Science.gov

Sample records for activities include ground-based

  1. Space life sciences: ground-based iron-ion biology and physics, including shielding.

    PubMed

    2005-01-01

    This session of the 35th Scientific Assembly of COSPAR focuses on recent advances in ground-based studies of high-energy (mainly 1 GeV/nucleon) iron ions. The theme is interdisciplinary in nature and encompasses both physics and biology reports. Manned space missions, including those of the International Space Station and the planned Mars mission, will require the extended presence of crew members in space. As such, a better understanding in shielding design--in radiation detection as well as radio-protection based on simulating studies--is much needed. On the other hand, a better understanding of the basic mechanisms that modulate radiation sensitivity; in determining DNA double strand breaks, chromosomal aberrations, and the induction of apoptosis, will provide important information for an interventional approach. PMID:15929229

  2. Ground-based activities in preparation of SELENE ISS experiment on self-rewetting fluids

    NASA Astrophysics Data System (ADS)

    Savino, R.; Abe, Y.; Castagnolo, D.; Celata, G. P.; Kabov, O.; Kawaji, M.; Sato, M.; Tanaka, K.; Thome, J. R.; Van Vaerenbergh, S.

    2011-12-01

    SELENE (SELf rewetting fluids for thermal ENErgy management) is a microgravity experiment proposed to the European Space Agency (ESA) in response to the Announcement of Opportunities for Physical Sciences. Main objectives of the microgravity research onboard ISS include the quantitative investigation of heat transfer performances of "self-rewetting fluids" and "nano self-rewetting fluids" in model heat pipes and validation of adequate theoretical and numerical modelling able to predict their behaviour in microgravity conditions. This article summarizes the results of ground-based research activities in preparation of the microgravity experiments. They include: 1) thermophysical properties measurements; 2) study of thermo-soluto-capillary effects in micro-channels; 3) numerical modelling; 4) thermal and concentration distribution measurements with optical (e.g. interferometric) and intrusive techniques; 5) surface tension-driven effects and thermal performances test on different capillary structures and heat pipes; 6) breadboards development and support to definition of scientific requirements.

  3. Characterization of Activity at Loki from Galileo and Ground-based Observations

    NASA Technical Reports Server (NTRS)

    Howell, R. R.; Lopes, R. M.

    2004-01-01

    While Loki is the most active volcanic center on Io, major questions remain concerning the nature of that activity. Rathbun et al. showed that the activity was semi-periodic, and suggested it was due to a resurfacing wave which swept across a lava lake as the crust cooled and become unstable. However in 2001 new observations showed that an intermediate level, less periodic mode of activity had apparently begun. Galileo-NIMS observations of Loki clearly show that the highest temperatures are found near the edge of the patera, consistent with disruption of a lava lake at the margins. NIMS observations also show gradients in temperature across the patera which, when modeled in terms of lava cooling models, are generally consistent with ages expected for the resurfacing wave but may also be consistent with spreading flows. We present a further analysis of NIMS data from I24 and I32 which help define the nature of the temperature variations present in Loki patera, along with Galileo-SSI images from the G1-I32 flybys which show albedo changes apparently correlated with the "periodic" activity measured from ground-based observations.

  4. Study of Droplet Activation in Thin Clouds Using Ground-based Raman Lidar and Ancillary Remote Sensors

    NASA Astrophysics Data System (ADS)

    Rosoldi, Marco; Madonna, Fabio; Gumà Claramunt, Pilar; Pappalardo, Gelsomina

    2015-04-01

    Studies on global climate change show that the effects of aerosol-cloud interactions (ACI) on the Earth's radiation balance and climate, also known as indirect aerosol effects, are the most uncertain among all the effects involving the atmospheric constituents and processes (Stocker et al., IPCC, 2013). Droplet activation is the most important and challenging process in the understanding of ACI. It represents the direct microphysical link between aerosols and clouds and it is probably the largest source of uncertainty in estimating indirect aerosol effects. An accurate estimation of aerosol-clouds microphysical and optical properties in proximity and within the cloud boundaries represents a good frame for the study of droplet activation. This can be obtained by using ground-based profiling remote sensing techniques. In this work, a methodology for the experimental investigation of droplet activation, based on ground-based multi-wavelength Raman lidar and Doppler radar technique, is presented. The study is focused on the observation of thin liquid water clouds, which are low or midlevel super-cooled clouds characterized by a liquid water path (LWP) lower than about 100 gm-2(Turner et al., 2007). These clouds are often optically thin, which means that ground-based Raman lidar allows the detection of the cloud top and of the cloud structure above. Broken clouds are primarily inspected to take advantage of their discontinuous structure using ground based remote sensing. Observations are performed simultaneously with multi-wavelength Raman lidars, a cloud Doppler radar and a microwave radiometer at CIAO (CNR-IMAA Atmospheric Observatory: www.ciao.imaa.cnr.it), in Potenza, Southern Italy (40.60N, 15.72E, 760 m a.s.l.). A statistical study of the variability of optical properties and humidity in the transition from cloudy regions to cloud-free regions surrounding the clouds leads to the identification of threshold values for the optical properties, enabling the

  5. Study of Droplet Activation in Thin Clouds Using Ground-Based Raman Lidar and Ancillary Remote Sensors

    NASA Astrophysics Data System (ADS)

    Rosoldi, Marco; Madonna, Fabio; Gumà Claramunt, Pilar; Pappalardo, Gelsomina

    2016-06-01

    A methodology for the study of cloud droplet activation based on the measurements performed with ground-based multi-wavelength Raman lidars and ancillary remote sensors collected at CNR-IMAA observatory, Potenza, South Italy, is presented. The study is focused on the observation of thin warm clouds. Thin clouds are often also optically thin: this allows the cloud top detection and the full profiling of cloud layers using ground-based Raman lidar. Moreover, broken clouds are inspected to take advantage of their discontinuous structure in order to study the variability of optical properties and water vapor content in the transition from cloudy regions to cloudless regions close to the cloud boundaries. A statistical study of this variability leads to identify threshold values for the optical properties, enabling the discrimination between clouds and cloudless regions. These values can be used to evaluate and improve parameterizations of droplet activation within numerical models. A statistical study of the co-located Doppler radar moments allows to retrieve droplet size and vertical velocities close to the cloud base. First evidences of a correlation between droplet vertical velocities measured at the cloud base and the aerosol effective radius observed in the cloud-free regions of the broken clouds are found.

  6. Continuous Water Vapor Profiles from Operational Ground-Based Active and Passive Remote Sensors

    NASA Technical Reports Server (NTRS)

    Turner, D. D.; Feltz, W. F.; Ferrare, R. A.

    2000-01-01

    The Atmospheric Radiation Measurement program's Southern Great Plains Cloud and Radiation Testbed site central facility near Lamont, Oklahoma, offers unique operational water vapor profiling capabilities, including active and passive remote sensors as well as traditional in situ radiosonde measurements. Remote sensing technologies include an automated Raman lidar and an automated Atmospheric Emitted Radiance Interferometer (AERI), which are able to retrieve water vapor profiles operationally through the lower troposphere throughout the diurnal cycle. Comparisons of these two water vapor remote sensing methods to each other and to radiosondes over an 8-month period are presented and discussed, highlighting the accuracy and limitations of each method. Additionally, the AERI is able to retrieve profiles of temperature while the Raman lidar is able to retrieve aerosol extinction profiles operationally. These data, coupled with hourly wind profiles from a 915-MHz wind profiler, provide complete specification of the state of the atmosphere in noncloudy skies. Several case studies illustrate the utility of these high temporal resolution measurements in the characterization of mesoscale features within a 3-day time period in which passage of a dryline, warm air advection, and cold front occurred.

  7. Ozone treatment of coal- and coffee grounds-based active carbons: Water vapor adsorption and surface fractal micropores

    SciTech Connect

    Tsunoda, Ryoichi; Ozawa, Takayoshi; Ando, Junichi

    1998-09-15

    Characteristics of the adsorption iostherms of water vapor on active carbons from coal and coffee grounds and those ozonized ones from the surface fractal dimension analysis are discussed. The upswing of the adsorption isotherms in the low relative pressure of coffee grounds-based active carbon, of which isotherms were not scarcely affected on ozonization, was attributed to the adsorption of water molecules on the metallic oxides playing the role of oxygen-surface complexes, which formed the corrugated surfaces on the basal planes of micropore walls with the surface fractal dimension D{sub s} > 2. On the other hand, coal-based active carbon with D{sub s} < 2, which indicated the flat surfaces of micropore walls, showed little effect on the upswing even on ozonization, even though the adsorption amounts of water vapor were increased in the low relative pressure.

  8. SO2 on Venus: IUE, HST and ground-based measurements, and the active volcanism connection

    NASA Technical Reports Server (NTRS)

    Na, C. Y.; Barker, E. S.; Stern, S. A.; Esposito, L. W.

    1993-01-01

    Magellan images have shown that the volcanic features are widespread over the surface of Venus. The question of whether there is active volcanism is important for understanding both the atmospheric and the geological processes on Venus. The thick cloud cover of Venus precludes any direct observation of active volcanoes even if they exist. The only means of monitoring the active volcanism on Venus at present seems to be remote sensing from Earth. Continuous monitoring of SO2 is important to establish the long term trend of SO2 abundance and to understand the physical mechanism responsible for the change.

  9. Infrared sensor modeling for discrimination of ground-based human activity

    NASA Astrophysics Data System (ADS)

    Flug, Eric; Deaver, Dawne

    2008-04-01

    In an initial effort to better understand how motion in human activities influences sensor performance, Night Vision and Electronic Sensors Directorate (NVESD) developed a perception experiment that tests an observer's ability to identify an activity in static and dynamic scenes. Current sensor models such as NVTherm were calibrated using static imagery of military vehicles but, given the current battlefield environment, the focus has shifted more towards discriminating human activities. In these activities, motion plays an important role but this role is not well quantified by the model. This study looks at twelve hostile and non-hostile activities that may be performed on an urban roadside such as digging a hole, raking, surveillance with binoculars, and holding several weapons. The forced choice experiment presents the activities in both static and dynamic scenes so that the effect of adding motion can be evaluated. The results are analyzed and attempts are made at relating observer performance to various static and dynamic metrics and ultimately developing a calibration for the sensor model.

  10. The VO and Ground-Based Data

    NASA Astrophysics Data System (ADS)

    Huchra, John

    The era of extremely large public databases in astronomy is upon us. such databases are opening the field to new research and new researchers. However it is important to be sure the resources are available to properly archive ground-based astronomical data and include the necessary quality checks and calibrations. A Virtual Observatory without proper archives will have limited usefulness. This also implies that with limited resources not all data can or should be archived. NASA already has a very good handle on US space-based astronomical data. Agencies and organizations that operate astronomical facilities particularly ground based observatories need to plan and budget for these activities now. We should not underestimate the effort required to produce high quality data products that will be useful for the broader community. Currently the best way to ""fill"" archives is with data ftom surveys. That will continue to be the case for most ground based observatories.

  11. Finding year-long activity cycles in ground-based and space-borne photometry

    NASA Astrophysics Data System (ADS)

    Vida, Krisztián; Oláh, Katalin; Szabó, Róbert

    2015-08-01

    Using long­term ground­based photometry of fast­rotating M­-dwarfs (EY Dra, V405 And, GSC 3377­0296 and V374 Peg), all with rotational periods near 0.5 day, but with different internal structures, we found activity cycles in the form of long-­term brightness changes, on the time scales of about one year. Using the cycling stars as templates, we searched for similar, fast rotating (P < 1d), active, late­-type targets in the Kepler Input Catalogue. Analysing the light curves of these 39 stars, we found hints of 300­-900 day­-long cycles in 9 cases detecting small variations in the rotation periods caused by differential rotation and the changing spot emergence latitudes over the cycle (i.e., the butterfly diagram).

  12. Tragaldabas: a muon ground-based detector for the study of the solar activity; first observations

    NASA Astrophysics Data System (ADS)

    José Blanco, Juan

    2016-04-01

    A new RPC-based cosmic ray detector, TRAGALDABAS (acronym of "TRAsGo for the AnaLysis of the nuclear matter Decay, the Atmosphere, the earth's B-field And the Solar activity") has been installed at the Univ. of Santiago de Compostela, Spain (N:42°52'34",W:8°33'37"). The detector, in its present layout, consists of three 1.8 m2 planes of three 1mm-gap glass RPCs. Each plane is readout with 120 pads with grounded guard electrodes between them to minimize the crosstalk noise. The main performances of the detectors are: an arrival time resolution of about ~300 ps, a tracking angular resolution below 3°, a detection efficiency close to 1, and a solid angle acceptance of ~5 srad. TRAGALDABAS will be able to monitor the cosmic ray low energy component strongly modulated by solar activity by mean the observation of secondary muons from the interaction between cosmic rays and atmospheric molecules. Its cadence and its angular resolution will allow to study in detail, small variations in cosmic ray anisotropy. These variations can be a key parameter to understand the effect of solar disturbances on the propagation of cosmic ray in the inner heliosphere and, maybe, provide a new tool for space weather analysis. In this work first TRAGALDABAS observations of solar events are shown

  13. Space-born and ground-based observations of a solar active region and a flare

    NASA Astrophysics Data System (ADS)

    Chiuderi Drago, F.

    Observational data of the active solar region AR 2490 are discussed with an eye to underlying physical processes. Ground- and spaceborne measurements were made by radio, optical, and XUV instrumentation. A double structure observed at 6 and 20 cm wavelengths was overlying a sunspot group which displayed north polarity. The 6 cm emission was attributed to free-free emission, while the 20 cm feature was thought to be caused by gyroresonance absorption. An analytical formulation was developed which described the thermal component for maximum X ray intensities. A flare observed on June 10, 1980 was detected on H-alpha and C IV spectrographic bands. The origin of the emissions was fixed at the two feet of the X ray loop, with a radio emission coming from the top of the loop.

  14. Movable Ground Based Recovery System for Reuseable Space Flight Hardware

    NASA Technical Reports Server (NTRS)

    Sarver, George L. (Inventor)

    2013-01-01

    A reusable space flight launch system is configured to eliminate complex descent and landing systems from the space flight hardware and move them to maneuverable ground based systems. Precision landing of the reusable space flight hardware is enabled using a simple, light weight aerodynamic device on board the flight hardware such as a parachute, and one or more translating ground based vehicles such as a hovercraft that include active speed, orientation and directional control. The ground based vehicle maneuvers itself into position beneath the descending flight hardware, matching its speed and direction and captures the flight hardware. The ground based vehicle will contain propulsion, command and GN&C functionality as well as space flight hardware landing cushioning and retaining hardware. The ground based vehicle propulsion system enables longitudinal and transverse maneuverability independent of its physical heading.

  15. Change detection and characterization of volcanic activity using ground based low-light and near infrared cameras to monitor incandescence and thermal signatures

    NASA Astrophysics Data System (ADS)

    Harrild, Martin; Webley, Peter; Dehn, Jonathan

    2015-04-01

    Knowledge and understanding of precursory events and thermal signatures are vital for monitoring volcanogenic processes, as activity can often range from low level lava effusion to large explosive eruptions, easily capable of ejecting ash up to aircraft cruise altitudes. Using ground based remote sensing techniques to monitor and detect this activity is essential, but often the required equipment and maintenance is expensive. Our investigation explores the use of low-light cameras to image volcanic activity in the visible to near infrared (NIR) portion of the electromagnetic spectrum. These cameras are ideal for monitoring as they are cheap, consume little power, are easily replaced and can provide near real-time data. We focus here on the early detection of volcanic activity, using automated scripts, that capture streaming online webcam imagery and evaluate image pixel brightness values to determine relative changes and flag increases in activity. The script is written in Python, an open source programming language, to reduce the overall cost to potential consumers and increase the application of these tools across the volcanological community. In addition, by performing laboratory tests to determine the spectral response of these cameras, a direct comparison of collocated low-light and thermal infrared cameras has allowed approximate eruption temperatures and effusion rates to be determined from pixel brightness. The results of a field campaign in June, 2013 to Stromboli volcano, Italy, are also presented here. Future field campaigns to Latin America will include collaborations with INSIVUMEH in Guatemala, to apply our techniques to Fuego and Santiaguito volcanoes.

  16. Change detection and characterization of volcanic activity using ground based low-light and near infrared cameras to monitor incandescence and thermal signatures

    NASA Astrophysics Data System (ADS)

    Harrild, M.; Webley, P.; Dehn, J.

    2014-12-01

    Knowledge and understanding of precursory events and thermal signatures are vital for monitoring volcanogenic processes, as activity can often range from low level lava effusion to large explosive eruptions, easily capable of ejecting ash up to aircraft cruise altitudes. Using ground based remote sensing techniques to monitor and detect this activity is essential, but often the required equipment and maintenance is expensive. Our investigation explores the use of low-light cameras to image volcanic activity in the visible to near infrared (NIR) portion of the electromagnetic spectrum. These cameras are ideal for monitoring as they are cheap, consume little power, are easily replaced and can provide near real-time data. We focus here on the early detection of volcanic activity, using automated scripts, that capture streaming online webcam imagery and evaluate image pixel brightness values to determine relative changes and flag increases in activity. The script is written in Python, an open source programming language, to reduce the overall cost to potential consumers and increase the application of these tools across the volcanological community. In addition, by performing laboratory tests to determine the spectral response of these cameras, a direct comparison of collocated low-light and thermal infrared cameras has allowed approximate eruption temperatures and effusion rates to be determined from pixel brightness. The results of a field campaign in June, 2013 to Stromboli volcano, Italy, are also presented here. Future field campaigns to Latin America will include collaborations with INSIVUMEH in Guatemala, to apply our techniques to Fuego and Santiaguito volcanoes.

  17. Evaluation of aerial photography for predicting trends in structural attributes of Australian woodland including comparison with ground-based monitoring data.

    PubMed

    Fensham, Roderick J; Bray, Steven G; Fairfax, Russell J

    2007-06-01

    The accurate assessment of trends in the woody structure of savannas has important implications for greenhouse accounting and land-use industries such as pastoralism. Two recent assessments of live woody biomass change from north-east Australian eucalypt woodland between the 1980s and 1990s present divergent results. The first estimate is derived from a network of permanent monitoring plots and the second from woody cover assessments from aerial photography. The differences between the studies are reviewed and include sample density, spatial scale and design. Further analyses targeting potential biases in the indirect aerial photography technique are conducted including a comparison of basal area estimates derived from 28 permanent monitoring sites with basal area estimates derived by the aerial photography technique. It is concluded that the effect of photo-scale; or the failure to include appropriate back-transformation of biomass estimates in the aerial photography study are not likely to have contributed significantly to the discrepancy. However, temporal changes in the structure of woodlands, for example, woodlands maturing from many smaller trees to fewer larger trees or seasonal changes, which affect the relationship between cover and basal area could impact on the detection of trends using the aerial photography technique. It is also possible that issues concerning photo-quality may bias assessments through time, and that the limited sample of the permanent monitoring network may inadequately represent change at regional scales. PMID:16828220

  18. Ground based automated telescope

    SciTech Connect

    Colgate, S.A.; Thompson, W.

    1980-01-01

    Recommendation that a ground-based automated telescope of the 2-meter class be built for remote multiuser use as a natural facility. Experience dictates that a primary consideration is a time shared multitasking operating system with virtual memory overlayed with a real time priority interrupt. The primary user facility is a remote terminal networked to the single computer. Many users must have simultaneous time shared access to the computer for program development. The telescope should be rapid slewing, and hence a light weight construction. Automation allows for the closed loop pointing error correction independent of extreme accuracy of the mount.

  19. Ground based infrared astronomy

    NASA Technical Reports Server (NTRS)

    Jennings, D. E.

    1988-01-01

    Infrared spectroscopic instrumentation has been developed for ground-based measurements of astrophysical objects in the intermediate infrared. A conventional Michelson interferometer is limited for astronomical applications in the intermediate infrared by quantum noise fluctuations in the radiation form the source and/or background incident on the detector, and the multiplex advantage is no longer available. One feasible approach to recovering the multiplex advantage is post-dispersion. The infrared signal after passing through telescope and interferometer, is dispersed by a low resolution grating spectrometer onto an array of detectors. The feasibility of the post-dispersion system has been demonstrated with observations of astrophysical objects in the 5 and 10 micrometer atmospheric windows from ground-based telescopes. During FY87/88 the post-disperser was used at the Kitt Peak 4-meter telescope and McMath telescope with facility Fourier transform spectrometers. Jupiter, Saturn, Mars, and Venus were observed. On Jupiter, the resolution at 12 micrometer was 0.01/cm, considerably higher than had been acheived previously. The spectrum contains Jovian ethane and acetylene emission. Construction was begun on the large cryogenic grating spectrometer.

  20. Connecting Io's volcanic activity to the Io plasma torus: comparison of Galileo/NIMS volcanic and ground-based torus observations

    NASA Astrophysics Data System (ADS)

    Magalhaes, F. P.; Lopes, R. M. C.; Rathbun, J. A.; Gonzalez, W. D.; Morgenthaler, J. P.; Echer, E.; Echer, M. P. D. S.

    2015-12-01

    Io, the innermost of the Jupiter's four Galilean moons, is a remarkable object in the Solar System, due to its intense and energetic volcanic activity. The volcanic sulfur and oxygen in Io's tenuous atmosphere escapes forming an extended neutral cloud around Io and Jupiter. Subsequently, by ionization and pickup ions, a ring of charged particles encircling Jupiter is created, forming the Io plasma torus. Considering this scenario, it is reasonable to expect that the Io plasma torus should be affected by changes in Io's volcanism. Interactions between Io and the Jovian environment is unique and yet not very well understood. Here we present two sets of observations. One from the Galileo Near-Infrared Imaging Spectrograph (NIMS) instrument, which obtained spectral image cubes between 0.7 and 5.2 microns. The other dataset is from ground-based observations of the [SII] 6731 Å emission lines from the Io plasma torus, obtained at McMath-Pierce Solar Telescope, at Kitt Peak. Our dataset from the [SII] 6731 Å emission lines cover more years than the one from the NIMS data. The years presented in this work for a comparative study are from 1998 through 2001. Using the NIMS instrument we were able to identify which volcanoes were active and measure their level of activity. From the [SII] 6731 Å emission lines we were able to trace the densest part of the torus and also the brightness of both ansa. By comparing the results from the Galileo instrument and the ground-based observations, we are exploring how the Io plasma torus responds to large eruptions from Io. We aim with this study to help improve our understanding of this complex coupled system, Jupiter-Io.

  1. Yield and quality prediction using satellite passive imagery and ground-based active optical sensors in sugar beet, spring wheat, corn, and sunflower

    NASA Astrophysics Data System (ADS)

    Bu, Honggang

    Remote sensing is one possible approach for improving crop nitrogen use efficiency to save fertilizer cost, reduce environmental pollution, and improve crop yield and quality. Feasibility and potential of using remote sensing tools to predict crops yield and quality as well as detect nitrogen requirements, application timing, rate, and places in season were investigated based on 2012-2013 two-year and four-crop (corn, spring wheat, sugar beet, and sunflower) study. Two ground-based active optical sensors, GreenSeeker and Holland Scientific Crop Circle, and the RapidEye satellite imagery were used to collect sensing data. Highly significant statistical relationships between INSEY (NDVI normalized by growing degree days) and crop yield and quality indices were found for all crops, indicating that remote sensing tools may be useful for managing in-season crop yield and quality prediction.

  2. Application oft triple collocation in ground-based validation of soil moisture active/passive (SMAP) level 2 data products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The validation of the soil moisture retrievals from the recently-launched NASA Soil Moisture Active/Passive (SMAP) satellite is important prior to their full public release. Uncertainty in attempts to characterize footprint-scale surface-layer soil moisture using point-scale ground observations has ...

  3. Following solar activity with geomagnetic and cosmic-ray ground-based stations in the Iberian Peninsula region

    NASA Astrophysics Data System (ADS)

    Villasante-Marcos, Victor; José Blanco, Juan; Miquel Torta, Joan; Catalán, Manuel; Ribeiro, Paulo; Morozova, Anna; Tordesillas, José Manuel; Solé, Germán; Gomis-Moreno, Almudena

    2016-04-01

    The Iberian Peninsula is located in the South-West of Europe between 36°00' N and 43°47' N and between 9°29' W and 3°19' E. There are four Geomagnetic Observatories currently operative in this area devoted to the observation of the Earth's magnetic field: Observatori de l'Ebre (NE Spain); Observatorio de San Pablo de los Montes (central Spain); Observatorio de San Fernando (southern Spain); Observatório de Coimbra (central Portugal); plus another one, Observatorio de Güímar, in Tenerife (Canary Islands, Spain). There is also one neutron monitor located in Guadalajara (central Spain; 40°38' N, 3°9' W at 708 m asl) continuously measuring the arrival of cosmic rays to the Earth's surface. In this work we show combined observations of these six stations during events caused by solar activity. We analyze them looking for differences that could imply extremely local effects caused by the response of the Earth's magnetosphere and ionosphere to solar activity.

