas is as difficult and expensive as it is in Polar Regions. Making existing data discoverable in an easy to use platform is key to improve re-use and avoid duplication. A common obstacle is that use of existing data is often limited to specialists who know of the data existence and also have the right tools to view and analyze these data. GeoMapApp is a free, interactive, map based tool that allows users to discover, visualize, and analyze a large number of data sets. In addition to a global view, it provides polar map projections for displaying data in Arctic and Antarctic areas. Data that have currently been added to the system include Arctic swath bathymetry data collected from the USCG icebreaker Healy. These data are collected almost continuously including from cruises where bathymetry is not the main objective and for which existence of the acquired data may not be well known. In contrast, existence of seismic data from the Antarctic continental margin is well known in the seismic community. They are archived at and can be accessed through the Antarctic Seismic Data Library System (SDLS). Incorporating these data into GeoMapApp makes an even broader community aware of these data and the custom interface, which includes capabilities to visualize and explore these data, allows users without specific software or knowledge of the underlying data format to access the data. In addition to investigating these datasets, GeoMapApp provides links to the actual data sources to allow specialists the opportunity to re-use the original data. Important identification of data sources and data references are achieved on different levels. For access to the actual Antarctic seismic data GeoMapApp links to the SDLS site, where users have to register before downloading the data and where they are informed about data owners. For the swath bathymetry data GeoMapApp links to an IEDA/MGDS web page for each cruise containing detailed information about investigators and surveys.
NASA Astrophysics Data System (ADS)
Voermans, Michiel; Mao, Zhun; Baartman, Jantiene EM; Stokes, Alexia
2017-04-01
Anthropogenic activities such as hydropower, mining and road construction in mountainous areas can induce and intensify mass wasting geo-hazards (e.g. landslides, gullies, rockslides). This represses local safety and socio-economic development, and endangers biodiversity at larger scale. Until today, data and knowledge to construct geo-hazard databases for further assessments are lacking. This applies in particular to countries with a recently emerged rapid economic growth, where there are no previous hazard documentations and where means to gain data from e.g. intensive fieldwork or VHR satellite imagery and DEM processing are lacking. Google Earth (GE, https://www.google.com/earth/) is a freely available and relatively simple virtual globe, map and geographical information program, which is potentially useful in detecting geo-hazards. This research aimed at (i) testing the capability of Google Earth to detect locations of geo-hazards and (ii) identifying factors affecting the diagnosing quality of the detection, including effects of geo-hazard dimensions, environs setting and professional background and effort of GE users. This was tested on nine geo-hazard sites following road segments in the Three Parallel Rivers Area in the Yunnan province of China, where geo-hazards are frequently occurring. Along each road site, the position and size of each geo-hazard was measured in situ. Next, independent diagnosers with varying professional experience (students, researchers, engineers etc.) were invited to detect geo-hazard occurrence along each of the eight sites via GE. Finally, the inventory and diagnostic data were compared to validate the objectives. Rates of detected geo-hazards from 30 diagnosers ranged from 10% to 48%. No strong correlations were found between the type and size of the geo-hazards and their detection rates. Also the years of expertise of the diagnosers proved not to make a difference, opposite to what may be expected. Meanwhile the amount of time spent by the diagnoser proved to be positively influencing the detectability. GE showed to be a useful tool in detecting mainly larger geo-hazards if diligently applied, and is therefore applicable to identify geo-hazard hotspots. The usability for further assessments such as sediment delivery estimations is questionable and further research should be carried out to give insight to its full potential.
Computerized ionospheric tomography based on geosynchronous SAR
NASA Astrophysics Data System (ADS)
Hu, Cheng; Tian, Ye; Dong, Xichao; Wang, Rui; Long, Teng
2017-02-01
Computerized ionospheric tomography (CIT) based on spaceborne synthetic aperture radar (SAR) is an emerging technique to construct the three-dimensional (3-D) image of ionosphere. The current studies are all based on the Low Earth Orbit synthetic aperture radar (LEO SAR) which is limited by long repeat period and small coverage. In this paper, a novel ionospheric 3-D CIT technique based on geosynchronous SAR (GEO SAR) is put forward. First, several influences of complex atmospheric environment on GEO SAR focusing are detailedly analyzed, including background ionosphere and multiple scattering effects (induced by turbulent ionosphere), tropospheric effects, and random noises. Then the corresponding GEO SAR signal model is constructed with consideration of the temporal-variant background ionosphere within the GEO SAR long integration time (typically 100 s to 1000 s level). Concurrently, an accurate total electron content (TEC) retrieval method based on GEO SAR data is put forward through subband division in range and subaperture division in azimuth, obtaining variant TEC value with respect to the azimuth time. The processing steps of GEO SAR CIT are given and discussed. Owing to the short repeat period and large coverage area, GEO SAR CIT has potentials of covering the specific space continuously and completely and resultantly has excellent real-time performance. Finally, the TEC retrieval and GEO SAR CIT construction are performed by employing a numerical study based on the meteorological data. The feasibility and correctness of the proposed methods are verified.
NASA Astrophysics Data System (ADS)
Kllogjeri, Pellumb
In present age we are witnesses and practioners of computer-based education which is highly speed progressing. The computer-based education allows educators and students to use educational programming language and e-tutors to teach and learn, to interact with one another and share together the results of their work. The computer-based education is done possible by special electronic tools among which the most important are the mathematical programmes. There are many mathematical programmes, but one which is being embraced and used by a daily increasing number of users throughout the world is GeoGebra. The recently published software GeoGebra by Markus Hohenwater (2004) explicitly links geometry and algebra. GeoGebra affords a bidirectional combination of geometry and algebra that differs from earlier software forms. The bidirectional combination means that, for instance, by typing in an equation in the algebra window, the graph of the equation will be shown in the dynamic and graphic window. This programme is so much preferred because of its three main features: the double representation of the mathematical object(geometric and algebraic), there are not strong requirements as to the age and the knowledge in using it(the students of the elementary school can use it as well) and, it is offered free of charge(simply by downloading it). In this paper we are concentrating in the double representation of the mathematical object and its advantages in explaining and forming mathematical concepts and performing operations, in the global opportunities for using GeoGebra and the benefits of using it by cooperating and sharing experiences.
NASA Astrophysics Data System (ADS)
Steinberg, P. D.; Bednar, J. A.; Rudiger, P.; Stevens, J. L. R.; Ball, C. E.; Christensen, S. D.; Pothina, D.
2017-12-01
The rich variety of software libraries available in the Python scientific ecosystem provides a flexible and powerful alternative to traditional integrated GIS (geographic information system) programs. Each such library focuses on doing a certain set of general-purpose tasks well, and Python makes it relatively simple to glue the libraries together to solve a wide range of complex, open-ended problems in Earth science. However, choosing an appropriate set of libraries can be challenging, and it is difficult to predict how much "glue code" will be needed for any particular combination of libraries and tasks. Here we present a set of libraries that have been designed to work well together to build interactive analyses and visualizations of large geographic datasets, in standard web browsers. The resulting workflows run on ordinary laptops even for billions of data points, and easily scale up to larger compute clusters when available. The declarative top-level interface used in these libraries means that even complex, fully interactive applications can be built and deployed as web services using only a few dozen lines of code, making it simple to create and share custom interactive applications even for datasets too large for most traditional GIS systems. The libraries we will cover include GeoViews (HoloViews extended for geographic applications) for declaring visualizable/plottable objects, Bokeh for building visual web applications from GeoViews objects, Datashader for rendering arbitrarily large datasets faithfully as fixed-size images, Param for specifying user-modifiable parameters that model your domain, Xarray for computing with n-dimensional array data, Dask for flexibly dispatching computational tasks across processors, and Numba for compiling array-based Python code down to fast machine code. We will show how to use the resulting workflow with static datasets and with simulators such as GSSHA or AdH, allowing you to deploy flexible, high-performance web-based dashboards for your GIS data or simulations without needing major investments in code development or maintenance.
GEO Label: User and Producer Perspectives on a Label for Geospatial Data
NASA Astrophysics Data System (ADS)
Lush, V.; Lumsden, J.; Masó, J.; Díaz, P.; McCallum, I.
2012-04-01
One of the aims of the Science and Technology Committee (STC) of the Group on Earth Observations (GEO) was to establish a GEO Label- a label to certify geospatial datasets and their quality. As proposed, the GEO Label will be used as a value indicator for geospatial data and datasets accessible through the Global Earth Observation System of Systems (GEOSS). It is suggested that the development of such a label will significantly improve user recognition of the quality of geospatial datasets and that its use will help promote trust in datasets that carry the established GEO Label. Furthermore, the GEO Label is seen as an incentive to data providers. At the moment GEOSS contains a large amount of data and is constantly growing. Taking this into account, a GEO Label could assist in searching by providing users with visual cues of dataset quality and possibly relevance; a GEO Label could effectively stand as a decision support mechanism for dataset selection. Currently our project - GeoViQua, - together with EGIDA and ID-03 is undertaking research to define and evaluate the concept of a GEO Label. The development and evaluation process will be carried out in three phases. In phase I we have conducted an online survey (GEO Label Questionnaire) to identify the initial user and producer views on a GEO Label or its potential role. In phase II we will conduct a further study presenting some GEO Label examples that will be based on Phase I. We will elicit feedback on these examples under controlled conditions. In phase III we will create physical prototypes which will be used in a human subject study. The most successful prototypes will then be put forward as potential GEO Label options. At the moment we are in phase I, where we developed an online questionnaire to collect the initial GEO Label requirements and to identify the role that a GEO Label should serve from the user and producer standpoint. The GEO Label Questionnaire consists of generic questions to identify whether users and producers believe a GEO Label is relevant to geospatial data; whether they want a single "one-for-all" label or separate labels that will serve a particular role; the function that would be most relevant for a GEO Label to carry; and the functionality that users and producers would like to see from common rating and review systems they use. To distribute the questionnaire, relevant user and expert groups were contacted at meetings or by email. At this stage we successfully collected over 80 valid responses from geospatial data users and producers. This communication will provide a comprehensive analysis of the survey results, indicating to what extent the users surveyed in Phase I value a GEO Label, and suggesting in what directions a GEO Label may develop. Potential GEO Label examples based on the results of the survey will be presented for use in Phase II.
Results of Long Term Life Tests of Large Scale Lithium-Ion Cells
NASA Astrophysics Data System (ADS)
Inoue, Takefumi; Imamura, Nobutaka; Miyanaga, Naozumi; Yoshida, Hiroaki; Komada, Kanemi
2008-09-01
High energy density Li-ion cells have been introduced to latest satellites and another space usage. We have started development of large scale Li-ion cells for space applications in 1997. The chemical design was fixed in 1999.It is very important to confirm life performance to apply satellite applications because it requires long mission life such as 15 years for GEO and 5 to 7 years for LEO. Therefore we started life test at various conditions. And the tests have reached 8 to 9 years in actual calendar time. Semi - accelerated GEO tests which gives both calendar and cycle loss have been reached 42 season that corresponds 21 years in orbit. The specific energy range is 120 - 130 Wh/kg at EOL. According to the test results, we have confirmed that our Li-ion cell meets general requirements for space application such as GEO and LEO with quite high specific energy.
A prototype system based on visual interactive SDM called VGC
NASA Astrophysics Data System (ADS)
Jia, Zelu; Liu, Yaolin; Liu, Yanfang
2009-10-01
In many application domains, data is collected and referenced by its geo-spatial location. Spatial data mining, or the discovery of interesting patterns in such databases, is an important capability in the development of database systems. Spatial data mining recently emerges from a number of real applications, such as real-estate marketing, urban planning, weather forecasting, medical image analysis, road traffic accident analysis, etc. It demands for efficient solutions for many new, expensive, and complicated problems. For spatial data mining of large data sets to be effective, it is also important to include humans in the data exploration process and combine their flexibility, creativity, and general knowledge with the enormous storage capacity and computational power of today's computers. Visual spatial data mining applies human visual perception to the exploration of large data sets. Presenting data in an interactive, graphical form often fosters new insights, encouraging the information and validation of new hypotheses to the end of better problem-solving and gaining deeper domain knowledge. In this paper a visual interactive spatial data mining prototype system (visual geo-classify) based on VC++6.0 and MapObject2.0 are designed and developed, the basic algorithms of the spatial data mining is used decision tree and Bayesian networks, and data classify are used training and learning and the integration of the two to realize. The result indicates it's a practical and extensible visual interactive spatial data mining tool.
Optical Properties of High Area-to-Mass Objects at GEO
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Schildknecht, Thomas; Musci, Reto; Flohrer, Tim; Barker, Ed; Stansbery, Eugene; Agapov, Vladimir; Rumyantsev, Vasilij; Biryukov, Vadym; Abercromby, Kira;
2007-01-01
There exists at GEO a significant population of faint debris (R > 15th magnitude) with high area-to-mass ratios (AMR) (1 to 30 sq m/kg). Their orbital elements (particularly eccentricity and inclination) are observed to change on the time-scale of a week. The consensus is that these objects may be fragments of multi-layer insulation (MLI) blankets. Their orbits are primarily perturbed by solar radiation pressure. In this paper we will report preliminary results from an international collaboration to investigate the unresolved optical properties of these objects. This population was originally discovered by the ESA Space Debris Telescope, and the bulk of the objects to be described here are based on discoveries made with this telescope. Additional objects were supplied by both Russia and the US Air Force. Follow-up optical observations were obtained for a sample of a dozen objects by MODEST (the Michigan Orbital DEbris Survey Telescope) located at Cerro Tololo Inter-American Observatory in Chile. Sequences of calibrated observations in filters B, V, Broad R, and I were obtained under photometric conditions. Multi-color photometric observations in B, V, R, and I band of the same objects were also acquired at the Zimmerwald 1-meter telescope, located near Bern, Switzerland. Light curves of selected high AMR objects will be shown with a temporal resolution of a few seconds and typically span about 10 minutes. Photometric observations of these objects were acquired at the Crimean Astrophysical Observatory (CrAO). This data set includes light curves of objects having high variability of brightness and observed with 2.6 m and 0.64 m class instruments. We will present an analysis of the observed magnitudes and colors, and their correlations (or lack of correlation) with orbital elements, and with predicted values for MLI fragments. This represents the first such collaborative observational program on faint debris at GEO.
NASA Astrophysics Data System (ADS)
Weinke, Elisabeth; Hölbling, Daniel; Albrecht, Florian; Friedl, Barbara
2017-04-01
Geo-hazards and their effects are distributed geographically over wide regions. The effective mapping and monitoring is essential for hazard assessment and mitigation. It is often best achieved using satellite imagery and new object-based image analysis approaches to identify and delineate geo-hazard objects (landslides, floods, forest fires, storm damages, etc.). At the moment, several local/national databases and platforms provide and publish data of different types of geo-hazards as well as web-based risk maps and decision support systems. Also, the European commission implemented the Copernicus Emergency Management Service (EMS) in 2015 that publishes information about natural and man-made disasters and risks. Currently, no platform for landslides or geo-hazards as such exists that enables the integration of the user in the mapping and monitoring process. In this study we introduce the concept of a spatial data infrastructure for object delineation, web-processing and service provision of landslide information with the focus on user interaction in all processes. A first prototype for the processing and mapping of landslides in Austria and Italy has been developed within the project Land@Slide, funded by the Austrian Research Promotion Agency FFG in the Austrian Space Applications Program ASAP. The spatial data infrastructure and its services for the mapping, processing and analysis of landslides can be extended to other regions and to all types of geo-hazards for analysis and delineation based on Earth Observation (EO) data. The architecture of the first prototypical spatial data infrastructure includes four main areas of technical components. The data tier consists of a file storage system and the spatial data catalogue for the management of EO-data, other geospatial data on geo-hazards, as well as descriptions and protocols for the data processing and analysis. An interface to extend the data integration from external sources (e.g. Sentinel-2 data) is planned for the possibility of rapid mapping. The server tier consists of java based web and GIS server. Sub and main services are part of the service tier. Sub services are for example map services, feature editing services, geometry services, geoprocessing services and metadata services. For (meta)data provision and to support data interoperability, web standards of the OGC and the rest-interface is used. Four central main services are designed and developed: (1) a mapping service (including image segmentation and classification approaches), (2) a monitoring service to monitor changes over time, (3) a validation service to analyze landslide delineations from different sources and (4) an infrastructure service to identify affected landslides. The main services use and combine parts of the sub services. Furthermore, a series of client applications based on new technology standards making use of the data and services offered by the spatial data infrastructure. Next steps include the design to extend the current spatial data infrastructure to other areas and geo-hazard types to develop a spatial data infrastructure that can assist targeted mapping and monitoring of geo-hazards on a global context.
[Fernand Braudel and the geo-history of civilizations].
Ribeiro, Guilherme
2011-03-01
The article discusses the valuable role of geography in the study of civilizations entitled Grammaire des civilisations (A history of civilizations), by French historian Fernand Braudel. It also focuses on the epistemological role of the concept of geo-history in Braudel's thought. The article's underlying assumption is that geography has been crucial to comprehending history over large spans of time.
Reduction of livelihood risk for river bank erosion affected villagers
NASA Astrophysics Data System (ADS)
Majumder, S. Sen; Fox, D. M.; Chakrabari, S.; Bhandari, G.
2014-12-01
Bank erosion process of the Ganga River created a serious livelihood risk for the villagers situated on left bank of the river in Malda district of the State of West Bengal, India since last four decades. Due to the erosion of agriculture land by the river, most of the villagers having agriculture as their only means of livelihood became jobless suddenly. Presently they are living in a miserable condition. One of the main objectives of this paper is to find out an alternative means of livelihood for the victims to improve their miserable socio-economic condition. It has been found from field survey that some erosion affected villagers have started to live and practice agriculture temporarily on the riverine islands (large and stable since thirteen years) as these islands have very fertile soil. If the re-emerged land plots can again be demarcated on the newly formed islands and distributed among the landless people to practice agriculture over there, then it will be a useful alternative livelihood strategy for the victims. The demarcation of re-emerged plots can be achieved by georeferencing the cadastral maps and then overlaying the plots on the present river course. In the present study area geo-referencing process of the cadastral maps became a serious issue as the study area has been very dynamic in terms of land cover and land use. Most of the villages were lost into the river course. Thus the common permanent features, required for geo-referencing, shown in the cadastral maps (surveyed during 1954-1962) were not found in the present satellite images. The second important objective of the present study is to develop a proper methodology for geo-referencing the cadastral maps of this area. The Spatial Adjustment Transformation and Automatic Digitization tools of Arc GIS were used to prepare geo-referenced plot maps. In Projective Transformation method the geometrically corrected block maps having village boundaries were used as source file. Then the georeferenced plot maps were overlaid on the present river course and the plots covered by islands or lands were extracted. For e.g., Gopalpur village contains nearly 29% of its total area as riverine island and 36% of total plots are covered by this island area. These plots can be distributed to the land less people so that they can utilize it and reduce their livelihood risk in future.
An efficient algorithm for orbital evolution of space debris
NASA Astrophysics Data System (ADS)
Abdel-Aziz, Y.; Abd El-Salam, F.
More than four decades of space exploration have led to accumulation of significant quantities of debris around the Earth. These objects range in size from a tiny piece of junk to a large inoperable satellite, although these objects that have small size they have high are-to-mass ratios, and consequently their orbits are strongly influenced by solar radiation pressure and atmospheric drag. So the increasing population of space debris object in the LEO, MEO and GEO present growing with time, serious hazard for the survival of operating spacecrafts, particularly satellites and astronomical observatories. Since the average collision velocity between any spacecraft orbiting in the LOE and debris objects is about 10 km/s and about 3 km/s in the GEO. Space debris may significantly disturb any satellite operations or cause catastrophic damage to a spacecraft itself. Applying different shielding techniques spacecraft my be protected against impacts of space debris with diameters smaller than 1 cm. For larger debris objects, only one effective method to avoid catastrophic consequence of collision is a manoeuvre that will change the spacecraft orbit. The necessary conditions in this case is to evaluate and predict future positions of the spacecraft and space debris with sufficient accuray. Numerical integration of equations of motion are used until now. Existing analytical methods can solve this problem only with low accuracy. Difficulties are caused mainly by the lack of satisfying analytical solution of the resonance problem for geosynchronous orbit as well as from the lack of efficient analytical theory combining luni-solar perturbation and solar radiation pressure with geopotential attraction. Numerical integration is time consuming in some cases, and then for qualitative analysis of the satellite's and debris's motion it is necessary to apply analytical solution. This is the reason for searching for an accurate model to evaluate the orbital position of the operating satellites and space debris. The present paper developes a second order theory of perturbations (in the sense of the Hori-Lie perturbation method), that include the geopotential effect, luni-solar perturbations, solar radiation pressure and atmospheric drag. Resonance and very long period perturbations are modeled with the use of semi-secular terms for a short time span predictions. We present a comparision of our analytical solution with numerical integration of motion for chosen artificial satellites at (Low, MEO, GEO), also for different spase debris objets with different are-to-mass ratios showing good accuracy of the theory.
Biobjective planning of GEO debris removal mission with multiple servicing spacecrafts
NASA Astrophysics Data System (ADS)
Jing, Yu; Chen, Xiao-qian; Chen, Li-hu
2014-12-01
The mission planning of GEO debris removal with multiple servicing spacecrafts (SScs) is studied in this paper. Specifically, the SScs are considered to be initially on the GEO belt, and they should rendezvous with debris of different orbital slots and different inclinations, remove them to the graveyard orbit and finally return to their initial locations. Three key problems should be resolved here: task assignment, mission sequence planning and transfer trajectory optimization for each SSc. The minimum-cost, two-impulse phasing maneuver is used for each rendezvous. The objective is to find a set of optimal planning schemes with minimum fuel cost and travel duration. Considering this mission as a hybrid optimal control problem, a mathematical model is proposed. A modified multi-objective particle swarm optimization is employed to address the model. Numerous examples are carried out to demonstrate the effectiveness of the model and solution method. In this paper, single-SSc and multiple-SSc scenarios with the same amount of fuel are compared. Numerous experiments indicate that for a definite GEO debris removal mission, that which alternative (single-SSc or multiple-SSc) is better (cost less fuel and consume less travel time) is determined by many factors. Although in some cases, multiple-SSc scenarios may perform worse than single-SSc scenarios, the extra costs are considered worth the gain in mission safety and robustness.
Impaired expression of importin/karyopherin {beta}1 leads to post-implantation lethality
DOE Office of Scientific and Technical Information (OSTI.GOV)
Miura, Katsutaka; Yoshinobu, Kumiko; Imaizumi, Takashi
2006-03-03
Importin {beta}1 (Imp{beta})/karyopherin {beta}1 (Kpnb1) mediates the nuclear import of a large variety of substrates. This study aimed to investigate the requirement for the Kpnb1 gene in mouse development, using a gene trap line, B6-CB-Ayu8108 {sup GtgeoIMEG} (Ayu8108 {sup geo}), in which the trap vector was inserted into the promoter region of the Kpnb1 gene, but in reverse orientation of the Kpnb1 gene. Ayu8108 {sup geo/geo} homozygous embryos could develop to the blastocyst stage, but died before embryonic day 5.5, and expression of the Kpnb1 gene in homozygous blastocysts was undetectable. We also replaced the {beta}geo gene with Imp{beta} cDNAmore » through Cre-mediated recombination to rescue Imp{beta} expression. Homozygous mice for the rescued allele Ayu8108 {sup Imp{beta}}{sup /Imp{beta}} were born and developed normally. These results demonstrated that the cause of post-implantation lethality of Ayu8108 {sup geo/geo} homozygous embryos was impaired expression of the Kpnb1 gene, indicating indispensable roles of Imp{beta}1 in early development of mice.« less
Optical Photometric Observations of GEO Debris
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Rodriquez-Cowardin, Heather M.; Barker, Edwin S.; Abercromby, Kira J.; Kelecy, Thomas M.; Horstman, Matt
2010-01-01
We report on a continuing program of optical photometric measurements of faint orbital debris at geosynchronous Earth orbit (GEO). These observations can be compared with laboratory studies of actual spacecraft materials in an effort to determine what the faint debris at GEO may be. We have optical observations from Cerro Tololo Inter-American Observatory (CTIO) in Chile of two samples of debris: 1. GEO objects discovered in a survey with the University of Michigan's 0.6-m aperture Curtis-Schmidt telescope MODEST (for Michigan Orbital DEbris Survey Telescope), and then followed up in real-time with the CTIO/SMARTS 0.9-m for orbits and photometry. Our goal is to determine 6 parameter orbits and measure colors for all objects fainter than R = 15 t11 magnitude that are discovered in the MODEST survey. 2. A smaller sample of high area to mass ratio (AMR) objects discovered independently, and acquired using predictions from orbits derived from independent tracking data collected days prior to the observations. Our optical observations in standard astronomical BVRI filters are done with either telescope, and with the telescope tracking the debris object at the object's angular rate. Observations in different filters are obtained sequentially. We have obtained 71 calibrated sequences of R-B-V-I-R magnitudes. A total of 66 of these sequences have 3 or more good measurements in all filters (not contaminated by star streaks or in Earth's shadow). Most of these sequences show brightness variations, but a small subset has observed brightness variations consistent with that expected from observational errors alone. The majority of these stable objects are redder than a solar color in both B-R and R-I. There is no dependence on color with brightness. For a smaller sample of objects we have observed with synchronized CCD cameras on the two telescopes. The CTIO 0.9-m observes in B, and MODEST in R. The CCD cameras are electronically linked together so that the start time and duration of observations are the same to better than 50 milliseconds. Thus, the B-R color is a true measure of the surface of the debris piece facing the telescopes for that observation. Any change in color reflects a real change in the debris surface. We will compare our observations with models and laboratory measurements of selected surfaces.
Multiscale Laboratory Infrastructure and Services to users: Plans within EPOS
NASA Astrophysics Data System (ADS)
Spiers, Chris; Willingshofer, Ernst; Drury, Martyn; Funiciello, Francesca; Rosenau, Matthias; Scarlato, Piergiorgio; Sagnotti, Leonardo; EPOS WG6, Corrado Cimarelli
2015-04-01
The participant countries in EPOS embody a wide range of world-class laboratory infrastructures ranging from high temperature and pressure experimental facilities, to electron microscopy, micro-beam analysis, analogue modeling and paleomagnetic laboratories. Most data produced by the various laboratory centres and networks are presently available only in limited "final form" in publications. Many data remain inaccessible and/or poorly preserved. However, the data produced at the participating laboratories are crucial to serving society's need for geo-resources exploration and for protection against geo-hazards. Indeed, to model resource formation and system behaviour during exploitation, we need an understanding from the molecular to the continental scale, based on experimental data. This contribution will describe the plans that the laboratories community in Europe is making, in the context of EPOS. The main objectives are: • To collect and harmonize available and emerging laboratory data on the properties and processes controlling rock system behaviour at multiple scales, in order to generate products accessible and interoperable through services for supporting research activities. • To co-ordinate the development, integration and trans-national usage of the major solid Earth Science laboratory centres and specialist networks. The length scales encompassed by the infrastructures included range from the nano- and micrometer levels (electron microscopy and micro-beam analysis) to the scale of experiments on centimetre sized samples, and to analogue model experiments simulating the reservoir scale, the basin scale and the plate scale. • To provide products and services supporting research into Geo-resources and Geo-storage, Geo-hazards and Earth System Evolution. If the EPOS Implementation Phase proposal presently under construction is successful, then a range of services and transnational activities will be put in place to realize these objectives.
Similarity of markers identified from cancer gene expression studies: observations from GEO.
Shi, Xingjie; Shen, Shihao; Liu, Jin; Huang, Jian; Zhou, Yong; Ma, Shuangge
2014-09-01
Gene expression profiling has been extensively conducted in cancer research. The analysis of multiple independent cancer gene expression datasets may provide additional information and complement single-dataset analysis. In this study, we conduct multi-dataset analysis and are interested in evaluating the similarity of cancer-associated genes identified from different datasets. The first objective of this study is to briefly review some statistical methods that can be used for such evaluation. Both marginal analysis and joint analysis methods are reviewed. The second objective is to apply those methods to 26 Gene Expression Omnibus (GEO) datasets on five types of cancers. Our analysis suggests that for the same cancer, the marker identification results may vary significantly across datasets, and different datasets share few common genes. In addition, datasets on different cancers share few common genes. The shared genetic basis of datasets on the same or different cancers, which has been suggested in the literature, is not observed in the analysis of GEO data. © The Author 2013. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.
Geo-oculus: high resolution multi-spectral earth imaging mission from geostationary orbit
NASA Astrophysics Data System (ADS)
Vaillon, L.; Schull, U.; Knigge, T.; Bevillon, C.
2017-11-01
Geo-Oculus is a GEO-based Earth observation mission studied by Astrium for ESA in 2008-2009 to complement the Sentinel missions, the space component of the GMES (Global Monitoring for Environment & Security). Indeed Earth imaging from geostationary orbit offers new functionalities not covered by existing LEO observation missions, like real-time monitoring and fast revisit capability of any location within the huge area in visibility of the satellite. This high revisit capability is exploited by the Meteosat meteorogical satellites, but with a spatial resolution (500 m nadir for the third generation) far from most of GMES needs (10 to 100 m). To reach such ground resolution from GEO orbit with adequate image quality, large aperture instruments (> 1 m) and high pointing stability (<< 1 μrad) are required, which are the major challenges of such missions. To address the requirements from the GMES user community, the Geo-Oculus mission is a combination of routine observations (daily systematic coverage of European coastal waters) with "on-demand" observation for event monitoring (e.g. disasters, fires and oil slicks). The instrument is a large aperture imaging telescope (1.5 m diameter) offering a nadir spatial sampling of 10.5 m (21 m worst case over Europe, below 52.5°N) in a PAN visible channel used for disaster monitoring. The 22 multi-spectral channels have resolutions over Europe ranging from 40 m in UV/VNIR (0.3 to 1 μm) to 750 m in TIR (10-12 μm).
NASA Technical Reports Server (NTRS)
Putnam, William M.
2011-01-01
Earth system models like the Goddard Earth Observing System model (GEOS-5) have been pushing the limits of large clusters of multi-core microprocessors, producing breath-taking fidelity in resolving cloud systems at a global scale. GPU computing presents an opportunity for improving the efficiency of these leading edge models. A GPU implementation of GEOS-5 will facilitate the use of cloud-system resolving resolutions in data assimilation and weather prediction, at resolutions near 3.5 km, improving our ability to extract detailed information from high-resolution satellite observations and ultimately produce better weather and climate predictions
Framework Resources Multiply Computing Power
NASA Technical Reports Server (NTRS)
2010-01-01
As an early proponent of grid computing, Ames Research Center awarded Small Business Innovation Research (SBIR) funding to 3DGeo Development Inc., of Santa Clara, California, (now FusionGeo Inc., of The Woodlands, Texas) to demonstrate a virtual computer environment that linked geographically dispersed computer systems over the Internet to help solve large computational problems. By adding to an existing product, FusionGeo enabled access to resources for calculation- or data-intensive applications whenever and wherever they were needed. Commercially available as Accelerated Imaging and Modeling, the product is used by oil companies and seismic service companies, which require large processing and data storage capacities.
Optimizing Orbital Debris Monitoring with Optical Telescopes
2010-09-01
poses an increasing risk to manned space missions and operational satellites ; however, the majority of debris large enough to cause catastrophic...cameras hosted on GEO- based satellites for monitoring GEO. Performance analysis indicates significant potential contributions of these systems as a...concerns over the long term-viability of the space environment and the resulting economic impacts. The 2007 China anti- satellite test and the 2009
NASA Astrophysics Data System (ADS)
Izham, Mohamad Yusoff; Muhamad Uznir, Ujang; Alias, Abdul Rahman; Ayob, Katimon; Wan Ruslan, Ismail
2011-04-01
Existing 2D data structures are often insufficient for analysing the dynamism of saturation excess overland flow (SEOF) within a basin. Moreover, all stream networks and soil surface structures in GIS must be preserved within appropriate projection plane fitting techniques known as georeferencing. Inclusion of 3D volumetric structure of the current soft geo-objects simulation model would offer a substantial effort towards representing 3D soft geo-objects of SEOF dynamically within a basin by visualising saturated flow and overland flow volume. This research attempts to visualise the influence of a georeference system towards the dynamism of overland flow coverage and total overland flow volume generated from the SEOF process using VSG data structure. The data structure is driven by Green-Ampt methods and the Topographic Wetness Index (TWI). VSGs are analysed by focusing on spatial object preservation techniques of the conformal-based Malaysian Rectified Skew Orthomorphic (MRSO) and the equidistant-based Cassini-Soldner projection plane under the existing geodetic Malaysian Revised Triangulation 1948 (MRT48) and the newly implemented Geocentric Datum for Malaysia (GDM2000) datum. The simulated result visualises deformation of SEOF coverage under different georeference systems via its projection planes, which delineate dissimilar computation of SEOF areas and overland flow volumes. The integration of Georeference, 3D GIS and the saturation excess mechanism provides unifying evidence towards successful landslide and flood disaster management through envisioning the streamflow generating process (mainly SEOF) in a 3D environment.
3D Geo: An Alternative Approach
NASA Astrophysics Data System (ADS)
Georgopoulos, A.
2016-10-01
The expression GEO is mostly used to denote relation to the earth. However it should not be confined to what is related to the earth's surface, as other objects also need three dimensional representation and documentation, like cultural heritage objects. They include both tangible and intangible ones. In this paper the 3D data acquisition and 3D modelling of cultural heritage assets are briefly described and their significance is also highlighted. Moreover the organization of such information, related to monuments and artefacts, into relational data bases and its use for various purposes, other than just geometric documentation is also described and presented. In order to help the reader understand the above, several characteristic examples are presented and their methodology explained and their results evaluated.
Optical Reflection Spectroscopy of GEO Objects
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Cardona, Tammaso; Lederer, Susan M.; Cowardin, Heather; Abercromby, Kira J.; Barker, Edwin S.; Bedard, Donald
2013-01-01
We report on optical reflection spectroscopy of geosynchronous (GEO) objects in the US Space Surveillance Network (SSN) catalog. These observations were obtained using imaging spectrographs on the 6.5-m Magellan telescopes at the Las Campanas Observatory in Chile. Our goal is to determine the composition of these objects by comparing these spectral observations with ground-based laboratory measurements of spacecraft materials. The observations are all low resolution (1 nm after smoothing) obtained through a 5 arcsecond wide slit and using a grism as the dispersing element. The spectral range covered was from 450 nm to 800 nm. All spectra were flux calibrated using observations of standard stars with the exact same instrumental setup. An effort was made to obtain all observations within a limited range of topocentric phase angle, although the solar incident angle is unknown due to the lack of any knowledge of the attitude of the observed surface at the time of observation.
NASA Astrophysics Data System (ADS)
Cowardin, H.; Abercromby, K.; Barker, E.; Seitzer, P.; Mulrooney, M.; Schildknecht, T.
Optical observations of orbital debris offer insights that differ from radar measurements (specifically the size parameter and wavelength regime). For example, time-dependent photometric data yield lightcurves in multiple bandpasses that aid in material identification and possible periodic orientations. This data can also be used to help identify shapes and optical properties at multiple phase angles. Capitalizing on optical data products and applying them to generate a more complete understanding of orbital space objects, is a key objective of NASA's Optical Measurement Program, and a primary driver for creation of the Optical Measurements Center (OMC). The OMC attempts to emulate space-based illumination conditions using equipment and techniques that parallel telescopic observations and source-target-sensor orientations. The OMC uses a 300 Watt Xenon arc lamp as a solar simulator, a CCD camera with Johnson/Bessel colored filters, and a robotic arm to orientate/rotate objects to simulate an objects orbit/rotational period. A high-resolution, high bandwidth (350nm-2500nm) Analytical Spectral Devices (ASD) spectrometer is also employed to baseline various material types. Since observation of GEO targets are generally restricted to the optical regime (due to radar range limitations), analysis of their properties is tailored to those revealed by optical data products. In this connection, much attention has been directed towards understanding the lightcurves of orbital debris with high area-to-mass (A/m) ratios (> 0.9 m2/kg). A small population of GEO debris was recently identified, which exhibits the properties of high A/m objects, such as variable eccentricities and inclinations -- a dynamical characteristic generally resulting from varying solar radiation pressure on high A/m objects. Materials such as multi-layered insulation (MLI) and solar panels are two examples of materials with high area-to mass ratios. Lightcurves for such objects can vary greatly (even for the same object under different illumination conditions). For example, specular reflections from multiple facets of the target surface (e.g. Mylar or Aluminized Kapton) can lead to erratic, orientation-dependent lightcurves. This paper will investigate published color photometric data for a series of orbital debris targets and compare it to the empirical photometric measurements generated in the OMC. The specific materials investigated (known to exist in GEO) are: an intact piece of MLI, separated layers of MLI, and multiple solar cells materials. Using the data acquired over specific rotational angles through different filters (B, V, R, I), a color index is acquired (B-R, R-I). As a secondary check, the spectrometer is used to define color indexes for the same material. Using these values and their associated lightcurves, this laboratory data is compared to observational data obtained on the 1m telescope of the Astronomical Institute of the University of Bern (AUIB) and the 0.9 m Small and Moderate Aperture Research Telescope System (SMARTS) telescope at Cerro Tololo Inter-American Observatory (CTIO). We will present laboratory generated lightcurves with color indexes of the high A/m materials alongside telescopic data of targets with high A/m values. We will discuss the relationship of laboratory to telescope data in the context of classification of GEO debris objects.
Mathematical Understanding of the Underprivileged Students through GeoGebra
NASA Astrophysics Data System (ADS)
Amam, A.; Fatimah, A. T.; Hartono, W.; Effendi, A.
2017-09-01
A student’s mathematical understanding in high school from poor families in the district of Ciamis is still low. After reviews the various literature and earlier research, consequently, researchers convince that learning mathematics with GeoGebra can help students improve for the better understanding. Our long-term goal of this research is to support the implementation of new curriculum, namely ICT-based learning mathematics. Another goal is to give a basic mastery skill regarding mathematics software to students from underprivileged families. Moreover, the specific objective of this study is to examine the students’ mathematical understanding from underprivileged families after the implementation of learning with GeoGebra. We use a quantitative comparative research method to determine differences in the mathematical understanding of students’ from underprivileged families before and after mathematics learning with GeoGebra. Accordingly, the students of senior high school from underprivileged family in Baregbeg, Ciamis district, are the population of this study. This research is using purposive sampling. The instrument is in the form of a test question, which is the test of mathematical understanding. Research results show that the mathematical understanding students’ from underprivileged families after the mathematics learning with GeoGebra becomes better than before. The novelty of this research is that students understand the material of trigonometry through the use of modules, aided by GeoGebra in learning activities. Thus, the understanding has an impact on improving students’ mathematical understanding. Students also master the use of GeoGebra Software. Implementing these two things will be very useful for the next lesson.
Scientific Contributions to GEO Global Earth Observation Priorities
NASA Astrophysics Data System (ADS)
Friedl, L.; Ledrew, E.
2009-12-01
Numerous counties and non-governmental organizations have produced documents, held workshops, and published reports in the past decade that identify Earth observation needs to meet their particular objectives. The Group on Earth Observations (GEO) has conducted a review of these documents, workshops, and reports to identify the priority observations common to many societal benefit areas. GEO has made a concerted effort to include materials from a broad range of user types, including scientific researchers, resource managers, and policy makers. GEO has also sought an international breadth in the materials reviewed, including observation priorities from developing countries. The activity will help GEO optimize the observations in GEOSS that are most likely to provide societal benefits, and GEO members will use the results of this meta-analysis to support investment decisions. The Earth observations in GEOSS serve scientific research and applications endeavors. As a primary user of ground-based, airborne, in situ, and space-based observations of the Earth, the scientific community has a significant voice and vested interest in the observations offered through GEOSS. Furthermore, the science and technology community will have opportunities to identify critical scientific/technological advances needed to produce any observations that are needed yet not currently available. In this paper, we will discuss this GEO effort to identify Earth observations priorities. We will present initial findings for some societal benefit areas and the overall meta-analysis. We will also discuss possible roles for the science and technology community to contribute to those priorities, such as scientific advances needed to achieve the observations or to realize societal benefits from the observations.
Ultrahigh-pressure polyamorphism in GeO2 glass with coordination number >6
NASA Astrophysics Data System (ADS)
Kono, Yoshio; Kenney-Benson, Curtis; Ikuta, Daijo; Shibazaki, Yuki; Wang, Yanbin; Shen, Guoyin
2016-03-01
Knowledge of pressure-induced structural changes in glasses is important in various scientific fields as well as in engineering and industry. However, polyamorphism in glasses under high pressure remains poorly understood because of experimental challenges. Here we report new experimental findings of ultrahigh-pressure polyamorphism in GeO2 glass, investigated using a newly developed double-stage large-volume cell. The Ge-O coordination number (CN) is found to remain constant at ∼6 between 22.6 and 37.9 GPa. At higher pressures, CN begins to increase rapidly and reaches 7.4 at 91.7 GPa. This transformation begins when the oxygen-packing fraction in GeO2 glass is close to the maximal dense-packing state (the Kepler conjecture = ∼0.74), which provides new insights into structural changes in network-forming glasses and liquids with CN higher than 6 at ultrahigh-pressure conditions.
Tether Transportation System Study
NASA Technical Reports Server (NTRS)
Bangham, M. E.; Lorenzini, E.; Vestal, L.
1998-01-01
The projected traffic to geostationary earth orbit (GEO) is expected to increase over the next few decades. At the same time, the cost of delivering payloads from the Earth's surface to low earth orbit (LEO) is projected to decrease, thanks in part to the Reusable Launch Vehicle (RLV). A comparable reduction in the cost of delivering payloads from LEO to GEO is sought. The use of in-space tethers, eliminating the requirement for traditional chemical upper stages and thereby reducing the launch mass, has been identified as such an alternative. Spinning tethers are excellent kinetic energy storage devices for providing the large delta vee's required for LEO to GEO transfer. A single-stage system for transferring payloads from LEO to GEO was proposed some years ago. The study results presented here contain the first detailed analyses of this proposal, its extension to a two-stage system, and the likely implementation of the operational system.
GeoCENS: a geospatial cyberinfrastructure for the world-wide sensor web.
Liang, Steve H L; Huang, Chih-Yuan
2013-10-02
The world-wide sensor web has become a very useful technique for monitoring the physical world at spatial and temporal scales that were previously impossible. Yet we believe that the full potential of sensor web has thus far not been revealed. In order to harvest the world-wide sensor web's full potential, a geospatial cyberinfrastructure is needed to store, process, and deliver large amount of sensor data collected worldwide. In this paper, we first define the issue of the sensor web long tail followed by our view of the world-wide sensor web architecture. Then, we introduce the Geospatial Cyberinfrastructure for Environmental Sensing (GeoCENS) architecture and explain each of its components. Finally, with demonstration of three real-world powered-by-GeoCENS sensor web applications, we believe that the GeoCENS architecture can successfully address the sensor web long tail issue and consequently realize the world-wide sensor web vision.
Single-crystal X-ray diffraction study of SrGeO3 high-pressure perovskite phase at 100 K
NASA Astrophysics Data System (ADS)
Nakatsuka, Akihiko; Arima, Hiroshi; Ohtaka, Osamu; Fujiwara, Keiko; Yoshiasa, Akira
2017-10-01
Single-crystal X-ray diffraction study of SrGeO3 perovskite (cubic; space group Pmɜ¯m) synthesized at 6 GPa and 1223 K was conducted at a low temperature of 100 K. The residual electron density revealed the presence of the bonding electron at the center of the Ge-O bond, in accordance with our previous conclusion that the Ge-O bond is strongly covalent. From comparison with our previous structure-refinement result at 296 K, the mean square displacement (MSD) of the O atom in the direction of the Ge-O bond is suggested to exhibit no significant temperature dependence, in contrast to that in the direction perpendicular to the bond. Thus, the strong covalency of the Ge-O bond can have a large influence on the temperature dependence of thermal vibration of the O atom.
High voltage space plasma interactions. [charging the solar power satellites
NASA Technical Reports Server (NTRS)
Mccoy, J. E.
1980-01-01
Two primary problems resulted from plasma interactions; one of concern to operations in geosynchronous orbit (GEO), the other in low orbits (LEO). The two problems are not the same. Spacecraft charging has become widely recognized as a problem, particularly for communications satellites operating in GEO. The very thin thermal plasmas at GEO are insufficient to bleed off voltage buildups due to higher energy charged particle radiation collected on outer surfaces. Resulting differential charging/discharging causes electrical transients, spurious command signals and possible direct overload damage. An extensive NASA/Air Force program has been underway for several years to address this problem. At lower altitudes, the denser plasmas of the plasmasphere/ionosphere provide sufficient thermal current to limit such charging to a few volts or less. Unfortunately, these thermal plasma currents which solve the GEO spacecraft charging problem can become large enough to cause just the opposite problem in LEO.
GeoCENS: A Geospatial Cyberinfrastructure for the World-Wide Sensor Web
Liang, Steve H.L.; Huang, Chih-Yuan
2013-01-01
The world-wide sensor web has become a very useful technique for monitoring the physical world at spatial and temporal scales that were previously impossible. Yet we believe that the full potential of sensor web has thus far not been revealed. In order to harvest the world-wide sensor web's full potential, a geospatial cyberinfrastructure is needed to store, process, and deliver large amount of sensor data collected worldwide. In this paper, we first define the issue of the sensor web long tail followed by our view of the world-wide sensor web architecture. Then, we introduce the Geospatial Cyberinfrastructure for Environmental Sensing (GeoCENS) architecture and explain each of its components. Finally, with demonstration of three real-world powered-by-GeoCENS sensor web applications, we believe that the GeoCENS architecture can successfully address the sensor web long tail issue and consequently realize the world-wide sensor web vision. PMID:24152921
Active Space Debris Charging for Contactless Electrostatic Disposal Maneuvers
NASA Astrophysics Data System (ADS)
Schaub, H.; Sternovsky, Z.
2013-08-01
We assess the feasibility of removing large space debris from geosynchronous orbit (GEO) by means of a tug spacecraft that uses electrostatic forces to pull the debris without touching. The advantage of this method is that it can operate with a separation distance of multiple craft radii, thus reducing the risk of collision. Further, the debris does not have to be detumbled first to engage the re-orbit maneuver. The charging of the tug-debris system to high potentials is achieved by active charge transfer using a directed electron beam and an auxiliary ion bleeder. Our simple charging model takes into account the primary electron beam current, UV induced photoelectron emission, collection of plasma particles, secondary electron emission and the recapture of emitted particles. The results show that by active charging high potentials can be both achieved and maintained. The resulting mN level electrostatic force is sufficient for the safe re-orbiting of debris objects over an acceptable period of a few months. The capability of debris removal is becoming a pressing need as the increasing population of dysfunctional satellites poses a threat to the future of satellite operations at GEO.
NASA Astrophysics Data System (ADS)
Guo, Peng; Cheng, Wenming; Wang, Yi
2014-10-01
The quay crane scheduling problem (QCSP) determines the handling sequence of tasks at ship bays by a set of cranes assigned to a container vessel such that the vessel's service time is minimized. A number of heuristics or meta-heuristics have been proposed to obtain the near-optimal solutions to overcome the NP-hardness of the problem. In this article, the idea of generalized extremal optimization (GEO) is adapted to solve the QCSP with respect to various interference constraints. The resulting GEO is termed the modified GEO. A randomized searching method for neighbouring task-to-QC assignments to an incumbent task-to-QC assignment is developed in executing the modified GEO. In addition, a unidirectional search decoding scheme is employed to transform a task-to-QC assignment to an active quay crane schedule. The effectiveness of the developed GEO is tested on a suite of benchmark problems introduced by K.H. Kim and Y.M. Park in 2004 (European Journal of Operational Research, Vol. 156, No. 3). Compared with other well-known existing approaches, the experiment results show that the proposed modified GEO is capable of obtaining the optimal or near-optimal solution in a reasonable time, especially for large-sized problems.
Automatic Geo-location Correction of Satellite Imagery
2014-09-25
orientation of large stereo satellite image blocks.," Int. Arch. Photogrammetry and Remote Sensing Spatial Inf. Sci, vol. 39, pp. 209-214, 2012. [6...Coefficient (RPC) model to represent both the internal and external orientation of a satellite image in one Automatic Geo-location Correction of Satellite...Applications of Digital Image Processing VI, vol. 432, 1983. [9] Edward M Mikhail, James S Bethel, and J C McGlone, Introduction to Modern Photogrammetry
2007-09-19
extended object relations such as boundary, interior, open, closed , within, connected, and overlaps, which are invariant under elastic deformation...is required in a geo-spatial semantic web is challenging because the defining properties of geographic entities are very closely related to space. In...Objects under Primitive will be open (i.e., they will not contain their boundary points) and the objects under Complex will be closed . In addition to
NASA Technical Reports Server (NTRS)
Liu, Hongyu; Crawford, James H.; Considine, David B.; Platnick, Steven; Norris, Peter M.; Duncan, Bryan N.; Pierce, Robert B.; Chen, Gao; Yantosca, Robert M.
2009-01-01
Clouds affect tropospheric photochemistry through modification of solar radiation that determines photolysis frequencies. As a follow-up study to our recent assessment of the radiative effects of clouds on tropospheric chemistry, this paper presents an analysis of the sensitivity of such effects to cloud vertical distributions and optical properties (cloud optical depths (CODs) and cloud single scattering albedo), in a global 3-D chemical transport model (GEOS-Chem). GEOS-Chem was driven with a series of meteorological archives (GEOS1- STRAT, GEOS-3 and GEOS-4) generated by the NASA Goddard Earth Observing System data assimilation system. Clouds in GEOS1-STRAT and GEOS-3 have more similar vertical distributions (with substantially smaller CODs in GEOS1-STRAT) while those in GEOS-4 are optically much thinner in the tropical upper troposphere. We find that the radiative impact of clouds on global photolysis frequencies and hydroxyl radical (OH) is more sensitive to the vertical distribution of clouds than to the magnitude of column CODs. With random vertical overlap for clouds, the model calculated changes in global mean OH (J(O1D), J(NO2)) due to the radiative effects of clouds in June are about 0.0% (0.4%, 0.9%), 0.8% (1.7%, 3.1%), and 7.3% (4.1%, 6.0%), for GEOS1-STRAT, GEOS-3 and GEOS-4, respectively; the geographic distributions of these quantities show much larger changes, with maximum decrease in OH concentrations of approx.15-35% near the midlatitude surface. The much larger global impact of clouds in GEOS-4 reflects the fact that more solar radiation is able to penetrate through the optically thin upper-tropospheric clouds, increasing backscattering from low-level clouds. Model simulations with each of the three cloud distributions all show that the change in the global burden of ozone due to clouds is less than 5%. Model perturbation experiments with GEOS-3, where the magnitude of 3-D CODs are progressively varied from -100% to 100%, predict only modest changes (<5%) in global mean OH concentrations. J(O1D), J(NO2) and OH3 concentrations show the strongest sensitivity for small CODs and become insensitive at large CODs due to saturation effects. Caution should be exercised not to use in photochemical models a value for cloud single scattering albedo lower than about 0.999 in order to be consistent with the current knowledge of cloud absorption at the ultraviolet wavelengths.
Earth Observation in Environmental and Societal Impacts of Mineral Resources Exploitation
NASA Astrophysics Data System (ADS)
Chevrel, Stephane
Several national and international initiatives, both from the private or the institutional sectors, arised to address the sustainable development of the extractive industry and the reduction of its environmental footprint. Meanwhile, the extractive industry is facing increasing environmental and societal pressures, being regulatory or not, during all phases of a project, from exploration to exploitation and closure. The social acceptability of a project is among the major key issues to be dealt with. The EO-MINERS project (Earth Observation for Monitoring and Observing Environmental and Societal Impacts of Mineral Resources Exploration and Exploitation) is a newly EU funded Research and Technological Development project started in February 2010. EO-MINERS scientific and technical objectives are to: i) assess policy requirements at macro (public) and micro (mining companies) levels and define environmental, socio-economic, societal and sustainable development criteria and indicators to be possibly dealt using EO (Earth Observation); ii) use existing EO knowledge and carry out new developments on demonstration sites to further demonstrate the capabilities of integrated EO-based methods and tools in monitoring, managing and contributing reducing the environmental and societal footprints of the extractive industry during all phases of a mining project, from the exploration to the exploitation and closure stages; iii) contribute making reliable and objective information about affected ecosystems, populations and societies, to serve as a basis for a sound "trialogue" between industrialists, governmental organisations and stakeholders. EO-MINERS also is designed to embed the outcomes of the project firmly in the GEO process through a review the existing GEO Tasks covering the 9 societal benefit and 5 transverse areas defined by GEO work plan 2007-2009. This analysis will be used to identify synergies and gaps between EO-MINERS and GEO, with the aim of mapping mining and environmental observa-tion systems into the 9 GEOSS Societal Benefit Areas, identifying EO-MINERS contributions to existing GEOSS targets and defining new, EO-MINERS activities in support of GEOSS. EO-MINERS will run a minerals workshop with GEO members and/or the GEO Secretariat.
GeoSciML v3.0 - a significant upgrade of the CGI-IUGS geoscience data model
NASA Astrophysics Data System (ADS)
Raymond, O.; Duclaux, G.; Boisvert, E.; Cipolloni, C.; Cox, S.; Laxton, J.; Letourneau, F.; Richard, S.; Ritchie, A.; Sen, M.; Serrano, J.-J.; Simons, B.; Vuollo, J.
2012-04-01
GeoSciML version 3.0 (http://www.geosciml.org), released in late 2011, is the latest version of the CGI-IUGS* Interoperability Working Group geoscience data interchange standard. The new version is a significant upgrade and refactoring of GeoSciML v2 which was released in 2008. GeoSciML v3 has already been adopted by several major international interoperability initiatives, including OneGeology, the EU INSPIRE program, and the US Geoscience Information Network, as their standard data exchange format for geoscience data. GeoSciML v3 makes use of recently upgraded versions of several Open Geospatial Consortium (OGC) and ISO data transfer standards, including GML v3.2, SWE Common v2.0, and Observations and Measurements v2 (ISO 19156). The GeoSciML v3 data model has been refactored from a single large application schema with many packages, into a number of smaller, but related, application schema modules with individual namespaces. This refactoring allows the use and future development of modules of GeoSciML (eg; GeologicUnit, GeologicStructure, GeologicAge, Borehole) in smaller, more manageable units. As a result of this refactoring and the integration with new OGC and ISO standards, GeoSciML v3 is not backwardly compatible with previous GeoSciML versions. The scope of GeoSciML has been extended in version 3.0 to include new models for geomorphological data (a Geomorphology application schema), and for geological specimens, geochronological interpretations, and metadata for geochemical and geochronological analyses (a LaboratoryAnalysis-Specimen application schema). In addition, there is better support for borehole data, and the PhysicalProperties model now supports a wider range of petrophysical measurements. The previously used CGI_Value data type has been superseded in favour of externally governed data types provided by OGC's SWE Common v2 and GML v3.2 data standards. The GeoSciML v3 release includes worked examples of best practice in delivering geochemical analytical data using the Observations and Measurements (ISO19156) and SWE Common v2 models. The GeoSciML v3 data model does not include vocabularies to support the data model. However, it does provide a standard pattern to reference controlled vocabulary concepts using HTTP-URIs. The international GeoSciML community has developed distributed RDF-based geoscience vocabularies that can be accessed by GeoSciML web services using the standard pattern recommended in GeoSciML v3. GeoSciML v3 is the first version of GeoSciML that will be accompanied by web service validation tools using Schematron rules. For example, these validation tools may check for compliance of a web service to a particular profile of GeoSciML, or for logical consistency of data content that cannot be enforced by the application schemas. This validation process will support accreditation of GeoSciML services and a higher degree of semantic interoperability. * International Union of Geological Sciences Commission for Management and Application of Geoscience Information (CGI-IUGS)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lowry, Thomas Stephen; Finger, John T.; Carrigan, Charles R.
This report documents the key findings from the Reservoir Maintenance and Development (RM&D) Task of the U.S. Department of Energy's (DOE), Geothermal Technologies Office (GTO) Geothermal Vision Study (GeoVision Study). The GeoVision Study had the objective of conducting analyses of future geothermal growth based on sets of current and future geothermal technology developments. The RM&D Task is one of seven tasks within the GeoVision Study with the others being, Exploration and Confirmation, Potential to Penetration, Institutional Market Barriers, Environmental and Social Impacts, Thermal Applications, and Hybrid Systems. The full set of findings and the details of the GeoVision Study canmore » be found in the final GeoVision Study report on the DOE-GTO website. As applied here, RM&D refers to the activities associated with developing, exploiting, and maintaining a known geothermal resource. It assumes that the site has already been vetted and that the resource has been evaluated to be of sufficient quality to move towards full-scale development. It also assumes that the resource is to be developed for power generation, as opposed to low-temperature or direct use applications. This document presents the key factors influencing RM&D from both a technological and operational standpoint and provides a baseline of its current state. It also looks forward to describe areas of research and development that must be pursued if the development geothermal energy is to reach its full potential.« less
Mining moving object trajectories in location-based services for spatio-temporal database update
NASA Astrophysics Data System (ADS)
Guo, Danhuai; Cui, Weihong
2008-10-01
Advances in wireless transmission and mobile technology applied to LBS (Location-based Services) flood us with amounts of moving objects data. Vast amounts of gathered data from position sensors of mobile phones, PDAs, or vehicles hide interesting and valuable knowledge and describe the behavior of moving objects. The correlation between temporal moving patterns of moving objects and geo-feature spatio-temporal attribute was ignored, and the value of spatio-temporal trajectory data was not fully exploited too. Urban expanding or frequent town plan change bring about a large amount of outdated or imprecise data in spatial database of LBS, and they cannot be updated timely and efficiently by manual processing. In this paper we introduce a data mining approach to movement pattern extraction of moving objects, build a model to describe the relationship between movement patterns of LBS mobile objects and their environment, and put up with a spatio-temporal database update strategy in LBS database based on trajectories spatiotemporal mining. Experimental evaluation reveals excellent performance of the proposed model and strategy. Our original contribution include formulation of model of interaction between trajectory and its environment, design of spatio-temporal database update strategy based on moving objects data mining, and the experimental application of spatio-temporal database update by mining moving objects trajectories.
Towards the Implementation of the GEOSS Water Strategy
NASA Astrophysics Data System (ADS)
Lawford, R. G.; Cripe, D.
2014-12-01
Early in 2014, the Group on Earth Observations (GEO) adopted the GEOSS (Global Earth Observation System of Systems) Water Strategy as a potential guide for GEO-related water activities over the next decade. The Water Strategy outlines water-related issues and opportunities that fit within the general GEOSS framework that will be developed over the next decade (2016-2025). Implementation of a water strategy within the GEOSS framework can be complex because GEO Members and Participating Organizations contribute to GEO on a voluntary basis. In spite of these limitations efforts to consolidate an implementation plan have made significant advances during the past nine months. Progress towards the final GEOSS Water Strategy Implementation Plan will be reported and gaps in the plan will be identified. Specific responses to the strategy will address the need for user engagement, the development of integrated of data products, model hierarchies and user support systems, and the research that will be needed to expand the capabilities of GEOSS and its water services. One challenge for the implementation plan involves building a framework from the diverse and wide range of activities and opportunities presented by GEO Members and Participating Organizations. The priority themes within the GEO Water Strategy are being used to provide more focus for new initiatives. New activities related to these priority areas involving projects that link water and other GEO Societal Benefit Areas, as well as initiatives related to the Water-Energy-Food nexus and the Sustainable Development Goals will be described. The presentation will also explore the needs and opportunities for new satellites and other observational and information technologies to advance the implementation of the GEOSS water strategy objectives.
An LO Phase Link Using a Commercial Geo-Stationary Satellite
NASA Technical Reports Server (NTRS)
Bardin, Joseph C.; Weinreb, Sander; Bagri, Durgadas S.
2005-01-01
This viewgraph presentation reviews an experiment to determine feasibility of achieving 1 ps level time transfer using a satellite link and make use of inexpensive Ku band transmit/receive equipment. It reviews the advantages of Two Way Satellite Time Transfer using a commercial Geo-Stationary Satellite: (1) Commercial satellites are available (2) Significant cost reduction when compared to Hydrogen Masers and (3) Large footprint- entire US (including Hawaii) with just one satellite.
Retrieving SW fluxes from geostationary narrowband radiances for the NASA-CERES SYN1deg product
NASA Astrophysics Data System (ADS)
Wrenn, F. J., IV; Doelling, D. R.; Liang, L.
2016-12-01
The CERES mission was designed to measure the natural variability of the net TOA flux over long time scales relevant to climate monitoring. To achieve this goal, CERES provides the level-3 SSF1deg, SYN1deg, and EBAF monthly 1° by 1° regional TOA flux. The single satellite (Terra or Aqua) SSF1deg 24-hour shortwave flux is based on one daytime measurements and assumes constant meteorology to model the diurnal change in albedo. To accurately describe regions with a prominent diurnal signal, the SYN1deg Edition4 dataset employs hourly geostationary (GEO) measurements. This improves upon Edition3, which used 3-hourly GEO measurements and with temporal interpolation. The EBAF product combines the temporal stability of the SSF1deg product with the diurnal information from SYN1deg and removes the CERES instrument calibration bias by constraining the net flux balance to the ocean heat storage term. The SYN-1deg product retrieves hourly SW fluxes from GEO measurements. Over regions with large diurnal cycles, such as maritime stratus and land afternoon convective locations, the GEO derived SW fluxes will capture the diurnal flux not observed with Terra or Aqua sun-synchronous satellites. Obtaining fluxes from geostationary satellite radiance is a multistep process. First, most GEO visible imagers lack calibration and must be calibrated to MODIS and VIIRS. Second, the GEO imager visible channel radiances are converted to broadband radiances using empirical and theoretical models. The lack of coincident, collocated, and co-angled GEO and CERES measurements makes building an empirical model difficult. The narrowband to broadband models are a function of surface and cloud conditions, which are difficult to identify due to the inconsistent cloud retrievals between the 16 GEO imagers used in the CERES record. Third, the GEO derived broadband radiances are passed through the CERES angular distribution model (ADM) to convert the radiances to fluxes. Lastly, the GEO derived broadband fluxes are normalized with CERES fluxes in order to preserve the CERES instrument calibration. Validation is performed by comparing the GEO converted fluxes against CERES observations using coincident and collocated data. This work will focus on the GEO visible radiance conversion, validation approach, and Edition4 improvements.
Retrieving SW fluxes from geostationary narrowband radiances for the NASA-CERES SYN1deg product
NASA Astrophysics Data System (ADS)
Wrenn, F. J., IV; Doelling, D. R.; Liang, L.