  4. Optical design of an all-reflecting, high resolution camera for active-optics on ground-based telescopes

    NASA Astrophysics Data System (ADS)

    Richardson, E. H.; Morbey, C. L.

    Optical designs of high-resolution all-mirror cameras for the active optics of the 3.6-m Canada-France-Hawaii Telescope (CFHT) with classical optics (a paraboloidal primary), and the 2.2-m University of Hawaii telescope with Ritchey-Chretien (R-C) optics (a hyperboloidal primary), are presented. An oblate spheroid is used to produce longer focal ratios in the R-C telescope, lessening its disadvantage of a very small field of good definition at focal ratios longer than the optimized secondary focal ratio. Unlike the R-C telescope, the CFHT is not coma-free, and the prolate spheroid works well as its tertiary mirror. In the present camera design, the scale at the final focus is such that 0.25 arcsec covers 0.065 mm in order to match the resolution of the available detector. These cameras are off-axis, resulting in a slight change of magnification with the field rotation of alt-azimuth telescopes.

  5. Use of active and passive ground based remote sensors to explore cloud droplet modifications in aerosol-cloud interactions

    NASA Astrophysics Data System (ADS)

    Han, Zaw Thet

    We explore the potential aerosol impact on cloud optical properties which is a strong modifier of climate forcing. Previous studies have shown that increased aerosol loading can affect the cloud optical properties such as cloud optical depth and cloud droplet effective radius in rural areas, particularly at the Atmospheric Radiation Measurement, Southern Great Plain site. In this study, we attempt to observe and quantify aerosol-cloud interaction over New York City, using a combination of passive and active radiometric sensors. In particular, we look for signatures of the Twomey indirect effect which states that the droplet size of water phase clouds will decrease with increasing aerosols. We find that under certain conditions, a strong signature is found between the cloud drop effective radius and extinction and this effect is in part due to vertical wind uptake. In demonstrating the Aerosol Cloud Interaction, we use multiple approaches. For example, we derive the integrated liquid water path using both a multiband neural network and dual channel approach and show general agreement between two methods while the DC approach seems more robust. We also find that these measurements are difficult and sensitive to the position of the aerosols relative to the cloud base. As a corollary, we explore whether near surface aerosol loading can effecting the cloud by using particulate matter (PM2.5) and find that the effects are too variable to be given any statistical weight. Finally, we explore the potential of modifying our approach to remove the noisy and difficult measurement of Raman LIDAR derived extinction with calibrated LIDAR backscatter. The results seem to show a general improvement in correlation and offer the possibility of increasing the number of cases observed.

  6. Sequential digital elevation models of active lava flows from ground-based stereo time-lapse imagery

    NASA Astrophysics Data System (ADS)

    James, M. R.; Robson, S.

    2014-11-01

    We describe a framework for deriving sequences of digital elevation models (DEMs) for the analysis of active lava flows using oblique stereo-pair time-lapse imagery. A photo-based technique was favoured over laser-based alternatives due to low equipment cost, high portability and capability for network expansion, with images of advancing flows captured by digital SLR cameras over durations of up to several hours. However, under typical field scale scenarios, relative camera orientations cannot be rigidly maintained (e.g. through the use of a stereo bar), preventing the use of standard stereo time-lapse processing software. Thus, we trial semi-automated DEM-sequence workflows capable of handling the small camera motions, variable image quality and restricted photogrammetric control that result from the practicalities of data collection at remote and hazardous sites. The image processing workflows implemented either link separate close-range photogrammetry and traditional stereo-matching software, or are integrated in a single software package based on structure-from-motion (SfM). We apply these techniques in contrasting case studies from Kilauea volcano, Hawaii and Mount Etna, Sicily, which differ in scale, duration and image texture. On Kilauea, the advance direction of thin fluid lava lobes was difficult to forecast, preventing good distribution of control. Consequently, volume changes calculated through the different workflows differed by ∼10% for DEMs (over ∼30 m2) that were captured once a minute for 37 min. On Mt. Etna, more predictable advance (∼3 m h-1 for ∼3 h) of a thicker, more viscous lava allowed robust control to be deployed and volumetric change results were generally within 5% (over ∼500 m2). Overall, the integrated SfM software was more straightforward to use and, under favourable conditions, produced results comparable to those from the close-range photogrammetry pipeline. However, under conditions with limited options for photogrammetric

  7. Active-Layer Soil Moisture Content Regional Variations in Alaska and Russia by Ground-Based and Satellite-Based Methods, 2002 Through 2014

    NASA Astrophysics Data System (ADS)

    Muskett, Reginald; Romanovsky, Vladimir; Cable, William; Kholodov, Alexander

    2016-04-01

    Soil moisture is a vital physical parameter of the active-layer in permafrost environments, and associated biological and geophysical processes operative at the microscopic to hemispheric spatial scales and at hourly to multidecadal time scales. While in-situ measurements can give the highest quality of information on a site-specific basis, the vast permafrost terrains of North America and Eurasia require space-based techniques for assessments of cause and effect and long-term changes and impacts from the changes of permafrost and the active-layer. Satellite-based 6.925 and 10.65 GHz sensor algorithmic retrievals of soil moisture by Advanced Microwave Scanning Radiometer - Earth Observation System (AMSR-E) onboard NASA-Aqua and follow-on AMSR2 onboard JAXA-Global Change Observation Mission - Water-1 are ongoing since July 2002. Accurate land-surface temperature and vegetation parameters are critical to the success of passive microwave algorithmic retrieval schemes. Strategically located soil moisture measurements are needed for spatial and temporal co-location evaluation and validation of the space-based algorithmic estimates. We compare on a daily basis ground-based (subsurface-probe) 50- and 70-MHz radio-frequency soil moisture measurements with NASA- and JAXA-algorithmic retrieval passive microwave retrievals. We find improvements in performance of the JAXA-algorithm (AMSR-E reprocessed and AMSR2 ongoing) relative to the earlier NASA-algorithm version. In the boreal forest regions accurate land-surface temperatures and vegetation parameters are still needed for algorithmic retrieval success. Over the period of AMSR-E retrievals we find evidence of at the high northern latitudes of growing terrestrial radio-frequency interference in the 10.65 GHz channel soil moisture content. This is an important error source for satellite-based active and passive microwave remote sensing soil moisture retrievals in Arctic regions that must be addressed. Ref: Muskett, R

  8. SOLAR-LIKE OSCILLATIONS AND ACTIVITY IN PROCYON: A COMPARISON OF THE 2007 MOST AND GROUND-BASED RADIAL VELOCITY CAMPAIGNS

    SciTech Connect

    Huber, Daniel; Bedding, Timothy R.; Stello, Dennis; Arentoft, Torben; Kjeldsen, Hans; Gruberbauer, Michael; Guenther, David B.; Houdek, Guenter; Kallinger, Thomas; Weiss, Werner W.; Matthews, Jaymie M.

    2011-04-20

    We compare the simultaneous 2007 space-based MOST photometry and ground-based radial velocity (RV) observations of the F5 star Procyon. We identify slow variations in the MOST data that are similar to those reported in the RV time series and confirm by comparison with the Sun that these variations are likely the signature of stellar activity. The MOST power spectrum yields clear evidence for individual oscillation frequencies that match those found in the RV data by Bedding et al. We identify the same ridges due to modes of different spherical degree in both data sets, but are not able to confirm a definite ridge identification using the MOST data. We measure the luminosity amplitude per radial mode A{sub l=0,phot} = 9.1 {+-} 0.5 ppm. Combined with the estimate for the RV data by Arentoft et al., this gives a mean amplitude ratio of A{sub l=0,phot}/A{sub l=0,RV} = 0.24 {+-} 0.02 ppm cm{sup -1} s, considerably higher than expected from scaling relations but in reasonable agreement with theoretical models by Houdek. We also compare the amplitude ratio as a function of frequency and find that the maximum of the oscillation envelope is shifted to higher frequencies in photometry than in velocity.

  9. Distant activity of 67P/Churyumov-Gerasimenko in 2014: Ground-based results during the Rosetta pre-landing phase

    NASA Astrophysics Data System (ADS)

    Snodgrass, Colin; Jehin, Emmanuel; Manfroid, Jean; Opitom, Cyrielle; Fitzsimmons, Alan; Tozzi, Gian Paolo; Faggi, Sara; Yang, Bin; Knight, Matthew M.; Conn, Blair C.; Lister, Tim; Hainaut, Olivier; Bramich, D. M.; Lowry, Stephen C.; Rozek, Agata; Tubiana, Cecilia; Guilbert-Lepoutre, Aurélie

    2016-04-01

    Context. As the ESA Rosetta mission approached, orbited, and sent a lander to comet 67P/Churyumov-Gerasimenko in 2014, a large campaign of ground-based observations also followed the comet. Aims: We constrain the total activity level of the comet by photometry and spectroscopy to place Rosetta results in context and to understand the large-scale structure of the comet's coma pre-perihelion. Methods: We performed observations using a number of telescopes, but concentrate on results from the 8 m VLT and Gemini South telescopes in Chile. We use R-band imaging to measure the dust coma contribution to the comet's brightness and UV-visible spectroscopy to search for gas emissions, primarily using VLT/FORS. In addition we imaged the comet in near-infrared wavelengths (JHK) in late 2014 with Gemini-S/Flamingos-2. Results: We find that the comet was already active in early 2014 at heliocentric distances beyond 4 au. The evolution of the total activity (measured by dust) followed previous predictions. No gas emissions were detected despite sensitive searches. Conclusions: The comet maintains a similar level of activity from orbit to orbit, and is in that sense predictable, meaning that Rosetta results correspond to typical behaviour for this comet. The gas production (for CN at least) is highly asymmetric with respect to perihelion, as our upper limits are below the measured production rates for similar distances post-perihelion in previous orbits. Based on observations made with ESO telescopes at the La Silla Paranal Observatory under programme IDs 592.C-0924, 093.C-0593, 094.C-0054, and at Gemini South under GS-2014B-Q-15 and GS-2014B-Q-76.

  10. Active-Layer Soil Moisture Content Regional Variations in Alaska and Russia by Ground-Based and Satellite-Based Methods, 2002 Through 2014

    NASA Astrophysics Data System (ADS)

    Muskett, Reginald; Romanovsky, Vladimir; Cable, William; Kholodov, Alexander

    2015-04-01

    Soil moisture is a vital physical parameter of the active-layer in permafrost environments, and associated biological and geophysical processes operative at the microscopic to hemispheric spatial scales and at hourly to multidecadal time scales. While in-situ measurements can give the highest quality of information on a site-specific basis, the vast permafrost terrains of North America and Eurasia require space-based techniques for assessments of cause and effect and long-term changes and impacts from the changes of permafrost and the active-layer. Satellite-based 6.925 and 10.65 GHz sensor algorithmic retrievals of soil moisture by Advanced Microwave Scanning Radiometer - Earth Observation System (AMSR-E) onboard NASA-Aqua and follow-on AMSR2 onboard JAXA-Global Change Observation Mission - Water-1 are ongoing since July 2002. Accurate land-surface temperature and vegetation parameters are critical to the success of passive microwave algorithmic retrieval schemes. Strategically located soil moisture measurements are needed for spatial and temporal co-location evaluation and validation of the space-based algorithmic estimates. We compare on a daily basis ground-based (subsurface-probe) 50- and 70-MHz radio-frequency soil moisture measurements with NASA- and JAXA-algorithmic retrieval passive microwave retrievals. We find improvements in performance of the JAXA-algorithm (AMSR-E reprocessed and AMSR2 ongoing) relative to the earlier NASA-algorithm version. In the boreal forest regions accurate land-surface temperatures and vegetation parameters are still needed for algorithmic retrieval success. Over the period of AMSR-E retrievals we find evidence of at the high northern latitudes of growing terrestrial radio-frequency interference in the 10.65 GHz channel soil moisture content. This is an important error source for satellite-based active and passive microwave remote sensing soil moisture retrievals in Arctic regions that must be addressed. Ref: International

  11. Solar-like Oscillations and Activity in Procyon: A Comparison of the 2007 MOST and Ground-based Radial Velocity Campaigns

    NASA Astrophysics Data System (ADS)

    Huber, Daniel; Bedding, Timothy R.; Arentoft, Torben; Gruberbauer, Michael; Guenther, David B.; Houdek, Günter; Kallinger, Thomas; Kjeldsen, Hans; Matthews, Jaymie M.; Stello, Dennis; Weiss, Werner W.

    2011-04-01

    We compare the simultaneous 2007 space-based MOST photometry and ground-based radial velocity (RV) observations of the F5 star Procyon. We identify slow variations in the MOST data that are similar to those reported in the RV time series and confirm by comparison with the Sun that these variations are likely the signature of stellar activity. The MOST power spectrum yields clear evidence for individual oscillation frequencies that match those found in the RV data by Bedding et al. We identify the same ridges due to modes of different spherical degree in both data sets, but are not able to confirm a definite ridge identification using the MOST data. We measure the luminosity amplitude per radial mode A l=0,phot = 9.1 ± 0.5 ppm. Combined with the estimate for the RV data by Arentoft et al., this gives a mean amplitude ratio of A l=0,phot/A l=0,RV = 0.24 ± 0.02 ppm cm-1 s, considerably higher than expected from scaling relations but in reasonable agreement with theoretical models by Houdek. We also compare the amplitude ratio as a function of frequency and find that the maximum of the oscillation envelope is shifted to higher frequencies in photometry than in velocity. Based on data from the MOST satellite, a Canadian Space Agency mission, jointly operated by Dynacon Inc., the University of Toronto Institute for Aerospace Studies and the University of British Columbia, with the assistance of the University of Vienna.

  12. Active-Layer Soil Moisture Content Regional Variations in Alaska and Russia by Ground-Based and Satellite-Based Methods, 2002 Through 2014

    NASA Astrophysics Data System (ADS)

    Muskett, R. R.; Romanovsky, V. E.; Cable, W.; Kholodov, A. L.

    2015-12-01

    Soil moisture is a vital physical parameter of the active-layer in permafrost environments, and associated biological and geophysical processes operative at the microscopic to hemispheric spatial scales and at hourly to multidecadal time scales. While in-situ measurements can give the highest quality of information on a site-specific basis, the vast permafrost terrains of North America and Eurasia require space-based techniques for assessments of cause and effect and long-term changes and impacts from the changes of permafrost and the active-layer. Satellite-based 6.925 and 10.65 GHz sensor algorithmic retrievals of soil moisture by Advanced Microwave Scanning Radiometer - Earth Observation System (AMSR-E) onboard NASA-Aqua and follow-on AMSR2 onboard JAXA-Global Change Observation Mission - Water-1 are ongoing since July 2002. Accurate land-surface temperature and vegetation parameters are critical to the success of passive microwave algorithmic retrieval schemes. Strategically located soil moisture measurements are needed for spatial and temporal co-location evaluation and validation of the space-based algorithmic estimates. We compare on a daily basis ground-based (subsurface-probe) 50- and 70-MHz radio-frequency soil moisture measurements with NASA- and JAXA-algorithmic retrieval passive microwave retrievals. We find improvements in performance of the JAXA-algorithm (AMSR-E reprocessed and AMSR2 ongoing) relative to the earlier NASA-algorithm version. In the boreal forest regions accurate land-surface temperatures and vegetation parameters are still needed for algorithmic retrieval success. Over the period of AMSR-E retrievals we find evidence of at the high northern latitudes of growing terrestrial radio-frequency interference in the 10.65 GHz channel soil moisture content. This is an important error source for satellite-based active and passive microwave remote sensing soil moisture retrievals in Arctic regions that must be addressed. Ref: Muskett, R

  13. Ground-Based Telescope Parametric Cost Model

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip; Rowell, Ginger Holmes

    2004-01-01

    A parametric cost model for ground-based telescopes is developed using multi-variable statistical analysis, The model includes both engineering and performance parameters. While diameter continues to be the dominant cost driver, other significant factors include primary mirror radius of curvature and diffraction limited wavelength. The model includes an explicit factor for primary mirror segmentation and/or duplication (i.e.. multi-telescope phased-array systems). Additionally, single variable models based on aperture diameter are derived. This analysis indicates that recent mirror technology advances have indeed reduced the historical telescope cost curve.

  14. Ground-based observations of 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Snodgrass, C.

    2015-10-01

    I will described the campaign of observations from ground-based (and Earth orbiting) telescopes that supports the Rosetta mission. Rosetta gets closer to the nucleus than any previous mission, and returns wonderfully detailed measurements from the heart of the comet, but at the cost of not seeing the large scale coma and tails. The ground-based campaign fills in the missing part of the picture, studying the comet at #1000km resolution, and following how the overall activity of the comet varies. These data provide context information for Rosetta, so changes in the inner coma seen by the spacecraft can be correlated with the phenomena observable in comets. This not only helps to complete our understanding of the activity of 67P, but also allows us to compare it with other comets that are only observed from the ground, and in that way extend the results of the Rosetta mission to the wider population. The ground-based campaign includes observations with nearly all major facilities world-wide. In 2014 the majority of data came from the ESO VLT, as the comet was still relatively faint and in Southern skies, but as it returns to visibility from Earth in 2015 it will be considerably brighter, approaching its perihelion in August, and at Northern declinations. I will show results from the 2014 campaign, including visible wavelength photometry and spectroscopy, and the latest results from early 2015 observations. I will also describe the varied observations that will be included in the campaign post-perihelion, and how all of these results fit around what we are learning about 67P from Rosetta.

  15. Ground-based IRCM testing

    NASA Astrophysics Data System (ADS)

    Greer, Derek; Owen, Mark

    2010-04-01

    Recent advances in the ability to perform comprehensive ground based Infrared Countermeasure (IRCM) testing have the capability to fill the Test and Evaluation (T&E) gaps for existing and future weapons system acquisition. IRCM testing has historically been dominated and in a manner limited by expensive live fire testing requirements. While live fire testing is a vital part of IRCM T&E, next generation technological developments now enable closed-loop, ground-based IRCM testing to provide valuable complementary test data at a much lower cost. The high cost and limited assets that have prevented live fire and flight testing from providing a thorough hardware based data set required for previous T&E analysis is no longer an issue. In the past, traditional physics based digital system model (DSM) analysis has been utilized to augment the IRCM data sets to make them statistically significant. While DSM is a useful tool in the development of IRCM systems, the newly developed installed system testing utilizing a hardware-in-the-loop construct provides for an enhanced level of fidelity and assurance that the systems will meet the warfighter's needs. The goal of the newly developed test technologies is to develop a statistical significant data set utilizing hardware-in-the-loop at a significantly lower cost than historical methods.

  16. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. 6: Variability of NGC 3783 from ground-based data

    NASA Technical Reports Server (NTRS)

    Stirpe, G. M.; Winge, C.; Altieri, B.; Alloin, D.; Aguero, E. L.; Anupama, G. C.; Ashley, R.; Bertram, R.; Calderon, J. H.; Catchpole, R. M.

    1994-01-01

    The Seyfert 1 galaxy NGC 3783 was intensely monitored in several bands between 1991 December and 1992 August. This paper presents the results from the ground-based observations in the optical and near-IR bands, which complement the data set formed by the International Ultraviolet Explorer (IUE) spectra, discussed elsewhere. Spectroscopic and photometric data from several observatories were combined in order to obtain well-sampled light curves of the continuum and of H(beta). During the campaign the source underwent significant variability. The light curves of the optical continuum and of H(beta) display strong similarities to those obtained with the IUE. The near-IR flux did not vary significantly except for a slight increase at the end of the campaign. The cross-correlation analysis shows that the variations of the optical continuum have a lag of 1 day or less with respect to those of the UV continuum, with an uncertainty of is less than or equal to 4 days. The integrated flux of H(beta) varies with a delay of about 8 days. These results confirm that (1) the continuum variations occur simultaneously or with a very small lag across the entire UV-optical range, as in the Seyfert galaxy NGC 5548; and (2) the emission lines of NGC 3783 respond to ionizing continuum variations with less delay than those of NGC 5548. As observed in NGC 5548, the lag of H(beta) with respect to the continuum is greater than those of the high-ionization lines.

  17. Examining auroral downward current region processes using ground based data

    NASA Astrophysics Data System (ADS)

    Michell, Robert Gregory

    observed 7 distinct periods of NEIAL activity. These times correspond to (a) when the polar cap boundary of the auroral arcs passed through the magnetic zenith and (b) when small-scale filamentary dark structure was present in the magnetic zenith. These observations are consistent with NEIALs occurring within the same auroral morphology which is known to contain broad-band extremely low frequency (BBELF) wave activity. By comparing the densities at which NEIALs have been observed by previous studies, it is found that NEIALs occur at densities roughly between 5 and 30 x1010 m-3. The observations presented in this dissertation support the hypothesis that NEIALs and BBELF are differently observed aspects of the same auroral phenomenon. It is a goal of this thesis to connect these ground-based observations with previous in situ measurements and identify DCRs from the ground. A relation between NEIALs and the in situ signature of BBELF wave activity, provides a link between the in situ measurements and the ground-based observations. There are no actual ground-based/in situ conjugate events in this study. The focus here is to compare the optical observations to the morphology and auroral context of DCRs as measured in situ by previous studies. The use of ground-based observational techniques for observing DCR processes has many implications. These include identifying and following the temporal and spatial evolution of DCRs as well as being able to identify regions of potential ion outflow on a large spatial and temporal scale using ground based optical observations.

  18. Frequency based detection and monitoring of small scale explosive activity by comparing satellite and ground based infrared observations at Stromboli Volcano, Italy

    NASA Astrophysics Data System (ADS)

    Worden, Anna; Dehn, Jonathan; Ripepe, Maurizio; Donne, Dario Delle

    2014-08-01

    Thermal activity is a common precursor to explosive volcanic activity. The ability to use these thermal precursors to monitor the volcano and obtain early warning about upcoming activity is beneficial for both human safety and infrastructure security. By using a very reliably active volcano, Stromboli Volcano in Italy, a method has been developed and tested to look at changes in the frequency of small scale explosive activity and how this activity changes prior to larger, ash producing explosive events. Thermal camera footage was used to designate parameters for typical explosions at Stromboli (size of spatter field, cooling rate, frequency of explosions) and this information was applied to characterize explosions in satellite imagery. Satellite data from The National Aeronautics and Space Administration's Moderate Resolution Imaging Spectroradiometer (MODIS) and US/Japan designed Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) for numerous periods in 2002 to 2009 were analyzed for thermal features which were used to calculate an estimate of the level of activity during the given time period. The results at Stromboli showed a high level of small scale explosions which stop completely prior to large paroxysmal eruptive episodes. This activity also corresponds well to seismic and infrasonic records at Stromboli, indicating that this thermal infrared monitoring method may be used in conjunction with other detection methods where available, and also indicates that it may be a useful method for volcano monitoring when other methods (e.g. seismic instrumentation, infrasound arrays, etc.) are not available.

  19. Cokriging with ground-based radiometry

    NASA Technical Reports Server (NTRS)

    Atkinson, P. M.; Webster, R.; Curran, P. J.

    1992-01-01

    The formulas for cokriging and a coherent coregionalization model are presented. The model is applied to design sampling strategies for surveys using a ground-based radiometer. Results indicate that cokriging based on measured radiation is nine times as efficient as kriging the cover alone. It is concluded that cokriging in conjunction with ground-based radiometry provides an economical and operational technique for using reflectance to estimate the earth surface properties.

  20. Ground-Based Sensing System for Weed Mapping in Cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A ground-based weed mapping system was developed to measure weed intensity and distribution in a cotton field. The weed mapping system includes WeedSeeker® PhD600 sensor modules to indicate the presence of weeds between rows, a GPS receiver to provide spatial information, and a data acquisition and ...