2017-12-01
The CERES mission was designed to measure the natural variability of the net TOA flux over long time scales relevant to climate monitoring. To achieve this goal, CERES provides the level-3 SSF1deg, SYN1deg, and EBAF monthly 1° by 1° regional TOA flux. The single satellite (Terra or Aqua) SSF1deg 24-hour shortwave flux is based on one daytime measurements and assumes constant meteorology to model the diurnal change in albedo. To accurately describe regions with a prominent diurnal signal, the SYN1deg Edition4 dataset employs hourly geostationary (GEO) measurements. This improves upon Edition3, which used 3-hourly GEO measurements and with temporal interpolation. The EBAF product combines the temporal stability of the SSF1deg product with the diurnal information from SYN1deg and removes the CERES instrument calibration bias by constraining the net flux balance to the ocean heat storage term. The SYN-1deg product retrieves hourly SW fluxes from GEO measurements. Over regions with large diurnal cycles, such as maritime stratus and land afternoon convective locations, the GEO derived SW fluxes will capture the diurnal flux not observed with Terra or Aqua sun-synchronous satellites. Obtaining fluxes from geostationary satellite radiance is a multistep process. First, most GEO visible imagers lack calibration and must be calibrated to MODIS and VIIRS. Second, the GEO imager visible channel radiances are converted to broadband radiances using empirical and theoretical models. The lack of coincident, collocated, and co-angled GEO and CERES measurements makes building an empirical model difficult. The narrowband to broadband models are a function of surface and cloud conditions, which are difficult to identify due to the inconsistent cloud retrievals between the 16 GEO imagers used in the CERES record. Third, the GEO derived broadband radiances are passed through the CERES angular distribution model (ADM) to convert the radiances to fluxes. Lastly, the GEO derived broadband fluxes are normalized with CERES fluxes in order to preserve the CERES instrument calibration. Validation is performed by comparing the GEO converted fluxes against CERES observations using coincident and collocated data. This work will focus on the GEO visible radiance conversion, validation approach, and Edition4 improvements.
NASA Technical Reports Server (NTRS)
Lin, Xin; Zhang, Sara Q.; Hou, Arthur Y.
2006-01-01
Global microwave rainfall retrievals from a 5-satellite constellation, including TMI from TRMM, SSWI from DMSP F13, F14 and F15, and AMSR-E from EOS-AQUA, are assimilated into the NASA Goddard Earth Observing System (GEOS) Data Assimilation System (DAS) using a 1-D variational continuous assimilation (VCA) algorithm. The physical and dynamical impact of rainfall assimilation on GEOS analyses and forecasts is examined at various temporal and spatial scales. This study demonstrates that the 1-D VCA algorithm, which was originally developed and evaluated for rainfall assimilations over tropical oceans, can effectively assimilate satellite microwave rainfall retrievals and improve GEOS analyses over both the Tropics and the extratropics where the atmospheric processes are dominated by different large-scale dynamics and moist physics, and also over the land, where rainfall estimates from passive microwave radiometers are believed to be less accurate. Results show that rainfall assimilation renders the GEOS analysis physically and dynamically more consistent with the observed precipitation at the monthly-mean and 6-hour time scales. Over regions where the model precipitation tends to misbehave in distinctly different rainy regimes, the 1-D VCA algorithm, by compensating for errors in the model s moist time-tendency in a 6-h analysis window, is able to bring the rainfall analysis closer to the observed. The radiation and cloud fields also tend to be in better agreement with independent satellite observations in the rainfall-assimilation m especially over regions where rainfall analyses indicate large improvements. Assimilation experiments with and without rainfall data for a midlatitude frontal system clearly indicates that the GEOS analysis is improved through changes in the thermodynamic and dynamic fields that respond to the rainfall assimilation. The synoptic structures of temperature, moisture, winds, divergence, and vertical motion, as well as vorticity are more realistically captured across the front. Short-term forecasts using initial conditions assimilated with rainfall data also show slight improvements. 1
Borcherdt, Rodger D.; Johnston, Malcolm J.S.; Dietel, Christopher; Glassmoyer, Gary; Myren, Doug; Stephens, Christopher
2004-01-01
An integrated array of 11 General Earthquake Observation System (GEOS) stations installed near Parkfield, CA provided on scale broad-band, wide-dynamic measurements of acceleration and volumetric strain of the Parkfield earthquake (M 6.0) of September 28, 2004. Three component measurements of acceleration were obtained at each of the stations. Measurements of collocated acceleration and volumetric strain were obtained at four of the stations. Measurements of velocity at most sites were on scale only for the initial P-wave arrival. When considered in the context of the extensive set of strong-motion recordings obtained on more than 40 analog stations by the California Strong-Motion Instrumentation Program (Shakal, et al., 2004 http://www.quake.ca.gov/cisn-edc) and those on the dense array of Spudich, et al, (1988), these recordings provide an unprecedented document of the nature of the near source strong motion generated by a M 6.0 earthquake. The data set reported herein provides the most extensive set of near field broad band wide dynamic range measurements of acceleration and volumetric strain for an earthquake as large as M 6 of which the authors are aware. As a result considerable interest has been expressed in these data. This report is intended to describe the data and facilitate its use to resolve a number of scientific and engineering questions concerning earthquake rupture processes and resultant near field motions and strains. This report provides a description of the array, its scientific objectives and the strong-motion recordings obtained of the main shock. The report provides copies of the uncorrected and corrected data. Copies of the inferred velocities, displacements, and Psuedo velocity response spectra are provided. Digital versions of these recordings are accessible with information available through the internet at several locations: the National Strong-Motion Program web site (http://agram.wr.usgs.gov/), the COSMOS Virtual Data Center Web site (http://www.cosmos-eq.org), and the CISN Engineering and Berkeley data centers (http://www.quake.ca.gov/cisn-edc). They are also accessible together with recordings on the GEOS Strong-motion Array near Parkfield, CA since its installation in 1987 through the USGS GEOS web site ( http://nsmp.wr.usgs.gov/GEOS).
Feasibility of performing space surveillance tasks with a proposed space-based optical architecture
NASA Astrophysics Data System (ADS)
Flohrer, Tim; Krag, Holger; Klinkrad, Heiner; Schildknecht, Thomas
Under ESA contract an industrial consortium including Aboa Space Research Oy (ASRO), the Astronomical Institute of the University of Bern (AIUB), and the Dutch National Aerospace Laboratory (NLR), proposed the observation concept, developed a suitable sensor architecture, and assessed the performance of a space-based optical (SBO) telescope in 2005. The goal of the SBO instrumentation was to analyse how the existing knowledge gap in the space debris population in the millimetre and centimetre regime may be closed by means of a passive op-tical instrument. SBO was requested to provide statistical information on the space debris population, in terms of number of objects and size distribution. The SBO was considered to be a cost-efficient instrumentation of 20 cm aperture and 6 deg field-of-view with flexible integration requirements. It should be possible to integrate the SBO easily as a secondary payload on satellites launched into low-Earth orbits (LEO), or into geostationary orbit (GEO). Thus the selected mission concept only allowed for fix-mounted telescopes, and the pointing direction could be requested freely. It was shown in the performance analysis that the statistical information on small-sized space debris can only be collected if the observation ranges are comparatively small. Two of the most promising concepts were to observe objects in LEO from a sensor placed into a sun-synchronous LEO, while objects in GEO should be observed from a GEO satellite. Since 2007 ESA focuses space surveillance and tracking activities in the Space Situational Awareness (SSA) preparatory program. Ground-based radars and optical telescopes are stud-ied for the build-up and to maintenance of a catalogue of objects. In this paper we analyse how the SBO architecture could contribute to the space surveillance tasks survey and tracking. We assume that the SBO instrumentation is placed into a circular sun-synchronous orbit at 800 km altitude. We discuss the observation conditions of objects at higher altitude, such as GEO and Medium-Earth Orbits (MEO). Of particular interest are the radiometric performance from which we derive the detectable object diameters, the coverage of a reference population, and the covered arc lengths of individual objects. The latter is of particular interest for the simu-lation of the orbit determination, correlation, and cataloguing. Assuming realistic noise levels known from the SBO design we simulate first orbit determination of unknown objects (surveys) and orbit improvements (tracking) for sample objects. We use a simulation environment that comprises the ESA Program for Radar and Optical Observation Forecasting (PROOF) in the version 2005 and AIUB's program system CelMech. ESA's MASTER-2005 serves as reference population for all analyses.
Study of mobile satellite network based on GEO/LEO satellite constellation
NASA Astrophysics Data System (ADS)
Hu, Xiulin; Zeng, Yujiang; Wang, Ying; Wang, Xianhui
2005-11-01
Mobile satellite network with Inter Satellite Links (ISLs), which consists of non-geostationary satellites, has the characteristic of network topology's variability. This is a great challenge to the design and management of mobile satellite network. This paper analyzes the characteristics of mobile satellite network, takes multimedia Quality of Service (QoS) as the chief object and presents a reference model based on Geostationary Earth Orbit (GEO)/ Low Earth Orbit (LEO) satellite constellation which adapts to the design and management of mobile satellite network. In the reference model, LEO satellites constitute service subnet with responsibility for the access, transmission and switch of the multimedia services for mobile users, while GEO satellites constitute management subnet taking on the centralized management to service subnet. Additionally ground control centre realizes the whole monitoring and control via management subnet. Comparing with terrestrial network, the above reference model physically separates management subnet from service subnet, which not only enhances the advantage of centralized management but also overcomes the shortcoming of low reliability in terrestrial network. Routing of mobile satellite network based on GEO/LEO satellite constellation is also discussed in this paper.
GeoLab: A Geological Workstation for Future Missions
NASA Technical Reports Server (NTRS)
Evans, Cynthia; Calaway, Michael; Bell, Mary Sue; Li, Zheng; Tong, Shuo; Zhong, Ye; Dahiwala, Ravi
2014-01-01
The GeoLab glovebox was, until November 2012, fully integrated into NASA's Deep Space Habitat (DSH) Analog Testbed. The conceptual design for GeoLab came from several sources, including current research instruments (Microgravity Science Glovebox) used on the International Space Station, existing Astromaterials Curation Laboratory hardware and clean room procedures, and mission scenarios developed for earlier programs. GeoLab allowed NASA scientists to test science operations related to contained sample examination during simulated exploration missions. The team demonstrated science operations that enhance theThe GeoLab glovebox was, until November 2012, fully integrated into NASA's Deep Space Habitat (DSH) Analog Testbed. The conceptual design for GeoLab came from several sources, including current research instruments (Microgravity Science Glovebox) used on the International Space Station, existing Astromaterials Curation Laboratory hardware and clean room procedures, and mission scenarios developed for earlier programs. GeoLab allowed NASA scientists to test science operations related to contained sample examination during simulated exploration missions. The team demonstrated science operations that enhance the early scientific returns from future missions and ensure that the best samples are selected for Earth return. The facility was also designed to foster the development of instrument technology. Since 2009, when GeoLab design and construction began, the GeoLab team [a group of scientists from the Astromaterials Acquisition and Curation Office within the Astromaterials Research and Exploration Science (ARES) Directorate at JSC] has progressively developed and reconfigured the GeoLab hardware and software interfaces and developed test objectives, which were to 1) determine requirements and strategies for sample handling and prioritization for geological operations on other planetary surfaces, 2) assess the scientific contribution of selective in-situ sample characterization for mission planning, operations, and sample prioritization, 3) evaluate analytical instruments and tools for providing efficient and meaningful data in advance of sample return and 4) identify science operations that leverage human presence with robotic tools. In the first year of tests (2010), GeoLab examined basic glovebox operations performed by one and two crewmembers and science operations performed by a remote science team. The 2010 tests also examined the efficacy of basic sample characterization [descriptions, microscopic imagery, X-ray fluorescence (XRF) analyses] and feedback to the science team. In year 2 (2011), the GeoLab team tested enhanced software and interfaces for the crew and science team (including Web-based and mobile device displays) and demonstrated laboratory configurability with a new diagnostic instrument (the Multispectral Microscopic Imager from the JPL and Arizona State University). In year 3 (2012), the GeoLab team installed and tested a robotic sample manipulator and evaluated robotic-human interfaces for science operations.
The GMAO Hybrid Ensemble-Variational Atmospheric Data Assimilation System: Version 2.0
NASA Technical Reports Server (NTRS)
Todling, Ricardo; El Akkraoui, Amal
2018-01-01
This document describes the implementation and usage of the Goddard Earth Observing System (GEOS) Hybrid Ensemble-Variational Atmospheric Data Assimilation System (Hybrid EVADAS). Its aim is to provide comprehensive guidance to users of GEOS ADAS interested in experimenting with its hybrid functionalities. The document is also aimed at providing a short summary of the state-of-science in this release of the hybrid system. As explained here, the ensemble data assimilation system (EnADAS) mechanism added to GEOS ADAS to enable hybrid data assimilation applications has been introduced to the pre-existing machinery of GEOS in the most non-intrusive possible way. Only very minor changes have been made to the original scripts controlling GEOS ADAS with the objective of facilitating its usage by both researchers and the GMAO's near-real-time Forward Processing applications. In a hybrid scenario two data assimilation systems run concurrently in a two-way feedback mode such that: the ensemble provides background ensemble perturbations required by the ADAS deterministic (typically high resolution) hybrid analysis; and the deterministic ADAS provides analysis information for recentering of the EnADAS analyses and information necessary to ensure that observation bias correction procedures are consistent between both the deterministic ADAS and the EnADAS. The nonintrusive approach to introducing hybrid capability to GEOS ADAS means, in particular, that previously existing features continue to be available. Thus, not only is this upgraded version of GEOS ADAS capable of supporting new applications such as Hybrid 3D-Var, 3D-EnVar, 4D-EnVar and Hybrid 4D-EnVar, it remains possible to use GEOS ADAS in its traditional 3D-Var mode which has been used in both MERRA and MERRA-2. Furthermore, as described in this document, GEOS ADAS also supports a configuration for exercising a purely ensemble-based assimilation strategy which can be fully decoupled from its variational component. We should point out that Release 1.0 of this document was made available to GMAO in mid-2013, when we introduced Hybrid 3D-Var capability to GEOS ADAS. This initial version of the documentation included a considerably different state-of-science introductory section but many of the same detailed description of the mechanisms of GEOS EnADAS. We are glad to report that a few of the desirable Future Works listed in Release 1.0 have now been added to the present version of GEOS EnADAS. These include the ability to exercise an Ensemble Prediction System that uses the ensemble analyses of GEOS EnADAS and (a very early, but functional version of) a tool to support Ensemble Forecast Sensitivity and Observation Impact applications.
NASA Technical Reports Server (NTRS)
Rodriquez-Cowardin, H.; Abercromby, K.; Barker, E.; Mulrooney, M.; Seitzer, P.; Schildknecht, T.
2009-01-01
Optical observations of orbital debris offer insights that differ from radar measurements (specifically the size parameter and wavelength regime). For example, time-dependent photometric data yield lightcurves in multiple bandpasses that aid in material identification and possible periodic orientations. This data can also be used to help identify shapes and optical properties at multiple phase angles. Capitalizing on optical data products and applying them to generate a more complete understanding of orbital space objects, is a key objective of NASA s Optical Measurement Program, and a primary driver for creation of the Optical Measurements Center (OMC). The OMC attempts to emulate space-based illumination conditions using equipment and techniques that parallel telescopic observations and source-target-sensor orientations. The OMC uses a 300 Watt Xenon arc lamp as a solar simulator, a CCD camera with Johnson/Bessel colored filters, and a robotic arm to orientate/rotate objects to simulate an object's orbit/rotational period. A high-resolution, high bandwidth (350nm-2500nm) Analytical Spectral Devices (ASD) spectrometer is also employed to baseline various material types. Since observation of GEO targets are generally restricted to the optical regime (due to radar range limitations), analysis of their properties is tailored to those revealed by optical data products. In this connection, much attention has been directed towards understanding the lightcurves of orbital debris with high area-to-mass (A/m) ratios (greater than 0.9 square meters per kilogram). A small population of GEO debris was recently identified, which exhibits the properties of high A/m objects, such as variable eccentricities and inclinations a dynamical characteristic generally resulting from varying solar radiation pressure on high A/m objects. Materials such as multi-layered insulation (MLI) and solar panels are two examples of materials with high area-to mass ratios. Lightcurves for such objects can vary greatly (even for the same object under different illumination conditions). For example, specular reflections from multiple facets of the target surface (e.g. Mylar or Aluminized Kapton) can lead to erratic, orientation-dependent light curves. This paper will investigate published color photometric data for a series of orbital debris targets and compare it to the empirical photometric measurements generated in the OMC. The specific materials investigated (known to exist in GEO) are: an intact piece of MLI, separated layers of MLI, and multiple solar cells materials. Using the data acquired over specific rotational angles through different filters (B, V, R, I), a color index is acquired (B-R, R-I). As a secondary check, the spectrometer is used to define color indexes for the same material. Using these values and their associated lightcurves, this laboratory data is compared to observational data obtained on the 1m telescope of the Astronomical Institute of the University of Bern (AUIB) and the 0.9 m Small and Moderate Aperture Research Telescope System (SMARTS) telescope at Cerro Tololo Inter-American Observatory (CTIO). We will present laboratory generated lightcurves with color indexes of the high A/m materials alongside telescopic data of targets with high A/m values. We will discuss the relationship of laboratory to telescope data in the context of classification of GEO debris objects.
Bousserez, Nicolas; Henze, Daven K.; Rooney, Brigitte; ...
2016-05-20
The success of future geostationary (GEO) satellite observation missions depends on our ability to design instruments that address their key scientific objectives. Here, an Observation System Simulation Experiment (OSSE) is performed to quantify the constraints on methane (CH 4) emissions in North America obtained from shortwave infrared (SWIR), thermal infrared (TIR), and multi-spectral (SWIR+TIR) measurements in geostationary orbit and from future SWIR low-Earth orbit (LEO) measurements. Furthermore, we used an efficient stochastic algorithm to compute the information content of the inverted emissions at high spatial resolution (0.5° × 0.7°) in a variational framework using the GEOS-Chem chemistry-transport model and itsmore » adjoint. Our results show that at sub-weekly timescales, SWIR measurements in GEO orbit can constrain about twice as many independent flux patterns than in LEO orbit, with a degree of freedom for signal (DOF) for the inversion of 266 and 115, respectively. Comparisons between TIR GEO and SWIR LEO configurations reveal that poor boundary layer sensitivities for the TIR measurements cannot be compensated for by the high spatiotemporal sampling of a GEO orbit. The benefit of a multi-spectral instrument compared to current SWIR products in a GEO context is shown for sub-weekly timescale constraints, with an increase in the DOF of about 50 % for a 3-day inversion. Our results further suggest that both the SWIR and multi-spectral measurements on GEO orbits could almost fully resolve CH 4 fluxes at a spatial resolution of at least 100 km × 100 km over source hotspots (emissions > 4 × 10 5 kg day -1). The sensitivity of the optimized emission scaling factors to typical errors in boundary and initial conditions can reach 30 and 50 % for the SWIR GEO or SWIR LEO configurations, respectively, while it is smaller than 5 % in the case of a multi-spectral GEO system. Our results demonstrate that multi-spectral measurements from a geostationary satellite platform would address the need for higher spatiotemporal constraints on CH 4 emissions while greatly mitigating the impact of inherent uncertainties in source inversion methods on the inferred fluxes.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bousserez, Nicolas; Henze, Daven K.; Rooney, Brigitte
The success of future geostationary (GEO) satellite observation missions depends on our ability to design instruments that address their key scientific objectives. Here, an Observation System Simulation Experiment (OSSE) is performed to quantify the constraints on methane (CH 4) emissions in North America obtained from shortwave infrared (SWIR), thermal infrared (TIR), and multi-spectral (SWIR+TIR) measurements in geostationary orbit and from future SWIR low-Earth orbit (LEO) measurements. Furthermore, we used an efficient stochastic algorithm to compute the information content of the inverted emissions at high spatial resolution (0.5° × 0.7°) in a variational framework using the GEOS-Chem chemistry-transport model and itsmore » adjoint. Our results show that at sub-weekly timescales, SWIR measurements in GEO orbit can constrain about twice as many independent flux patterns than in LEO orbit, with a degree of freedom for signal (DOF) for the inversion of 266 and 115, respectively. Comparisons between TIR GEO and SWIR LEO configurations reveal that poor boundary layer sensitivities for the TIR measurements cannot be compensated for by the high spatiotemporal sampling of a GEO orbit. The benefit of a multi-spectral instrument compared to current SWIR products in a GEO context is shown for sub-weekly timescale constraints, with an increase in the DOF of about 50 % for a 3-day inversion. Our results further suggest that both the SWIR and multi-spectral measurements on GEO orbits could almost fully resolve CH 4 fluxes at a spatial resolution of at least 100 km × 100 km over source hotspots (emissions > 4 × 10 5 kg day -1). The sensitivity of the optimized emission scaling factors to typical errors in boundary and initial conditions can reach 30 and 50 % for the SWIR GEO or SWIR LEO configurations, respectively, while it is smaller than 5 % in the case of a multi-spectral GEO system. Our results demonstrate that multi-spectral measurements from a geostationary satellite platform would address the need for higher spatiotemporal constraints on CH 4 emissions while greatly mitigating the impact of inherent uncertainties in source inversion methods on the inferred fluxes.« less
A Search for Optically Faint GEO Debris
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Lederer, Susan M.; Barker, Edwin S.; Cowardin, Heather; Abercromby, Kira J.; ilha, Jiri
2011-01-01
Existing optical surveys for debris at geosynchronous orbit (GEO) have been conducted with meter class telescopes, which have detection limits in the range of 18th-19th magnitude. We report on a new search for optically faint debris at GEO using the 6.5-m Magellan 1 telescope Walter Baade at Las Campanas Observatory in Chile. Our goal is to go as faint as possible and characterize the brightness distribution of debris fainter than R = 20th magnitude, corresponding to a size smaller than 10 cm assuming an albedo of 0.175. We wish to compare the inferred size distribution for GEO debris with that for LEO debris. We describe results obtained during 9.4 hours of observing time during 25-27 March 2011. We used the IMACS f/2 instrument, which has a mosaic of 8 CCDs, and a field of view of 30 arc-minutes in diameter. This is the widest field of view of any instrument on either Magellan telescope. All observations were obtained through a Sloan r filter. The limiting magnitude for 5 second exposures is estimated to be fainter than 22. With this small field of view and the limited observing time, our objective was to search for optically faint objects from the Titan 3C Transtage (1968-081) fragmentation in 1992. Eight debris pieces and the parent rocket body are in the Space Surveillance Network public catalog. We successfully tracked two cataloged pieces of Titan debris (SSN # 25001 and 33519) with the 6.5-m telescope, followed by a survey for objects on similar orbits but with a spread in mean anomaly. To detect bright objects over a wider field of view (1.6x1.6 degrees), we observed the same field centers at the same time through a similar filter with the 0.6-m MODEST (Michigan Orbital DEbris Survey Telescope), located 100 km to the south of Magellan at Cerro Tololo Inter-American Observatory, Chile. We will describe our experiences using Magellan, a telescope never used previously for orbital debris research, and our initial results.
NASA Astrophysics Data System (ADS)
Lederer, S.; Cowardin, H.; Buckalew, B.; Frith, J.; Hickson, P.; Pace, L.; Matney, M.; Anz-Meador, P.; Seitzer, P.; Stansbery, E.; Glesne, T.
2016-09-01
Characterizing debris in Earth-orbit has become increasingly important as the growing population of debris poses greater threats to active satellites each year. Currently, the Joint Space Operations is tracking > 23,000 objects ranging in size from 1-meter and larger in Geosychronous orbits (GEO) to 10-cm and larger at low-Earth orbits (LEO). Model estimates suggest that there are hundreds of thousands of pieces of spacecraft debris larger than 10 cm currently in orbit around the Earth. With such a small fraction of the total population being tracked, and new break-ups occurring from LEO to GEO, new assets, techniques, and approaches for characterizing this debris are needed. With this in mind, NASA's Orbital Debris Program Office has actively tasked a suite of telescopes around the world. In 2015, the newly-built 1.3m optical Meter Class Autonomous Telescope (MCAT) came on-line on Ascension Island and is now being commissioned. MCAT is designed to track Earth-orbiting objects above 200km, conduct surveys at GEO, and work with a co-located Raven-class commercial-off-the-shelf system, a 0.4m telescope with a field-of-view similar to MCAT's and research-grade instrumentation designed to complement MCAT. The 3.8m infrared UKIRT telescope on Mauna Kea, Hawaii has been heavily tasked to collect data on individual targets and in survey modes to study both the general GEO population and a break-up event. Data collected include photometry and spectroscopy in the near-Infrared (0.85 - 2.5μm) and the mid-infrared (8-16μm). Finally, the 6.5-m Baade Magellan telescope at Las Campanas Observatory in Chile was used to collect optical photometric survey data in October 2015 of two GEO Titan transtage breakups, focusing on locations of possible debris concentrations as indicated by the NASA standard break-up model.
NASA Astrophysics Data System (ADS)
Cahyanti, Pita A. B.; Agus, Cahyono
2017-08-01
Karst areas in Indonesia amounted to 154,000 km2, potentially for extractive cement and wall paint industries. Exploitation of karst caused serious problems on the environment, health and social culture of the local community. Even though, karst region as a natural and cultural world heritage also have potential environmental services such as water resources, carbon sink, biodiversity, unique landscapes, natural caves, natural attractions, archaeological sites and mystic areas. Landscape architectural management of in the concept of blue revolution through the empowerment of land resources (soil, water, minerals) and biological resources (plant, animal, human), not only have adding value of economy aspect but also our dignified and sustainable environment and life through health, environmental, social, cultural, technological and management aspects. Geo-eco-tourism offers the efficiency of investment, increased creative innovation, increased funding, job creation, social capital development, stimulation of the socio-entrepreneurship in community. Community based geo-eco-tourism in Gunung Kidul Yogyakarta rapidly growing lately due to the local government banned the exploitation of karst. Landscape architecture at the caves, white sand beaches, cliffs in karst areas that beautiful, artistic and have special rare natural architecture form of stalactite and stalagmite, become the new phenomenal interested object of geo-eco-tourism. Many hidden nature objects that had been deserted and creepy could be visited by many local and foreign tourists. Landscape architectural management on hilltops with a wide view of the universe and fresh, sunset and sunrise, the clouds country are a rare sight for modern community. Local cultural attractions, local culinary, home stay with local communities will be an added attraction, but the infrastructure and human resources should be developed. Traveler photographs that widespread rapidly through social media and mass media became a great and effective promotion. With geo-eco-tourism, people can empowering natural resource to gain harmonization of economic, environment and social-culture aspect, without destroy it.
NASA Astrophysics Data System (ADS)
Huang, L.; Zhu, X.; Guo, W.; Xiang, L.; Chen, X.; Mei, Y.
2012-07-01
Existing implementations of collaborative image interpretation have many limitations for very large satellite imageries, such as inefficient browsing, slow transmission, etc. This article presents a KML-based approach to support distributed, real-time, synchronous collaborative interpretation for remote sensing images in the geo-browser. As an OGC standard, KML (Keyhole Markup Language) has the advantage of organizing various types of geospatial data (including image, annotation, geometry, etc.) in the geo-browser. Existing KML elements can be used to describe simple interpretation results indicated by vector symbols. To enlarge its application, this article expands KML elements to describe some complex image processing operations, including band combination, grey transformation, geometric correction, etc. Improved KML is employed to describe and share interpretation operations and results among interpreters. Further, this article develops some collaboration related services that are collaboration launch service, perceiving service and communication service. The launch service creates a collaborative interpretation task and provides a unified interface for all participants. The perceiving service supports interpreters to share collaboration awareness. Communication service provides interpreters with written words communication. Finally, the GeoGlobe geo-browser (an extensible and flexible geospatial platform developed in LIESMARS) is selected to perform experiments of collaborative image interpretation. The geo-browser, which manage and visualize massive geospatial information, can provide distributed users with quick browsing and transmission. Meanwhile in the geo-browser, GIS data (for example DEM, DTM, thematic map and etc.) can be integrated to assist in improving accuracy of interpretation. Results show that the proposed method is available to support distributed collaborative interpretation of remote sensing image
A Technical Survey on Optimization of Processing Geo Distributed Data
NASA Astrophysics Data System (ADS)
Naga Malleswari, T. Y. J.; Ushasukhanya, S.; Nithyakalyani, A.; Girija, S.
2018-04-01
With growing cloud services and technology, there is growth in some geographically distributed data centers to store large amounts of data. Analysis of geo-distributed data is required in various services for data processing, storage of essential information, etc., processing this geo-distributed data and performing analytics on this data is a challenging task. The distributed data processing is accompanied by issues in storage, computation and communication. The key issues to be dealt with are time efficiency, cost minimization, utility maximization. This paper describes various optimization methods like end-to-end multiphase, G-MR, etc., using the techniques like Map-Reduce, CDS (Community Detection based Scheduling), ROUT, Workload-Aware Scheduling, SAGE, AMP (Ant Colony Optimization) to handle these issues. In this paper various optimization methods and techniques used are analyzed. It has been observed that end-to end multiphase achieves time efficiency; Cost minimization concentrates to achieve Quality of Service, Computation and reduction of Communication cost. SAGE achieves performance improvisation in processing geo-distributed data sets.
NASA Technical Reports Server (NTRS)
Bernstein, W.
1981-01-01
The possible use of Chamber A for the replication or simulation of space plasma physics processes which occur in the geosynchronous Earth orbit (GEO) environment is considered. It is shown that replication is not possible and that scaling of the environmental conditions is required for study of the important instability processes. Rules for such experimental scaling are given. At the present time, it does not appear technologically feasible to satisfy these requirements in Chamber A. It is, however, possible to study and qualitatively evaluate the problem of vehicle charging at GEO. In particular, Chamber A is sufficiently large that a complete operational spacecraft could be irradiated by beams and charged to high potentials. Such testing would contribute to the assessment of the operational malfunctions expected at GEO and their possible correction. However, because of the many tabulated limitations in such a testing programs, its direct relevance to conditions expected in the geo environment remains questionable.
NASA Astrophysics Data System (ADS)
Cegarra Polo, M.; Alenin, A.; Vaughn, I.; Lambert, A.
2016-09-01
Polarimetry has shown capacity for both geometry inference and material classification in recent years. By carefully selecting a polarimetric modality with higher contrast for the objects of interest, it becomes possible to discriminate those objects by leveraging the understanding of differing geometry, material characteristics, and its mapping into consequent polarisation measurements. Expansion of the measurement dimensionality increases the potential to discriminate unresolved objects, thereby widening the possible set of imaging tasks. The use of polarimetry as a technique to characterise non-resolved GEO satellites using telescopes of small aperture (less than 0.5 meters) is currently under study by the Space Research Group in UNSW Canberra. First experiments are currently being performed in order to evaluate the use of this technique to characterise GEO satellites. A comparison of both polarimetric and irradiance only acquisitions is being implemented. Two telescopes separated by 1000m are used for the experiments. One of them (USAFA funded Falcon Telescope Network) has the capability to be remote controlled and time tasks assigned, and the other can be operated on-site and is connected to a computer in a network which can control the former with known latency, both synchronised by the same GPS clock. A linear polariser is situated in a collimated beam section of the light path in one of the telescopes to capture polarised photometric measurements, while the other is acquiring the non-polarised photometric signature of the same GEO satellite under observation. The telescope detectors are to be radiometrically calibrated to one another in order to evaluate the photometric data at the same scale. We evaluate the polarised and non-polarised synchronous time photometric curves as a preliminary test to determine satellite signature and its variation over time. We report on the discrimination of unresolved satellites and the merit of including polarisation sensing within the task.
NASA Technical Reports Server (NTRS)
Kelecy, Tom; Payne, Tim; Thurston, Robin; Stansbery, Gene
2007-01-01
A population of deep space objects is thought to be high area-to-mass ratio (AMR) debris having origins from sources in the geosynchronous orbit (GEO) belt. The typical AMR values have been observed to range anywhere from 1's to 10's of m(sup 2)/kg, and hence, higher than average solar radiation pressure effects result in long-term migration of eccentricity (0.1-0.6) and inclination over time. However, the nature of the debris orientation-dependent dynamics also results time-varying solar radiation forces about the average which complicate the short-term orbit determination processing. The orbit determination results are presented for several of these debris objects, and highlight their unique and varied dynamic attributes. Estimation or the solar pressure dynamics over time scales suitable for resolving the shorter term dynamics improves the orbit estimation, and hence, the orbit predictions needed to conduct follow-up observations.
Gravity model improvement investigation. [improved gravity model for determination of ocean geoid
NASA Technical Reports Server (NTRS)
Siry, J. W.; Kahn, W. D.; Bryan, J. W.; Vonbun, F. F.
1973-01-01
This investigation was undertaken to improve the gravity model and hence the ocean geoid. A specific objective is the determination of the gravity field and geoid with a space resolution of approximately 5 deg and a height resolution of the order of five meters. The concept of the investigation is to utilize both GEOS-C altimeter and satellite-to-satellite tracking data to achieve the gravity model improvement. It is also planned to determine the geoid in selected regions with a space resolution of about a degree and a height resolution of the order of a meter or two. The short term objectives include the study of the gravity field in the GEOS-C calibration area outlined by Goddard, Bermuda, Antigua, and Cape Kennedy, and also in the eastern Pacific area which is viewed by ATS-F.
Profiling and Improving I/O Performance of a Large-Scale Climate Scientific Application
NASA Technical Reports Server (NTRS)
Liu, Zhuo; Wang, Bin; Wang, Teng; Tian, Yuan; Xu, Cong; Wang, Yandong; Yu, Weikuan; Cruz, Carlos A.; Zhou, Shujia; Clune, Tom;
2013-01-01
Exascale computing systems are soon to emerge, which will pose great challenges on the huge gap between computing and I/O performance. Many large-scale scientific applications play an important role in our daily life. The huge amounts of data generated by such applications require highly parallel and efficient I/O management policies. In this paper, we adopt a mission-critical scientific application, GEOS-5, as a case to profile and analyze the communication and I/O issues that are preventing applications from fully utilizing the underlying parallel storage systems. Through in-detail architectural and experimental characterization, we observe that current legacy I/O schemes incur significant network communication overheads and are unable to fully parallelize the data access, thus degrading applications' I/O performance and scalability. To address these inefficiencies, we redesign its I/O framework along with a set of parallel I/O techniques to achieve high scalability and performance. Evaluation results on the NASA discover cluster show that our optimization of GEOS-5 with ADIOS has led to significant performance improvements compared to the original GEOS-5 implementation.
Coordinated Field Campaigns in Chesapeake Bay and Gulf of Mexico
NASA Technical Reports Server (NTRS)
Mannino, Antonio; Novak, Michael; Tzortziou, Maria A.
2015-01-01
NASA's GEOstationary Coastal and Air Pollution Events (GEO-CAPE) mission concept recommended by the U.S. National Research Council (2007) focuses on measurements of atmospheric trace gases and aerosols and aquatic coastal ecology and biogeochemistry from geostationary orbit (35,786 km altitude). Two GEO-CAPE-sponsored multi-investigator ship-based field campaigns were conducted to coincide with the NASA Earth Venture Suborbital project DISCOVER-AQ (Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality) field campaigns: (1) Chesapeake Bay in July 2011 and (2) northwestern Gulf of Mexico in September 2013. Goal: to evaluate whether GEO-CAPE coastal mission measurement and instrument requirements are optimized to address science objectives while minimizing ocean color satellite sensor complexity, size and cost - critical mission risk reduction activities. NASA continues to support science studies related to the analysis of data collected as part of these coordinated field campaigns and smaller efforts.
Non-methane volatile organic compounds in Africa: A view from space
NASA Astrophysics Data System (ADS)
Marais, Eloise Ann
Isoprene emissions affect human health, air quality, and the oxidative capacity of the atmosphere. Globally anthropogenic non-methane volatile organic compounds (NMVOC) emissions are lower than that of isoprene, but local hotspots are hazardous to human health and air quality. In Africa the tropics are a large source of isoprene, while Nigeria appears as a large contributor to regional anthropogenic NMVOC emissions. I make extensive use of space-based formaldehyde (HCHO) observations from the Ozone Monitoring Instrument (OMI) and the chemical transport model (CTM) GEOS-Chem to estimate and examine seasonality of isoprene emissions across Africa, and identify sources and air quality consequences of anthropogenic NMVOC emissions in Nigeria. To estimate isoprene emissions I first developed a filtering scheme to remove (1) contamination from biomass burning and anthropogenic influences; and (2) displacement of HCHO from the isoprene emission source diagnosed with the GEOS-Chem CTM. Conversion to isoprene emissions is with NOx-dependent GEOS-Chem HCHO yields, obtained as the local sensitivity S of the HCHO column ΩHCHO to a perturbation Delta in isoprene emissions EISOP (S = DeltaΩHCHO/DeltaE ISOP). The error in OMI-derived isoprene emissions is 40% at low levels of NOx and 40-90% under high-NOx conditions and is reduced by spatial and temporal averaging to the extent that errors are random. Weak isoprene emission seasonality in equatorial forests is driven predominantly by temperature, while large seasonality in northern and southern savannas is driven by temperature and leaf area index. The largest contribution of African isoprene emissions to surface ozone and particulate matter, determined with GEOS-Chem, of 8 ppbv and 1.5 μg m-3, respectively, is over West Africa. The OMI HCHO data feature a large enhancement over Nigeria that is due to anthropogenic NMVOC emissions. With the OMI HCHO data, coincident satellite observations of atmospheric composition, aircraft measurements, and GEOS-Chem I estimate Nigerian NMVOC emissions that are higher per capita than China (5.7 Tg C a-1). Should Nigeria develop its electricity sector to sustain economic growth with local natural gas and coal reserves NO x emissions will exacerbate wintertime (December-February) surface ozone pollution that exceeds 90 ppbv due to poor ventilation and the Harmattan inversion layer.
Development of an Electrostatically Clean Solar Array Panel
NASA Technical Reports Server (NTRS)
Stern, Theodore G.; Krumweide, Duane; Gaddy, Edward; Katz, Ira
2000-01-01
The results of design, analysis, and qualification of an Electrostatically Clean Solar Array (ECSA) panel are described. The objective of the ECSA design is to provide an electrostatic environment that does not interfere with sensitive instruments on scientific spacecraft. The ECSA design uses large, ITO-coated coverglasses that cover multiple solar cells, an aperture grid that covers the intercell areas, stress-relieved interconnects for connecting the aperture grid to the coverglasses, and edge clips to provides an electromagnetically shielded enclosure for the solar array active circuitry. Qualification coupons were fabricated and tested for photovoltaic response, conductivity, and survivability to launch acoustic and thermal cycling environments simulating LEO and GEO missions. The benefits of reducing solar panel interaction with the space environment are also discussed.
Spacecraft-plasma interaction codes: NASCAP/GEO, NASCAP/LEO, POLAR, DynaPAC, and EPSAT
NASA Technical Reports Server (NTRS)
Mandell, M. J.; Jongeward, G. A.; Cooke, D. L.
1992-01-01
Development of a computer code to simulate interactions between the surfaces of a geometrically complex spacecraft and the space plasma environment involves: (1) defining the relevant physical phenomena and formulating them in appropriate levels of approximation; (2) defining a representation for the 3-D space external to the spacecraft and a means for defining the spacecraft surface geometry and embedding it in the surrounding space; (3) packaging the code so that it is easy and practical to use, interpret, and present the results; and (4) validating the code by continual comparison with theoretical models, ground test data, and spaceflight experiments. The physical content, geometrical capabilities, and application of five S-CUBED developed spacecraft plasma interaction codes are discussed. The NASA Charging Analyzer Program/geosynchronous earth orbit (NASCAP/GEO) is used to illustrate the role of electrostatic barrier formation in daylight spacecraft charging. NASCAP/low Earth orbit (LEO) applications to the CHARGE-2 and Space Power Experiment Aboard Rockets (SPEAR)-1 rocket payloads are shown. DynaPAC application to the SPEAR-2 rocket payloads is described. Environment Power System Analysis Tool (EPSAT) is illustrated by application to Tethered Satellite System 1 (TSS-1), SPEAR-3, and Sundance. A detailed description and application of the Potentials of Large Objects in the Auroral Region (POLAR) Code are presented.
Global 3-D Modeling Studies Of Tropospheric Ozone And Related Gases
NASA Technical Reports Server (NTRS)
Jacob, Daniel J.; Logan, Jennifer A.
2003-01-01
Our research was targeted at three issues: (1) the factors controlling ozone in the tropical troposphere, (2) the Asian outflow of ozone and its precursors, and (3) the causes of decadal trends observed in ozone and CO. We have also used support from this ACMAP grant to (1) work with Kelly Chance on the retrieval and interpretation of HCHO and NO2 observations from GOME, and (2) develop GEOS-CHEM into a versatile model supporting the work of a large number of users including outside Harvard. ACMAP has provided the core support for GEOS-CHEM development. Applications of the GEOS-CHEM model with primary support from ACMAP are discussed below. A list of publications resulting from this grant is given at the end of the report.
Electric Propulsion Performance from Geo-transfer to Geosynchronous Orbits
NASA Technical Reports Server (NTRS)
Dankanich, John W.; Carpenter, Christian B.
2007-01-01
For near-Earth application, solar electric propulsion advocates have focused on Low Earth Orbit (LEO) to Geosynchronous (GEO) low-thrust transfers because of the significant improvement in capability over chemical alternatives. While the performance gain attained from starting with a lower orbit is large, there are also increased transfer times and radiation exposure risk that has hindered the commercial advocacy for electric propulsion stages. An incremental step towards electric propulsion stages is the use of integrated solar electric propulsion systems (SEPS) for GTO to GEO transfer. Thorough analyses of electric propulsion systems options and performance are presented. Results are based on existing or near-term capabilities of Arcjets, Hall thrusters, and Gridded Ion engines. Parametric analyses based on "rubber" thruster and launch site metrics are also provided.
NASA Technical Reports Server (NTRS)
Larson, Jay W.
1998-01-01
Atmospheric data assimilation is a method of combining actual observations with model forecasts to produce a more accurate description of the earth system than the observations or forecast alone can provide. The output of data assimilation, sometimes called the analysis, are regular, gridded datasets of observed and unobserved variables. Analysis plays a key role in numerical weather prediction and is becoming increasingly important for climate research. These applications, and the need for timely validation of scientific enhancements to the data assimilation system pose computational demands that are best met by distributed parallel software. The mission of the NASA Data Assimilation Office (DAO) is to provide datasets for climate research and to support NASA satellite and aircraft missions. The system used to create these datasets is the Goddard Earth Observing System Data Assimilation System (GEOS DAS). The core components of the the GEOS DAS are: the GEOS General Circulation Model (GCM), the Physical-space Statistical Analysis System (PSAS), the Observer, the on-line Quality Control (QC) system, the Coupler (which feeds analysis increments back to the GCM), and an I/O package for processing the large amounts of data the system produces (which will be described in another presentation in this session). The discussion will center on the following issues: the computational complexity for the whole GEOS DAS, assessment of the performance of the individual elements of GEOS DAS, and parallelization strategy for some of the components of the system.
The Global Modeling and Assimilation Office (GMAO) 4d-Var and its Adjoint-based Tools
NASA Technical Reports Server (NTRS)
Todling, Ricardo; Tremolet, Yannick
2008-01-01
The fifth generation of the Goddard Earth Observing System (GEOS-5) Data Assimilation System (DAS) is a 3d-var system that uses the Grid-point Statistical Interpolation (GSI) system developed in collaboration with NCEP, and a general circulation model developed at Goddard, that includes the finite-volume hydrodynamics of GEOS-4 wrapped in the Earth System Modeling Framework and physical packages tuned to provide a reliable hydrological cycle for the integration of the Modern Era Retrospective-analysis for Research and Applications (MERRA). This MERRA system is essentially complete and the next generation GEOS is under intense development. A prototype next generation system is now complete and has been producing preliminary results. This prototype system replaces the GSI-based Incremental Analysis Update procedure with a GSI-based 4d-var which uses the adjoint of the finite-volume hydrodynamics of GEOS-4 together with a vertical diffusing scheme for simplified physics. As part of this development we have kept the GEOS-5 IAU procedure as an option and have added the capability to experiment with a First Guess at the Appropriate Time (FGAT) procedure, thus allowing for at least three modes of running the data assimilation experiments. The prototype system is a large extension of GEOS-5 as it also includes various adjoint-based tools, namely, a forecast sensitivity tool, a singular vector tool, and an observation impact tool, that combines the model sensitivity tool with a GSI-based adjoint tool. These features bring the global data assimilation effort at Goddard up to date with technologies used in data assimilation systems at major meteorological centers elsewhere. Various aspects of the next generation GEOS will be discussed during the presentation at the Workshop, and preliminary results will illustrate the discussion.
NASA Technical Reports Server (NTRS)
Selkirk, Henry B.; Manyin, M.; Ott, L.; Oman, L.; Benson, C.; Pawson, S.; Douglass, A. R.; Stolarski, R. S.
2011-01-01
The formation of contrails and contrail cirrus is very sensitive to the relative humidity of the upper troposphere. To reduce uncertainty in an estimate of the radiative impact of aviation-induced cirrus, a model must therefore be able to reproduce the observed background moisture fields with reasonable and quantifiable fidelity. Here we present an upper tropospheric moisture climatology from a 26-year ensemble of simulations using the GEOS CCM. We compare this free-running model's moisture fields to those obtained from the MLS and AIRS satellite instruments, our most comprehensive observational databases for upper tropospheric water vapor. Published comparisons have shown a substantial wet bias in GEOS-5 assimilated fields with respect to MLS water vapor and ice water content. This tendency is clear as well in the GEOS CCM simulations. The GEOS-5 moist physics in the GEOS CCM uses a saturation adjustment that prevents supersaturation, which is unrealistic when compared to in situ moisture observations from MOZAIC aircraft and balloon sondes as we will show. Further, the large-scale satellite datasets also consistently underestimate super-saturation when compared to the in-situ observations. We place these results in the context of estimates of contrail and contrail cirrus frequency.
Toward GEOS-6, A Global Cloud System Resolving Atmospheric Model
NASA Technical Reports Server (NTRS)
Putman, William M.
2010-01-01
NASA is committed to observing and understanding the weather and climate of our home planet through the use of multi-scale modeling systems and space-based observations. Global climate models have evolved to take advantage of the influx of multi- and many-core computing technologies and the availability of large clusters of multi-core microprocessors. GEOS-6 is a next-generation cloud system resolving atmospheric model that will place NASA at the forefront of scientific exploration of our atmosphere and climate. Model simulations with GEOS-6 will produce a realistic representation of our atmosphere on the scale of typical satellite observations, bringing a visual comprehension of model results to a new level among the climate enthusiasts. In preparation for GEOS-6, the agency's flagship Earth System Modeling Framework [JDl] has been enhanced to support cutting-edge high-resolution global climate and weather simulations. Improvements include a cubed-sphere grid that exposes parallelism; a non-hydrostatic finite volume dynamical core, and algorithm designed for co-processor technologies, among others. GEOS-6 represents a fundamental advancement in the capability of global Earth system models. The ability to directly compare global simulations at the resolution of spaceborne satellite images will lead to algorithm improvements and better utilization of space-based observations within the GOES data assimilation system
Photometric Studies of Rapidly Spinning Decommissioned GEO Satellites
NASA Astrophysics Data System (ADS)
Ryan, W.; Ryan, E.
A satellites general characteristics can be substantially influenced by changes in the space environment. Rapidly spinning decommissioned satellites provide an excellent opportunity to study the rotation-dependent physical processes that affect a resident space objects (RSO) spin kinematics over time. Specifically, inactive satellites at or near geosynchronous Earth-orbit (GEO) provide easy targets for which high quality data can be collected and analyzed such that small differences can be detected under single-year or less time frames. Previous workers have shown that the rotational periods of defunct GEOs have been changing over time [1]. Further, the Yarkovsky-OKeefe-Radzievskii-Paddak (YORP) effect, a phenomenon which has been well-studied in the context of the changing the spin states of asteroids, has recently been suggested to be the cause of secular alterations in the rotational period of inactive satellites [2]. Researchers at the Magdalena Ridge Observatory 2.4-meter telescope (operated by the New Mexico Institute of Mining and Technology) have been investigating the spins states of retired GEOs and other high altitude space debris since 2007 [3]. In this current work, the 2.4-meter telescope was used to track and observe the objects typically over a one- to two-hour period, repeated several times over the course of weeks. When feasible, this is then repeated on a yearly basis. Data is taken with a 1 second cadence, nominally in groups of three 600 second image sets. With the current equipment, the cadence of the image sequences is very precise while the start time is accurate only to the nearest second. Therefore, periods are determined individually using each image sequence. Repeatability of the period determination for each of these sequences is typically on the order of 0.01 second or better for objects where a single period is identified. Spin rate periods determined from the GEO light curves collected thus far have been found to range from ~3 sec to many tens of seconds. Based on these observed rotational characteristics, results will be presented on both the long- and short-term spin-rate variations of selected targets. The objective was to study a variety of satellites for rotational stability over time, and to discern how physical effects (such as YORP) might be dependent on the optical, thermal and geometrical parameters of the object. References: [1] Papushev, P., Karavaev, Y., and Mishina, M., Investigations of the evolution of optical characteristics and dynamics of proper rotation of uncontrolled geostationary artificial satellites, Advances in Space Research, 416-1422, 2009. [2] Albuja, A.A. and Scheeres, D.J., Defunct Satellites, Rotation Rates and the YORP Effect, Proceedings of the Advanced Maui Optical and Space Surveillance Technologies Conference, Wailea, Hawaii, 156-163, 2013. [3] Romero, V., W.H. Ryan, and E.V. Ryan, Monitoring Variations to the Near-Earth Space Environment during High Solar Activity using Orbiting Rocket Bodies, Proceedings of the 2007 AMOS Technical Conference, Hawaii, 389-393, 2007.
Image Location Estimation by Salient Region Matching.
Qian, Xueming; Zhao, Yisi; Han, Junwei
2015-11-01
Nowadays, locations of images have been widely used in many application scenarios for large geo-tagged image corpora. As to images which are not geographically tagged, we estimate their locations with the help of the large geo-tagged image set by content-based image retrieval. In this paper, we exploit spatial information of useful visual words to improve image location estimation (or content-based image retrieval performances). We proposed to generate visual word groups by mean-shift clustering. To improve the retrieval performance, spatial constraint is utilized to code the relative position of visual words. We proposed to generate a position descriptor for each visual word and build fast indexing structure for visual word groups. Experiments show the effectiveness of our proposed approach.
Assessment of Aerosol Distributions from GEOS-5 Using the CALIPSO Feature Mask
NASA Technical Reports Server (NTRS)
Welton, Ellsworth
2010-01-01
A-train sensors such as MODIS, MISR, and CALIPSO are used to determine aerosol properties, and in the process a means of estimating aerosol type (e.g. smoke vs. dust). Correct classification of aerosol type is important for climate assessment, air quality applications, and for comparisons and analysis with aerosol transport models. The Aerosols-Clouds-Ecosystems (ACE) satellite mission proposed in the NRC Decadal Survey describes a next generation aerosol and cloud suite similar to the current A-train, including a lidar. The future ACE lidar must be able to determine aerosol type effectively in conjunction with modeling activities to achieve ACE objectives. Here we examine the current capabilities of CALIPSO and the NASA Goddard Earth Observing System general circulation model and data assimilation system (GEOS-5), to place future ACE needs in context. The CALIPSO level 2 feature mask includes vertical profiles of aerosol layers classified by type. GEOS-5 provides global 3D aerosol mass for sulfate, sea salt, dust, and black and organic carbon. A GEOS aerosol scene classification algorithm has been developed to provide estimates of aerosol mixtures and extinction profiles along the CALIPSO orbit track. In previous work, initial comparisons between GEOS-5 derived aerosol mixtures and CALIPSO derived aerosol types were presented for July 2007. In general, the results showed that model and lidar derived aerosol types did not agree well in the boundary layer. Agreement was poor over Europe, where CALIPSO indicated the presence of dust and pollution mixtures yet GEOS-5 was dominated by pollution with little dust. Over the ocean in the tropics, the model appeared to contain less sea salt than detected by CALIPSO, yet at high latitudes the situation was reserved. Agreement between CALIPSO and GEOS-5, aerosol types improved above the boundary layer, primarily in dust and smoke dominated regions. At higher altitudes (> 5 km), the model contained aerosol layers not detected by CALIPSO. Here we present new results for a full year study using the new Version 3 CALIPSO data and most recent GEOS-5 model results.
NASA Astrophysics Data System (ADS)
Ross, L. E.; Kelly, M.; Springer, A. E.
2003-12-01
In the Fall semester of 2003, Northern Arizona University will introduce the GeoWall to its introductory geology courses. This presents an opportunity to assess the impact of this new technology on students' understanding of basic topographic concepts and the spatial relationships between geology, topography, and hydrology on a field trip. Introductory Geology fulfills the Lab Science component of the Liberal Studies Program at Northern Arizona University. The class is open to all Northern Arizona University students, and is most commonly taken by non-science majors. In this class students learn to: locate their position using maps, identify common minerals and rocks, recognize the relationship between geology and geomorphology, visualize how rocks exposed at the surface continue into the subsurface, and to draw conclusions about possible geologic hazards in different settings. In this study we will report how a GeoWall 3D visualization technology was used in a field study of a graben south of Flagstaff. The goal of the field exercise is to improve students' ability to synthesize data collected at field stops into a conceptual model of the graben, linking geology, geomorphology and hydrology. We plan to present a quantitative assessment of the GeoWall learning objectives from data collected from a paired test and control group of students. Teaching assistants (TAs) with two or more lab classes have been identified; these TAs will participate in both GeoWall and non-GeoWall lab exercises. The GeoWall use will occur outside of normal lab hours to avoid disrupting the lab schedule during the eighth week of lab. This field preparation exercise includes a 3D visualization of the Lake Mary graben rendered with the ROMA software. The following week, all students attend the graben field trip; immediately following the trip, students will interviewed about their gain in understanding of the geologic features illustrated during the field trip. The results of the post-fieldtrip interviews will also be presented to quantitatively assess how students perceive the use of the GeoWall in this introductory geology setting, and how it affected their understanding.
geoKepler Workflow Module for Computationally Scalable and Reproducible Geoprocessing and Modeling
NASA Astrophysics Data System (ADS)
Cowart, C.; Block, J.; Crawl, D.; Graham, J.; Gupta, A.; Nguyen, M.; de Callafon, R.; Smarr, L.; Altintas, I.
2015-12-01
The NSF-funded WIFIRE project has developed an open-source, online geospatial workflow platform for unifying geoprocessing tools and models for for fire and other geospatially dependent modeling applications. It is a product of WIFIRE's objective to build an end-to-end cyberinfrastructure for real-time and data-driven simulation, prediction and visualization of wildfire behavior. geoKepler includes a set of reusable GIS components, or actors, for the Kepler Scientific Workflow System (https://kepler-project.org). Actors exist for reading and writing GIS data in formats such as Shapefile, GeoJSON, KML, and using OGC web services such as WFS. The actors also allow for calling geoprocessing tools in other packages such as GDAL and GRASS. Kepler integrates functions from multiple platforms and file formats into one framework, thus enabling optimal GIS interoperability, model coupling, and scalability. Products of the GIS actors can be fed directly to models such as FARSITE and WRF. Kepler's ability to schedule and scale processes using Hadoop and Spark also makes geoprocessing ultimately extensible and computationally scalable. The reusable workflows in geoKepler can be made to run automatically when alerted by real-time environmental conditions. Here, we show breakthroughs in the speed of creating complex data for hazard assessments with this platform. We also demonstrate geoKepler workflows that use Data Assimilation to ingest real-time weather data into wildfire simulations, and for data mining techniques to gain insight into environmental conditions affecting fire behavior. Existing machine learning tools and libraries such as R and MLlib are being leveraged for this purpose in Kepler, as well as Kepler's Distributed Data Parallel (DDP) capability to provide a framework for scalable processing. geoKepler workflows can be executed via an iPython notebook as a part of a Jupyter hub at UC San Diego for sharing and reporting of the scientific analysis and results from various runs of geoKepler workflows. The communication between iPython and Kepler workflow executions is established through an iPython magic function for Kepler that we have implemented. In summary, geoKepler is an ecosystem that makes geospatial processing and analysis of any kind programmable, reusable, scalable and sharable.
NASA Astrophysics Data System (ADS)
di, L.; Deng, M.
2010-12-01
Remote sensing (RS) is an essential method to collect data for Earth science research. Huge amount of remote sensing data, most of them in the image form, have been acquired. Almost all geography departments in the world offer courses in digital processing of remote sensing images. Such courses place emphasis on how to digitally process large amount of multi-source images for solving real world problems. However, due to the diversity and complexity of RS images and the shortcomings of current data and processing infrastructure, obstacles for effectively teaching such courses still remain. The major obstacles include 1) difficulties in finding, accessing, integrating and using massive RS images by students and educators, and 2) inadequate processing functions and computing facilities for students to freely explore the massive data. Recent development in geospatial Web processing service systems, which make massive data, computing powers, and processing capabilities to average Internet users anywhere in the world, promises the removal of the obstacles. The GeoBrain system developed by CSISS is an example of such systems. All functions available in GRASS Open Source GIS have been implemented as Web services in GeoBrain. Petabytes of remote sensing images in NASA data centers, the USGS Landsat data archive, and NOAA CLASS are accessible transparently and processable through GeoBrain. The GeoBrain system is operated on a high performance cluster server with large disk storage and fast Internet connection. All GeoBrain capabilities can be accessed by any Internet-connected Web browser. Dozens of universities have used GeoBrain as an ideal platform to support data-intensive remote sensing education. This presentation gives a specific example of using GeoBrain geoprocessing services to enhance the teaching of GGS 588, Digital Remote Sensing taught at the Department of Geography and Geoinformation Science, George Mason University. The course uses the textbook "Introductory Digital Image Processing, A Remote Sensing Perspective" authored by John Jensen. The textbook is widely adopted in the geography departments around the world for training students on digital processing of remote sensing images. In the traditional teaching setting for the course, the instructor prepares a set of sample remote sensing images to be used for the course. Commercial desktop remote sensing software, such as ERDAS, is used for students to do the lab exercises. The students have to do the excurses in the lab and can only use the simple images. For this specific course at GMU, we developed GeoBrain-based lab excurses for the course. With GeoBrain, students now can explore petabytes of remote sensing images in the NASA, NOAA, and USGS data archives instead of dealing only with sample images. Students have a much more powerful computing facility available for their lab excurses. They can explore the data and do the excurses any time at any place they want as long as they can access the Internet through the Web Browser. The feedbacks from students are all very positive about the learning experience on the digital image processing with the help of GeoBrain web processing services. The teaching/lab materials and GeoBrain services are freely available to anyone at http://www.laits.gmu.edu.
NASA Astrophysics Data System (ADS)
Wan Salleh, Masturah; Sulaiman, Hajar
2013-04-01
The use of technology in the teaching of mathematics at the university level has long been introduced; but many among the lecturers, especially those that have taught for many years, still opt for a traditional teaching method, that is, by lecture talk. One reason is that lecturers themselves were not exposed to the technologies available and how it can assist in the teaching and learning procedures (T&L) in mathematics. GeoGebra is a mathematical software which is open and free and has just recently been introduced in Malaysia. Compared with the software Cabri Geometry and Geometer's Sketchpad (GSP), which only focus on geometry, GeoGebra is able to connect geometry, algebra and numerical representation. Realizing this, the researchers have conducted a study to expose the university lecturers on the use of GeoGebra in T&L. The researchers chose to do the research on mathematics lecturers at the Department of Computer Science and Mathematics (JSKM), Universiti Teknologi Mara (UiTM), Penang. The objective of this study is to determine whether an exposure to GeoGebra software can affect the conceptual knowledge and procedural teaching of mathematics at the university level. This study is a combination of descriptive and qualitative. One session was conducted in an open workshop for all the 45 lecturers. From that total, four people were selected as a sample. The sample was selected by using a simple random sampling method. This study used materials in the form of modules during the workshop. In terms of conceptual knowledge, the results showed that the GeoGebra software is appropriate, relevant and highly effective for in-depth understanding of the selected topics. While the procedural aspects of teaching, it can be one of the teaching aids and considerably facilitate the lecturers.
Feature-Based Approach for the Registration of Pushbroom Imagery with Existing Orthophotos
NASA Astrophysics Data System (ADS)
Xiong, Weifeng
Low-cost Unmanned Airborne Vehicles (UAVs) are rapidly becoming suitable platforms for acquiring remote sensing data for a wide range of applications. For example, a UAV-based mobile mapping system (MMS) is emerging as a novel phenotyping tool that delivers several advantages to alleviate the drawbacks of conventional manual plant trait measurements. Moreover, UAVs equipped with direct geo-referenced frame cameras and pushbroom scanners can acquire geospatial data for comprehensive high-throughput phenotyping. UAVs for mobile mapping platforms are low-cost and easy to use, can fly closer to the objects, and are filling an important gap between ground wheel-based and traditional manned-airborne platforms. However, consumer-grade UAVs are capable of carrying only equipment with a relatively light payload and their flying time is determined by a limited battery life. These restrictions of UAVs unfortunately force potential users to adopt lower-quality direct geo-referencing and imaging systems that may negatively impact the quality of the deliverables. Recent advances in sensor calibration and automated triangulation have made it feasible to obtain accurate mapping using low-cost camera systems equipped with consumer-grade GNSS/INS units. However, ortho-rectification of the data from a linear-array scanner is challenging for low-cost UAV systems, because the derived geo-location information from pushbroom sensors is quite sensitive to the performance of the implemented direct geo-referencing unit. This thesis presents a novel approach for improving the ortho-rectification of hyperspectral pushbroom scanner imagery with the aid of orthophotos generated from frame cameras through the identification of conjugate features while modeling the impact of residual artifacts in the direct geo-referencing information. The experimental results qualitatively and quantitatively proved the feasibility of the proposed methodology in improving the geo-referencing accuracy of real datasets collected over an agricultural field.
Spectroscopic Characterization of GEO Satellites with Gunma LOW Resolution Spectrograph
NASA Astrophysics Data System (ADS)
Endo, T.; Ono, H.; Hosokawa, M.; Ando, T.; Takanezawa, T.; Hashimoto, O.