  1. Ground-Based Lidar Measurements During the CALIPSO and Twilight Zone (CATZ) Campaign

    NASA Technical Reports Server (NTRS)

    Berkoff, Timothy; Qian, Li; Kleidman, Richard; Stewart, Sebastian; Welton, Ellsworth; Li, Zhu; Holbem, Brent

    2008-01-01

    The CALIPSO and Twilight Zone (CATZ) field campaign was carried out between June 26th and August 29th of 2007 in the multi-state Maryland-Virginia-Pennsylvania region of the U.S. to study aerosol properties and cloud-aerosol interactions during overpasses of the CALIPSO satellite. Field work was conducted on selected days when CALIPSO ground tracks occurred in the region. Ground-based measurements included data from multiple Cimel sunphotometers that were placed at intervals along a segment of the CALIPSO ground-track. These measurements provided sky radiance and AOD measurements to enable joints inversions and comparisons with CALIPSO retrievals. As part of this activity, four ground-based lidars provided backscatter measurements (at 523 nm) in the region. Lidars at University of Maryland Baltimore County (Catonsville, MD) and Goddard Space Flight Center (Greenbelt, MD) provided continuous data during the campaign, while two micro-pulse lidar (MPL) systems were temporarily stationed at various field locations directly on CALIPSO ground-tracks. As a result, thirteen on-track ground-based lidar observations were obtained from eight different locations in the region. In some cases, nighttime CALIPSO coincident measurements were also obtained. In most studies reported to date, ground-based lidar validation efforts for CALIPSO rely on systems that are at fixed locations some distance away from the satellite ground-track. The CATZ ground-based lidar data provide an opportunity to examine vertical structure properties of aerosols and clouds both on and off-track simultaneously during a CALIPSO overpass. A table of available ground-based lidar measurements during this campaign will be presented, along with example backscatter imagery for a number of coincident cases with CALIPSO. Results indicate that even for a ground-based measurements directly on-track, comparisons can still pose a challenge due to the differing spatio-temporal properties of the ground and satellite

  2. Ground based research in microgravity materials processing

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.; Rathz, Tom

    1994-01-01

    The core activities performed during this time period have been concerned with tracking the TEMPEST experiments on the shuttle with drops of Zr, Ni, and Nb alloys. In particular a lot of Zr drops are being made to better define the recalescence characteristics of that system so that accurate comparisons of the drop tube results with Tempest can be made. A new liner, with minimal reflectivity characteristics, has been inserted into the drop tube in order to improve the recalescence measurements of the falling drops. The first installation to make the geometric measurements to ensure a proper fit has been made. The stovepipe sections are currently in the shop at MSFC being painted with low reflectivity black paint. Work has also continued on setting up the MEL apparatus obtained from Oak Ridge in the down stairs laboratory at the Drop Tube Facilities. Some ground-based experiments on the same metals as are being processed on TEMPEST are planned for the MEL. The flight schedules for the KC-135 experiments are still to be determined in the near future.

  3. Challenges and Rewards in Ground-Based Observing

    NASA Astrophysics Data System (ADS)

    Reardon, Kevin P.

    2016-05-01

    DKIST will be largest ground-based project in solar physics, and will offer access and data to the whole community. In pursuit of exciting science, many users may have their first encounters with high-resolution, ground-based solar observations. New facilities, space or ground-based, all bring particular signatures in their data. While tools or processed datasets might serve to minimize such non-solar signatures, it is nonetheless important for users to understand the impacts on observation planning, the nature of the corrections applied, and any residual effects on their data.In this talk I will review some of the instrumental and atmospheric signatures that are important for ground-based observing, in particular in planning for the potential capabilities of the DKIST Data Center. These techniques include image warping, local PSF deconvolution, atmospheric dispersion correction, and scattered light removal. I will present examples of data sets afflicted by such problems as well as some of the algorithms used in characterizing and removing these contributions. This will demonstrate how even with the challenges of observing through a turbulent atmosphere, it is possible to achieve dramatic scientific results.

  4. Synergy benefit in temperature, humiditiy and cloud property profiling by integrating ground based and satellite measurements

    NASA Astrophysics Data System (ADS)

    Ebell, K.; Orlandi, E.; Hünerbein, A.; Crewell, S.; Löhnert, U.

    2012-12-01

    Accurate, highly vertically resolved temperature, humidity and cloud property profiles are needed for many applications. They are essential for climate monitoring, a better process understanding and the subsequent improvement of parameterizations in numerical weather prediction and climate models. In order to provide such profiles with a high temporal resolution, multiple wavelength active and passive remote sensing techniques available at ground based observatories, e.g. the Atmospheric Radiation Measruement (ARM) Program and Cloudnet facilities, need to be exploited. In particular, the Integrated Profiling Technique (IPT, Löhnert et al., 2008) has been successfully applied to simultaneously derive profiles of temperature, humidity and liquid water by a Bayesian based retrieval using a combination of ground based microwave radiometer, cloud radar and a priori information. Within the project ICOS (Integrating Cloud Observations from Ground and Space - a Way to Combine Time and Space Information), we develop a flexible IPT, which allows for the combination of a variety of ground based measurements from cloud radar, microwave radiometer (MWR) and IR spectrometer as well as satellite based information from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) onboard of METEOSAT. As ground based observations are mainly sensitive to the lower parts of the troposphere, the satellite measurements provide complementary information and are thus expected to improve the estimates of the thermodynamic and cloud property profiles, i. e. hydrometeor content and effective radius, considerably. In addition to the SEVIRI IR measurements, which are provided with a high repetition time, information from polar orbiting satellites could be included. In paticular, the potential of the Advanced Microwave Sounding Unit-A (AMSU-A) and Microwave Sounding Unit (MHS) in the retrieval is investigated. In order to understand the improvement by integrating the measurements of the above

  5. Everglades National Park Including Biscayne National Park. Activity Book.

    ERIC Educational Resources Information Center

    Ruehrwein, Dick

    Intended to help elementary school children learn about the resources of the Everglades and Biscayne National Parks, this activity book includes information, puzzles, games, and quizzes. The booklet deals with concepts related to: (1) the seasons; (2) fire ecology; (3) water; (4) fish; (5) mammals; (6) mosquitos; (7) birds; (8) venomous snakes;…

  6. High resolution images of Venus from ground-based radar

    NASA Technical Reports Server (NTRS)

    Jurgens, R. F.; Slade, M. A.; Robinett, L.; Brokl, S.; Downs, G. S.

    1988-01-01

    The Goldstone Deep Space Station ground-based synthetic aperture radar system has been used to obtain radar images of Venus with resolutions of close to 1.3 km. Observations were made at 12.5 cm wavelength using circular polarization. From 12 days of observations during the 1986 inferior conjunction, three images have been selected for initial processing. The images show remarkable surface features including craters, ridges, and regions of high Fresnel reflectivity in the plains region.

  7. MSFC Skylab ground-based astronomy program

    NASA Technical Reports Server (NTRS)

    Duncan, B. J.

    1974-01-01

    The Skylab Ground-Based Astronomy Program (SGAP) was conducted to enhance the data base of solar physics obtained during the Apollo Telescope Mount (ATM) mission flown in conjunction with the Skylab orbital station. Leading solar physicists from various observatories obtained data from the ground at the same time that orbital data were being acquired by ATM. The acquisition of corollary solar data from the ground simultaneously with the ATM orbital observations helped to provide a broader basis for understanding solar physics by increasing spectral coverage and by the use of additional sophisticated instruments of various types. This report briefly describes the individual tasks and the associated instrumentation selected for this ground-based program and contains as appendices, the final reports from the Principal Investigators.

  8. Ground-based Nuclear Detonation Detection (GNDD) Technology Roadmap

    SciTech Connect

    Casey, Leslie A.

    2014-01-13

    This GNDD Technology Roadmap is intended to provide guidance to potential researchers and help management define research priorities to achieve technology advancements for ground-based nuclear explosion monitoring science being pursued by the Ground-based Nuclear Detonation Detection (GNDD) Team within the Office of Nuclear Detonation Detection in the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy (DOE). Four science-based elements were selected to encompass the entire scope of nuclear monitoring research and development (R&D) necessary to facilitate breakthrough scientific results, as well as deliver impactful products. Promising future R&D is delineated including dual use associated with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Important research themes as well as associated metrics are identified along with a progression of accomplishments, represented by a selected bibliography, that are precursors to major improvements to nuclear explosion monitoring.

  9. Silicon carbide optics for space and ground based astronomical telescopes

    NASA Astrophysics Data System (ADS)

    Robichaud, Joseph; Sampath, Deepak; Wainer, Chris; Schwartz, Jay; Peton, Craig; Mix, Steve; Heller, Court

    2012-09-01

    Silicon Carbide (SiC) optical materials are being applied widely for both space based and ground based optical telescopes. The material provides a superior weight to stiffness ratio, which is an important metric for the design and fabrication of lightweight space telescopes. The material also has superior thermal properties with a low coefficient of thermal expansion, and a high thermal conductivity. The thermal properties advantages are important for both space based and ground based systems, which typically need to operate under stressing thermal conditions. The paper will review L-3 Integrated Optical Systems - SSG’s (L-3 SSG) work in developing SiC optics and SiC optical systems for astronomical observing systems. L-3 SSG has been fielding SiC optical components and systems for over 25 years. Space systems described will emphasize the recently launched Long Range Reconnaissance Imager (LORRI) developed for JHU-APL and NASA-GSFC. Review of ground based applications of SiC will include supporting L-3 IOS-Brashear’s current contract to provide the 0.65 meter diameter, aspheric SiC secondary mirror for the Advanced Technology Solar Telescope (ATST).

  10. Steps toward determination of the size and structure of the broad-line region in active galatic nuclei. 8: An intensive HST, IUE, and ground-based study of NGC 5548

    NASA Technical Reports Server (NTRS)

    Korista, K. T.; Alloin, D.; Barr, P.; Clavel, J.; Cohen, R. D.; Crenshaw, D. M.; Evans, I. N.; Horne, K.; Koratkar, A. P.; Kriss, G. A.

    1995-01-01

    We present the data and initial results from a combined Hubble Space Telescope (HST)/IUE/ground-based spectroscopic monitoring campaign on the Seyfert 1 galaxy NGC 5548 that was undertaken in order to address questions that require both higher temporal resolution and higher signal-to-noise ratios than were obtained in our previous multiwavelength monitoring of this galaxy in 1988-1989. IUE spectra were obtained once every 2 days for a period of 74 days beginning on 1993 March 14. During the last 39 days of this campaign, spectroscopic observations were also made with the HST Faint Object Spectrograph (FOS) on a daily basis. Ground-based observations, consisting of 165 optical spectra and 77 photometric observations (both CCD imaging and aperture photometry), are reported for the period 1992 October-1993 September, although many of the data are concentrated around the time of the satellite-based program. These data constitute a fifth year of intensive optical monitoring of this galaxy. In this contribution we describe the acquisition and reduction of all of the satellite and ground-based data obtained in this program. We describe in detail various photometric problems with the FOS and explain how we identified and corrected for various anomalies.

  11. Precursor Analysis for Flight- and Ground-Based Anomaly Risk Significance Determination

    NASA Technical Reports Server (NTRS)

    Groen, Frank

    2010-01-01

    This slide presentation reviews the precursor analysis for flight and ground based anomaly risk significance. It includes information on accident precursor analysis, real models vs. models, and probabilistic analysis.

  12. Flight- and Ground-Based Materials Science Programs at NASA

    NASA Technical Reports Server (NTRS)

    Gillies, Donald C.

    1999-01-01

    The Microgravity Research Division of NASA funds research programs in all branches of materials science including ceramics and glasses. A NASA Research Announcement (NRA)is currently planned with proposals due in March 1999. Proposals are accepted for both flight- definition and ground- based research projects with a main criterion being a strong justification for microgravity. A review of the program in its entirety will be given, with special emphasis on microgravity related ceramics research. The topics of current interest in the NRA will be discussed in terms of International Space Station research and NASA's Human Exploration and Development of Space (HEDS) initiative.

  13. Sky type discrimination using a ground-based sun photometer

    USGS Publications Warehouse

    DeFelice, Thomas P.; Wylie, B.K.

    2001-01-01

    A 2-year feasibility study was conducted at the USGS EROS Data Center, South Dakota (43.733°N, 96.6167°W) to assess whether a four-band, ground-based, sun photometer could be used to discriminate sky types. The results indicate that unique spectral signatures do exist between sunny skies (including clear and hazy skies) and cirrus, and cirrostratus, altocumulus or fair-weather cumulus, and thin stratocumulus or altostratus, and fog/fractostratus skies. There were insufficient data points to represent other cloud types at a statistically significant level.

  14. Report on the ground-based observation campaign of 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Jehin, Emmanuel

    2015-11-01

    Rosetta gets closer to the nucleus than any previous mission, and returns wonderfully detailed measurements from the heart of the comet, but at the cost of not seeing the large scale coma and tails. The ground-based campaign fills in the missing part of the picture, studying the comet at about 1000 km resolution, and following how the overall activity of the comet varies. These data provide context information for Rosetta, so changes in the inner coma seen by the spacecraft can be correlated with the phenomena observable in comets. This will not only help to complete our understanding of the activity of 67P, but also to allow us to compare it with other comets that are only observed from the ground.The ground-based campaign includes observations with nearly all major facilities world-wide. In 2014 the majority of data came from the ESO VLT, as the comet was still relatively faint and in Southern skies, but as it returns to visibility from Earth in 2015 it is considerably brighter, approaching its perihelion in August, and at Northern declinations. I will present results from the 2014 campaign, including visible wavelength photometry and spectroscopy, and the latest results from 2015 observations.

  15. THEMIS Ground Based Observatory System Design

    NASA Astrophysics Data System (ADS)

    Harris, S. E.; Mende, S. B.; Angelopoulos, V.; Rachelson, W.; Donovan, E.; Jackel, B.; Greffen, M.; Russell, C. T.; Pierce, D. R.; Dearborn, D. J.; Rowe, K.; Connors, M.

    2008-12-01

    The comprehensive THEMIS approach to solving the substorm problem calls for monitoring the nightside auroral oval with low-cost, robust white-light imagers and magnetometers that can deliver high time resolution data (0.33 and 2 Hz, respectively). A network of 20 Ground-Based Observatories (GBOs) are deployed across Canada and Alaska to support the collection of data from these instruments. Here we describe the system design of the observatory, with emphasis on how the design meets the environmental and data-collection requirements. We also review the design of the All Sky Imager (ASI), discuss how it was built to survive Arctic deployments, and summarize the optical characterizations performed to qualify the design to meet THEMIS mission requirements.

  16. Augmenting WFIRST Microlensing with a Ground-Based Telescope Network

    NASA Astrophysics Data System (ADS)

    Zhu, Wei; Gould, Andrew

    2016-06-01

    Augmenting the Wide Field Infrared Survey Telescope (WFIRST) microlensing campaigns with intensive observations from a ground-based network of wide-field survey telescopes would have several major advantages. First, it would enable full two-dimensional (2-D) vector microlens parallax measurements for a substantial fraction of low-mass lenses as well as planetary and binary events that show caustic crossing features. For a significant fraction of the free-floating planet (FFP) events and all caustic-crossing planetary/binary events, these 2-D parallax measurements directly lead to complete solutions (mass, distance, transverse velocity) of the lens object (or lens system). For even more events, the complementary ground-based observations will yield 1-D parallax measurements. Together with the 1-D parallaxes from WFIRST alone, they can probe the entire mass range M > M_Earth. For luminous lenses, such 1-D parallax measurements can be promoted to complete solutions (mass, distance, transverse velocity) by high-resolution imaging. This would provide crucial information not only about the hosts of planets and other lenses, but also enable a much more precise Galactic model. Other benefits of such a survey include improved understanding of binaries (particularly with low mass primaries), and sensitivity to distant ice-giant and gas-giant companions of WFIRST lenses that cannot be detected by WFIRST itself due to its restricted observing windows. Existing ground-based microlensing surveys can be employed if WFIRST is pointed at lower-extinction fields than is currently envisaged. This would come at some cost to the event rate. Therefore the benefits of improved characterization of lenses must be weighed against these costs.

  17. Recent Improvements in AMSR2 Ground-Based RFI Filtering

    NASA Astrophysics Data System (ADS)

    Scott, J. P.; Gentemann, C. L.; Wentz, F. J.

    2015-12-01

    Passive satellite radiometer measurements in the microwave frequencies (6-89 GHz) are useful in providing geophysical retrievals of sea surface temperature (SST), atmospheric water vapor, wind speed, rain rate, and more. However, radio frequency interference (RFI) is one of the fastest growing sources of error in these retrievals. RFI can originate from broadcasting satellites, as well as from ground-based instrumentation that makes use of the microwave range. The microwave channel bandwidths used by passive satellite radiometers are often wider than the protected bands allocated for this type of remote sensing, a common practice in microwave radiometer design used to reduce the effect of instrument noise in the observed signal. However, broad channel bandwidths allow greater opportunity for RFI to affect these observations and retrievals. For ground-based RFI, a signal is broadcast directly into the atmosphere which may interfere with the radiometer - its antenna, cold mirror, hot load or the internal workings of the radiometer itself. It is relatively easy to identify and flag RFI from large sources, but more difficult to do so from small, sporadic sources. Ground-based RFI has high spatial and temporal variability, requiring constant, automated detection and removal to avoid spurious trends leaching into the geophysical retrievals. Ascension Island in the South Atlantic Ocean has been one of these notorious ground-based RFI sources, affecting many microwave radiometers, including the AMSR2 radiometer onboard JAXA's GCOM-W1 satellite. Ascension Island RFI mainly affects AMSR2's lower frequency channels (6.9, 7.3, and 10.65 GHz) over a broad spatial region in the South Atlantic Ocean, which makes it challenging to detect and flag this RFI using conventional channel and geophysical retrieval differencing techniques. The authors have developed a new method of using the radiometer's earth counts and hot counts, for the affected channels, to detect an Ascension Island

  18. Ground Based Studies of the Outer Planets

    NASA Technical Reports Server (NTRS)

    Trafton, Laurence M.

    2005-01-01

    This report covers progress to date under this grant on our continuing program to conduct ground based studies of the outer solar system planets and satellites, with emphasis on spectroscopy and atmospheric phenomena. The research continues under our new PAST grant, NNG04G131G beginning 5/1/2004. The original period of performance of the subject grant was 3/1/2001 to 2/28/2004, but was extended one year at no cost. Although there is some overlap in the scientific projects conducted during the extended year with those of the new grant, this report is confined to the portion of the work funded under NAG5-10435. The primary goals for this grant period were a comparative study of outer planet thermospheres/ionospheres near solar maximum, extended to the mid-IR, and the investigation of molecular dimers in outer solar system atmospheres. This project supports NASA's planned space missions, Jupiter Polar Orbiter, outer Planet Microprobes, and the recent Cassini flyby of Jupiter. It also supports the OSS strategic plan themes, The Exploration of the Solar System and The Sun-Earth Connection/ Understanding comparative planetary space environments.

  19. Ground based observations of stratospheric nitrogen dioxide

    NASA Astrophysics Data System (ADS)

    Syed, M. Q.; Harrison, A. W.

    1980-06-01

    The results of ground based measurements of stratospheric NO2, using four different established methods based on twilight sky observations in the spectral region 437.0-451.0 nm and made at two locations: Primrose Lake and at Priddis, Alberta, Canada, during March and April 1979 are presented. It is shown that the four methods differ from one another on the basis of: (a) whether or not stratospheric ozone is taken into account, (b) whether a continuous NO2 absorption spectrum or just the absorption at a few discrete wavelengths is used for analysis, and (c) the assumed altitude distribution of NO2 concentration. Further, two different independently developed altitude distribution models are employed in obtaining the NO2 vertical column abundance and its effective altitude from a set of slant column abundances measured in the twilight sky at different solar zenith angles in the range of 85 to 96 deg. Finally, a comparison shows that the use of one or the other of these two models alone could introduce a difference of as much as 30% in the derived vertical column abundance.

  20. Ground-based observation of near-Earth asteroids

    NASA Astrophysics Data System (ADS)

    Gaffey, Michael J.

    An increased ground-based observation program is an essential component of any serious attempt to assess the resource potential of near-Earth asteroids. A vigorous search and characterization program could lead to the discovery and description of about 400 to 500 near-Earth asteroids in the next 20 years. This program, in conjunction with meteorite studies, would provide the data base to ensure that the results of a small number of asteroid-rendezvous and sample-return missions could be extrapolated with confidence into a geological base map of the Aten, Apollo, and Amor asteroids. Ground-based spectral studies of nearly 30 members of the Aten/Apollo/Amor population provide good evidence that this class includes bodies composed of silicates, metal-silicates, and carbonaceous assemblages similar to those found in meteorites. The instruments that are being used or could be used to search for near-Earth asteroids are listed. Techniques useful in characterizing asteroids and the types of information obtainable using these techniques are listed.

  1. Ground-based observation of near-Earth asteroids

    NASA Technical Reports Server (NTRS)

    Gaffey, Michael J.

    1992-01-01

    An increased ground-based observation program is an essential component of any serious attempt to assess the resource potential of near-Earth asteroids. A vigorous search and characterization program could lead to the discovery and description of about 400 to 500 near-Earth asteroids in the next 20 years. This program, in conjunction with meteorite studies, would provide the data base to ensure that the results of a small number of asteroid-rendezvous and sample-return missions could be extrapolated with confidence into a geological base map of the Aten, Apollo, and Amor asteroids. Ground-based spectral studies of nearly 30 members of the Aten/Apollo/Amor population provide good evidence that this class includes bodies composed of silicates, metal-silicates, and carbonaceous assemblages similar to those found in meteorites. The instruments that are being used or could be used to search for near-Earth asteroids are listed. Techniques useful in characterizing asteroids and the types of information obtainable using these techniques are listed.

  2. Antiradical activity of gallic acid included in lipid interphases.

    PubMed

    Salcedo, C L; Frías, M A; Cutro, A C; Nazareno, M A; Disalvo, E A

    2014-10-01

    Polyphenols are well known as antioxidant agents and by their effects on the hydration layers of lipid interphases. Among them, gallic acid and its derivatives are able to decrease the dipole potential and to act in water as a strong antioxidant. In this work we have studied both effects on lipid interphases in monolayers and bilayers of dimyristoylphosphatidylcholine. The results show that gallic acid (GA) increases the negative surface charges of large unilamellar vesicles (LUVs) and decreases the dipole potential of the lipid interphase. As a result, positively charged radical species such as ABTS(+) are able to penetrate the membrane forming an association with GA. These results allow discussing the antiradical activity (ARA) of GA at the membrane phase which may be taking place in water spaces between the lipids.

  3. Analysis of stratospheric NO2 trends above Kiruna using ground-based zenith sky DOAS observations

    NASA Astrophysics Data System (ADS)

    Gu, Myojeong; Enell, Carl-Fredrik; Hendrick, François; Platt, Ulrich; Pukite, Janis; Raffalski, Uwe; Van Roozendael, Michel; Wagner, Thomas

    2016-04-01

    Stratospheric NO2 not only destroys ozone but acts as a buffer against halogen catalyzed ozone loss by converting halogen species into stable nitrates. To a better understanding of the impacts of stratospheric NO2 and O3 chemistry, we need long-term measurement data. In this study, ground-based zenith sky DOAS has successfully monitored trace gases related to stratospheric ozone chemistry since 1997. In this study, we shows the trend in stratospheric NO2 vertical column densities (VCDs) at Kiruna, Sweden (68.84°N, 20.41°E) as derived from ground-based zenith sky DOAS over the period 1997 to 2015. The results will be compared with satellite data measured from GOME on ERS-2, SCIAMACHY on EnviSAT, and GOME-2 on METOP-A. To calculate the trends, we apply a multiple linear regression model including variables to describe effects caused by the quasi-biennial oscillation (QBO), solar activity, and stratospheric aerosol amount.

  4. Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. 8: An intensive HST, IUE, and ground-based study of NGC 5548

    NASA Technical Reports Server (NTRS)

    Korista, K.; Alloin, D.; Barr, P.; Clavel, J.; Cohen, R. D.; Crenshaw, D. M.; Evans, I. N.; Horne, K.; Koratkar, A. P.; Kriss, G. A.

    1994-01-01

    We present the data and initial results from a combined HST/IUE/ground-based spectroscopic monitoring campaign on the Seyfert 1 galaxy NGC 5548 that was undertaken in order to address questions that require both higher temporal resolution and higher signal-to-noise ratios than were obtained in our previous multiwavelength monitoring of this galaxy in 1988-89. IUE spectra were obtained once every two days for a period of 74 days beginning on 14 March 1993. During the last 39 days of this campaign, spectroscopic observations were also made with the HST Faint Object Spectrograph (FOS) on a daily basis. Ground-based observations, consisting of 165 optical spectra and 77 photometric observations (both CCD imaging and aperture photometry), are reported for the period 1992 October to 1993 September, although much of the data are concentrated around the time of the satellite-based program. These data constitute a fifth year of intensive optical monitoring of this galaxy. In this contribution, we describe the acquisition and reduction of all of the satellite and ground-based data obtained in this program. We describe in detail various photometric problems with the FOS and explain how we identified and corrected for various anomalies. During the HST portion of the monitoring campaign, the 1350 A continuum flux is found to have varied by nearly a factor of two. In other wavebands, the continuum shows nearly identical behavior, except that the amplitude of variability is larger at shorter wavelengths, and the continuum light curves appear to show more short time-scale variability at shorter wavelengths. The broad emission lines also vary in flux, with amplitudes that are slightly smaller than the UV continuum variations and with a small time delay relative to the UV continuum. On the basis of simple time-series analysis of the UV and optical continuum and emission line light curves, we find (1) that the ultraviolet and optical continuum variations are virtually simultaneous

  5. Ground-based research of crystal growth of II-VI compound semiconductors by physical vapor transport

    NASA Technical Reports Server (NTRS)

    Volz, M. P.; Gillies, D. C.; Szofran, F. R.; Lehoczky, S. L.; Su, Ching-Hua; Sha, Yi-Gao; Zhou, W.; Dudley, M.; Liu, Hao-Chieh; Brebrick, R. F.; Wang, J. C.