The spectroscopic observation is potentially a powerful tool for understanding the Geostationary Earth Orbit (GEO) objects. We present here the results of an investigation of energy spectra of GEO satellites obtained from a groundbased optical telescope. The spectroscopic observations were made from April to June 2016 with the Gunma LOW resolution Spectrograph and imager (GLOWS) at the Gunma Astronomical Observatory (GAO) in JAPAN. The observation targets consist of eleven different satellites: two weather satellites, four communications satellites, and five broadcasting satellites. All the spectra of those GEO satellites are inferred to be solar-like. A number of well-known absorption features such as H-alpha, H-beta, Na-D,water vapor and oxygen molecules are clearly seen in thewavelength range of 4,000 - 8,000 Å. For comparison, we calculated the intensity ratio of the spectra of GEO satellites to that of the Moon which is the natural satellite of the earth. As a result, the following characteristics were obtained. 1) Some variations are seen in the strength of absorption features of water vapor and oxygen originated by the telluric atmosphere, but any other characteristic absorption features were not found. 2) For all observed satellites, the intensity ratio of the spectrum of GEO satellites decrease as a function of wavelength or to be flat. It means that the spectral reflectance of satellite materials is bluer than that of the Moon. 3) A characteristic dip at around 4,800 Å is found in all observed spectra of a weather satellite. Based on these observations, it is indicated that the characteristics of the spectrum are mainly derived from the solar panels because the apparent area of the solar cell is probably larger than that of the satellite body.
NASA Astrophysics Data System (ADS)
Hughes, J.; Schaub, H.
2017-12-01
Spacecraft can charge to very negative voltages at GEO due to interactions with the space plasma. This can cause arcing which can damage spacecraft electronics or solar panels. Recently, it has been suggested that spacecraft charging may lead to orbital perturbations which change the orbits of lightweight uncontrolled debris orbits significantly. The motions of High Area to Mass Ratio objects are not well explained with just perturbations from Solar Radiation Pressure (SRP) and earth, moon, and sun gravity. A charged spacecraft will experience a Lorentz force as the spacecraft moves relative to Earth's magnetic field, as well as a Lorentz torque and eddy current torques if the object is rotating. Prior work assuming a constant "worst case" voltage has shown that Lorentz and eddy torques can cause quite large orbital changes by rotating the object to experience more or less SRP. For some objects, including or neglecting these electromagnetic torques can lead to differences of thousands of kilometers after only two orbits. This paper will further investigate the effects of electromagnetic perturbations by using a charging model that uses measured flux distributions to better simulate natural charging. This differs from prior work which used a constant voltage or Maxwellian distributions. This is done to a calm space weather case of Kp = 2 and a stormy case where Kp = 8. Preliminary analysis suggests that electrostatics will still cause large orbital changes even with the more realistic charging model.
Towards Precise Metadata-set for Discovering 3D Geospatial Models in Geo-portals
NASA Astrophysics Data System (ADS)
Zamyadi, A.; Pouliot, J.; Bédard, Y.
2013-09-01
Accessing 3D geospatial models, eventually at no cost and for unrestricted use, is certainly an important issue as they become popular among participatory communities, consultants, and officials. Various geo-portals, mainly established for 2D resources, have tried to provide access to existing 3D resources such as digital elevation model, LIDAR or classic topographic data. Describing the content of data, metadata is a key component of data discovery in geo-portals. An inventory of seven online geo-portals and commercial catalogues shows that the metadata referring to 3D information is very different from one geo-portal to another as well as for similar 3D resources in the same geo-portal. The inventory considered 971 data resources affiliated with elevation. 51% of them were from three geo-portals running at Canadian federal and municipal levels whose metadata resources did not consider 3D model by any definition. Regarding the remaining 49% which refer to 3D models, different definition of terms and metadata were found, resulting in confusion and misinterpretation. The overall assessment of these geo-portals clearly shows that the provided metadata do not integrate specific and common information about 3D geospatial models. Accordingly, the main objective of this research is to improve 3D geospatial model discovery in geo-portals by adding a specific metadata-set. Based on the knowledge and current practices on 3D modeling, and 3D data acquisition and management, a set of metadata is proposed to increase its suitability for 3D geospatial models. This metadata-set enables the definition of genuine classes, fields, and code-lists for a 3D metadata profile. The main structure of the proposal contains 21 metadata classes. These classes are classified in three packages as General and Complementary on contextual and structural information, and Availability on the transition from storage to delivery format. The proposed metadata set is compared with Canadian Geospatial Data Infrastructure (CGDI) metadata which is an implementation of North American Profile of ISO-19115. The comparison analyzes the two metadata against three simulated scenarios about discovering needed 3D geo-spatial datasets. Considering specific metadata about 3D geospatial models, the proposed metadata-set has six additional classes on geometric dimension, level of detail, geometric modeling, topology, and appearance information. In addition classes on data acquisition, preparation, and modeling, and physical availability have been specialized for 3D geospatial models.
Quality control of 3D Geological Models using an Attention Model based on Gaze
NASA Astrophysics Data System (ADS)
Busschers, Freek S.; van Maanen, Peter-Paul; Brouwer, Anne-Marie
2014-05-01
The Geological Survey of the Netherlands (GSN) produces 3D stochastic geological models of the upper 50 meters of the Dutch subsurface. The voxel models are regarded essential in answering subsurface questions on, for example, aggregate resources, groundwater flow, land subsidence studies and the planning of large-scale infrastructural works such as tunnels. GeoTOP is the most recent and detailed generation of 3D voxel models. This model describes 3D lithological variability up to a depth of 50 m using voxels of 100*100*0.5m. Due to the expected increase in data-flow, model output and user demands, the development of (semi-)automated quality control systems is getting more important in the near future. Besides numerical control systems, capturing model errors as seen from the expert geologist viewpoint is of increasing interest. We envision the use of eye gaze to support and speed up detection of errors in the geological voxel models. As a first step in this direction we explore gaze behavior of 12 geological experts from the GSN during quality control of part of the GeoTOP 3D geological model using an eye-tracker. Gaze is used as input of an attention model that results in 'attended areas' for each individual examined image of the GeoTOP model and each individual expert. We compared these attended areas to errors as marked by the experts using a mouse. Results show that: 1) attended areas as determined from experts' gaze data largely match with GeoTOP errors as indicated by the experts using a mouse, and 2) a substantial part of the match can be reached using only gaze data from the first few seconds of the time geologists spend to search for errors. These results open up the possibility of faster GeoTOP model control using gaze if geologists accept a small decrease of error detection accuracy. Attention data may also be used to make independent comparisons between different geologists varying in focus and expertise. This would facilitate a more effective use of experts in specific different projects or areas. Part of such a procedure could be to confront geological experts with their own results, allowing possible training steps in order to improve their geological expertise and eventually improve the GeoTop model. Besides the directions as indicated above, future research should focus on concrete implementation of facilitating and optimizing error detection in present and future 3D voxel models that are commonly characterized by very large amounts of data.
Combined Recipe for Clinical Target Volume and Planning Target Volume Margins
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stroom, Joep, E-mail: joep.stroom@fundacaochampalimaud.pt; Gilhuijs, Kenneth; Vieira, Sandra
2014-03-01
Purpose: To develop a combined recipe for clinical target volume (CTV) and planning target volume (PTV) margins. Methods and Materials: A widely accepted PTV margin recipe is M{sub geo} = aΣ{sub geo} + bσ{sub geo}, with Σ{sub geo} and σ{sub geo} standard deviations (SDs) representing systematic and random geometric uncertainties, respectively. On the basis of histopathology data of breast and lung tumors, we suggest describing the distribution of microscopic islets around the gross tumor volume (GTV) by a half-Gaussian with SD Σ{sub micro}, yielding as possible CTV margin recipe: M{sub micro} = ƒ(N{sub i}) × Σ{sub micro}, with N{sub i}more » the average number of microscopic islets per patient. To determine ƒ(N{sub i}), a computer model was developed that simulated radiation therapy of a spherical GTV with isotropic distribution of microscopic disease in a large group of virtual patients. The minimal margin that yielded D{sub min} <95% in maximally 10% of patients was calculated for various Σ{sub micro} and N{sub i}. Because Σ{sub micro} is independent of Σ{sub geo}, we propose they should be added quadratically, yielding for a combined GTV-to-PTV margin recipe: M{sub GTV-PTV} = √([aΣ{sub geo}]{sup 2} + [ƒ(N{sub i})Σ{sub micro}]{sup 2}) + bσ{sub geo}. This was validated by the computer model through numerous simultaneous simulations of microscopic and geometric uncertainties. Results: The margin factor ƒ(N{sub i}) in a relevant range of Σ{sub micro} and N{sub i} can be given by: ƒ(N{sub i}) = 1.4 + 0.8log(N{sub i}). Filling in the other factors found in our simulations (a = 2.1 and b = 0.8) yields for the combined recipe: M{sub GTV-PTV} = √((2.1Σ{sub geo}){sup 2} + ([1.4 + 0.8log(N{sub i})] × Σ{sub micro}){sup 2}) + 0.8σ{sub geo}. The average margin difference between the simultaneous simulations and the above recipe was 0.2 ± 0.8 mm (1 SD). Calculating M{sub geo} and M{sub micro} separately and adding them linearly overestimated PTVs by on average 5 mm. Margin recipes based on tumor control probability (TCP) instead of D{sub min} criteria yielded similar results. Conclusions: A general recipe for GTV-to-PTV margins is proposed, which shows that CTV and PTV margins should be added in quadrature instead of linearly.« less
NASA Astrophysics Data System (ADS)
Mozgovoy, Dmitry k.; Hnatushenko, Volodymyr V.; Vasyliev, Volodymyr V.
2018-04-01
Vegetation and water bodies are a fundamental element of urban ecosystems, and water mapping is critical for urban and landscape planning and management. A methodology of automated recognition of vegetation and water bodies on the territory of megacities in satellite images of sub-meter spatial resolution of the visible and IR bands is proposed. By processing multispectral images from the satellite SuperView-1A, vector layers of recognized plant and water objects were obtained. Analysis of the results of image processing showed a sufficiently high accuracy of the delineation of the boundaries of recognized objects and a good separation of classes. The developed methodology provides a significant increase of the efficiency and reliability of updating maps of large cities while reducing financial costs. Due to the high degree of automation, the proposed methodology can be implemented in the form of a geo-information web service functioning in the interests of a wide range of public services and commercial institutions.
Relative Velocity as a Metric for Probability of Collision Calculations
NASA Technical Reports Server (NTRS)
Frigm, Ryan Clayton; Rohrbaugh, Dave
2008-01-01
Collision risk assessment metrics, such as the probability of collision calculation, are based largely on assumptions about the interaction of two objects during their close approach. Specifically, the approach to probabilistic risk assessment can be performed more easily if the relative trajectories of the two close approach objects are assumed to be linear during the encounter. It is shown in this analysis that one factor in determining linearity is the relative velocity of the two encountering bodies, in that the assumption of linearity breaks down at low relative approach velocities. The first part of this analysis is the determination of the relative velocity threshold below which the assumption of linearity becomes invalid. The second part is a statistical study of conjunction interactions between representative asset spacecraft and the associated debris field environment to determine the likelihood of encountering a low relative velocity close approach. This analysis is performed for both the LEO and GEO orbit regimes. Both parts comment on the resulting effects to collision risk assessment operations.
NASA Technical Reports Server (NTRS)
Fishman, J.; Iraci, Laura T.; Al-Saddi, J.; Chance, K.; Chavez, F.; Chin, M.; Coble, P.; Davis, C.; DiGiacomo, P. M.; Edwards, D.;
2012-01-01
The Geostationary Coastal and Air Pollution Events (GEO-CAPE) mission was recommended by the National Research Council's (NRC's) Earth Science Decadal Survey to measure tropospheric trace gases and aerosols and coastal ocean phytoplankton, water quality, and biogeochemistry from geostationary orbit, providing continuous observations within the field of view. To fulfill the mandate and address the challenge put forth by the NRC, two GEO-CAPE Science Working Groups (SWGs), representing the atmospheric composition and ocean color disciplines, have developed realistic science objectives using input drawn from several community workshops. The GEO-CAPE mission will take advantage of this revolutionary advance in temporal frequency for both of these disciplines. Multiple observations per day are required to explore the physical, chemical, and dynamical processes that determine tropospheric composition and air quality over spatial scales ranging from urban to continental, and over temporal scales ranging from diurnal to seasonal. Likewise, high-frequency satellite observations are critical to studying and quantifying biological, chemical, and physical processes within the coastal ocean. These observations are to be achieved from a vantage point near 95deg-100degW, providing a complete view of North America as well as the adjacent oceans. The SWGs have also endorsed the concept of phased implementation using commercial satellites to reduce mission risk and cost. GEO-CAPE will join the global constellation of geostationary atmospheric chemistry and coastal ocean color sensors planned to be in orbit in the 2020 time frame.
ESONET , a milestone towards sustained multidisciplinary ocean observation.
NASA Astrophysics Data System (ADS)
Rolin, J.-F.
2012-04-01
At the end of a 4 year project dedicated to the constitution of a Network of Excellence (NoE) on subsea observatories in Europe, large expectations are still in the agenda. The economical crisis changes the infrastructure construction planning in many ways but the objectives are quite clear and may be reached at European scale. The overall objective of the ESONET NoE was to create an organisation able to implement, operate and maintain a sustainable underwater observation network, extending into deep water, capable of monitoring biological, geo-chemical, geological, geophysical and physical processes occurring throughout the water column, sea floor interface and solid earth below. This main objective of ESONET has been met by creating the network of 11 permanent underwater observation sites together with the "ESONET Vi" Virtual Institute organising the exchange of staff and joint experiments on EMSO large research infrastructure observatories. The development of recommendations on best practices, standardization and interoperability concepts concerning underwater observatory equipment, as synthetized by the so called ESONET Label document has been created. The ESONET Label is a set of criteria to be met by the deep-sea observatory equipment as well as recommended solutions and options to guarantee their optimal operation in the ocean over long time periods. ESONET contributes to the fixed point sustained observatory community which extends worldwide, is fully multidisciplinary and in its way may open a new page in ocean sciences history.
Corrêa, Claudia V S; Reis, Fábio A G V; Giordano, Lucilia C; Bressane, Adriano; Chaves, Camila J; Amaral, Ana Maria C DO; Brito, Hermes D; Medeiros, Gerson A DE
2017-01-01
The geo-environmental zoning represents an important strategy in the territorial management. However, it requires a logical and structured procedure. Therefore, an approach using physiographic compartmentalization is proposed and applied as case study in a region covered by the topographic maps of São José dos Campos and Jacareí, Brazil. This region has great geological and geomorphological peculiarities, beyond being a place with large human interventions because of its quickly economic growth. The methodology is based on photointerpretation techniques and remote sensing in GIS environment. As a result, seven geo-environmental zones were obtained from a weighted integration by multicriteria analysis of physiographic units with land-use classes. In conclusion, taking into account potentialities and limitations, the proposed approach can be considered able to support sustainable decision-making, being applicable in other regions.
Static pile load tests on driven piles in Intermediate-Geo Materials : research brief.
DOT National Transportation Integrated Search
2017-02-01
Research Objectives: : Investigate the use of modified standard penetration tests (MSPT) : Compare field results with predictions made by the WisDOT driving formula, PDA and CAPWAP : Improve prediction of pile lengths and pile capacities ...
DOT National Transportation Integrated Search
2010-04-01
Objectives : Evaluate the ability of biofuel co-product (BCP) to function as an effective soil stabilizing agent. : Investigate the effect of BCP on the engineering properties of soil-BCP mixtures for Iowa conditions.
Advanced propulsion for LEO and GEO platforms
NASA Technical Reports Server (NTRS)
Sovey, James S.; Pidgeon, David J.
1990-01-01
Mission requirements and mass savings applicable to specific low earth orbit and geostationary earth orbit platforms using three highly developed propulsion systems are described. Advanced hypergolic bipropellant thrusters and hydrazine arcjets can provide about 11 percent additional instrument payload to 14,000 kg LEO platforms. By using electric propulsion on a 8,000 kg class GEO platform, mass savings in excess of 15 percent of the beginning-of-life platform mass are obtained. Effects of large, advanced technology solar arrays and antennas on platform propulsion requirements are also discussed.
LEO-to-GEO low thrust chemical propulsion
NASA Technical Reports Server (NTRS)
Shoji, J. M.
1980-01-01
One approach being considered for transporting large space structures from low Earth orbit (LEO) to geosynchronous equatorial orbit (GEO) is the use of low thrust chemical propulsion systems. A variety of chemical rocket engine cycles evaluated for this application for oxygen/hydrogen and oxygen/hydrocarbon propellants (oxygen/methane and oxygen/RF-1) are discussed. These cycles include conventional propellant turbine drives, turboalternator/electric motor pump drive, and fuel cell/electric motor pump drive as well as pressure fed engines. Thrust chamber cooling analysis results are presented for regenerative/radiation and film/radiation cooling.
Transfer Orbit Plasma Interaction Experiment (TROPIX)
NASA Astrophysics Data System (ADS)
Hickman, Mark
Viewgraphs on the Transfer Orbit Plasma Interaction Experiment (TROPIX) are presented. Objectives of this research are (1) to map the charged particles in Earth's magnetosphere from LEO to GEO at high inclinations; (2) to measure plasma current collection and resulting shifts in vehicle electrical potential from LEO to GEO across range of orbital inclinations; (3) to study spacecraft interaction with plasma environment using solar electric propulsion (SEP) thrusters as plasma contactors; (4) to measure array degradation over mission duration; (5) to evaluate the potential of various microelectronics, spacecraft components, and instruments for future space missions; and (6) to demonstrate SEP technology applied to a flight vehicle. An overview of TROPIX is presented.
Implementing Marine Organic Aerosols Into the GEOS-Chem Model
NASA Technical Reports Server (NTRS)
Johnson, Matthew S.
2015-01-01
Marine-sourced organic aerosols (MOA) have been shown to play an important role in tropospheric chemistry by impacting surface mass, cloud condensation nuclei, and ice nuclei concentrations over remote marine and coastal regions. In this work, an online marine primary organic aerosol emission parameterization, designed to be used for both global and regional models, was implemented into the GEOS-Chem model. The implemented emission scheme improved the large under-prediction of organic aerosol concentrations in clean marine regions (normalized mean bias decreases from -79% when using the default settings to -12% when marine organic aerosols are added). Model predictions were also in good agreement (correlation coefficient of 0.62 and normalized mean bias of -36%) with hourly surface concentrations of MOA observed during the summertime at an inland site near Paris, France. Our study shows that MOA have weaker coastal-to-inland concentration gradients than sea-salt aerosols, leading to several inland European cities having > 10% of their surface submicron organic aerosol mass concentration with a marine source. The addition of MOA tracers to GEOS-Chem enabled us to identify the regions with large contributions of freshly-emitted or aged aerosol having distinct physicochemical properties, potentially indicating optimal locations for future field studies.
Ground moving target geo-location from monocular camera mounted on a micro air vehicle
NASA Astrophysics Data System (ADS)
Guo, Li; Ang, Haisong; Zheng, Xiangming
2011-08-01
The usual approaches to unmanned air vehicle(UAV)-to-ground target geo-location impose some severe constraints to the system, such as stationary objects, accurate geo-reference terrain database, or ground plane assumption. Micro air vehicle(MAV) works with characteristics including low altitude flight, limited payload and onboard sensors' low accuracy. According to these characteristics, a method is developed to determine the location of ground moving target which imaged from the air using monocular camera equipped on MAV. This method eliminates the requirements for terrain database (elevation maps) and altimeters that can provide MAV's and target's altitude. Instead, the proposed method only requires MAV flight status provided by its inherent onboard navigation system which includes inertial measurement unit(IMU) and global position system(GPS). The key is to get accurate information on the altitude of the ground moving target. First, Optical flow method extracts background static feature points. Setting a local region around the target in the current image, The features which are on the same plane with the target in this region are extracted, and are retained as aided features. Then, inverse-velocity method calculates the location of these points by integrated with aircraft status. The altitude of object, which is calculated by using position information of these aided features, combining with aircraft status and image coordinates, geo-locate the target. Meanwhile, a framework with Bayesian estimator is employed to eliminate noise caused by camera, IMU and GPS. Firstly, an extended Kalman filter(EKF) provides a simultaneous localization and mapping solution for the estimation of aircraft states and aided features location which defines the moving target local environment. Secondly, an unscented transformation(UT) method determines the estimated mean and covariance of target location from aircraft states and aided features location, and then exports them for the moving target Kalman filter(KF). Experimental results show that our method can instantaneously geo-locate the moving target by operator's single click and can reach 15 meters accuracy for an MAV flying at 200 meters above the ground.
Solar Radiation Pressure Binning for the Geosynchronous Orbit
NASA Technical Reports Server (NTRS)
Hejduk, M. D.; Ghrist, R. W.
2011-01-01
Orbital maintenance parameters for individual satellites or groups of satellites have traditionally been set by examining orbital parameters alone, such as through apogee and perigee height binning; this approach ignored the other factors that governed an individual satellite's susceptibility to non-conservative forces. In the atmospheric drag regime, this problem has been addressed by the introduction of the "energy dissipation rate," a quantity that represents the amount of energy being removed from the orbit; such an approach is able to consider both atmospheric density and satellite frontal area characteristics and thus serve as a mechanism for binning satellites of similar behavior. The geo-synchronous orbit (of broader definition than the geostationary orbit -- here taken to be from 1300 to 1800 minutes in orbital period) is not affected by drag; rather, its principal non-conservative force is that of solar radiation pressure -- the momentum imparted to the satellite by solar radiometric energy. While this perturbation is solved for as part of the orbit determination update, no binning or division scheme, analogous to the drag regime, has been developed for the geo-synchronous orbit. The present analysis has begun such an effort by examining the behavior of geosynchronous rocket bodies and non-stabilized payloads as a function of solar radiation pressure susceptibility. A preliminary examination of binning techniques used in the drag regime gives initial guidance regarding the criteria for useful bin divisions. Applying these criteria to the object type, solar radiation pressure, and resultant state vector accuracy for the analyzed dataset, a single division of "large" satellites into two bins for the purposes of setting related sensor tasking and orbit determination (OD) controls is suggested. When an accompanying analysis of high area-to-mass objects is complete, a full set of binning recommendations for the geosynchronous orbit will be available.
NASA Astrophysics Data System (ADS)
Fathy, Ibrahim
2016-07-01
This paper presents a statistical study of different types of large-scale geomagnetic pulsation (Pc3, Pc4, Pc5 and Pi2) detected simultaneously by two MAGDAS stations located at Fayum (Geo. Coordinates 29.18 N and 30.50 E) and Aswan (Geo. Coordinates 23.59 N and 32.51 E) in Egypt. The second order butter-worth band-pass filter has been used to filter and analyze the horizontal H-component of the geomagnetic field in one-second data. The data was collected during the solar minimum of the current solar cycle 24. We list the most energetic pulsations detected by the two stations instantaneously, in addition; the average amplitude of the pulsation signals was calculated.
Zhu, Yun Guang; Wang, Ye; Han, Zhao Jun; Shi, Yumeng; Wong, Jen It; Huang, Zhi Xiang; Ostrikov, Kostya Ken; Yang, Hui Ying
2014-12-21
The catalytic role of germanium (Ge) was investigated to improve the electrochemical performance of tin dioxide grown on graphene (SnO(2)/G) nanocomposites as an anode material of lithium ion batteries (LIBs). Germanium dioxide (GeO(20) and SnO(2) nanoparticles (<10 nm) were uniformly anchored on the graphene sheets via a simple single-step hydrothermal method. The synthesized SnO(2)(GeO(2))0.13/G nanocomposites can deliver a capacity of 1200 mA h g(-1) at a current density of 100 mA g(-1), which is much higher than the traditional theoretical specific capacity of such nanocomposites (∼ 702 mA h g(-1)). More importantly, the SnO(2)(GeO(2))0.13/G nanocomposites exhibited an improved rate, large current capability (885 mA h g(-1) at a discharge current of 2000 mA g(-1)) and excellent long cycling stability (almost 100% retention after 600 cycles). The enhanced electrochemical performance was attributed to the catalytic effect of Ge, which enabled the reversible reaction of metals (Sn and Ge) to metals oxide (SnO(2) and GeO(2)) during the charge/discharge processes. Our demonstrated approach towards nanocomposite catalyst engineering opens new avenues for next-generation high-performance rechargeable Li-ion batteries anode materials.
How best to geo-reference farms? A case study from Cornwall, England.
Durr, P A; Froggatt, A E A
2002-11-29
The commonest way of geo-referencing farms as single points is using the location of the farmhouse as either read off a map or approximated by its postcode. While these two methods may be adequate for small farms, they are unlikely to be satisfactory for large ones, or alternatively when they are comprised of several discrete units or holdings. In order to investigate the best representation of the total farm polygon(s) by a single point, we undertook a study using nearly 500 actual farm boundaries in the county of Cornwall, England. For each farm, the farm boundaries were digitised, and its area and centroid determined using ArcView 3.2. A variety of point geo-referencing systems were tested to find the best single point location for a farm, as judged by the proportion of farm area captured. Whilst the centroid was found to capture the largest area, the main farm building was judged to be the best geo-referencing method for practical purposes. In contrast, the various systems of geo-coding using the farm postal address performed relatively poorly. Where there are separate parcels of land managed together in a single parish, they may be identified as a single unit, but if there are separate parcels in different parishes they should be identified as separate units.The implications of these results for Great Britain's national animal health information system (VETNET) are discussed.
NASA Technical Reports Server (NTRS)
Doelling, David R.; Scarino, Benjamin R.; Morstad, Daniel; Gopalan, Arun; Bhatt, Rajendra; Lukashin, Constantine; Minnis, Patrick
2013-01-01
Spectral band differences between sensors can complicate the process of intercalibration of a visible sensor against a reference sensor. This can be best addressed by using a hyperspectral reference sensor whenever possible because they can be used to accurately mitigate the band differences. This paper demonstrates the feasibility of using operational Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) large-footprint hyperspectral radiances to calibrate geostationary Earth-observing (GEO) sensors. Near simultaneous nadir overpass measurements were used to compare the temporal calibration of SCIAMACHY with Aqua Moderate Resolution Imaging Spectroradiometer band radiances, which were found to be consistent to within 0.44% over seven years. An operational SCIAMACHY/GEO ray-matching technique was presented, along with enhancements to improve radiance pair sampling. These enhancements did not bias the underlying intercalibration and provided enough sampling to allow up to monthly monitoring of the GEO sensor degradation. The results of the SCIAMACHY/GEO intercalibration were compared with other operational four-year Meteosat-9 0.65-µm calibration coefficients and were found to be within 1% of the gain, and more importantly, it had one of the lowest temporal standard errors of all the methods. This is more than likely that the GEO spectral response function could be directly applied to the SCIAMACHY radiances, whereas the other operational methods inferred a spectral correction factor. This method allows the validation of the spectral corrections required by other methods.
USDA-ARS?s Scientific Manuscript database
All agricultural systems have environmental and societal costs and benefits that should be objectively quantified before recommending specific management practices. Agricultural biotechnology, which takes advantage of genetically engineered organisms (GEOs), along with organic cropping systems, econ...
NASA Astrophysics Data System (ADS)
Lawhead, Pamela B.; Aten, Michelle L.
2003-04-01
The Center for GeoSpatial Workforce Development is embarking on a new era in education by developing a repository of dynamic online courseware authored by the foremost industry experts within the remote sensing and GIS industries. Virtual classrooms equipped with the most advanced instructions, computations, communications, course evaluation, and management facilities amplify these courses to enhance the learning environment and provide rapid feedback between instructors and students. The launch of this program included the objective development of the Model Curriculum by an independent consortium of remote sensing industry leaders. The Center's research and development focus on recruiting additional industry experts to develop the technical content of the courseware and then utilize state-of-the-art technology to enhance their material with visually stimulating animations, compelling audio clips and entertaining, interactive exercises intended to reach the broadest audience possible by targeting various learning styles. The courseware will be delivered via various media: Internet, CD-ROM, DVD, and compressed video, that translates into anywhere, anytime delivery of GeoSpatial Information Technology education.
NASA Technical Reports Server (NTRS)
Barker, Edwin S.; Matney, M. J.; Liou, J.-C.; Abercromby, K. J.; Rodriquez, H. M.; Seitzer, P.
2006-01-01
Since 2002 the National Aeronautics and Space Administration (NASA) has carried out an optical survey of the debris environment in the geosynchronous Earth-orbit (GEO) region with the Michigan Orbital Debris Survey Telescope (MODEST) in Chile. The survey coverage has been similar for 4 of the 5 years allowing us to follow the orbital evolution of Correlated Targets (CTs), both controlled and un-controlled objects, and Un-Correlated Targets (UCTs). Under gravitational perturbations the distributions of uncontrolled objects, both CTs and UCTs, in GEO orbits will evolve in predictable patterns, particularly evident in the inclination and right ascension of the ascending node (RAAN) distributions. There are several clusters (others have used a "cloud" nomenclature) in observed distributions that show evolution from year to year in their inclination and ascending node elements. However, when MODEST is in survey mode (field-of-view approx.1.3deg) it provides only short 5-8 minute orbital arcs which can only be fit under the assumption of a circular orbit approximation (ACO) to determine the orbital parameters. These ACO elements are useful only in a statistical sense as dedicated observing runs would be required to obtain sufficient orbital coverage to determine a set of accurate orbital elements and then to follow their evolution. Identification of the source(s) for these "clusters of UCTs" would be advantageous to the overall definition of the GEO orbital debris environment. This paper will set out to determine if the ACO elements can be used to in a statistical sense to identify the source of the "clustering of UCTs" roughly centered on an inclination of 12deg and a RAAN of 345deg. The breakup of the Titan 3C-4 transtage on February 21, 1992 has been modeled using NASA s LEGEND (LEO-to-GEO Environment Debris) code to generate a GEO debris cloud. Breakup fragments are created based on the NASA Standard Breakup Model (including fragment size, area-to-mass (A/M), and delta-V distributions). Once fragments are created, they are propagated forward in time with a subroutine GEOPROP. Perturbations included in GEOPROP are those due to solar/lunar gravity, radiation pressure, and major geopotential terms. The question to be addressed: are the UCTs detected by MODEST in this inclination/RAAN region related to the Titan 3C-4 breakup? Discussion will include the observational biases in attempting to detect a specific, uncontrolled target during given observing session. These restrictions include: (1) the length of the observing session which is 8 hours or less at any given date or declination; (2) the assumption of ACO elements for detected object when the breakup model predicts debris with non-zero eccentricities; (3) the size and illumination or brightness of the debris predicted by the model and the telescope/sky limiting magnitude.
NASA Astrophysics Data System (ADS)
Zimmer, P.; McGraw, J. T.; Ackermann, M. R.
There is considerable interest in the capability to discover and monitor small objects (d 20cm) in geosynchronous (GEO) and near-GEO orbital regimes using small, ground-based optical telescopes (D < 0.5m). The threat of such objects is clear. Small telescopes have an unrivaled cost advantage and, under ideal lighting and sky conditions, have the capability of detecting faint objects. This combination of conditions, however, is relatively rare, making routine and persistent surveillance more challenging. In a truly geostationary orbit, a small object is easy to detect because its apparent rate of motion is nearly zero for a ground-based observer, and signal accumulation occurs as it would for more traditional sidereal-tracked astronomical observations. In this regime, though, small objects are not expected to be in controlled or predictable orbits, thus a range of inclinations and eccentricities is possible. This results in a range of apparent angular rates and directions that must be surveilled. This firmly establishes this task as uncued or blind surveillance. Detections in this case are subject to what is commonly called “trailing loss,” where the signal from the object does not accumulate in a fixed detection element, resulting in far lower sensitivity than for a similar object optimally tracked. We review some of the limits of detecting these objects under less than ideal observing conditions, subject further to the current limitations based on technological and operational realities. We demonstrate progress towards this goal using telescopes much smaller than normally considered viable for this task using novel detection and analysis techniques.
Use and Evaluation of 3D GeoWall Visualizations in Undergraduate Space Science Classes
NASA Astrophysics Data System (ADS)
Turner, N. E.; Hamed, K. M.; Lopez, R. E.; Mitchell, E. J.; Gray, C. L.; Corralez, D. S.; Robinson, C. A.; Soderlund, K. M.
2005-12-01
One persistent difficulty many astronomy students face is the lack of 3- dimensional mental model of the systems being studied, in particular the Sun-Earth-Moon system. Students without such a mental model can have a very hard time conceptualizing the geometric relationships that cause, for example, the cycle of lunar phases or the pattern of seasons. The GeoWall is a recently developed and affordable projection mechanism for three-dimensional stereo visualization which is becoming a popular tool in classrooms and research labs for use in geology classes, but as yet very little work has been done involving the GeoWall for astronomy classes. We present results from a large study involving over 1000 students of varied backgrounds: some students were tested at the University of Texas at El Paso, a large public university on the US-Mexico border and other students were from the Florida Institute of Technology, a small, private, technical school in Melbourne Florida. We wrote a lecture tutorial-style lab to go along with a GeoWall 3D visual of the Earth-Moon system and tested the students before and after with several diagnostics. Students were given pre and post tests using the Lunar Phase Concept Inventory (LPCI) as well as a separate evaluation written specifically for this project. We found the lab useful for both populations of students, but not equally effective for all. We discuss reactions from the students and their improvement, as well as whether the students are able to correctly assess the usefullness of the project for their own learning.
Application of a space station to communications satellites
NASA Technical Reports Server (NTRS)
Ramler, J. R.
1983-01-01
The economic benefits of a space station relative to communications satellites are discussed in terms of technology experiments, spacecraft checkout, repair, servicing, and refurbishment (RSR), and mating an OTV with satellites for boost to GEO. The zero gravity, vacuum conditions, and atmosphere free long ranges are environmental features that can be used for testing large, flexible antennas and laser communications devices. Some resistance might be encountered to checkout in LEO due to the substantial success of launches to GEO without LEO checkout. However, new generations of larger, more complex satellites may warrant the presence of a space station to verify performance of new spacecraft. One RSR positive aspect for a space station is as a storage site for propellant, as well as for reusable OTV booster engines. Also, the space station can serve as a base for manned or unmanned repair spacecraft which will travel to GEO to fix malfunctions in geostationary satellites.
Satellite radar altimetry over ice. Volume 4: Users' guide for Antarctica elevation data from Seasat
NASA Technical Reports Server (NTRS)
Zwally, H. Jay; Major, Judith A.; Brenner, Anita C.; Bindschadler, Robert A.; Martin, Thomas V.
1990-01-01
A gridded surface-elevation data set and a geo-referenced data base for the Seasat radar altimeter data over Greenland are described. This is a user guide to accompany the data provided to data centers and other users. The grid points are on a polar stereographic projection with a nominal spacing of 20 km. The gridded elevations are derived from the elevation data in the geo-referenced data base by a weighted fitting of a surface in the neighborhood of each grid point. The gridded elevations are useful for the creating of large-scale contour maps, and the geo-referenced data base is useful for regridding, creating smaller-scale contour maps, and examinating individual elevation measurements in specific geographic areas. Tape formats are described, and a FORTRAN program for reading the data tape is listed and provided on the tape.
Extracting and Comparing Places Using Geo-Social Media
NASA Astrophysics Data System (ADS)
Ostermann, F. O.; Huang, H.; Andrienko, G.; Andrienko, N.; Capineri, C.; Farkas, K.; Purves, R. S.
2015-08-01
Increasing availability of Geo-Social Media (e.g. Facebook, Foursquare and Flickr) has led to the accumulation of large volumes of social media data. These data, especially geotagged ones, contain information about perception of and experiences in various environments. Harnessing these data can be used to provide a better understanding of the semantics of places. We are interested in the similarities or differences between different Geo-Social Media in the description of places. This extended abstract presents the results of a first step towards a more in-depth study of semantic similarity of places. Particularly, we took places extracted through spatio-temporal clustering from one data source (Twitter) and examined whether their structure is reflected semantically in another data set (Flickr). Based on that, we analyse how the semantic similarity between places varies over space and scale, and how Tobler's first law of geography holds with regards to scale and places.
CubeSat Integration into the Space Situational Awareness Architecture
NASA Astrophysics Data System (ADS)
Morris, K.; Wolfson, M.; Brown, J.
2013-09-01
Lockheed Martin Space Systems Company has recently been involved in developing GEO Space Situational Awareness architectures, which allows insights into how cubesats can augment the current national systems. One hole that was identified in the current architecture is the need for timelier metric track observations to aid in the chain of custody. Obtaining observations of objects at GEO can be supported by CubeSats. These types of small satellites are increasing being built and flown by government agencies like NASA and SMDC. CubeSats are generally mass and power constrained allowing for only small payloads that cannot typically mimic traditional flight capability. CubeSats do not have a high reliability and care must be taken when choosing mission orbits to prevent creating more debris. However, due to the low costs, short development timelines, and available hardware, CubeSats can supply very valuable benefits to these complex missions, affordably. For example, utilizing CubeSats for advanced focal plane demonstrations to support technology insertion into the next generation situational awareness sensors can help to lower risks before the complex sensors are developed. CubeSats can augment the planned ground and space based assets by creating larger constellations with more access to areas of interest. To aid in maintaining custody of objects, a CubeSat constellation at 500 km above GEO would provide increased point of light tracking that can augment the ground SSA assets. Key features of the Cubesat include a small visible camera looking along the GEO belt, a small propulsion system that allows phasing between CubeSats, and an image processor to reduce the data sent to the ground. An elegant communications network will also be used to provide commands to and data from multiple CubeSats. Additional CubeSats can be deployed on GSO launches or through ride shares to GEO, replenishing or adding to the constellation with each launch. Each CubeSat would take images of the GEO belt, process out the stars, and then downlink the data to the ground. This data can then be combined with the existing metric track data to enhance the coverage and timeliness. With the current capability of CubeSats and their payloads, along with the launch constraints, the near term focus is to integrate into existing architectures by reducing technology risks, understanding unique phenomenology, and augment mission collection capability. Understanding the near term benefits of utilizing CubeSats will better inform the SSA mission developers how to integrate CubeSats into the next generation of architectures from the start.
Alternative and cost-effective bridge approach slabs.
DOT National Transportation Integrated Search
2010-10-01
The primary objectives of the proposed project are to investigate the causes for any bumps at the end of the bridge approach slab : and to develop remedial measures or alternative designs for a replacement. It is clear that the problem stems from geo...
Encoding of Geological knowledge in the GeoPiemonte Map Data Base
NASA Astrophysics Data System (ADS)
Piana, Fabrizio; Lombardo, Vincenzo; Mimmo, Dario; Barale, Luca; Irace, Andrea; Mulazzano, Elia
2017-04-01
In modern digital geological maps and geo-database, namely those devoted to interactive WebGIS services, there is the need to make explicit the geological assumptions in the process of the design and compilation of the Map Geodatabase. The Geodatabase of the Piemonte Geological Map, which consists of several thousands of Geologic Units and Geologic Structures, was designed in a way suitable for linking the knowledge of the geological domain at hand to more general levels of knowledge, represented in existing Earth Sciences ontologies and in a domain ontology (OntoGeonous), specifically designed for the project, though with a wide applicability in mind. The Geologic Units and Geologic Structures of the GeoPiemonte Map have been spatially correlated through the whole region, referring to a non-formal hierarchical scheme, which gives the parental relations between several orders of Geologic Units, putting them in relations with some main Geologic Events. The scheme reports the subdivisions we did on the Alps-Apennines orogenic belt (which constitutes the Piemonte geological framework) on which the architecture of the GeoDB relied. This contribution describes how the two different knowledge levels (specific domain vs. general knowledge) are assimilated within the GeoPiemonte informative system, providing relations between the contents of the geodatabase and the encoded concepts of the reference ontologies. Initiatives such as GeoScience Markup Language (GeoSciML 4.01, 2016 (1) and INSPIRE "Data Specification on Geology" (an operative simplification of GeoSciML, last version is 3.0, 2013) (2), as well as the recent terminological shepherding of the Geoscience Terminology Working Group (GTWG), provided us the authoritative standard geological source for knowledge encoding. Consistency and interoperability of geological data were thus sought, by classifying geologic features in an ontology-driven Data Model, while objects were described using GeoSciML controlled vocabularies and concepts derived from NASA SWEET ontology (3) (4) (5). At the state of the art the GeoPiemonte Map informative system is thus suitable for integration in trans-national Data Infrastructures and/or WebMap Services that require interoperability and harmonised semantic approaches. References (1)http://www.geosciml.org/geosciml/4.0/documentation/html/ - GeoSciML Data Model - (2)http://inspire.ec.europa.eu/documents/Data_Specifications/INSPIRE_DataSpecification_GE_v3.0.pdf - INSPIRE DS Technical Guidelines (3)http://resource.geosciml.org/vocabulary/cgi/201211/simplelithology.html (4)http://resource.geosciml.org/vocabulary/cgi/ - CGI GTWG controlled vocabularies repository (5) SWEET (Semantic Web for Earth and Environmental Terminology), http://www.sweet.jpl.nasa.govAppel Piana et al., 2017a. Geology of Piemonte Region (NW Italy, Alps-Apennines junction zone). Journal of Maps, in press. Piana et al., 2017b. The Geodatabase of the Piemonte Geological Map: conceptual design for knowledge encoding. ROL Soc. Geol. It., in press.
NASA Astrophysics Data System (ADS)
Esch, Thomas; Asamer, Hubert; Hirner, Andreas; Marconcini, Mattia; Metz, Annekatrin; Uereyen, Soner; Zeidler, Julian; Boettcher, Martin; Permana, Hans; Boissier, Enguerran; Mathot, Emmanuel; Soukop, Tomas; Balhar, Jakub; Svaton, Vaclav; Kuchar, Stepan
2017-04-01
The Sentinel fleet will provide a so-far unique coverage with Earth Observation (EO) data and therewith new opportunities for the implementation of methodologies to generate innovative geo-information products and services supporting the SDG targets. It is here where the TEP Urban project is supposed to initiate a step change by providing an open and participatory platform that allows any interested user to easily exploit large-volume EO data pools, in particular those of the European Sentinel and the US Landsat missions, and derive thematic geo-information, metrics and indicators related to the status and development of the built environment. Key component of TEP Urban initiative is the implementation of a web-based platform (https://urban-tep.eo.esa.int) employing distributed high-level computing infrastructures and providing key functionalities for i) high-performance access to satellite imagery and other data sources such as statistics or topographic data, ii) state-of-the-art pre-processing, analysis, and visualization techniques, iii) customized development and dissemination of algorithms, products and services, and iv) networking and communication. This contribution introduces the main facts about the TEP Urban platform, including a description of the general objectives, the platform systems design and functionalities, and the available portfolio of products and services that can directly serve the global provision of indicators for SDG targets, in particular related to SDG 11.
Geohazard and geological condition overview of Sekeloa-Bojongkoneng, Bandung, West Java-Indonesia
NASA Astrophysics Data System (ADS)
Hadian, Mohamad Sapari D.; Azzy, Fikri Noor; Sophian, R. Irvan
2016-05-01
Bandung is a densely populated and rapidly growing city, especially in the Northern Area, with many rivers flowing through it. Infrastructure development if not taken into account the geo hazard potential of the river can cause disaster to occur resulting in damages and casualties. The inundation named "Cileuncang Flood" periodically occurred in the rainy season. Landslide disaster also occurred in 2015 at Mekarsaluyu, Cimenyan and Bukit Dago Selatan. This study explores the phenomena that occurred in the region. The research objectives are to: identify geological conditions contributing to geo hazard, conduct geo hazard assessment in the area and recommend mitigation activities. Research area ranges from Sekeloa to Bojongkoneng, where there are three rivers: Cirapohan, Cidurian, and Cilimus. The research method used mixed method, field observation and desk study (secondary data). Geospatial data and geological field observation was conducted. Lithology layers coring well data was used to determine the detailed geological condition and characteristic. Research results show geological condition that can trigger disaster. There are some locations, which have disasters in the past, this occurrence is connected with geological conditions to determine the potential disaster that may occur in the future. The first site is located on the western part of the Cidurian river consisted of Cikidang Formation. Geo hazard that occurred in this zone is flood. Second site is located on the eastern part of the Cidurian river, has the presence of volcanic eruption product. Geo hazard that can potentially occur in this zone is a landslide. The city stakeholder needs to conduct structural and nonstructural mitigation activities to reduce the risks.
EPOS-WP16: A Platform for European Multi-scale Laboratories
NASA Astrophysics Data System (ADS)
Spiers, Chris; Drury, Martyn; Kan-Parker, Mirjam; Lange, Otto; Willingshofer, Ernst; Funiciello, Francesca; Rosenau, Matthias; Scarlato, Piergiorgio; Sagnotti, Leonardo; W16 Participants
2016-04-01
The participant countries in EPOS embody a wide range of world-class laboratory infrastructures ranging from high temperature and pressure experimental facilities, to electron microscopy, micro-beam analysis, analogue modeling and paleomagnetic laboratories. Most data produced by the various laboratory centres and networks are presently available only in limited "final form" in publications. As such many data remain inaccessible and/or poorly preserved. However, the data produced at the participating laboratories are crucial to serving society's need for geo-resources exploration and for protection against geo-hazards. Indeed, to model resource formation and system behaviour during exploitation, we need an understanding from the molecular to the continental scale, based on experimental data. This contribution will describe the work plans that the laboratories community in Europe is making, in the context of EPOS. The main objectives are: - To collect and harmonize available and emerging laboratory data on the properties and processes controlling rock system behaviour at multiple scales, in order to generate products accessible and interoperable through services for supporting research activities. - To co-ordinate the development, integration and trans-national usage of the major solid Earth Science laboratory centres and specialist networks. The length scales encompassed by the infrastructures included range from the nano- and micrometer levels (electron microscopy and micro-beam analysis) to the scale of experiments on centimetre sized samples, and to analogue model experiments simulating the reservoir scale, the basin scale and the plate scale. - To provide products and services supporting research into Geo-resources and Geo-storage, Geo-hazards and Earth System Evolution.
Geostationary platform systems concepts definition study. Volume 2: Technical, book 2
NASA Technical Reports Server (NTRS)
1980-01-01
A selected concept for a geostationary platform is defined in sufficient detail to identify requirements for supporting research and technology, space demonstrations, GFE interfaces, costs, and schedules. This system consists of six platforms in geostationary orbit (GEO) over the Western Hemisphere and six over the Atlantic, to satisfy the total payload set associated with the nominal traffic model. Each platform is delivered to low Earth orbit (LEO) in a single shuttle flight, already mated to its LEO to GEO transfer vehicle and ready for deployment and transfer to GEO. An alternative concept is looked at briefly for comparison of configuration and technology requirements. This alternative consists of two large platforms, one over the Western Hemisphere consisting of three docked modules, and one over the Atlantic (two docked modules), to satisfy a high traffic model. The modules are full length orbiter cargo bay payloads, mated at LEO to orbital transfer vehicles (OTVs) delivered in other shuttle flights, for transfer to GEO, rendezvous, and docking. A preliminary feasibility study of an experimental platform is also performed to demonstrate communications and platform technologies required for the operational platforms of the 1990s.
Kim, Ghangho; Kim, Chongwon; Kee, Changdon
2015-04-01
A practical algorithm is proposed for determining the orbit of a geostationary orbit (GEO) satellite using single-epoch measurements from a Global Positioning System (GPS) receiver under the sparse visibility of the GPS satellites. The algorithm uses three components of a state vector to determine the satellite's state, even when it is impossible to apply the classical single-point solutions (SPS). Through consideration of the characteristics of the GEO orbital elements and GPS measurements, the components of the state vector are reduced to three. However, the algorithm remains sufficiently accurate for a GEO satellite. The developed algorithm was tested on simulated measurements from two or three GPS satellites, and the calculated maximum position error was found to be less than approximately 40 km or even several kilometers within the geometric range, even when the classical SPS solution was unattainable. In addition, extended Kalman filter (EKF) tests of a GEO satellite with the estimated initial state were performed to validate the algorithm. In the EKF, a reliable dynamic model was adapted to reduce the probability of divergence that can be caused by large errors in the initial state.
Coarse Initial Orbit Determination for a Geostationary Satellite Using Single-Epoch GPS Measurements
Kim, Ghangho; Kim, Chongwon; Kee, Changdon
2015-01-01
A practical algorithm is proposed for determining the orbit of a geostationary orbit (GEO) satellite using single-epoch measurements from a Global Positioning System (GPS) receiver under the sparse visibility of the GPS satellites. The algorithm uses three components of a state vector to determine the satellite’s state, even when it is impossible to apply the classical single-point solutions (SPS). Through consideration of the characteristics of the GEO orbital elements and GPS measurements, the components of the state vector are reduced to three. However, the algorithm remains sufficiently accurate for a GEO satellite. The developed algorithm was tested on simulated measurements from two or three GPS satellites, and the calculated maximum position error was found to be less than approximately 40 km or even several kilometers within the geometric range, even when the classical SPS solution was unattainable. In addition, extended Kalman filter (EKF) tests of a GEO satellite with the estimated initial state were performed to validate the algorithm. In the EKF, a reliable dynamic model was adapted to reduce the probability of divergence that can be caused by large errors in the initial state. PMID:25835299
OntoFire: an ontology-based geo-portal for wildfires
NASA Astrophysics Data System (ADS)
Kalabokidis, K.; Athanasis, N.; Vaitis, M.
2011-12-01
With the proliferation of the geospatial technologies on the Internet, the role of geo-portals (i.e. gateways to Spatial Data Infrastructures) in the area of wildfires management emerges. However, keyword-based techniques often frustrate users when looking for data of interest in geo-portal environments, while little attention has been paid to shift from the conventional keyword-based to navigation-based mechanisms. The presented OntoFire system is an ontology-based geo-portal about wildfires. Through the proposed navigation mechanisms, the relationships between the data can be discovered, which would otherwise not be possible when using conventional querying techniques alone. End users can use the browsing interface to find resources of interest by using the navigation mechanisms provided. Data providers can use the publishing interface to submit new metadata, modify metadata or removing metadata in/from the catalogue. The proposed approach can improve the discovery of valuable information that is necessary to set priorities for disaster mitigation and prevention strategies. OntoFire aspires to be a focal point of integration and management of a very large amount of information, contributing in this way to the dissemination of knowledge and to the preparedness of the operational stakeholders.
Searching for Optically Faint GEO Debris
NASA Technical Reports Server (NTRS)
Seitzer, Patrick; Lederer, Susan M.; Abercromby, Kira J.; Barker, Edwin S.; Burkhardt, Andrew; Cowardin, Heather; Krisko, Paula; Silha, Jiri
2012-01-01
We report on results from a search for optically faint debris (defined as R > 20th magnitude, or smaller than 10 cm assuming an albedo of 0.175)) at geosynchronous orbit (GEO) using the 6.5-m Magellan telescope "Walter Baade" at Las Campanas Observatory in Chile. Our goal is to characterize the brightness distribution of debris to the faintest limiting magnitude possible. Our data was obtained during 6 hours of observing time during the photometric nights of 26 and 27 March 2011 with the IMACS f/2 instrument, which has a field of view (fov) of 0.5 degrees in diameter. All observations were obtained through a Sloan r filter, and calibrated by observations of Landolt standard stars. Our primary objective was to search for optically faint objects from one of the few known fragmentations at GEO: the Titan 3C Transtage (1968-081) fragmentation in 1992. Eight debris pieces and the parent rocket body are in the Space Surveillance Network public catalog. We successfully tracked two cataloged pieces of Titan debris with the 6.5-m telescope, followed by a survey for unknown objects on similar orbits but with different mean anomalies. To establish the bright end of the debris population, calibrated observations were acquired on the same field centers, telescope rates, and time period with a similar filter on the 0.6-m MODEST (Michigan Orbital DEbris Survey Telescope), located 100 km to the south of Magellan at Cerro Tololo Inter-American Observatory, Chile. We will show the calibrated brightness distributions from both telescopes, and compare the observed brightness distributions with that predicted for various population models of debris of different sizes.
NASA Astrophysics Data System (ADS)
Shepherd, Adam; Arko, Robert; Krisnadhi, Adila; Hitzler, Pascal; Janowicz, Krzysztof; Chandler, Cyndy; Narock, Tom; Cheatham, Michelle; Schildhauer, Mark; Jones, Matt; Raymond, Lisa; Mickle, Audrey; Finin, Tim; Fils, Doug; Carbotte, Suzanne; Lehnert, Kerstin
2015-04-01
Integrating datasets for new use cases is one of the common drivers for adopting semantic web technologies. Even though linked data principles enables this type of activity over time, the task of reconciling new ontological commitments for newer use cases can be daunting. This situation was faced by the Biological and Chemical Oceanography Data Management Office (BCO-DMO) as it sought to integrate its existing linked data with other data repositories to address newer scientific use cases as a partner in the GeoLink Project. To achieve a successful integration with other GeoLink partners, BCO-DMO's metadata would need to be described using the new ontologies developed by the GeoLink partners - a situation that could impact semantic inferencing, pre-existing software and external users of BCO-DMO's linked data. This presentation describes the process of how GeoLink is bridging the gap between local, pre-existing ontologies to achieve scientific metadata integration for all its partners through the use of ontology design patterns. GeoLink, an NSF EarthCube Building Block, brings together experts from the geosciences, computer science, and library science in an effort to improve discovery and reuse of data and knowledge. Its participating repositories include content from field expeditions, laboratory analyses, journal publications, conference presentations, theses/reports, and funding awards that span scientific studies from marine geology to marine ecology and biogeochemistry to paleoclimatology. GeoLink's outcomes include a set of reusable ontology design patterns (ODPs) that describe core geoscience concepts, a network of Linked Data published by participating repositories using those ODPs, and tools to facilitate discovery of related content in multiple repositories.
NASA Astrophysics Data System (ADS)
Schönbrodt, S.; Behrens, T.; Bieger, K.; Ehret, D.; Frei, M.; Hörmann, G.; Seeber, C.; Schleier, M.; Schmalz, B.; Fohrer, N.; Kaufmann, H.; King, L.; Rohn, J.; Subklew, G.; Xiang, W.
2012-04-01
The river impoundment by The Three Gorges Dam leads to resettlement and land reclamation on steep slopes. As a consequence, ecosystem changes such as soil erosion, mass movements, and diffuse sediment and matter fluxes are widely expected to increase rapidly. In order to assess and analyse those ecosystem changes, the German-Chinese joint research project YANGTZE-GEO was set up in 2008. Within the framework of YANGTZE-GEO five German universities (Tuebingen, Erlangen, Giessen, Kiel, Potsdam) conducted studies on soil erosion, mass movements, diffuse matter inputs, and land use change and vulnerability in close collaboration with Chinese scientists. The Chinese partners and institutions are according to their alphabetic order of hometown the Chinese Research Academy of Environmental Sciences (CRAES; Beijing), the Standing Office of the State Council Three Gorges Project Construction Committee (Beijing), the National Climate Centre (NCC) of the China Meteorological Administration (CMA; Beijing), the Aero Geophysical Survey and Remote Sensing for Land and Resources (AES; Beijing), the Nanjing University, the CAS Institute of Soil Science (Nanjing), the Nanjing Institute of Geography and Limnology at CAS (NIGLAS; Nanjing), the China University of Geosciences (CUG; Wuhan), the CAS Institute of Hydrobiology (Wuhan), and the China Three Gorges University (Yichang). The overall aim of YANGTZE-GEO is the development of a risk assessment and forecasting system to locate high risk areas using GIS-based erosion modelling, data mining tools for terrace condition analysis and landslide recognition, eco-hydrological modelling for diffuse matter inputs, and state-of-the-art remote sensing to assess the landscape's vulnerability. Furthermore, the project aims at the recommendation of sustainable land management systems. YANGTZE-GEO showed the relevance of such research and crucially contributes to the understanding of the dimension and dynamics of the ecological consequences of large dam projects.
CTFS-ForestGEO: a worldwide network monitoring forests in an era of global change.
Anderson-Teixeira, Kristina J; Davies, Stuart J; Bennett, Amy C; Gonzalez-Akre, Erika B; Muller-Landau, Helene C; Wright, S Joseph; Abu Salim, Kamariah; Almeyda Zambrano, Angélica M; Alonso, Alfonso; Baltzer, Jennifer L; Basset, Yves; Bourg, Norman A; Broadbent, Eben N; Brockelman, Warren Y; Bunyavejchewin, Sarayudh; Burslem, David F R P; Butt, Nathalie; Cao, Min; Cardenas, Dairon; Chuyong, George B; Clay, Keith; Cordell, Susan; Dattaraja, Handanakere S; Deng, Xiaobao; Detto, Matteo; Du, Xiaojun; Duque, Alvaro; Erikson, David L; Ewango, Corneille E N; Fischer, Gunter A; Fletcher, Christine; Foster, Robin B; Giardina, Christian P; Gilbert, Gregory S; Gunatilleke, Nimal; Gunatilleke, Savitri; Hao, Zhanqing; Hargrove, William W; Hart, Terese B; Hau, Billy C H; He, Fangliang; Hoffman, Forrest M; Howe, Robert W; Hubbell, Stephen P; Inman-Narahari, Faith M; Jansen, Patrick A; Jiang, Mingxi; Johnson, Daniel J; Kanzaki, Mamoru; Kassim, Abdul Rahman; Kenfack, David; Kibet, Staline; Kinnaird, Margaret F; Korte, Lisa; Kral, Kamil; Kumar, Jitendra; Larson, Andrew J; Li, Yide; Li, Xiankun; Liu, Shirong; Lum, Shawn K Y; Lutz, James A; Ma, Keping; Maddalena, Damian M; Makana, Jean-Remy; Malhi, Yadvinder; Marthews, Toby; Mat Serudin, Rafizah; McMahon, Sean M; McShea, William J; Memiaghe, Hervé R; Mi, Xiangcheng; Mizuno, Takashi; Morecroft, Michael; Myers, Jonathan A; Novotny, Vojtech; de Oliveira, Alexandre A; Ong, Perry S; Orwig, David A; Ostertag, Rebecca; den Ouden, Jan; Parker, Geoffrey G; Phillips, Richard P; Sack, Lawren; Sainge, Moses N; Sang, Weiguo; Sri-Ngernyuang, Kriangsak; Sukumar, Raman; Sun, I-Fang; Sungpalee, Witchaphart; Suresh, Hebbalalu Sathyanarayana; Tan, Sylvester; Thomas, Sean C; Thomas, Duncan W; Thompson, Jill; Turner, Benjamin L; Uriarte, Maria; Valencia, Renato; Vallejo, Marta I; Vicentini, Alberto; Vrška, Tomáš; Wang, Xihua; Wang, Xugao; Weiblen, George; Wolf, Amy; Xu, Han; Yap, Sandra; Zimmerman, Jess
2015-02-01
Global change is impacting forests worldwide, threatening biodiversity and ecosystem services including climate regulation. Understanding how forests respond is critical to forest conservation and climate protection. This review describes an international network of 59 long-term forest dynamics research sites (CTFS-ForestGEO) useful for characterizing forest responses to global change. Within very large plots (median size 25 ha), all stems ≥ 1 cm diameter are identified to species, mapped, and regularly recensused according to standardized protocols. CTFS-ForestGEO spans 25 °S-61 °N latitude, is generally representative of the range of bioclimatic, edaphic, and topographic conditions experienced by forests worldwide, and is the only forest monitoring network that applies a standardized protocol to each of the world's major forest biomes. Supplementary standardized measurements at subsets of the sites provide additional information on plants, animals, and ecosystem and environmental variables. CTFS-ForestGEO sites are experiencing multifaceted anthropogenic global change pressures including warming (average 0.61 °C), changes in precipitation (up to ± 30% change), atmospheric deposition of nitrogen and sulfur compounds (up to 3.8 g N m(-2) yr(-1) and 3.1 g S m(-2) yr(-1)), and forest fragmentation in the surrounding landscape (up to 88% reduced tree cover within 5 km). The broad suite of measurements made at CTFS-ForestGEO sites makes it possible to investigate the complex ways in which global change is impacting forest dynamics. Ongoing research across the CTFS-ForestGEO network is yielding insights into how and why the forests are changing, and continued monitoring will provide vital contributions to understanding worldwide forest diversity and dynamics in an era of global change. © 2014 John Wiley & Sons Ltd.