    1994-01-01

    Ground-based investigation of the crystal growth of II-VI semiconductor compounds, including CdTe, CdS, ZnTe, and ZnSe, by physical vapor transport in closed ampoules was performed. The crystal growth experimental process and supporting activities--preparation and heat treatment of starting materials, vapor partial pressure measurements, and transport rate measurements are reported. The results of crystal characterization, including microscopy, microstructure, optical transmission photoluminescence, synchrotron radiation topography, and chemical analysis by spark source mass spectrography, are also discussed.

  6. Telerobotic manipulator developments for ground-based space research

    NASA Technical Reports Server (NTRS)

    Herndon, J. N.; Babcock, S. M.; Butler, P. L.; Costello, H. M.; Glassell, R. L.; Kress, Reid L.; Kuban, D. P.; Rowe, J. C.; Williams, D. M.; Meintel, A. J.

    1988-01-01

    New opportunities for the application of telerobotic systems to enhance human intelligence and dexterity in the hazardous environment of space are presented by the National Aeronautics and Space Administration (NASA) Space Station Program. Because of the need for significant increases in extravehicular activity and the potential increase in hazards associated with space programs, emphasis is being heightened on telerobotic systems research and development. The Automation Technology Branch at NASA Langley Research Center currently is sponsoring the Laboratory Telerobotic Manipulator (LTM) program at Oak Ridge National Laboratory to develop and demonstrate ground-based telerobotic manipulator system hardware for research and demonstrations aimed at future NASA applications. The LTM incorporates traction drives, modularity, redundant kinematics, and state-of-the-art hierarchical control techniques to form a basis for merging the diverse technological domains of robust, high-dexterity teleoperations and autonomous robotic operation into common hardware to further NASA's research.

  7. Current trends in ground based solar magnetometry

    NASA Astrophysics Data System (ADS)

    Gosain, Sanjay

    2016-07-01

    Continuous observations of the sun, over more than a century, have led to several important discoveries in solar astronomy. These include the discovery of the solar magnetism and its cyclic modulation, active region formation and decay and their role in energetic phenomena such as fares and coronal mass ejections (CMEs), fine structure and dynamics of the sunspots and small-scale organization of the magnetic flux in the form of flux tubes and so forth. In this article we give a brief overview of advancements in solar observational techniques in recent decades and the results obtained from the such observations. These include techniques to achieve high angular resolution, high spectral and polarimetric sensitivity and innovative new detectors. A wide range of spatial, temporal and spectral domains exploited by solar astronomers to understand the solar phenomena are discussed. Many new upcoming telescopes and instruments that are designed to address different aspects of solar physics problems are briefly described. Finally, we discuss the advantages of observing from the ground and how they can complement space-based observations.

  8. Ground-Based Thermal Imaging of Coastal and Riverine Sediments

    NASA Astrophysics Data System (ADS)

    Sliwinski, T.; McKenna, T. E.; Puleo, J. A.; Meehan, C. L.

    2010-12-01

    Ground-based remote sensing can provide information on spatio-temporal distributions of sediment and geotechnical properties in dynamic coastal and riverine environments where it can be difficult to collect representative in-situ data. The spatio-temporal variability of grain size, moisture content and biological activity in these environments presents a major challenge in the development of robust remote sensing applications. For ground-based thermal imaging, the radiation received by the imager is a function of the temperature and emissivity of the sediment, observation geometry, atmospheric transmittance (distance and humidity), and reflected background radiation. This study examines the effects of observation geometry on emissivity and the apparent temperature of sediments. A bench-scale multi-spectral imaging system was developed to assess the effects of viewing angle, heating/cooling and moisture variation on thermal imager response. Preliminary results show the expected decrease in emissivity with increasing view angle. Our goal is to parameterize this effect so that imagery from uncontrolled field conditions can be corrected. Combined with corrections for atmospheric transmittance and reflected radiation and an emissivity separation routine, this will allow for a more accurate evaluation of spatio-temporal variations in surface temperature and enable evaluation of the heat-transfer processes driving temporal variations. Of primary interest is estimating the thermal and hydraulic properties of the sediment which serve as proxies for grain size, porosity and moisture content (fundamental parameters for geotechnical applications). This is facilitated using a numerical model that couples heat transfer in the subsurface and atmosphere and allows for periodic inundation with surface water. Results from laboratory experiments and a recent field study on a sandy beach along the Wolf River in Mississippi will be presented.

  9. Optimal design of active and semi-active suspensions including time delays and preview

    NASA Astrophysics Data System (ADS)

    Hac', A.; Youn, I.

    1993-10-01

    Several control laws for active and semi-active suspension based on a linear half car model are derived and investigated. The strategies proposed take full advantage of the fact that the road input to the rear wheels is a delayed version of that to the front wheels, which in turn can be obtained either from the measurements of the front wheels and body motions or by direct preview of road irregularities if preview sensors are available. The suspension systems are optimized with respect to ride comfort, road holding and suspension rattle space as expressed by the mean-square-values of body acceleration (including effects of heave and pitch), tire deflections and front and rear suspension travels. The optimal control laws that minimize the given performance index and include passivity constraints in the semi-active case are derived using calculus of variation. The optimal semi-active suspension becomes piecewise linear, varying between passive and fully active systems and combinations of them. The performances of active and semi-active systems with and without preview were evaluated by numerical simulation in the time and frequency domains. The results show that incorporation of time delay between the front and rear axles in controller design improves the dynamic behavior of the rear axle and control of body pitch motion, while additional preview improves front wheel dynamics and body heave.

  10. Space-borne detection of volcanic carbon dioxide anomalies: The importance of ground-based validation networks

    NASA Astrophysics Data System (ADS)

    Schwandner, F. M.; Carn, S. A.; Corradini, S.; Merucci, L.; Salerno, G.; La Spina, A.

    2012-04-01

    We have investigated the feasibility of space-borne detection of volcanic carbon dioxide (CO2) anomalies, and their integration with ground-based observations. Three goals provide motivation to their integration: (a) development of new volcano monitoring techniques, with better spatial and temporal coverage, because pre-eruptive volcanic CO2 emissions are potentially the earliest available indicators of volcanic unrest; (b) improvement the currently very poor global CO2 source strength inventory for volcanoes, and (c) use of volcanic CO2 emissions for high altitude strong point source emission and dispersion studies. (1) Feasibility of space-borne detection of volcanic CO2 anomalies. Volcanoes are highly variable but continuous CO2 emitters, distributed globally, and emissions often occur at high altitudes. To detect strong point sources of CO2 from space, several hurdles have to be overcome: orographic clouds, unknown dispersion behavior, a high CO2 background in the troposphere, and sparse data coverage from existing satellite sensors. These obstacles can be overcome by a small field of view, enhanced spectral resolving power, and by employing repeat target mode observation strategies. The Japanese GOSAT instrument has been operational since January 2009, producing CO2 total column measurements with a repeat cycle of 3 days and a field of view of 10km. GOSAT thus has the potential to provide spatially integrated data for entire volcanic edifices, especially in target mode. Since summer 2010 we have conducted repeated target mode observations of over 20 persistently active global volcanoes including Etna (Italy), Erta Ale (Ethiopia), and Ambrym (Vanuatu), using L2 GOSAT FTS SWIR data. One of our best-studied test cases is Mt. Etna on Sicily (Italy), which reawakened in 2011 after a period of quiescence and produced a sequence of eruptive activities including lava fountaining events, coinciding with target-mode GOSAT observations conducted there since 2010. For the

  11. Progress report of FY 1997 activities: The application of Kalman filtering to derive water vapor profiles from combined ground-based sensors: Raman lidar, microwave radiometers, GPS, and radiosondes

    SciTech Connect

    Edgeworth R. Westwater; Yong Han

    1997-10-05

    Previously, the proposers have delivered to ARM a documented algorithm, that is now applied operationally, and which derives water vapor profiles from combined remote sensor measurements of water vapor radiometers, cloud-base ceilometers, and radio acoustic sounding systems (RASS). With the expanded deployment of a Raman lidar at the CART Central Facility, high quality, high vertical-resolution, water vapor profiles will be provided during nighttime clear conditions, and during clear daytime conditions, to somewhat lower altitudes. The object of this proposal was to use Kalman Filtering, previously applied to the combination of nighttime Raman lidar and microwave radiometer data, to derive high-quality water vapor profiles, during non-precipitating conditions, from data routinely available at the CART site. Input data to the algorithm would include: Raman lidar data, highly quality-controlled data of integrated moisture from microwave radiometers and GPS, RASS, and radiosondes. The algorithm will include recently-developed quality control procedures for radiometers. The focus of this years activities has been on the intercomparison of data obtained during an intensive operating period at the SGP CART site in central Oklahoma.

  12. Extragalactic Science with the Next Generation of Ground Based TeV {gamma}-Ray Telescopes

    SciTech Connect

    Krawczynski, Henric

    2008-12-24

    The ground based Cherenkov telescope experiments H.E.S.S., MAGIC, and VERITAS, and the space borne Fermi Gamma-Ray Space Telescope are currently exploring the galactic and extragalactic Universe in {gamma}-rays. At the time of writing this article, a large number of Active Galactic Nuclei have been studied in great detail and the {gamma}-ray observations have had a major impact on our understanding of the structure of jets from these objects. In this contribution, the status of ground based {gamma}-ray observations of AGN and other extragalactic source classes is reviewed as of October, 2008. After discussing source classes that could be detected with next generation ground based experiments like AGIS, CTA, and HAWC, the potential impact of the observations on the fields of high energy astrophysics, structure formation, observational cosmology, and fundamental physics is reviewed. We close with a discussion of the technical requirements that arise from the science drivers.

  13. Interpretation of ground-based microwave measurements of the moon using a detailed regolith properties model

    NASA Technical Reports Server (NTRS)

    Gary, B. L.; Keihm, S. J.

    1978-01-01

    A detailed model for the regolith's thermophysical and microwave properties has been used for the interpretation of ground-based measurements of the moon's microwave brightness temperature variation with lunar phase and changes during eclipses. The ground-based measurements include some crucial new lunation variation observations at 2.8, 6.0 and 13.1 cm. The many parameters in the regolith properties model were assigned values based on a careful review of Apollo in situ and lab sample measurements of thermophysical and electrical properties. The first identification of a wavelength-dependent component of scattering is reported.

  14. Space transfer with ground-based laser/electric propulsion

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Stavnes, Mark; Oleson, Steve; Bozek, John

    1993-01-01

    A new method of providing power to space vehicles consists of using ground-based lasers to beam power to photovoltaic receivers in space. This can be used as a power source for electrically propelled orbital transfer vehicles.

  15. Progress report of FY 1998 activities: The application of Kalman filtering to derive water vapor profiles from combined ground-based sensors: Raman lidar, microwave radiometers, GPS, and radiosondes

    SciTech Connect

    Edgeworth R. Westwater; Yong Han

    1999-10-01

    Previously, the proposers have delivered to ARM a documented algorithm, that is now applied operationally, and which derives water vapor profiles from combined remote sensor measurements of water vapor radiometers, cloud-base ceilometers, and radio acoustic sounding systems (RASS). With the expanded deployment of a Raman lidar at the CART Central Facility, high quality, high vertical-resolution, water vapor profiles will be provided during nighttime clear conditions, and during clear daytime conditions, to somewhat lower altitudes. The object of this effort is to use Kalman Filtering, previously applied to the combination of nighttime Raman lidar and microwave radiometer data, to derive high-quality water vapor profiles, during non-precipitating conditions, from data routinely available at the CART site. Input data to the algorithm would include: Raman lidar data, highly quality-controlled data of integrated moisture from microwave radiometers and GPS, RASS, and radiosondes. The focus of this years activities has been on the intercomparison of data obtained during the Water Vapor Intensive Operating Period'97 at the SGP CART site in central Oklahoma.

  16. Challenges and Opportunities for Ground-based Helioseismic Observations

    NASA Astrophysics Data System (ADS)

    Chaplin, W. J.

    2013-12-01

    I summarize the current status of ground-based helioseismic observations, in particular the two operational networks GONG and BiSON. I then discuss requirements for continued and future ground-based observations based on key science drivers, finishing with a discussion of SPRING, a proposed future high-spatial-resolution network that would provide helioseismic data and a broad range of synoptic data products.

  17. Predicting thunderstorm evolution using ground-based lightning detection networks

    NASA Technical Reports Server (NTRS)

    Goodman, Steven J.

    1990-01-01

    Lightning measurements acquired principally by a ground-based network of magnetic direction finders are used to diagnose and predict the existence, temporal evolution, and decay of thunderstorms over a wide range of space and time scales extending over four orders of magnitude. The non-linear growth and decay of thunderstorms and their accompanying cloud-to-ground lightning activity is described by the three parameter logistic growth model. The growth rate is shown to be a function of the storm size and duration, and the limiting value of the total lightning activity is related to the available energy in the environment. A new technique is described for removing systematic bearing errors from direction finder data where radar echoes are used to constrain site error correction and optimization (best point estimate) algorithms. A nearest neighbor pattern recognition algorithm is employed to cluster the discrete lightning discharges into storm cells and the advantages and limitations of different clustering strategies for storm identification and tracking are examined.

  18. Ground-based Observations of the Solar Sources of Space Weather

    NASA Astrophysics Data System (ADS)

    Veronig, A. M.; Pötzi, W.

    2016-04-01

    Monitoring of the Sun and its activity is a task of growing importance in the frame of space weather research and awareness. Major space weather disturbances at Earth have their origin in energetic outbursts from the Sun: solar flares, coronal mass ejections and associated solar energetic particles. In this review we discuss the importance and complementarity of ground-based and space-based observations for space weather studies. The main focus is drawn on ground-based observations in the visible range of the spectrum, in particular in the diagnostically manifold Hα spectral line, which enables us to detect and study solar flares, filaments (prominences), filament (prominence) eruptions, and Moreton waves. Existing Hα networks such as the GONG and the Global High-Resolution Hα Network are discussed. As an example of solar observations from space weather research to operations, we present the system of real-time detection of Hα flares and filaments established at Kanzelhöhe Observatory (KSO; Austria) in the frame of the space weather segment of the ESA Space Situational Awareness programme (swe.ssa.esa.int). An evaluation of the system, which is continuously running since July 2013 is provided, covering an evaluation period of almost 2.5 years. During this period, KSO provided 3020 hours of real-time Hα observations at the ESA SWE portal. In total, 824 Hα flares were detected and classified by the real-time detection system, including 174 events of Hα importance class 1 and larger. For the total sample of events, 95 % of the automatically determined flare peak times lie within ±5 min of the values given in the official optical flares reports (by NOAA and KSO), and 76 % of the start times. The heliographic positions determined are better than ±5°. The probability of detection of flares of importance 1 or larger is 95 %, with a false alarm rate of 16 %. These numbers confirm the high potential of automatic flare detection and alerting from ground-based

  19. Ground-Based Research within NASA's Materials Science Program

    NASA Technical Reports Server (NTRS)

    Gillies, Donald C.; Curreri, Peter (Technical Monitor)

    2002-01-01

    Ground-based research in Materials Science for NASA's Microgravity program serves several purposes, and includes approximately four Principal Investigators for every one in the flight program. While exact classification is difficult. the ground program falls roughly into the following categories: (1) Intellectual Underpinning of the Flight Program - Theoretical Studies; (2) Intellectual Underpinning of the Flight Program - Bringing to Maturity New Research; (3) Intellectual Underpinning of the Flight Program - Enabling Characterization; (4) Intellectual Underpinning of the Flight Program - Thermophysical Property Determination; (5) Radiation Shielding; (6) Preliminary In Situ Resource Utilization; (7) Biomaterials; (8) Nanostructured Materials; (9) Materials Science for Advanced Space Propulsion. It must be noted that while the first four categories are aimed at using long duration low gravity conditions, the other categories pertain more to more recent NASA initiatives in materials science. These new initiatives address NASA's future materials science needs in the realms of crew health and safety, and exploration, and have been included in the most recent NASA Research Announcements (NRA). A description of each of these nine categories will be given together with examples of the kinds of research being undertaken.

  20. Adrenocorticotrophic Hormone Levels in Ground Based Studies

    NASA Technical Reports Server (NTRS)

    Campbell, B. O.

    1972-01-01

    Baseline values of immunoreactive ACTH were established in the normal healthy adult. Normal levels of ACTH secretion were determined for both the male and the female in circulating plasma and serum. The data obtained in these studies are particularly significant in that the sampling was carefully controlled; only healthy employed individuals of both sexes were tested in a routine work situation that would not be considered conducive to stress. It has been found that alterations in the classically described circadian rhythm of ACTH secretion can occur when activities (such as work/rest cycles) are imposed on the individual studied. These changes can be demonstrated even when there is no appreciable change noted in the rhythm of hydrocortisone secretion.

  1. Future enhancements to ground-based microburst detection

    NASA Technical Reports Server (NTRS)

    Campbell, Steven D.; Matthews, Michael P.; Dasey, Timothy J.

    1994-01-01

    This set of viewgraphs presents the results of the Cockpit Weather Information (CWI) program at M.I.T. Lincoln Laboratory. The CWI program has been funded through NaSA Langley Research Center by the joint NASA/FAA Integrated Airborne Wind Shear Program for the past four years. During this time, over 120 microburst penetrations by research aircraft have been conducted under Terminal Doppler Weather Radar (TDWR) testbed radar surveillance at Orlando, FL. The results of these in-situ measurements have been compared with ground-based detection methods. Several valuable insights were gained from this research activity. First, it was found that the current TDWR microburst shapes do not permit accurate characterization of microburst hazard in terms of the F factor hazard index, because they are based on loss value rather than shear. Second, it was found that the horizontal component of the F factor can be accurately estimated from shear, provided compensation is made for the dependence of outflow strength on altitude. Third, it was found that a simple continuity assumption for estimating the vertical component of the F factor yielded poor results. However, further research has shown that downdraft strength is correlated with features aloft detected by the TDWR radar scan strategy. The outcome of the CWI program is to move from the loss-based wind shear detection algorithm used in the TDWR to a shear-based detection scheme as proposed in the Integrated Terminal Weather System (ITWS).

  2. Simulating the Performance of Ground-Based Optical Asteroid Surveys

    NASA Astrophysics Data System (ADS)

    Christensen, Eric J.; Shelly, Frank C.; Gibbs, Alex R.; Grauer, Albert D.; Hill, Richard E.; Johnson, Jess A.; Kowalski, Richard A.; Larson, Stephen M.

    2014-11-01

    We are developing a set of asteroid survey simulation tools in order to estimate the capability of existing and planned ground-based optical surveys, and to test a variety of possible survey cadences and strategies. The survey simulator is composed of several layers, including a model population of solar system objects and an orbital integrator, a site-specific atmospheric model (including inputs for seeing, haze and seasonal cloud cover), a model telescope (with a complete optical path to estimate throughput), a model camera (including FOV, pixel scale, and focal plane fill factor) and model source extraction and moving object detection layers with tunable detection requirements. We have also developed a flexible survey cadence planning tool to automatically generate nightly survey plans. Inputs to the cadence planner include camera properties (FOV, readout time), telescope limits (horizon, declination, hour angle, lunar and zenithal avoidance), preferred and restricted survey regions in RA/Dec, ecliptic, and Galactic coordinate systems, and recent coverage by other asteroid surveys. Simulated surveys are created for a subset of current and previous NEO surveys (LINEAR, Pan-STARRS and the three Catalina Sky Survey telescopes), and compared against the actual performance of these surveys in order to validate the model’s performance. The simulator tracks objects within the FOV of any pointing that were not discovered (e.g. too few observations, too trailed, focal plane array gaps, too fast or slow), thus dividing the population into “discoverable” and “discovered” subsets, to inform possible survey design changes. Ongoing and future work includes generating a realistic “known” subset of the model NEO population, running multiple independent simulated surveys in coordinated and uncoordinated modes, and testing various cadences to find optimal strategies for detecting NEO sub-populations. These tools can also assist in quantifying the efficiency of novel

  3. Characterizing GEO Titan Transtage Fragmentations using Ground-based Measurements

    NASA Technical Reports Server (NTRS)

    Cowardin, H.; Anz-Meador, P.

    2016-01-01

    In a continued effort to better characterize the Geosynchronous Orbit (GEO) environment, NASA's Orbital Debris Program Office (ODPO) utilizes various ground-based optical assets to acquire photometric and spectral data of known debris associated with fragmentations in or near GEO. The Titan IIIC Transtage upper stage is known to have fragmented four times. Two of the four fragmentations were in GEO while a third Transtage fragmented in GEO transfer orbit. The forth fragmentation occurred in Low Earth Orbit. In order to better assess what may be causing these fragmentations, the NASA ODPO recently acquired a Titan Transtage test and display article that was previously in the custody of the 309th Aerospace Maintenance and Regeneration Group (AMARG) in Tucson, Arizona. After initial inspections at AMARG demonstrated that the test article was of sufficient fidelity to be of interest, the test article was brought to JSC to continue material analysis and historical documentation of the Titan Transtage. The Transtage will be a subject of forensic analysis using spectral measurements to compare with telescopic data; as well, a scale model will be created to use in the Optical Measurement Center for photometric analysis of an intact Transtage, including a BRDF. The following presentation will provide a review of the Titan Transtage, the current analysis that has been done to date, and the future work to be completed in support of characterizing the GEO and near GEO orbital debris environment.

  4. Time series inversion of spectra from ground-based radiometers

    NASA Astrophysics Data System (ADS)

    Christensen, O. M.; Eriksson, P.

    2013-07-01

    Retrieving time series of atmospheric constituents from ground-based spectrometers often requires different temporal averaging depending on the altitude region in focus. This can lead to several datasets existing for one instrument, which complicates validation and comparisons between instruments. This paper puts forth a possible solution by incorporating the temporal domain into the maximum a posteriori (MAP) retrieval algorithm. The state vector is increased to include measurements spanning a time period, and the temporal correlations between the true atmospheric states are explicitly specified in the a priori uncertainty matrix. This allows the MAP method to effectively select the best temporal smoothing for each altitude, removing the need for several datasets to cover different altitudes. The method is compared to traditional averaging of spectra using a simulated retrieval of water vapour in the mesosphere. The simulations show that the method offers a significant advantage compared to the traditional method, extending the sensitivity an additional 10 km upwards without reducing the temporal resolution at lower altitudes. The method is also tested on the Onsala Space Observatory (OSO) water vapour microwave radiometer confirming the advantages found in the simulation. Additionally, it is shown how the method can interpolate data in time and provide diagnostic values to evaluate the interpolated data.

  5. Time series inversion of spectra from ground-based radiometers

    NASA Astrophysics Data System (ADS)

    Christensen, O. M.; Eriksson, P.

    2013-02-01

    Retrieving time series of atmospheric constituents from ground-based spectrometers often requires different temporal averaging depending on the altitude region in focus. This can lead to several datasets existing for one instrument which complicates validation and comparisons between instruments. This paper puts forth a possible solution by incorporating the temporal domain into the maximum a posteriori (MAP) retrieval algorithm. The state vector is increased to include measurements spanning a time period, and the temporal correlations between the true atmospheric states are explicitly specified in the a priori uncertainty matrix. This allows the MAP method to effectively select the best temporal smoothing for each altitude, removing the need for several datasets to cover different altitudes. The method is compared to traditional averaging of spectra using a simulated retrieval of water vapour in the mesosphere. The simulations show that the method offers a significant advantage compared to the traditional method, extending the sensitivity an additional 10 km upwards without reducing the temporal resolution at lower altitudes. The method is also tested on the OSO water vapour microwave radiometer confirming the advantages found in the simulation. Additionally, it is shown how the method can interpolate data in time and provide diagnostic values to evaluate the interpolated data.

  6. Observing Tsunamis in the Ionosphere Using Ground Based GPS Measurements

    NASA Technical Reports Server (NTRS)

    Galvan, D. A.; Komjathy, A.; Song, Y. Tony; Stephens, P.; Hickey, M. P.; Foster, J.

    2011-01-01

    Ground-based Global Positioning System (GPS) measurements of ionospheric Total Electron Content (TEC) show variations consistent with atmospheric internal gravity waves caused by ocean tsunamis following recent seismic events, including the Tohoku tsunami of March 11, 2011. We observe fluctuations correlated in time, space, and wave properties with this tsunami in TEC estimates processed using JPL's Global Ionospheric Mapping Software. These TEC estimates were band-pass filtered to remove ionospheric TEC variations with periods outside the typical range of internal gravity waves caused by tsunamis. Observable variations in TEC appear correlated with the Tohoku tsunami near the epicenter, at Hawaii, and near the west coast of North America. Disturbance magnitudes are 1-10% of the background TEC value. Observations near the epicenter are compared to estimates of expected tsunami-driven TEC variations produced by Embry Riddle Aeronautical University's Spectral Full Wave Model, an atmosphere-ionosphere coupling model, and found to be in good agreement. The potential exists to apply these detection techniques to real-time GPS TEC data, providing estimates of tsunami speed and amplitude that may be useful for future early warning systems.

  7. Ground Based Studies of Thermocapillary Flows in Levitated Drops

    NASA Technical Reports Server (NTRS)

    Sadhal, Satwindar Singh; Trinh, Eugene H.

    1996-01-01

    Ground-based experiments together with analytical studies are presently being conducted for levitated drops. Both acoustic and electrostatic techniques are being employed to achieve levitation of drops in a gaseous environment. The scientific effort is principally on the thermal and the fluid phenomena associated with the local heating of levitated drops, both at 1-g and at low-g. In particular, the thermocapillary flow associated with local spot heating is being studied. Fairly stable acoustic levitation of drops has been achieved with some exceptions when random rotational motion of the drop persists. The flow visualization has been carried out by light scattering from smoke particles for the exterior flow and fluorescent tracer particles in the drop. The results indicate a lack of axial symmetry in the internal flow even though the apparatus and the heating are symmetric. The theoretical studies for the past year have included fundamental analyses of acoustically levitated spherical drops. The flow associated with a particle near the velocity antinode is being investigated by the singular perturbation technique. As a first step towards understanding the effect of the particle displacement from the antinode, the flow field about the node has been calculated for the first time. The effect of the acoustic field on the interior of a liquid drop has also been investigated. The results predict that the internal flow field is very weak.

  8. Detecting Exoplanet Atmospheres from 2-m Ground-Based Telescopes

    NASA Astrophysics Data System (ADS)

    Hall, Shannon; Jang-Condell, H.; Lopez-Morales, M.; Kobulnicky, H. A.; Runnoe, J. C.

    2013-01-01

    The field of exoplanet atmospheric research is quickly expanding. Exoplanet atmospheres are difficult to detect in transmission because their signatures are so small compared to the light coming from the star during transit. However, by comparing observations of the superimposed exoplanet during transit to observations of the star alone, the planet's transmission spectrum may be obtained. We selected the hot Jupiter Kepler-4b and made observations of its host star during primary transits using the long-slit spectrograph at the 2.3m Wyoming Infrared Observatory (WIRO). We used an 1800 l/mm grating which covered a wavelength range from approximately 5400 to 6800 angstroms. The slit was oriented to include a well-known comparison star of similar brightness, located 60 arcseconds away. The spectrum of this comparison star may be used to perform differential spectroscopy with the target spectrum. This minimizes atmospheric variations and helps to normalize the spectrum, reducing it to Poisson noise only. Absorption features seen only during transit can be attributed to the atmosphere of the planet. We will present preliminary data demonstrating the feasibility of detecting exoplanet atmospheres from medium-sized ground-based telescopes.

  9. Three Years of Ground-based Thermal Monitoring at Kilauea

    NASA Astrophysics Data System (ADS)

    Harris, A. J.; Johnson, J. B.; Pirie, D.; Horton, K.; Flynn, L.; Garbeil, H.; Ramm, H.; Pilger, E.

    2003-12-01

    Three permanent ground-based infrared (8 to 14 micron) radiometers, located on Pu'u 'O'o's north crater rim, have provided continuous real-time monitoring of activity within Pu'u 'O'o since March 2001. Our thermal sensors are able to detect lava flows, catastrophic changes in crater floor morphology, and variations in the style and vigor of volcanic degassing. These continuous, long-term thermal observations, integrated with RSAM and tilt measurements, provide an opportunity to investigate the changing nature of systemic activity at Kilauea. For example, our thermal sensors are able to detect periods of lava effusion on the crater floor, coincident with the termination of the rootless shield to the east and subsequent back-up into Pu'u O'o, before activity transitioned to the Mother's Day flow field. Since June 2001, at least one radiometer has been continuously aimed at the central pit vent of Pu'u O'o, whose thermal record has been dominated by regular gas jetting events, typically referred to as gas pistoning. These events are very often observed in the thermal records, indicating that they are a dominant mode of degassing at Kilauea. During June and July of 2000, gas pistoning from the central pit vent occurred with fundamental recurrence intervals of about 2 to 10 minutes, but since October has slowed to less frequent 20 to 40 minute intervals. We propose that the variation in piston frequency is related to dramatic changes in the geometry of the underground plumbing system at Pu'u 'O'o. Currently thermal monitoring of two individual vents, which are separated by ~100 m, provides evidence for linked degassing, further demonstrating the complex and ephemeral nature of the plumbing system beneath Pu'u 'O'o's crater floor.

  10. Ground-based visual guidance in autonomous UAV landing

    NASA Astrophysics Data System (ADS)

    Zhang, Yu; Shen, Lincheng; Cong, Yirui; Zhou, Dianle; Zhang, Daibing

    2013-12-01

    Visual guidance has attracted more and more attention in the navigation field thanks to its accuracy and robustness. This paper presents a ground-based visual guidance system for the autonomous Unmanned Aerial Vehicles (UAV) landing. The system consists of two cameras and pan-tilt units (PTU) that mounted on both sides of the runway. In this system, computer vision is adopted for UAV detection and tracking. To be more specific, triangulation, a geometric method in binocular vision, is employed to calculate the 3D coordinates of the UAV in order to provide landing guidance parameters and finally achieve autonomous UAV landing. The 3D positioning principles adopted in ground-based measurement are simulated and verified. The results show that the accuracy can be achieved and relevant requirements are satisfied by ground-based visual guidance.

  11. Ground-based and satellite observations of substorm onset features

    NASA Astrophysics Data System (ADS)

    Chang, T.; Cheng, C. Z.; Chiang, C.; Tam, S. W.; Chen, A. B.; Hsu, R.; Su, H.

    2009-12-01

    We present the ground-based and satellite observations of substorm onset events. In the observations from Ground Based Observatories (GBO) and the ISUAL/FORMOSAT-2 satellite, we find structures which consist of periodic bright spots on the auroral arc prior to the substorm expansion phase onset. The intensity of arc grows exponentially before breakup with a linear growth rate of ~O(1-3)sec-1. Under the arc, the negative H-bay associated with the substorm is evident in the ground-based magnetometer data. From ISUAL observations, the first auroral brightening is identified roughly at the beginning of the negative H-bay. The auroral arc is breaks up before dispersionless particle injections are observed at geosynchronous orbit. Based on analysis of these observations, we suggest that this event can be a support of the scenario of substorm onset which is caused by a kinetic ballooning instability which is localized at ~ -10RE.

  12. Ground Base Skylab Electron Beam Welds in Tantalum

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Comparison of ground-based (left) and Skylab (right) electron beam welds in pure tantalum (Ta) (10X magnification). Residual votices left behind in the ground-based sample after the electron beam passed were frozen into the grain structure. These occurred because of the rapid cooling rate at the high temperature. Although the thermal characteristics and electron beam travel speeds were comparable for the skylab sample, the residual vortices were erased in the grain structure. This may have been due to the fact that final grain size of the solidified material was smaller in the Skylab sample compared to the ground-based sample. The Skylab sample was processed in the M512 Materials Processing Facility (MPF) during Skylab SL-2 Mission. Principal Investigator was Richard Poorman.

  13. Preparatory study of a ground-based space radiobiology program in Europe

    NASA Astrophysics Data System (ADS)

    Durante, M.; Kraft, G.; O'Neill, P.; Reitz, G.; Sabatier, L.; Schneider, U.

    Space radiation has long been acknowledged as a potential showstopper for long duration manned interplanetary missions. Our knowledge of biological effects of cosmic radiation in deep space is almost exclusively derived from ground-based accelerator experiments with heavy ions in animal or in vitro models. In an effort to gain more information on space radiation risk and to develop countermeasures, NASA initiated several years ago a Space Radiation Health Program, which is currently supporting biological experiments performed at the Brookhaven National Laboratory. Accelerator-based radiobiology research in the field of space radiation research is also under way in Russia and Japan. The European Space Agency (ESA) has recently established an ambitious exploration program (AURORA), and within this program it has been decided to include a space radiation research program. Europe has a long tradition in radiobiology research at accelerators, generally focussing on charged-particle cancer therapy. This expertise can be adapted to address the issue of space radiation risk. To support research in this field in Europe, ESA issued a call for tender in 2005 for a preliminary study of investigations on biological effects of space radiation (IBER). This study will provide guidance on future ESA-supported activities in space radiation research by identifying the most appropriate European accelerator facilities to be targeted for cooperation, and by drafting a roadmap for future research activities. The roadmap will include a prioritisation of research topics, and a detailed proposal for experimental campaigns for the following 5 10 years.

  14. Exoplanets -New Results from Space and Ground-based Surveys

    NASA Astrophysics Data System (ADS)

    Udry, Stephane

    The exploration of the outer solar system and in particular of the giant planets and their environments is an on-going process with the Cassini spacecraft currently around Saturn, the Juno mission to Jupiter preparing to depart and two large future space missions planned to launch in the 2020-2025 time frame for the Jupiter system and its satellites (Europa and Ganymede) on the one hand, and the Saturnian system and Titan on the other hand [1,2]. Titan, Saturn's largest satellite, is the only other object in our Solar system to possess an extensive nitrogen atmosphere, host to an active organic chemistry, based on the interaction of N2 with methane (CH4). Following the Voyager flyby in 1980, Titan has been intensely studied from the ground-based large telescopes (such as the Keck or the VLT) and by artificial satellites (such as the Infrared Space Observatory and the Hubble Space Telescope) for the past three decades. Prior to Cassini-Huygens, Titan's atmospheric composition was thus known to us from the Voyager missions and also through the explorations by the ISO. Our perception of Titan had thus greatly been enhanced accordingly, but many questions remained as to the nature of the haze surrounding the satellite and the composition of the surface. The recent revelations by the Cassini-Huygens mission have managed to surprise us with many discoveries [3-8] and have yet to reveal more of the interesting aspects of the satellite. The Cassini-Huygens mission to the Saturnian system has been an extraordinary success for the planetary community since the Saturn-Orbit-Insertion (SOI) in July 2004 and again the very successful probe descent and landing of Huygens on January 14, 2005. One of its main targets was Titan. Titan was revealed to be a complex world more like the Earth than any other: it has a dense mostly nitrogen atmosphere and active climate and meteorological cycles where the working fluid, methane, behaves under Titan conditions the way that water does on

  15. Ground-Based Observations of Terrestrial Gamma-Ray Flashes

    NASA Astrophysics Data System (ADS)

    Ringuette, R. A.; Cannady, N.; Case, G. L.; Cherry, M. L.; Granger, D.; Isbert, J.; Stewart, M.

    2010-10-01

    First seen from space by the BATSE gamma ray telescope in the 1990s, Terrestrial Gamma ray Flashes (TGFs) consist of extremely fast bursts of high energy (up to 40 MeV) gamma rays correlated with intense lightning from thunderstorms. Spacecraft experiments are sensitive to very large events, but ground-based detectors closer to the thunderstorms may provide data on the intensity spectrum of smaller events. Four detectors consisting of NaI scintillators viewed by photomultipliers have been placed on rooftops at LSU's Baton Rouge campus to monitor TGFs. The setup and design of the ground-based experiment will be discussed.

  16. A Fast Method for Embattling Optimization of Ground-Based Radar Surveillance Network

    NASA Astrophysics Data System (ADS)

    Jiang, H.; Cheng, H.; Zhang, Y.; Liu, J.

    A growing number of space activities have created an orbital debris environment that poses increasing impact risks to existing space systems and human space flight. For the safety of in-orbit spacecraft, a lot of observation facilities are needed to catalog space objects, especially in low earth orbit. Surveillance of Low earth orbit objects are mainly rely on ground-based radar, due to the ability limitation of exist radar facilities, a large number of ground-based radar need to build in the next few years in order to meet the current space surveillance demands. How to optimize the embattling of ground-based radar surveillance network is a problem to need to be solved. The traditional method for embattling optimization of ground-based radar surveillance network is mainly through to the detection simulation of all possible stations with cataloged data, and makes a comprehensive comparative analysis of various simulation results with the combinational method, and then selects an optimal result as station layout scheme. This method is time consuming for single simulation and high computational complexity for the combinational analysis, when the number of stations increases, the complexity of optimization problem will be increased exponentially, and cannot be solved with traditional method. There is no better way to solve this problem till now. In this paper, target detection procedure was simplified. Firstly, the space coverage of ground-based radar was simplified, a space coverage projection model of radar facilities in different orbit altitudes was built; then a simplified objects cross the radar coverage model was established according to the characteristics of space objects orbit motion; after two steps simplification, the computational complexity of the target detection was greatly simplified, and simulation results shown the correctness of the simplified results. In addition, the detection areas of ground-based radar network can be easily computed with the

  17. Geospace Science from Ground-based Magnetometer Arrays: Advances in Sensors, Data Collection, and Data Integration

    NASA Astrophysics Data System (ADS)

    Mann, Ian; Chi, Peter

    2016-07-01

    Networks of ground-based magnetometers now provide the basis for the diagnosis of magnetic disturbances associated with solar wind-magnetosphere-ionosphere coupling on a truly global scale. Advances in sensor and digitisation technologies offer increases in sensitivity in fluxgate, induction coil, and new micro-sensor technologies - including the promise of hybrid sensors. Similarly, advances in remote connectivity provide the capacity for truly real-time monitoring of global dynamics at cadences sufficient for monitoring and in many cases resolving system level spatio-temporal ambiguities especially in combination with conjugate satellite measurements. A wide variety of the plasmaphysical processes active in driving geospace dynamics can be monitored based on the response of the electrical current system, including those associated with changes in global convection, magnetospheric substorms and nightside tail flows, as well as due to solar wind changes in both dynamic pressure and in response to rotations of the direction of the IMF. Significantly, any changes to the dynamical system must be communicated by the propagation of long-period Alfven and/or compressional waves. These wave populations hence provide diagnostics for not only the energy transport by the wave fields themselves, but also provide a mechanism for diagnosing the structure of the background plasma medium through which the waves propagate. Ultra-low frequency (ULF) waves are especially significant in offering a monitor for mass density profiles, often invisible to particle detectors because of their very low energy, through the application of a variety of magneto-seismology and cross-phase techniques. Renewed scientific interest in the plasma waves associated with near-Earth substorm dynamics, including magnetosphere-ionosphere coupling at substorm onset and their relation to magnetotail flows, as well the importance of global scale ultra-low frequency waves for the energisation, transport

  18. Progress report of FY 1999 activities: The application of Kalman filtering to derive water vapor profiles from combined ground-based sensors: Raman lidar, microwave radiometers, GPS, and radiosondes

    SciTech Connect

    Edgeworth R. Westwater; Yong Han

    1999-09-10

    Previously, the proposers have delivered to ARM a documented algorithm, that is now applied operationally, and which derives water vapor profiles from combined remote sensor measurements of water vapor radiometers, cloud-base ceilometers, and radio acoustic sounding systems (RASS). With the expanded deployment of a Raman lidar at the CART Central Facility, high quality, high vertical-resolution, water vapor profiles will be provided during nighttime clear conditions, and during clear daytime conditions, to somewhat lower altitudes. The object of this effort is to use Kalman Filtering, previously applied to the combination of nighttime Raman lidar and microwave radiometer data, to derive high-quality water vapor profiles, during non-precipitating conditions, from data routinely available at the CART site. Input data to the algorithm would include: Raman lidar data, highly quality-controlled data of integrated moisture from microwave radiometers and GPS, RASS, and radiosondes. While analyzing data obtained during the Water Vapor Intensive Operating Period'97 at the SGP CART site in central Oklahoma, several questions arose about the calibration of the ARM microwave radiometers (MWR). A large portion of this years effort was a thorough analysis of the many factors that are important for the calibration of this instrument through the tip calibration method and the development of algorithms to correct this procedure. An open literature publication describing this analysis has been accepted.

  19. Ground-based and spacecraft-based data sets: examples of synergy from recent missions

    NASA Astrophysics Data System (ADS)

    Buratti, Bonnie; Hicks, Michael; Bauer, James

    2015-08-01

    Missions to small bodies have returned a wealth of observations at high spatial resolution and new wavelengths. Nevertheless, spacecraft data is often deficient in many ways, lacking in temporal coverage, specific viewing geometries, context, spectral range, and calibrations. Several recent examples illustrate how modest ground-based “support” measurements for missions to small bodies have substantially enhanced the results from these missions. Triton, Neptune’s giant moon, was observed by Voyager 2 in 1989: high resolution images showed a sublimating polar cap and explosive plumes of volatiles. This instant in time was placed into context by subsequent ground-based and HST observations of the moon that showed continued volatile transport. Similarly, decades of ground-based observations leading up to the New Horizons fast flyby of Pluto monitored long-term changes in frosts on the dwarf planet’s surface. Another example of synergistic measurements for small-body missions is that of complementary solar phase angle coverage. Space-based missions seldom have small phase angle measurements; similarly, ground-based measurements are often lacking at large solar phase angles (except of course for NEOs). This complementary phase angle coverage enables accurate photometric modeling, including determination of the bolometric Bond albedo, which is a key parameter for thermal modeling. Another key use of ground-based observations is to check and refine spacecraft calibrations, at least at wavelengths that are visible from Earth. In some cases, complete calibration sets are provided by Earth-based observing programs, such as that of ROLO (RObotic Lunar Observatory) for the Moon. Finally, context and the “big picture” in both time and space are provided by telescopic views of spacecraft targets before, during, and after mission durations or critical events.The astronomical community should continue to support, and participate in, teams that make synergistic

  20. Comparison of MODIS and VIIRS cloud properties with ARM ground-based observations over Finland

    NASA Astrophysics Data System (ADS)

    Sporre, Moa K.; O'Connor, Ewan J.; Håkansson, Nina; Thoss, Anke; Swietlicki, Erik; Petäjä, Tuukka

    2016-07-01

    Cloud retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments aboard the satellites Terra and Aqua and the Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard the Suomi-NPP satellite are evaluated using a combination of ground-based instruments providing vertical profiles of clouds. The ground-based measurements are obtained from the Atmospheric Radiation Measurement (ARM) programme mobile facility, which was deployed in Hyytiälä, Finland, between February and September 2014 for the Biogenic Aerosols - Effects on Clouds and Climate (BAECC) campaign. The satellite cloud parameters cloud top height (CTH) and liquid water path (LWP) are compared with ground-based CTH obtained from a cloud mask created using lidar and radar data and LWP acquired from a multi-channel microwave radiometer. Clouds from all altitudes in the atmosphere are investigated. The clouds are diagnosed as single or multiple layer using the ground-based cloud mask. For single-layer clouds, satellites overestimated CTH by 326 m (14 %) on average. When including multilayer clouds, satellites underestimated CTH by on average 169 m (5.8 %). MODIS collection 6 overestimated LWP by on average 13 g m-2 (11 %). Interestingly, LWP for MODIS collection 5.1 is slightly overestimated by Aqua (4.56 %) but is underestimated by Terra (14.3 %). This underestimation may be attributed to a known issue with a drift in the reflectance bands of the MODIS instrument on Terra. This evaluation indicates that the satellite cloud parameters selected show reasonable agreement with their ground-based counterparts over Finland, with minimal influence from the large solar zenith angle experienced by the satellites in this high-latitude location.

  1. GLAST and Ground-Based Gamma-Ray Astronomy

    NASA Technical Reports Server (NTRS)

    McEnery, Julie

    2008-01-01

    The launch of the Gamma-ray Large Area Space Telescope together with the advent of a new generation of ground-based gamma-ray detectors such as VERITAS, HESS, MAGIC and CANGAROO, will usher in a new era of high-energy gamma-ray astrophysics. GLAST and the ground based gamma-ray observatories will provide highly complementary capabilities for spectral, temporal and spatial studies of high energy gamma-ray sources. Joint observations will cover a huge energy range, from 20 MeV to over 20 TeV. The LAT will survey the entire sky every three hours, allowing it both to perform uniform, long-term monitoring of variable sources and to detect flaring sources promptly. Both functions complement the high-sensitivity pointed observations provided by ground-based detectors. Finally, the large field of view of GLAST will allow a study of gamma-ray emission on large angular scales and identify interesting regions of the sky for deeper studies at higher energies. In this poster, we will discuss the science returns that might result from joint GLAST/ground-based gamma-ray observations and illustrate them with detailed source simulations.

  2. Preliminary design document: Ground based testbed for avionics systems

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The design and interface requirements for an avionics Ground Based Test bed (GBT) to support Heavy Lift Cargo Vehicles (HLCV) is presented. It also contains data on the vehicle subsystem configurations that are to be supported during their early, pre-PDR developmental phases. Several emerging technologies are also identified for support. A Preliminary Specification Tree is also presented.

  3. Cloud optical thickness retrievals from ground-based pyranometer measurements

    NASA Astrophysics Data System (ADS)

    Qiu, Jinhuan

    2006-11-01

    A method is developed to retrieve total cloud optical thickness (COT) from global solar radiation (GSR) detected by ground-based pyranometer, and approaches to input aerosol/molecular/gas parameters for COT retrievals are presented. On the basis of numerical simulations and comparative tests, main error factors of COT retrievals are analyzed, which include radiation data error, cloud inhomogeneity, uncertainties of aerosol optical parameters, and surface albedo. The retrieved COT error, caused by a -5% or 5% systematic error of the GSR measurement, is within ±0.6 and ±5.0 for COT ranges of 0-5.0 and 5-100, respectively. The AOT, the aerosol single scatter albedo (SSA), and the surface albedo are three significant parameters affecting COT retrieval accuracy. The mean SSA in the pyranometer spectral response range and the broadband surface albedo are suitably used in the retrievals. If uncertainties of AOT, SSA, and surface albedo are within ±0.1, ±0.05, and ±0.05, respectively, the retrieval accuracy is accepted for most applications. Furthermore, COTs (τPyr) from pyranometer data at two meteorological observatories are compared with COTs (τISCCP) from ISCCP and COTs (τMODIS) from MODIS. The relative standard deviations between monthly mean τPyr and τMODIS, or τPyr and τISCCP, are all less than 45.4% for both sites. The agreement among the yearly mean τPyr,τMODIS, and τISCCP is satisfactory. The absolute (relative) deviations between the yearly mean τPyr and τMODIS are within ±1.55 (8%) for both sites, and the deviations between the τPyr and τISCCP are within ±1.94 (25%). The yearly mean τPyr also agrees considerably well with τISCCP in the broken cloud case.

  4. A new research program for ground-based space radiobiology in Europe

    NASA Astrophysics Data System (ADS)

    Durante, M.; Kraft, G.; O'Neill, P.; Reitz, G.; Sabatier, L.; Schneider, U.

    Space radiation has been long acknowledged as a potential showstopper for long duration manned interplanetary missions Our knowledge of biological effects of cosmic radiation in deep space is almost exclusively derived from ground-based accelerator experiments with heavy ions in animal or in vitro models In an effort to gain more information on space radiation risk and to develop countermeasures NASA started several years ago a Space Radiation Health Program which is currently supporting biological experiments performed at the Brookhaven National Laboratory Upton NY Accelerator-based radiobiology research in the field of space radiation research is also under way in Russia and Japan The European Space Agency ESA has recently established an ambitious exploration program AURORA and within this program it has been decided to start a space radiation research program Europe has a wide tradition in radiobiology research at accelerators generally focussing on charged-particle cancer therapy This expertise can be adapted to address the issue of space radiation risk To support research in this field in Europe ESA issued in 2005 a call for tender for a preliminary study of investigations on biological effects of space radiation IBER This study will prepare future ESA supported-activities in space radiation research by selecting the best European accelerator facilities to be targeted for cooperation and by drafting a roadmap for future research activities The roadmap will include a prioritisation of research topics and a detailed proposal

  5. Ground-based microwave radar and optical lidar signatures of volcanic ash plumes: models, observations and retrievals

    NASA Astrophysics Data System (ADS)

    Mereu, Luigi; Marzano, Frank; Mori, Saverio; Montopoli, Mario; Cimini, Domenico; Martucci, Giovanni

    2013-04-01

    The detection and quantitative retrieval of volcanic ash clouds is of significant interest due to its environmental, climatic and socio-economic effects. Real-time monitoring of such phenomena is crucial, also for the initialization of dispersion models. Satellite visible-infrared radiometric observations from geostationary platforms are usually exploited for long-range trajectory tracking and for measuring low level eruptions. Their imagery is available every 15-30 minutes and suffers from a relatively poor spatial resolution. Moreover, the field-of-view of geostationary radiometric measurements may be blocked by water and ice clouds at higher levels and their overall utility is reduced at night. Ground-based microwave radars may represent an important tool to detect and, to a certain extent, mitigate the hazard from the ash clouds. Ground-based weather radar systems can provide data for determining the ash volume, total mass and height of eruption clouds. Methodological studies have recently investigated the possibility of using ground-based single-polarization and dual-polarization radar system for the remote sensing of volcanic ash cloud. A microphysical characterization of volcanic ash was carried out in terms of dielectric properties, size distribution and terminal fall speed, assuming spherically-shaped particles. A prototype of volcanic ash radar retrieval (VARR) algorithm for single-polarization systems was proposed and applied to S-band and C-band weather radar data. The sensitivity of the ground-based radar measurements decreases as the ash cloud is farther so that for distances greater than about 50 kilometers fine ash might be not detected anymore by microwave radars. In this respect, radar observations can be complementary to satellite, lidar and aircraft observations. Active remote sensing retrieval from ground, in terms of detection, estimation and sensitivity, of volcanic ash plumes is not only dependent on the sensor specifications, but also on

  6. Thunderstorms and ground-based radio noise as observed by radio astronomy Explorer 1

    NASA Technical Reports Server (NTRS)

    Caruso, J. A.; Herman, J. R.