Design and Implementation of a New System for Large Bridge Monitoring—GeoSHM
Xie, Yilin; Ince, Sean; Ye, Jun; Bhatia, Paul
2018-01-01
Structural Health Monitoring (SHM) is a relatively new branch of civil engineering that focuses on assessing the health status of infrastructure, such as long-span bridges. Using a broad range of in-situ monitoring instruments, the purpose of the SHM is to help engineers understand the behaviour of structures, ensuring their structural integrity and the safety of the public. Under the Integrated Applications Promotion (IAP) scheme of the European Space Agency (ESA), a feasibility study (FS) project that used the Global Navigation Satellite Systems (GNSS) and Earth Observation (EO) for Structural Health Monitoring of Long-span Bridges (GeoSHM) was initiated in 2013. The GeoSHM FS Project was led by University of Nottingham and the Forth Road Bridge (Scotland, UK), which is a 2.5 km long suspension bridge across the Firth of Forth connecting Edinburgh and the Northern part of Scotland, was selected as the test structure for the GeoSHM FS project. Initial results have shown the significant potential of the GNSS and EO technologies. With these successes, the FS project was further extended to the demonstration stage, which is called the GeoSHM Demo project where two other long-span bridges in China were included as test structures. Led by UbiPOS UK Ltd. (Nottingham, UK), a Nottingham Hi-tech company, this stage focuses on addressing limitations identified during the feasibility study and developing an innovative data strategy to process, store, and interpret monitoring data. This paper will present an overview of the motivation and challenges of the GeoSHM Demo Project, a description of the software and hardware architecture and a discussion of some primary results that were obtained in the last three years. PMID:29510534
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chen Yongqing, E-mail: ydonglai@mail.cgs.gov.cn; Zhao Pengda; Chen Jianguo
2001-03-15
A number of large and giant ore deposits have been discovered within the relatively small areas of lithospheric structure anomalies, including various boundary zones of tectonic plates. The regions have become the well-known intercontinental ore-forming belts, such as the circum-Pacific gold-copper, copper-molybdenum, and tungsten-tin metallogenic belts. These belts are typical geological anomalous areas. An investigation into the hydrothermal ore deposits in different regions in the former Soviet Union illustrated that the geologic structures of ore fields of almost all major commercial deposits have distinct features compared with the neighboring areas. These areas with distinct features are defined as geo-anomalies. Amore » geo-anomaly refers to such a geologic body or a combination of bodies that their composition, texture-structure, and genesis are significantly different from those of their surroundings. A geo-anomaly unit (GU) is an area containing distinct features that can be delineated with integrated ore-forming information using computer techniques on the basis of the geo-anomaly concept. Herein, the GU concept is illustrated by a case study of delineating the gold ore targets in the western Shandong uplift terrain, eastern China. It includes: (1) analyses of gold ore-forming factors; (2) compilation of normalized regional geochemical map and extraction of geochemical anomalies; (3) compilation of gravitational and aeromagnetic tectonic skeleton map and extraction of gravitational and aeromagnetic anomalies; (4) extraction of circular and linear anomalies from remote-sensing Landsat TM images; (5) establishment of a geo-anomaly conceptual model associated with known gold mineralization; (6) establishment of gold ore-forming favorability by computing techniques; and (7) delineation and assessment of ore-forming units. The units with high favorability are suggested as ore targets.« less
NASA Astrophysics Data System (ADS)
Liebscher, A.; Scheck-Wenderoth, M.; GeoEn Research Group
2012-04-01
Axel Liebscher1, Magdalena Scheck-Wenderoth1 and the GeoEn Research Group1, 2,3 1 Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences, Potsdam, Germany 2 University Potsdam, Germany 3 BTU Cottbus, Germany One of the pressing challenges for the 21st century is a secure, sustainable and economical energy supply at simultaneous mitigation of its climate impact. Besides a switch to renewable energy resources, the exploration and exploitation of new, unconventional energy resources will play a major role as will the further use of fossil fuels. With the switch to renewable energies the question of geological energy storage will become an important topic whereas further use of fossil fuels requires strategies like CCS to reduce its negative climate impacts. These different aspects of geo-energy make complementary or competitive demands on the subsurface and its use. It is therefore essential to treat the subsurface as a geo-resource of its own right. So far, geo-resource related research has often focused on specific resource systems, e.g. ore forming systems, hydrocarbon systems or geothermal systems, providing results largely applicable only to the restricted range of physicochemical properties of the respective geo-resource systems. However, with the increasing use of the subsurface as important geo-resource, the different geo-resource systems tend to overlap and interact and also become much more complex due to the additional use or presence of artificial and technical matter, as is the case in geological CO2 storage. On the other hand, the combined use of the subsurface for different purposes may also create synergetic effects. GeoEn is a joint research project explicitly addressing the fundamental questions related to the sustainable and holistic use of the geo-resource subsurface with a special focus on geo-energy. Project partners are the German Research Centre for Geosciences (GFZ), the University of Potsdam (UP) and the Brandenburg University of Technology (BTU). GeoEn research addresses CO2 capture, transport and utilization, CO2 storage, the unconventional energy resource shale gas and geothermal technologies. These four core topics are studied in an integrated approach using the synergy of cross-cutting themes. The latter encompass new exploration and reservoir technologies as well as innovative monitoring methods, both complemented by numerical simulations of the relevant processes including flow dynamics or heat transfer in the subsurface and along the technological process chains. Accordingly, synergies derived from the cross-cutting topics improve both methodological development applicable in equal measure to the utilization of geothermal energy and of shale gas as well as to the use and monitoring of CO2 storage. Complementary, new modelling approaches are developed that allow the simulation of involved processes to predict the occurrence and physical properties of potential reservoirs and the changes that may be induced by their utilization. We present first results with respect to exploration strategies, monitoring technologies and modeling approaches for the pilot storage site for CO2 in Ketzin and the geothermal research platform Groß-Schönebeck, where the respective technologies are tested and monitored.
NASA Astrophysics Data System (ADS)
Aleksandrova, A. G.; Chuvashov, I. N.; Bordovitsyna, T. V.
2011-07-01
The results of investigations of the instability of orbits in the GEO are presentеd. Average parameter MEGNO as main indicator of chaotic state has been used. The parameter is computed by combined numerical integration of equations of the motion, equations in variation and equations of MEGNO parameters. The results have been obtained using software package "Numerical model of the systems artificial satellite motion", implemented on the cluster "Skiff Cyberia".
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Yanbin; Shen, Guoyin
2014-12-23
Here, we review recent progress in studying silicate, carbonate, and metallic liquids of geological and geophysical importance at high pressure and temperature, using the large-volume high-pressure devices at the third-generation synchrotron facility of the Advanced Photon Source, Argonne National Laboratory. These integrated high-pressure facilities now offer a unique combination of experimental techniques that allow researchers to investigate structure, density, elasticity, viscosity, and interfacial tension of geo-liquids under high pressure, in a coordinated and systematic fashion. Moreover, we describe experimental techniques, along with scientific highlights. Future developments are also discussed.
Modeling streams and hydrogeomorphic attributes in Oregon from digital and field data
Sharon E. Clarke; Kelly M. Burnett; Daniel J. Miller
2008-01-01
Managers, regulators, and researchers of aquatic ecosystems are increasingly pressed to consider large areas. However, accurate stream maps with geo-referenced attributes are uncommon over relevant spatial extents. Field inventories provide high-quality data, particularly for habitat characteristics at fine spatial resolutions (e.g., large wood), but are costly and so...
Geothermal Technologies | NREL
clean, renewable, domestic power source for the United States. Photo of a geothermal power plant in a technical barriers. GeoVision Study Photo of large gears on a drilling apparatus Technology Innovation We're of a woman in a hard hat with a large, drilling apparatus behind her in a grassy field Partnerships
Space Spider - A concept for fabrication of large structures
NASA Technical Reports Server (NTRS)
Britton, W. R.; Johnston, J. D.
1978-01-01
The Space Spider concept for the automated fabrication of large space structures involves a specialized machine which roll-forms thin gauge material such as aluminum and develops continuous spiral structures with radial struts to sizes of 600-1,000 feet in diameter by 15 feet deep. This concept allows the machine and raw material to be integrated using the Orbiter capabilities, then boosting the rigid system to geosynchronous equatorial orbit (GEO) without high sensitivity to acceleration forces. As a teleoperator controlled device having repetitive operations, the fabrication process can be monitored and verified from a ground-based station without astronaut involvement in GEO. The resultant structure will be useful as an intermediate size platform or as a structural element to be used with other elements such as the space-fabricated beams or composite nested tubes.
Large-Scale Transport Responses to Tropospheric Circulation Changes Using GEOS-5
NASA Technical Reports Server (NTRS)
Orbe, Clara; Molod, Andrea; Arnold, Nathan; Waugh, Darryn W.; Yang, Huang
2017-01-01
The mean age since air was last at the Northern Hemisphere midlatitude surface is a fundamental property of tropospheric transport. Recent comparisons among chemistry climate models, however, reveal that there are large differences in the mean age among models and that these differences are most likely related to differences in tropical (parameterized) convection. Here we use aquaplanet simulations of the Goddard Earth Observing System Model Version 5 (GEOS-5) to explore the sensitivity of the mean age to changes in the tropical circulation. Tropical circulation changes are forced by prescribed localized off-equatorial warm sea surface temperature anomalies that (qualitatively) reproduce the convection and circulation differences among the comprehensive models. Idealized chemical species subject to prescribed OH loss are also integrated in parallel in order to illustrate the impact of tropical transport changes on interhemispheric constituent transport.
Evaluation of remote sensing aerial systems in existing transportation practices, phase II.
DOT National Transportation Integrated Search
2011-06-01
A low-cost aerial platform represents a flexible tool for acquiring high-resolution images for ground areas of interest. The geo-referencing of objects within these images could benefit civil engineers in a variety of research areas including, but no...
Paradise: A Parallel Information System for EOSDIS
NASA Technical Reports Server (NTRS)
DeWitt, David
1996-01-01
The Paradise project was begun-in 1993 in order to explore the application of the parallel and object-oriented database system technology developed as a part of the Gamma, Exodus. and Shore projects to the design and development of a scaleable, geo-spatial database system for storing both massive spatial and satellite image data sets. Paradise is based on an object-relational data model. In addition to the standard attribute types such as integers, floats, strings and time, Paradise also provides a set of and multimedia data types, designed to facilitate the storage and querying of complex spatial and multimedia data sets. An individual tuple can contain any combination of this rich set of data types. For example, in the EOSDIS context, a tuple might mix terrain and map data for an area along with the latest satellite weather photo of the area. The use of a geo-spatial metaphor simplifies the task of fusing disparate forms of data from multiple data sources including text, image, map, and video data sets.
NASA Technical Reports Server (NTRS)
Woeppel, Eric A.; Balsamo, James M.; Fischer, Karl J.; East, Matthew J.; Styborski, Jeremy A.; Roche, Christopher A.; Ott, Mackenzie D.; Scorza, Matthew J.; Doherty, Christopher D.; Trovato, Andrew J.;
2014-01-01
This paper describes a microsatellite spacecraft with supporting mission profile and architecture, designed to enable preliminary in-situ characterization of a significant number of Near Earth Objects (NEOs) at reasonably low cost. The spacecraft will be referred to as the NEO-Scout. NEO-Scout spacecraft are to be placed in Geosynchronous Equatorial Orbit (GEO), cis-lunar space, or on earth escape trajectories as secondary payloads on launch vehicles headed for GEO or beyond, and will begin their mission after deployment from the launcher. A distinguishing key feature of the NEO-Scout system is to design the spacecraft and mission timeline so as to enable rendezvous with and landing on the target NEO during NEO close approach (<0.3 AU) to the Earth-Moon system using low-thrust/high-impulse propulsion systems. Mission durations are on the order 100 to 400 days. Mission feasibility and preliminary design analysis are presented, along with detailed trajectory calculations.
Mongolian-Russian cooperation at the Khureltogoot observatory in the ISON project framework
NASA Astrophysics Data System (ADS)
Tungalag, Namkhai; Rentsenmyagmar, Buyankhishig; Turmunkh, Bayarbat; Tsogt-Ochir, Shijirbayar; Molotov, Igor; Voropaev, Viktor; Kouprianov, Vladimir; Krugly, Yury; Schmalz, Sergey; Pozanenko, Aleksey
2014-09-01
Since autumn 2012, the Research Center of Astronomy and Geophysics, Academy of Sciences of Mongolia, in collaboration with the International Scientific Optical Network (ISON) coordinated by the Keldysh Institute for Applied Mathematics (KIAM), Russian Academy of Sciences, have conducted a large number of astronomical observations of space debris, asteroids, and the optical afterglows of gamma-ray bursts (GRBs) at the new facility of the Khureltogoot observatory near Ulaanbaatar. To the date, ISON joins 35 observation facilities with 80 telescopes of apertures from 12.5 cm to 2.6 m in 15 countries and carries out research on space debris, asteroids, and GRBs. 8.4 million measurements in 1.21 million tracklets of about 4000 Earth-orbiting objects were collected by the ISON network in 2013. It is planned that a part of the orbital data will be accessible via a UN-hosted web page in 2014. A new pavilion was built at Khureltogoot during 2012 to initiate collaboration with ISON. Since November 2012, observations began with the VT-78a 19.2 cm telescopes, with a field of view of 7×7 degrees on a robotic WS-180 mount. The telescope is controlled by the CHAOS TCS software; CCD image processing is done using the APEX II software platform developed within the ISON project. This telescope provides extended surveys of a visible part of the geostationary ring from 0 to 20 degrees inclination, with up to 15 thousand measurements of 500 to 700 objects per night. The limiting magnitude is 14 mag for 10 s exposure time, while the time span of individual tracklets is up to several hours. These surveys help KIAM to increase the accuracy of geostationary Earth-orbit (GEO) object orbits for conjunction analysis, to detect maneuvers of active satellites, and to assist in maintaining the orbits of GEO objects in clusters. Moreover, many HEO objects are detected as a by-product. Since November 2013, a new 40 cm telescope, ORI-40 with the field of view of 2.3×2.3 degrees on a robotic WS-240 mount, has been commissioned to provide dedicated observations of faint space debris fragments. The limiting magnitude is 16.5 mag for 10 s exposure time.
NASA Astrophysics Data System (ADS)
Wulamu, A.; Fishman, J.; Maimaitiyiming, M.; Leitch, J. W.; Zoogman, P.; Liu, X.; Chance, K.; Marshall, B.
2015-12-01
Understanding the bi-directional reflectance function (BRDF) and spectral albedo of various land-cover types is critical for retrieval of trace gas measurements from planned geostationary satellites such as the Tropospheric Emissions: Monitoring of Pollution (TEMPO). Radiant energy, which will be measured by these instruments at the top of atmosphere (TOA) at unprecedented spectral resolution, is strongly influenced by how this energy is reflected by the underlying surface. Thus, it is critical that we understand this phenomenon at comparable wavelength resolution. As part of the NASA ESTO-funded Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) development project, we carried out synchronous field and airborne data collection campaigns in the St Louis Metro region in Summer 2014. We collected spectral reflectance data of various land cover types on the ground within hours of a GeoTASO overpass using a field-based hyperspectral spectroradiometer (model PSR3500 from Spectral Evolution). Field measurements collecting in-situ spectral albedo and bidirectional reflectance factors were also obtained in July and August of 2015. In this study, we present our preliminary findings from in-situ and airborne GeoTASO derived spectral albedo and BRDF characteristics of major land cover types at TEMPO spectral profiles, which are necessary for the accurate retrieval of tropospheric trace gases and aerosols. First, a spectral database of various targets (e.g., plants, soils, rocks, man-made objects and water) was developed using field measurements. Next, the GeoTASO airborne data were corrected using MODTRAN and field measurements to derive spectral albedo and BRDF. High spatial resolution land-cover types were extracted using satellite images (e.g., Landsat, WorldView, IKONOS, etc.) at resolutions from 2 m - 30 m. Lastly, spectral albedo/BRDFs corresponding to various land cover types were analyzed using both field and GeoTASO measurements.
Publishing Data on Physical Samples Using the GeoLink Ontology and Linked Data Platforms
NASA Astrophysics Data System (ADS)
Ji, P.; Arko, R. A.; Lehnert, K. A.; Song, L.; Carter, M. R.; Hsu, L.
2015-12-01
Interdisciplinary Earth Data Alliance (IEDA), one of partners in EarthCube GeoLink project, seeks to explore the extent to which the use of GeoLink reusable Ontology Design Patterns (ODPs) and linked data platforms in IEDA data infrastructure can make research data more easily accessible and valuable. Linked data for the System for Earth Sample Registration (SESAR) is the first effort of IEDA to show how linked data enhance the presentation of IEDA data system architecture. SESAR Linked Data maps each table and column in SESAR database to RDF class and property based on GeoLink view, which build on the top of GeoLink ODPs. Then, uses D2RQ dumping the contents of SESAR database into RDF triples on the basis of mapping results. And, the dumped RDF triples is loaded into GRAPHDB, an RDF graph database, as permanent data in the form of atomic facts expressed as subjects, predicates and objects which provide support for semantic interoperability between IEDA and other GeoLink partners. Finally, an integrated browsing and searching interface build on Callimachus, a highly scalable platform for publishing linked data, is introduced to make sense of data stored in triplestore. Drill down and through features are built in the interface to help users locating content efficiently. The drill down feature enables users to explore beyond the summary information in the instance list of a specific class and into the detail from the specific instance page. The drill through feature enables users to jump from one instance to another one by simply clicking the link of the latter nested in the former region. Additionally, OpenLayers map is embedded into the interface to enhance the attractiveness of the presentation of instance which has geospatial information. Furthermore, by linking instances in the SESAR datasets to matching or corresponding instances in external sets, the presentation has been enriched with additional information about related classes like person, cruise, etc.
CEOS Ocean Variables Enabling Research and Applications for Geo (COVERAGE)
NASA Astrophysics Data System (ADS)
Tsontos, V. M.; Vazquez, J.; Zlotnicki, V.
2017-12-01
The CEOS Ocean Variables Enabling Research and Applications for GEO (COVERAGE) initiative seeks to facilitate joint utilization of different satellite data streams on ocean physics, better integrated with biological and in situ observations, including near real-time data streams in support of oceanographic and decision support applications for societal benefit. COVERAGE aligns with programmatic objectives of CEOS (the Committee on Earth Observation Satellites) and the missions of GEO-MBON (Marine Biodiversity Observation Network) and GEO-Blue Planet, which are to advance and exploit synergies among the many observational programs devoted to ocean and coastal waters. COVERAGE is conceived of as 3 year pilot project involving international collaboration. It focuses on implementing technologies, including cloud based solutions, to provide a data rich, web-based platform for integrated ocean data delivery and access: multi-parameter observations, easily discoverable and usable, organized by disciplines, available in near real-time, collocated to a common grid and including climatologies. These will be complemented by a set of value-added data services available via the COVERAGE portal including an advanced Web-based visualization interface, subsetting/extraction, data collocation/matchup and other relevant on demand processing capabilities. COVERAGE development will be organized around priority use cases and applications identified by GEO and agency partners. The initial phase will be to develop co-located 25km products from the four Ocean Virtual Constellations (VCs), Sea Surface Temperature, Sea Level, Ocean Color, and Sea Surface Winds. This aims to stimulate work among the ocean VCs while developing products and system functionality based on community recommendations. Such products as anomalies from a time mean, would build on the theme of applications with a relevance to CEOS/GEO mission and vision. Here we provide an overview of the COVERAGE initiative with an emphasis on international collaborative aspects entailed with the intent of soliciting community feedback as we develop and implement
Geo-Acoustic Doppler Spectroscopy: A Novel Acoustic Technique For Surveying The Seabed
NASA Astrophysics Data System (ADS)
Buckingham, Michael J.
2010-09-01
An acoustic inversion technique, known as Geo-Acoustic Doppler Spectroscopy, has recently been developed for estimating the geo-acoustic parameters of the seabed in shallow water. The technique is unusual in that it utilizes a low-flying, propeller-driven light aircraft as an acoustic source. Both the engine and propeller produce sound and, since they are rotating sources, the acoustic signature of each takes the form of a sequence of narrow-band harmonics. Although the coupling of the harmonics across the air-sea interface is inefficient, due to the large impedance mismatch between air and water, sufficient energy penetrates the sea surface to provide a useable underwater signal at sensors either in the water column or buried in the sediment. The received signals, which are significantly Doppler shifted due to the motion of the aircraft, will have experienced a number of reflections from the seabed and thus they contain information about the sediment. A geo-acoustic inversion of the Doppler-shifted modes associated with each harmonic yields an estimate of the sound speed in the sediment; and, once the sound speed has been determined, the known correlations between it and the remaining geo-acoustic parameters allow all of the latter to be computed. This inversion technique has been applied to aircraft data collected in the shallow water north of Scripps pier, returning values of the sound speed, shear speed, porosity, density and grain size that are consistent with the known properties of the sandy sediment in the channel.
NASA Astrophysics Data System (ADS)
Anaya, A. A.; Padilla, I. Y.; Macchiavelli, R. E.
2011-12-01
Karst groundwater systems are highly productive and provide an important fresh water resource for human development and ecological integrity. Their high productivity is often associated with conduit flow and high matrix permeability. The same characteristics that make these aquifers productive also make them highly vulnerable to contamination and a likely for contaminant exposure. Of particular interest are chlorinated organic contaminants and phthalates derived from industrial solvents and plastic by-products. These chemicals have been identified as potential precursors of pre-term birth, a leading cause of neonatal complications with a significant health and societal cost. The general objectives of this work are to: (1) develop fundamental knowledge and determine the processes controlling the release, mobility, persistence, and possible pathways of contaminants in karst groundwater systems, and (2) characterize transport processes in conduit and diffusion-dominated flow under base flow and storm flow conditions. The work presented herein focuses on the development of geo-hydro statistical tools to characterize flow and transport processes under different flow regimes. Multidimensional, laboratory-scale Geo-Hydrobed models were developed and tested for this purpose. The models consist of stainless-steel tanks containing karstified limestone blocks collected from the karst aquifer formation of northern Puerto Rico. The models a network of sampling wells to monitor flow, pressure, and solute concentrations temporally and spatially. Experimental work entailed making a series of point injections in wells while monitoring the hydraulic response in other wells. Statistical mixed models were applied to spatial probabilities of hydraulic response and weighted injected volume data, and were used to determinate the best spatial correlation structure to represent paths of preferential flow in the limestone units under different groundwater flow regimes. Preliminary testing of the karstified models show that the system can be used to represent the variable transport regime characterized by conduit and diffuses flow in the karst systems. Initial hydraulic characterization indicates a highly heterogeneous system resulting in large preferential flow components. Future works involve characterization of dual porosity system using conservative tracers, fate and transport experiments using phthalates and chlorinated solvents, geo-temporal statistical modeling, and the testing of "green" remediation technologies in karst groundwater. This work is supported by the U.S. Department of Energy, Savannah River (Grant Award No. DE-FG09-07SR22571), and the National Institute of Environmental Health Sciences (NIEHS, Grant Award No. P42ES017198).
Implementing marine organic aerosols into the GEOS-Chem model
Gantt, B.; Johnson, M. S.; Crippa, M.; ...
2015-03-17
Marine-sourced organic aerosols (MOAs) have been shown to play an important role in tropospheric chemistry by impacting surface mass, cloud condensation nuclei, and ice nuclei concentrations over remote marine and coastal regions. In this work, an online marine primary organic aerosol emission parameterization, designed to be used for both global and regional models, was implemented into the GEOS-Chem (Global Earth Observing System Chemistry) model. The implemented emission scheme improved the large underprediction of organic aerosol concentrations in clean marine regions (normalized mean bias decreases from -79% when using the default settings to -12% when marine organic aerosols are added). Modelmore » predictions were also in good agreement (correlation coefficient of 0.62 and normalized mean bias of -36%) with hourly surface concentrations of MOAs observed during the summertime at an inland site near Paris, France. Our study shows that MOAs have weaker coastal-to-inland concentration gradients than sea-salt aerosols, leading to several inland European cities having >10% of their surface submicron organic aerosol mass concentration with a marine source. The addition of MOA tracers to GEOS-Chem enabled us to identify the regions with large contributions of freshly emitted or aged aerosol having distinct physicochemical properties, potentially indicating optimal locations for future field studies.« less
Typical Geo-Hazards and Countermeasures of Mines in Yunnan Province, Southwest China
NASA Astrophysics Data System (ADS)
Cheng, Xianfeng; Qi, Wufu; Huang, Qianrui; Zhao, Xueqiong; Fang, Rong; Xu, Jun
2016-10-01
Mining-induced geo-hazards have caused enormous destruction and threat to mines. Known as the "kingdom of nonferrous metals" and located in Southwest China, Yunnan Province developed mining-induced geo-hazards well with characteristics of multiple types, widespread distribution and serious damage. Landslides and debris flows are two common sub-types of geohazards causing most serious damage in Yunnan, and some of them were very representative in the world. Two landslides and two debris flows were chosen to analyze deeply. Both Laojinshan Landslide and Sunjiaqing Landslide possess the characteristic of rock avalanches. The high sliding speed and long distance made the landslides translate into clastic flows with impact force and caused enormous destruction. Rainstorm and mining waste rock were two main factors to induce debris flows in Yunnan mines. Heishan valley debris flow of Dongchuan copper mine was a super large rainstorm type viscose debris flow with very low frequency, which brought a good caution to utilize valleys which looked an unlikely debris flow. Nandagou Valley of Jinding lead-zinc mine in Lanping County was a rainstorm stimulating, gully-type, high frequency and large scale debris flow, which was induced by mining activities. Many countermeasures have been used for Yunnan mines, including engineering treatment technology and ecological remediation, monitoring and forecasting, relocation and public administration.
Local and global evaluation for remote sensing image segmentation
NASA Astrophysics Data System (ADS)
Su, Tengfei; Zhang, Shengwei
2017-08-01
In object-based image analysis, how to produce accurate segmentation is usually a very important issue that needs to be solved before image classification or target recognition. The study for segmentation evaluation method is key to solving this issue. Almost all of the existent evaluation strategies only focus on the global performance assessment. However, these methods are ineffective for the situation that two segmentation results with very similar overall performance have very different local error distributions. To overcome this problem, this paper presents an approach that can both locally and globally quantify segmentation incorrectness. In doing so, region-overlapping metrics are utilized to quantify each reference geo-object's over and under-segmentation error. These quantified error values are used to produce segmentation error maps which have effective illustrative power to delineate local segmentation error patterns. The error values for all of the reference geo-objects are aggregated through using area-weighted summation, so that global indicators can be derived. An experiment using two scenes of very different high resolution images showed that the global evaluation part of the proposed approach was almost as effective as other two global evaluation methods, and the local part was a useful complement to comparing different segmentation results.
United Kingdom Infrared Telescope's Spectrograph Observations of Human-Made Space Objects
NASA Technical Reports Server (NTRS)
Buckalew, Brent; Abercromby, Kira; Lederer, Susan; Frith, James; Cowardin, Heather
2017-01-01
Presented here are the results of the United Kingdom Infrared Telescope (UKIRT) spectral observations of human-made space objects taken from 2014 to 2015. The data collected using the UIST infrared spectrograph cover the wavelength range 0.7-2.5 micrometers. Overall, data were collected on 18 different orbiting objects at or near the geosynchronous (GEO) regime. Thirteen of the objects are spacecraft, one is a rocket body, and four are cataloged as debris pieces. The remotely collected data are compared to the laboratory-collected reflectance data on typical spacecraft materials; thereby general materials are identified but not specific types. These results highlight the usefulness of observations in the infrared by focusing on features from hydrocarbons and silicon. The spacecraft show distinct features due to the presence of solar panels. Signature variations between rocket bodies, due to the presence of various metals and paints on their surfaces, show a clear distinction from those objects with solar panels, demonstrating that one can distinguish most spacecraft from rocket bodies through infrared spectrum analysis. Finally, the debris pieces tend to show featureless, dark spectra. These results show that the laboratory data in its current state give excellent indications as to the nature of the surface materials on the objects. Further telescopic data collection and model updates to include more materials, noise, surface roughness, and material degradation are necessary to make better assessments of orbital object material types. A comparison conducted between objects observed previously with the NASA Infrared Telescope Facility (IRTF) shows similar materials and trends from the two telescopes and from the two distinct data sets. However, based on the current state of the model, infrared spectroscopic data are adequate to classify objects in GEO as spacecraft, rocket bodies, or debris.
The New NASA Orbital Debris Engineering Model ORDEM 3.0
NASA Technical Reports Server (NTRS)
Krisko, P. H.
2014-01-01
The NASA Orbital Debris Program Office (ODPO) has released its latest Orbital Debris Engineering Model, ORDEM 3.0. It supersedes ORDEM 2000, now referred to as ORDEM 2.0. This newer model encompasses the Earth satellite and debris flux environment from altitudes of low Earth orbit (LEO) through geosynchronous orbit (GEO). Debris sizes of 10 micron through larger than 1 m in non-GEO and 10 cm through larger than 1 m in GEO are available. The inclusive years are 2010 through 2035. The ORDEM model series has always been data driven. ORDEM 3.0 has the benefit of many more hours of data from existing sources and from new sources than past ORDEM versions. The object data range in size from 10 µm to larger than 1 m, and include in situ and remote measurements. The in situ data reveals material characteristics of small particles. Mass densities are grouped in ORDEM 3.0 in terms of 'high-density', represented by 7.9 g/cc, 'medium-density' represented by 2.8 g/cc and 'low-density' represented by 1.4 g/cc. Supporting models have also advanced significantly. The LEO-to-GEO ENvironment Debris model (LEGEND) includes an historical and a future projection component with yearly populations that include launched and maneuvered intact spacecraft and rocket bodies, mission related debris, and explosion and collision event fragments. LEGEND propagates objects with ephemerides and physical characteristics down to 1 mm in size. The full LEGEND yearly population acts as an a priori condition for a Bayesian statistical model. Specific populations are added from sodium potassium droplet releases, recent major accidental and deliberate collisions, and known anomalous debris events. This paper elaborates on the upgrades of this model over previous versions. Sample validation results with remote and in situ measurements are shown, and the consequences of including material density are discussed as it relates to heightened risks to crewed and robotic spacecraft
GEO-CAPE Coastal Ocean Ecosystem Dynamics White Paper: EPA Section
The Clean Water Act protects all navigable waters in the United States (CWA, 1988). The objective of the CWA is to "restore and maintain the chemical, physical, and biological integrity of the Nation's waters." This Federal mandate authorizes states, tribes, and U.S. te...
Momentum and Energy Assessments with NASA and Other Model and Data Assimilation Systems
NASA Technical Reports Server (NTRS)
Salstein, David; Nelson, Peter; Hu, Wen-Jie
2001-01-01
Support from the NASA Global Modeling and Analysis Program has been used for the following research objectives: 1) the study of aspects of dynamics of torques and angular momentum based on the Goddard GEOS and other analyses; 2) the study of how models participating in the second Atmospheric Model Intercomparison Project (AMIP-2) have success in simulating certain large-scale quantities; 3) the study of the energetics and momentum cycle from certain runs from the Goddard Laboratory for Atmospheres and other models as well; 4) the assessment of changes in diabatic heating and related energetics in the community climate model (CCM3); 5) the analysis of modes of climate of the atmosphere, especially the Arctic and North Atlantic Oscillations. Further information on these endeavors will be provided in published works and the Final Report of the project.
NASA Astrophysics Data System (ADS)
Direito, Maria Susana; Staats, Martijn; Foing, Bernard H.; Ehrenfreund, Pascale; Roling, Wilfred
The Utah Mars Desert Research Station (MDRS) harbours geo-morphology and geo-processes analogues to the planet Mars. Soil samples were collected during the EuroGeoMars campaign (from 24 January to 1 March 2009) from different locations and depths [1]. Samples were distributed among scientific collaborator institutes for analysis of microbial diversity, amino acid content and degradation, content of PAH or larger organic molecules, and respective soil properties. Our sample analysis had the objective of characterizing the microbial communities in this Mars analogue: DNA isolation, PCR (Polymerase Chain Reaction) using primers for DNA amplification of Bacteria, Archaea and Eukarya ribosomal RNA (rRNA) gene fragments, DGGE (Denaturing Gradient Gel Electrophoresis) and clone library construction with the final aim of sequencing. Results indicate that life is present in all the three domains of life (Archaea, Bacteria and Eukarya), while the most diversity was found in the domain Bacteria. Microorgan-isms are heterogeneously present and their identities are currently investigated. The obtained information will be later related to the other scientific analysis in order to obtain a better understanding of this Mars analogue site, which in turn will provide important information for the search for life on Mars. [1] Foing, B.H. et al . (2009). Exogeolab lander/rover instruments and EuroGeoMars MDRS campaign. LPI, 40, 2567.
Spotting East African mammals in open savannah from space.
Yang, Zheng; Wang, Tiejun; Skidmore, Andrew K; de Leeuw, Jan; Said, Mohammed Y; Freer, Jim
2014-01-01
Knowledge of population dynamics is essential for managing and conserving wildlife. Traditional methods of counting wild animals such as aerial survey or ground counts not only disturb animals, but also can be labour intensive and costly. New, commercially available very high-resolution satellite images offer great potential for accurate estimates of animal abundance over large open areas. However, little research has been conducted in the area of satellite-aided wildlife census, although computer processing speeds and image analysis algorithms have vastly improved. This paper explores the possibility of detecting large animals in the open savannah of Maasai Mara National Reserve, Kenya from very high-resolution GeoEye-1 satellite images. A hybrid image classification method was employed for this specific purpose by incorporating the advantages of both pixel-based and object-based image classification approaches. This was performed in two steps: firstly, a pixel-based image classification method, i.e., artificial neural network was applied to classify potential targets with similar spectral reflectance at pixel level; and then an object-based image classification method was used to further differentiate animal targets from the surrounding landscapes through the applications of expert knowledge. As a result, the large animals in two pilot study areas were successfully detected with an average count error of 8.2%, omission error of 6.6% and commission error of 13.7%. The results of the study show for the first time that it is feasible to perform automated detection and counting of large wild animals in open savannahs from space, and therefore provide a complementary and alternative approach to the conventional wildlife survey techniques.
Bordetella pertussis infections in travelers: data from the GeoSentinel global network.
Barbosa, Felipe; Barnett, Elizabeth D; Gautret, Philippe; Schlagenhauf, Patricia; van Genderen, Perry J J; Grobusch, Martin P; Connor, Bradley A; Hamer, Davidson H; Hochberg, Natasha S
2017-05-01
Pertussis is a highly contagious, vaccine-preventable respiratory infection that is endemic worldwide. There are limited data regarding the occurrence of pertussis in travelers. The objective of this study is to identify travel-related pertussis cases reported to the GeoSentinel Surveillance Network. This is a descriptive, retrospective analysis of GeoSentinel records from 25 travel/tropical medicine clinics in 16 countries. Frequencies of demographic and travel-related characteristics and symptoms of 74 cases of pertussis in travelers and new immigrants from 1999 to 2015 were analysed. There were 74 probable and confirmed cases of pertussis in the GeoSentinel database; median age was 44 years, and 38 (51%) patients were female. Tourism was the most common reason for travel (41; 55%). Country of exposure was determined in 66 cases with travelers returning from India and China constituting the highest number of cases (10 cases each; 15% each). Seventy of 74 (95%) patients had respiratory symptoms, while fatigue and fever were reported by 21 (28%) and 20 (27%), respectively. Immunization status against pertussis was unknown. Most cases were reported after 2005 (69; 93%). Our study describes 74 cases of pertussis acquired during travel and reported to the GeoSentinel Network. Pertussis should be considered in returned travelers who present with respiratory symptoms. Surveillance and detection of imported cases are important to prevent onward transmission in the community. The pre-travel consultation provides an opportunity to verify immunization status and provide routine vaccinations such as pertussis. © International Society of Travel Medicine, 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com
On geoid heights derived from GEOS 3 altimeter data along the Hawaiian-Emperor seamount chain
NASA Technical Reports Server (NTRS)
Watts, A. B.
1979-01-01
The geoid heights derived from preliminary GEOS 3 satellite radar altimeter data over the Hawaiian-Emperor seamount chain are examined. Two objectives are pursued: (1) to evaluate the contribution of the topography of the seamount chain and its compensation to the marine geoid; and (2) to determine whether geoid heights derived from GEOS 3 altimeter data can be used to provide information on isostasy at geological features such as the Hawaiian-Emperor seamount chain which formed as relatively young loads on the oceanic lithosphere. Short-wavelength geoid highs of 5-12 m over the crest of the seamount chain and geoid lows over flanking regions are observed. The geological undulations can be explained by a simple model in which the seamount-chain load is supported by a strong rigid lithospheric plate. The elastic thickness estimates agree with values based on surface ship gravity and bathymetry observations, and provide further support to the hypothesis that the elastic thickness acquired at a surface load depends on the temperature gradient of the lithosphere at the time of loading.
File Specification for GEOS-5 FP (Forward Processing)
NASA Technical Reports Server (NTRS)
Lucchesi, R.
2013-01-01
The GEOS-5 FP Atmospheric Data Assimilation System (GEOS-5 ADAS) uses an analysis developed jointly with NOAA's National Centers for Environmental Prediction (NCEP), which allows the Global Modeling and Assimilation Office (GMAO) to take advantage of the developments at NCEP and the Joint Center for Satellite Data Assimilation (JCSDA). The GEOS-5 AGCM uses the finite-volume dynamics (Lin, 2004) integrated with various physics packages (e.g, Bacmeister et al., 2006), under the Earth System Modeling Framework (ESMF) including the Catchment Land Surface Model (CLSM) (e.g., Koster et al., 2000). The GSI analysis is a three-dimensional variational (3DVar) analysis applied in grid-point space to facilitate the implementation of anisotropic, inhomogeneous covariances (e.g., Wu et al., 2002; Derber et al., 2003). The GSI implementation for GEOS-5 FP incorporates a set of recursive filters that produce approximately Gaussian smoothing kernels and isotropic correlation functions. The GEOS-5 ADAS is documented in Rienecker et al. (2008). More recent updates to the model are presented in Molod et al. (2011). The GEOS-5 system actively assimilates roughly 2 × 10(exp 6) observations for each analysis, including about 7.5 × 10(exp 5) AIRS radiance data. The input stream is roughly twice this volume, but because of the large volume, the data are thinned commensurate with the analysis grid to reduce the computational burden. Data are also rejected from the analysis through quality control procedures designed to detect, for example, the presence of cloud. To minimize the spurious periodic perturbations of the analysis, GEOS-5 FP uses the Incremental Analysis Update (IAU) technique developed by Bloom et al. (1996). More details of this procedure are given in Appendix A. The assimilation is performed at a horizontal resolution of 0.3125-degree longitude by 0.25- degree latitude and at 72 levels, extending to 0.01 hPa. All products are generated at the native resolution of the horizontal grid. The majority of data products are time-averaged, but four instantaneous products are also available. Hourly data intervals are used for two-dimensional products, while 3-hourly intervals are used for three-dimensional products. These may be on the model's native 72-layer vertical grid or at 42 pressure surfaces extending to 0.1 hPa. This document describes the gridded output files produced by the GMAO near real-time operational FP, using the most recent version of the GEOS-5 assimilation system. Additional details about variables listed in this file specification can be found in a separate document, the GEOS-5 File Specification Variable Definition Glossary. Documentation about the current access methods for products described in this document can be found on the GMAO products page: http://gmao.gsfc.nasa.gov/products/.
File Specification for GEOS-5 FP-IT (Forward Processing for Instrument Teams)
NASA Technical Reports Server (NTRS)
Lucchesi, R.
2013-01-01
The GEOS-5 FP-IT Atmospheric Data Assimilation System (GEOS-5 ADAS) uses an analysis developed jointly with NOAA's National Centers for Environmental Prediction (NCEP), which allows the Global Modeling and Assimilation Office (GMAO) to take advantage of the developments at NCEP and the Joint Center for Satellite Data Assimilation (JCSDA). The GEOS-5 AGCM uses the finite-volume dynamics (Lin, 2004) integrated with various physics packages (e.g, Bacmeister et al., 2006), under the Earth System Modeling Framework (ESMF) including the Catchment Land Surface Model (CLSM) (e.g., Koster et al., 2000). The GSI analysis is a three-dimensional variational (3DVar) analysis applied in grid-point space to facilitate the implementation of anisotropic, inhomogeneous covariances (e.g., Wu et al., 2002; Derber et al., 2003). The GSI implementation for GEOS-5 FP-IT incorporates a set of recursive filters that produce approximately Gaussian smoothing kernels and isotropic correlation functions. The GEOS-5 ADAS is documented in Rienecker et al. (2008). More recent updates to the model are presented in Molod et al. (2011). The GEOS-5 system actively assimilates roughly 2 × 10(exp 6) observations for each analysis, including about 7.5 × 10(exp 5) AIRS radiance data. The input stream is roughly twice this volume, but because of the large volume, the data are thinned commensurate with the analysis grid to reduce the computational burden. Data are also rejected from the analysis through quality control procedures designed to detect, for example, the presence of cloud. To minimize the spurious periodic perturbations of the analysis, GEOS-5 FP-IT uses the Incremental Analysis Update (IAU) technique developed by Bloom et al. (1996). More details of this procedure are given in Appendix A. The analysis is performed at a horizontal resolution of 0.625-degree longitude by 0.5-degree latitude and at 72 levels, extending to 0.01 hPa. All products are generated at the native resolution of the horizontal grid. The majority of data products are time-averaged, but four instantaneous products are also available. Hourly data intervals are used for two-dimensional products, while 3-hourly intervals are used for three-dimensional products. These may be on the model's native 72-layer vertical grid or at 42 pressure surfaces extending to 0.1 hPa. This document describes the gridded output files produced by the GMAO near real-time operational GEOS-5 FP-IT processing in support of the EOS instrument teams. Additional details about variables listed in this file specification can be found in a separate document, the GEOS-5 File Specification Variable Definition Glossary.
GeoSciML version 3: A GML application for geologic information
NASA Astrophysics Data System (ADS)
International Union of Geological Sciences., I. C.; Richard, S. M.
2011-12-01
After 2 years of testing and development, XML schema for GeoSciML version 3 are now ready for application deployment. GeoSciML draws from many geoscience data modelling efforts to establish a common suite of feature types to represent information associated with geologic maps (materials, structures, and geologic units) and observations including structure data, samples, and chemical analyses. After extensive testing and use case analysis, in December 2008 the CGI Interoperability Working Group (IWG) released GeoSciML 2.0 as an application schema for basic geological information. GeoSciML 2.0 is in use to deliver geologic data by the OneGeology Europe portal, the Geological Survey of Canada Groundwater Information Network (wet GIN), and the Auscope Mineral Resources portal. GeoSciML to version 3.0 is updated to OGC Geography Markup Language v3.2, re-engineered patterns for association of element values with controlled vocabulary concepts, incorporation of ISO19156 Observation and Measurement constructs for representing numeric and categorical values and for representing analytical data, incorporation of EarthResourceML to represent mineral occurrences and mines, incorporation of the GeoTime model to represent GSSP and stratigraphic time scale, and refactoring of the GeoSciML namespace to follow emerging ISO practices for decoupling of dependencies between standardized namespaces. These changes will make it easier for data providers to link to standard vocabulary and registry services. The depth and breadth of GeoSciML remains largely unchanged, covering the representation of geologic units, earth materials and geologic structures. ISO19156 elements and patterns are used to represent sampling features such as boreholes and rock samples, as well as geochemical and geochronologic measurements. Geologic structures include shear displacement structures (brittle faults and ductile shears), contacts, folds, foliations, lineations and structures with no preferred orientation (e.g. 'miarolitic cavities'). The Earth material package allows for the description of both individual components, such as minerals, and compound materials, such as rocks or unconsolidated materials. Provision is made for alteration, weathering, metamorphism, particle geometry, fabric, and petrophysical descriptions. Mapped features describe the shape of the geological features using standard GML geometries, such as polygons, lines, points or 3D volumes. Geological events provide the age, process and environment of formation of geological features. The Earth Resource section includes features to represent mineral occurrences and mines and associated human activities independently. This addition allows description of resources and reserves that can comply with national and internationally accepted reporting codes. GeoSciML v3 is under consideration as the data model for INSPIRE annex 2 geologic reporting in Europe.
NASA Technical Reports Server (NTRS)
Miller, L. S.
1977-01-01
A number of GEOS-3 passes over the Atlantic Ocean and Southeastern U.S. are examined. Surface-truth and radar altimeter data comparisons are given in terms of surface correlation length, signal fluctuation characteristics, and altitude tracker dynamic response. Detailed analyses are given regarding spatial resolution and its dependency on angular backscatter behavior. These analyses include data from passes over ocean (diffuse scatter), land (large body scatter), and mirror-like inland water areas (pseudo-specular scatter). Altimeter data are examined for a pass over a large reservoir and marsh area of differing water levels; this geometry represents a stepchange in altitude which is usable in determination of the transient response of the tracker. The extent to which pulse-length limited operation pertains over-land is examined. A Wiener filter altitude algorithm is discussed which permits specification of tracker variance and geoidal spectral characteristics during operation.
4-D drive-through visualization of I-280 for review of proposed signing.
DOT National Transportation Integrated Search
1998-10-01
The primary objective of this work was to produce a simulated 4D drive-through of a portion of highway(I-280 through : Newark, NJ) for which proposed traffic-generator signing had to be reviewed. A 4D visualization was produced that combined 3D : geo...
Assessment of in situ test technology for construction control of base courses and embankments.
DOT National Transportation Integrated Search
2008-04-01
The main objective of this research is to assess the use of three nondestructive testing devices, the GeoGauge, the LFWD, and the DCP, in order to evaluate the in situ elastic modulus of highway materials for application in the quality assurance/qual...
Infrared Telescope Facility's Spectrograph Observations of Human-Made Space Objects
NASA Technical Reports Server (NTRS)
Abercromby, K.; Buckalew, B.; Abell, P.; Cowardin, H.
2015-01-01
Presented here are the results of the Infrared Telescope Facility (IRTF) spectral observations of human-made space objects taken from 2006 to 2008. The data collected using the SpeX infrared spectrograph cover the wavelength range 0.7-2.5 micrometers. Overall, data were collected on 20 different orbiting objects at or near the geosynchronous (GEO) regime. Four of the objects were controlled spacecraft, seven were non-controlled spacecraft, five were rocket bodies, and the final four were cataloged as debris pieces. The remotely collected data are compared to the laboratory-collected reflectance data on typical spacecraft materials, thereby general materials are identified but not specific types. These results highlight the usefulness of observations in the infrared by focusing on features from hydrocarbons, silicon, and thermal emission. The spacecraft, both the controlled and non-controlled, show distinct features due to the presence of solar panels, whereas the rocket bodies do not. Signature variations between rocket bodies, due to the presence of various metals and paints on their surfaces, show a clear distinction from those objects with solar panels, demonstrating that one can distinguish most spacecraft from rocket bodies through infrared spectrum analysis. Finally, the debris pieces tend to show featureless, dark spectra. These results show that the laboratory data in its current state give excellent indications as to the nature of the surface materials on the objects. Further telescopic data collection and model updates to include noise, surface roughness, and material degradation are necessary to make better assessments of orbital object material types. However, based on the current state of the comparison between the observations and the laboratory data, infrared spectroscopic data are adequate to classify objects in GEO as spacecraft, rocket bodies, or debris.
Assembler: Efficient Discovery of Spatial Co-evolving Patterns in Massive Geo-sensory Data.
Zhang, Chao; Zheng, Yu; Ma, Xiuli; Han, Jiawei
2015-08-01
Recent years have witnessed the wide proliferation of geo-sensory applications wherein a bundle of sensors are deployed at different locations to cooperatively monitor the target condition. Given massive geo-sensory data, we study the problem of mining spatial co-evolving patterns (SCPs), i.e ., groups of sensors that are spatially correlated and co-evolve frequently in their readings. SCP mining is of great importance to various real-world applications, yet it is challenging because (1) the truly interesting evolutions are often flooded by numerous trivial fluctuations in the geo-sensory time series; and (2) the pattern search space is extremely large due to the spatiotemporal combinatorial nature of SCP. In this paper, we propose a two-stage method called Assembler. In the first stage, Assembler filters trivial fluctuations using wavelet transform and detects frequent evolutions for individual sensors via a segment-and-group approach. In the second stage, Assembler generates SCPs by assembling the frequent evolutions of individual sensors. Leveraging the spatial constraint, it conceptually organizes all the SCPs into a novel structure called the SCP search tree, which facilitates the effective pruning of the search space to generate SCPs efficiently. Our experiments on both real and synthetic data sets show that Assembler is effective, efficient, and scalable.
Geographical Topics Learning of Geo-Tagged Social Images.
Zhang, Xiaoming; Ji, Shufan; Wang, Senzhang; Li, Zhoujun; Lv, Xueqiang
2016-03-01
With the availability of cheap location sensors, geotagging of images in online social media is very popular. With a large amount of geo-tagged social images, it is interesting to study how these images are shared across geographical regions and how the geographical language characteristics and vision patterns are distributed across different regions. Unlike textual document, geo-tagged social image contains multiple types of content, i.e., textual description, visual content, and geographical information. Existing approaches usually mine geographical characteristics using a subset of multiple types of image contents or combining those contents linearly, which ignore correlations between different types of contents, and their geographical distributions. Therefore, in this paper, we propose a novel method to discover geographical characteristics of geo-tagged social images using a geographical topic model called geographical topic model of social images (GTMSIs). GTMSI integrates multiple types of social image contents as well as the geographical distributions, in which image topics are modeled based on both vocabulary and visual features. In GTMSI, each region of the image would have its own topic distribution, and hence have its own language model and vision pattern. Experimental results show that our GTMSI could identify interesting topics and vision patterns, as well as provide location prediction and image tagging.
Develop Direct Geo-referencing System Based on Open Source Software and Hardware Platform
NASA Astrophysics Data System (ADS)
Liu, H. S.; Liao, H. M.
2015-08-01
Direct geo-referencing system uses the technology of remote sensing to quickly grasp images, GPS tracks, and camera position. These data allows the construction of large volumes of images with geographic coordinates. So that users can be measured directly on the images. In order to properly calculate positioning, all the sensor signals must be synchronized. Traditional aerial photography use Position and Orientation System (POS) to integrate image, coordinates and camera position. However, it is very expensive. And users could not use the result immediately because the position information does not embed into image. To considerations of economy and efficiency, this study aims to develop a direct geo-referencing system based on open source software and hardware platform. After using Arduino microcontroller board to integrate the signals, we then can calculate positioning with open source software OpenCV. In the end, we use open source panorama browser, panini, and integrate all these to open source GIS software, Quantum GIS. A wholesome collection of data - a data processing system could be constructed.
The Influence of Internal Model Variability in GEOS-5 on Interhemispheric CO2 Exchange
NASA Technical Reports Server (NTRS)
Allen, Melissa; Erickson, David; Kendall, Wesley; Fu, Joshua; Ott, Leslie; Pawson, Steven
2012-01-01
An ensemble of eight atmospheric CO2 simulations was completed employing the National Aeronautics and Space Administration (NASA) Goddard Earth Observation System, Version 5 (GEOS-5) for the years 2000-2001, each with initial meteorological conditions corresponding to different days in January 2000 to examine internal model variability. Globally, the model runs show similar concentrations of CO2 for the two years, but in regions of high CO2 concentrations due to fossil fuel emissions, large differences among different model simulations appear. The phasing and amplitude of the CO2 cycle at Northern Hemisphere locations in all of the ensemble members is similar to that of surface observations. In several southern hemisphere locations, however, some of the GEOS-5 model CO2 cycles are out of phase by as much as four months, and large variations occur between the ensemble members. This result indicates that there is large sensitivity to transport in these regions. The differences vary by latitude-the most extreme differences in the Tropics and the least at the South Pole. Examples of these differences among the ensemble members with regard to CO2 uptake and respiration of the terrestrial biosphere and CO2 emissions due to fossil fuel emissions are shown at Cape Grim, Tasmania. Integration-based flow analysis of the atmospheric circulation in the model runs shows widely varying paths of flow into the Tasmania region among the models including sources from North America, South America, South Africa, South Asia and Indonesia. These results suggest that interhemispheric transport can be strongly influenced by internal model variability.
2011-09-01
Crawford, K., " Time - Resolved Infrared Spectrophotometric Observations of IRIDIUM satellites and related Resident Space Objects", IAC-09-A6.1.17...Figure 10 for a geosynchronous (GEO) satellite . The figure shows three sets of multi-spectral signatures were collected at different times of the...provides a simple method to determine suitable observation conditions for the cluster of satellites . For instance, on Day 0, the times of the
Lei, Hong; Wei, Qiaonian; Wang, Qing; Su, Anxiang; Xue, Mei; Liu, Qin; Hu, Qiuhui
2017-04-01
To explore a novel kind of anti-bacterial composite material having the excellent antibacterial ability, stability and specific-targeting capability, palygorskite (PGS) was used as the carrier of ginger essential oil (GEO) and a novel kind of composite GEO-PGS was prepared by ion exchange process. The characterization and the antibacterial activity of GEO-PGS was investigated in this study. Results of FTIR, XPS, XRD,TG analysis and SEM observation demonstrated the combination of GEO and PGS, GEO was absorbed on the surface of PGS, and the content of GEO in the composite was estimated to be 18.66%. Results of minimal inhibitory concentration (MIC) analysis, growth curve and Gram staining analysis of Staphylococci aureus and Escherichia coli exposed to GEO-PGS showed that GEO-PGS had much higher antibacterial activity than GEO, and GEO-PGS had the specific-targeting antibacterial capability. Moreover, GEO-PGS showed the characteristics of thermo-stability, acidity and alkalinity-resistance in exerting its anti-bacteria activity. In conclusion, the novel composite GEO-PGS combined the bacteria-absorbent activity of PGS and the antibacterial activity of GEO, suggesting the great potential application of GEO-PGS as the novel composite substance with high antibacterial activity. Copyright © 2016 Elsevier B.V. All rights reserved.
NASA Technical Reports Server (NTRS)
Suarez, Max J. (Editor); Schubert, Siegfried; Rood, Richard; Park, Chung-Kyu; Wu, Chung-Yu; Kondratyeva, Yelena; Molod, Andrea; Takacs, Lawrence; Seablom, Michael; Higgins, Wayne
1995-01-01
The Data Assimilation Office (DAO) at Goddard Space Flight Center has produced a multiyear global assimilated data set with version 1 of the Goddard Earth Observing System Data Assimilation System (GEOS-1 DAS). One of the main goals of this project, in addition to benchmarking the GEOS-1 system, was to produce a research quality data set suitable for the study of short-term climate variability. The output, which is global and gridded, includes all prognostic fields and a large number of diagnostic quantities such as precipitation, latent heating, and surface fluxes. Output is provided four times daily with selected quantities available eight times per day. Information about the observations input to the GEOS-1 DAS is provided in terms of maps of spatial coverage, bar graphs of data counts, and tables of all time periods with significant data gaps. The purpose of this document is to serve as a users' guide to NASA's first multiyear assimilated data set and to provide an early look at the quality of the output. Documentation is provided on all the data archives, including sample read programs and methods of data access. Extensive comparisons are made with the corresponding operational European Center for Medium-Range Weather Forecasts analyses, as well as various in situ and satellite observations. This document is also intended to alert users of the data about potential limitations of assimilated data, in general, and the GEOS-1 data, in particular. Results are presented for the period March 1985-February 1990.
An optical survey for space debris on highly eccentric and inclined MEO orbits
NASA Astrophysics Data System (ADS)
Schildknecht, Thomas; Flohrer, Tim; Hinze, Andreas; Vananti, Alessandro; Silha, Jiri
Optical surveys for space debris in high-altitude orbits have been conducted since more than fifteen years. Originally these efforts concentrated mainly on the geostationary ring (GEO) and its close region. Corresponding observation strategies, processing techniques and cataloguing approaches have been developed and successfully applied. The ESA GEO surveys, e.g., resulted in the detection of a significant population of small-size debris and later in the discovery of high area-to-mass ratio objects in GEO-like orbits. The observation scenarios were successively adapted to survey the geostationary transfer orbit (GTO) region; and surveys to search for debris in the medium Earth orbit (MEO) region of the global navigation satellite constellations were successfully conducted. Comparably less experience (both, in terms of practical observation and strategy definition) is available for eccentric orbits that (at least partly) are in the MEO region, in particular for the Molniya-type orbits. Several breakup events and deliberate fragmentations are known to have taken place in such orbits. Survey and follow-up strategies for searching space debris objects in highly-eccentric MEO orbits, and to acquire orbits which are sufficiently accurate to catalogue such objects and to maintain their orbits over longer time spans were developed and, eventually, optical observations were conducted in the framework of an ESA study using ESA' Space Debris Telescope (ESASDT) the 1-m Zeiss telescope located at the Optical Ground Station (OGS) at the Teide Observatory at Tenerife, Spain. Thirteen nights of surveys of Molniya-type orbits was performed between January and August 2013. A basic survey consisted of observing a single geocentric field for 10 minutes. If a faint object was found, follow-up observations were performed during the same night to ensure a save rediscovery of the object during the next nights. Additional follow-up observations to maintain the orbits of these newly discovered faint objects were also acquired with AIUB's 1 m ZIMLAT telescope in Zimmerwald, Switzerland. Eventually, 255 basic surveys were performed during these thirteen nights corresponding to about 47 hours of observations. In total 30 uncorrelated faint objects were discovered. On average one uncorrelated object was found every 100 minutes. Some of these objects show a considerable brightness variation and have a high area-to-mass ratio as determined in the orbit estimation process. We also investigated the detection efficiency of our surveys by comparing the observation results with the TLE population by means of ESA's PROOF tool. Furthermore a comparison of the real detections with the statistical population of the ESA MASTER-2009 model was performed. The result shows that the fragment population of objects in Molniya-type orbits is underestimated in the MASTER model.
Landspotting: Social gaming to collect vast amounts of data for satellite validation
NASA Astrophysics Data System (ADS)
Fritz, S.; Purgathofer, P.; Kayali, F.; Fellner, M.; Wimmer, M.; Sturn, T.; Triebnig, G.; Krause, S.; Schindler, F.; Kollegger, M.; Perger, C.; Dürauer, M.; Haberl, W.; See, L.; McCallum, I.
2012-04-01
At present there is no single satellite-derived global land cover product that is accurate enough to provide reliable estimates of forest or cropland area to determine, e.g., how much additional land is available to grow biofuels or to tackle problems of food security. The Landspotting Project aims to improve the quality of this land cover information by vastly increasing the amount of in-situ validation data available for calibration and validation of satellite-derived land cover. The Geo-Wiki (Geo-Wiki.org) system currently allows users to compare three satellite derived land cover products and validate them using Google Earth. However, there is presently no incentive for anyone to provide this data so the amount of validation through Geo-Wiki has been limited. However, recent competitions have proven that incentive driven campaigns can rapidly create large amounts of input. The LandSpotting Project is taking a truly innovative approach through the development of the Landspotting game. The game engages users whilst simultaneously collecting a large amount of in-situ land cover information. The development of the game is informed by the current raft of successful social gaming that is available on the internet and as mobile applications, many of which are geo-spatial in nature. Games that are integrated within a social networking site such as Facebook illustrate the power to reach and continually engage a large number of individuals. The number of active Facebook users is estimated to be greater than 400 million, where 100 million are accessing Facebook from mobile devices. The Landspotting Game has similar game mechanics as the famous strategy game "Civilization" (i.e. build, harvest, research, war, diplomacy, etc.). When a player wishes to make a settlement, they must first classify the land cover over the area they wish to settle. As the game is played on the earth surface with Google Maps, we are able to record and store this land cover/land use classification geographically. Every player can play the game for free (i.e. a massive multiplayer online game). Furthermore, it is a social game on Facebook (e.g. invite friends, send friends messages, purchase gifts, help friends, post messages onto the wall, etc). The game is played in a web browser, therefore it runs everywhere (where Flash is supported) without requiring the user to install anything additional. At the same time, the Geo-Wiki system will be modified to use the acquired in-situ validation information to create new outputs: a hybrid land cover map, which takes the best information from each individual product to create a single integrated version; a database of validation points that will be freely available to the land cover user community; and a facility that allows users to create a specific targeted validation area, which will then be provided to the crowdsourcing community for validation. These outputs will turn Geo-Wiki into a valuable system for earth system scientists.
Geolab 2010: Desert Rats Field Demonstration
NASA Technical Reports Server (NTRS)
Evans, Cindy A.; Calaway, M. J.; Bell, M. S.
2009-01-01
In 2010, Desert Research and Technology Studies (Desert RATS), NASA's annual field exercise designed to test spacesuit and rover technologies, will include a first generation lunar habitat facility, the Habitat Demonstration Unit (HDU). The habitat will participate in joint operations in northern Arizona with the Lunar Electric Rover (LER) and will be used as a multi-use laboratory and working space. A Geology Laboratory or GeoLab is included in the HDU design. Historically, science participation in Desert RATS exercises has supported the technology demonstrations with geological traverse activities that are consistent with preliminary concepts for lunar surface science Extravehicular Activities (EVAs). Next year s HDU demonstration is a starting point to guide the development of requirements for the Lunar Surface Systems Program and test initial operational concepts for an early lunar excursion habitat that would follow geological traverses along with the LER. For the GeoLab, these objectives are specifically applied to support future geological surface science activities. The goal of our GeoLab is to enhance geological science returns with the infrastructure that supports preliminary examination, early analytical characterization of key samples, and high-grading lunar samples for return to Earth [1, 2] . Figure 1: Inside view schematic of the GeoLab a 1/8 section of the HDU, including a glovebox for handling and examining geological samples. Other outfitting facilities are not depicted in this figure. GeoLab Description: The centerpiece of the GeoLab is a glovebox, allowing for samples to be brought into the habitat in a protected environment for preliminary examination (see Fig. 1). The glovebox will be attached to the habitat bulkhead and contain three sample pass-through antechambers that would allow direct transfer of samples from outside the HDU to inside the glovebox. We will evaluate the need for redundant chambers, and other uses for the glovebox antechambers, such as a staging area for additional tools or samples. The sides of the glovebox are designed with instrument ports and additional smaller ports for cable pass-through, imagery feeds and environmental monitoring. This first glovebox version will be equipped with basic tools for manipulating, viewing, and early analysis of samples. The GeoLab was also designed for testing additional analytical instruments in a field setting.
Video-based Mobile Mapping System Using Smartphones
NASA Astrophysics Data System (ADS)
Al-Hamad, A.; Moussa, A.; El-Sheimy, N.
2014-11-01
The last two decades have witnessed a huge growth in the demand for geo-spatial data. This demand has encouraged researchers around the world to develop new algorithms and design new mapping systems in order to obtain reliable sources for geo-spatial data. Mobile Mapping Systems (MMS) are one of the main sources for mapping and Geographic Information Systems (GIS) data. MMS integrate various remote sensing sensors, such as cameras and LiDAR, along with navigation sensors to provide the 3D coordinates of points of interest from moving platform (e.g. cars, air planes, etc.). Although MMS can provide accurate mapping solution for different GIS applications, the cost of these systems is not affordable for many users and only large scale companies and institutions can benefits from MMS systems. The main objective of this paper is to propose a new low cost MMS with reasonable accuracy using the available sensors in smartphones and its video camera. Using the smartphone video camera, instead of capturing individual images, makes the system easier to be used by non-professional users since the system will automatically extract the highly overlapping frames out of the video without the user intervention. Results of the proposed system are presented which demonstrate the effect of the number of the used images in mapping solution. In addition, the accuracy of the mapping results obtained from capturing a video is compared to the same results obtained from using separate captured images instead of video.
Geoinformation web-system for processing and visualization of large archives of geo-referenced data
NASA Astrophysics Data System (ADS)
Gordov, E. P.; Okladnikov, I. G.; Titov, A. G.; Shulgina, T. M.
2010-12-01
Developed working model of information-computational system aimed at scientific research in area of climate change is presented. The system will allow processing and analysis of large archives of geophysical data obtained both from observations and modeling. Accumulated experience of developing information-computational web-systems providing computational processing and visualization of large archives of geo-referenced data was used during the implementation (Gordov et al, 2007; Okladnikov et al, 2008; Titov et al, 2009). Functional capabilities of the system comprise a set of procedures for mathematical and statistical analysis, processing and visualization of data. At present five archives of data are available for processing: 1st and 2nd editions of NCEP/NCAR Reanalysis, ECMWF ERA-40 Reanalysis, JMA/CRIEPI JRA-25 Reanalysis, and NOAA-CIRES XX Century Global Reanalysis Version I. To provide data processing functionality a computational modular kernel and class library providing data access for computational modules were developed. Currently a set of computational modules for climate change indices approved by WMO is available. Also a special module providing visualization of results and writing to Encapsulated Postscript, GeoTIFF and ESRI shape files was developed. As a technological basis for representation of cartographical information in Internet the GeoServer software conforming to OpenGIS standards is used. Integration of GIS-functionality with web-portal software to provide a basis for web-portal’s development as a part of geoinformation web-system is performed. Such geoinformation web-system is a next step in development of applied information-telecommunication systems offering to specialists from various scientific fields unique opportunities of performing reliable analysis of heterogeneous geophysical data using approved computational algorithms. It will allow a wide range of researchers to work with geophysical data without specific programming knowledge and to concentrate on solving their specific tasks. The system would be of special importance for education in climate change domain. This work is partially supported by RFBR grant #10-07-00547, SB RAS Basic Program Projects 4.31.1.5 and 4.31.2.7, SB RAS Integration Projects 4 and 9.