    1973-01-01

    Radio Astronomy Explorer (RAE) data were analyzed to determine the frequency dependence of HF terrestrial radio noise power. RAE observations of individual thunderstorms, mid-ocean areas, and specific geographic regions for which concommitant ground based measurements are available indicate that noise power is a monotonically decreasing function of frequency which conforms to expectations over the geographic locations and time periods investigated. In all cases investigated, active thunderstorm regions emit slightly higher power as contrasted to RAE observations of the region during meteorologically quiet periods. Noise levels are some 15 db higher than predicted values over mid-ocean, while in locations where ground based measurements are available a maximum deviation of 5 db occurs. Worldwide contour mapping of the noise power at 6000 km for five individual months and four observing frequencies, examples of which are given, indicate high noise levels over continental land masses with corresponding lower levels over ocean regions.

  7. Ground-based grasslands data to support remote sensing and ecosystem modeling of terrestrial primary production

    NASA Technical Reports Server (NTRS)

    Olson, R. J.; Scurlock, J. M. O.; Turner, R. S.; Jennings, S. V.

    1995-01-01

    Estimating terrestrial net primary production (NPP) using remote-sensing tools and ecosystem models requires adequate ground-based measurements for calibration, parameterization, and validation. These data needs were strongly endorsed at a recent meeting of ecosystem modelers organized by the International Geosphere-Biosphere Program's (IGBP's) Data and Information System (DIS) and its Global Analysis, Interpretation, and Modelling (GAIM) Task Force. To meet these needs, a multinational, multiagency project is being coordinated by the IGBP DIS to compile existing NPP data from field sites and to regionalize NPP point estimates to various-sized grid cells. Progress at Oak Ridge National Laboratory (ORNL) on compiling NPP data for grasslands as part of the IGBP DIS data initiative is described. Site data and associated documentation from diverse field studies are being acquired for selected grasslands and are being reviewed for completeness, consistency, and adequacy of documentation, including a description of sampling methods. Data are being compiled in a database with spatial, temporal, and thematic characteristics relevant to remote sensing and global modeling. NPP data are available from the ORNL Distributed Active Archive Center (DAAC) for biogeochemical dynamics. The ORNL DAAC is part of the Earth Observing System Data and Information System, of the US National Aeronautics and Space Administration.

  8. Ground-based grasslands data to support remote sensing and ecosystem modeling of terrestrial primary production

    SciTech Connect

    Olson, R.J.; Turner, R.S.; Scurlock, J.M.O.; Jennings, S.V.

    1995-12-31

    Estimating terrestrial net primary production (NPP) using remote- sensing tools and ecosystem models requires adequate ground-based measurements for calibration, parameterization, and validation. These data needs were strongly endorsed at a recent meeting of ecosystem modelers organized by the International Geosphere-Biosphere Programme`s (IGBP`s) Data and Information System (DIS) and its Global Analysis, Interpretation, and Modelling (GAIM) Task Force. To meet these needs, a multinational, multiagency project is being coordinated by the IGBP DIS to compile existing NPP data from field sites and to regionalize NPP point estimates to various-sized grid cells. Progress at Oak Ridge National Laboratory (ORNL) on compiling NPP data for grasslands as part of the IGBP DIS data initiative is described. Site data and associated documentation from diverse field studies are being acquired for selected grasslands and are being reviewed for completeness, consistency, and adequacy of documentation, including a description of sampling methods. Data are being compiled in a database with spatial, temporal, and thematic characteristics relevant to remote sensing and global modeling. NPP data are available from the ORNL Distributed Active Archive Center (DAAC) for biogeochemical dynamics. The ORNL DAAC is part of the Earth Observing System Data and Information System, of the US National Aeronautics and Space Administration.

  9. Perspectives of astronomy in Kazakhstan: from new ground-based telescopes to space ones

    NASA Astrophysics Data System (ADS)

    Omarov, Ch. T.; Zhantayev, Zh. Sh.

    2012-09-01

    Astronomical observations in Kazakhstan are carried out for over 60 years. The advantage of the geographical location makes it possible to set and conduct programs of stationary ground-based observations, that from the most observatories of other countries are difficult or impossible. However outdated technical condition of scientific equipment, which include ground-based optical telescopes, poses a direct problem to the development of astronomy in Kazakhstan. In addition, observational data in the other spectral bands from space telescopes are needed. Therefore, in order to create a modern experimental astrophysical base today in Kazakhstan two projects are being put forward in the frame of national space program: 1) a new optical telescope with a primary mirror 3.6 meters (completed in 2016), and 2) participation in the international space project "World Space Observatory -Ultraviolet" that to be launched in 2014.

  10. Combined Characterisation of GOME and TOMS Total Ozone Using Ground-Based Observations from the NDSC

    NASA Technical Reports Server (NTRS)

    Lambert, J.-C.; VanRoozendael, M.; Simon, P. C.; Pommereau, J.-P.; Goutail, F.; Andersen, S. B.; Arlander, D. W.; BuiVan, N. A.; Claude, H.; deLaNoee, J.; DeMaziere, M.; Dorokhov, V.; Eriksen, P.; Gleason, J. F.; Tornkvist, K. Karlsen; Hoiskar, B. A. Kastad; Kyroe, E.; Leveau, J.; Merienne, M.-F.; Milinevsky, G.

    1998-01-01

    Several years of total ozone measured from space by the ERS-2 GOME, the Earth Probe Total Ozone Mapping Spectrometer (TOMS), and the ADEOS TOMS, are compared with high-quality ground-based observations associated with the Network for the Detection of Stratospheric Change (NDSC), over an extended latitude range and a variety of geophysical conditions. The comparisons with each spaceborne sensor are combined altogether for investigating their respective solar zenith angle (SZA) dependence, dispersion, and difference of sensitivity. The space- and ground-based data are found to agree within a few percent on average. However, the analysis highlights for both Global Ozone Monitoring Experiment (GOME) and TOMS several sources of discrepancies, including a dependence on the SZA at high latitudes and internal inconsistencies.

  11. The Validation of Ground Based Ozone Measurements over Korea.

    NASA Astrophysics Data System (ADS)

    Baek, K. H.; Kim, J. H.; Herman, J. R.; Haffner, D. P.; Kim, J.

    2015-12-01

    The Validation of Ground Based Ozone Measurements over KoreaKorea will launch GEMS instrument in 2018 onboard the Geostationary Korea Multi-Purpose Satellite to monitor tropospheric gas concentrations in both high temporal and spatial resolution. In order to utilize information from satellite, it is crucial to carry out validation of satellite data with respect to ground-based measurements because satellite retrievals suffer from large error. The purpose of this study is to examine the performance of total ozone measurements from Pandora, Brewer, and Dobson which will be used for validation of GEMS ozone product. Because single version of the satellite retrieval algorithm is used to process the entire data set for a given satellite instrument and satellite instrument characteristics are typically changing slowly, it is assumed that sudden jumps or large drifts in ground-satellite total ozone measurements difference for individual sites are commonly related to problems with ground-based measurements. Thereby, satellite measurements can be used to estimate the performance of the ground-based measurement network as well as to identify potential problems residing in individual station. As a reference of satellite ozone measurements, we have selected ozone data derived from OMI-TOMS V8.5 algorithm because it is a very robust algorithm that has well studied about various error sources such as the effects of aerosols and clouds, variation in shape of ozone profiles with season, latitude, and total ozone. For the future validation of GEMS measurements, Korea has planned to use Pandora measurement that has been started operating since 2012. However, Pandora measurements reported to have unusual high total column ozone in the presence of clouds from the comparison of Pandora with OMI total ozone during DISCOVERY-AQ campaign. In this study, we will analyze the Pandora measurements associated with cloud and introduce the statistical technique, Kalman Filter, to correct the

  12. Ground-Based Calibration Of A Microwave Landing System

    NASA Technical Reports Server (NTRS)

    Kiriazes, John J.; Scott, Marshall M., Jr.; Willis, Alfred D.; Erdogan, Temel; Reyes, Rolando

    1996-01-01

    System of microwave instrumentation and data-processing equipment developed to enable ground-based calibration of microwave scanning-beam landing system (MSBLS) at distances of about 500 to 1,000 ft from MSBLS transmitting antenna. Ensures accuracy of MSBLS near touchdown point, without having to resort to expense and complex logistics of aircraft-based testing. Modified versions prove useful in calibrating aircraft instrument landing systems.

  13. Postural Responses Following Space Flight and Ground Based Analogs

    NASA Technical Reports Server (NTRS)

    Kofman, Igor S.; Reschke, Millard F.; Cerisano, Jody M.; Fisher, Elizabeth A.; Tomilovskaya, Elena V.; Kozlovskaya, Inessa B.; Bloomberg, Jacob B.

    2013-01-01

    With the transition from the Shuttle program to the International Space Station (ISS), the opportunity to fly sensorimotor experiments in a weightless environment has become increasingly more difficult to obtain. As a result, more investigations have turned to ground-based analogs as a way of evaluating an experiment's viability. The two primary analogs available to most investigators are 6deg head down bed rest (HDBR) and dry immersion (DI). For the time being, HDBR investigations have been associated with studies conducted in the United States while the Russians and several other European Union states have concentrated their efforts on using DI as the space flight analog of choice. While either model may be viable for cardiovascular, bone and other system changes, vestibular and sensorimotor investigators have retained serious reservations of either analog's potential to serve as a replacement for a true weightless environment. These reservations have merit, but it is worthwhile to consider that not all changes associated with sensorimotor function during space flight are the result of top-down modifications, but may also be due to the lack, or change, of appropriate support surfaces applying force to the bottom of the feet. To this end we have compared quiet stance postural responses between short duration Space Shuttle flights, long duration ISS flights and HDBR of varying duration. Using these three platforms, representing different modifications of support we investigated postural ataxia using a quiet stance model. Quiet stance was obtained by asking the subjects to stand upright on a force plate, eyes open, arms at the side of the body for three min. From the force plate we obtained average sway velocity in two axes as well as length of line (stabilogram). These parameters were then related to EMG activity recorded from the medial gastrocnemius and lateral tibialis. It is significant to note that postural ataxia measured as quiet stance shows analogous

  14. Ground-based lidar for atmospheric boundary layer ozone measurements.

    PubMed

    Kuang, Shi; Newchurch, Michael J; Burris, John; Liu, Xiong

    2013-05-20

    Ground-based lidars are suitable for long-term ozone monitoring as a complement to satellite and ozonesonde measurements. However, current ground-based lidars are unable to consistently measure ozone below 500 m above ground level (AGL) due to both engineering issues and high retrieval sensitivity to various measurement errors. In this paper, we present our instrument design, retrieval techniques, and preliminary results that focus on the high-temporal profiling of ozone within the atmospheric boundary layer (ABL) achieved by the addition of an inexpensive and compact mini-receiver to the previous system. For the first time, to the best of our knowledge, the lowest, consistently achievable observation height has been extended down to 125 m AGL for a ground-based ozone lidar system. Both the analysis and preliminary measurements demonstrate that this lidar measures ozone with a precision generally better than ±10% at a temporal resolution of 10 min and a vertical resolution from 150 m at the bottom of the ABL to 550 m at the top. A measurement example from summertime shows that inhomogeneous ozone aloft was affected by both surface emissions and the evolution of ABL structures.

  15. Ground-Based Lidar for Atmospheric Boundary Layer Ozone Measurements

    NASA Technical Reports Server (NTRS)

    Kuang, Shi; Newchurch, Michael J.; Burris, John; Liu, Xiong

    2013-01-01

    Ground-based lidars are suitable for long-term ozone monitoring as a complement to satellite and ozonesonde measurements. However, current ground-based lidars are unable to consistently measure ozone below 500 m above ground level (AGL) due to both engineering issues and high retrieval sensitivity to various measurement errors. In this paper, we present our instrument design, retrieval techniques, and preliminary results that focus on the high-temporal profiling of ozone within the atmospheric boundary layer (ABL) achieved by the addition of an inexpensive and compact mini-receiver to the previous system. For the first time, to the best of our knowledge, the lowest, consistently achievable observation height has been extended down to 125 m AGL for a ground-based ozone lidar system. Both the analysis and preliminary measurements demonstrate that this lidar measures ozone with a precision generally better than 10% at a temporal resolution of 10 min and a vertical resolution from 150 m at the bottom of the ABL to 550 m at the top. A measurement example from summertime shows that inhomogeneous ozone aloft was affected by both surface emissions and the evolution of ABL structures.

  16. Specifying the Earth's Plasmasphere With Data Assimilation of Ground-Based Field-Line Resonance Measurements

    NASA Astrophysics Data System (ADS)

    Jorgensen, A. M.; Rivera, S.; McCarthy, N.; Ober, D. M.; Zesta, E.; Chi, P. J.; Moldwin, M.

    2009-12-01

    The plasmasphere is an important medium for propagation of the waves which contribute to the decay and acceleration of energetic particles in the radiation belts and ring current. Accurate knowledge of the plasmasphere evolution is thus an important element for accurately predicting the evolution of the energetic particle populations. A variety of routine measurements provide information about the plasmasphere, including ground-based and space-based magnetic field measurements, space based in-situ plasma density measurements, whistler wave measurements, TEC measurements from GPS receivers, and in some cases global EUV images. Combining these measurements with a physics-based model through a data assimilation scheme should, in principle, allow a better specification of the plasmasphere. Other information which can be used include information about the global magnetic and electric fields from a combination of measurements and models. In this paper we will discuss modeling the plasmasphere using ground-based field-line resonance measurements. The advantages of ground-based measurements over space-based measurements are the longevity of the magnetometer arrays, the potentially greater simultaneous coverage in local time and L-shell (as opposed to single-point satellite measurements), and the lower cost of maintaining the networks. In this paper we will explore using a network of ground-based magnetometers to constrain the evolution of the plasmasphere through a data assimilation scheme. We will use the Ober et al. [1997] plasmasphere model, a particle filter data assimilation scheme, and simulated field-line resonance measurements as well as measurements from the McMAC, MEASURE, SAMBA, and CARISMA, magnetometer arrays.

  17. Processing electronic photos of Mercury produced by ground based observation

    NASA Astrophysics Data System (ADS)

    Ksanfomality, Leonid

    New images of Mercury have been obtained by processing of ground based observations that were carried out using the short exposure technique. The disk of the planet extendeds usually from 6 to 7 arc seconds, with the linear size of the image in a focal plane of the telescope about 0.3-0.5 mm on the average. Processing initial millisecond electronic photos of the planet is very labour-consuming. Some features of processing of initial millisecond electronic photos by methods of correlation stacking were considered in (Ksanfomality et al., 2005; Ksanfomality and Sprague, 2007). The method uses manual selection of good photos including a so-called pilot- file, the search for which usually must be done manually. The pilot-file is the most successful one, in opinion of the operator. It defines the future result of the stacking. To change pilot-files increases the labor of processing many times. Programs of processing analyze the contents of a sample, find in it any details, and search for recurrence of these almost imperceptible details in thousand of other stacking electronic pictures. If, proceeding from experience, the form and position of a pilot-file still can be estimated, the estimation of a reality of barely distinct details in it is somewhere in between the imaging and imagination. In 2006-07 some programs of automatic processing have been created. Unfortunately, the efficiency of all automatic programs is not as good as manual selection. Together with the selection, some other known methods are used. The point spread function (PSF) is described by a known mathematical function which in its central part decreases smoothly from the center. Usually the width of this function is accepted at a level 0.7 or 0.5 of the maxima. If many thousands of initial electronic pictures are acquired, it is possible during their processing to take advantage of known statistics of random variables and to choose the width of the function at a level, say, 0.9 maxima. Then the

  18. Development of a Portable, Ground-Based Ozone Lidar Instrument for Tropospheric Ozone Research and Educational Training

    NASA Technical Reports Server (NTRS)

    Chyba, Thomas; Zenker, Thomas

    1998-01-01

    The objective of this project is to develop a portable, eye-safe, ground-based ozone lidar instrument specialized for ozone differential absorption lidar (DIAL) measurements in the troposphere. This prototype instrument is intended to operate at remote field sites and to serve as the basic unit for monitoring projects requiring multi-instrument networks, such as that discussed in the science plan for the Global Tropospheric Ozone Project (GTOP). This instrument will be based at HU for student training in lidar technology as well as atmospheric ozone data analysis and interpretation. It will be also available for off-site measurement campaigns and will serve as a test bed for further instrument development. Later development beyond this grant to extend the scientific usefulness of the instrument may include incorporation of an aerosol channel and upgrading the laser to make stratospheric ozone measurements. Undergraduate and graduate students have been and will be active participants in this research effort.

  19. Improvements to the FATOLA computer program including added actively controlled landing gear subroutines

    NASA Technical Reports Server (NTRS)

    Mall, G. H.

    1983-01-01

    Modifications to a multi-degree-of-freedom flexible aircraft take-off and landing analysis (FATOLA) computer program, including a provision for actively controlled landing gears to expand the programs simulation capabilities, are presented. Supplemental instructions for preparation of data and for use of the modified program are included.

  20. Precise ground-based solar photometry and variations of total irradiance

    NASA Technical Reports Server (NTRS)

    Chapman, G. A.; Herzog, A. D.; Lawrence, J. K.; Walton, S. R.; Hudson, H. S.; Fisher, B. M.

    1992-01-01

    Several empirical models of sunspot and facular irradiance effects were tested by assessing the degree of correlation between variations in the total solar irradiance, as measured by the active cavity radiometer irradiance monitor on the SMM and the measures of magnetic activity on the solar disk. This was done by analyzing images made during 21 days between June 20 and July 14, 1988. The paper also describes the instruments and the methods used to gather the ground-based photometric images, as well as the analysis procedure.

  1. Connecting ground-based in-situ observations, ground-based remote sensing and satellite data within the Pan Eurasian Experiment (PEEX) program

    NASA Astrophysics Data System (ADS)

    Petäjä, Tuukka; de Leeuw, Gerrit; Lappalainen, Hanna K.; Moisseev, Dmitri; O'Connor, Ewan; Bondur, Valery; Kasimov, Nikolai; Kotlyakov, Vladimir; Guo, Huadong; Zhang, Jiahua; Matvienko, Gennadii; Kerminen, Veli-Matti; Baklanov, Alexander; Zilitinkevich, Sergej; Kulmala, Markku

    2014-10-01

    Human activities put an increasing stress on the Earth' environment and push the safe and sustainable boundaries of the vulnerable eco-system. It is of utmost importance to gauge with a comprehensive research program the current status of the environment, particularly in the most vulnerable locations. The Pan-Eurasian Experiment (PEEX) is a new multidisciplinary research program aiming at resolving the major uncertainties in the Earth system science and global sustainability questions in the Arctic and boreal Pan-Eurasian regions. The PEEX program aims to (i) understand the Earth system and the influence of environmental and societal changes in both pristine and industrialized Pan-Eurasian environments, (ii) establish and sustain long-term, continuous and comprehensive ground-based airborne and seaborne research infrastructures, and utilize satellite data and multi-scale model frameworks filling the gaps of the insitu observational network, (iii) contribute to regional climate scenarios in the northern Pan-Eurasia and determine the relevant factors and interactions influencing human and societal wellbeing (iv) promote the dissemination of PEEX scientific results and strategies in scientific and stake-holder communities and policy making, (v) educate the next generation of multidisciplinary global change experts and scientists, and (vi) increase the public awareness of climate change impacts in the Pan- Eurasian region. In this contribution, we underline general features of the satellite observations relevant to the PEEX research program and how satellite observations connect to the ground-based observations.

  2. Space- and Ground-Based Observations of Exceptionally Young Asteroids

    NASA Astrophysics Data System (ADS)

    Tamblyn, P. M.; Merline, W. J.; Chapman, C. R.; Nesvorný, D.; Durda, D. D.

    2004-12-01

    We provide an overview and progress report on a suite of observations of very young asteroids. Three asteroid groups were previously identified through dynamical back integration as having arisen from very recent (<10 Myr) asteroid collisions (Nesvorný et al. 2002, Nature 417, 720; 2003 ApJ 591, 486). Hence these asteroid families provide an opportunity to probe the properties of the fragments of asteroid collisions before their characteristics have been masked by the aging and dynamical effects that dominate the observable properties of older asteroids. With a variety of observational programs, we aim to measure characteristics critical for comparison with hydrodynamical models of asteroid collisions. First, with a large Hubble Snapshot survey, we are testing if binaries are more prevalent among the young asteroids. This might be expected because ejection of mutually bound pairs is one mechanism for binary formation. Although our observed samples are small, we have discovered two new binaries among our control sample of old asteroids and none among the young asteroids sampled. We are extending the sample with ground-based Adaptive Optics at VLT, Gemini-N, Keck, and IRTF. In another ground-based experiment, we are measuring the lightcurve amplitudes and spin periods of these young asteroids for eventual comparison with simulations of asteroid breakup (e.g. Durda et al. 2004 Icarus 170, 243). Finally, with a Spitzer program, we are measuring the sizes and albedos of some of these young asteroids. This will immediately test if albedo is correlated with size or age, and provide the calibration for a ground-based determination of the size distribution. Together with the spin and shape information from lightcurves, these data will also further constrain the measurement of the Yarkovsky effect on main belt asteroids recently presented by Nesvorný & Bottke 2004 (Icarus, 170, 324).

  3. Inter-Comparison of Lightning Trends from Ground-Based Networks During Severe Weather: Applications Toward GLM

    NASA Technical Reports Server (NTRS)

    Carey, Lawrence D.; Schultz, Chris J.; Petersen, Walter A.; Rudlosky, Scott D.; Bateman, Monte; Cecil, Daniel J.; Blakeslee, Richard J.; Goodman, Steven J.

    2011-01-01

    The planned GOES-R Geostationary Lightning Mapper (GLM) will provide total lightning data on the location and intensity of thunderstorms over a hemispheric spatial domain. Ongoing GOES-R research activities are demonstrating the utility of total flash rate trends for enhancing forecasting skill of severe storms. To date, GLM total lightning proxy trends have been well served by ground-based VHF systems such as the Northern Alabama Lightning Mapping Array (NALMA). The NALMA (and other similar networks in Washington DC and Oklahoma) provide high detection efficiency (> 90%) and location accuracy (< 1 km) observations of total lightning within about 150 km from network center. To expand GLM proxy applications for high impact convective weather (e.g., severe, aviation hazards), it is desirable to investigate the utility of additional sources of continuous lightning that can serve as suitable GLM proxy over large spatial scales (order 100 s to 1000 km or more), including typically data denied regions such as the oceans. Potential sources of GLM proxy include ground-based long-range (regional or global) VLF/LF lightning networks such as the relatively new Vaisala Global Lightning Dataset (GLD360) and Weatherbug Total Lightning Network (WTLN). Before using these data in GLM research applications, it is necessary to compare them with LMAs and well-quantified cloud-to-ground (CG) lightning networks, such as Vaisala s National Lightning Detection Network (NLDN), for assessment of total and CG lightning location accuracy, detection efficiency and flash rate trends. Preliminary inter-comparisons from these lightning networks during selected severe weather events will be presented and their implications discussed.

  4. Kepler and Ground-Based Transits of the exo-Neptune HAT-P-11b

    NASA Technical Reports Server (NTRS)

    Deming, Drake; Sada, Pedro V.; Jackson, Brian; Peterson, Steven W.; Agol, Eric; Knutson, Heather A.; Jennings, Donald E.; Haase, Plynn; Bays, Kevin

    2011-01-01

    We analyze 26 archival Kepler transits of the exo-Neptune HAT-P-11b, supplemented by ground-based transits observed in the blue (B band) and near-IR (J band). Both the planet and host star are smaller than previously believed; our analysis yields Rp = 4.31 R xor 0.06 R xor and Rs = 0.683 R solar mass 0.009 R solar mass, both about 3 sigma smaller than the discovery values. Our ground-based transit data at wavelengths bracketing the Kepler bandpass serve to check the wavelength dependence of stellar limb darkening, and the J-band transit provides a precise and independent constraint on the transit duration. Both the limb darkening and transit duration from our ground-based data are consistent with the new Kepler values for the system parameters. Our smaller radius for the planet implies that its gaseous envelope can be less extensive than previously believed, being very similar to the H-He envelope of GJ 436b and Kepler-4b. HAT-P-11 is an active star, and signatures of star spot crossings are ubiquitous in the Kepler transit data. We develop and apply a methodology to correct the planetary radius for the presence of both crossed and uncrossed star spots. Star spot crossings are concentrated at phases 0.002 and +0.006. This is consistent with inferences from Rossiter-McLaughlin measurements that the planet transits nearly perpendicular to the stellar equator. We identify the dominant phases of star spot crossings with active latitudes on the star, and infer that the stellar rotational pole is inclined at about 12 deg 5 deg to the plane of the sky. We point out that precise transit measurements over long durations could in principle allow us to construct a stellar Butterfly diagram to probe the cyclic evolution of magnetic activity on this active K-dwarf star.

  5. Biosensors for EVA: Improved Instrumentation for Ground-based Studies

    NASA Technical Reports Server (NTRS)

    Soller, B.; Ellerby, G.; Zou, F.; Scott, P.; Jin, C.; Lee, S. M. C.; Coates, J.

    2010-01-01

    During lunar excursions in the EVA suit, real-time measurement of metabolic rate is required to manage consumables and guide activities to ensure safe return to the base. Metabolic rate, or oxygen consumption (VO2), is normally measured from pulmonary parameters but cannot be determined with standard techniques in the oxygen-rich environment of a spacesuit. Our group has developed novel near infrared spectroscopic (NIRS) methods to calculate muscle oxygen saturation (SmO 2), hematocrit, and pH, and we recently demonstrated that we can use our NIRS sensor to measure VO 2 on the leg during cycling. Our NSBRI project has 4 objectives: (1) increase the accuracy of the metabolic rate calculation through improved prediction of stroke volume; (2) investigate the relative contributions of calf and thigh oxygen consumption to metabolic rate calculation for walking and running; (3) demonstrate that the NIRS-based noninvasive metabolic rate methodology is sensitive enough to detect decrement in VO 2 in a space analog; and (4) improve instrumentation to allow testing within a spacesuit. Over the past year we have made progress on all four objectives, but the most significant progress was made in improving the instrumentation. The NIRS system currently in use at JSC is based on fiber optics technology. Optical fiber bundles are used to deliver light from a light source in the monitor to the patient, and light reflected back from the patient s muscle to the monitor for spectroscopic analysis. The fiber optic cables are large and fragile, and there is no way to get them in and out of the test spacesuit used for ground-based studies. With complimentary funding from the US Army, we undertook a complete redesign of the sensor and control electronics to build a novel system small enough to be used within the spacesuit and portable enough to be used by a combat medic. In the new system the filament lamp used in the fiber optic system was replaced with a novel broadband near infrared

  6. Precipitation signatures of ground-based VLF transmitters

    NASA Astrophysics Data System (ADS)

    Kulkarni, P.; Inan, U. S.; Bell, T. F.; Bortnik, J.

    2008-07-01

    Numerical raytracing with Landau damping is used to calculate >100 keV electron precipitation signatures induced by hypothetical VLF transmitters distributed broadly in geomagnetic latitude and operating at a wide range of frequencies. A one-half second pulse from each source is simulated and attenuation to the base of the magnetosphere for geomagnetic latitudes from 10° to 60° is calculated. Source location affects induced precipitation more strongly than operating frequency or radiated power. Sources located at 35° to 45° induce the most >100 keV precipitation for the 10 to 40 kHz waves typical of ground-based VLF sources, while locations below λ ≃ 15° or above λ ≃ 55° are least effective at precipitating energetic electrons. In all cases, induced precipitation increases as the operating frequency decreases, with 10 kHz waves from a source at λ ≃ 35° the most effective at precipitating >100 keV electrons. Precipitation signatures produced by five existing ground-based VLF transmitters are also simulated: the NAA, NLK, NAU, NPM, and NWC VLF transmitters. NWC induces the strongest >100 keV electron precipitation signature, followed by NPM, NAU, NAA, and NLK.

  7. Light pollution simulations for planar ground-based light sources.

    PubMed

    Kocifaj, Miroslav

    2008-02-20

    The light pollution model is employed to analyze spatial behavior of luminance at the night sky under cloudless and overcast conditions. Enhanced light excess is particularly identified at cloudy skies, because the clouds efficiently contribute to the downward luminous flux. It is evident that size of ground-based light sources can play an important role in the case of overcast sky conditions. Nevertheless, the realistically sized light sources are rarely embedded into light pollution modeling, and rather they are replaced by simple point sources. We discuss the discrepancies between sky luminance distributions when at first the planar light sources are considered and at second the point-source approximation is accepted. The found differences are noticeable if the size of the light source, distance to the observer, and altitude of a cloudy layer are comparable one to the other. Compared with point-source approximation, an inclusion of the size factor into modeling the light sources leads to partial elimination of the steep changes of sky luminance (typical for point sources of light). The narrow and sharp light pillars normally presented on the sky illuminated by point light sources can disappear or fuse together when two or more nearby light sources are considered with their real sizes. Sky elements situated close to the horizon will glow efficiently if luminous flux originates from two-dimensional ground-based entities (such as cities or villages).

  8. Statistical Studies of Ground-Based Optical Lightning Signatures

    NASA Astrophysics Data System (ADS)

    Hunt, C. R.; Nemzek, R. J.; Suszcynsky, D. M.

    2005-12-01

    Most extensive optical studies of lightning have been conducted from orbit, and the statistics of events collected from earth are relatively poorly documented. The time signatures of optical power measured in the presence of clouds are inevitably affected by scattering,which can distort the signatures by extending and delaying the amplitude profile in time. We have deployed two all-sky photodiode detectors, one in New Mexico and one in Oklahoma, which are gathering data alongside electric field change monitors as part of the LANL EDOTX Great Plains Array. Preliminary results show that the photodiode is sensitive to approximately 50% or more of RF events detected at ranges of up to 30 km, and still has some sensitivity at ranges in excess of 60 km (distances determined by the EDOTX field-change array). The shapes of events within this range were assessed, with focus on rise time, width, peak power, and their correlation to corresponding electric field signatures, and these are being compared with published on-orbit and ground-based data. Initial findings suggest a mean characteristic width (ratio of total detected optical energy to peak power) of 291 +/- 12 microseconds and a mean delay between the RF signal peak and optical peak of 121 +/- 17 microseconds. These values fall between prior ground-based measurements of direct return stroke emissions, and scattering-dominated on-orbit measurements. This work will promote better understanding of the correspondence between radio and optical measurements of lightning.

  9. Ground-based visual inspection for CTBT verification

    SciTech Connect

    Hawkins, W.; Wohletz, K.

    1997-11-01

    Ground-based visual inspection will play an essential role in On-Site Inspection (OSI) for Comprehensive Test Ban Treaty (CTBT) verification. Although seismic and remote sensing techniques are the best understood and most developed methods for detection of evasive testing of nuclear weapons, visual inspection will greatly augment the certainty and detail of understanding provided by these more traditional methods. Not only can ground-based visual inspection offer effective documentation in cases of suspected nuclear testing, but it also can provide accurate source location and testing media properties necessary for detailed analysis of seismic records. For testing in violation of the CTBT, an offending state may attempt to conceal the test, which most likely will be achieved by underground burial. While such concealment may not prevent seismic detection, evidence of test deployment, location, and yield can be disguised. In this light, if a suspicious event is detected by seismic or other remote methods, visual inspection of the event area is necessary to document any evidence that might support a claim of nuclear testing and provide data needed to further interpret seismic records and guide further investigations. However, the methods for visual inspection are not widely known nor appreciated, and experience is presently limited. Visual inspection can be achieved by simple, non-intrusive means, primarily geological in nature, and it is the purpose of this report to describe the considerations, procedures, and equipment required to field such an inspection. The inspections will be carried out by inspectors from members of the CTBT Organization.

  10. MODELING ATMOSPHERIC EMISSION FOR CMB GROUND-BASED OBSERVATIONS

    SciTech Connect

    Errard, J.; Borrill, J.; Ade, P. A. R.; Akiba, Y.; Chinone, Y.; Arnold, K.; Atlas, M.; Barron, D.; Elleflot, T.; Baccigalupi, C.; Fabbian, G.; Boettger, D.; Chapman, S.; Cukierman, A.; Delabrouille, J.; Ducout, A.; Feeney, S.; Feng, C.; and others

    2015-08-10

    Atmosphere is one of the most important noise sources for ground-based cosmic microwave background (CMB) experiments. By increasing optical loading on the detectors, it amplifies their effective noise, while its fluctuations introduce spatial and temporal correlations between detected signals. We present a physically motivated 3D-model of the atmosphere total intensity emission in the millimeter and sub-millimeter wavelengths. We derive a new analytical estimate for the correlation between detectors time-ordered data as a function of the instrument and survey design, as well as several atmospheric parameters such as wind, relative humidity, temperature and turbulence characteristics. Using an original numerical computation, we examine the effect of each physical parameter on the correlations in the time series of a given experiment. We then use a parametric-likelihood approach to validate the modeling and estimate atmosphere parameters from the polarbear-i project first season data set. We derive a new 1.0% upper limit on the linear polarization fraction of atmospheric emission. We also compare our results to previous studies and weather station measurements. The proposed model can be used for realistic simulations of future ground-based CMB observations.

  11. Airborne and Ground-Based Measurements Using a High-Performance Raman Lidar. Part 2; Ground Based

    NASA Technical Reports Server (NTRS)

    Whiteman, David N.; Cadirola, Martin; Venable, Demetrius; Connell, Rasheen; Rush, Kurt; Leblanc, Thierry; McDermid, Stuart

    2009-01-01

    The same RASL hardware as described in part I was installed in a ground-based mobile trailer and used in a water vapor lidar intercomparison campaign, hosted at Table Mountain, CA, under the auspices of the Network for the Detection of Atmospheric Composition Change (NDACC). The converted RASL hardware demonstrated high sensitivity to lower stratospheric water vapor indicating that profiling water vapor at those altitudes with sufficient accuracy to monitor climate change is possible. The measurements from Table Mountain also were used to explain the reason, and correct , for sub-optimal airborne aerosol extinction performance during the flight campaign.

  12. A Preliminary Assessment of Phase Separator Ground-Based and Reduced-Gravity Testing for ALS Systems

    NASA Technical Reports Server (NTRS)

    Hall, Nancy Rabel

    2006-01-01

    A viewgraph presentation of phase separator ground-based and reduced-gravity testing for Advanced Life Support (ALS) systems is shown. The topics include: 1) Multiphase Flow Technology Program; 2) Types of Separators; 3) MOBI Phase Separators; 4) Experiment set-up; and 5) Preliminary comparison/results.

  13. Population and Human Development: A Course Curriculum Including Lesson Plans, Activities, and Bibliography. Revised.

    ERIC Educational Resources Information Center

    Murphy, Elaine M.; Long, Alison T.

    This course outline suggests materials and learning activities on the interrelated causes and consequences of population growth and other population matters. The document describes 15 class sessions which integrate information for sociology, anthropology, psychology, biology, animal behavior, and education. Topics include the history of human…

  14. 76 FR 10385 - Agency Information Collection Activities: Various Contract Related Forms That Will be Included in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-24

    ... SECURITY Agency Information Collection Activities: Various Contract Related Forms That Will be Included in the Homeland Security Acquisition Regulation, DHS FORM 0700-01, DHS FORM 0700-02, DHS FORM 0700-03...: The Department of Homeland Security, Office of Chief Procurement Officer, Acquisition Policy...

  15. Comparison of Thermal Structure Results from Venus Express and Ground Based Observations since Vira

    NASA Astrophysics Data System (ADS)

    Limaye, Sanjay

    2016-07-01

    An international team was formed in 2013 through the International Space Studies Institute (Bern, Switzerland) to compare recent results of the Venus atmospheric thermal structure from spacecraft and ground based observations made since the Venus International Reference Atmosphere (VIRA) was developed (Kliore et al., 1985, Keating et al., 1985). Five experiments on European Space Agency's Venus Express orbiter mission have yielded results on the atmospheric structure during is operational life (April 2006 - November 2014). Three of these were from occultation methods: at near infrared wavelengths from solar occultations, (SOIR, 70 - 170 km), at ultraviolet wavelengths from stellar occultations (SPICAV, 90-140 km), and occultation of the VEx-Earth radio signal (VeRa, 40-90 km). In-situ drag measurements from three different techniques (accelerometry, torque, and radio tracking, 130 - 200 km) were also obtained using the spacecraft itself while passive infrared remote sensing was used by the VIRTIS experiment (70 - 120 km). The only new data in the -40-70 km altitude range are from radio occultation, as no new profiles of the deep atmosphere have been obtained since the VeGa 2 lander measurements in 1985 (not included in VIRA). Some selected ground based results available to the team were also considered by team in the inter comparisons. The temperature structure in the lower thermosphere from disk resolved ground based observations (except for one ground based investigation), is generally consistent with the Venus Express results. These experiments sampled at different periods, at different locations and at different local times and have different vertical and horizontal resolution and coverage. The data were therefore binned in latitude and local time bins and compared, ignoring temporal variations over the life time of the Venus Express mission and assumed north-south symmetry. Alternating warm and cooler layers are present in the 120-160 altitude range in results

  16. Exo-zodi detection capability of the Ground-Based European Nulling Interferometry Experiment (GENIE) instrument.

    PubMed

    Wallner, Oswald; Flatscher, Reinhold; Ergenzinger, Klaus

    2006-06-20

    The Ground-Based European Nulling Interferometry Experiment (GENIE) is intended as an Earth-based precursor for the European Darwin mission that will prepare the Darwin science program and demonstrate the required technology at system level. We propose a compact nulling interferometer design consisting of a two-telescope aperture configuration, an optional split-pupil add-on, and only four active control loops for counteracting environmentally induced disturbances. We show by simulation that the proposed instrument is able to detect, within a few minutes of observation time, exo-zodiacal dust clouds around Sunlike stars at 20 parsecs that are 20 times stronger than the local zodiacal dust cloud density.

  17. Test and training simulator for ground-based teleoperated in-orbit servicing

    NASA Technical Reports Server (NTRS)

    Schaefer, Bernd E.

    1989-01-01

    For the Post-IOC(In-Orbit Construction)-Phase of COLUMBUS it is intended to use robotic devices for the routine operations of ground-based teleoperated In-Orbit Servicing. A hardware simulator for verification of the relevant in-orbit operations technologies, the Servicing Test Facility, is necessary which mainly will support the Flight Control Center for the Manned Space-Laboratories for operational specific tasks like system simulation, training of teleoperators, parallel operation simultaneously to actual in-orbit activities and for the verification of the ground operations segment for telerobotics. The present status of definition for the facility functional and operational concept is described.

  18. Zero-Gravity Locomotion Simulators: New Ground-Based Analogs for Microgravity Exercise Simulation

    NASA Technical Reports Server (NTRS)

    Perusek, Gail P.; DeWitt, John K.; Cavanagh, Peter R.; Grodsinsky, Carlos M.; Gilkey, Kelly M.

    2007-01-01

    Maintaining health and fitness in crewmembers during space missions is essential for preserving performance for mission-critical tasks. NASA's Exercise Countermeasures Project (ECP) provides space exploration exercise hardware and monitoring requirements that lead to devices that are reliable, meet medical, vehicle, and habitat constraints, and use minimal vehicle and crew resources. ECP will also develop and validate efficient exercise prescriptions that minimize daily time needed for completion of exercise yet maximize performance for mission activities. In meeting these mission goals, NASA Glenn Research Center (Cleveland, OH, USA), in collaboration with the Cleveland Clinic (Cleveland, Ohio, USA), has developed a suite of zero-gravity locomotion simulators and associated technologies to address the need for ground-based test analog capability for simulating in-flight (microgravity) and surface (partial-gravity) exercise to advance the health and safety of astronaut crews and the next generation of space explorers. Various research areas can be explored. These include improving crew comfort during exercise, and understanding joint kinematics and muscle activation pattern differences relative to external loading mechanisms. In addition, exercise protocol and hardware optimization can be investigated, along with characterizing system dynamic response and the physiological demand associated with advanced exercise device concepts and performance of critical mission tasks for Exploration class missions. Three zero-gravity locomotion simulators are currently in use and the research focus for each will be presented. All of the devices are based on a supine subject suspension system, which simulates a reduced gravity environment by completely or partially offloading the weight of the exercising test subject s body. A platform for mounting treadmill is positioned perpendicularly to the test subject. The Cleveland Clinic Zero-g Locomotion Simulator (ZLS) utilizes a

  19. Ground-Based Gas-Liquid Flow Research in Microgravity Conditions: State of Knowledge

    NASA Technical Reports Server (NTRS)

    McQuillen, J.; Colin, C.; Fabre, J.

    1999-01-01

    During the last decade, ground-based microgravity facilities have been utilized in order to obtain predictions for spacecraft system designers and further the fundamental understanding of two-phase flow. Although flow regime, pressure drop and heat transfer coefficient data has been obtained for straight tubes and a limited number of fittings, measurements of the void fraction, film thickness, wall shear stress, local velocity and void information are also required in order to develop general mechanistic models that can be utilized to ascertain the effects of fluid properties, tube geometry and acceleration levels. A review of this research is presented and includes both empirical data and mechanistic models of the flow behavior.

  20. Performance of ground-based high-frequency receiving arrays with electrically-small ground planes

    NASA Astrophysics Data System (ADS)

    Weiner, M. M.

    1991-09-01

    Electrically-small ground planes degrade the performance of ground-based high-frequency receiving arrays because the arrays are more susceptible to earth multipath, ground losses, and external currents on element feed cables. Performance degradations include a reduction in element directive gain near the horizon, distortion of the element azimuthal pattern, an increase in the system internal noise factor, and increases in the array factor root-mean-squared (rms) phase error and beam-pointing errors. The advantage of electrically-small ground planes is their relatively low cost of construction and maintenance.

  1. Estimating forest LAI profiles and structural parameters using a ground-based laser called 'Echidna'.

    PubMed

    Jupp, David L B; Culvenor, D S; Lovell, J L; Newnham, G J; Strahler, A H; Woodcock, C E

    2009-02-01

    There are many techniques for measuring leaf area index (LAI) and forest canopy foliage profiles but their accuracy is questionable. This paper briefly reviews current methods of estimating forest LAI and presents a novel, ground-based laser system, Echidna that can make a wide range of measurements of forest structure, including LAI. Here, use of the system to provide field data and derived gap probabilities in the form of a 'hemispherical photograph with range' is demonstrated. The results show consistency and reproducibility and do not depend on special conditions for the natural light field. PMID:19203942

  2. Initial ground-based thermospheric wind measurements using Doppler asymmetric spatial heterodyne spectroscopy (DASH).

    PubMed

    Englert, Christoph R; Harlander, John M; Emmert, John T; Babcock, David D; Roesler, Frederick L

    2010-12-20

    We present the first thermospheric wind measurements using a Doppler Asymmetric Spatial Heterodyne (DASH) spectrometer and the oxygen red-line nightglow emission. The ground-based observations were made from Washington, DC and include simultaneous calibration measurements to track and correct instrument drifts. Even though the measurements were made under challenging thermal and light pollution conditions, they are of good quality with photon statistics uncertainties between about three and twenty-nine meters per second, depending on the nightglow intensity. The wind data are commensurate with a representative set of Millstone Hill Fabry-Perot wind measurements selected for similar geomagnetic and solar cycle conditions.

  3. Initial ground-based thermospheric wind measurements using Doppler asymmetric spatial heterodyne spectroscopy (DASH).

    PubMed

    Englert, Christoph R; Harlander, John M; Emmert, John T; Babcock, David D; Roesler, Frederick L

    2010-12-20

    We present the first thermospheric wind measurements using a Doppler Asymmetric Spatial Heterodyne (DASH) spectrometer and the oxygen red-line nightglow emission. The ground-based observations were made from Washington, DC and include simultaneous calibration measurements to track and correct instrument drifts. Even though the measurements were made under challenging thermal and light pollution conditions, they are of good quality with photon statistics uncertainties between about three and twenty-nine meters per second, depending on the nightglow intensity. The wind data are commensurate with a representative set of Millstone Hill Fabry-Perot wind measurements selected for similar geomagnetic and solar cycle conditions. PMID:21197018

  4. GROMOS-C, a novel ground based microwave radiometer for ozone measurement campaigns

    NASA Astrophysics Data System (ADS)

    Fernandez, S.; Murk, A.; Kämpfer, N.

    2015-03-01

    Stratospheric ozone is of major interest as it absorbs most of harmful UV radiation from the sun, allowing life on Earth. Ground based microwave remote sensing is the only method that allows to measure ozone profiles up to the mesopause, 24 h and under different weather conditions with high time resolution. In this paper a novel ground based microwave radiometer is presented. It is called GROMOS-C (GRound based Ozone MOnitoring System for Campaigns), and it has been designed to measure the vertical profile of ozone distribution in the middle atmosphere, by observing ozone emission spectra at a frequency of 110.836 GHz. The instrument is designed in a compact way which makes it transportable and suitable for outdoor use in campaigns, an advantageous feature that is lacking in present day ozone radiometers. It is operated through remote control. GROMOS-C is a total power radiometer which uses a preamplified heterodyne receiver, and a digital Fast Fourier Transform spectrometer for the spectral analysis. Among its main new features stands out the incorporation of different calibration loads, including a noise diode and a new type of blackbody target specifically designed for this instrument, based on Peltier elements. The calibration scheme does not depend on the use of liquid nitrogen, therefore GROMOS-C can be operated at remote places with no maintenance requirements. In addition the instrument can be switched in frequency to observe the CO line at 115 GHz. A description of the main characteristics of GROMOS-C is included in this paper, as well as the results of a first campaign at the High Altitude Research Station in Jungfraujoch (HFSJ), Switzerland. The validation is performed by comparison of the retrieved profiles against equivalent profiles from MLS satellite data, ECMWF model data, as well as our nearby NDACC ozone radiometer measuring at Bern.

  5. GROMOS-C, a novel ground-based microwave radiometer for ozone measurement campaigns

    NASA Astrophysics Data System (ADS)

    Fernandez, S.; Murk, A.; Kämpfer, N.

    2015-07-01

    Stratospheric ozone is of major interest as it absorbs most harmful UV radiation from the sun, allowing life on Earth. Ground-based microwave remote sensing is the only method that allows for the measurement of ozone profiles up to the mesopause, over 24 hours and under different weather conditions with high time resolution. In this paper a novel ground-based microwave radiometer is presented. It is called GROMOS-C (GRound based Ozone MOnitoring System for Campaigns), and it has been designed to measure the vertical profile of ozone distribution in the middle atmosphere by observing ozone emission spectra at a frequency of 110.836 GHz. The instrument is designed in a compact way which makes it transportable and suitable for outdoor use in campaigns, an advantageous feature that is lacking in present day ozone radiometers. It is operated through remote control. GROMOS-C is a total power radiometer which uses a pre-amplified heterodyne receiver, and a digital fast Fourier transform spectrometer for the spectral analysis. Among its main new features, the incorporation of different calibration loads stands out; this includes a noise diode and a new type of blackbody target specifically designed for this instrument, based on Peltier elements. The calibration scheme does not depend on the use of liquid nitrogen; therefore GROMOS-C can be operated at remote places with no maintenance requirements. In addition, the instrument can be switched in frequency to observe the CO line at 115 GHz. A description of the main characteristics of GROMOS-C is included in this paper, as well as the results of a first campaign at the High Altitude Research Station at Jungfraujoch (HFSJ), Switzerland. The validation is performed by comparison of the retrieved profiles against equivalent profiles from MLS (Microwave Limb Sounding) satellite data, ECMWF (European Centre for Medium-Range Weather Forecast) model data, as well as our nearby NDACC (Network for the Detection of Atmospheric

  6. Specifying the Earth's Plasmasphere With Data Assimilation of Ground-Based Field-Line Resonance Measurements

    NASA Astrophysics Data System (ADS)

    Jorgensen, Anders; McCarthy, Nicholas; Rivera, Samuell; Ober, Daniel; Zesta, Eftyhia; Chi, Peter; Moldwin, Mark; Ridley, Aaron

    The plasmasphere is an important medium for propagation of the waves which contribute to the decay and acceleration of energetic particles in the radiation belts and ring current. Accurate knowledge of the plasmasphere evolution is important for accurately predicting the evolution of the energetic particle populations. A variety of routine measurements provide information about the plasmasphere, including ground-based and space-based magnetic field-line resonance measurements, space based in-situ plasma density measurements, whistler wave measurements, TEC measurements from GPS receivers, and in some cases global EUV images. Combining these measurements with a physics-based model through a data assimilation scheme should, in principle, allow a better specification of the plasmasphere. Other information which can be used include information about the global magnetic and electric fields from a combination of measurements and models, for example AMIE. In this presentation we will discuss modeling the plasmasphere using these data. A particular advantage of ground-based measurements over space-based measurements are the longevity of the magnetometer and VLF stations, the potentially greater simultaneous coverage in local time and L-shell (as opposed to single-point satellite measurements), and the lower cost of maintaining the networks. In this paper we will explore using a network of ground-based magnetometers to constrain the evolution of the plas-masphere through a data assimilation scheme. We will use the Ober et al. [1997] plasmasphere model, a particle filter data assimilation scheme, and simulated or actual field-line resonance measurements from the McMAC, MEASURE, SAMBA, and CARISMA, magnetometer arrays.