An emission-weighted proximity model for air pollution exposure assessment.
Zou, Bin; Wilson, J Gaines; Zhan, F Benjamin; Zeng, Yongnian
2009-08-15
Among the most common spatial models for estimating personal exposure are Traditional Proximity Models (TPMs). Though TPMs are straightforward to configure and interpret, they are prone to extensive errors in exposure estimates and do not provide prospective estimates. To resolve these inherent problems with TPMs, we introduce here a novel Emission Weighted Proximity Model (EWPM) to improve the TPM, which takes into consideration the emissions from all sources potentially influencing the receptors. EWPM performance was evaluated by comparing the normalized exposure risk values of sulfur dioxide (SO(2)) calculated by EWPM with those calculated by TPM and monitored observations over a one-year period in two large Texas counties. In order to investigate whether the limitations of TPM in potential exposure risk prediction without recorded incidence can be overcome, we also introduce a hybrid framework, a 'Geo-statistical EWPM'. Geo-statistical EWPM is a synthesis of Ordinary Kriging Geo-statistical interpolation and EWPM. The prediction results are presented as two potential exposure risk prediction maps. The performance of these two exposure maps in predicting individual SO(2) exposure risk was validated with 10 virtual cases in prospective exposure scenarios. Risk values for EWPM were clearly more agreeable with the observed concentrations than those from TPM. Over the entire study area, the mean SO(2) exposure risk from EWPM was higher relative to TPM (1.00 vs. 0.91). The mean bias of the exposure risk values of 10 virtual cases between EWPM and 'Geo-statistical EWPM' are much smaller than those between TPM and 'Geo-statistical TPM' (5.12 vs. 24.63). EWPM appears to more accurately portray individual exposure relative to TPM. The 'Geo-statistical EWPM' effectively augments the role of the standard proximity model and makes it possible to predict individual risk in future exposure scenarios resulting in adverse health effects from environmental pollution.
NASA Astrophysics Data System (ADS)
Zin, A.; Scotti, M.; Mangolini, E.; Cappelluti, I.; Fiordiponti, R.; Amalric, J.; Flament, P.; Brouillard, E.; Kowaltschek, S.
2015-06-01
The purpose of this paper is to present a viable solution for a low-cost, autonomous GNSS positioning and timing function integrated in the avionics of a GEO telecomm satellite. This paper is based on a study currently carried out by Thales Alenia Space under an ARTES contract with ESA, funded by the Italian Space Agency. The availability of an autonomous means of positioning in GEO platform is essential in reducing the constraints on the ground control. This is even more true in the case of the transfer to the GEO orbit, where the current trend is to implement the low-thrust electrical propulsion and this phase could have a duration of months: the GNSS function can autonomously feed the on-board trajectory propagator with the spacecraft position fixes, in order to constrain the state estimate of the on-board filter. In order to achieve large availability of position and timing of the hosting platform, the tracking of the GNSS antenna side lobes is a critical feature. Based on the recent experiences of SGR GEO, additional insights on the side-lobe levels were made available to the GNSS community and this allows to better target a receiver architecture whose performance can be more precisely determined for the study case. This paper will show the findings in terms of GNSS function architecture for the GEO application, as well as the integration of this function inside the avionic computer. The focus is on a single frequency receiver, targeting at least GPS L1 and Galileo E1 signals. Optimizations in terms of sharing of HW resources with the on-board computer (oscillator, DC/DC converter) and the overall redundancy strategy are presented. Extension and implications for covering to the GTO case is presented as well. The expected receiver performances (position and timing accuracy, autonomy) are provided through in-orbit simulations, including a realistic receiver model.
Querying Patterns in High-Dimensional Heterogenous Datasets
ERIC Educational Resources Information Center
Singh, Vishwakarma
2012-01-01
The recent technological advancements have led to the availability of a plethora of heterogenous datasets, e.g., images tagged with geo-location and descriptive keywords. An object in these datasets is described by a set of high-dimensional feature vectors. For example, a keyword-tagged image is represented by a color-histogram and a…
While it has been shown in many settings that both human land use and natural topographic variability influence stream baseflows, their interactions and relative influences have remained unresolved. Our objective was to determine the influence of human land use and watershed geo...
NASA Technical Reports Server (NTRS)
Suarez, Max J. (Editor); Schubert, Siegfried; Rood, Richard
1995-01-01
The primary objective of the three-day workshop on results from the Data Assimilation Office (DAO) five-year assimilation was to provide timely feedback from the data users concerning the strengths and weaknesses of version 1 of the Goddard Earth Observing System (GEOS-1) assimilated products. A second objective was to assess user satisfaction with the current methods of data access and retrieval. There were a total of 49 presentations, with about half (23) of the presentations from scientists from outside of Goddard. The first two days were devoted to applications of data: studies of the energy diagnostics, precipitation and diabatic heating, hydrological modeling and moisture transport, cloud forcing and validation, various aspects of intraseasonal, seasonal, and interannual variability, ocean wind stress applications, and validation of surface fluxes. The last day included talks from the National Meteorological Center (NMC), the National Center for Atmospheric Research (NCAR), the Center for Ocean-Land-Atmosphere Studies (COLA), the United States Navy, and the European Center for Medium Range Weather Forecasts (ECMWF).
Combined Use of Airborne Lidar and DBInSAR Data to Estimate LAI in Temperate Mixed Forests
NASA Technical Reports Server (NTRS)
Peduzzi, Alicia; Wynne, Randolph Hamilton; Thomas, Valerie A.; Nelson, Ross F.; Reis, James J.; Sanford, Mark
2012-01-01
The objective of this study was to determine whether leaf area index (LAI) in temperate mixed forests is best estimated using multiple-return airborne laser scanning (lidar) data or dual-band, single-pass interferometric synthetic aperture radar data (from GeoSAR) alone, or both in combination. In situ measurements of LAI were made using the LiCor LAI-2000 Plant Canopy Analyzer on 61 plots (21 hardwood, 36 pine, 4 mixed pine hardwood; stand age ranging from 12-164 years; mean height ranging from 0.4 to 41.2 m) in the Appomattox-Buckingham State Forest, Virginia, USA. Lidar distributional metrics were calculated for all returns and for ten one meter deep crown density slices (a new metric), five above and five below the mode of the vegetation returns for each plot. GeoSAR metrics were calculated from the X-band backscatter coefficients (four looks) as well as both X- and P-band interferometric heights and magnitudes for each plot. Lidar metrics alone explained 69% of the variability in LAI, while GeoSAR metrics alone explained 52%. However, combining the lidar and GeoSAR metrics increased the R2 to 0.77 with a CV-RMSE of 0.42. This study indicates the clear potential for X-band backscatter and interferometric height (both now available from spaceborne sensors), when combined with small-footprint lidar data, to improve LAI estimation in temperate mixed forests.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Blyth, Alec; Ben Belfadhel, Mahrez; Hirschorn, Sarah
2013-07-01
The Nuclear Waste Management Organization (NWMO) is responsible for implementing Adaptive Phased Management (APM), the approach selected by the Government of Canada for long-term management of used nuclear fuel generated by Canadian nuclear reactors. The ultimate objective of APM is the centralized containment and isolation of Canada's used nuclear fuel in a Deep Geological Repository in a suitable rock formation at a depth of approximately 500 meters (m) (1,640 feet [ft]). In May 2010, the NWMO published a nine-step site selection process that serves as the road map to decision-making on the location for the deep geological repository. The safetymore » and appropriateness of any potential site will be assessed against a number of factors, both technical and social in nature. The selected site will be one that can be demonstrated to be able to safely contain and isolate used nuclear fuel, protecting humans and the environment over the very long term. The geo-scientific suitability of potential candidate sites will be assessed in a stepwise manner following a progressive and thorough site evaluation process that addresses a series of geo-scientific factors revolving around five safety functions. The geo-scientific site evaluation process includes: Initial Screenings; Preliminary Assessments; and Detailed Site Evaluations. As of November 2012, 22 communities have entered the site selection process (three in northern Saskatchewan and 18 in northwestern and southwestern Ontario). (authors)« less
NASA Astrophysics Data System (ADS)
Koshiishi, H.; Kimoto, Y.; Matsumoto, H.; Goka, T.
The Tsubasa satellite developed by the Japan Aerospace Exploration Agency was launched in Feb 2002 into Geo-stationary Transfer Orbit GTO Perigee 500km Apogee 36000km and had been operated well until Sep 2003 The objective of this satellite was to verify the function of commercial parts and new technologies of bus-system components in space Thus the on-board experiments were conducted in the more severe radiation environment of GTO rather than in Geo-stationary Earth Orbit GEO or Low Earth Orbit LEO The Space Environment Data Acquisition equipment SEDA on board the Tsubasa satellite had the Single-event Upset Monitor SUM and the DOSimeter DOS to evaluate influences on electronic devices caused by radiation environment that was also measured by the particle detectors of the SEDA the Standard DOse Monitor SDOM for measurements of light particles and the Heavy Ion Telescope HIT for measurements of heavy ions The SUM monitored single-event upsets and single-event latch-ups occurred in the test sample of two 64-Mbit DRAMs The DOS measured accumulated radiation dose at fifty-six locations in the body of the Tsubasa satellite Using the data obtained by these instruments single-event and total-dose effects in GTO during solar-activity maximum period especially their rapid changes due to solar flares and CMEs in the region from L 1 1 through L 11 is discussed in this paper
A framework for activity detection in wide-area motion imagery
DOE Office of Scientific and Technical Information (OSTI.GOV)
Porter, Reid B; Ruggiero, Christy E; Morrison, Jack D
2009-01-01
Wide-area persistent imaging systems are becoming increasingly cost effective and now large areas of the earth can be imaged at relatively high frame rates (1-2 fps). The efficient exploitation of the large geo-spatial-temporal datasets produced by these systems poses significant technical challenges for image and video analysis and data mining. In recent years there has been significant progress made on stabilization, moving object detection and tracking and automated systems now generate hundreds to thousands of vehicle tracks from raw data, with little human intervention. However, the tracking performance at this scale, is unreliable and average track length is much smallermore » than the average vehicle route. This is a limiting factor for applications which depend heavily on track identity, i.e. tracking vehicles from their points of origin to their final destination. In this paper we propose and investigate a framework for wide-area motion imagery (W AMI) exploitation that minimizes the dependence on track identity. In its current form this framework takes noisy, incomplete moving object detection tracks as input, and produces a small set of activities (e.g. multi-vehicle meetings) as output. The framework can be used to focus and direct human users and additional computation, and suggests a path towards high-level content extraction by learning from the human-in-the-loop.« less
High resolution earth observation from geostationary orbit by optical aperture synthesys
NASA Astrophysics Data System (ADS)
Mesrine, M.; Thomas, E.; Garin, S.; Blanc, P.; Alis, C.; Cassaing, F.; Laubier, D.
2017-11-01
In this paper, we describe Optical Aperture Synthesis (OAS) imaging instrument concepts studied by Alcatel Alenia Space under a CNES R&T contract in term of technical feasibility. First, the methodology to select the aperture configuration is proposed, based on the definition and quantification of image quality criteria adapted to an OAS instrument for direct imaging of extended objects. The following section presents, for each interferometer type (Michelson and Fizeau), the corresponding optical configurations compatible with a large field of view from GEO orbit. These optical concepts take into account the constraints imposed by the foreseen resolution and the implementation of the co-phasing functions. The fourth section is dedicated to the analysis of the co-phasing methodologies, from the configuration deployment to the fine stabilization during observation. Finally, we present a trade-off analysis allowing to select the concept wrt mission specification and constraints related to instrument accommodation under launcher shroud and in-orbit deployment.
NASA Astrophysics Data System (ADS)
Bilen, S. G.; Anandakrishnan, S.; Urbina, J. V.
2012-12-01
In an effort to provide new and improved geophysical sensing capabilities for the study of ice sheets in Antarctica and Greenland, or to study mountain glaciers, we are developing a network of wirelessly interconnected seismic and GPS sensor nodes (called "geoPebbles"), with the primary objective of making such instruments more capable and cost effective. We describe our design methodology, which has enabled us to develop these state-of-the art sensors using commercial-off-the-shelf hardware combined with custom-designed hardware and software. Each geoPebble is a self-contained, wirelessly connected sensor for collecting seismic measurements and position information. Each node is built around a three-component seismic recorder, which includes an amplifier, filter, and 24-bit analog-to-digital card that can sample up to 10 kHz. Each unit also includes a microphone channel to record the ground-coupled airwave. The timing for each node is available through a carrier-phase measurement of the L1 GPS signal at an absolute accuracy of better than a microsecond. Each geoPebble includes 16 GB of solid-state storage, wireless communications capability to a central supervisory unit, and auxiliary measurements capability (up to eight 10-bit channels at low sample rates). We will report on current efforts to test this new instrument and how we are addressing the challenges imposed by the extreme weather conditions on the Antarctic continent. After fully validating its operational conditions, the geoPebble system will be available for NSF-sponsored glaciology research projects. Geophysical experiments in the polar region are logistically difficult. With the geoPebble system, the cost of doing today's experiments (low-resolution, 2D) will be significantly reduced, and the cost and feasibility of doing tomorrow's experiments (integrated seismic, positioning, 3D, etc.) will be reasonable. Sketch of an experiment with geoPebbles scattered on the surface of the ice sheet. The seismic source can move through the array. The SQC node communicates with all the elements in the array.
Cloud Computing for Geosciences--GeoCloud for standardized geospatial service platforms (Invited)
NASA Astrophysics Data System (ADS)
Nebert, D. D.; Huang, Q.; Yang, C.
2013-12-01
The 21st century geoscience faces challenges of Big Data, spike computing requirements (e.g., when natural disaster happens), and sharing resources through cyberinfrastructure across different organizations (Yang et al., 2011). With flexibility and cost-efficiency of computing resources a primary concern, cloud computing emerges as a promising solution to provide core capabilities to address these challenges. Many governmental and federal agencies are adopting cloud technologies to cut costs and to make federal IT operations more efficient (Huang et al., 2010). However, it is still difficult for geoscientists to take advantage of the benefits of cloud computing to facilitate the scientific research and discoveries. This presentation reports using GeoCloud to illustrate the process and strategies used in building a common platform for geoscience communities to enable the sharing, integration of geospatial data, information and knowledge across different domains. GeoCloud is an annual incubator project coordinated by the Federal Geographic Data Committee (FGDC) in collaboration with the U.S. General Services Administration (GSA) and the Department of Health and Human Services. It is designed as a staging environment to test and document the deployment of a common GeoCloud community platform that can be implemented by multiple agencies. With these standardized virtual geospatial servers, a variety of government geospatial applications can be quickly migrated to the cloud. In order to achieve this objective, multiple projects are nominated each year by federal agencies as existing public-facing geospatial data services. From the initial candidate projects, a set of common operating system and software requirements was identified as the baseline for platform as a service (PaaS) packages. Based on these developed common platform packages, each project deploys and monitors its web application, develops best practices, and documents cost and performance information. This paper presents the background, architectural design, and activities of GeoCloud in support of the Geospatial Platform Initiative. System security strategies and approval processes for migrating federal geospatial data, information, and applications into cloud, and cost estimation for cloud operations are covered. Finally, some lessons learned from the GeoCloud project are discussed as reference for geoscientists to consider in the adoption of cloud computing.
NASA Orbital Debris Large-Object Baseline Population in ORDEM 3.0
NASA Technical Reports Server (NTRS)
Krisco, Paula H.; Vavrin, A. B.; Anz-Meador, P. D.
2013-01-01
The NASA Orbital Debris Program Office (ODPO) has created and validated high fidelity populations of the debris environment for the latest Orbital Debris Engineering Model (ORDEM 3.0). Though the model includes fluxes of objects 10 um and larger, this paper considers particle fluxes for 1 cm and larger debris objects from low Earth orbit (LEO) through Geosynchronous Transfer Orbit (GTO). These are validated by several reliable radar observations through the Space Surveillance Network (SSN), Haystack, and HAX radars. ORDEM 3.0 populations were designed for the purpose of assisting, debris researchers and sensor developers in planning and testing. This environment includes a background derived from the LEO-to-GEO ENvironment Debris evolutionary model (LEGEND) with a Bayesian rescaling as well as specific events such as the FY-1C anti-satellite test, the Iridium 33/Cosmos 2251 accidental collision, and the Soviet/Russian Radar Ocean Reconnaissance Satellite (RORSAT) sodium-potassium droplet releases. The environment described in this paper is the most realistic orbital debris population larger than 1 cm, to date. We describe derivations of the background population and added specific populations. We present sample validation charts of our 1 cm and larger LEO population against Space Surveillance Network (SSN), Haystack, and HAX radar measurements.
Insight into unusual impurity absorbability of GeO(2) in GeO(2)∕Ge stacks.
Ogawa, Shingo; Suda, Taichi; Yamamoto, Takashi; Kutsuki, Katsuhiro; Hideshima, Iori; Hosoi, Takuji; Shimura, Takayoshi; Watanabe, Heiji
2011-10-03
Adsorbed species and its diffusion behaviors in GeO(2)∕Ge stacks, which are future alternative metal-oxide-semiconductor (MOS) materials, have been investigated using various physical analyses. We clarified that GeO(2) rapidly absorbs moisture in air just after its exposure. After the absorbed moisture in GeO(2) reaches a certain limit, the GeO(2) starts to absorb some organic molecules, which is accompanied by a structural change in GeO(2) to form a partial carbonate or hydroxide. We also found that the hydrogen distribution in GeO(2) shows intrinsic characteristics, indicative of different diffusion behaviors at the surface and at the GeO(2)∕Ge interface. Because the impurity absorbability of GeO(2) has a great influence on the electrical properties in Ge-MOS devices, these results provide valuable information in realizing high quality GeO(2)∕Ge stacks for the actual use of Ge-MOS technologies.
NASA Astrophysics Data System (ADS)
Fawkes, S.
This paper compares and contrasts the characteristics of the first space race, which ran from the late 1950s to the late 1990s, and the second space race that began with the successful space flight of SpaceShipOne in 2004. The first space race was between superpowers seeking to establish geo-political dominance in the Cold War. The second space race will be between competing companies seeking to establish low cost access to space for ordinary people. The first space race achieved its geo- political objectives but did not open up low cost access to space but rather restricted access to a select few, highly trained astronauts and cosmonauts. The second space race, driven by the size and growth of the travel and tourism industry, promises to open up access to space to millions of space tourists.
Morgan Receives 2013 Paul G. Silver Award for Outstanding Scientific Service: Response
NASA Astrophysics Data System (ADS)
Morgan, Julia K.
2014-09-01
Thank you, Kelin, for your kind words and nomination, and thanks to the Tectonophysics, Seismology, and Geodesy sections for extending this honor. I also want to recognize the efforts of so many others who really drove the GeoPRISMS program; my job was primarily as a facilitator, channeling the great ideas of the community into distinctive scientific opportunities benefiting a large number of researchers, and what a creative, energetic, and generous community it is. It has been particularly satisfying to watch GeoPRISMS grow during my term as chair, especially with the enthusiastic involvement of the students and early-career researchers who are the future of the program.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang Shengkai; Department of Materials Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656; CREST, Japan Science and Technology Agency
2012-08-06
GeO disproportionation into GeO{sub 2} and Ge is studied through x-ray photoelectron spectroscopy. Direct evidence for the reaction 2GeO {yields} GeO{sub 2} + Ge after annealing in ultra-high vacuum is presented. Activation energy for GeO disproportionation is found to be about 0.7 {+-} 0.2 eV through kinetic and thermodynamic calculations. A kinetic model of GeO disproportionation is established by considering oxygen transfer in the GeO network. The relationship between GeO disproportionation and GeO desorption induced by GeO{sub 2}/Ge interfacial reaction is discussed, and the apparent contradiction between GeO desorption via interfacial redox reaction and GeO disproportionation into Ge and GeO{submore » 2} is explained by considering the oxygen vacancy.« less
NASA Astrophysics Data System (ADS)
Kumer, J. B.; Rairden, R. L.; Polonsky, I. N.; O'Brien, D. M.
2014-12-01
The Tropospheric Infrared Mapping Spectrometer (TIMS) unit rebuilt to operate in a narrow spectral region, approximately 1603 to 1615 nm, of the weak CO2 band as described by Kumer et al. (2013, Proc. SPIE 8867, doi:10.1117/12.2022668) was used to conduct the demonstration. An integrating sphere (IS), linear polarizers and quarter wave plate were used to confirm that the instrument's spectral response to unpolarized light, to 45° linearly polarized light and to circular polarized light are identical. In all these cases the intensity components Ip = Is where Ip is the component parallel to the object space projected slit and Is is perpendicular to the slit. In the circular polarized case Ip = Is in the time averaged sense. The polarizer and IS were used to characterize the ratio Rθ of the instrument response to linearly polarized light at the angle θ relative to parallel from the slit, for increments of θ from 0 to 90°, to that of the unpolarized case. Spectra of diffusely reflected sunlight passed through the polarizer in increments of θ, and divided by the respective Rθ showed identical results, within the noise limit, for solar spectrum multiplied by the atmospheric transmission and convolved by the Instrument Line Shape (ILS). These measurements demonstrate that unknown polarization in the diffusely reflected sunlight on this small spectral range affect only the slow change across the narrow band in spectral response relative to that of unpolarized light and NOT the finely structured / high contrast spectral structure of the CO2 atmospheric absorption that is used to retrieve the atmospheric content of CO2. The latter is one of the geoCARB mission objectives (Kumer et al, 2013). The situation is similar for the other three narrow geoCARB bands; O2 A band 757.9 to 768.6 nm; strong CO2 band 2045.0 to 2085.0 nm; CH4 and CO region 2300.6 to 2345.6 nm. Polonsky et al have repeated the mission simulation study doi:10.5194/amt-7-959-2014 assuming no use of a geoCARB depolarizer or polarizer. Enabled by measurement of the geoCARB grating efficiencies the simulated intensities Ism include the slow polarization induced spectral change across the band. These Ism are input to the retrieval SW that was used in the original study. There is no significant change to the very positive previous results for the mission objective of gas column retrieval.
NASA Astrophysics Data System (ADS)
Huang, Haifeng; Long, Jingjing; Yi, Wu; Yi, Qinglin; Zhang, Guodong; Lei, Bangjun
2017-11-01
In recent years, unmanned aerial vehicles (UAVs) have become widely used in emergency investigations of major natural hazards over large areas; however, UAVs are less commonly employed to investigate single geo-hazards. Based on a number of successful investigations in the Three Gorges Reservoir area, China, a complete UAV-based method for performing emergency investigations of single geo-hazards is described. First, a customized UAV system that consists of a multi-rotor UAV subsystem, an aerial photography subsystem, a ground control subsystem and a ground surveillance subsystem is described in detail. The implementation process, which includes four steps, i.e., indoor preparation, site investigation, on-site fast processing and application, and indoor comprehensive processing and application, is then elaborated, and two investigation schemes, automatic and manual, that are used in the site investigation step are put forward. Moreover, some key techniques and methods - e.g., the layout and measurement of ground control points (GCPs), route planning, flight control and image collection, and the Structure from Motion (SfM) photogrammetry processing - are explained. Finally, three applications are given. Experience has shown that using UAVs for emergency investigation of single geo-hazards greatly reduces the time, intensity and risks associated with on-site work and provides valuable, high-accuracy, high-resolution information that supports emergency responses.
GEO Debris and Interplanetary Dust: Fluxes and Charging Behavior
NASA Astrophysics Data System (ADS)
Graps, A. L.; Green, S. F.; McBride, N. M.; McDonnell, J. A. M.; Drolshagen, G.; Svedhem, H.; Bunte, K. D.
2005-08-01
A population of cosmic dust mixed with a population of man-made debris exists within the Earth's magnetosphere. Measurements of these provide the data samples for studies of the interplanetary dust particles that travel through our magnetosphere from the outside and for studies of the local byproducts of our space endeavours. Even though instruments to detect natural meteoroids and space debris particles have been flown in Low Earth Orbits (LEO) and on interplanetary missions, very little information on the particle environment for Earth orbits above about 600 km altitude have been available. In particular, knowledge about particles smaller than 1 m in the geostationary (GEO) region was largely unknown before GORID. In September 1996, a dust/debris detector: GORID was launched into GEO as a piggyback instrument on the Russian Express-2 telecommunications spacecraft. The instrument began its normal operation in April 1997 and ended its mission in July 2002. The goal of this work was to use GORID's particle data to identify and separate the space debris from the interplanetary dust particles (IDPs) in GEO, to more finely determine the instrument's measurement characteristics and to derive impact fluxes. Here we present some results of that study. We give GORID flux distributions for debris and IDPs and then present intriguing debris clustering features that might be the result of electrostatic fragmentation of the rocket slag particles.
Demonstrating Acquisition of Real-Time Thermal Data Over Fires Utilizing UAVs
NASA Technical Reports Server (NTRS)
Ambrosia, Vincent G.; Wegener, Steven S.; Brass, James A.; Buechel, Sally W.; Peterson, David L. (Technical Monitor)
2002-01-01
A disaster mitigation demonstration, designed to integrate remote-piloted aerial platforms, a thermal infrared imaging payload, over-the-horizon (OTH) data telemetry and advanced image geo-rectification technologies was initiated in 2001. Project FiRE incorporates the use of a remotely piloted Uninhabited Aerial Vehicle (UAV), thermal imagery, and over-the-horizon satellite data telemetry to provide geo-corrected data over a controlled burn, to a fire management community in near real-time. The experiment demonstrated the use of a thermal multi-spectral scanner, integrated on a large payload capacity UAV, distributing data over-the-horizon via satellite communication telemetry equipment, and precision geo-rectification of the resultant data on the ground for data distribution to the Internet. The use of the UAV allowed remote-piloted flight (thereby reducing the potential for loss of human life during hazardous missions), and the ability to "finger and stare" over the fire for extended periods of time (beyond the capabilities of human-pilot endurance). Improved bit-rate capacity telemetry capabilities increased the amount, structure, and information content of the image data relayed to the ground. The integration of precision navigation instrumentation allowed improved accuracies in geo-rectification of the resultant imagery, easing data ingestion and overlay in a GIS framework. We focus on these technological advances and demonstrate how these emerging technologies can be readily integrated to support disaster mitigation and monitoring strategies regionally and nationally.
Graphics Processing Unit (GPU) Acceleration of the Goddard Earth Observing System Atmospheric Model
NASA Technical Reports Server (NTRS)
Putnam, Williama
2011-01-01
The Goddard Earth Observing System 5 (GEOS-5) is the atmospheric model used by the Global Modeling and Assimilation Office (GMAO) for a variety of applications, from long-term climate prediction at relatively coarse resolution, to data assimilation and numerical weather prediction, to very high-resolution cloud-resolving simulations. GEOS-5 is being ported to a graphics processing unit (GPU) cluster at the NASA Center for Climate Simulation (NCCS). By utilizing GPU co-processor technology, we expect to increase the throughput of GEOS-5 by at least an order of magnitude, and accelerate the process of scientific exploration across all scales of global modeling, including: The large-scale, high-end application of non-hydrostatic, global, cloud-resolving modeling at 10- to I-kilometer (km) global resolutions Intermediate-resolution seasonal climate and weather prediction at 50- to 25-km on small clusters of GPUs Long-range, coarse-resolution climate modeling, enabled on a small box of GPUs for the individual researcher After being ported to the GPU cluster, the primary physics components and the dynamical core of GEOS-5 have demonstrated a potential speedup of 15-40 times over conventional processor cores. Performance improvements of this magnitude reduce the required scalability of 1-km, global, cloud-resolving models from an unfathomable 6 million cores to an attainable 200,000 GPU-enabled cores.
NASA Astrophysics Data System (ADS)
Wang, Jun; Xu, Xiaoguang; Henze, Daven K.; Zeng, Jing; Ji, Qiang; Tsay, Si-Chee; Huang, Jianping
2012-04-01
Predicting the influences of dust on atmospheric composition, climate, and human health requires accurate knowledge of dust emissions, but large uncertainties persist in quantifying mineral sources. This study presents a new method for combined use of satellite-measured radiances and inverse modeling to spatially constrain the amount and location of dust emissions. The technique is illustrated with a case study in May 2008; the dust emissions in Taklimakan and Gobi deserts are spatially optimized using the GEOS-Chem chemical transport model and its adjoint constrained by aerosol optical depth (AOD) that are derived over the downwind dark-surface region in China from MODIS (Moderate Resolution Imaging Spectroradiometer) reflectance with the aerosol single scattering properties consistent with GEOS-chem. The adjoint inverse modeling yields an overall 51% decrease in prior dust emissions estimated by GEOS-Chem over the Taklimakan-Gobi area, with more significant reductions south of the Gobi Desert. The model simulation with optimized dust emissions shows much better agreement with independent observations from MISR (Multi-angle Imaging SpectroRadiometer) AOD and MODIS Deep Blue AOD over the dust source region and surface PM10 concentrations. The technique of this study can be applied to global multi-sensor remote sensing data for constraining dust emissions at various temporal and spatial scales, and hence improving the quantification of dust effects on climate, air quality, and human health.
NASA Technical Reports Server (NTRS)
Holdaway, Daniel; Kent, James
2015-01-01
The linearity of a selection of common advection schemes is tested and examined with a view to their use in the tangent linear and adjoint versions of an atmospheric general circulation model. The schemes are tested within a simple offline one-dimensional periodic domain as well as using a simplified and complete configuration of the linearised version of NASA's Goddard Earth Observing System version 5 (GEOS-5). All schemes which prevent the development of negative values and preserve the shape of the solution are confirmed to have nonlinear behaviour. The piecewise parabolic method (PPM) with certain flux limiters, including that used by default in GEOS-5, is found to support linear growth near the shocks. This property can cause the rapid development of unrealistically large perturbations within the tangent linear and adjoint models. It is shown that these schemes with flux limiters should not be used within the linearised version of a transport scheme. The results from tests using GEOS-5 show that the current default scheme (a version of PPM) is not suitable for the tangent linear and adjoint model, and that using a linear third-order scheme for the linearised model produces better behaviour. Using the third-order scheme for the linearised model improves the correlations between the linear and non-linear perturbation trajectories for cloud liquid water and cloud liquid ice in GEOS-5.
Big Data challenges and solutions in building the Global Earth Observation System of Systems (GEOSS)
NASA Astrophysics Data System (ADS)
Mazzetti, Paolo; Nativi, Stefano; Santoro, Mattia; Boldrini, Enrico
2014-05-01
The Group on Earth Observation (GEO) is a voluntary partnership of governments and international organizations launched in response to calls for action by the 2002 World Summit on Sustainable Development and by the G8 (Group of Eight) leading industrialized countries. These high-level meetings recognized that international collaboration is essential for exploiting the growing potential of Earth observations to support decision making in an increasingly complex and environmentally stressed world. To this aim is constructing the Global Earth Observation System of Systems (GEOSS) on the basis of a 10-Year Implementation Plan for the period 2005 to 2015 when it will become operational. As a large-scale integrated system handling large datasets as those provided by Earth Observation, GEOSS needs to face several challenges related to big data handling and big data infrastructures management. Referring to the traditional multiple Vs characteristics of Big Data (volume, variety, velocity, veracity and visualization) it is evident how most of them can be found in data handled by GEOSS. In particular, concerning Volume, Earth Observation already generates a large amount of data which can be estimated in the range of Petabytes (1015 bytes), with Exabytes (1018) already targeted. Moreover, the challenge is related not only to the data size, but also to the large amount of datasets (not necessarily having a big size) that systems need to manage. Variety is the other main challenge since datasets coming from different sensors, processed for different use-cases are published with highly heterogeneous metadata and data models, through different service interfaces. Innovative multidisciplinary applications need to access and use those datasets in a harmonized way. Moreover Earth Observation data are growing in size and variety at an exceptionally fast rate and new technologies and applications, including crowdsourcing, will even increase data volume and variety in the next future. The current implementation of GEOSS already addresses several big data challenges. In particular, the brokered architecture adopted in the GEOSS Common Infrastructure with the deployment of the GEO DAB (Discovery and Access Broker) allows to connect more than 20 big EO infrastructures while keeping them autonomous as required by their own mandate and governance. They make more than 60 million of unique resources discoverable and accessible through the GEO Portal. Through the GEO DAB, users are able to seamlessly discover resources provided by different infrastructures, and access them in a harmonized way, collecting datasets from different sources on a Common Environment (same coordinate reference system, spatial subset, format, etc.). Through the GEONETCast system, GEOSS is also providing a solution related to the Velocity challenge, for delivering EO resources to developing countries with low bandwidth connections. Several researches addressing other Big data Vs challenges in GEOSS are on-going, including quality representation for Veracity (as in the FP7 GeoViQua project), brokering big data analytics platforms for Velocity, and support of other EO resources for Variety (such as modelling resources in the Model Web).
Analysis of soil samples from Gebeng area using NAA technique
NASA Astrophysics Data System (ADS)
Elias, Md Suhaimi; Wo, Yii Mei; Hamzah, Mohd Suhaimi; Shukor, Shakirah Abd; Rahman, Shamsiah Ab; Salim, Nazaratul Ashifa Abdullah; Azman, Muhamad Azfar; Hashim, Azian
2017-01-01
Rapid development and urbanization will increase number of residence and industrial area. Without proper management and control of pollution, these will give an adverse effect to environment and human life. The objective of this study to identify and quantify key contaminants into the environment of the Gebeng area as a result of industrial and human activities. Gebeng area was gazetted as one of the industrial estate in Pahang state. Assessment of elemental pollution in soil of Gebeng area base on level of concentration, enrichment factor and geo-accumulation index. The enrichment factors (EFs) were determined by the elemental rationing method, whilst the geo-accumulation index (Igeo) by comparing of current to continental crustal average concentration of element. Twenty-seven of soil samples were collected from Gebeng area. Soil samples were analysed by using Neutron Activation Analyses (NAA) technique. The obtained data showed higher concentration of iron (Fe) due to abundance in soil compared to other elements. The results of enrichment factor showed that Gebeng area have enrich with elements of As, Br, Hf, Sb, Th and U. Base on the geo-accumulation index (Igeo) classification, the soil quality of Gebeng area can be classified as class 0, (uncontaminated) to Class 3, (moderately to heavily contaminated).
Grobusch, Martin P.; Gautret, Philippe; Kuhn, Susan; Lim, Poh Lian; Yates, Johnnie; McCarthy, Anne E.; Rothe, Camilla; Kato, Yasuyuki; Huber, Kristina; Schwartz, Eli; Shaw, Marc T. M.; Rapp, Christophe; Blumberg, Lucille; Jensenius, Mogens; van Genderen, Perry J. J.
2017-01-01
Background Zika virus (ZIKV) was first isolated in Africa; decades later, caused large outbreaks in the Pacific, and is considered endemic in Asia. We aim to describe ZIKV disease epidemiology outside the Americas, the importance of travelers as sentinels of disease transmission, and discrepancies in travel advisories from major international health organizations. Methods and findings This descriptive analysis using GeoSentinel Surveillance Network records involves sixty-four travel and tropical medicine clinics in 29 countries. Ill returned travelers with a confirmed or probable diagnosis of ZIKV disease acquired in Africa, Asia and the Pacific seen between 1 January 2012 and 31 December 2016 are included, and the frequencies of demographic, trip, and diagnostic characteristics described. ZIKV was acquired in Asia (18), the Pacific (10) and Africa (1). For five countries (Indonesia, Philippines, Thailand, Vietnam, Cameroon), GeoSentinel patients were sentinel markers of recent Zika activity. Additionally, the first confirmed ZIKV infection acquired in Kiribati was reported to GeoSentinel (2015), and a probable case was reported from Timor Leste (April 2016), representing the only case known to date. Review of Zika situation updates from major international health authorities for country risk classifications shows heterogeneity in ZIKV country travel advisories. Conclusions Travelers are integral to the global spread of ZIKV, serving as sentinel markers of disease activity. Although GeoSentinel data are collected by specialized clinics and do not capture all imported cases, we show that surveillance of imported infections by returned travelers augments local surveillance system data regarding ZIKV epidemiology and can assist with risk categorization by international authorities. However, travel advisories are variable due to risk uncertainties. PMID:28973011
The Geochemical Databases GEOROC and GeoReM - What's New?
NASA Astrophysics Data System (ADS)
Sarbas, B.; Jochum, K. P.; Nohl, U.; Weis, U.
2017-12-01
The geochemical databases GEOROC (http: georoc.mpch-mainz.gwdg.de) and GeoReM (http: georem.mpch-mainz.gwdg.de) are maintained by the Max Planck Institute for Chemistry in Mainz, Germany. Both online databases became crucial tools for geoscientists from different research areas. They are regularly upgraded by new tools and new data from recent publications obtained from a wide range of international journals. GEOROC is a collection of published analyses of volcanic rocks and mantle xenoliths. Since recently, data for plutonic rocks are added. The analyses include major and trace element concentrations, radiogenic and non-radiogenic isotope ratios as well as analytical ages for whole rocks, glasses, minerals and inclusions. Samples come from eleven geological settings and span the whole geological age scale from Archean to Recent. Metadata include, among others, geographic location, rock class and rock type, geological age, degree of alteration, analytical method, laboratory, and reference. The GEOROC web page allows selection of samples by geological setting, geography, chemical criteria, rock or sample name, and bibliographic criteria. In addition, it provides a large number of precompiled files for individual locations, minerals and rock classes. GeoReM is a database collecting information about reference materials of geological and environmental interest, such as rock powders, synthetic and natural glasses as well as mineral, isotopic, biological, river water and seawater reference materials. It contains published data and compilation values (major and trace element concentrations and mass fractions, radiogenic and stable isotope ratios). Metadata comprise, among others, uncertainty, analytical method and laboratory. Reference materials are important for calibration, method validation, quality control and to establish metrological traceability. GeoReM offers six different search strategies: samples or materials (published values), samples (GeoReM preferred values), chemical criteria, chemical criteria based on bibliography, bibliography, as well as methods and institutions.
NASA Astrophysics Data System (ADS)
Doelling, David R.; Bhatt, Rajendra; Haney, Conor O.; Gopalan, Arun; Scarino, Benjamin R.
2017-09-01
The new 3rd generation geostationary (GEO) imagers will have many of the same NPP-VIIRS imager spectral bands, thereby offering the opportunity to apply the VIIRS cloud, aerosol, and land use retrieval algorithms on the new GEO imager measurements. Climate quality retrievals require multi-channel calibrated radiances that are stable over time. The deep convective cloud calibration technique (DCCT) is a large ensemble statistical technique that assumes that the DCC reflectance is stable over time. Because DCC are found in sufficient numbers across all GEO domains, they provide a uniform calibration stability evaluation across the GEO constellation. The baseline DCCT has been successful in calibrating visible and near-infrared channels. However, for shortwave infrared (SWIR) channels the DCCT is not as effective to monitor radiometric stability. The DCCT was optimized as a function wavelength in this paper. For SWIR bands, the greatest reduction of the DCC response trend standard error was achieved through deseasonalization. This is effective because the DCC reflectance exhibits small regional seasonal cycles that can be characterized on a monthly basis. On the other hand, the inter-annually variability in DCC response was found to be extremely small. The Met-9 0.65-μm channel DCC response was found to have a 3% seasonal cycle. Deseasonalization reduced the trend standard error from 1% to 0.4%. For the NPP-VIIRS SWIR bands, deseasonalization reduced the trend standard error by more than half. All VIIRS SWIR band trend standard errors were less than 1%. The DCCT should be able to monitor the stability of all GEO imager solar reflective bands across the tropical domain with the same uniform accuracy.
Leder, Karin; Grobusch, Martin P; Gautret, Philippe; Chen, Lin H; Kuhn, Susan; Lim, Poh Lian; Yates, Johnnie; McCarthy, Anne E; Rothe, Camilla; Kato, Yasuyuki; Bottieau, Emmanuel; Huber, Kristina; Schwartz, Eli; Stauffer, William; Malvy, Denis; Shaw, Marc T M; Rapp, Christophe; Blumberg, Lucille; Jensenius, Mogens; van Genderen, Perry J J; Hamer, Davidson H
2017-01-01
Zika virus (ZIKV) was first isolated in Africa; decades later, caused large outbreaks in the Pacific, and is considered endemic in Asia. We aim to describe ZIKV disease epidemiology outside the Americas, the importance of travelers as sentinels of disease transmission, and discrepancies in travel advisories from major international health organizations. This descriptive analysis using GeoSentinel Surveillance Network records involves sixty-four travel and tropical medicine clinics in 29 countries. Ill returned travelers with a confirmed or probable diagnosis of ZIKV disease acquired in Africa, Asia and the Pacific seen between 1 January 2012 and 31 December 2016 are included, and the frequencies of demographic, trip, and diagnostic characteristics described. ZIKV was acquired in Asia (18), the Pacific (10) and Africa (1). For five countries (Indonesia, Philippines, Thailand, Vietnam, Cameroon), GeoSentinel patients were sentinel markers of recent Zika activity. Additionally, the first confirmed ZIKV infection acquired in Kiribati was reported to GeoSentinel (2015), and a probable case was reported from Timor Leste (April 2016), representing the only case known to date. Review of Zika situation updates from major international health authorities for country risk classifications shows heterogeneity in ZIKV country travel advisories. Travelers are integral to the global spread of ZIKV, serving as sentinel markers of disease activity. Although GeoSentinel data are collected by specialized clinics and do not capture all imported cases, we show that surveillance of imported infections by returned travelers augments local surveillance system data regarding ZIKV epidemiology and can assist with risk categorization by international authorities. However, travel advisories are variable due to risk uncertainties.
An Interative Grahical User Interface for Maritime Security Services
NASA Astrophysics Data System (ADS)
Reize, T.; Müller, R.; Kiefl, R.
2013-10-01
In order to analyse optical satellite images for maritime security issues in Near-Real-Time (NRT) an interactive graphical user interface (GUI) based on NASA World Wind was developed and is presented in this article. Targets or activities can be detected, measured and classified with this tool simply and quickly. The service uses optical satellite images, currently taken from 6 sensors: Worldview-1 and Worldview-2, Ikonos, Quickbird, GeoEye-1 and EROS-B. The GUI can also handle SAR-images, air-borne images or UAV images. Software configurations are provided in a job-order file and thus all preparation tasks, such as image installation are performed fully automatically. The imagery can be overlaid with vessels derived by an automatic detection processor. These potential vessel layers can be zoomed in by a single click and sorted with an adapted method. Further object properties, such as vessel type or confidence level of identification, can be added by the operator manually. The heading angle can be refined by dragging the vessel's head or switching it to 180° with a single click. Further vessels or other relevant objects can be added. The objects length, width, heading and position are calculated automatically from three clicks on top, bottom and an arbitrary point at one of the object's longer side. In case of an Activity Detection, the detected objects can be grouped in area of interests (AOI) and classified, according to the ordered activities. All relevant information is finally written to an exchange file, after quality control and necessary correction procedures are performed. If required, image thumbnails can be cut around objects or around whole areas of interest and saved as separated, geo-referenced images.
United Kingdom Infrared Telescope's Spectrograph Observations of Human-Made Space Objects
NASA Technical Reports Server (NTRS)
Buckalew, Brent; Abercromby, Kira; Lederer, Susan; Cowardin, Heather; Frith, James
2017-01-01
Presented here are the results of the United Kingdom Infrared Telescope (UKIRT) spectral observations of human-made space objects taken from 2014 to 2015. The data collected using the UKIRT 1-5 micron Imager Spectrometer (UIST) cover the wavelength range 0.7-2.5 micrometers. Overall, data were collected on 18 different orbiting objects at or near geosynchronous orbit (GEO). Two of the objects are controlled spacecraft, twelve are non-controlled spacecraft, one is a rocket body, and three are cataloged as debris. The remotely collected data are compared to the laboratory-collected reflectance data on typical spacecraft materials; thereby general materials are identified but not specific types. These results highlight the usefulness of observations in the infrared by focusing on features from hydrocarbons and silicon. The spacecraft, both the controlled and non-controlled, show distinct features due to the presence of solar panels whereas the rocket bodies do not. Signature variations between rocket bodies, due to the presence of various metals and paints on their surfaces, show a clear distinction from those objects with solar panels, demonstrating that one can distinguish most spacecraft from rocket bodies through infrared spectrum analysis. Finally, the debris pieces tend to show featureless, dark spectra. These results show that the laboratory data in its current state give well-correlated indications as to the nature of the surface materials on the objects. Further telescopic data collection and model updates to include noise, surface roughness, and material degradation are necessary to make better assessments of orbital object material types. A comparison conducted between objects observed previously with the NASA Infrared Telescope Facility (IRTF) shows similar materials and trends from the two telescopes and different times. However, based on the current state of the model, infrared spectroscopic data are adequate to classify objects in GEO as spacecraft, rocket bodies, or debris.
A Geo-Distributed System Architecture for Different Domains
NASA Astrophysics Data System (ADS)
Moßgraber, Jürgen; Middleton, Stuart; Tao, Ran
2013-04-01
The presentation will describe work on the system-of-systems (SoS) architecture that is being developed in the EU FP7 project TRIDEC on "Collaborative, Complex and Critical Decision-Support in Evolving Crises". In this project we deal with two use-cases: Natural Crisis Management (e.g. Tsunami Early Warning) and Industrial Subsurface Development (e.g. drilling for oil). These use-cases seem to be quite different at first sight but share a lot of similarities, like managing and looking up available sensors, extracting data from them and annotate it semantically, intelligently manage the data (big data problem), run mathematical analysis algorithms on the data and finally provide decision support on this basis. The main challenge was to create a generic architecture which fits both use-cases. The requirements to the architecture are manifold and the whole spectrum of a modern, geo-distributed and collaborative system comes into play. Obviously, one cannot expect to tackle these challenges adequately with a monolithic system or with a single technology. Therefore, a system architecture providing the blueprints to implement the system-of-systems approach has to combine multiple technologies and architectural styles. The most important architectural challenges we needed to address are 1. Build a scalable communication layer for a System-of-sytems 2. Build a resilient communication layer for a System-of-sytems 3. Efficiently publish large volumes of semantically rich sensor data 4. Scalable and high performance storage of large distributed datasets 5. Handling federated multi-domain heterogeneous data 6. Discovery of resources in a geo-distributed SoS 7. Coordination of work between geo-distributed systems The design decisions made for each of them will be presented. These developed concepts are also applicable to the requirements of the Future Internet (FI) and Internet of Things (IoT) which will provide services like smart grids, smart metering, logistics and environmental monitoring.
Enhanced Detection of Sea-Disposed Man-Made Objects in Backscatter Data
NASA Astrophysics Data System (ADS)
Edwards, M.; Davis, R. B.
2016-12-01
The Hawai'i Undersea Military Munitions Assessment (HUMMA) project developed software to increase data visualization capabilities applicable to seafloor reflectivity datasets acquired by a variety of bottom-mapping sonar systems. The purpose of these improvements is to detect different intensity values within an arbitrary amplitude range that may be associated with relative target reflectivity as well as extend the overall amplitude range across which detailed dynamic contrast may be effectively displayed. The backscatter dataset used to develop this software imaged tens of thousands of reflective targets resting on the seabed that were systematically sea disposed south of Oahu, Hawaii, around the end of World War II in waters ranging from 300-600 meters depth. Human-occupied and remotely operated vehicles conducted ground-truth video and photographic reconnaissance of thousands of these reflective targets, documenting and geo-referencing long curvilinear trials of items including munitions, paint cans, airplane parts, scuttled ships, cars and bundled anti-submarine nets. Edwards et al. [2012] determined that most individual trails consist of objects of one particular type. The software described in this presentation, in combination with the ground-truth images, was developed to help recognize different types of objects based on reflectivity, size, and shape from altitudes of tens of meters above the seabed. The fundamental goal of the software is to facilitate rapid underway detection and geo-location of specific sea-disposed objects so their impact on the environment can be assessed.
The Cultural Legacies of Slavery in Virginia: Advancing Geo-Literacy in an Interdisciplinary Context
ERIC Educational Resources Information Center
Finn, John C.; Mazzocca, Ann E.; Goetz, Evan; Gibson, Lisa
2015-01-01
In this special section of "The Geography Teacher" the authors report on two Virginia Geographic Alliance-sponsored workshops that they convened during the spring semester of 2014. The central objective of these workshops was to bring pre-service education students in Virginia together with social studies teachers from around the state…
The Assessment of Mangrove Sediment Quality in Mengkabong Lagoon: An Index Analysis Approach
ERIC Educational Resources Information Center
Praveena, Sarva M.; Radojevic, Miroslav; Abdullah, Mohd H.
2007-01-01
The objectives of this study are to use different types of indexes to assess the current pollution status in Mengkabong lagoon and select the best index to describe the Mengkabong sediment quality. The indexes used in this study were Enrichment Factor (EF), Geo-accumulation Index (Igeo), Pollution Load Index (PLI) and Marine Sediment Pollution…
ERIC Educational Resources Information Center
Titova, Svetlana
2014-01-01
Mobile devices can enhance learning experience in many ways: provide instant feedback and better diagnosis of learning problems; enhance learner autonomy; create mobile networking collaboration; help design enquiry-based activities based on augmented reality, geo-location awareness and video-capture. One of the main objectives of the international…
ERIC Educational Resources Information Center
Morris, Phillip; Thrall, Grant
2010-01-01
Geographic analysis has been adopted by businesses, especially the retail sector, since the early 1990s (Thrall, 2002). Institutional research can receive the same benefits businesses have by adopting geographic analysis and technology. The commonalities between businesses and higher education institutions include the existence of trade areas, the…
Wivell, Charles E.; Olmsted, Coert; Steinwand, Daniel R.; Taylor, Christopher
1993-01-01
Because the pixel location in a line of Synthetic Aperture Radar (SAR) image data is directly related to the distance the pixel is from the radar, terrain elevations cause large displacement errors in the geo-referenced location of the pixel. This is especially true for radar systems with small angles between the nadir and look vectors. Thus, to geo-register a SAR image accurately, the terrain of the area must be taken into account. (Curlander et al., 1987; Kwok et al., 1987, Schreier et al., 1990; Wivell et al., 1992). As part of the 1992 National Aeronautics and Space Administration's Earth Observing System Version 0 activities, a prototype SAR geocod-. ing and terrain correction system was developed at the US. Geological Survey's (USGS) E~os Data Center (EDC) in Sioux Falls, South Dakota. Using this system with 3-arc-second digital elevation models (DEMs) mosaicked at the ED^ Alaska Field Office, 21 ERS-I s.4~ scenes acquired at the Alaska SAR Facility were automatically geocoded, terrain corrected, and mosaicked. The geo-registered scenes were mosaicked using a simple concatenation.
Earth Observations, Models and Geo-Design in Support of SDG Implementation and Monitoring
NASA Astrophysics Data System (ADS)
Plag, H. P.; Jules-Plag, S.
2016-12-01
Implementation and Monitoring of the United Nations' Sustainable Development Goals (SDGs) requires support from Earth observation and scientific communities. Applying a goal-based approach to determine the data needs to the Targets and Indicators associated with the SDGs demonstrates that integration of environmental with socio-economic and statistical data is required. Large data gaps exist for the built environment. A Geo-Design platform can provide the infrastructure and conceptual model for the data integration. The development of policies and actions to foster the implementation of SDGs in many cases requires research and the development of tools to answer "what if" questions. Here, agent-based models and model webs combined with a Geo-Design platform are promising avenues. This advanced combined infrastructure can also play a crucial role in the necessary capacity building. We will use the example of SDG 5 (Gender equality) to illustrate these approaches. SDG 11 (Sustainable Cities and Communities) is used to underline the cross-goal linkages and the joint benefits of Earth observations, data integration, and modeling tools for multiple SDGs.
Users Manual for the Geospatial Stream Flow Model (GeoSFM)
Artan, Guleid A.; Asante, Kwabena; Smith, Jodie; Pervez, Md Shahriar; Entenmann, Debbie; Verdin, James P.; Rowland, James
2008-01-01
The monitoring of wide-area hydrologic events requires the manipulation of large amounts of geospatial and time series data into concise information products that characterize the location and magnitude of the event. To perform these manipulations, scientists at the U.S. Geological Survey Center for Earth Resources Observation and Science (EROS), with the cooperation of the U.S. Agency for International Development, Office of Foreign Disaster Assistance (USAID/OFDA), have implemented a hydrologic modeling system. The system includes a data assimilation component to generate data for a Geospatial Stream Flow Model (GeoSFM) that can be run operationally to identify and map wide-area streamflow anomalies. GeoSFM integrates a geographical information system (GIS) for geospatial preprocessing and postprocessing tasks and hydrologic modeling routines implemented as dynamically linked libraries (DLLs) for time series manipulations. Model results include maps that depicting the status of streamflow and soil water conditions. This Users Manual provides step-by-step instructions for running the model and for downloading and processing the input data required for initial model parameterization and daily operation.
A GEOS-Based OSSE for the "MISTiC Winds" Concept
NASA Technical Reports Server (NTRS)
McCarty, W.; Blaisdell, J.; Fuentes, M.; Carvalho, D.; Errico, R.; Gelaro, R.; Kouvaris, L.; Moradi, I.; Pawson, S.; Prive, N.;
2018-01-01
The Goddard Earth Observing System (GEOS) atmospheric model and data assimilation system are used to perform an Observing System Simulation Experiment (OSSE) for the proposed MISTiC Wind mission. The GEOS OSSE includes a reference simulation (the Nature Run), from which the pseudo-observations are generated. These pseuo-observations span the entire suite of in-situ and space space-based observations presently used in operational weather prediction, with the addition of the MISTiC-Wind dataset. New observation operators have been constructed for the MISTiC Wind data, including both the radiances measured in the 4-micron part of the solar spectrum and the winds derived from these radiances. The OSSE examines the impacts on global forecast skill of adding these observations to the current operational suite, showing substantial improvements in forecasts when the wind information are added. It is shown that a constellation of four MISTiC Wind satellites provides more benefit than a single platform, largely because of the increased accuracy of the feature-derived wind measurements when more platforms are used.
Monitoring Earth's Shortwave Reflectance: GEO Instrument Concept
NASA Technical Reports Server (NTRS)
Brageot, Emily; Mercury, Michael; Green, Robert; Mouroulis, Pantazis; Gerwe, David
2015-01-01
In this paper we present a GEO instrument concept dedicated to monitoring the Earth's global spectral reflectance with a high revisit rate. Based on our measurement goals, the ideal instrument needs to be highly sensitive (SNR greater than 100) and to achieve global coverage with spectral sampling (less than or equal to 10nm) and spatial sampling (less than or equal to 1km) over a large bandwidth (380-2510 nm) with a revisit time (greater than or equal to greater than or equal to 3x/day) sufficient to fully measure the spectral-radiometric-spatial evolution of clouds and confounding factor during daytime. After a brief study of existing instruments and their capabilities, we choose to use a GEO constellation of up to 6 satellites as a platform for this instrument concept in order to achieve the revisit time requirement with a single launch. We derive the main parameters of the instrument and show the above requirements can be fulfilled while retaining an instrument architecture as compact as possible by controlling the telescope aperture size and using a passively cooled detector.
Candidate solar cell materials for photovoltaic conversion in a solar power satellite /SPS/
NASA Technical Reports Server (NTRS)
Glaser, P. E.; Almgren, D. W.
1978-01-01
In recognition of the obstacles to solar-generated baseload power on earth, proposals have been made to locate solar power satellites in geosynchronous earth orbit (GEO), where solar energy would be available 24 hours a day during most of the time of the year. In an SPS, the electricity produced by solar energy conversion will be fed to microwave generators forming part of a planar phase-array transmitting antenna. The antenna is designed to precisely direct a microwave beam of very low intensity to one or more receiving antennas at desired locations on earth. At the receiving antenna, the microwave energy will be safely and efficiently reconverted to electricity and then be transmitted to consumers. An SPS system will include a number of satellites in GEO. Attention is given to the photovoltaic option for solar energy conversion in GEO, solar cell requirements, the availability of materials, the implication of large production volumes, requirements for high-volume manufacture of solar cell arrays, and the effects of concentration ratio on solar cell array area.
Alaska GeoFORCE, A New Geologic Adventure in Alaska
NASA Astrophysics Data System (ADS)
Wartes, D.
2011-12-01
RAHI, the Rural Alaska Honors Institute is a statewide, six-week, summer college-preparatory bridge program at the University of Alaska Fairbanks for Alaska Native and rural high school juniors and seniors. A program of rigorous academic activity combines with social, cultural, and recreational activities. Students are purposely stretched beyond their comfort levels academically and socially to prepare for the big step from home or village to a large culturally western urban campus. This summer RAHI is launching a new program, GeoFORCE Alaska. This outreach initiative is designed to increase the number and diversity of students pursuing STEM degree programs and entering the future high-tech workforce. It uses Earth science as the hook because most kids get excited about dinosaurs, volcanoes and earthquakes, but it includes physics, chemistry, math, biology and other sciences. Students will be recruited, initially from the Arctic North Slope schools, in the 8th grade to begin the annual program of approximately 8 days, the summer before their 9th grade year and then remain in the program for all four years of high school. They must maintain a B or better grade average and participate in all GeoFORCE events. The carrot on the end of the stick is an exciting field event each summer. Over the four-year period, events will include trips to Fairbanks, Arizona, Oregon and the Appalachians. All trips are focused on Earth science and include a 100+ page guidebook, with tests every night culminating with a final exam. GeoFORCE Alaska is being launched by UAF in partnership with the University of Texas at Austin, which has had tremendous success with GeoFORCE Texas. GeoFORCE Alaska will be managed by UAF's long-standing Rural Alaska Honors Insitute (RAHI) that has been successfully providing intense STEM educational opportunities for Alaskan high school students for almost 30 years. The Texas program, with adjustments for differences in culture and environment, will be replicated in Alaska, with plans to begin with 40 rising 9th graders during the summer of 2012. The program will continue to add a new cohort of 9th graders each year for the next four years. By the summer of 2015, GeoFORCE Alaska is targeting a capacty of 160 students in grades 9th through 12th.
Regional uncertainty of GOSAT XCO2 retrievals in China: quantification and attribution
NASA Astrophysics Data System (ADS)
Bie, Nian; Lei, Liping; Zeng, ZhaoCheng; Cai, Bofeng; Yang, Shaoyuan; He, Zhonghua; Wu, Changjiang; Nassar, Ray
2018-03-01
The regional uncertainty of the column-averaged dry air mole fraction of CO2 (XCO2) retrieved using different algorithms from the Greenhouse gases Observing SATellite (GOSAT) and its attribution are still not well understood. This paper investigates the regional performance of XCO2 within a latitude band of 37-42° N segmented into 8 cells in a grid of 5° from west to east (80-120° E) in China, where typical land surface types and geographic conditions exist. The former includes desert, grassland and built-up areas mixed with cropland; and the latter includes anthropogenic emissions that change from small to large from west to east, including those from the megacity of Beijing. For these specific cells, we evaluate the regional uncertainty of GOSAT XCO2 retrievals by quantifying and attributing the consistency of XCO2 retrievals from four algorithms (ACOS, NIES, OCFP and SRFP) by intercomparison. These retrievals are then specifically compared with simulated XCO2 from the high-resolution nested model in East Asia of the Goddard Earth Observing System 3-D chemical transport model (GEOS-Chem). We also introduce the anthropogenic CO2 emissions data generated from the investigation of surface emitting point sources that was conducted by the Ministry of Environmental Protection of China to GEOS-Chem simulations of XCO2 over the Chinese mainland. The results indicate that (1) regionally, the four algorithms demonstrate smaller absolute biases of 0.7-1.1 ppm in eastern cells, which are covered by built-up areas mixed with cropland with intensive anthropogenic emissions, than those in the western desert cells (1.0-1.6 ppm) with a high-brightness surface from the pairwise comparison results of XCO2 retrievals. (2) Compared with XCO2 simulated by GEOS-Chem (GEOS-XCO2), the XCO2 values from ACOS and SRFP have better agreement, while values from OCFP are the least consistent with GEOS-XCO2. (3) Viewing attributions of XCO2 in the spatio-temporal pattern, ACOS and SRFP demonstrate similar patterns, while OCFP is largely different from the others. In conclusion, the discrepancy in the four algorithms is the smallest in eastern cells in the study area, where the megacity of Beijing is located and where there are strong anthropogenic CO2 emissions, which implies that XCO2 from satellite observations could be reliably applied in the assessment of atmospheric CO2 enhancements induced by anthropogenic CO2 emissions. The large inconsistency among the four algorithms presented in western deserts which displays a high albedo and dust aerosols, moreover, demonstrates that further improvement is still necessary in such regions, even though many algorithms have endeavored to minimize the effects of aerosols scattering and surface albedo.
Federal Geographic Data Committee, U.S. Geological Survey
1993-01-01
The first National Geo-Data Policy Forum was held on May 10-12, 1993, in Tyson's Corner, Virginia. The objective of the National Geo-Data Policy Forum was to examine policies related to the evolution and use of the National Spatial Data Infrastructure (NSDI). A second goal was to identify issues concerning spatial data technology and its use by all citizens. Policy makers from the public and private sectors offered ideas on the myriad issues and questions related to the NSDI and learned of concerns that their organizations must address. The links that connect the NSDI to the Clinton Administration's National Information Infrastructure were identified and discussed. The forum offered participants an opportunity to define the NSDI's role in carrying out technology policy.
Protecting the GEO Environment: Policies and Practices
NASA Technical Reports Server (NTRS)
Johnson, Nicholas L.; McKay, Gordon A. (Technical Monitor)
1999-01-01
The geosynchronous orbital regime has long been recognized as a unique space resource, dictating special measures to ensure its continuing use for future generations. During the past 20 years a variety of national and international policies have been developed to preserve this environment. A review of current practices involving the deployment and disposal of geosynchronous spacecraft, associated upper stages and apogee kick motors, and geosynchronous orbit transfer objects indicates both positive and negative trends. Most spacecraft operators are indeed performing end-of-mission maneuvers, but the boost altitudes normally fall short of policy guidelines. Russia, a major operator in geosynchronous orbit, maneuvers only 1 in 3 spacecraft out of the region, while China has never refired a spacecraft above GEO. The viability of voluntary protection measures for this regime depends upon the responsible actions of the aerospace community as a whole.
Affordable In-Space Transportation
NASA Technical Reports Server (NTRS)
Curtis, L. A.; VanDyke, M. K.; Lajoie, R. M.; Woodcock, G. R.
1996-01-01
Current and proposed launch systems will provide access to low-Earth orbit (LEO), and destinations beyond LEO, but the cost of delivering payloads will preclude the use of these services by many users. To develop and encourage revolutionary commercial utilization of geosynchronous orbit (GEO) and to provide an affordable means to continue NASA space science and exploration missions, the transportation costs to in-space destinations must be reduced. The principal objective of this study was to conceptually define three to four promising approaches to in-space transportation for delivery of satellites and other payloads, 3,000- to 10,000-lb class, to GEO destinations. This study established a methodology for evaluating in-space transportation systems based on life-cycle cost. The reusable concepts seemed to fare better in the evaluation than expendable, since a major driver in the life-cycle cost was the stage production cost.
Atmospheric Science Data Center
2018-05-16
ISCCP-D2like-GEO Ed3A Project Title: CERES Discipline: ... Order Data Guide Documents: GEO Description/Abstract Detailed CERES ISCCP-D2like Product ... Data Products Catalog: DPC_ISCCP-D2like-GEO_R5V3 (PDF) Readme Files: Readme GEO R5-987 ...
A flexible telecom satellite repeater based on microwave photonic technologies
NASA Astrophysics Data System (ADS)
Sotom, Michel; Benazet, Benoît; Maignan, Michel
2017-11-01
Future telecom satellite based on geo-stationary Earth orbit (GEO) will require advanced payloads in Kaband so as to receive, route and re-transmit hundreds of microwave channels over multiple antenna beams. We report on the proof-of-concept demonstration of a analogue repeater making use of microwave photonic technologies for supporting broadband, transparent, and flexible cross-connectivity. It has microwave input and output sections, and features a photonic core for LO distribution, frequency down-conversion, and cross-connection of RF channels. With benefits such as transparency to RF frequency, infinite RF isolation, mass and volume savings, such a microwave photonic cross-connect would compare favourably with microwave implementations, and based on optical MEMS switches could grow up to large port counts.
Communication missions for geostationary platforms
NASA Astrophysics Data System (ADS)
Iida, Takashi; Shimada, Masaaki; Yoshimoto, Shigetoshi; Suzuki, Yoshiaki; Hashimoto, Kazuhiko
1986-12-01
It is estimated that several thousand transponders will be needed in the 36 MHz slot by the year 2000 by the U.S. and Japan, while the GEO position above the U.S. will be congested and the slot above Japan is shared by the Soviets. Additional demands may arise from the development of mobile communications services in Japan and the U.S. A large GEO platform could benefit from the economies of scale by making servicing an economical prospect. The platform could carry 50/40 GHz antennas for personal radio communications, multibeam DBS antennas, a mobile telephone system functioning at 900/800 MHz, a relay station for earth-moon communications, and global data relay system. The limitations and necessary operational parameters of each system are examined.
NASA Technical Reports Server (NTRS)
Li, Zhao; Molod, Andrea; Schubert, Siegfried
2018-01-01
Reliable prediction of precipitation remains one of the most pivotal and complex challenges in seasonal forecasting. Previous studies show that various large-scale climate modes, such as ENSO, PNA and NAO play significant role in winter precipitation variability over the Northern America. The influences are most pronounced in years of strong indices of such climate modes. This study evaluates model bias, predictability and forecast skills of monthly winter precipitation in GEOS5-S2S 2.0 retrospective forecast from 1981 to 2016, with emphasis on the forecast skill of precipitation over North America during the extreme events of ENSO, PNA and NAO by applying EOF and composite analysis.
Rahmati, Omid; Tahmasebipour, Naser; Haghizadeh, Ali; Pourghasemi, Hamid Reza; Feizizadeh, Bakhtiar
2017-02-01
Despite the importance of soil erosion in sustainable development goals in arid and semi-arid areas, the study of the geo-environmental conditions and factors influencing gully erosion occurrence is rarely undertaken. As effort to this challenge, the main objective of this study is to apply an integrated approach of Geographic Object-Based Image Analysis (GEOBIA) together with high-spatial resolution imagery (SPOT-5) for detecting gully erosion features at the Kashkan-Poldokhtar watershed, Iran. We also aimed to apply a Conditional Probability (CP) model for establishing the spatial relationship between gullies and the Geo-Environmental Factors (GEFs). The gully erosion inventory map prepared using GEOBIA and field surveying was randomly partitioned into two subsets: (1) part 1 that contains 70% was used in the training phase of the CP model; (2) part 2 is a validation dataset (30%) for validation of the model and to confirm its accuracy. Prediction performances of the GEOBIA and CP model were checked by overall accuracy and Receiver Operating Characteristics (ROC) curve methods, respectively. In addition, the influence of all GEFs on gully erosion was evaluated by performing a sensitivity analysis model. The validation findings illustrated that overall accuracy for GEOBIA approach and the area under the ROC curve for the CP model were 92.4% and 89.9%, respectively. Also, based on sensitivity analysis, soil texture, drainage density, and lithology represent significantly effects on the gully erosion occurrence. This study has shown that the integrated framework can be successfully used for modeling gully erosion occurrence in a data-poor environment. Copyright © 2016 Elsevier B.V. All rights reserved.
Simulation analysis of photometric data for attitude estimation of unresolved space objects
NASA Astrophysics Data System (ADS)
Du, Xiaoping; Gou, Ruixin; Liu, Hao; Hu, Heng; Wang, Yang
2017-10-01
The attitude information acquisition of unresolved space objects, such as micro-nano satellites and GEO objects under the way of ground-based optical observations, is a challenge to space surveillance. In this paper, a useful method is proposed to estimate the SO attitude state according to the simulation analysis of photometric data in different attitude states. The object shape model was established and the parameters of the BRDF model were determined, then the space object photometric model was established. Furthermore, the photometric data of space objects in different states are analyzed by simulation and the regular characteristics of the photometric curves are summarized. The simulation results show that the photometric characteristics are useful for attitude inversion in a unique way. Thus, a new idea is provided for space object identification in this paper.
NASA Astrophysics Data System (ADS)
Ozturk, D.; Chaudhary, A.; Votava, P.; Kotfila, C.
2016-12-01
Jointly developed by Kitware and NASA Ames, GeoNotebook is an open source tool designed to give the maximum amount of flexibility to analysts, while dramatically simplifying the process of exploring geospatially indexed datasets. Packages like Fiona (backed by GDAL), Shapely, Descartes, Geopandas, and PySAL provide a stack of technologies for reading, transforming, and analyzing geospatial data. Combined with the Jupyter notebook and libraries like matplotlib/Basemap it is possible to generate detailed geospatial visualizations. Unfortunately, visualizations generated is either static or does not perform well for very large datasets. Also, this setup requires a great deal of boilerplate code to create and maintain. Other extensions exist to remedy these problems, but they provide a separate map for each input cell and do not support map interactions that feed back into the python environment. To support interactive data exploration and visualization on large datasets we have developed an extension to the Jupyter notebook that provides a single dynamic map that can be managed from the Python environment, and that can communicate back with a server which can perform operations like data subsetting on a cloud-based cluster.
Quality of service management framework for dynamic chaining of geographic information services
NASA Astrophysics Data System (ADS)
Onchaga, Richard
2006-06-01
Dynamic chaining of geographic information services (geo-services) is gaining popularity as a new paradigm for evolving flexible geo-information systems and for providing on-demand access to geo-information. In dynamic chaining, disparate geo-services are discovered and composed at run time to yield more elaborate functionality and create value-added geo-information. Common approaches to service chaining discover and compose disparate geo-services based on the functional capability of individual geo-services. The primary concern of common approaches is thus the emergent behavior of the resulting composite geo-service. However, as geo-services become mundane and take on a greater and more strategic role in mission critical processes, deliverable quality of service (QoS) becomes an important concern. QoS concerns operational characteristics of a service that determine its utility in an application context. To address pertinent QoS requirements, a new approach to service chaining becomes necessary. In this paper we propose a QoS-aware chaining approach in which geo-services are discovered, composed and executed considering both functional and QoS requirements. We prescribe a QoS management framework that defines fundamental principles, concepts and mechanisms which can be applied to evolve an effective distributed computing platform for QoS-aware chaining of geo-services - the so-called geo-service infrastructure. The paper also defines an extensible QoS model for services delivered by dynamic compositions of geo-services. The process of orthophoto generation is used to demonstrate the applicability of the prescribed framework to service-oriented geographic information processing.
Oliveira, Lucas Pires Garcia; Conte, Fernanda Lopes; Cardoso, Eliza de Oliveira; Conti, Bruno José; Santiago, Karina Basso; Golim, Marjorie de Assis; Cruz, Maria Teresa; Sforcin, José Maurício
2016-12-01
Geopropolis (GEO) in combination with doxorubicin (DOX) reduced HEp-2 cells viability compared to GEO and DOX alone. A possible effect of this combination on the innate immunity could take place, and its effects were analysed on THP-1 cell - a human leukaemia monocytic cell line used as a model to study monocyte activity and macrophage activity, assessing cell viability, expression of cell markers and cytokine production. THP-1 cells were incubated with GEO, DOX and their combination. Cell viability was assessed by MTT assay, cell markers expression by flow cytometry and cytokine production by ELISA. GEO + DOX did not affect cell viability. GEO alone or in combination increased TLR-4 and CD80 but not HLA-DR and TLR-2 expression. GEO stimulated TNF-α production while DOX alone or in combination did not affect it. GEO alone or in combination inhibited IL-6 production. GEO exerted a pro-inflammatory profile by increasing TLR-4 and CD80 expression and TNF-α production, favouring the activation of the immune/inflammatory response. GEO + DOX did not affect cell viability and presented an immunomodulatory action. Lower concentrations of DOX combined to GEO could be used in cancer patients, avoiding side effects and benefiting from the biological properties of GEO. © 2016 Royal Pharmaceutical Society.
NASA Astrophysics Data System (ADS)
Dawson, M.
2011-12-01
GeoCorps America, a program of the Geological Society of America's (GSA) Education and Outreach Department, provides short-term geoscience jobs in America's most amazing public lands. These jobs are hosted on federal lands managed by GeoCorps' three partner agencies: the National Park Service (NPS), the U.S. Forest Service (USFS), and the Bureau of Land Management (BLM). Agency staff submit to GSA position descriptions that help meet their geoscience needs. GSA advertises the positions online, recruits applicants from its 24,000+ members, and coordinates the placement of the candidates selected by agency staff. The typical GeoCorps position lasts for three months, pays a stipend of $2,750, and provides either free housing or a housing allowance. Some GeoCorps positions are classified as "Guest Scientist" positions, which generally last longer, involve larger payments, and require a higher level of expertise. Most GeoCorps positions occur during the spring/summer, but an increasing number of positions are being offered during the fall/winter. GeoCorps positions are open to geoscientists of all levels, from undergraduates through retired professionals. GeoCorps projects involve field and laboratory-based geoscience research, but some projects focus on developing educational programs and materials for staff, volunteers, and the public. The subject areas covered by GeoCorps projects include geology, hydrology, paleontology, mapping/GIS, soils, geo-hazards, cave/karst science, and more. GeoCorps positions have taken place at over 125 different locations nationwide, including Grand Canyon National Park, Sierra National Forest, and Craters of the Moon National Monument. In 2011, GeoCorps began offering GeoCorps Diversity Internships and GeoCorps American Indian Internships. The introduction of these programs doubled the level of diversity among GeoCorps participants. This increase in diversity is helping GSA and its partner agencies in meeting its mutual goal of broadening participation in the field of geoscience. Over the next few years, GeoCorps aims to further increase its diversity, add more partner groups (such as USGS), and continue to provide inspiring educational and professional development opportunities for geoscientists of all levels.
GeoChronos: An On-line Collaborative Platform for Earth Observation Scientists
NASA Astrophysics Data System (ADS)
Gamon, J. A.; Kiddle, C.; Curry, R.; Markatchev, N.; Zonta-Pastorello, G., Jr.; Rivard, B.; Sanchez-Azofeifa, G. A.; Simmonds, R.; Tan, T.
2009-12-01
Recent advances in cyberinfrastructure are offering new solutions to the growing challenges of managing and sharing large data volumes. Web 2.0 and social networking technologies, provide the means for scientists to collaborate and share information more effectively. Cloud computing technologies can provide scientists with transparent and on-demand access to applications served over the Internet in a dynamic and scalable manner. Semantic Web technologies allow for data to be linked together in a manner understandable by machines, enabling greater automation. Combining all of these technologies together can enable the creation of very powerful platforms. GeoChronos (http://geochronos.org/), part of a CANARIE Network Enabled Platforms project, is an online collaborative platform that incorporates these technologies to enable members of the earth observation science community to share data and scientific applications and to collaborate more effectively. The GeoChronos portal is built on an open source social networking platform called Elgg. Elgg provides a full set of social networking functionalities similar to Facebook including blogs, tags, media/document sharing, wikis, friends/contacts, groups, discussions, message boards, calendars, status, activity feeds and more. An underlying cloud computing infrastructure enables scientists to access dynamically provisioned applications via the portal for visualizing and analyzing data. Users are able to access and run the applications from any computer that has a Web browser and Internet connectivity and do not need to manage and maintain the applications themselves. Semantic Web Technologies, such as the Resource Description Framework (RDF) are being employed for relating and linking together spectral, satellite, meteorological and other data. Social networking functionality plays an integral part in facilitating the sharing of data and applications. Examples of recent GeoChronos users during the early testing phase have included the IAI International Wireless Sensor Networking Summer School at the University of Alberta, and the IAI Tropi-Dry community. Current GeoChronos activities include the development of a web-based spectral library and related analytical and visualization tools, in collaboration with members of the SpecNet community. The GeoChronos portal will be open to all members of the earth observation science community when the project nears completion at the end of 2010.
NASA Astrophysics Data System (ADS)
Osei, Richard
There are many problems associated with operating a data center. Some of these problems include data security, system performance, increasing infrastructure complexity, increasing storage utilization, keeping up with data growth, and increasing energy costs. Energy cost differs by location, and at most locations fluctuates over time. The rising cost of energy makes it harder for data centers to function properly and provide a good quality of service. With reduced energy cost, data centers will have longer lasting servers/equipment, higher availability of resources, better quality of service, a greener environment, and reduced service and software costs for consumers. Some of the ways that data centers have tried to using to reduce energy costs include dynamically switching on and off servers based on the number of users and some predefined conditions, the use of environmental monitoring sensors, and the use of dynamic voltage and frequency scaling (DVFS), which enables processors to run at different combinations of frequencies with voltages to reduce energy cost. This thesis presents another method by which energy cost at data centers could be reduced. This method involves the use of Ant Colony Optimization (ACO) on a Quadratic Assignment Problem (QAP) in assigning user request to servers in geo-distributed data centers. In this paper, an effort to reduce data center energy cost involves the use of front portals, which handle users' requests, were used as ants to find cost effective ways to assign users requests to a server in heterogeneous geo-distributed data centers. The simulation results indicate that the ACO for Optimal Server Activation and Task Placement algorithm reduces energy cost on a small and large number of users' requests in a geo-distributed data center and its performance increases as the input data grows. In a simulation with 3 geo-distributed data centers, and user's resource request ranging from 25,000 to 25,000,000, the ACO algorithm was able to reduce energy cost on an average of $.70 per second. The ACO for Optimal Server Activation and Task Placement algorithm has proven to work as an alternative or improvement in reducing energy cost in geo-distributed data centers.
NASA Astrophysics Data System (ADS)
Cristofoletti, P.; Esposito, A.; Anzidei, M.
2003-04-01
This paper presents the methodologies and issues involved in the use of GIS techniques to manage geodetic information derived from networks in seismic and volcanic areas. Organization and manipulation of different geodetical, geological and seismic database, give us a new challenge in interpretation of information that has several dimensions, including spatial and temporal variations, also the flexibility and brand range of tools available in GeoNetGIS, make it an attractive platform for earthquake risk assessment. During the last decade the use of geodetic networks based on the Global Positioning System, devoted to geophysical applications, especially for crustal deformation monitoring in seismic and volcanic areas, increased dramatically. The large amount of data provided by these networks, combined with different and independent observations, such as epicentre distribution of recent and historical earthquakes, geological and structural data, photo interpretation of aerial and satellite images, can aid for the detection and parameterization of seismogenic sources. In particular we applied our geodetic oriented GIS to a new GPS network recently set up and surveyed in the Central Apennine region: the CA-GeoNet. GeoNetGIS is designed to analyze in three and four dimensions GPS sources and to improve crustal deformation analysis and interpretation related with tectonic structures and seismicity. It manages many database (DBMS) consisting of different classes, such as Geodesy, Topography, Seismicity, Geology, Geography and Raster Images, administrated according to Thematic Layers. GeoNetGIS represents a powerful research tool allowing to join the analysis of all data layers to integrate the different data base which aid for the identification of the activity of known faults or structures and suggesting the new evidences of active tectonics. A new approach to data integration given by GeoNetGIS capabilities, allow us to create and deliver a wide range of maps, digital and 3-dimensional environment data analysis applications for geophysical users and civil defense companies, also distributing them on the World Wide Web or in wireless connection realized by PDA computer. It runs on powerful PC platform under Win2000 Prof OS © and based on ArcGIS 8.2 ESRI © software.
NASA Astrophysics Data System (ADS)
Fayon, A. K.; Eyssautier, C.
2008-12-01
Introductory geoscience courses at large urban institutions have the potential to increase the scientific literacy of the general population. Therefore, engaging all students in the classroom is critical. As instructors of these courses for non-majors, we have all observed students disengaging from the class for a number of reasons. One hypothesis is students feel out of their element in a large, academic institution. This is particularly true for underrepresented minority, low-income first generation, and immigrant college students - the students on one side of the postsecondary science enrollment gap. This research addresses how, through pedagogy and content, we can engage a more diverse population of students by changing their attitudes towards science. We administered the Colorado Learning Attitudes about Science Survey (CLASS) instrument, modified for geology, to students enrolled in introductory geology courses (GEO1001 and PsTL1171) at the University of Minnesota - Twin Cities. This survey consists of 42 questions that measure students" pre- and post-course attitudes towards geology and physical sciences. GEO1001 is a large lecture course where the laboratory content is independent from lecture content. PSTL1171 is offered through the Department of Postsecondary Teaching and Learning; this course has smaller class sizes, and lecture and laboratory content are fully integrated. Demographically, students of color comprise 23% of the student population in GEO1001, in contrast to 73% in PsTL1171. Overall, responses from all students surveyed show a positive shift in attitudes and confidence. However, in comparing responses from only students of color, those enrolled in PsTL1171 demonstrated greater favorable shifts in the categories of personal interests and problem solving confidence. The pre-course responses also indicate that students of color in PsTL1171 started the course with more favorable attitudes towards real world connections than those students in GEO1001. These preliminary survey results reinforce the connection between attitude, confidence, and pedagogy, particularly for underrepresented minority students. Furthermore, the knowledge of increased attitude towards real world connections among students of color can be used in course content development in order to engage a more diverse student population. Future research will address the role of pedagogy on the acquisition and retention of knowledge in these introductory courses.
2008-03-01
Society, Washington DC, 1999. 11. Ferringer, Matthew P. and David B. Spencer . “Satellite Constellation Design Optimization Via Multiple-Objective...5 GA Genetic Algorithms . . . . . . . . . . . . . . . . . . . . . . 5 HEO Highly Elliptical Orbit...and their phasing relationship. He analyzed different combinations of GEO, Highly Elliptical Orbit (HEO)1 and Tundra2 orbits to create a global
Space station systems analysis study. Part 2, Volume 2. [technical report
NASA Technical Reports Server (NTRS)
1977-01-01
Specific system options are defined and identified for a cost effective space station capable of orderly growth with regard to both function and orbit location. Selected program options are analyzed and configuration concepts are developed to meet objectives for the satellite power system, earth servicing, space processing, and supporting activities. Transportation systems are analyzed for both LEO and GEO orbits.
Distortion Representation of Forecast Errors for Model Skill Assessment and Objective Analysis
NASA Technical Reports Server (NTRS)
Hoffman, Ross N.; Nehrkorn, Thomas; Grassotti, Christopher
1998-01-01
We proposed a novel characterization of errors for numerical weather predictions. A general distortion representation allows for the displacement and amplification or bias correction of forecast anomalies. Characterizing and decomposing forecast error in this way has several important applications, including the model assessment application and the objective analysis application. In this project, we have focused on the assessment application, restricted to a realistic but univariate 2-dimensional situation. Specifically, we study the forecast errors of the sea level pressure (SLP), the 500 hPa geopotential height, and the 315 K potential vorticity fields for forecasts of the short and medium range. The forecasts are generated by the Goddard Earth Observing System (GEOS) data assimilation system with and without ERS-1 scatterometer data. A great deal of novel work has been accomplished under the current contract. In broad terms, we have developed and tested an efficient algorithm for determining distortions. The algorithm and constraints are now ready for application to larger data sets to be used to determine the statistics of the distortion as outlined above, and to be applied in data analysis by using GEOS water vapor imagery to correct short-term forecast errors.
3D Geovisualization & Stylization to Manage Comprehensive and Participative Local Urban Plans
NASA Astrophysics Data System (ADS)
Brasebin, M.; Christophe, S.; Jacquinod, F.; Vinesse, A.; Mahon, H.
2016-10-01
3D geo-visualization is more and more used and appreciated to support public participation, and is generally used to present predesigned planned projects. Nevertheless, other participatory processes may benefit from such technology such as the elaboration of urban planning documents. In this article, we present one of the objectives of the PLU++ project: the design of a 3D geo-visualization system that eases the participation concerning local urban plans. Through a pluridisciplinary approach, it aims at covering the different aspects of such a system: the simulation of built configurations to represent regulation information, the efficient stylization of these objects to make people understand their meanings and the interaction between 3D simulation and stylization. The system aims at being adaptive according to the participation context and to the dynamic of the participation. It will offer the possibility to modify simulation results and the rendering styles of the 3D representations to support participation. The proposed 3D rendering styles will be used in a set of practical experiments in order to test and validate some hypothesis from past researches of the project members about 3D simulation, 3D semiotics and knowledge about uses.
Benhaddya, Mohammed Lamine; Boukhelkhal, Abdelaziz; Halis, Youcef; Hadjel, Mohammed
2016-04-01
Hassi Messaoud town is a recent city that is situated inside the oil field, which hosts an important petroleum extraction field and refinery. Large-scale and long-term oil refinery and corresponding industrial activities may contaminate the surrounding soil/dust and could lead to pollution levels that can affect human health. The soil and road dust samples were analysed for different trace elements: copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn). Geo-accumulation index (I(geo)), pollution index (PI), and integrated pollution index (IPI) were calculated to evaluate the heavy metal contamination level of urban soil and road dust. The I(geo) values indicate unpolluted to moderate polluted of investigated metals in the soil samples. The assessment results of PI support the results of I(geo), and IPI indicates heavy metals in road dust polluted seriously. The noncarcinogenic health risk assessment shows that ingestion of soil/dust particles is the route for exposure to heavy metals, followed by dermal adsorption. The human exposure risk assessment based on different exposure pathways showed that the hazard index (HI) was <1.0 for all of the elements. The relative exposure risk (noncarcinogenic) was greater for toddlers. Although the overall risk was within the acceptable limit of 1.00, the HI of Pb from the soil (0.103) and road dust (0.132) was close to the threshold limits, which over the long-term may pose a health risk.
NASA Astrophysics Data System (ADS)
Jin, Shuanggen; Jin, Rui; Kutoglu, H.
2017-06-01
The most intense geomagnetic storm in solar cycle 24 occurred on March 17, 2015, and the detailed ionospheric storm morphologies are difficultly obtained from traditional observations. In this paper, the Geostationary Earth Orbit (GEO) observations of BeiDou Navigation Satellite System (BDS) are for the first time used to investigate the ionospheric responses to the geomagnetic storm. Using BDS GEO and GIMs TEC series, negative and positive responses to the March 2015 storm are found at local and global scales. During the main phase, positive ionospheric storm is the main response to the geomagnetic storm, while in the recovery phase, negative phases are pronounced at all latitudes. Maximum amplitudes of negative and positive phases appear in the afternoon and post-dusk sectors during both main and recovery phases. Furthermore, dual-peak positive phases in main phase and repeated negative phase during the recovery are found from BDS GEO observations. The geomagnetic latitudes corresponding to the maximum disturbances during the main and recovery phases show large differences, but they are quasi-symmetrical between southern and northern hemispheres. No clear zonal propagation of traveling ionospheric disturbances is detected in the GNSS TEC disturbances at high and low latitudes. The thermospheric composition variations could be the dominant source of the observed ionospheric storm effect from GUVI [O]/[N2] ratio data as well as storm-time electric fields. Our study demonstrates that the BDS (especially the GEO) observations are an important data source to observe ionospheric responses to the geomagnetic storm.
Simulation of Aerosols and Chemistry with a Unified Global Model
NASA Technical Reports Server (NTRS)
Chin, Mian
2004-01-01
This project is to continue the development of the global simulation capabilities of tropospheric and stratospheric chemistry and aerosols in a unified global model. This is a part of our overall investigation of aerosol-chemistry-climate interaction. In the past year, we have enabled the tropospheric chemistry simulations based on the GEOS-CHEM model, and added stratospheric chemical reactions into the GEOS-CHEM such that a globally unified troposphere-stratosphere chemistry and transport can be simulated consistently without any simplifications. The tropospheric chemical mechanism in the GEOS-CHEM includes 80 species and 150 reactions. 24 tracers are transported, including O3, NOx, total nitrogen (NOy), H2O2, CO, and several types of hydrocarbon. The chemical solver used in the GEOS-CHEM model is a highly accurate sparse-matrix vectorized Gear solver (SMVGEAR). The stratospheric chemical mechanism includes an additional approximately 100 reactions and photolysis processes. Because of the large number of total chemical reactions and photolysis processes and very different photochemical regimes involved in the unified simulation, the model demands significant computer resources that are currently not practical. Therefore, several improvements will be taken, such as massive parallelization, code optimization, or selecting a faster solver. We have also continued aerosol simulation (including sulfate, dust, black carbon, organic carbon, and sea-salt) in the global model to cover most of year 2002. These results have been made available to many groups worldwide and accessible from the website http://code916.gsfc.nasa.gov/People/Chin/aot.html.
Xie, Jianping; He, Zhili; Liu, Xinxing; Liu, Xueduan; Van Nostrand, Joy D.; Deng, Ye; Wu, Liyou; Zhou, Jizhong; Qiu, Guanzhou
2011-01-01
Acid mine drainage (AMD) is an extreme environment, usually with low pH and high concentrations of metals. Although the phylogenetic diversity of AMD microbial communities has been examined extensively, little is known about their functional gene diversity and metabolic potential. In this study, a comprehensive functional gene array (GeoChip 2.0) was used to analyze the functional diversity, composition, structure, and metabolic potential of AMD microbial communities from three copper mines in China. GeoChip data indicated that these microbial communities were functionally diverse as measured by the number of genes detected, gene overlapping, unique genes, and various diversity indices. Almost all key functional gene categories targeted by GeoChip 2.0 were detected in the AMD microbial communities, including carbon fixation, carbon degradation, methane generation, nitrogen fixation, nitrification, denitrification, ammonification, nitrogen reduction, sulfur metabolism, metal resistance, and organic contaminant degradation, which suggested that the functional gene diversity was higher than was previously thought. Mantel test results indicated that AMD microbial communities are shaped largely by surrounding environmental factors (e.g., S, Mg, and Cu). Functional genes (e.g., narG and norB) and several key functional processes (e.g., methane generation, ammonification, denitrification, sulfite reduction, and organic contaminant degradation) were significantly (P < 0.10) correlated with environmental variables. This study presents an overview of functional gene diversity and the structure of AMD microbial communities and also provides insights into our understanding of metabolic potential in AMD ecosystems. PMID:21097602
GEO/SAMS - The Geostationary Synthetic Aperture Microwave Sounder
NASA Technical Reports Server (NTRS)
Lambrigtsen, Bjorn H.
2008-01-01
The National Oceanic and Atmospheric Administration (NOAA) has for many years operated two weather satellite systems, the Polar-orbiting Operational Environmental Satellite system (POES), using low-earth orbiting (LEO) satellites, and the Geostationary Operational Environmental Satellite system (GOES), using geostationary earth orbiting (GEO) satellites. (Similar systems are also operated by other nations.) The POES satellites have been equipped with both infrared (IR) and microwave (MW) atmospheric sounders, which makes it possible to determine the vertical distribution of temperature and humidity in the troposphere even under cloudy conditions. Such satellite observations have had a significant impact on weather forecasting accuracy, especially in regions where in situ observations are sparse. In contrast, the GOES satellites have only been equipped with IR sounders, since it has not been feasible to build a large enough antenna to achieve sufficient spatial resolution for a MW sounder in GEO. As a result, GOES soundings can only be obtained in cloud free areas and in the less important upper atmosphere, above the cloud tops. This has hindered the effective use of GOES data in numerical weather prediction. Full sounding capabilities with the GOES system is highly desirable because of the advantageous spatial and temporal coverage that is possible from GEO. While POES satellites provide coverage in relatively narrow swaths, and with a revisit time of 12-24 hours or more, GOES satellites can provide continuous hemispheric coverage, making it possible to monitor highly dynamic phenomena such as hurricanes.
Over the next decade, data requirements to inform air quality management decisions and policies will need to be expanded to large spatial domains to accommodate decisions which more frequently cross geo-political boundaries; from urban (local) and regional scales to regional, sup...
NASA Technical Reports Server (NTRS)
Janz, Scott; Smith, James C.; Mannino, Antonio
2010-01-01
This slide presentation reviews the concepts of the Geostationary Coastal Ecosystem Dynamics Imager (GEO CEDI) which will be used on the GEO Coastal and Air Pollution Events (GEO CAPE) Mission. The primary science requirements require scans of the U.S. Coastal waters 3 times per day during the daylight hours. Included in the overview are presentations about the systems, the optics, the detectors, the mechanical systems, the electromechanical systems, the electrical design, the flight software, the thermal systems, and the contamination prevention requirements.
NASA Technical Reports Server (NTRS)
Lederer, Susan; Cowardin, H. M.; Buckalew, B.; Frith, J.; Hickson, P.; Pace, L.; Matney, M.; Anz-Meador, P.; Seitzer, P.; Stansbery, E.;
2016-01-01
Characterizing debris in Earth-orbit has become increasingly important as the population growth rises steadily, posing greater and greater threats to active satellites with each passing year. Currently, the Joint Space Operations is tracking over 23,000 pieces of debris, ranging in size from 1-meter and larger in geosychronous orbits (GEO) to 10-cm and larger at low-Earth orbits (LEO). Model estimates suggest that there may be more than 500,000 pieces of spacecraft debris larger than 1 cm currently in orbit around the Earth. With such a small fraction of the total population being tracked, and new break-ups occurring in LEO, GEO, and Geo Transfer Orbits, new assets, techniques, and approaches for characterizing this debris are needed. With this in mind, NASA's Orbital Debris Program Office has actively tasked a suite of telescopes around the world. In 2015, the newly-built 1.3m optical Meter Class Autonomous Telescope (MCAT) came on-line on Ascension Island in the South Atlantic Ocean and is currently in its commissioning phase. MCAT is designed to track Earth-orbiting objects above 200km, conduct surveys at GEO, and work in tandem with a newly-installed Raven-class commercial-off-the-shelf system, a 0.4-meter telescope co-located on Ascension with a field-of-view similar to MCAT's and research-grade instrumentation designed to complement MCAT for observations taken either simultaneously or in tandem. The 3.8m infrared UKIRT telescope on Mauna Kea, Hawaii, has been heavily tasked throughout 2015 and into 2016, collecting data on individual targets as well as in survey modes to study both the general GEO population as well as an individual break-up event of a BRIZ-M Rocket body that occurred in January 2016. Data collected include photometry and spectroscopy in the near-Infrared (0.85-2.5 m) and the mid-infrared (8-16 m). Finally, the 6.5-m Baade Magellan telescope at Las Campanas Observatory in Chile was used to collect optical photometric survey data in October 2015 of two GEO Titan breakups, focusing on locations of possible debris concentrations as indicated by the NASA standard break-up model.
a New Object-Based Framework to Detect Shodows in High-Resolution Satellite Imagery Over Urban Areas
NASA Astrophysics Data System (ADS)
Tatar, N.; Saadatseresht, M.; Arefi, H.; Hadavand, A.
2015-12-01
In this paper a new object-based framework to detect shadow areas in high resolution satellite images is proposed. To produce shadow map in pixel level state of the art supervised machine learning algorithms are employed. Automatic ground truth generation based on Otsu thresholding on shadow and non-shadow indices is used to train the classifiers. It is followed by segmenting the image scene and create image objects. To detect shadow objects, a majority voting on pixel-based shadow detection result is designed. GeoEye-1 multi-spectral image over an urban area in Qom city of Iran is used in the experiments. Results shows the superiority of our proposed method over traditional pixel-based, visually and quantitatively.
NASA Astrophysics Data System (ADS)
Feng, L.; Palmer, P. I.; Yang, Y.; Yantosca, R. M.; Kawa, S. R.; Paris, J.-D.; Matsueda, H.; Machida, T.
2010-07-01
We evaluate the GEOS-Chem atmospheric transport model (v8-02-01) of CO2 over 2003-2006, driven by GEOS-4 and GEOS-5 meteorology from the NASA Goddard Global Modelling and Assimilation Office, using surface, aircraft and space-borne concentration measurements of CO2. We use an established ensemble Kalman filter to estimate a posteriori biospheric+biomass burning (BS+BB) and oceanic (OC) CO2 fluxes from 22 geographical regions, following the TransCom 3 protocol, using boundary layer CO2 data from a subset of GLOBALVIEW surface sites. Global annual net BS+BB+OC CO2 fluxes over 2004-2006 for GEOS-4 (GEOS-5) meteorology are -4.4±0.9 (-4.2±0.9), -3.9±0.9 (-4.5±0.9), and -5.2±0.9 (-4.9±0.9) Pg C yr-1 , respectively. The regional a posteriori fluxes are broadly consistent in the sign and magnitude of the TransCom-3 study for 1992-1996, but we find larger net sinks over northern and southern continents. We find large departures from our a priori over Europe during summer 2003, over temperate Eurasia during 2004, and over North America during 2005, reflecting an incomplete description of terrestrial carbon dynamics. We find GEOS-4 (GEOS-5) a posteriori CO2 concentrations reproduce the observed surface trend of 1.91-2.43 ppm yr-1, depending on latitude, within 0.15 ppm yr-1 (0.2 ppm yr-1) and the seasonal cycle within 0.2 ppm (0.2 ppm) at all latitudes. We find the a posteriori model reproduces the aircraft vertical profile measurements of CO2 over North America and Siberia generally within 1.5 ppm in the free and upper troposphere but can be biased by up to 4-5 ppm in the boundary layer at the start and end of the growing season. The model has a small negative bias in the free troposphere CO2 trend (1.95-2.19 ppm yr-1) compared to AIRS data which has a trend of 2.21-2.63 ppm yr-1 during 2004-2006, consistent with surface data. Model CO2 concentrations in the upper troposphere, evaluated using CONTRAIL (Comprehensive Observation Network for TRace gases by AIrLiner) aircraft measurements, reproduce the magnitude and phase of the seasonal cycle of CO2 in both hemispheres. We generally find that the GEOS meteorology reproduces much of the observed tropospheric CO2 variability, suggesting that these meteorological fields will help make significant progress in understanding carbon fluxes as more data become available.
A uniform geostationary visible calibration approach to achieve a climate quality dataset
NASA Astrophysics Data System (ADS)
Haney, C.; Doelling, D.; Bhatt, R.; Scarino, B. R.; Gopalan, A.
2013-12-01
The geostationary (GEO) weather satellite visible and IR image record has surpassed 30 years. They have been preserved in the ISCCP-B1U 3-hourly dataset and other archives such as McIDAS, EUMETSAT, and NOAA CLASS. Since they were designed to aid in weather forecasting, long-term calibration stability was not a high priority. All GEO imagers lack onboard visible calibration and suffer from optical degradation after they are launched. In order to piece together the 35+ GEO satellite record both in time and space, a uniform calibration approach is desired to remove individual GEO temporal trends, as well as GEO spectral band differences. Otherwise, any artificial discontinuities caused by sequential GEO satellite records or spurious temporal trends caused by optical degradation may be interpreted as a change in climate. The approach relies on multiple independent methods to reduce the overall uncertainty of the GEO calibration coefficients. Consistency among methods validates the approach. During the MODIS record (2000 to the present) the GEO satellites are inter-calibrated against MODIS using ray-matched or bore-sighted radiance pairs. The MODIS and the VIIRS follow on instruments are equipped with onboard calibration thereby providing a stable calibration reference. The GEO spectral band differences are accounted for using a Spectral Band Adjustment Factor (SBAF) based on hyper-spectral SCIAMACHY data. During the pre-MODIS era, invariant earth targets of deserts and deep convective clouds (DCC) are used. Since GEO imagers have maintained their imaging scan schedules, GEO desert and DCC bidirectional reflectance distribution functions (BRDF) can be constructed and validated during the MODIS era. The BRDF models can then be applied to historical GEO imagers. Consistency among desert and DCC GEO calibration gains validates the approach. This approach has been applied to the GEO record beginning in 1985 and the results will be presented at the meeting.
Dong, Feng; Wang, Xiaolin
2017-11-01
The present study was aimed to determine the effects of carboxymethyl cellulose (CMC)/garlic essential oil (GEO) composite coatings in improving the quality of strawberries stored at 20°C and 35-40% RH. To find the effects of CMC/GEO composite coatings, strawberries were coated with CMC, CMC+GEO (1%), CMC+GEO (2%), CMC+GEO (3%) and stored, while the uncoated strawberries were taken as control during storing. The effectiveness of CMC/GEO composite coatings was evaluated by measuring their weight loss, decay percentage, ascorbic acid, total phenols, anthocyanins, titratable acidity, total soluble solids and sensory evaluation. After 6days of storage, CMC+GEO (2%) composite coatings was found very effective in decreasing the senescence and maintaining the nutritional contents of strawberries. Results of this study confirm that CMC/GEO composite coatings can be used to improve the quality of strawberries. Copyright © 2017. Published by Elsevier B.V.
NASA Technical Reports Server (NTRS)
Stuhr, F. V.; Kent, S. S.; Galvez, J. L.; Luaces, B. G.; Pasero, G. R.; Urech, J. M.
1976-01-01
In support of the ongoing NASA-European Space Agency (ESA) effort to understand and control possible interference between missions, testing was conducted at the Madrid Deep Space Station from July 1975 to February 1976 to characterize the effect on Viking 1975 telecommunication link performance of Geodetic Earth-Orbiting Satellite (GEOS) downlink signals. The prime use of the data was to develop a capability to predict GEOS interference effects for evaluation of Viking 1975 mission impacts and possible temporary GEOS shutdown. Also, the data would serve as a basis for assessment of the GEOS impact on missions other than Viking as well as for more general interference applications. Performances of the reference receiver, telemetry, and planetary ranging were measured in the presence of various types of GEOS-related interference, including an unmodulated GEOS carrier and simulation of the actual spectrum by an ESA-supplied GEOS suitcase model.
Satellite Type Estination from Ground-based Photometric Observation
NASA Astrophysics Data System (ADS)
Endo, T.; Ono, H.; Suzuki, J.; Ando, T.; Takanezawa, T.
2016-09-01
The optical photometric observation is potentially a powerful tool for understanding of the Geostationary Earth Orbit (GEO) objects. At first, we measured in laboratory the surface reflectance of common satellite materials, for example, Multi-layer Insulation (MLI), mono-crystalline silicon cells, and Carbon Fiber Reinforced Plastic (CFRP). Next, we calculated visual magnitude of a satellite by simplified shape and albedo. In this calculation model, solar panels have dimensions of 2 by 8 meters, and the bus area is 2 meters squared with measured optical properties described above. Under these conditions, it clarified the brightness can change the range between 3 and 4 magnitudes in one night, but color index changes only from 1 to 2 magnitudes. Finally, we observed the color photometric data of several GEO satellites visible from Japan multiple times in August and September 2014. We obtained that light curves of GEO satellites recorded in the B and V bands (using Johnson filters) by a ground-base optical telescope. As a result, color index changed approximately from 0.5 to 1 magnitude in one night, and the order of magnitude was not changed in all cases. In this paper, we briefly discuss about satellite type estimation using the relation between brightness and color index obtained from the photometric observation.
Approaches to communication in response to geo-hydrological risk: POLARIS an Italian web initiative.
NASA Astrophysics Data System (ADS)
Salvati, Paola; Pernice, Umberto; Bianchi, Cinzia; Fiorucci, Federica; Marchesini, Ivan; Guzzetti, Fausto
2015-04-01
In the contemporary information and knowledge-based society, communication can foster effective responses to geo-hydrological risks, by increasing awareness on the causes and consequences of specific hazards, e.g., landslides, debris flows, and floods, and by fostering the capacity of individuals, groups, and organizations to prepare, manage and recover from geo-hydrological events. In this context, communication plays a vital role in all phases of the disaster cycle. Although in the last few years the scientific community has begun to disseminate information on geo-hydrological hazards and the associated risks through thematic websites, these remain mainly addressed to experts for specific technical purposes with contents and web interfaces hardly appreciated by a wider audience and rarely synchronised with social networks. To address the problem posed by the lack of communication on geo-hydrological hazards with potential human consequence in Italy, we designed the POLARIS Web site. The initiative we are conducting has the main object of contributing, in different ways and at different geographical scales, to raise awareness about landslides and floods, and their impact on the Italian society. The website is structured into six main sections (i.e. Reports, Are you ready, Events, Alert Zones, Focus and Blog) that provide different and complementary information including, respectively: periodical reports on landslide and flood risk to the population of Italy, suitable behaviors to adopt during damaging events, data and analyses on specific events, visual and detailed info on damaging events of the Italian Alert Zones defined by the Civil Protection Authority and blog-posts on landslide and flood events encouraging citizens' participation to crowd-sourcing information. Consultants experienced in project management, web-communication strategies on natural hazards, info-graphics, and user experience design were involved in the initiative to arrange and publish the information, considering usability and accessibility of the website, and key graphic aspects of web 2.0 information, making the web site communication more effective to users pertaining to diversified audiences. Specific icons are designed to describe the geo-hydrological events and maps to visualize their impact on the territory. The scientific and technical contents are edited using appropriate communication strategies which adopt a less technical and more widely comprehensible language, using intuitive and engaging web interfaces and linking messages to social media that encourage citizens' interactions. Monitoring the access of users to the website during more than a year after its publication, we noticed how the majority of the access corresponds to the occurrence of the worst geo-hydrological events and, in particular, when journalists or scientists promoted the website through television. Such a positive effect on the growth of users access suggested us to enhance our collaboration with scientific journalists by linking traditional (i.e. TV) and social media to further enlarge the awareness of website and to better explain users how to use the website information for increasing their resilience to geo-hydrological hazards.
NASA Technical Reports Server (NTRS)
Suarez, Max J. (Editor); daSilva, Arlindo; Dee, Dick; Bloom, Stephen; Bosilovich, Michael; Pawson, Steven; Schubert, Siegfried; Wu, Man-Li; Sienkiewicz, Meta; Stajner, Ivanka
2005-01-01
This document describes the structure and validation of a frozen version of the Goddard Earth Observing System Data Assimilation System (GEOS DAS): GEOS-4.0.3. Significant features of GEOS-4 include: version 3 of the Community Climate Model (CCM3) with the addition of a finite volume dynamical core; version two of the Community Land Model (CLM2); the Physical-space Statistical Analysis System (PSAS); and an interactive retrieval system (iRET) for assimilating TOVS radiance data. Upon completion of the GEOS-4 validation in December 2003, GEOS-4 became operational on 15 January 2004. Products from GEOS-4 have been used in supporting field campaigns and for reprocessing several years of data for CERES.
NASA Astrophysics Data System (ADS)
Dolecki, Leopold
2012-12-01
A systematic inventorying of natural objects and entire areas where objects of inanimate nature occur is being conducted in various countries to a different extent. In Poland, an important part is played by the Institute of Environmental Protection of PAS, the Polish Geological Institute, the University of Science and Technology (AGH) in Kraków, and numerous scientific institutions of higher education. During the UNESCO conference in 1997, an initiative was undertaken to create the so-called geoparks, i.e., documentation sites and nature reserves, associated in a regional network with a common theme. Such a network concentrates on the wealth of inanimate nature which is worth protecting due to its unique scientific, educational, historic and tourist value. This network works for the idea of sustained development and should have the support of the local authorities and community. The European Association for the Conservation of the Geological Heritage (ProGeo) is the organisation which integrates the research work concerning geoprotection. It undertook thenetwork of geosites, named Global Geosites. The GEOSITES programme is coordinated by the IUGS in cooperation with the ProGeo Association. The decision to add a given object to the world list is made during a UNESCO World Heritage Committee Session. In Poland, a preliminary list has been prepared featuring geosites nominated for the European list. A relatively small number of geosites represent the Lublin Region on that list. The article presents those sites and proposes that several more objects of inanimate nature situated in the region be included in that classification.
Rapid thermal cycling of new technology solar array blanket coupons
NASA Technical Reports Server (NTRS)
Scheiman, David A.; Smith, Bryan K.; Kurland, Richard M.; Mesch, Hans G.
1990-01-01
NASA Lewis Research Center is conducting thermal cycle testing of a new solar array blanket technologies. These technologies include test coupons for Space Station Freedom (SSF) and the advanced photovoltaic solar array (APSA). The objective of this testing is to demonstrate the durability or operational lifetime of the solar array interconnect design and blanket technology within a low earth orbit (LEO) or geosynchronous earth orbit (GEO) thermal cycling environment. Both the SSF and the APSA array survived all rapid thermal cycling with little or no degradation in peak performance. This testing includes an equivalent of 15 years in LEO for SSF test coupons and 30 years of GEO plus ten years of LEO for the APSA test coupon. It is concluded that both the parallel gap welding of the SSF interconnects and the soldering of the APSA interconnects are adequately designed to handle the thermal stresses of space environment temperature extremes.
GeoEye(TradeMark) Corporate Overview
NASA Technical Reports Server (NTRS)
Jones, Dennis
2007-01-01
This viewgraph presentation gives a corporate overview of GeoEye, the world's largest commercial remote sensing company. The contents include: 1) About GeoEye; 2) GeoEye Mission; 3) The Company; 4) Com,pany Summary; 5) U.S. Government Commitment; 6) GeoEye Constellation; 7) Other Imaging Resources; 8) OrbView-3 & OrbView-2; 9) OrbView-3 System Architecture; 10) OrbView-3; 11) OrbView-2; 12) IKONOS; 13) Largest Image Archive in the World; 14) GeoEye-1; 15) Best-In-Class Development Team; 16) Highest Performance Available in the Commercial Market; and 17) Key Themes
NASA Astrophysics Data System (ADS)
Feng, L.; Palmer, P. I.; Yang, Y.; Yantosca, R. M.; Kawa, S. R.; Paris, J.-D.; Matsueda, H.; Machida, T.
2011-03-01
We evaluate the GEOS-Chem atmospheric transport model (v8-02-01) of CO2 over 2003-2006, driven by GEOS-4 and GEOS-5 meteorology from the NASA Goddard Global Modeling and Assimilation Office, using surface, aircraft and space-borne concentration measurements of CO2. We use an established ensemble Kalman Filter to estimate a posteriori biospheric+biomass burning (BS + BB) and oceanic (OC) CO2 fluxes from 22 geographical regions, following the TransCom-3 protocol, using boundary layer CO2 data from a subset of GLOBALVIEW surface sites. Global annual net BS + BB + OC CO2 fluxes over 2004-2006 for GEOS-4 (GEOS-5) meteorology are -4.4 ± 0.9 (-4.2 ± 0.9), -3.9 ± 0.9 (-4.5 ± 0.9), and -5.2 ± 0.9 (-4.9 ± 0.9) PgC yr-1, respectively. After taking into account anthropogenic fossil fuel and bio-fuel emissions, the global annual net CO2 emissions for 2004-2006 are estimated to be 4.0 ± 0.9 (4.2 ± 0.9), 4.8 ± 0.9 (4.2 ± 0.9), and 3.8 ± 0.9 (4.1 ± 0.9) PgC yr-1, respectively. The estimated 3-yr total net emission for GEOS-4 (GEOS-5) meteorology is equal to 12.5 (12.4) PgC, agreeing with other recent top-down estimates (12-13 PgC). The regional a posteriori fluxes are broadly consistent in the sign and magnitude of the TransCom-3 study for 1992-1996, but we find larger net sinks over northern and southern continents. We find large departures from our a priori over Europe during summer 2003, over temperate Eurasia during 2004, and over North America during 2005, reflecting an incomplete description of terrestrial carbon dynamics. We find GEOS-4 (GEOS-5) a posteriori CO2 concentrations reproduce the observed surface trend of 1.91-2.43 ppm yr-1 (parts per million per year), depending on latitude, within 0.15 ppm yr-1 (0.2 ppm yr-1) and the seasonal cycle within 0.2 ppm (0.2 ppm) at all latitudes. We find the a posteriori model reproduces the aircraft vertical profile measurements of CO2 over North America and Siberia generally within 1.5 ppm in the free and upper troposphere but can be biased by up to 4-5 ppm in the boundary layer at the start and end of the growing season. The model has a small negative bias in the free troposphere CO2 trend (1.95-2.19 ppm yr-1) compared to AIRS data which has a trend of 2.21-2.63 ppm yr-1 during 2004-2006, consistent with surface data. Model CO2 concentrations in the upper troposphere, evaluated using CONTRAIL (Comprehensive Observation Network for TRace gases by AIrLiner) aircraft measurements, reproduce the magnitude and phase of the seasonal cycle of CO2 in both hemispheres. We generally find that the GEOS meteorology reproduces much of the observed tropospheric CO2 variability, suggesting that these meteorological fields will help make significant progress in understanding carbon fluxes as more data become available.
The GeoClaw software for depth-averaged flows with adaptive refinement
Berger, M.J.; George, D.L.; LeVeque, R.J.; Mandli, Kyle T.
2011-01-01
Many geophysical flow or wave propagation problems can be modeled with two-dimensional depth-averaged equations, of which the shallow water equations are the simplest example. We describe the GeoClaw software that has been designed to solve problems of this nature, consisting of open source Fortran programs together with Python tools for the user interface and flow visualization. This software uses high-resolution shock-capturing finite volume methods on logically rectangular grids, including latitude-longitude grids on the sphere. Dry states are handled automatically to model inundation. The code incorporates adaptive mesh refinement to allow the efficient solution of large-scale geophysical problems. Examples are given illustrating its use for modeling tsunamis and dam-break flooding problems. Documentation and download information is available at www.clawpack.org/geoclaw. ?? 2011.
GENERAL EARTHQUAKE-OBSERVATION SYSTEM (GEOS).
Borcherdt, R.D.; Fletcher, Joe B.; Jensen, E.G.; Maxwell, G.L.; VanSchaack, J.R.; Warrick, R.E.; Cranswick, E.; Johnston, M.J.S.; McClearn, R.
1985-01-01
Microprocessor technology has permitted the development of a General Earthquake-Observation System (GEOS) useful for most seismic applications. Central-processing-unit control via robust software of system functions that are isolated on hardware modules permits field adaptability of the system to a wide variety of active and passive seismic experiments and straightforward modification for incorporation of improvements in technology. Various laboratory tests and numerous deployments of a set of the systems in the field have confirmed design goals, including: wide linear dynamic range (16 bit/96 dB); broad bandwidth (36 hr to 600 Hz; greater than 36 hr available); selectable sensor-type (accelerometer, seismometer, dilatometer); selectable channels (1 to 6); selectable record mode (continuous, preset, trigger); large data capacity (1. 4 to 60 Mbytes); selectable time standard (WWVB, master, manual); automatic self-calibration; simple field operation; full capability to adapt system in the field to a wide variety of experiments; low power; portability; and modest costs. System design goals for a microcomputer-controlled system with modular software and hardware components as implemented on the GEOS are presented. The systems have been deployed for 15 experiments, including: studies of near-source strong motion; high-frequency microearthquakes; crustal structure; down-hole wave propagation; teleseismicity; and earth-tidal strains.
Hydrological Dynamics In High Mountain Catchment Areas of Central Norway
NASA Astrophysics Data System (ADS)
Löffler, Jörg; Rößler, Ole
Large-scaled landscape structure is regarded as a mosaic of ecotopes where process dynamics of water and energy fluxes are analysed due to its effects on ecosystem functioning. The investigations have been carried out in the continental most Vågå/Oppland high mountains in central Norway since 1994 (LÖFFLER &WUNDRAM 1999, 2000, 2001). Additionally, comparable investigations started in 2000 dealing with the oceanic high mountain landscapes on same latitudes (LÖFFLER et al. 2001). The theoretical and methodological framework of the project is given by the Landscape-Ecological Complex Analysis (MOSIMANN 1984, 1985) and its variations due to technical and principle methodical challenges in this high mountain landscape (KÖHLER et al. 1994, LÖFFLER 1998). The aim of the project is to characterize high mountain ecosystem structure, functioning and dynamics within small catchment areas, that are chosen in two different altitudinal belts each in the eastern continental and the western oceanic region of central Norway. In the frame of this research project hydrological and meteorological measurements on ground water, percolation and soil moisture dynamics as well as on evaporation, air humidity and air-, surface- and soil-temperatures have been conducted. On the basis of large-scaled landscape-ecological mappings (LÖFFLER 1997) one basic meteorological station and several major data logger run stations have been installed in representative sites of each two catchment areas in the low and mid alpine belts of the investigation regions ( JUNGet al. 1997, LÖFFLER &WUNDRAM 1997). Moreover, spatial differentiations of groundwater level, soil moisture and temperature profiles have been investigated by means of hand held measurements at different times of the day, during different climatic situations and different seasons. Daily and annual air-, surface- and soil-temperature dynamics are demonstrated by means of thermoisopleth-diagrams for different types of ecotopes of the different altitudinal belts. The local differences of temperature dynamics are illustrated in a map as an example of the low alpine altitudinal belt showing a 4-dimensional characterization (in space and time) of high mountain ecosystem functioning. Hydrological aspects derived from those results are presented showing the large- scaled hydrological dynamics of high mountain catchment basins in central Norway. The results of the process analysis of hydrological dynamics in the central Norwegian high mountains are discussed within the frame of investigations on altitudinal changes of mountain ecosystem structure and functioning (LÖFFLER &WUNDRAM [in print]). The poster illustrates the theoretical and methodological conception, methods and techniques, examples from complex data material as well as general outcomes of the project (RÖßLER [in prep.]. JUNG, G., J. LÖFFLER &D. WUNDRAM (1997): Untersuchungen zur Struktur, Funktion und Dynamik mittelnorwegischer Hochgebirgsökosysteme. Forschungsansatz. Oldenburger Geoökologisches Kolloquium 3: 4-36. Oldenburg. KÖHLER, B., J. LÖFFLER &D. WUNDRAM (1994): Probleme der kleinräumigen Geoökovarianz im mittelnorwegischen Gebirge. Norsk geogr. Tidsskr. 48: 99- 111. LÖFFLER, J. (1997): Großmaßstäbige geoökologische Kartierungen in den Höhenstufen des mittelnorwegischen Gebirges. NORDEN 12: 205-228. Bremen. LÖFFLER, J. (1998): Geoökologische Untersuchungen zur Struktur mittelnorwegischer Hochgebirgsökosysteme. Oldenburger Geoökologische Studien 1. Oldenburg. LÖFFLER, J., O.-D. FINCH, J. NAUJOK &R. PAPE (2001): Möglichkeiten der Integration zoologischer Aspekte in die landschaftsökologische Untersuchung von Hochgebirgen. Methodendiskussion am Beispiel ökologischer Prozesssysteme und Biozönosen. Naturschutz u. Landschaftsplanung 33 (11): 351-357. LÖFFLER, J. &D. WUNDRAM (1997): Klimatische Phänomene in mittelnorwegischen Hochgebirgslandschaften und ihre ökosystemare Bedeutung. Oldenburger Geoökologisches Kolloquium 3: 37-86. Oldenburg. LÖFFLER, J. &D. WUNDRAM (1999): Kleinräumige Klimavarianz im mittelnorwegischen Hochgebirgsraum Vågå/Oppland. NORDEN 13: 267 -276. Bremen. LÖFFLER, J. &D. WUNDRAM (2000) : Temperature Dynamics of Ecotopes in small Catchment Areas. In: C. BEIERKUHNLEIN et al. (Hrsg.): Zukunft mitteleuropäischer Kulturlandschaft. Analyse - Planung - Management. Tagungsband mit Kurzfassungen der Beiträge zur 1. Jahrestagung der IALE- Region Deutschland: 76, Nürtingen. LÖFFLER, J. &D. WUNDRAM (2001): Räumliche und zeitliche Differenzierung des Temperaturhaushalts von Hochgebirgsökosystemen. NORDEN 14: 85 -102. Bremen. LÖFFLER, J. &D. WUNDRAM (in print): Geoökologische Untersuchungen zur Prozessdynamik mittelnorwegischer Hochgebirgsökosysteme. Oldenburger Geoökologische Studien 2. Oldenburg. MOSIMANN, T. (1984): Landschaftsökologische Komplexanalyse. Wiesbaden. MOSIMANN, T. (1985): Untersuchungen zur Funktion subarktischer und alpiner Geoökosysteme (Finnmark [Norwegen] und Schweizer Alpen). Physiogeographica 7. Basel. RÖßLER, O. (in prep.): Modelling the Water Balance of Central Norwegian High Mountain Ecosystems. University of Oldenburg.
Promising Results from Three NASA SBIR Solar Array Technology Development Programs
NASA Technical Reports Server (NTRS)
Eskenazi, Mike; White, Steve; Spence, Brian; Douglas, Mark; Glick, Mike; Pavlick, Ariel; Murphy, David; O'Neill, Mark; McDanal, A. J.; Piszczor, Michael
2005-01-01
Results from three NASA SBIR solar array technology programs are presented. The programs discussed are: 1) Thin Film Photovoltaic UltraFlex Solar Array; 2) Low Cost/Mass Electrostatically Clean Solar Array (ESCA); and 3) Stretched Lens Array SquareRigger (SLASR). The purpose of the Thin Film UltraFlex (TFUF) Program is to mature and validate the use of advanced flexible thin film photovoltaics blankets as the electrical subsystem element within an UltraFlex solar array structural system. In this program operational prototype flexible array segments, using United Solar amorphous silicon cells, are being manufactured and tested for the flight qualified UltraFlex structure. In addition, large size (e.g. 10 kW GEO) TFUF wing systems are being designed and analyzed. Thermal cycle and electrical test and analysis results from the TFUF program are presented. The purpose of the second program entitled, Low Cost/Mass Electrostatically Clean Solar Array (ESCA) System, is to develop an Electrostatically Clean Solar Array meeting NASA s design requirements and ready this technology for commercialization and use on the NASA MMS and GED missions. The ESCA designs developed use flight proven materials and processes to create a ESCA system that yields low cost, low mass, high reliability, high power density, and is adaptable to any cell type and coverglass thickness. All program objectives, which included developing specifications, creating ESCA concepts, concept analysis and trade studies, producing detailed designs of the most promising ESCA treatments, manufacturing ESCA demonstration panels, and LEO (2,000 cycles) and GEO (1,350 cycles) thermal cycling testing of the down-selected designs were successfully achieved. The purpose of the third program entitled, "High Power Platform for the Stretched Lens Array," is to develop an extremely lightweight, high efficiency, high power, high voltage, and low stowed volume solar array suitable for very high power (multi-kW to MW) applications. These objectives are achieved by combining two cutting edge technologies, the SquareRigger solar array structure and the Stretched Lens Array (SLA). The SLA SquareRigger solar array is termed SLASR. All program objectives, which included developing specifications, creating preliminary designs for a near-term SLASR, detailed structural, mass, power, and sizing analyses, fabrication and power testing of a functional flight-like SLASR solar blanket, were successfully achieved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Murphy, Neil R.; Grant, J. T.; Sun, L.
2014-03-18
Germanium oxide (GeO x) films were grown on (1 0 0) Si substrates by reactive Direct-Current (DC) magnetron sputter-deposition using an elemental Ge target. The effects of oxygen gas fraction, Г = O 2/(Ar + O 2), on the deposition rate, structure, chemical composition and optical properties of GeOx films have been investigated. The chemistry of the films exhibits an evolution from pure Ge to mixed Ge + GeO + GeO 2 and then finally to GeO 2 upon increasing Г from 0.00 to 1.00. Grazing incidence X-ray analysis indicates that the GeO x films grown were amorphous. The opticalmore » properties probed by spectroscopic ellipsometry indicate that the effect of Г is significant on the optical constants of the GeO x films. The measured index of refraction (n) at a wavelength (λ) of 550 nm is 4.67 for films grown without any oxygen, indicating behavior characteristic of semiconducting Ge. The transition from germanium to mixed Ge + GeO + GeO 2 composition is associated with a characteristic decrease in n (λ = 550 nm) to 2.62 and occurs at Г = 0.25. Finally n drops to 1.60 for Г = 0.50–1.00, where the films become GeO 2. A detailed correlation between Г, n, k and stoichiometry in DC sputtered GeO x films is presented and discussed.« less
A comprehensive assessment of collision likelihood in Geosynchronous Earth Orbit
NASA Astrophysics Data System (ADS)
Oltrogge, D. L.; Alfano, S.; Law, C.; Cacioni, A.; Kelso, T. S.
2018-06-01
Knowing the likelihood of collision for satellites operating in Geosynchronous Earth Orbit (GEO) is of extreme importance and interest to the global community and the operators of GEO spacecraft. Yet for all of its importance, a comprehensive assessment of GEO collision likelihood is difficult to do and has never been done. In this paper, we employ six independent and diverse assessment methods to estimate GEO collision likelihood. Taken in aggregate, this comprehensive assessment offer new insights into GEO collision likelihood that are within a factor of 3.5 of each other. These results are then compared to four collision and seven encounter rate estimates previously published. Collectively, these new findings indicate that collision likelihood in GEO is as much as four orders of magnitude higher than previously published by other researchers. Results indicate that a collision is likely to occur every 4 years for one satellite out of the entire GEO active satellite population against a 1 cm RSO catalogue, and every 50 years against a 20 cm RSO catalogue. Further, previous assertions that collision relative velocities are low (i.e., <1 km/s) in GEO are disproven, with some GEO relative velocities as high as 4 km/s identified. These new findings indicate that unless operators successfully mitigate this collision risk, the GEO orbital arc is and will remain at high risk of collision, with the potential for serious follow-on collision threats from post-collision debris when a substantial GEO collision occurs.
LEO to GEO (and Beyond) Transfers Using High Power Solar Electric Propulsion (HP-SEP)
NASA Technical Reports Server (NTRS)
Loghry, Christopher S.; Oleson, Steven R.; Woytach, Jeffrey M.; Martini, Michael C.; Smith, David A.; Fittje, James E.; Gyekenyesi, John Z.; Colozza, Anthony J.; Fincannon, James; Bogner, Aimee;
2017-01-01
Rideshare, or Multi-Payload launch configurations, are becoming more and more commonplace but access to space is only one part of the overall mission needs. The ability for payloads to achieve their target orbits or destinations can still be difficult and potentially not feasible with on-board propulsion limitations. The High Power Solar Electric Propulsion (HP-SEP) Orbital Maneuvering Vehicle (OMV) provides transfer capabilities for both large and small payload in excess of what is possible with chemical propulsion. Leveraging existing secondary payload adapter technology like the ESPA provides a platform to support Multi-Payload launch and missions. When coupled with HP-SEP, meaning greater than 30 kW system power, very large delta-V maneuvers can be accomplished. The HP-SEP OMV concept is designed to perform a Low Earth Orbit to Geosynchronous Orbit (LEO-GEO) transfer of up to six payloads each with 300kg mass. The OMV has enough capability to perform this 6 kms maneuver and have residual capacity to extend an additional transfer from GEO to Lunar orbit. This high deltaV capability is achieved using state of the art 12.5kW Hall Effect Thrusters (HET) coupled with high power roll up solar arrays. The HP-SEP OMV also provides a demonstration platform for other SEP technologies such as advanced Power Processing Units (PPU), Xenon Feed Systems (XFS), and other HET technologies. The HP-SEP OMV platform can be leveraged for other missions as well such as interplanetary science missions and applications for resilient space architectures.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Maccarthy, Jonathan K.
2016-07-28
PyGeoTess is a Python interface module to the GeoTess gridding and earth model library from Sandia National Laboratories. It provides simplified access to a subset of the GeoTess C++ library, and takes advantage of Python's interactive interpreter and inline documentation system.
SOIL Geo-Wiki: A tool for improving soil information
NASA Astrophysics Data System (ADS)
Skalský, Rastislav; Balkovic, Juraj; Fritz, Steffen; See, Linda; van der Velde, Marijn; Obersteiner, Michael
2014-05-01
Crowdsourcing is increasingly being used as a way of collecting data for scientific research, e.g. species identification, classification of galaxies and unravelling of protein structures. The WorldSoilProfiles.org database at ISRIC is a global collection of soil profiles, which have been 'crowdsourced' from experts. This system, however, requires contributors to have a priori knowledge about soils. Yet many soil parameters can be observed in the field without specific knowledge or equipment such as stone content, soil depth or color. By crowdsourcing this information over thousands of locations, the uncertainty in current soil datasets could be radically reduced, particularly in areas currently without information or where multiple interpretations are possible from different existing soil maps. Improved information on soils could benefit many research fields and applications. Better soil data could enhance assessments of soil ecosystem services (e.g. soil carbon storage) and facilitate improved process-based ecosystem modeling from local to global scales. Geo-Wiki is a crowdsourcing tool that was developed at IIASA for land cover validation using satellite imagery. Several branches are now available focused on specific aspects of land cover validation, e.g. validating cropland extent or urbanized areas. Geo-Wiki Pictures is a smart phone application for collecting land cover related information on the ground. The extension of Geo-Wiki to a mobile environment provides a tool for experts in land cover validation but is also a way of reaching the general public in the validation of land cover. Here we propose a Soil Geo-Wiki tool that builds on the existing functionality of the Geo-Wiki application, which will be largely designed for the collection and sharing of soil information. Two distinct applications are envisaged: an expert-oriented application mainly for scientific purposes, which will use soil science related language (e.g. WRB or any other global reference soil classification system) and allow experts to upload and share scientifically rigorous soil data; and an application oriented towards the general public, which will be more focused on describing well observed, individual soil properties using simplified classification keys. The latter application will avoid the use of soil science related terminology and focus on the most useful soil parameters such as soil surface features, stone content, soil texture, soil plasticity, calcium carbonate presence, soil color, soil pH, soil repellency, and soil depth. Collection of soil and landscape pictures will also be supported in Soil Geo-Wiki to allow for comprehensive data collection while simultaneously allowing for quality checking by experts.
Heimdall System for MSSS Sensor Tasking
NASA Astrophysics Data System (ADS)
Herz, A.; Jones, B.; Herz, E.; George, D.; Axelrad, P.; Gehly, S.
In Norse Mythology, Heimdall uses his foreknowledge and keen eyesight to keep watch for disaster from his home near the Rainbow Bridge. Orbit Logic and the Colorado Center for Astrodynamics Research (CCAR) at the University of Colorado (CU) have developed the Heimdall System to schedule observations of known and uncharacterized objects and search for new objects from the Maui Space Surveillance Site. Heimdall addresses the current need for automated and optimized SSA sensor tasking driven by factors associated with improved space object catalog maintenance. Orbit Logic and CU developed an initial baseline prototype SSA sensor tasking capability for select sensors at the Maui Space Surveillance Site (MSSS) using STK and STK Scheduler, and then added a new Track Prioritization Component for FiSST-inspired computations for predicted Information Gain and Probability of Detection, and a new SSA-specific Figure-of-Merit (FOM) for optimized SSA sensor tasking. While the baseline prototype addresses automation and some of the multi-sensor tasking optimization, the SSA-improved prototype addresses all of the key elements required for improved tasking leading to enhanced object catalog maintenance. The Heimdall proof-of-concept was demonstrated for MSSS SSA sensor tasking for a 24 hour period to attempt observations of all operational satellites in the unclassified NORAD catalog, observe a small set of high priority GEO targets every 30 minutes, make a sky survey of the GEO belt region accessible to MSSS sensors, and observe particular GEO regions that have a high probability of finding new objects with any excess sensor time. This Heimdall prototype software paves the way for further R&D that will integrate this technology into the MSSS systems for operational scheduling, improve the software's scalability, and further tune and enhance schedule optimization. The Heimdall software for SSA sensor tasking provides greatly improved performance over manual tasking, improved coordinated sensor usage, and tasking schedules driven by catalog improvement goals (reduced overall covariance, etc.). The improved performance also enables more responsive sensor tasking to address external events, newly detected objects, newly detected object activity, and sensor anomalies. Instead of having to wait until the next day's scheduling phase, events can be addressed with new tasking schedules immediately (within seconds or minutes). Perhaps the most important benefit is improved SSA based on an overall improvement to the quality of the space catalog. By driving sensor tasking and scheduling based on predicted Information Gain and other relevant factors, better decisions are made in the application of available sensor resources, leading to an improved catalog and better information about the objects of most interest. The Heimdall software solution provides a configurable, automated system to improve sensor tasking efficiency and responsiveness for SSA applications. The FISST algorithms for Track Prioritization, SSA specific task and resource attributes, Scheduler algorithms, and configurable SSA-specific Figure-of-Merit together provide optimized and tunable scheduling for the Maui Space Surveillance Site and possibly other sites and organizations across the U.S. military and for allies around the world.
Effective Detection of Low-luminosity GEO Objects Using Population and Motion Predictions
2012-01-01
more assumptions made on the time, and then tracks all the points where most fragments will be in geocentric equatorial inertial coordinates over time...population. A couple of candidate points in geocentric equatorial inertial coordinates can be selected with consideration that bright stars will not be... geocentric equatorial inertial coordinates. Third, motion of fragments passing through the specified single point in geocentric equatorial
ERIC Educational Resources Information Center
Davis, Michael
2014-01-01
The purpose of this article is to provide a summary of what is known about teaching ethics in engineering, science, and related disciplines. Such a summary should provide a useful starting point for preparation of a detailed curriculum for teaching the ethics of geo-coded information systems broadly understood ("GIS ethics" for short).…
Dumitru Salajanu; Dennis Jacobs
2010-01-01
Forest inventory and analysis data are used to monitor the presence and extent of certain non-native invasive species. Effective control of its spread requires quality spatial distribution information. There is no clear consensus why some ecosystems are more favorable to non-native species. The objective of this study is to evaluate the reelative contribution of geo-...
Satellite Photometric Error Determination
2015-10-18
the GEO Color Photometry Catalog (GCPC) that tried to remedy some of the problems listed above for geostationary satellites. In particular, we... Geostationary objects over the continental US Develop new feature extraction methods such as albedo-area measurements Understanding of seasonal...Fig. 4 and Fig. 5, there are examples of color photometry signatures for a 3-axis stabilized geostationary satellite. The data were taken with a
NASA Technical Reports Server (NTRS)
Abercromby, Kira J.; Rapp, Jason; Bedard, Donald; Seitzer, Patrick; Cardona, Tommaso; Cowardin, Heather; Barker, Ed; Lederer, Susan
2013-01-01
Constrained Linear Least Squares model is generally more accurate than the "human-in-the-loop". However, "human-in-the-loop" can remove materials that make no sense. The speed of the model in determining a "first cut" at the material ID makes it a viable option for spectral unmixing of debris objects.
Magnetospheric electric fields and auroral oval
NASA Technical Reports Server (NTRS)
Laakso, Harri; Pedersen, Arne; Craven, John D.; Frank, L. A.
1992-01-01
DC electric field variations in a synchronous orbit (GEOS 2) during four substorms in the time sector 19 to 01 LT were investigated. Simultaneously, the imaging photometer on board DE 1 provided auroral images that are also utilized. Substorm onset is defined here as a sudden appearance of large electric fields. During the growth phase, the orientation of the electric field begins to oscillate some 30 min prior to onset. About 10 min before the onset GEOS 2 starts moving into a more tenuous plasma, probably due to a thinning of the current sheet. The onset is followed by a period of 10 to 15 min during which large electric fields occur. This interval can be divided into two intervals. During the first interval, which lasts 4 to 8 min, very large fields of 8 to 20 mV/m are observed, while the second interval contains relatively large fields (2 to 5 mV/m). A few min after the onset, the spacecraft returns to a plasma region of higher electron fluxes which are usually larger than before substorm. Some 30 min after onset, enhanced activity, lasting about 10 min, appears in the electric field. One of the events selected offers a good opportunity to study the formation and development of the Westward Traveling Surge (WST). During the traversal of the leading edge of the WTS (approximately 8 min) a stable wave mode at 5.7 mHz is detected.
Worldwide biogenic soil NOx emission estimates from OMI NO2 observations and the GEOS-Chem model
NASA Astrophysics Data System (ADS)
Vinken, Geert; Boersma, Folkert; Maasakkers, Bram; Martin, Randall
2014-05-01
Bacteria in soils are an important source of biogenic nitrogen oxides (NOx = NO + NO2), which are important precursors for ozone (O3) formation. Furthermore NOx emissions contribute to increased nitrogen deposition and particulate matter formation. Bottom-up estimates of global soil NOx emissions range from 4 to 27 Tg N / yr, reflecting our incomplete knowledge of emission factors and processes driving these emissions. In this study we used, for the first time, OMI NO2 columns on all continents to reduce the uncertainty in soil NOx emissions. Regions and months dominated by soil NOx emissions were identified using a filtering scheme in the GEOS-Chem chemistry transport model. Consequently, we compared OMI observed NO2 observed columns to GEOS-Chem simulated columns and provide constraints for these months in 11 regions. This allows us to provide a top-down emission inventory for 2005 for soil NOx emissions from all continents. Our total global soil NOx emission inventory amounts to 10 Tg N / yr. Our estimate is 4% higher than the GEOS-Chem a priori (Hudman et al., 2012), but substantial regional differences exist (e.g. +20% for Sahel and India; and -40% for mid-USA). We furthermore observed a stronger seasonal cycle in the Sahel region, indicating directions for possible future improvements to the parameterization currently used in GEOS-Chem. We validated NO2 concentrations simulated with this new top-down inventory against surface NO2 measurements from monitoring stations in Africa, the USA and Europe. On the whole, we conclude that simulations with our new top-down inventory better agree with measurements. Our work shows that satellite retrieved NO2 columns can improve estimates of soil NOx emissions over sparsely monitored remote rural areas. We show that the range in previous estimates of soil NOx emissions is too large, and global emissions are most likely around 10 Tg N/yr, in agreement with the most recent parameterizations.
Töpel, Mats; Zizka, Alexander; Calió, Maria Fernanda; Scharn, Ruud; Silvestro, Daniele; Antonelli, Alexandre
2017-03-01
Understanding the patterns and processes underlying the uneven distribution of biodiversity across space constitutes a major scientific challenge in systematic biology and biogeography, which largely relies on effectively mapping and making sense of rapidly increasing species occurrence data. There is thus an urgent need for making the process of coding species into spatial units faster, automated, transparent, and reproducible. Here we present SpeciesGeoCoder, an open-source software package written in Python and R, that allows for easy coding of species into user-defined operational units. These units may be of any size and be purely spatial (i.e., polygons) such as countries and states, conservation areas, biomes, islands, biodiversity hotspots, and areas of endemism, but may also include elevation ranges. This flexibility allows scoring species into complex categories, such as those encountered in topographically and ecologically heterogeneous landscapes. In addition, SpeciesGeoCoder can be used to facilitate sorting and cleaning of occurrence data obtained from online databases, and for testing the impact of incorrect identification of specimens on the spatial coding of species. The various outputs of SpeciesGeoCoder include quantitative biodiversity statistics, global and local distribution maps, and files that can be used directly in many phylogeny-based applications for ancestral range reconstruction, investigations of biome evolution, and other comparative methods. Our simulations indicate that even datasets containing hundreds of millions of records can be analyzed in relatively short time using a standard computer. We exemplify the use of SpeciesGeoCoder by inferring the historical dispersal of birds across the Isthmus of Panama, showing that lowland species crossed the Isthmus about twice as frequently as montane species with a marked increase in the number of dispersals during the last 10 million years. [ancestral area reconstruction; biodiversity patterns; ecology; evolution; point in polygon; species distribution data.]. © The Author(s) 2016. Published by Oxford University Press, on behalf of the Society of Systematic Biologists.
2012-01-01
Background Monoterpenes present a large and versatile group of unsaturated hydrocarbons of plant origin with widespread use in the fragrance as well as food industry. The anaerobic β-myrcene degradation pathway in Castellaniella defragrans strain 65Phen differs from well known aerobic, monooxygenase-containing pathways. The initial enzyme linalool dehydratase-isomerase ldi/LDI catalyzes the hydration of β-myrcene to (S)-(+)-linalool and its isomerization to geraniol. A high-affinity geraniol dehydrogenase geoA/GeDH and a geranial dehydrogenase geoB/GaDH contribute to the formation of geranic acid. A genetic system was for the first time applied for the betaproteobacterium to prove in vivo the relevance of the linalool dehydratase-isomerase and the geraniol dehydrogenase. In-frame deletion cassettes were introduced by conjugation and two homologous recombination events. Results Polar effects were absent in the in-frame deletion mutants C. defragrans Δldi and C. defragrans ΔgeoA. The physiological characterization of the strains demonstrated a requirement of the linalool dehydratase-isomerase for growth on acyclic monoterpenes, but not on cyclic monoterpenes. The deletion of geoA resulted in a phenotype with hampered growth rate on monoterpenes as sole carbon and energy source as well as reduced biomass yields. Enzyme assays revealed the presence of a second geraniol dehydrogenase. The deletion mutants were in trans complemented with the broad-host range expression vector pBBR1MCS-4ldi and pBBR1MCS-2geoA, restoring in both cases the wild type phenotype. Conclusions In-frame deletion mutants of genes in the anaerobic β-myrcene degradation revealed novel insights in the in vivo function. The deletion of a high-affinity geraniol dehydrogenase hampered, but did not preclude growth on monoterpenes. A second geraniol dehydrogenase activity was present that contributes to the β-myrcene degradation pathway. Growth on cyclic monoterpenes independent of the initial enzyme LDI suggests the presence of a second enzyme system activating unsaturated hydrocarbons. PMID:22947208
NASA Technical Reports Server (NTRS)
Kim, Min-Jeong; Jin, Jianjun; McCarty, Will; El Akkraoui, Amal; Todling, Ricardo; Gelaro, Ron
2018-01-01
Many numerical weather prediction (NWP) centers assimilate radiances affected by clouds and precipitation from microwave sensors, with the expectation that these data can provide critical constraints on meteorological parameters in dynamically sensitive regions to make significant impacts on forecast accuracy for precipitation. The Global Modeling and Assimilation Office (GMAO) at NASA Goddard Space Flight Center assimilates all-sky microwave radiance data from various microwave sensors such as all-sky GPM Microwave Imager (GMI) radiance in the Goddard Earth Observing System (GEOS) atmospheric data assimilation system (ADAS), which includes the GEOS atmospheric model, the Gridpoint Statistical Interpolation (GSI) atmospheric analysis system, and the Goddard Aerosol Assimilation System (GAAS). So far, most of NWP centers apply same large data thinning distances, that are used in clear-sky radiance data to avoid correlated observation errors, to all-sky microwave radiance data. For example, NASA GMAO is applying 145 km thinning distances for most of satellite radiance data including microwave radiance data in which all-sky approach is implemented. Even with these coarse observation data usage in all-sky assimilation approach, noticeable positive impacts from all-sky microwave data on hurricane track forecasts were identified in GEOS-5 system. The motivation of this study is based on the dynamic thinning distance method developed in our all-sky framework to use of denser data in cloudy and precipitating regions due to relatively small spatial correlations of observation errors. To investigate the benefits of all-sky microwave radiance on hurricane forecasts, several hurricane cases selected between 2016-2017 are examined. The dynamic thinning distance method is utilized in our all-sky approach to understand the sources and mechanisms to explain the benefits of all-sky microwave radiance data from various microwave radiance sensors like Advanced Microwave Sounder Unit (AMSU-A), Microwave Humidity Sounder (MHS), and GMI on GEOS-5 analyses and forecasts of various hurricanes.
NASA Astrophysics Data System (ADS)
Wang, Xiaolei; Xiang, Jinjuan; Wang, Shengkai; Wang, Wenwu; Zhao, Chao; Ye, Tianchun; Xiong, Yuhua; Zhang, Jing
2016-06-01
Remote Coulomb scattering (RCS) on electron mobility degradation is investigated experimentally in Ge-based metal-oxide-semiconductor field-effect-transistors (MOSFETs) with GeO x /Al2O3 gate stacks. It is found that the mobility increases with greater GeO x thickness (7.8-20.8 Å). The physical origin of this mobility dependence on GeO x thickness is explored. The following factors are excluded: Coulomb scattering due to interfacial traps at GeO x /Ge, phonon scattering, and surface roughness scattering. Therefore, the RCS from charges in gate stacks is studied. The charge distributions in GeO x /Al2O3 gate stacks are evaluated experimentally. The bulk charges in Al2O3 and GeO x are found to be negligible. The density of the interfacial charge is +3.2 × 1012 cm-2 at the GeO x /Ge interface and -2.3 × 1012 cm-2 at the Al2O3/GeO x interface. The electric dipole at the Al2O3/GeO x interface is found to be +0.15 V, which corresponds to an areal charge density of 1.9 × 1013 cm-2. The origin of this mobility dependence on GeO x thickness is attributed to the RCS due to the electric dipole at the Al2O3/GeO x interface. This remote dipole scattering is found to play a significant role in mobility degradation. The discovery of this new scattering mechanism indicates that the engineering of the Al2O3/GeO x interface is key for mobility enhancement and device performance improvement. These results are helpful for understanding and engineering Ge mobility enhancement.
Gundersen, Gregory W; Jones, Matthew R; Rouillard, Andrew D; Kou, Yan; Monteiro, Caroline D; Feldmann, Axel S; Hu, Kevin S; Ma'ayan, Avi
2015-09-15
Identification of differentially expressed genes is an important step in extracting knowledge from gene expression profiling studies. The raw expression data from microarray and other high-throughput technologies is deposited into the Gene Expression Omnibus (GEO) and served as Simple Omnibus Format in Text (SOFT) files. However, to extract and analyze differentially expressed genes from GEO requires significant computational skills. Here we introduce GEO2Enrichr, a browser extension for extracting differentially expressed gene sets from GEO and analyzing those sets with Enrichr, an independent gene set enrichment analysis tool containing over 70 000 annotated gene sets organized into 75 gene-set libraries. GEO2Enrichr adds JavaScript code to GEO web-pages; this code scrapes user selected accession numbers and metadata, and then, with one click, users can submit this information to a web-server application that downloads the SOFT files, parses, cleans and normalizes the data, identifies the differentially expressed genes, and then pipes the resulting gene lists to Enrichr for downstream functional analysis. GEO2Enrichr opens a new avenue for adding functionality to major bioinformatics resources such GEO by integrating tools and resources without the need for a plug-in architecture. Importantly, GEO2Enrichr helps researchers to quickly explore hypotheses with little technical overhead, lowering the barrier of entry for biologists by automating data processing steps needed for knowledge extraction from the major repository GEO. GEO2Enrichr is an open source tool, freely available for installation as browser extensions at the Chrome Web Store and FireFox Add-ons. Documentation and a browser independent web application can be found at http://amp.pharm.mssm.edu/g2e/. avi.maayan@mssm.edu. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
CER_SRBAVG_Aqua-FM3-MODIS_Edition2A
Atmospheric Science Data Center
2014-07-24
... Readme Files: Readme R4-671 UNIX C shell scripts for extracting regional CERES geo and non-geo fluxes from ... Software Files : Read Package (C) UNIX C shell scripts for extracting regional CERES geo and non-geo fluxes from ...
Differential Epidemiology: IQ, Neuroticism, and Chronic Disease by the 50 U.S. States
ERIC Educational Resources Information Center
Pesta, Bryan J.; Bertsch, Sharon; McDaniel, Michael A.; Mahoney, Christine B.; Poznanski, Peter J.
2012-01-01
Current research shows that geo-political units (e.g., the 50 U.S. states) vary meaningfully on psychological dimensions like intelligence (IQ) and neuroticism (N). A new scientific discipline has also emerged, differential epidemiology, focused on how psychological variables affect health. We integrate these areas by reporting large correlations…
Map of critical raw material deposits in Europe
NASA Astrophysics Data System (ADS)
Guillaume, Bertrand
2016-04-01
Map of critical raw material deposits in Europe Guillaume BERTRAND1, Daniel CASSARD1, Nikolaos ARVANITIDIS2, Gerry STANLEY3 and the EuroGeoSurvey Mineral Resources Expert Group4. 1 - Bureau de Recherches Géologiques et Minières (BRGM), Georesources Divison, 3 avenue Claude Guillemin, 45060 Orléans cedex 2, FRANCE. 2 - Sveriges Geologiska Undersökning (SGU), Box 670, SE-751 28, Uppsala, SWEDEN 3 - Geological Survey of Ireland (GSI), Beggars Bush, Haddington Road, Dublin D04 K7X4, IRELAND 4 - EuroGeoSurveys, Rue Joseph II 36-38, 1000 Brussels, BELGIUM The Critical Raw Material (CRM) Deposit Map of Europe, prepared by EuroGeoSurvey's Mineral Resources Expert Group (MREG), shows European mineral deposits from the ProMine Mineral Deposit database containing critical commodities, according to the 2014 list of critical raw materials of the European Commission. EuroGeoSurveys (EGS), The Geological Surveys of Europe, is a not-for-profit organization representing 37 National Geological Surveys and some regional Geological Surveys in Europe. It provides the European Institutions with expert, independent, balanced and practical pan-European advice and information as an aid to problem-solving, policy development, regulatory and programme formulation in areas such as natural resources, energy and geo-hazards. The EGS MREG is actively involved in contributing to policy and strategy-making processes aimed at identifying, characterizing and safeguarding resource potential, especially for critical raw materials through data provision, research, technological development and innovation. The European Union aspires to reducing the import dependency of raw materials, especially CRM, that are essential to Europe's industries. In this respect, mineral resource information, data sharing and networking by European Geological Surveys is crucial. The Strategic Implementation Plan of the European Innovation Partnership on Raw Materials highlights the need for establishing and maintaining a common interoperable EU Geological Knowledge Base. Such a Knowledge Base will support exploration for indigenous mineral resources and strengthen policy and decision making. In 2010, the European Commission identified 14 non energy non-agricultural raw materials as being critical. Criticality is based on both the scarcity of supply and the importance to European industry. This list was updated in 2014 to include 7 new commodities with one being dropped from the original list. The list now comprises: antimony, beryllium, borates, chromium, cobalt, coking coal, fluorspar, gallium, germanium, graphite, indium, magnesite, magnesium, niobium, phosphate rock, platinum group metals, light and heavy rare earth elements (separately), silicon metal and tungsten. ProMine was a European Union (EU) co-funded project, which had as its main objective the stimulation of the extractive industry to deliver new products to manufacturing industry. A major deliverable of the project was the ProMine Mineral Deposit (MD) database that contains information related to almost 13,000 mineral deposits in Europe. In order to extract data to be displayed on the CRM map of Europe, the ProMine MD database was queried for all commodities on the EC CRM list which were in the medium to super-large deposit size. Following this, the dataset was circulated to MREG in order to verify, validate and update the list.
NASA Astrophysics Data System (ADS)
Hao, Ming; Rohrdantz, Christian; Janetzko, Halldór; Keim, Daniel; Dayal, Umeshwar; Haug, Lars-Erik; Hsu, Mei-Chun
2012-01-01
Twitter currently receives over 190 million tweets (small text-based Web posts) and manufacturing companies receive over 10 thousand web product surveys a day, in which people share their thoughts regarding a wide range of products and their features. A large number of tweets and customer surveys include opinions about products and services. However, with Twitter being a relatively new phenomenon, these tweets are underutilized as a source for determining customer sentiments. To explore high-volume customer feedback streams, we integrate three time series-based visual analysis techniques: (1) feature-based sentiment analysis that extracts, measures, and maps customer feedback; (2) a novel idea of term associations that identify attributes, verbs, and adjectives frequently occurring together; and (3) new pixel cell-based sentiment calendars, geo-temporal map visualizations and self-organizing maps to identify co-occurring and influential opinions. We have combined these techniques into a well-fitted solution for an effective analysis of large customer feedback streams such as for movie reviews (e.g., Kung-Fu Panda) or web surveys (buyers).
NASA Astrophysics Data System (ADS)
Isikdag, U.; Pilouk, M.
2016-06-01
More and more devices are starting to be connected to the Internet every day. Internet-of-Things (IoT) is known as an architecture where online devices have the ability to communicate and interact with each other in real-time. On the other hand, with the development of IoT related technologies information about devices (i.e. Things) can be acquired in real-time by the humans. The implementation of IoT related technologies requires new approaches to be investigated for novel system architectures. These architectures need to have 3 main abilities. The first one is the ability is to store and query information coming from millions of devices in real-time. The second one is the ability to interact with large number of devices seamlessly regardless of their hardware and their software platforms. The final one is the ability to visualise and present information coming from millions of sensors in real time. The paper provides an architectural approach and implementation tests for storage, exposition and presentation of large amounts of real-time geo-information coming from multiple IoT nodes (and sensors).
Jensenius, Mogens; Han, Pauline V.; Schlagenhauf, Patricia; Schwartz, Eli; Parola, Philippe; Castelli, Francesco; von Sonnenburg, Frank; Loutan, Louis; Leder, Karin; Freedman, David O.
2013-01-01
We performed a descriptive analysis of acute and potentially life-threatening tropical diseases among 82,825 ill western travelers reported to GeoSentinel from June of 1996 to August of 2011. We identified 3,655 patients (4.4%) with a total of 3,666 diagnoses representing 13 diseases, including falciparum malaria (76.9%), enteric fever (18.1%), and leptospirosis (2.4%). Ninety-one percent of the patients had fever; the median time from travel to presentation was 16 days. Thirteen (0.4%) patients died: 10 with falciparum malaria, 2 with melioidosis, and 1 with severe dengue. Falciparum malaria was mainly acquired in West Africa, and enteric fever was largely contracted on the Indian subcontinent; leptospirosis, scrub typhus, and murine typhus were principally acquired in Southeast Asia. Western physicians seeing febrile and recently returned travelers from the tropics need to consider a wide profile of potentially life-threatening tropical illnesses, with a specific focus on the most likely diseases described in our large case series. PMID:23324216
Camera Control and Geo-Registration for Video Sensor Networks
NASA Astrophysics Data System (ADS)
Davis, James W.
With the use of large video networks, there is a need to coordinate and interpret the video imagery for decision support systems with the goal of reducing the cognitive and perceptual overload of human operators. We present computer vision strategies that enable efficient control and management of cameras to effectively monitor wide-coverage areas, and examine the framework within an actual multi-camera outdoor urban video surveillance network. First, we construct a robust and precise camera control model for commercial pan-tilt-zoom (PTZ) video cameras. In addition to providing a complete functional control mapping for PTZ repositioning, the model can be used to generate wide-view spherical panoramic viewspaces for the cameras. Using the individual camera control models, we next individually map the spherical panoramic viewspace of each camera to a large aerial orthophotograph of the scene. The result provides a unified geo-referenced map representation to permit automatic (and manual) video control and exploitation of cameras in a coordinated manner. The combined framework provides new capabilities for video sensor networks that are of significance and benefit to the broad surveillance/security community.
NASA Astrophysics Data System (ADS)
Michellier, Caroline; Kervyn, François; Tréfon, Théodore; Wolff, Eléonore
2013-04-01
GeoRisCA is a project which aims at studying the geo-risk in the Kivu region (DRC, Rwanda, Burundi), in order to support risk management. The approach developed in GeoRisCA combines methodologies from various disciplines, which will allow the analyses of seismic, volcanic and mass-movement hazards and the vulnerability assessment of the threatened elements. Vulnerability is a complex concept which is commonly defined as the susceptibility of the population, the infrastructures and the natural ecosystems to suffer from damages if a hazard occurs. The densely populated area extended from the North Kivu province in Democratic Republic of the Congo (DRC) to North Burundi and East Rwanda is vulnerable to several geohazards, such as landslides triggered by geodynamical processes (climate, seismicity, volcanism) and possibly worsen by anthropic actions. Located in the East African rift valley, the region is also characterized by a strong seismicity, with increasing people and infrastructure exposed. In addition, east DRC hosts the two most active African volcanoes: Nyiragongo and Nyamulagira. Their activity can have serious impacts, as in 2002 when Nyiragongo directly endangers the ~800.000 inhabitants of Goma city, located ~15 km to the south. Linked to passive volcanic degassing, SO2 and CO2 discharge may also increase the population vulnerability(morbidity, mortality). Focusing specifically on this region, the vulnerability assessment methodology developed in GeoRisCA takes into account "exposure to perturbations" and "adaptive capacity or resilience" of the vulnerable systems. On one hand, the exposure is identified as the potential degree of loss of a given element or set of elements at risk; i.e., the susceptibility of people, infrastructures and buildings with respect to a hazard (social vulnerability). It focuses mainly on land use, and on demographic and socio-economic factors that increase or attenuate the impacts of hazards events on local populations. On the other hand, the resilience of the individual, the household, the community, is its adaptive capacity to absorb disturbance and reorganize into a fully functioning system by anticipation, response, adaptation and recovery. A key contribution of GeoRisCA project is to assess the vulnerability to different geohazards by integrating geographic and time variability. This methodology takes into account the specificities highlighted at the regional and the local scale (urban sites). And it also considers that the vulnerability evolves with time, e.g. due to improved education, increased income, denser social networks and evolution of coping mechanisms. Using the above described methodology, one of the main objective of GeoRisCA is to developed vulnerability maps that, once associated with geohazards data, will provide decision making tools for existing preparedness and mitigation institutions.
NCBI GEO: archive for functional genomics data sets--update.
Barrett, Tanya; Wilhite, Stephen E; Ledoux, Pierre; Evangelista, Carlos; Kim, Irene F; Tomashevsky, Maxim; Marshall, Kimberly A; Phillippy, Katherine H; Sherman, Patti M; Holko, Michelle; Yefanov, Andrey; Lee, Hyeseung; Zhang, Naigong; Robertson, Cynthia L; Serova, Nadezhda; Davis, Sean; Soboleva, Alexandra
2013-01-01
The Gene Expression Omnibus (GEO, http://www.ncbi.nlm.nih.gov/geo/) is an international public repository for high-throughput microarray and next-generation sequence functional genomic data sets submitted by the research community. The resource supports archiving of raw data, processed data and metadata which are indexed, cross-linked and searchable. All data are freely available for download in a variety of formats. GEO also provides several web-based tools and strategies to assist users to query, analyse and visualize data. This article reports current status and recent database developments, including the release of GEO2R, an R-based web application that helps users analyse GEO data.
NASA Astrophysics Data System (ADS)
Gordov, Evgeny; Okladnikov, Igor; Titov, Alexander
2017-04-01
For comprehensive usage of large geospatial meteorological and climate datasets it is necessary to create a distributed software infrastructure based on the spatial data infrastructure (SDI) approach. Currently, it is generally accepted that the development of client applications as integrated elements of such infrastructure should be based on the usage of modern web and GIS technologies. The paper describes the Web GIS for complex processing and visualization of geospatial (mainly in NetCDF and PostGIS formats) datasets as an integral part of the dedicated Virtual Research Environment for comprehensive study of ongoing and possible future climate change, and analysis of their implications, providing full information and computing support for the study of economic, political and social consequences of global climate change at the global and regional levels. The Web GIS consists of two basic software parts: 1. Server-side part representing PHP applications of the SDI geoportal and realizing the functionality of interaction with computational core backend, WMS/WFS/WPS cartographical services, as well as implementing an open API for browser-based client software. Being the secondary one, this part provides a limited set of procedures accessible via standard HTTP interface. 2. Front-end part representing Web GIS client developed according to a "single page application" technology based on JavaScript libraries OpenLayers (http://openlayers.org/), ExtJS (https://www.sencha.com/products/extjs), GeoExt (http://geoext.org/). It implements application business logic and provides intuitive user interface similar to the interface of such popular desktop GIS applications, as uDIG, QuantumGIS etc. Boundless/OpenGeo architecture was used as a basis for Web-GIS client development. According to general INSPIRE requirements to data visualization Web GIS provides such standard functionality as data overview, image navigation, scrolling, scaling and graphical overlay, displaying map legends and corresponding metadata information. The specialized Web GIS client contains three basic tires: • Tier of NetCDF metadata in JSON format • Middleware tier of JavaScript objects implementing methods to work with: o NetCDF metadata o XML file of selected calculations configuration (XML task) o WMS/WFS/WPS cartographical services • Graphical user interface tier representing JavaScript objects realizing general application business logic Web-GIS developed provides computational processing services launching to support solving tasks in the area of environmental monitoring, as well as presenting calculation results in the form of WMS/WFS cartographical layers in raster (PNG, JPG, GeoTIFF), vector (KML, GML, Shape), and binary (NetCDF) formats. It has shown its effectiveness in the process of solving real climate change research problems and disseminating investigation results in cartographical formats. The work is supported by the Russian Science Foundation grant No 16-19-10257.
NASA Astrophysics Data System (ADS)
Marlow, W. A.; Cahoy, K.; Males, J.; Carlton, A.; Yoon, H.
2015-12-01
Real-time observation and monitoring of geostationary (GEO) satellites with ground-based imaging systems would be an attractive alternative to fielding high cost, long lead, space-based imagers, but ground-based observations are inherently limited by atmospheric turbulence. Adaptive optics (AO) systems are used to help ground telescopes achieve diffraction-limited seeing. AO systems have historically relied on the use of bright natural guide stars or laser guide stars projected on a layer of the upper atmosphere by ground laser systems. There are several challenges with this approach such as the sidereal motion of GEO objects relative to natural guide stars and limitations of ground-based laser guide stars; they cannot be used to correct tip-tilt, they are not point sources, and have finite angular sizes when detected at the receiver. There is a difference between the wavefront error measured using the guide star compared with the target due to cone effect, which also makes it difficult to use a distributed aperture system with a larger baseline to improve resolution. Inspired by previous concepts proposed by A.H. Greenaway, we present using a space-based laser guide starprojected from a satellite orbiting the Earth. We show that a nanosatellite-based guide star system meets the needs for imaging GEO objects using a low power laser even from 36,000 km altitude. Satellite guide star (SGS) systemswould be well above atmospheric turbulence and could provide a small angular size reference source. CubeSatsoffer inexpensive, frequent access to space at a fraction of the cost of traditional systems, and are now being deployed to geostationary orbits and on interplanetary trajectories. The fundamental CubeSat bus unit of 10 cm cubed can be combined in multiple units and offers a common form factor allowing for easy integration as secondary payloads on traditional launches and rapid testing of new technologies on-orbit. We describe a 6U CubeSat SGS measuring 10 cm x 20 cm x 30 cm with laser power on the order of milliwatts, and a commercial off the shelf based attitude determination and control system, among others. Different from standard 1U and 3U buses, the 6U form factor allows for a propulsion system for navigating around multiple targets in the GEO belt.
NASA Technical Reports Server (NTRS)
Mcmillan, J. D.
1981-01-01
The accuracy of the GEOS-3 significant waveheight estimates compared with buoy measurements of significant waveheight were determined. A global atlas of the GEOS-3 significant waveheight estimates gathered is presented. The GEOS-3 significant waveheight estimation algorithm is derived by analyzing the return waveform characteristics of the altimeter. Convergence considerations are examined, the rationale for a smoothing technique is presented and the convergence characteristics of the smoothed estimate are discussed. The GEOS-3 data are selected for comparison with buoy measurements. The GEOS-3 significant waveheight estimates are assembled in the form of a global atlas of contour maps. Both high and low sea state contour maps are presented, and the data are displayed both by seasons and for the entire duration of the GEOS-3 mission.
Through Kazan ASPERA to Modern Projects
NASA Astrophysics Data System (ADS)
Gusev, Alexander; Kitiashvili, Irina; Petrova, Natasha
Now the European Union form the Sixth Framework Programme. One of its the objects of the EU Programme is opening national researches and training programmes. The Russian PhD students and young astronomers have business and financial difficulties in access to modern databases and astronomical projects and so they has not been included in European overview of priorities. Modern requirements to the organization of observant projects on powerful telescopes assumes painstaking scientific computer preparation of the application. A rigid competition for observation time assume preliminary computer modeling of target object for success of the application. Kazan AstroGeoPhysics Partnership
Vision-Based Geo-Monitoring - A New Approach for an Automated System
NASA Astrophysics Data System (ADS)
Wagner, A.; Reiterer, A.; Wasmeier, P.; Rieke-Zapp, D.; Wunderlich, T.
2012-04-01
The necessity for monitoring geo-risk areas such as rock slides is growing due to the increasing probability of such events caused by environmental change. Life with threat becomes to a calculable risk by geodetic deformation monitoring. An in-depth monitoring concept with modern measurement technologies allows the estimation of the hazard potential and the prediction of life-threatening situations. The movements can be monitored by sensors, placed in the unstable slope area. In most cases, it is necessary to enter the regions at risk in order to place the sensors and maintain them. Using long-range monitoring systems (e.g. terrestrial laser scanners, total stations, ground based synthetic aperture radar) allows avoiding this risk. To close the gap between the existing low-resolution, medium-accuracy sensors and conventional (co-operative target-based) surveying methods, image-assisted total stations (IATS) are a suggestive solution. IATS offer the user (e.g. metrology expert) an image capturing system (CCD/CMOS camera) in addition to 3D point measurements. The images of the telescope's visual field are projected onto the camera's chip. With appropriate calibration, these images are accurately geo-referenced and oriented since the horizontal and vertical angles of rotation are continuously recorded. The oriented images can directly be used for direction measurements with no need for object control points or further photogrammetric orientation processes. IATS are able to provide high density deformation fields with high accuracy (down to mm range), in all three coordinate directions. Tests have shown that with suitable image processing measurements a precision of 0.05 pixel ± 0.04·σ is possible (which corresponds to 0.03 mgon ± 0.04·σ). These results have to be seen under the consideration that such measurements are image-based only. For measuring in 3D object space the precision of pointing has to be taken into account. IATS can be used in two different ways: (1) combining two measurement systems and measuring object points by spatial intersection, or (2) using one measurement system and combining image-based techniques with the integrated distance measurement unit. Beside the system configuration, the detection of features inside the captured images can be done on the basis of different approaches, e.g. template-, edge-, and/or point-based methods. Our system is able to select a suitable algorithm based on different object characteristics, such as object geometry, texture, behaviour, etc. The long-term objective is the research, development and installation of a fully-automated measurement system, including a data analysis and interpretation component. Acknowledgments: The presented research has been supported by the Alexander von Humboldt Foundation, and by the European Sciences Foundation (ESF).
How semantics can inform the geological mapping process and support intelligent queries
NASA Astrophysics Data System (ADS)
Lombardo, Vincenzo; Piana, Fabrizio; Mimmo, Dario
2017-04-01
The geologic mapping process requires the organization of data according to the general knowledge about the objects, namely the geologic units, and to the objectives of a graphic representation of such objects in a map, following an established model of geotectonic evolution. Semantics can greatly help such a process in two concerns: the provision of a terminological base to name and classify the objects of the map; on the other, the implementation of a machine-readable encoding of the geologic knowledge base supports the application of reasoning mechanisms and the derivation of novel properties and relations about the objects of the map. The OntoGeonous initiative has built a terminological base of geological knowledge in a machine-readable format, following the Semantic Web tenets and the Linked Data paradigm. The major knowledge sources of the OntoGeonous initiative are GeoScience Markup Language schemata and vocabularies (through its last version, GeoSciML 4, 2015, published by the IUGS CGI Commission) and the INSPIRE "Data Specification on Geology" directives (an operative simplification of GeoSciML, published by INSPIRE Thematic Working Group Geology of the European Commission). The Linked Data paradigm has been exploited by linking (without replicating, to avoid inconsistencies) the already existing machine-readable encoding for some specific domains, such as the lithology domain (vocabulary Simple Lithology) and the geochronologic time scale (ontology "gts"). Finally, for the upper level knowledge, shared across several geologic domains, we have resorted to NASA SWEET ontology. The OntoGeonous initiative has also produced a wiki that explains how the geologic knowledge has been encoded from shared geoscience vocabularies (https://www.di.unito.it/wikigeo/). In particular, the sections dedicated to axiomatization will support the construction of an appropriate data base schema that can be then filled with the objects of the map. This contribution will discuss how the formal encoding of the geological knowledge opens new perspectives for the analysis and representation of the geological systems. In fact, once that the major concepts are defined, the resulting formal conceptual model of the geologic system can hold across different technical and scientific communities. Furthermore, this would allow for a semi-automatic or automatic classification of the cartographic database, where a significant number of properties (attributes) of the recorded instances could be inferred through computational reasoning. So, for example, the system can be queried for showing the instances that satisfy some property (e.g., "Retrieve all the lithostratigraphic units composed of clastic sedimentary rock") or for classifying some unit according to the properties holding for that unit (e.g., "What is the class of the geologic unit composed of siltstone material?").
NASA Astrophysics Data System (ADS)
Hsu, L.; Lehnert, K. A.; Carbotte, S. M.; Arko, R. A.; Ferrini, V.; O'hara, S. H.; Walker, J. D.
2012-12-01
The Integrated Earth Data Applications (IEDA) facility maintains multiple data systems with a wide range of solid earth data types from the marine, terrestrial, and polar environments. Examples of the different data types include syntheses of ultra-high resolution seafloor bathymetry collected on large collaborative cruises and analytical geochemistry measurements collected by single investigators in small, unique projects. These different data types have historically been channeled into separate, discipline-specific databases with search and retrieval tailored for the specific data type. However, a current major goal is to integrate data from different systems to allow interdisciplinary data discovery and scientific analysis. To increase discovery and access across these heterogeneous systems, IEDA employs several unique IDs, including sample IDs (International Geo Sample Number, IGSN), person IDs (GeoPass ID), funding award IDs (NSF Award Number), cruise IDs (from the Marine Geoscience Data System Expedition Metadata Catalog), dataset IDs (DOIs), and publication IDs (DOIs). These IDs allow linking of a sample registry (System for Earth SAmple Registration), data libraries and repositories (e.g. Geochemical Research Library, Marine Geoscience Data System), integrated synthesis databases (e.g. EarthChem Portal, PetDB), and investigator services (IEDA Data Compliance Tool). The linked systems allow efficient discovery of related data across different levels of granularity. In addition, IEDA data systems maintain links with several external data systems, including digital journal publishers. Links have been established between the EarthChem Portal and ScienceDirect through publication DOIs, returning sample-level objects and geochemical analyses for a particular publication. Linking IEDA-hosted data to digital publications with IGSNs at the sample level and with IEDA-allocated dataset DOIs are under development. As an example, an individual investigator could sign up for a GeoPass account ID, write a proposal to NSF and create a data plan using the IEDA Data Management Plan Tool. Having received the grant, the investigator then collects rock samples on a scientific cruise from dredges and registers the samples with IGSNs. The investigator then performs analytical geochemistry on the samples, and submits the full dataset to the Geochemical Resource Library for a dataset DOI. Finally, the investigator writes an article that is published in Science Direct. Knowing any of the following IDs: Investigator GeoPass ID, NSF Award Number, Cruise ID, Sample IGSNs, dataset DOI, or publication DOI, a user would be able to navigate to all samples, datasets, and publications in IEDA and external systems. Use of persistent identifiers to link heterogeneous data systems in IEDA thus increases access, discovery, and proper citation of hard-earned investigator datasets.
How can LCA approaches contribute to improve geo-cycles management
NASA Astrophysics Data System (ADS)
Carreiras, M.; Ferreira, A. J. D.; Esteves, T. C. J.; Delgado, F.; Andrade, F.; Franco, J.; Pereira, C. D.
2012-04-01
Climate change and land use have become a major challenge for mankind and the natural environment. Greenhouse gas (GHG) emissions released into the atmosphere in ever rapidly growing volumes are most likely to be responsible for this change. Carbon dioxide gas (CO2) is suggested to be the main cause of global warming. Carbon reduction is the key to preventing this, for example, by enhancing energy efficiency and mitigating carbon emissions by means of green energy and adjusting the use of natural resources. Different activities produce distinguish impacts, and each product generates specific impacts on nature. The impact of man activities in the geo-cycles is of paramount importance in what concerns long term sustainability. Nevertheless, the environmental and sustainability impacts of different approaches and techniques of ecosystem management is a difficult question that can be assessed using LCA techniques LCA is a technique to assess environmental impacts associated with all the stages of a product's life from-cradle-to-grave. Based on that, LCA can be effective in supporting the assessment of decision making on complex sustainability issues because it can integrate the diversity of impacts categories guise and it can be adapted to a large variety of contexts. By incorporating quantitative data LCA allows decision makers to include a full range of economic, environmental, social and technical criteria. The integrated framework is configured such that the pros and cons of alternative environmental and energy strategies can be measured in terms of their ability to achieve the overall goals and objectives of the sustainable development, while satisfying the pollution control requirements. Because it is holistic, integrate and dynamic, this approach represents a state of the art tool for enhance the sustainable development of a sector, allowing a more transparent and participated management, a basic instrument for improved competitiveness. This approach may serve as a basis for prioritizing industrial technologies, procedures or materials, based on the reduction of impacts. The ECODEEP project intents to contribute to the competitiveness of the national agri-food sector in particular the Central Region of Portugal. Through the development of eco-efficiency tools it allows a more careful management of inputs, optimizing consumption energy and raw materials. ECODEEP seeks to improve the performance of the sector, allowing an improvement of production processes and a reduction of the investment on end-of-line solutions, therefore reducing products costs, which become more competitive, while reducing the impact on geo-cycles and the ecosystems. The overall purpose of this paper is, based on a case study, discuss the use of LCA approach to improve overall competitiveness while reducing the impact over the geo-cycles and the environment in general.
NASA Astrophysics Data System (ADS)
Du, X.; Leinenkugel, P.; Guo, H.; Kuenzer, C.
2017-12-01
During the recent decades, global coasts are undergoing tremendous change due to accelerating socio-economic growth, which has severe effects on the functioning of global coastal systems. In view of this, accurate, timely, and area-wide global information on natural as well as anthropogenic processes in the coastal zone are of paramount importance for sustainable coastal development. A broad range of freely available satellite derived products, and open geo-datasets, as well as statistics with global coverage exist that have not yet been fully exploited to evaluate human development patterns in coastal areas. In this study, we demonstrate the potential of freely and openly available EO and GEO data sets for characterizing and evaluating human development in coastal zones on large scales. Therefore, different geo-spatial dataset such as Global Urban Footprint (GUF), Open Street Map (OSM), time series of Global Human Settlement Layer (GHSL) and Climate Change Initiative (CCI) Land cover were acquired for the entire continental coast of Asia, defined as the terrestrial area 100 km from the coastline. In order to extract indices for the coastline, a reference structure was developed allowing the integration of a 2D spatial pattern of a given parameter to a certain location along the coast line. Based on this reference structure statistics for the coast were calculated every 5 km parallel to the coast line as well as for four different distance intervals from the coast. The results demonstrate the highly unequal distribution of coastal development with respect to urban and agricultural usage in Asia, with large differences between and within different countries. China coasts show the highest overall patterns of urban development, while countries such as Pakistan and Myanmar show comparably low levels with nearly no development evident absence from coastal metropolitan areas. Furthermore, a clear trend of decreasing urban development is evident with increasing distance from the coast. This study highlights the potential of global geo-spatial data products for deriving anthropogenic development indicators that can support the evaluation and monitoring for sustainable development of coastal zones, while also discussing the shortcomings of these datasets for such purposes.
NASA Astrophysics Data System (ADS)
Turner, Alexander J.; Jacob, Daniel J.; Benmergui, Joshua; Brandman, Jeremy; White, Laurent; Randles, Cynthia A.
2018-06-01
Anthropogenic methane emissions originate from a large number of fine-scale and often transient point sources. Satellite observations of atmospheric methane columns are an attractive approach for monitoring these emissions but have limitations from instrument precision, pixel resolution, and measurement frequency. Dense observations will soon be available in both low-Earth and geostationary orbits, but the extent to which they can provide fine-scale information on methane sources has yet to be explored. Here we present an observation system simulation experiment (OSSE) to assess the capabilities of different satellite observing system configurations. We conduct a 1-week WRF-STILT simulation to generate methane column footprints at 1.3 × 1.3 km2 spatial resolution and hourly temporal resolution over a 290 × 235 km2 domain in the Barnett Shale, a major oil and gas field in Texas with a large number of point sources. We sub-sample these footprints to match the observing characteristics of the recently launched TROPOMI instrument (7 × 7 km2 pixels, 11 ppb precision, daily frequency), the planned GeoCARB instrument (2.7 × 3.0 km2 pixels, 4 ppb precision, nominal twice-daily frequency), and other proposed observing configurations. The information content of the various observing systems is evaluated using the Fisher information matrix and its eigenvalues. We find that a week of TROPOMI observations should provide information on temporally invariant emissions at ˜ 30 km spatial resolution. GeoCARB should provide information available on temporally invariant emissions ˜ 2-7 km spatial resolution depending on sampling frequency (hourly to daily). Improvements to the instrument precision yield greater increases in information content than improved sampling frequency. A precision better than 6 ppb is critical for GeoCARB to achieve fine resolution of emissions. Transient emissions would be missed with either TROPOMI or GeoCARB. An aspirational high-resolution geostationary instrument with 1.3 × 1.3 km2 pixel resolution, hourly return time, and 1 ppb precision would effectively constrain the temporally invariant emissions in the Barnett Shale at the kilometer scale and provide some information on hourly variability of sources.
Macrostrat and GeoDeepDive: A Platform for Geological Data Integration and Deep-Time Research
NASA Astrophysics Data System (ADS)
Husson, J. M.; Peters, S. E.; Ross, I.; Czaplewski, J. J.
2016-12-01
Characterizing the quantity, lithology, age, and properties of rocks and sediments in the upper crust is central to many questions in Earth science. Although a large number of geological maps, regional syntheses, and sample-based measurements have been published in a variety of formats, there is no system for integrating and accessing rock record-derived data or for facilitating the large-scale quantitative interrogation of the physical, chemical, and biological properties of Earth's crust. Here we describe two data resources that aim to overcome some of these limitations: 1) Macrostrat, a geospatial database and supporting cyberinfrastructure that is designed to enable quantitative analyses of the entire assemblage of surface and subsurface sedimentary, igneous and metamorphic rocks, and 2) GeoDeepDive, a digital library and high throughput computing system designed to facilitate the location and extraction of information and data from the published literature. Macrostrat currently contains general summaries of the age and lithology of rocks and sediments in the upper crust at 1,474 regions in North and Central America, the Caribbean, New Zealand, and the deep sea. Distributed among these geographic regions are nearly 34,000 lithologically and chronologically-defined geological units, many of which are linked to a bedrock geologic map database with more than 1.7 million globally distributed units. Sample-derived data, including fossil occurrences in the Paleobiology Database and more than 180,000 geochemical and outcrop-derived measurements are linked to Macrostrat units and/or lithologies within those units. The rock names, lithological terms, and geological time intervals that are applied to Macrostrat units define a hierarchical, spatially and temporally indexed vocabulary that is leveraged by GeoDeepDive in order to provide researchers access to data within the scientific literature as it is published and ingested into the infrastructure. All data in Macrostrat are accessible via an Application Programming Interface, which enables the development of mobile and analytical applications. The GeoDeepDive infrastructure also supports the development and execution of applications that are tailored to the specific, literature-based data location and extraction needs of geoscientists.
Krüger, Rejko; Sharma, Manu; Riess, Olaf; Gasser, Thomas; Van Broeckhoven, Christine; Theuns, Jessie; Aasly, Jan; Annesi, Grazia; Bentivoglio, Anna Rita; Brice, Alexis; Djarmati, Ana; Elbaz, Alexis; Farrer, Matthew; Ferrarese, Carlo; Gibson, J Mark; Hadjigeorgiou, Georgios M; Hattori, Nobutaka; Ioannidis, John P A; Jasinska-Myga, Barbara; Klein, Christine; Lambert, Jean-Charles; Lesage, Suzanne; Lin, Juei-Jueng; Lynch, Timothy; Mellick, George D; de Nigris, Francesa; Opala, Grzegorz; Prigione, Alessandro; Quattrone, Aldo; Ross, Owen A; Satake, Wataru; Silburn, Peter A; Tan, Eng King; Toda, Tatsushi; Tomiyama, Hiroyuki; Wirdefeldt, Karin; Wszolek, Zbigniew; Xiromerisiou, Georgia; Maraganore, Demetrius M
2011-03-01
High-profile studies have provided conflicting results regarding the involvement of the Omi/HtrA2 gene in Parkinson's disease (PD) susceptibility. Therefore, we performed a large-scale analysis of the association of common Omi/HtrA2 variants in the Genetic Epidemiology of Parkinson's disease (GEO-PD) consortium. GEO-PD sites provided clinical and genetic data including affection status, gender, ethnicity, age at study, age at examination (all subjects); age at onset and family history of PD (patients). Genotyping was performed for the five most informative SNPs spanning the Omi/HtrA2 gene in approximately 2-3 kb intervals (rs10779958, rs2231250, rs72470544, rs1183739, rs2241028). Fixed as well as random effect models were used to provide summary risk estimates of Omi/HtrA2 variants. The 20 GEO-PD sites provided data for 6378 cases and 8880 controls. No overall significant associations for the five Omi/HtrA2 SNPs and PD were observed using either fixed effect or random effect models. The summary odds ratios ranged between 0.98 and 1.08 and the estimates of between-study heterogeneity were not large (non-significant Q statistics for all 5 SNPs; I(2) estimates 0-28%). Trends for association were seen for participants of Scandinavian descent for rs2241028 (OR 1.41, p=0.04) and for rs1183739 for age at examination (cut-off 65 years; OR 1.17, p=0.02), but these would not be significant after adjusting for multiple comparisons and their Bayes factors were only modest. This largest association study performed to define the role of any gene in the pathogenesis of Parkinson's disease revealed no overall strong association of Omi/HtrA2 variants with PD in populations worldwide. Copyright © 2009 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Cao, Shuo; Zhu, Zong-Hong
2014-10-01
Using relatively complete observational data concerning four angular diameter distance (ADD) measurements and combined SN +GRB observations representing current luminosity distance (LD) data, this paper investigates the compatibility of these two cosmological distances considering three classes of dark energy equation of state (EoS) reconstruction. In particular, we use strongly gravitationally lensed systems from various large systematic gravitational lens surveys and galaxy clusters, which yield the Hubble constant independent ratio between two angular diameter distances Dl s/Ds data. Our results demonstrate that, with more general categories of standard ruler data, ADD and LD data are compatible at 1 σ level. Second, we note that consistency between ADD and LD data is maintained irrespective of the EoS parametrizations: there is a good match between the universally explored Chevalier-Polarski-Linder model and other formulations of cosmic equation of state. Especially for the truncated generalized equation of state (GEoS) model with β =-2 , the conclusions obtained with ADD and LD are almost the same. Finally, statistical analysis of generalized dark energy equation of state performed on four classes of ADD data provides stringent constraints on the EoS parameters w0 , wβ, and β , which suggest that dark energy was a subdominant component at early times. Moreover, the GEoS parametrization with β ≃1 seems to be a more favorable two-parameter model to characterize the cosmic equation of state, because the combined angular diameter distance data (SGL +CBF +BAO +WMAP 9 ) provide the best-fit value β =0.75 1-0.480+0.465 .
NASA Technical Reports Server (NTRS)
Lyster, Peter M.; Guo, J.; Clune, T.; Larson, J. W.; Atlas, Robert (Technical Monitor)
2001-01-01
The computational complexity of algorithms for Four Dimensional Data Assimilation (4DDA) at NASA's Data Assimilation Office (DAO) is discussed. In 4DDA, observations are assimilated with the output of a dynamical model to generate best-estimates of the states of the system. It is thus a mapping problem, whereby scattered observations are converted into regular accurate maps of wind, temperature, moisture and other variables. The DAO is developing and using 4DDA algorithms that provide these datasets, or analyses, in support of Earth System Science research. Two large-scale algorithms are discussed. The first approach, the Goddard Earth Observing System Data Assimilation System (GEOS DAS), uses an atmospheric general circulation model (GCM) and an observation-space based analysis system, the Physical-space Statistical Analysis System (PSAS). GEOS DAS is very similar to global meteorological weather forecasting data assimilation systems, but is used at NASA for climate research. Systems of this size typically run at between 1 and 20 gigaflop/s. The second approach, the Kalman filter, uses a more consistent algorithm to determine the forecast error covariance matrix than does GEOS DAS. For atmospheric assimilation, the gridded dynamical fields typically have More than 10(exp 6) variables, therefore the full error covariance matrix may be in excess of a teraword. For the Kalman filter this problem can easily scale to petaflop/s proportions. We discuss the computational complexity of GEOS DAS and our implementation of the Kalman filter. We also discuss and quantify some of the technical issues and limitations in developing efficient, in terms of wall clock time, and scalable parallel implementations of the algorithms.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Holliday, Michael; Camilloni, Carlo; Armstrong, Geoffrey S.
2015-05-26
Thermophilic proteins have found extensive use in research and industrial applications due to their high stability and functionality at elevated temperatures while simultaneously providing valuable insight into our understanding of protein folding, stability, dynamics, and function. Cyclophilins, a ubiquitously expressed family of peptidyl-prolyl isomerases with a range of biological functions and disease associations, have been utilized both for conferring stress tolerances and in exploring the link between conformational dynamics and enzymatic function. To date, however, no active thermophilic cyclophilin has been fully biophysically characterized. Here, we determine the structure of a thermophilic cyclophilin (GeoCyp) from Geobacillus kaustophilus, characterize its dynamicmore » motions over several timescales using an array of methodologies that include chemical shift-based methods and relaxation experiments over a range of temperatures, and measure catalytic activity over a range of temperatures in order to compare structure, dynamics, and function to a mesophilic counterpart, human Cyclophilin A (CypA). Unlike most thermophile/mesophile pairs, GeoCyp catalysis is not substantially impaired at low temperatures as compared to CypA, retaining ~70% of the activity of its mesophilic counterpart. Examination of substrate-bound ensembles reveals a mechanism by which the two cyclophilins may have adapted to their environments through altering dynamic loop motions and a critical residue that acts as a clamp to regulate substrate binding differentially in CypA and GeoCyp. Despite subtle differences in conformational movements, dynamics over fast (ps-ns) and slow (μs) timescales are largely conserved between the two proteins.« less
Studying and understanding the environmental impacts of the Three Gorges Dam in China
NASA Astrophysics Data System (ADS)
Schönbrodt-Stitt, Sarah; Stumpf, Felix; Schmidt, Karsten; Althaus, Paul; Bi, Renneng; Bieger, Katrin; Buzzo, Giovanni; Dumperth, Christian; Fohrer, Nicola; Rohn, Joachim; Strehmel, Alexander; Udelhoven, Thomas; Wei, Xiang; Zimmermann, Karsten; Scholten, Thomas
2013-04-01
Since its planning phase and its completion and start of operation in 2009, the Three Gorges Dam (TGD) at the Yangtze River, has been discussed in a controversial manner. Due to considerable resettlements along with the associated expansion of the infrastructure network and large-scale shifts in land use and management, the TGD in Central China is among the most prominent human-induced examples for large-scale environmental impacts. As a consequence of the rapid ecosystem changes, the region is largely characterized by an enormous boost of typical geo-risks such as soil erosion, mass movements, and diffuse sediment and matter fluxes into the reservoir. Within the joint research project YANGTZE-GEO, Chinese and German scientists jointly focus on the human-induced environmental changes in the reservoir of the TGD after the impoundment of the Yangtze River and its tributaries. An integrative approach was set up in order to combine multi-scale investigation methods and state-of-the-art techniques from soil science, geology, hydrology, geophysics, geodesy, remote sensing, and data survey and monitoring. By means of eco-hydrological and soil erosion modeling, geo-statistical approaches such as digital soil mapping and Artificial Neuronal Networks, spatially and temporally differentiated simulation of the water budget as well as the balance of diffuse matter such as phosphorus and sediment, three-dimensional dynamic modeling, seismoacoustics and terrestrial radarinterferometry, multi-temporal land use classification from recent and historical remote sensing data and laser scanning, the research aims at (i) the understanding of the mechanisms and anthropogenic and environmental control factors of the environmental changes in the highly dynamic region and (ii) the development of spatially explicit land use options and recommendations for a sustainable land use management. Finally, based on the integrate modelling, we aim at the conception of a monitoring- and measuring network and early-warning system including local and regional authorities. Thus, the studies will contribute to a better understanding of the dimensions and dynamics of the ecological consequences of such large dam projects at the Yangtze River and worldwide.
Space Weather Influence on Relative Motion Control using the Touchless Electrostatic Tractor
NASA Astrophysics Data System (ADS)
Hogan, Erik A.; Schaub, Hanspeter
2016-09-01
With recent interest in the use of electrostatic forces for contactless tugging and attitude control of noncooperative objects for orbital servicing and active debris mitigation, the need for a method of remote charge control arises. In this paper, the use of a directed electron beam for remote charge control is considered in conjunction with the relative motion control. A tug vehicle emits an electron beam onto a deputy object, charging it negatively. At the same time, the tug is charged positively due to beam emission, resulting in an attractive electrostatic force. The relative position feedback control between the tug and the passive debris object is studied subject to the charging being created through an electron beam. Employing the nominal variations of the GEO space weather conditions across longitude slots, two electrostatic tugging strategies are considered. First, the electron beam current is adjusted throughout the orbit in order to maximize this resulting electrostatic force. This open-loop control strategy compensates for changes in the nominally expected local space weather environment in the GEO region to adjust for fluctuations in the local plasma return currents. Second, the performance impact of using a fixed electron beam current on the electrostatic tractor is studied if the same natural space weather variations are assumed. The fixed electron beam current shows a minor performance penalty (<5 %) while providing a much simpler implementation that does not require any knowledge of local space weather conditions.
GeoFrame Walker Lane: Overview, Rationale, and Objectives
NASA Astrophysics Data System (ADS)
Stockli, D. F.
2006-12-01
GeoFrame is an integrative geologic initiative that takes a multi-dimensional view of the building and modification of the North American continent by systematic integration of geologic and geochronometric investigations and the results from unprecedented geophysical imaging as part of the Earthscope Program. The GeoFrame effort envisions these focus site investigations to entail map-scale arrays of passive source seismic receivers and associated active source seismic studies and complementary geophysics in conjunction with geologic-based synthesis and targeted studies. One of these focus sites is the Walker Lane region in eastern California and western Nevada, situated between the Basin and Range province and the unextended Sierra Nevada block. This GeoFrame focus site workshop is particularly timely given the deployment schedule of the USArray "BigFoot" array. The Walker Lane intraplate deformation zone accommodates nearly ~25% of present-day relative motion between the Pacific and North American plates and might represent an incipient plate boundary. It provides a world-class example of the present modification of continental lithosphere by the process of transcurrent faulting and rifting and offers the opportunity to seamlessly integrate surface geology, structural geology, petrology, geo- and thermochronology, and the history of the continental lithosphere with ongoing processes in the Earth's mantle. It affords opportunities to address a number of questions posed within Earthscope such as: mechanisms of strain transfer, the role of lithospheric rheology in strain localization and seismic response, the nature and timescales of transient fault behavior, and the role of magmas and fluids in deforming lithosphere. Implicit in the design and implementation of Earthscope is the recognition that progress on issues such as these requires an integrative geophysical and geological investigation of the Walker Lane. As such, it will open new avenues of collaboration and identify new research needs and opportunities. We anticipate the integration of results and efforts with ongoing Earthscope projects, such as Sierra Nevada efforts of SNEP as well as the NSF Margins Rupturing of Continental Lithosphere (RCL) initiative in the Gulf of California by continuing the work onshore from the Gulf of California to the north into Nevada.
GEOSS authentication/authorization services: a Broker-based approach
NASA Astrophysics Data System (ADS)
Santoro, M.; Nativi, S.
2014-12-01
The vision of the Global Earth Observation System of Systems (GEOSS) is the achievement of societal benefits through voluntary contribution and sharing of resources to better understand the relationships between the society and the environment where we live. The GEOSS Common Infrastructure (GCI) allows users to search, access, and use the resources contributed by the GEOSS members. The GEO DAB (Discovery and Access Broker) is the GCI component in charge of interconnecting the heterogeneous data systems contributing to GEOSS. Client applications (i.e. the portals and apps) can connect to GEO DAB as a unique entry point to discover and access resources available through GCI, with no need to implement the many service protocols and models applied by the GEOSS data providers. The GEO DAB implements the brokering approach (Nativi et al., 2013) to build a flexible and scalable System of Systems. User authentication/authorization functionality is becoming more and more important for GEOSS data providers and users. The Providers ask for information about who accessed their resources and, in some cases, want to limit the data download. The Users ask for a profiled interaction with the system based on their needs and expertise level. Besides, authentication and authorization is necessary for GEOSS to provide moderated social services - e.g. feedback messages, data "fit for use" comments, etc. In keeping with the GEOSS principles of building on existing systems and lowering entry-barriers for users, an objective of the authentication/authorization development was to support existing and well-used users' credentials (e.g. Google, Twitter, etc.). Due to the heterogeneity of technologies used by the different providers and applications, a broker-based approach for the authentication/authorization was introduced as a new functionality of GEO DAB. This new capability will be demonstrated at the next GEO XI Plenary (November 2014). This work will be presented and discussed. Refenrences Nativi, S.; Craglia, M.; Pearlman, J., "Earth Science Infrastructures Interoperability: The Brokering Approach," Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of , vol.6, no.3, pp.1118,1129, June 2013
Outreach and education from EuroGeoMoonMars2009 Field Campaign in Utah
NASA Astrophysics Data System (ADS)
Foing, Bernard H.
The goal of the EuroGeoMoonMars mission at Utah Desert Research station(from 24 January to 28 February 2009) was to demonstrate instruments from ExoGeoLab pilot project, to support the interpretation of ongoing lunar and planetary missions, to validate a procedure for surface in-situ and return science, to study human performance aspects, and perform outreach and education projects. The EuroGeoMoonMars campaign included four sets of objectives: 1) Technology demonstration aspects: a set of instruments were deployed, tested, assessed, and training was provided to scientists using them in subsequent rotations 2) Research aspects: a series of field science and exploration investigations were conducted in geology, geochemistry, biology, astronomy, with synergies with space missions and research from planetary surfaces and Earth extreme environments. 3) Human crew related aspects, i.e. (a) evaluation of the different functions and interfaces of a planetary habitat, (b) crew time organization in this habitat, (c) evaluation of man-machine interfaces of science and technical equipment; 4) Education, outreach, communications, multi-cultural public relations Outreach, education and inspiration: We produced written, pictures, and video materials that can be used for education, outreach and public relations. Daily reports were posted on the MDRS website. We had during the Technical crew preparation, the visit of film producer Mark Arabella and film crew for a Moon related National Geographics documentary "Earth without the Moon". Two media crew visitors stayed also in the Hab to film our activities documenting the operational, research, human, simulation, imaginative and fantasy aspects of Moon-Mars-extreme Earth exploration. They contributed a journalist report, and even performed an EVA outreach filming a sortie to Hanksville village on Earth. Other film and journalists visited the EuroGeoMars crew for interviews and exchange. Specific crew reports were also prepared for some national and international communication channels, including Plan`te Mars, RTBF, ILEWG, COSPAR, IAF, IAA. We thank ILEWG, NASA Ames, ESA, the Mars society, VU Amsterdam and collaborating institutes for supporting the campaign.
[Causes for change in producing areas of geo-authentic herbs].
Liang, Fei; Li, Jian; Zhang, Wei; Zhang, Rui-Xian
2013-05-01
Geo-authentic herbs lay stress on their producing areas. The producing areas of most geo-authentic herbs have never changed since the ancient times. However, many other geo-authentic herbs have experienced significant changes in the long history. There are two main causes for the change in producing areas of herbs-change of natural environment and development of human society, which are restricted by each other and play a great role throughout the development process of geo-authentic herbs.
Structural studies of gels and gel-glasses in the SiO2-GeO2 system using vibrational spectroscopy
NASA Technical Reports Server (NTRS)
Mukherjee, Shyama P.; Sharma, Shiv K.
1986-01-01
GeO2 gel and gels in the SiO2-GeO2 system synthesized by the hydrolytic polycondensation of metal alkoxides have been studied by infrared and Raman spectroscopic techniques. The molecular structures, hydroxyl contents, and crystallinity of gels and gel-glasses in relation to the thermal history and GeO2 concentration were investigated. The binary compositions having up to 70 mol percent GeO2 were examined.
NASA Technical Reports Server (NTRS)
Suarez, Max J. (Editor); Takacs, Lawrence L.; Molod, Andrea; Wang, Tina
1994-01-01
This technical report documents Version 1 of the Goddard Earth Observing System (GEOS) General Circulation Model (GCM). The GEOS-1 GCM is being used by NASA's Data Assimilation Office (DAO) to produce multiyear data sets for climate research. This report provides a documentation of the model components used in the GEOS-1 GCM, a complete description of model diagnostics available, and a User's Guide to facilitate GEOS-1 GCM experiments.
Homodyne BPSK-based optical inter-satellite communication links
NASA Astrophysics Data System (ADS)
Lange, Robert; Smutny, Berry
2007-02-01
Summer 2007, Tesat will verify laser communication terminals based on homodyne BPSK (binary phase shift keying) in-orbit. A 5.625 Gbps LEO-LEO laser communication link, established between the German satellite TerraSAR-X and the US satellite NFIRE, shall demonstrate the performance and advantages of laser communication. End of 2006, a further program has been kicked-off to demonstrate the performance of ~2 Gbps LEO-GEO laser communication links. The link is part of a data relais from the German LEO satellite TanDEM-X via a Geo satellite to ground. The LEO-to-GEO laser commmunication link can be extended to further ~2 Gpbs GEO-GEO, and GEO-to-ground links.
GEOS-5 Chemistry Transport Model User's Guide
NASA Technical Reports Server (NTRS)
Kouatchou, J.; Molod, A.; Nielsen, J. E.; Auer, B.; Putman, W.; Clune, T.
2015-01-01
The Goddard Earth Observing System version 5 (GEOS-5) General Circulation Model (GCM) makes use of the Earth System Modeling Framework (ESMF) to enable model configurations with many functions. One of the options of the GEOS-5 GCM is the GEOS-5 Chemistry Transport Model (GEOS-5 CTM), which is an offline simulation of chemistry and constituent transport driven by a specified meteorology and other model output fields. This document describes the basic components of the GEOS-5 CTM, and is a user's guide on to how to obtain and run simulations on the NCCS Discover platform. In addition, we provide information on how to change the model configuration input files to meet users' needs.
NCBI GEO: archive for functional genomics data sets—update
Barrett, Tanya; Wilhite, Stephen E.; Ledoux, Pierre; Evangelista, Carlos; Kim, Irene F.; Tomashevsky, Maxim; Marshall, Kimberly A.; Phillippy, Katherine H.; Sherman, Patti M.; Holko, Michelle; Yefanov, Andrey; Lee, Hyeseung; Zhang, Naigong; Robertson, Cynthia L.; Serova, Nadezhda; Davis, Sean; Soboleva, Alexandra
2013-01-01
The Gene Expression Omnibus (GEO, http://www.ncbi.nlm.nih.gov/geo/) is an international public repository for high-throughput microarray and next-generation sequence functional genomic data sets submitted by the research community. The resource supports archiving of raw data, processed data and metadata which are indexed, cross-linked and searchable. All data are freely available for download in a variety of formats. GEO also provides several web-based tools and strategies to assist users to query, analyse and visualize data. This article reports current status and recent database developments, including the release of GEO2R, an R-based web application that helps users analyse GEO data. PMID:23193258
How Have States Used Executive Orders to Address Public Health?
Gakh, Maxim; Callahan, Karen; Goodie, Aaliyah; Rutkow, Lainie
2018-06-07
Gubernatorial executive orders (GEOs) are important, yet poorly understood, public health tools. We analyzed health-related GEOs nationwide using a modified legal mapping approach. We searched Westlaw's Netscan Executive Orders database for orders issued between 2008 and 2014. Search terms were generated from the Healthy People 2020 Leading Health Indicators (LHIs). GEOs were screened with data abstracted and analyzed on the basis of LHIs, states, years, and characteristics identified in previous literature. We found differences in GEOs issued per LHI. Of the 303 unique orders, they ranged from 32 to 53 issued per year and 0 to 45 issued per state. Most GEOs managed governmental public health functions, required collaboration, and mandated studying problems. Fewer directly addressed health equity, chronic disease, and resource deployment. Gubernatorial authority and political and institutional factors appear relevant to GEO issuance. GEOs offer means to institute public health policies and should be considered by public health professionals.
A New Look at the GEO and Near-GEO Regimes: Operations, Disposals, and Debris
NASA Technical Reports Server (NTRS)
Johnson, Nicholas
2011-01-01
Since 1963 more than 900 spacecraft and more than 200 launch vehicle upper stages have been inserted into the vicinity of the geosynchronous regime. Equally important, more than 300 spacecraft have been maneuvered into disposal orbits at mission termination to alleviate unnecessary congestion in the finite GEO region. However, the number of GEO satellites continues to grow, and evidence exists of a substantial small debris population. In addition, the operational modes of an increasing number of GEO spacecraft differ from those of their predecessors of several decades ago, including more frequent utilization of inclined and eccentric geosynchronous orbits. Consequently, the nature of the GEO regime and its immediate surroundings is evolving from well-known classical characteristics. This paper takes a fresh look at the GEO satellite population and the near- and far-term environmental implications of the region, including the effects of national and international debris mitigation measures.
Observation-Corrected Precipitation Estimates in GEOS-5
NASA Technical Reports Server (NTRS)
Reichle, Rolf H.; Liu, Qing
2014-01-01
Several GEOS-5 applications, including the GEOS-5 seasonal forecasting system and the MERRA-Land data product, rely on global precipitation data that have been corrected with satellite and or gauge-based precipitation observations. This document describes the methodology used to generate the corrected precipitation estimates and their use in GEOS-5 applications. The corrected precipitation estimates are derived by disaggregating publicly available, observationally based, global precipitation products from daily or pentad totals to hourly accumulations using background precipitation estimates from the GEOS-5 atmospheric data assimilation system. Depending on the specific combination of the observational precipitation product and the GEOS-5 background estimates, the observational product may also be downscaled in space. The resulting corrected precipitation data product is at the finer temporal and spatial resolution of the GEOS-5 background and matches the observed precipitation at the coarser scale of the observational product, separately for each day (or pentad) and each grid cell.
Nuclear physics for geo-neutrino studies
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fiorentini, Gianni; Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, I-44100 Ferrara; Ianni, Aldo
2010-03-15
Geo-neutrino studies are based on theoretical estimates of geo-neutrino spectra. We propose a method for a direct measurement of the energy distribution of antineutrinos from decays of long-lived radioactive isotopes. We present preliminary results for the geo-neutrinos from {sup 214}Bi decay, a process that accounts for about one-half of the total geo-neutrino signal. The feeding probability of the lowest state of {sup 214}Bi--the most important for geo-neutrino signal--is found to be p{sub 0}=0.177+-0.004 (stat){sub -0.001}{sup +0.003} (sys), under the hypothesis of universal neutrino spectrum shape (UNSS). This value is consistent with the (indirect) estimate of the table of isotopes. Wemore » show that achievable larger statistics and reduction of systematics should allow for the testing of possible distortions of the neutrino spectrum from that predicted using the UNSS hypothesis. Implications on the geo-neutrino signal are discussed.« less
Determining sea-ice boundaries and ice roughness using GEOS-3 altimeter data
NASA Technical Reports Server (NTRS)
Dwyer, R. E.; Godin, R. H.
1980-01-01
The GEOS-3 satellite and radar altimeter instrumentation are described, detailing the ice boundary discrimination technique utilized and presenting an analyses of the GEOS-3 data with respect to satellite visual and IR imagery. A brief description of the GEOS-3 real time data system is also given.
King County Nearshore Habitat Mapping Data Report: Picnic Point to Shilshole Bay Marina
DOE Office of Scientific and Technical Information (OSTI.GOV)
Woodruff, Dana L.; Farley, Paul J.; Borde, Amy B.
2000-12-31
The objective of this study is to provide accurate, georeferenced maps of benthic habitats to assist in the siting of a new wastewater treatment plant outfall and the assessment of habitats of endangered, threatened, and economically important species. The mapping was conducted in the fall of 1999 using two complementary techniques: side-scan sonar and underwater videography. Products derived from these techniques include geographic information system (GIS) compatible polygon data of substrate type and vegetation cover, including eelgrass and kelp. Additional GIS overlays include underwater video track line data of total macroalgae, selected macroalgal species, fish, and macroinvertebrates. The combined toolsmore » of geo-referenced side-scan sonar and underwater video is a powerful technique for assessing and mapping of nearshore habitat in Puget Sound. Side-scan sonar offers the ability to map eelgrass with high spatial accuracy and resolution, and provides information on patch size, shape, and coverage. It also provides information on substrate change and location of specific targets (e.g., piers, docks, pilings, large boulders, debris piles). The addition of underwater video is a complementary tool providing both groundtruthing for the sonar and additional information on macro fauna and flora. As a groundtruthing technique, the video was able to confirm differences between substrate types, as well as detect subtle spatial changes in substrate. It also verified information related to eelgrass, including the density classification categories and the type of substrate associated with eelgrass, which could not be determined easily with side- scan sonar. Video is also a powerful tool for mapping the location of macroalgae, (including kelp and Ulva), fish and macroinvertebrates. The ability to geo-locate these resources in their functional habitat provides an added layer of information and analytical potential.« less
Integrated Geo Hazard Management System in Cloud Computing Technology
NASA Astrophysics Data System (ADS)
Hanifah, M. I. M.; Omar, R. C.; Khalid, N. H. N.; Ismail, A.; Mustapha, I. S.; Baharuddin, I. N. Z.; Roslan, R.; Zalam, W. M. Z.
2016-11-01
Geo hazard can result in reducing of environmental health and huge economic losses especially in mountainous area. In order to mitigate geo-hazard effectively, cloud computer technology are introduce for managing geo hazard database. Cloud computing technology and it services capable to provide stakeholder's with geo hazards information in near to real time for an effective environmental management and decision-making. UNITEN Integrated Geo Hazard Management System consist of the network management and operation to monitor geo-hazard disaster especially landslide in our study area at Kelantan River Basin and boundary between Hulu Kelantan and Hulu Terengganu. The system will provide easily manage flexible measuring system with data management operates autonomously and can be controlled by commands to collects and controls remotely by using “cloud” system computing. This paper aims to document the above relationship by identifying the special features and needs associated with effective geohazard database management using “cloud system”. This system later will use as part of the development activities and result in minimizing the frequency of the geo-hazard and risk at that research area.
NASA Astrophysics Data System (ADS)
Yılmaz, Umit C.; Cavdar, Ismail H.
2015-04-01
In intersatellite optical communication, the Pointing, Acquisition and Tracking (PAT) phase is one of the important phases that needs to be completed successfully before initiating communication. In this paper, we focused on correcting the possible errors on the Geostationary Earth Orbit (GEO) by using azimuth and elevation errors between Low Earth Orbit (LEO) to GEO optical link during the PAT phase. To minimise the PAT duration, a simplified correction of longitude and inclination errors of the GEO satellite's osculating Keplerian parameters has been suggested. A simulation has been done considering the beaconless tracking and spiral-scanning technique. As a result, starting from the second day, we are able to reduce the uncertainty cone of the GEO satellite by about 200 μrad, if the values are larger than that quantity. The first day of the LEO-GEO links have been used to determine the parameters. Thanks to the corrections, the locking time onto the GEO satellite has been reduced, and more data are able to transmit to the GEO satellite.
Facilitating dynamo action via control of large-scale turbulence.
Limone, A; Hatch, D R; Forest, C B; Jenko, F
2012-12-01
The magnetohydrodynamic dynamo effect is considered to be the major cause of magnetic field generation in geo- and astrophysical systems. Recent experimental and numerical results show that turbulence constitutes an obstacle to dynamos; yet its role in this context is not totally clear. Via numerical simulations, we identify large-scale turbulent vortices with a detrimental effect on the amplification of the magnetic field in a geometry of experimental interest and propose a strategy for facilitating the dynamo instability by manipulating these detrimental "hidden" dynamics.
Joshi, Ashish; de Araujo Novaes, Magdala; Machiavelli, Josiane; Iyengar, Sriram; Vogler, Robert; Johnson, Craig; Zhang, Jiajie; Hsu, Chiehwen E
2012-01-01
Public health data is typically organized by geospatial unit. GeoVisualization (GeoVis) allows users to see information visually on a map. Examine telehealth users' perceptions towards existing public health GeoVis applications and obtains users' feedback about features important for the design and development of Human Centered GeoVis application "the SanaViz". We employed a cross sectional study design using mixed methods approach for this pilot study. Twenty users involved with the NUTES telehealth center at Federal University of Pernambuco (UFPE), Recife, Brazil were enrolled. Open and closed ended questionnaires were used to gather data. We performed audio recording for the interviews. Information gathered included socio-demographics, prior spatial skills and perception towards use of GeoVis to evaluate telehealth services. Card sorting and sketching methods were employed. Univariate analysis was performed for the continuous and categorical variables. Qualitative analysis was performed for open ended questions. Existing Public Health GeoVis applications were difficult to use. Results found interaction features zooming, linking and brushing and representation features Google maps, tables and bar chart as most preferred GeoVis features. Early involvement of users is essential to identify features necessary to be part of the human centered GeoVis application "the SanaViz".
NASA Astrophysics Data System (ADS)
Montereale Gavazzi, G.; Madricardo, F.; Janowski, L.; Kruss, A.; Blondel, P.; Sigovini, M.; Foglini, F.
2016-03-01
Recent technological developments of multibeam echosounder systems (MBES) allow mapping of benthic habitats with unprecedented detail. MBES can now be employed in extremely shallow waters, challenging data acquisition (as these instruments were often designed for deeper waters) and data interpretation (honed on datasets with resolution sometimes orders of magnitude lower). With extremely high-resolution bathymetry and co-located backscatter data, it is now possible to map the spatial distribution of fine scale benthic habitats, even identifying the acoustic signatures of single sponges. In this context, it is necessary to understand which of the commonly used segmentation methods is best suited to account for such level of detail. At the same time, new sampling protocols for precisely geo-referenced ground truth data need to be developed to validate the benthic environmental classification. This study focuses on a dataset collected in a shallow (2-10 m deep) tidal channel of the Lagoon of Venice, Italy. Using 0.05-m and 0.2-m raster grids, we compared a range of classifications, both pixel-based and object-based approaches, including manual, Maximum Likelihood Classifier, Jenks Optimization clustering, textural analysis and Object Based Image Analysis. Through a comprehensive and accurately geo-referenced ground truth dataset, we were able to identify five different classes of the substrate composition, including sponges, mixed submerged aquatic vegetation, mixed detritic bottom (fine and coarse) and unconsolidated bare sediment. We computed estimates of accuracy (namely Overall, User, Producer Accuracies and the Kappa statistic) by cross tabulating predicted and reference instances. Overall, pixel based segmentations produced the highest accuracies and the accuracy assessment is strongly dependent on the number of classes chosen for the thematic output. Tidal channels in the Venice Lagoon are extremely important in terms of habitats and sediment distribution, particularly within the context of the new tidal barrier being built. However, they had remained largely unexplored until now, because of the surveying challenges. The application of this remote sensing approach, combined with targeted sampling, opens a new perspective in the monitoring of benthic habitats in view of a knowledge-based management of natural resources in shallow coastal areas.
NASA Astrophysics Data System (ADS)
Salvi, Stefano
2016-04-01
The Geohazard Supersites and Natural Laboratories initiative began with the "Frascati declaration" at the conclusion of the 3rd International Geohazards workshop of GEO held in November 2007 in Frascati, Italy. The recommendation of the workshop was "to stimulate an international and intergovernmental effort to monitor and study selected reference sites by establishing open access to relevant datasets according to GEO principles, to foster the collaboration between all various partners and end-users". This recommendation was later formalized in the GEO Work Plan as Component 2 of the GEO task DI-01, part of the GEO Disasters Societal Benefit Area. Today GSNL has grown to a voluntary collaboration among monitoring agencies, scientific community and the CEOS space agencies, working to improve the scientific understanding of earthquake and volcanic phenomena and enable better risk assessment and emergency management. According to its principles, actions in GSNL are focused on specific areas of the world, the Supersites, for which large amounts of in situ and satellite data are made openly available to all scientists. These areas are selected based on the importance of the scientific problems, as well as on the amount of population at risk, and should be evenly distributed among developed and less developed countries. Seven Supersites have been established to date, six of which on volcanic areas (Hawaii, US; Icelandic volcanoes; Mt. Etna, IT; Campi Flegrei, IT; Ecuadorian volcanoes, Taupo, NZ), and one on a seismic area (Western North Anatolian fault, TR). One more proposals is being evaluated: the Corinth Gulf in Greece. The Supersites have succeeded in promoting new scientific developments by providing a framework for an easier access to EO and in situ data. Coordination among researchers at the global scale has been achieved only where the Supersite activities were sustained through well established projects. For some Supersites a close coordination between scientists and end-users has been established or consolidated, and the clear advantages arising from such collaboration has stimulated a new vision for the GSNL initiative (GSNL 2.0). The status of the initiative and the future developments of GSNL 2.0, aiming to increase the uptake of the Supersite geohazard science by local end-users, will be presented at the meeting and discussed with the scientific community.
Shadow imaging of geosynchronous satellites
NASA Astrophysics Data System (ADS)
Douglas, Dennis Michael
Geosynchronous (GEO) satellites are essential for modern communication networks. If communication to a GEO satellite is lost and a malfunction occurs upon orbit insertion such as a solar panel not deploying there is no direct way to observe it from Earth. Due to the GEO orbit distance of ~36,000 km from Earth's surface, the Rayleigh criteria dictates that a 14 m telescope is required to conventionally image a satellite with spatial resolution down to 1 m using visible light. Furthermore, a telescope larger than 30 m is required under ideal conditions to obtain spatial resolution down to 0.4 m. This dissertation evaluates a method for obtaining high spatial resolution images of GEO satellites from an Earth based system by measuring the irradiance distribution on the ground resulting from the occultation of the satellite passing in front of a star. The representative size of a GEO satellite combined with the orbital distance results in the ground shadow being consistent with a Fresnel diffraction pattern when observed at visible wavelengths. A measurement of the ground shadow irradiance is used as an amplitude constraint in a Gerchberg-Saxton phase retrieval algorithm that produces a reconstruction of the satellite's 2D transmission function which is analogous to a reverse contrast image of the satellite. The advantage of shadow imaging is that a terrestrial based redundant set of linearly distributed inexpensive small telescopes, each coupled to high speed detectors, is a more effective resolved imaging system for GEO satellites than a very large telescope under ideal conditions. Modeling and simulation efforts indicate sub-meter spatial resolution can be readily achieved using collection apertures of less than 1 meter in diameter. A mathematical basis is established for the treatment of the physical phenomena involved in the shadow imaging process. This includes the source star brightness and angular extent, and the diffraction of starlight from the satellite. Atmospheric effects including signal attenuation, refraction/dispersion, and turbulence are also applied to the model. The light collection and physical measurement process using highly sensitive geiger-mode avalanche photo-diode (GM-APD) detectors is described in detail. A simulation of the end-to-end shadow imaging process is constructed and then utilized to quantify the spatial resolution limits based on source star, environmental, observational, collection, measurement, and image reconstruction parameters.
A Modern Explorer's Journey - using events for innovative multipurpose educational outreach
NASA Astrophysics Data System (ADS)
Lilja Bye, Bente
2014-05-01
Earth observations are important across the specter of geo-sciences. The Group on Earth Observations (GEO) is coordinating efforts to build a Global Earth Observation System of Systems, or GEOSS. The lack of dedicated funding to support specific Science &Technology activities in support of GEOSS is one of the most important obstacles to engaging the Science &Technology communities in its implementation. Finding resources to outreach and capacity building is likewise a challenge. The continuation of GEO and GEOSS rely on political support which again is influenced by public opinions. The GEO Ministerial Summit in 2014 was an event that both needed visibility and represented an opportunity to mobilize the GEO community in producing outreach and educational material. Through the combined resources from two of GEO tasks in the GEO work plan, a multipurpose educational outreach project was planned and executed. This project addressed the following issues: How can the GEO community mobilize resources for its work plan projects in the Societal Benefit Area Water? How can we produce more educational and capacity building material? How can the GEO community support the GEO secretariat related to public relations (material and otherwise) Based on activities described in the GEO work plan, a showcase video and online campaign consisting on a series of webinars were developed and produced. The video and webinars were linked through a common reference: the water cycle. Various aspects of the water cycle ranging from general to more technical and scientific education were covered in the webinars, while the video called A Modern Explorer's Journey focused on story telling with a more emotional appeal. The video was presented to the Ministers at the GEO Ministerial Summit and distributed widely to the GEO community and through social media and articles (as embedded YouTube and more). A discussion of challenges and successes of this event-based educational outreach project will be presented. Continued use of new outreach tools such as web technology and social innovations for more efficient use of limited resources will remain an issue for the scientific community. Lessons learned need to be provided continuously and this project add to this material.
NASA Astrophysics Data System (ADS)
Dragozi, E.; Gitas, Ioannis Z.; Stavrakoudis, Dimitris G.; Minakou, C.
2015-06-01
Forest fires greatly influence the stability and functions of the forest ecosystems. The ever increasing need for accurate and detailed information regarding post-fire effects (burn severity) has led to several studies on the matter. In this study the combined use of Very High Resolution (VHR) satellite data (GeoEye), Objectbased image analysis (OBIA) and Composite Burn Index (CBI) measurements in estimating burn severity, at two different time points (2011 and 2012) is assessed. The accuracy of the produced maps was assessed and changes in burn severity between the two dates were detected using the post classification comparison approach. It was found that the produced burn severity map for 2011 was approximately 10% more accurate than that of 2012. This was mainly attributed to the increased heterogeneity of the study area in the second year, which led to an increased number of mixed class objects and consequently made it more difficult to spectrally discriminate between the severity classes. Following the post-classification analysis, the severity class changes were mainly attributed to the trees' ability to survive severe fire damage and sprout new leaves. Moreover, the results of the study suggest that when classifying CBI-based burn severity using VHR imagery it would be preferable to use images captured soon after the fire.
NASA Astrophysics Data System (ADS)
Haubeck, K.; Prinz, T.
2013-08-01
The use of Unmanned Aerial Vehicles (UAVs) for surveying archaeological sites is becoming more and more common due to their advantages in rapidity of data acquisition, cost-efficiency and flexibility. One possible usage is the documentation and visualization of historic geo-structures and -objects using UAV-attached digital small frame cameras. These monoscopic cameras offer the possibility to obtain close-range aerial photographs, but - under the condition that an accurate nadir-waypoint flight is not possible due to choppy or windy weather conditions - at the same time implicate the problem that two single aerial images not always meet the required overlap to use them for 3D photogrammetric purposes. In this paper, we present an attempt to replace the monoscopic camera with a calibrated low-cost stereo camera that takes two pictures from a slightly different angle at the same time. Our results show that such a geometrically predefined stereo image pair can be used for photogrammetric purposes e.g. the creation of digital terrain models (DTMs) and orthophotos or the 3D extraction of single geo-objects. Because of the limited geometric photobase of the applied stereo camera and the resulting base-height ratio the accuracy of the DTM however directly depends on the UAV flight altitude.
Monitoring Seabirds and Marine Mammals by Georeferenced Aerial Photography
NASA Astrophysics Data System (ADS)
Kemper, G.; Weidauer, A.; Coppack, T.
2016-06-01
The assessment of anthropogenic impacts on the marine environment is challenged by the accessibility, accuracy and validity of biogeographical information. Offshore wind farm projects require large-scale ecological surveys before, during and after construction, in order to assess potential effects on the distribution and abundance of protected species. The robustness of site-specific population estimates depends largely on the extent and design of spatial coverage and the accuracy of the applied census technique. Standard environmental assessment studies in Germany have so far included aerial visual surveys to evaluate potential impacts of offshore wind farms on seabirds and marine mammals. However, low flight altitudes, necessary for the visual classification of species, disturb sensitive bird species and also hold significant safety risks for the observers. Thus, aerial surveys based on high-resolution digital imagery, which can be carried out at higher (safer) flight altitudes (beyond the rotor-swept zone of the wind turbines) have become a mandatory requirement, technically solving the problem of distant-related observation bias. A purpose-assembled imagery system including medium-format cameras in conjunction with a dedicated geo-positioning platform delivers series of orthogonal digital images that meet the current technical requirements of authorities for surveying marine wildlife at a comparatively low cost. At a flight altitude of 425 m, a focal length of 110 mm, implemented forward motion compensation (FMC) and exposure times ranging between 1/1600 and 1/1000 s, the twin-camera system generates high quality 16 bit RGB images with a ground sampling distance (GSD) of 2 cm and an image footprint of 155 x 410 m. The image files are readily transferrable to a GIS environment for further editing, taking overlapping image areas and areas affected by glare into account. The imagery can be routinely screened by the human eye guided by purpose-programmed software to distinguish biological from non-biological signals. Each detected seabird or marine mammal signal is identified to species level or assigned to a species group and automatically saved into a geo-database for subsequent quality assurance, geo-statistical analyses and data export to third-party users. The relative size of a detected object can be accurately measured which provides key information for species-identification. During the development and testing of this system until 2015, more than 40 surveys have produced around 500.000 digital aerial images, of which some were taken in specially protected areas (SPA) of the Baltic Sea and thus include a wide range of relevant species. Here, we present the technical principles of this comparatively new survey approach and discuss the key methodological challenges related to optimizing survey design and workflow in view of the pending regulatory requirements for effective environmental impact assessments.
How can knowledge discovery methods uncover spatio-temporal patterns in environmental data?
NASA Astrophysics Data System (ADS)
Wachowicz, Monica
2000-04-01
This paper proposes the integration of KDD, GVis and STDB as a long-term strategy, which will allow users to apply knowledge discovery methods for uncovering spatio-temporal patterns in environmental data. The main goal is to combine innovative techniques and associated tools for exploring very large environmental data sets in order to arrive at valid, novel, potentially useful, and ultimately understandable spatio-temporal patterns. The GeoInsight approach is described using the principles and key developments in the research domains of KDD, GVis, and STDB. The GeoInsight approach aims at the integration of these research domains in order to provide tools for performing information retrieval, exploration, analysis, and visualization. The result is a knowledge-based design, which involves visual thinking (perceptual-cognitive process) and automated information processing (computer-analytical process).
NASA Technical Reports Server (NTRS)
Colombo, G.; Grossi, M. D.; Arnold, D.
1983-01-01
The effect of reeling operations on the orbital altitude of the tether system and the development of control laws to minimize tether rebound upon payload release were studied. The use of the tether for LEO/GEO payload orbital transfer was also investigated. It was concluded that (1) reeling operations can contribute a significant amount of energy to the orbit of the system and should be considered in orbit calculations and predictions, (2) deployment of payloads, even very large payloads, using tethers is a practical and fully stable operation, (3) tether augmented LEO/GEO transfer operations yield useful payload gains under the practical constraint of fixed size OTV's, and (4) orbit to orbit satellite retrieval is limited by useful revisit times to orbital inclinations of less than forty-five degrees.
Next Generation Grating Spectrometer Sounders for LEO and GEO
NASA Technical Reports Server (NTRS)
Pagano, Thomas S.
2011-01-01
AIRS and MODIS are widely used for weather, climate, composition, carbon cycle, cross-calibration, and applications. The community asking for new capability in the 2020 timeframe, capabilities desired: (1) Hyperspectral UV to LWIR, High Spatial ?1km IFOV (2) Maximize Synergies of Solar Reflected and IR. Synergies with OCO-2. We expect more users and applications of next gen LEO IR Sounder than GEO. These include: weather, climate, GHG monitoring, aviation, disaster response. There is a new direction for imagers and sounders: (1) Separate Vis/NIR/SWIR from MWIR/LWIR instruments reduces technology risk and complexity. (2) Expect Costs to be lower than CrIS & VIIRS Some additional ideas to reduce costs include: (1) minimum set of requirements (2) mini-grating spectrometers. supports constellation for higher revisit (3) new technology to reduce instrument size (large format fpa's) (4) hosted payloads
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
During the months of September and October, 1979, EG and G geoMetrics collected 8866 line miles of high sensitivity airborne radiometric and magnetic data. Data were gathered primarily within the state of Texas, in three 1 x 2 degree NTMS quadrangles. This project is part of the Department of Energy's National Uranium Resource Evaluation Program. All radiometric and magnetic data were fully corrected and interpreted by geoMetrics and are presented as four Volumes (one Volume I and three Volume II's). The quadrangles are dominated by Cretaceous and Tertiary marine sediments. The cretaceous rocks are largely shallow marine sediments of biogenicmore » origin, whereas the Tertiary sequence represents transgressing shelf and slope deposits. No uranium deposits are known in this area (Schnabel, 1955).« less
Chapter 12 - Mapping wildland fuel across large regions for the LANDFIRE Prototype Project
Robert E. Keane; Tracey Frescino; Matthew C. Reeves; Jennifer L. Long
2006-01-01
The Landscape Fire and Resource Management Planning Tools Prototype Project, or LANDFIRE Prototype Project, required that the entire array of wildland fuel characteristics be mapped to provide fire and landscape managers with consistent baseline geo-spatial information to plan projects for hazardous fuel mitigation and to improve public and firefighter safety. Fuel...
Negotiating the Geopolitics of Student Resistance in Global Feminisms Classrooms
ERIC Educational Resources Information Center
Ergun, Emek
2013-01-01
This article discusses the geo-political operations of student resistance in global feminisms classrooms, a topic that is largely ignored in the feminist pedagogies literature, where a generic understanding of the feminist teacher as a white, American and/or Western, and upper-class PhD seems to dominate. Given that the number of minority faculty…
Establishing a Professional Development Network around Dynamic Mathematics Software in England
ERIC Educational Resources Information Center
Lavicza, Zsolt; Hohenwarter, Markus; Jones, Keith; Lu, Allison; Dawes, Mark
2010-01-01
In this paper, we will outline some results of an NCETM (National Centre for Excellence in the Teaching of Mathematics) funded project that aimed to establish a professional development network with an open-source mathematical software--GeoGebra--in England. During the past few years a large international user and developer community has formed…
GeoWorks Considered. Part I: A GUI for the Rest of Us. Part II: Doing Windows Right.
ERIC Educational Resources Information Center
Flanders, Bruce; Lewis, Paul
1991-01-01
Describes GeoWorks, a new graphical user interface (GUI) that works on older, less powerful IBM PCs and compatibles. The PC/GEOS (PC/Graphical Environment Operating System) is explained, user friendliness is emphasized, comparisons are made to Microsoft Windows, and GeoWorks applications software is described. (LRW)
GeoGebra for Mathematical Statistics
ERIC Educational Resources Information Center
Hewson, Paul
2009-01-01
The GeoGebra software is attracting a lot of interest in the mathematical community, consequently there is a wide range of experience and resources to help use this application. This article briefly outlines how GeoGebra will be of great value in statistical education. The release of GeoGebra is an excellent example of the power of free software…
Designing GeoGebra Applets to Maximize Student Engagement
ERIC Educational Resources Information Center
Paoletti, Teo; Monahan, Ceire; Vishnubhotla, Madhavi
2017-01-01
GeoGebra is a free tool that has the potential to change both how and what is taught in mathematics. GeoGebra allows teachers and students to explore various mathematical ideas either through the full applet (https://www.geogebra.org/graphing) or by sharing applets via GeoGebra's Materials site (https://www.geogebra. org/materials/). It has many…
The Intention to Use GeoGebra in the Teaching of Mathematics among Malaysian Teachers
ERIC Educational Resources Information Center
Belgheis, Soheila; Kamalludeen, Rosemaliza
2018-01-01
This quantitative study examined Malaysian teachers' perception towards using GeoGebra in mathematics teaching. The relationship between teachers' Perceived Current Competencies (PCC) of GeoGebra, and Intention to Use (IU) it as well as the difference between male and female teachers and between users and non-users of GeoGebra were investigated.…
The Development of Geo-KOMPSAT-2A (GK-2A) Convective Initiation Algorithm over the Korea peninsular
NASA Astrophysics Data System (ADS)
Kim, H. S.; Chung, S. R.; Lee, B. I.; Baek, S.; Jeon, E.
2016-12-01
The rapid development of convection can bring heavy rainfall that suffers a great deal of damages to society as well as threatens human life. The high accurate forecast of the strong convection is essentially demanded to prevent those disasters from the severe weather. Since a geostationary satellite is the most suitable instrument for monitoring the single cloud's lifecycle from its formation to extinction, it has been attempted to capture the precursor signals of convection clouds by satellite. Keeping pace with the launch of Geo-KOMPSAT-2A (GK-2A) in 2018, we planned to produce convective initiation (CI) defined as the indicator of potential cloud objects to bring heavy precipitation within two hours. The CI algorithm for GK-2A is composed of four stages. The beginning is to subtract mature cloud pixels, a sort of convective cloud mask by visible (VIS) albedo and infrared (IR) brightness temperature thresholds. Then, the remained immature cloud pixels are clustered as a cloud object by watershed techniques. Each clustering object is undergone 'Interest Fields' tests for IR data that reflect cloud microphysical properties at the current and their temporal changes; the cloud depth, updraft strength and production of glaciations. All thresholds of 'Interest fields' were optimized for Korean-type convective clouds. Based on scores from tests, it is decided whether the cloud object would develop as a convective cell or not. Here we show the result of case study in this summer over the Korea peninsular by using Himawari-8 VIS and IR data. Radar echo and data were used for validation. This study suggests that CI products of GK-2A would contribute to enhance accuracy of the very short range forecast over the Korea peninsular.
[Brief introduction of geo-authentic herbs].
Liang, Fei; Li, Jian; Zhang, Wei; Zhang, Rui-Xian
2013-05-01
The science of geo-authentic herbs is a characteristic discipline of traditional Chinese medicine established during thousands of years of clinical practices. It has a long history under the guidance of profound theories of traditional Chinese medicine. The words of "geo-authentic product" were derived from an administrative division unit in the ancient times, which layed stress on the good quality of products in particular regions. In ancient records of traditional Chinese medicine, the words of "geo-authentic product" were first found in Concise Herbal Foundation Compilation of the Ming dynasty, and the words of "geo-authentic herbs" were first discovered in Peony Pavilion of the late Ming dynasty. After all, clinical effect is the fundamental evaluation standard of geo-authentic herbs.
The Correlation of Geo-Ecological Environment and Mountain Urban planning
NASA Astrophysics Data System (ADS)
Yang, Chun; Zeng, Wei
2018-01-01
As a special area with the complex geological structure, mountain city is more prone to geological disasters. Due to air pollution, ground subsidence, serious water pollution, earthquakes and floods geo-ecological environment problems have become increasingly serious, mountain urban planning is facing more severe challenges. Therefore, this article bases on the correlation research of geo-ecological environment and mountain urban planning, and re-examins mountain urban planning from the perspective of geo-ecological, coordinates the relationship between the human and nature by geo-ecological thinking, raises the questions which urban planning need to pay attention. And advocates creating an integrated system of geo-ecological and mountain urban planning, analysis the status and dynamics of present mountain urban planning.
Investigating Geosparql Requirements for Participatory Urban Planning
NASA Astrophysics Data System (ADS)
Mohammadi, E.; Hunter, A. J. S.
2015-06-01
We propose that participatory GIS (PGIS) activities including participatory urban planning can be made more efficient and effective if spatial reasoning rules are integrated with PGIS tools to simplify engagement for public contributors. Spatial reasoning is used to describe relationships between spatial entities. These relationships can be evaluated quantitatively or qualitatively using geometrical algorithms, ontological relations, and topological methods. Semantic web services utilize tools and methods that can facilitate spatial reasoning. GeoSPARQL, introduced by OGC, is a spatial reasoning standard used to make declarations about entities (graphical contributions) that take the form of a subject-predicate-object triple or statement. GeoSPARQL uses three basic methods to infer topological relationships between spatial entities, including: OGC's simple feature topology, RCC8, and the DE-9IM model. While these methods are comprehensive in their ability to define topological relationships between spatial entities, they are often inadequate for defining complex relationships that exist in the spatial realm. Particularly relationships between urban entities, such as those between a bus route, the collection of associated bus stops and their overall surroundings as an urban planning pattern. In this paper we investigate common qualitative spatial reasoning methods as a preliminary step to enhancing the capabilities of GeoSPARQL in an online participatory GIS framework in which reasoning is used to validate plans based on standard patterns that can be found in an efficient/effective urban environment.
Chilean geo client application for disasters
NASA Astrophysics Data System (ADS)
Suárez, Rodrigo F.; Lovison, Lucia; Potters, Martinus
2018-05-01
The global network of the Group on Earth Observation, GEO, connects all kinds of professionals from public and private institutions with data providers, sharing information to face the challenges of global changes and human development and they are creating a Global Earth Observation System of Systems (GEOSS) to connect existing data infrastructures. A GEOSS Architecture Implementation Pilot Project for Disasters in Chile (AIP-8) was created as part of a capacity building initiative and representatives of different national agencies in Chile, along with international experts, formed a GEOSS Capacity Building Working Group (Lovison et al, 2016). Consistent with the objectives of GEOSS AIP-8 Chile, we developed and implemented a prototype service based on web services, mobile applications and other communication channels, which allows connecting different sources of information, aiming to reduce population vulnerability to natural disasters such as: earthquakes, flooding, wild fires and tsunamis, which is presented here. The GEO Chile client application is a JavaScript application using GEODAB brokering services, GIS technology and disaster information provided by national and international disaster services, including public and private organizations, where cartography becomes fundamental as a tool to provide realism and ubiquity to the information. Seven hotpots are targeted: Calbuco, Copahue and Villarrica volcanoes areas, Valparaíso city, which is frequently a victim of wildfires in the zone where population meets forest and Iquique, Illapel and Talcahuano, areas frequently struck by earthquakes and tsunamis.
Radiative Impacts of Cloud Heterogeneity and Overlap in an Atmospheric General Circulation Model
NASA Technical Reports Server (NTRS)
Oreopoulos, L.; Lee, D.; Sud, Y. C.; Suarez, M. J.
2012-01-01
The radiative impacts of introducing horizontal heterogeneity of layer cloud condensate, and vertical overlap of condensate and cloud fraction are examined with the aid of a new radiation package operating in the GEOS-5 Atmospheric General Circulation Model. The impacts are examined in terms of diagnostic top-of-the-atmosphere shortwave (SW) and longwave (LW) cloud radiative effect (CRE) calculations for a range of assumptions and parameter specifications about the overlap. The investigation is conducted for two distinct cloud schemes, the one that comes with the standard GEOS-5 distribution, and another which has been recently used experimentally for its enhanced GEOS-5 distribution, and another which has been recently used experimentally for its enhanced cloud microphysical capabilities; both are coupled to a cloud generator allowing arbitrary cloud overlap specification. We find that cloud overlap radiative impacts are significantly stronger for the operational cloud scheme for which a change of cloud fraction overlap from maximum-random to generalized results to global changes of SW and LW CRE of approximately 4 Watts per square meter, and zonal changes of up to approximately 10 Watts per square meter. This is because of fewer occurrences compared to the other scheme of large layer cloud fractions and of multi-layer situations with large numbers of atmospheric being simultaneously cloudy, conditions that make overlap details more important. The impact on CRE of the details of condensate distribution overlap is much weaker. Once generalized overlap is adopted, both cloud schemes are only modestly sensitive to the exact values of the overlap parameters. We also find that if one of the CRE components is overestimated and the other underestimated, both cannot be driven towards observed values by adjustments to cloud condensate heterogeneity and overlap alone.
Integrating Semantic Information in Metadata Descriptions for a Geoscience-wide Resource Inventory.
NASA Astrophysics Data System (ADS)
Zaslavsky, I.; Richard, S. M.; Gupta, A.; Valentine, D.; Whitenack, T.; Ozyurt, I. B.; Grethe, J. S.; Schachne, A.
2016-12-01
Integrating semantic information into legacy metadata catalogs is a challenging issue and so far has been mostly done on a limited scale. We present experience of CINERGI (Community Inventory of Earthcube Resources for Geoscience Interoperability), an NSF Earthcube Building Block project, in creating a large cross-disciplinary catalog of geoscience information resources to enable cross-domain discovery. The project developed a pipeline for automatically augmenting resource metadata, in particular generating keywords that describe metadata documents harvested from multiple geoscience information repositories or contributed by geoscientists through various channels including surveys and domain resource inventories. The pipeline examines available metadata descriptions using text parsing, vocabulary management and semantic annotation and graph navigation services of GeoSciGraph. GeoSciGraph, in turn, relies on a large cross-domain ontology of geoscience terms, which bridges several independently developed ontologies or taxonomies including SWEET, ENVO, YAGO, GeoSciML, GCMD, SWO, and CHEBI. The ontology content enables automatic extraction of keywords reflecting science domains, equipment used, geospatial features, measured properties, methods, processes, etc. We specifically focus on issues of cross-domain geoscience ontology creation, resolving several types of semantic conflicts among component ontologies or vocabularies, and constructing and managing facets for improved data discovery and navigation. The ontology and keyword generation rules are iteratively improved as pipeline results are presented to data managers for selective manual curation via a CINERGI Annotator user interface. We present lessons learned from applying CINERGI metadata augmentation pipeline to a number of federal agency and academic data registries, in the context of several use cases that require data discovery and integration across multiple earth science data catalogs of varying quality and completeness. The inventory is accessible at http://cinergi.sdsc.edu, and the CINERGI project web page is http://earthcube.org/group/cinergi
NASA Technical Reports Server (NTRS)
1991-01-01
The solar power satellite (SPS) will provide a clean, reliable source of energy for large-scale consumption. The system will use satellites in geostationary orbits around the Earth to capture the Sun's energy. The intercepted sunlight will be converted to laser beam energy that can be transmitted to the Earth's surface. Ground systems on the Earth will convert the transmissions from space into electric power. The preliminary design for the SPS consists of one satellite in orbit around the Earth transmitting energy to a single ground station. The SPS design uses multilayer solar cell technology arranged on a 20 km squared planar array to intercept sunlight and convert it to an electric voltage. Power conditioning devices then send the electricity to a laser, which transmits the power to the surface of the Earth. A ground station will convert the beam into electricity. Typically, a single SPS will supply 5 GW of power to the ground station. Due to the large mass of the SPS, about 41 million kg, construction in space is needed in order to keep the structural mass low. The orbit configuration for this design is to operate a single satellite in geosynchronous orbit (GEO). The GEO allows the system to be positioned above a single receiving station and remain in sunlight 99 percent of the time. Construction will take place in low Earth orbit (LEO); array sections, 20 in total, will be sailed on solar wind out to the GEO location in 150 days. These individual transportation sections are referred to as solar sailing array panels (SSAP's). The primary truss elements used to support the array are composed of composite tubular members in a pentahedral arrangement. Smart segments consisting of passive and active damping devices will increase the control of dynamic SPS modes.
GEO Water Cycle Activities and Plans
NASA Astrophysics Data System (ADS)
Lawford, R.; Koike, T.; Ishida, C.; Grabs, W.
2008-12-01
The Group on Earth Observations (GEO) consists of more than 70 countries and 40 international organizations which are working together to develop the Global Earth Observation System of Systems (GEOSS). Since its launch in 2004, GEO has stimulated a wide range of activities related to data systems and their architecture, the development of science and technology to support observational programs, user interactions and interfaces, and capacity building. GEO tasks directed at Water Resources Management, one of the nine GEO Societal Benefit areas, are an integral part of these developments. They draw heavily upon the activities of the Integrated Global Water Cycle Observations (IGWCO) theme and on the activities and infrastructure provided through GEO and its committees. Within the GEO framework the water related activities have been focused on four specific tasks namely integrated data set development; information for floods, droughts and water management; water quality, and capacity building. Currently these efforts are being facilitated by the IGWCO theme that was formed under the former Integrated Global Observing Strategy Partnership (IGOS-P). With the dissolution of this partnership, other mechanisms, including the GEO Water Cycle Community of Practice, are being considered as new opportunitites for coordinating the work of the theme and the water-related GEO tasks. This talk provides a description of the GEO water tasks and reviews the progress that has been made in addressing them. It also provides a perspective on new opportunities and briefly describes some of the mechanisms, such as the Water Cycle Community of Practice, that could be expanded to coordinate a more comprehensive set of water tasks and greater community involvement.
Application of CCD drift-scan photoelectric technique on monitoring GEO satellites
NASA Astrophysics Data System (ADS)
Yu, Yong; Zhao, Xiao-Fen; Luo, Hao; Mao, Yin-Dun; Tang, Zheng-Hong
2018-05-01
Geosynchronous Earth Orbit (GEO) satellites are widely used because of their unique characteristics of high-orbit and remaining permanently in the same area of the sky. Precise monitoring of GEO satellites can provide a key reference for the judgment of satellite operation status, the capture and identification of targets, and the analysis of collision warning. The observation using ground-based optical telescopes plays an important role in the field of monitoring GEO targets. Different from distant celestial bodies, there is a relative movement between the GEO target and the background reference stars, which makes the conventional observation method limited for long focal length telescopes. CCD drift-scan photoelectric technique is applied on monitoring GEO targets. In the case of parking the telescope, the good round images of the background reference stars and the GEO target at the same sky region can be obtained through the alternating observation of CCD drift-scan mode and CCD stare mode, so as to improve the precision of celestial positioning for the GEO target. Observation experiments of GEO targets were carried out with 1.56-meter telescope of Shanghai Astronomical Observatory. The results show that the application of CCD drift-scan photoelectric technique makes the precision of observing the GEO target reach the level of 0.2″, which gives full play to the advantage of the long focal length of the telescope. The effect of orbit improvement based on multi-pass of observations is obvious and the prediction precision of extrapolating to 72-h is in the order of several arc seconds in azimuth and elevation.
NASA Astrophysics Data System (ADS)
Favali, Paolo; Beranzoli, Laura; Best, Mairi; Franceschini, PierLuigi; Materia, Paola; Peppoloni, Silvia; Picard, John
2014-05-01
EMSO (European Multidisciplinary Seafloor and Water Column Observatory) is a large-scale European Research Infrastructure (RI). It is a geographically distributed infrastructure composed of several deep-seafloor and water-column observatories, which will be deployed at key sites in European waters, spanning from the Arctic, through the Atlantic and Mediterranean, to the Black Sea, with the basic scientific objective of real-time, long-term monitoring of environmental processes related to the interaction between the geosphere, biosphere and hydrosphere. EMSO is one of the environmental RIs on the ESFRI roadmap. The ESRFI Roadmap identifies new RIs of pan-European importance that correspond to the long term needs of European research communities. EMSO will be the sub-sea segment of the EU's large-scale Earth Observation program, Copernicus (previously known as GMES - Global Monitoring for Environment and Security) and will significantly enhance the observational capabilities of European member states. An open data policy compliant with the recommendations being developed within the GEOSS initiative (Global Earth Observation System of Systems) will allow for shared use of the infrastructure and the exchange of scientific information and knowledge. The processes that occur in the oceans have a direct impact on human societies, therefore it is crucial to improve our understanding of how they operate and interact. To encompass the breadth of these major processes, sustained and integrated observations are required that appreciate the interconnectedness of atmospheric, surface ocean, biological pump, deep-sea, and solid-Earth dynamics and that can address: • natural and anthropogenic change; • interactions between ecosystem services, biodiversity, biogeochemistry, physics, and climate; • impacts of exploration and extraction of energy, minerals, and living resources; • geo-hazard early warning capability for earthquakes, tsunamis, gas-hydrate release, and slope instability and failure; • connecting scientific outcomes to stakeholders and policy makers, including to government decision-makers. The development of a large research infrastructure initiatives like EMSO must continuously take into account wide-reaching environmental and socio-economic implications and objectives. For this reason, an Ethics Commitee was established early in EMSO's initial Preparatory Phase with responsibility for overseeing the key ethical and social aspects of the project. These include: • promoting inclusive science communication and data dissemination services to civil society according to Open Access principles; • guaranteeing top quality scientific information and data as results of top quality research; • promoting the increased adoption of eco-friendly, sustainable technologies through the dissemination of advanced scientific knowledge and best practices to the private sector and to policy makers; • developing Education Strategies in cooperation with academia and industry aimed at informing and sensitizing the general public on the environmental and socio-economic implications and benefits of large research infrastructure initiatives such as EMSO; • carrying out Excellent Science following strict criteria of research integrity, as expressed in the Montreal Statement (2013); • promoting Geo-ethical awareness and innovation by spurring innovative approaches in the management of environmental aspects of large research projects; • supporting technological Innovation by working closely in support of SMEs; • providing a constant, qualified and authoritative one-stop-shopping Reference Point and Advisory for politicians and decision-makers. The paper shows how Geoethics is an essential tool for guiding methodological and operational choices, and management of an European project with great impact on the environment and society.
Towards Complete, Geo-Referenced 3d Models from Crowd-Sourced Amateur Images
NASA Astrophysics Data System (ADS)
Hartmann, W.; Havlena, M.; Schindler, K.
2016-06-01
Despite a lot of recent research, photogrammetric reconstruction from crowd-sourced imagery is plagued by a number of recurrent problems. (i) The resulting models are chronically incomplete, because even touristic landmarks are photographed mostly from a few "canonical" viewpoints. (ii) Man-made constructions tend to exhibit repetitive structure and rotational symmetries, which lead to gross errors in the 3D reconstruction and aggravate the problem of incomplete reconstruction. (iii) The models are normally not geo-referenced. In this paper, we investigate the possibility of using sparse GNSS geo-tags from digital cameras to address these issues and push the boundaries of crowd-sourced photogrammetry. A small proportion of the images in Internet collections (≍ 10 %) do possess geo-tags. While the individual geo-tags are very inaccurate, they nevertheless can help to address the problems above. By providing approximate geo-reference for partial reconstructions they make it possible to fuse those pieces into more complete models; the capability to fuse partial reconstruction opens up the possibility to be more restrictive in the matching phase and avoid errors due to repetitive structure; and collectively, the redundant set of low-quality geo-tags can provide reasonably accurate absolute geo-reference. We show that even few, noisy geo-tags can help to improve architectural models, compared to puristic structure-from-motion only based on image correspondence.
Air Quality Side Event Proposal November 2016 GEO XIII ...
The Group on Earth Observations (GEO), which EPA has participated in since 2003, has put out a call for Side Events for its thirteenth annual international Plenary Meeting which is in St. Petersburg, Russia this year during November, 2016. EPA has put on Side Events on Air Quality and Health observational systems at eight of the previous Plenaries. This document is a Side Event proposal regarding air quality, health and next generation monitoring and observations techniques. It is submitted to the GEO Secretariat for consideration. If accepted, there will likely be presentations by EPA and NASA, other GEO Member Countries and UNEP and other GEO Participating Organizations at the Side Event. It is an opportunity to share scientific and technological advances in this area and build partnerships and collaboration. The Group on Earth Observations (GEO), which EPA has participated in since 2003, has put out a call for Side Events for its thirteenth annual international Plenary Meeting which is in St. Petersburg, Russia this year during November, 2016. EPA has put on Side Events on Air Quality and Health observational systems at eight of the previous Plenaries. This document is a Side Event proposal regarding air quality, health and next generation monitoring and observations techniques. It is submitted to the GEO Secretariat for consideration. If accepted, there will likely be presentations by EPA and NASA, other GEO Member Countries and UNEP and other GEO P
Framework 'interstitial' oxygen in La(10)(GeO(4))(5-)(GeO(5))O(2) apatite electrolyte.
Pramana, Stevin S; Klooster, Wim T; White, T J
2007-08-01
Oxygen conduction at low temperatures in apatites make these materials potentially useful as electrolytes in solid-oxide fuel cells, but our understanding of the defect structures enabling ion migration is incomplete. While conduction along [001] channels is dominant, considerable inter-tunnel mobility has been recognized. Using neutron powder diffraction of stoichiometric 'La(10)(GeO(4))(6)O(3)', it has been shown that this compound is more correctly described as an La(10)(GeO(4))(5-)(GeO(5))O(2) apatite, in which high concentrations of interstitial oxygen reside within the channel walls. It is suggested that these framework interstitial O atoms provide a reservoir of ions that can migrate into the conducting channels of apatite, via a mechanism of inter-tunnel oxygen diffusion that transiently converts GeO(4) tetrahedra to GeO(5) distorted trigonal bipyramids. This structural modification is consistent with known crystal chemistry and may occur generally in oxide apatites.
NCBI GEO: archive for high-throughput functional genomic data.
Barrett, Tanya; Troup, Dennis B; Wilhite, Stephen E; Ledoux, Pierre; Rudnev, Dmitry; Evangelista, Carlos; Kim, Irene F; Soboleva, Alexandra; Tomashevsky, Maxim; Marshall, Kimberly A; Phillippy, Katherine H; Sherman, Patti M; Muertter, Rolf N; Edgar, Ron
2009-01-01
The Gene Expression Omnibus (GEO) at the National Center for Biotechnology Information (NCBI) is the largest public repository for high-throughput gene expression data. Additionally, GEO hosts other categories of high-throughput functional genomic data, including those that examine genome copy number variations, chromatin structure, methylation status and transcription factor binding. These data are generated by the research community using high-throughput technologies like microarrays and, more recently, next-generation sequencing. The database has a flexible infrastructure that can capture fully annotated raw and processed data, enabling compliance with major community-derived scientific reporting standards such as 'Minimum Information About a Microarray Experiment' (MIAME). In addition to serving as a centralized data storage hub, GEO offers many tools and features that allow users to effectively explore, analyze and download expression data from both gene-centric and experiment-centric perspectives. This article summarizes the GEO repository structure, content and operating procedures, as well as recently introduced data mining features. GEO is freely accessible at http://www.ncbi.nlm.nih.gov/geo/.
New NASA SEE LEO Spacecraft Charging Design Guidelines: How to Survive in LEO Rather Than GEO
NASA Technical Reports Server (NTRS)
Ferguson, Dale C.; Hillard, G. Barry
2003-01-01
It has been almost two solar cycles since the 1984 GEO Guidelines of Purvis, Garrett, Whittlesey, and Stevens were published. In that time, interest in high voltage LEO systems has increased. Correct and conventional wisdom has been that LEO conditions are sufficiently different from GEO that the GEO Guidelines (and other GEO and POLAR documents produced since then) should not be used for LEO spacecraft. Because of significant recent GEO spacecraft failures that have been shown in ground testing to be likely to also occur on LEO spacecraft, the SEE program commissioned the production of the new LEO Spacecraft Charging Design Guidelines. Now available in CD-ROM form, the LEO Guidelines highlight mitigation techniques to prevent spacecraft arcing on LEO solar arrays and other systems. We compare and contrast the mitigation techniques for LEO and GEO in this paper. We also discuss the extensive bibliography included in the LEO Guidelines, so results can be found in their primary sources.