  7. Ground-based column abundance measurements of atmospheric hydroxyl

    NASA Technical Reports Server (NTRS)

    Burnett, Clyde R.

    1988-01-01

    The preliminary results of ground-based OH column abundance measurements from Truk, Federated States of Micronesia, are contained. These are the first OH column measurements from the tropics, and constitute a signficcant contribution to the OH data base. Comparisons of tropical OH behavior with the extensive mid-latitude observations serve as a critical test of the current understanding of the HO (sub x) photochemistry and its relationship to the other major chemical families. The quasi-biennial oscillation (QBO) in tropical stratospheric winds exerts a major influence on the Hadley cell vertical transport. Related QBOs in total O3 and in stratospheric H2O were identified, but QBO effects on other stratospheric species are still unknown. The solar tide in the tropics produces a diurnal surface pressure variation of 2 to 3 mb; its effect on OH photochemistry in the stratosphere may be significant.

  8. Ground-based column abundance measurements of atmospheric hydroxyl

    NASA Astrophysics Data System (ADS)

    Burnett, Clyde R.

    1988-04-01

    The preliminary results of ground-based OH column abundance measurements from Truk, Federated States of Micronesia, are contained. These are the first OH column measurements from the tropics, and constitute a signficcant contribution to the OH data base. Comparisons of tropical OH behavior with the extensive mid-latitude observations serve as a critical test of the current understanding of the HO (sub x) photochemistry and its relationship to the other major chemical families. The quasi-biennial oscillation (QBO) in tropical stratospheric winds exerts a major influence on the Hadley cell vertical transport. Related QBOs in total O3 and in stratospheric H2O were identified, but QBO effects on other stratospheric species are still unknown. The solar tide in the tropics produces a diurnal surface pressure variation of 2 to 3 mb; its effect on OH photochemistry in the stratosphere may be significant.

  9. GBOT: ground based optical tracking of the Gaia satellite

    NASA Astrophysics Data System (ADS)

    Altmann, Martin; Bouquillon, Sebastien; Taris, Francois; Steele, Iain A.; Smart, Ricky L.; Andrei, Alexandre H.; Barache, Christophe; Carlucci, Teddy; Els, Sebastian G.

    2014-08-01

    Gaia, the 1 billion star, high precision, astrometric satellite will revolutionise our understanding in many areas of astronomy ranging from bodies in our Solar System to the formation and structure of our Galaxy. To fully achieve the ambitious goals of the mission, and to completely eliminate effects such as aberration, we must know the position and velocity vectors of the spacecraft as it orbits the Lagrange point to an accuracy greater than can be obtained by traditional radar techniques, leading to the decision to conduct astrometric observations of the Gaia satellite itself from the ground. Therefore the Ground Based Optical Tracking (GBOT) project was formed and a small worldwide network using 1-2 m telescopes established in order to obtain one measurement per day of a precision/accuracy of 20 mas. We will discuss all aspects of GBOT, setup, feasibility considerations, preliminary tests of observing methods, partner observatories, the pipeline/database (see also contribution by Bouquillon et al.1).

  10. Ground-Based Experiments on Vibrational Thermal Convection

    NASA Technical Reports Server (NTRS)

    Schatz, Michael F.; Rogers, Jeffrey L.

    1999-01-01

    Ground-based experiments on g-jitter effects in fluid flow provide insight that complements both theoretical studies and space-based experiments on this problem. We report preliminary results for experiments on Rayleigh-Benard convection subjected to time-dependent accelerations on a shaker table. For sinusoidal modulation, two qualitatively different pattern forming mechanisms come into play: geometry induced wavenumber selection (as in the standard "no-shake" Rayleigh-Benard problem) and dispersion induced wavenumber selection due to parametric instability (as in the Faraday surface-wave problem). We discuss preliminary results on the competition and co-existence of patterns due to these different instability mechanisms. We also discuss the implications of this work on the general question of pattern formation in the presence of noise.

  11. Unique cell culture systems for ground based research

    NASA Technical Reports Server (NTRS)

    Lewis, Marian L.

    1990-01-01

    The horizontally rotating fluid-filled, membrane oxygenated bioreactors developed at NASA Johnson for spacecraft applications provide a powerful tool for ground-based research. Three-dimensional aggregates formed by cells cultured on microcarrier beads are useful for study of cell-cell interactions and tissue development. By comparing electron micrographs of plant seedlings germinated during Shuttle flight 61-C and in an earth-based rotating bioreactor it is shown that some effects of microgravity are mimicked. Bioreactors used in the UAH Bioreactor Laboratory will make it possible to determine some of the effects of altered gravity at the cellular level. Bioreactors can be valuable for performing critical, preliminary-to-spaceflight experiments as well as medical investigations such as in vitro tumor cell growth and chemotherapeutic drug response; the enrichment of stem cells from bone marrow; and the effect of altered gravity on bone and muscle cell growth and function and immune response depression.

  12. Progress in the ULTRA 1-m ground-based telescope

    NASA Astrophysics Data System (ADS)

    Romeo, Robert C.; Martin, Robert N.; Twarog, Bruce; Anthony-Twarog, Barbara; Taghavi, Ray; Hale, Rick; Etzel, Paul; Fesen, Rob; Shawl, Steve

    2006-06-01

    We present the technical status of the Ultra Lightweight Telescope for Research in Astronomy (ULTRA) program. The program is a 3-year Major Research Instrumentation (MRI) program funded by NSF. The MRI is a collaborative effort involving Composite Mirror Applications, Inc. (CMA), University of Kansas, San Diego State University and Dartmouth College. Objectives are to demonstrate the feasibility of carbon fiber reinforced plastic (CFRP) composite mirror technology for ground-based optical telescopes. CMA is spearheading the development of surface replication techniques to produce the optics, fabricating the 1m glass mandrel, and constructing the optical tube assembly (OTA). Presented will be an overview and status of the 1-m mandrel fabrication, optics development, telescope design and CFRP telescope fabrication by CMA for the ULTRA Telescope.

  13. Laminar Premixed and Diffusion Flames (Ground-Based Study)

    NASA Technical Reports Server (NTRS)

    Dai, Z.; El-Leathy, A. M.; Lin, K.-C.; Sunderland, P. B.; Xu, F.; Faeth, G. M.; Urban, D. L. (Technical Monitor); Yuan, Z.-G. (Technical Monitor)

    2000-01-01

    Ground-based studies of soot processes in laminar flames proceeded in two phases, considering laminar premixed flames and laminar diffusion flames, in turn. The test arrangement for laminar premixed flames involved round flat flame burners directed vertically upward at atmospheric pressure. The test arrangement for laminar jet diffusion flames involved a round fuel port directed vertically upward with various hydrocarbon fuels burning at atmospheric pressure in air. In both cases, coflow was used to prevent flame oscillations and measurements were limited to the flame axes. The measurements were sufficient to resolve soot nucleation, growth and oxidation rates, as well as the properties of the environment needed to evaluate mechanisms of these processes. The experimental methods used were also designed to maintain capabilities for experimental methods used in corresponding space-based experiments. This section of the report will be limited to consideration of flame structure for both premixed and diffusion flames.

  14. Modelling atmospheric turbulence effects on ground-based telescope systems

    SciTech Connect

    Bradford, L.W.; Flatte, S.M.; Max, C.E.

    1993-09-30

    Questions still exist concerning the appropriate model for turbulence- induced phase fluctuations seen in ground-based telescopes. Bester et al. used a particular observable (slope of the Allan variance) with an infrared interferometer in an attempt to distinguish models. The authors have calculated that observable for Kolmogorov and {open_quotes}random walk{close_quotes} models with a variety of outer scales and altitude-dependent turbulence and wind velocity. The authors have found that clear distinction between models requires good data on the vertical distribution of wind and turbulence. Furthermore, measurements at time separations of order 60 s are necessary to distinguish the {open_quotes}random walk{close_quotes} model from the Kolmogorov model.

  15. Martian Meteorological Measurements Using Ground-Based Telescopes

    NASA Astrophysics Data System (ADS)

    Simpson, A.; Bailey, J.; Walter, M.; Crisp, D.

    2005-12-01

    An important component of the continuing Mars research program is the accurate determination of atmospheric and meteorological parameters, and analysis of how these parameters vary spatially and temporally. Ground-based observations are particularly useful in this regard, as they allow simultaneous global coverage and use of high-resolution spectroscopy to complement orbital measurements. Aside from the perils of atmospheric turbulence (correctable to some degree using adaptive optics), infrared observations of planetary atmospheres face another challenge -- correcting for the presence of telluric spectral lines. Based on atmospheric simulations using the SMART radiative transfer modelling tool1, we present evidence that the current technique of mitigating the effect of Earth's atmosphere by observing a nearby star of known spectral type (the ``standard star" method) can generate significant errors. Indeed, our simulations of measurements of the Martian 2-micron carbon dioxide band at a resolving power of 1000 produced variation between ``standard reduced" spectra and original modelled spectra of up to 50%2. Furthermore, we outline our proposed computational technique of iterative reduction by progressing modelled parameters towards observed values (which negates the ``standard star" issue), to be validated on data obtained from IRTF/Gemini South observations in October/November 2005, and present results to date. 1Meadows, V.S., Crisp, D., 1996, Ground-based near-infrared observations of the Venus nightside: The thermal structure and water abundance near the surface, JGR 101:E2, 4595 2Bailey, J. A., Simpson, A. J., Crisp, D., 2005, Correcting Infrared Spectra for Atmospheric Absorption, in preparation

  16. First-generation science cases for ground-based terahertz telescopes

    NASA Astrophysics Data System (ADS)

    Hirashita, Hiroyuki; Koch, Patrick M.; Matsushita, Satoki; Takakuwa, Shigehisa; Nakamura, Masanori; Asada, Keiichi; Liu, Hauyu Baobab; Urata, Yuji; Wang, Ming-Jye; Wang, Wei-Hao; Takahashi, Satoko; Tang, Ya-Wen; Chang, Hsian-Hong; Huang, Kuiyun; Morata, Oscar; Otsuka, Masaaki; Lin, Kai-Yang; Tsai, An-Li; Lin, Yen-Ting; Srinivasan, Sundar; Martin-Cocher, Pierre; Pu, Hung-Yi; Kemper, Francisca; Patel, Nimesh; Grimes, Paul; Huang, Yau-De; Han, Chih-Chiang; Huang, Yen-Ru; Nishioka, Hiroaki; Lin, Lupin Chun-Che; Zhang, Qizhou; Keto, Eric; Burgos, Roberto; Chen, Ming-Tang; Inoue, Makoto; Ho, Paul T. P.

    2016-02-01

    Ground-based observations at terahertz (THz) frequencies are a newly explorable area of astronomy in the coming decades. We discuss science cases for a first-generation 10-m class THz telescope, focusing on the Greenland Telescope as an example of such a facility. We propose science cases and provide quantitative estimates for each case. The largest advantage of ground-based THz telescopes is their higher angular resolution (˜ 4″ for a 10-m dish), as compared to space or airborne THz telescopes. Thus, high-resolution mapping is an important scientific argument. In particular, we can isolate zones of interest for Galactic and extragalactic star-forming regions. The THz windows are suitable for observations of high-excitation CO lines and [N II] 205-μm lines, which are scientifically relevant tracers of star formation and stellar feedback. Those lines are the brightest lines in the THz windows, so they are suitable for the initiation of ground-based THz observations. THz polarization of star-forming regions can also be explored since it traces the dust population contributing to the THz spectral peak. For survey-type observations, we focus on "sub-THz" extragalactic surveys, the uniqueness of which is detecting galaxies at redshifts z ˜ 1-2, where the dust emission per comoving volume is the largest in the history of the Universe. Finally we explore possibilities of flexible time scheduling, which enables us to monitor active galactic nuclei, and to target gamma-ray burst afterglows. For these objects, THz and submillimeter wavelength ranges have not yet been explored.

  17. Structure and evolution of Pluto's Atmosphere from ground-based stellar occultations between 2002 and 2015

    NASA Astrophysics Data System (ADS)

    Meza, Erick; Sicardy, Bruno; Rio de Janeiro occultation team, Granada occultation team, International Occultation and Timing Association

    2016-10-01

    Ground-Based stellar occultations probe Pluto's atmosphere from about 3 km altitude (~ 10 μbar pressure level) up to 260 km altitude (~0.1 μbar). Our main goal is to derive Pluto's atmosphere evolution using thirteen ground-based occultations observed between 2002 and 2015 (plus 2016, if available). We consistently analyze the light curves using the Dias et al. (ApJ 811, 53, 2015) model, and confirm the general pressure increase by a factor of about 1.5 between 2002 and 2015 and a factor of almost three between 1988 and 2015. Implications for Pluto's seasonal evolution will be briefly discussed in the context of the New Horizons (NH) findings.Ground-based-derived temperature profiles will be compared with NH's results, where we use new temperature boundary conditions in our inversion procedures, as given by NH near 260 km altitude. Although the profiles reasonably agree, significant discrepancies are observed both in the deeper stratospheric zone (altitude < 30 km), and the mesospheric zone (altitudes between 30 and 260 km). Possible biases will be discussed.Additionally, we use a central flash event observed in New Zealand on June 29, 2015 (close to the NH flyby) to provide an upper limit of Pluto's atmospheric oblateness near 4 km altitude. We will also explore the possibility that small deviations in the observed flash (compared to the model) are caused by the local topographic features revealed by NH.Finally, possible correlations between spike activity in the occultation light-curves and local underlying presence of free nitrogen ice terrains will be investigated.Part of the research leading to these results has received funding from the European Research Council under the European Community's H2020 (2014-2020/ ERC Grant Agreement n 669416 "LUCKY STAR").

  18. Coupled Simulations, Ground-Based Experiments and Flight Experiments for Astrodynamics Research

    NASA Astrophysics Data System (ADS)

    Boyce, R.; Brown, M.; Lorrain, P.; Capon, C.; Lambert, A.; Benson, C.; Tuttle, S.; Griffin, D.

    Near-Earth satellites undergo complex and poorly understood interactions with their environment, leading to large uncertainties in predicting orbits and an associated risk of collision with other satellites and with space debris. The nature, evolution and behaviour of the growing cloud of space debris in that environment is even less well understood. Significant effort and expenditure is currently being made by governments in Australia, UK, USA, Europe and elsewhere in space surveillance and tracking, in order to mitigate the risk. However, a major gap exists with respect to the science of in-orbit behaviour. Research is underway in Australia to enable the prediction of the orbits of near-Earth space objects with order(s) of magnitude greater fidelity than currently possible. This is being achieved by coupling together the necessary parts of the puzzle - the physics of rarefied space object “aerodynamics” and the space physics and space weather that affects it - and employing our capabilities in ground-based and in-orbit experiments, ground-based observations and high performance computing to do so. As part of the effort, UNSW Canberra is investing $10M to develop a sustainable university-led program to develop and fly affordable in-orbit missions for space research. In the coming 6 years, we will fly a minimum of four cubesat missions, some in partnership with DSTO, which will include flight experiments for validating Space Situational Awareness astrodynamics simulation and observation capabilities. The flights are underpinned by ground-based experimental research employing space test chambers, advanced diagnostics, and supercomputer simulations that couple DSMC and Particle-in-Cell methods for modelling space object interactions with the ionosphere. This paper will describe the research both underway and planned, with particular emphasis on the coupled numerical/experimental/flight approach.

  19. Ground-Based Observational Support for Spacecraft Exploration of the Outer Planets

    NASA Astrophysics Data System (ADS)

    Orton, Glenn S.

    2009-09-01

    This report presents both a retrospective of ground-based support for spacecraft missions to the outer solar system and a perspective of support for future missions. Past support is reviewed in a series of case studies involving the author. The most basic support is essential, providing the mission with information without which the planned science would not have been accomplished. Another is critical, without which science would have been returned, but missing a key element in its understanding. Some observations are enabling by accomplishing one aspect of an experiment which would otherwise not have been possible. Other observations provide a perspective of the planet as a whole which is not available to instruments with narrow fields of view and limited spatial coverage, sometimes motivating a re-prioritizing of experiment objectives. Ground-based support is also capable of providing spectral coverage not present in the complement of spacecraft instruments. Earth-based observations also have the capability of filling in gaps of spacecraft coverage of atmospheric phenomena, as well as providing surveillance of longer-term behavior than the coverage available to the mission. Future missions benefiting from ground-based support would include the Juno mission to Jupiter in the next decade, a flagship-class mission to the Jupiter or to the Saturn systems currently under consideration, and possible intermediate-class missions which might be proposed in NASA’s New Frontiers category. One of the principal benefits of future 30 m-class giant telescopes would be to improve the spatial resolution of maps of temperature and composition which are derived from observations of thermal emission at mid-infrared and longer wavelengths. In many situations, this spatial resolution is competitive with those of the relevant instruments on the spacecraft themselves.

  20. Upscaling sparse ground-based soil moisture observations for the validation of coarse-resolution satellite soil moisture products

    NASA Astrophysics Data System (ADS)

    Crow, Wade T.; Berg, Aaron A.; Cosh, Michael H.; Loew, Alexander; Mohanty, Binayak P.; Panciera, Rocco; de Rosnay, Patricia; Ryu, Dongryeol; Walker, Jeffrey P.

    2012-06-01

    The contrast between the point-scale nature of current ground-based soil moisture instrumentation and the ground resolution (typically >102 km2) of satellites used to retrieve soil moisture poses a significant challenge for the validation of data products from current and upcoming soil moisture satellite missions. Given typical levels of observed spatial variability in soil moisture fields, this mismatch confounds mission validation goals by introducing significant sampling uncertainty in footprint-scale soil moisture estimates obtained from sparse ground-based observations. During validation activities based on comparisons between ground observations and satellite retrievals, this sampling error can be misattributed to retrieval uncertainty and spuriously degrade the perceived accuracy of satellite soil moisture products. This review paper describes the magnitude of the soil moisture upscaling problem and measurement density requirements for ground-based soil moisture networks. Since many large-scale networks do not meet these requirements, it also summarizes a number of existing soil moisture upscaling strategies which may reduce the detrimental impact of spatial sampling errors on the reliability of satellite soil moisture validation using spatially sparse ground-based observations.

  1. Using the FLUKA Monte Carlo Code to Simulate the Interactions of Ionizing Radiation with Matter to Assist and Aid Our Understanding of Ground Based Accelerator Testing, Space Hardware Design, and Secondary Space Radiation Environments

    NASA Technical Reports Server (NTRS)

    Reddell, Brandon

    2015-01-01

    Designing hardware to operate in the space radiation environment is a very difficult and costly activity. Ground based particle accelerators can be used to test for exposure to the radiation environment, one species at a time, however, the actual space environment cannot be duplicated because of the range of energies and isotropic nature of space radiation. The FLUKA Monte Carlo code is an integrated physics package based at CERN that has been under development for the last 40+ years and includes the most up-to-date fundamental physics theory and particle physics data. This work presents an overview of FLUKA and how it has been used in conjunction with ground based radiation testing for NASA and improve our understanding of secondary particle environments resulting from the interaction of space radiation with matter.

  2. Active seat suspension for a small vehicle: considerations for control system including observer

    NASA Astrophysics Data System (ADS)

    Katsumata, Hiroyuki; Shiino, Hiroshi; Oshinoya, Yasuo; Ishibashi, Kazuhisa; Ozaki, Koichi; Ogino, Hirohiko

    2007-12-01

    We have examined the improvement of ride quality and the reduction of riding fatigue brought about by the active control of the seat suspension of small vehicles such as one-seater electric automobiles. A small active seat suspension, which is easy to install, was designed and manufactured for one-seater electric automobiles. For the actuator, a maintenance-free voice coil motor used as a direct drive was adopted. For fundamental considerations, we designed a one-degree-of-freedom model for the active seat suspension system. Then, we designed a disturbance cancellation control system that includes the observer for a two-degree-of-freedom model. In an actual driving test, a test road, in which the concavity and convexity of an actual road surface were simulated using hard rubber, was prepared and the control performance of vertical vibrations of the seat surface during driving was examined. As a result, in comparison with the one-degree-of-freedom control system, it was confirmed that the control performance was improved by the two-degree-of-freedom control system that includes the observer.

  3. Monitoring Precipitation Contents and Extinction By Using A Ground-based Passive Microwave Technique

    NASA Astrophysics Data System (ADS)

    Marzano, F. S.; Fionda, E.; Ciotti, P.; Consalvi, F.

    In the last decades microwave radiometry has proved to be a valuable tool for retriev- ing atmospheric parameters both from ground-based and from satellite-borne plat- forms. Ground-based microwave radiometry has been mainly investigated for esti- mating temperature, water vapor and cloud liquid profiles in the absence of precip- itation. However, the increasing use of multifrequency radiometers in ground-based stations, especially for communication purposes, rises the question of their potential for retrieving also rainfall rate from ground. This capability might be also useful when weather radars are also present, since radiometric estimates might be used as a further constraint within the radar inversion procedure. One of the main problems of ground- based radiometry for rainfall retrieval is the possible impact of water layers on the receiving antenna whose measurements can be heavily contaminated. The estimate of atmospheric parameters by microwave radiometry may be approached by using both experimental and simulated data. The use of experimental measurements is limited by their scarcity or even their lack. The modeling approach is generally more versatile, even though it requests a thorough insight into the e.m. interaction between the mi- crowave radiation and the scattering medium. The radiative transfer theory has been so far the most used approach to take into account multiple scattering and vertical inho- mogeneity of the atmosphere in the presence of hydrometeor scattering. Following a previous work, the objective of this paper is to investigate about radiometric frequency sets and system configurations best suited for observing both stratiform and convective precipitation. We develop inversion algorithms for ground-based retrieval of surface rainrate, adopting a model-based approach. For both stratiform and convective precip- itation, we use a radiative transfer model (RTM), including spherical liquid, melt and ice hydrometeors. From the solution of

  4. Proceedings of the 2010 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    SciTech Connect

    Wetovsky, Marvin A; Patterson, Eileen F

    2010-09-21

    These proceedings contain papers prepared for the Monitoring Research Review 2010: Ground-Based Nuclear Explosion Monitoring Technologies, held 21-23 September, 2010 in Orlando, Florida,. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, National Science Foundation (NSF), Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  5. Proceedings of the 2009 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    SciTech Connect

    Wetovsky, Marv A; Aguilar - Chang, Julio; Anderson, Dale; Arrowsmith, Marie; Arrowsmith, Stephen; Baker, Diane; Begnaud, Michael; Harste, Hans; Maceira, Monica; Patton, Howard; Phillips, Scott; Randall, George; Rowe, Charlotte; Stead, Richard; Steck, Lee; Whitaker, Rod; Yang, Xiaoning

    2009-09-21

    These proceedings contain papers prepared for the Monitoring Research Review 2009: Ground -Based Nuclear Explosion Monitoring Technologies, held 21-23 September, 2009 in Tucson, Arizona,. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Test Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States’ capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  6. Proceedings of the 30th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring

    SciTech Connect

    Wetovsky, Marv A; Aguilar-chang, Julio; Arrowsmith, Marie; Arrowsmith, Stephen; Baker, Diane; Begnaud, Michael; Harste, Hans; Maceira, Monica; Patton, Howard; Phillips, Scott; Randall, George; Revelle, Douglas; Rowe, Charlotte; Stead, Richard; Steck, Lee; Whitaker, Rod; Yang, Xiaoning

    2008-09-23

    These proceedings contain papers prepared for the 30th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 23-25 September, 2008 in Portsmouth, Virginia. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States’ capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  7. Proceedings of the 27th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    SciTech Connect

    Wetovsky, Marvin A.; Benson, Jody; Patterson, Eileen F.

    2005-09-20

    These proceedings contain papers prepared for the 27th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 20-22 September, 2005 in Rancho Mirage, California. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  8. Proceedings of the 2011 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    SciTech Connect

    Wetovsky, Marvin A.; Patterson, Eileen F.; Sandoval, Marisa N.

    2011-09-13

    These proceedings contain papers prepared for the Monitoring Research Review 2011: Ground-Based Nuclear Explosion Monitoring Technologies, held 13-15 September, 2011 in Tucson, Arizona. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), National Science Foundation (NSF), and other invited sponsors. The scientific objectives of the research are to improve the United States' capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  9. Proceedings of the 29th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    SciTech Connect

    Wetovsky, Marvin A.; Benson, Jody; Patterson, Eileen F.

    2007-09-25

    These proceedings contain papers prepared for the 29th Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 25-27 September, 2007 in Denver, Colorado. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  10. Proceedings of the 28th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies

    SciTech Connect

    Wetovsky, Marvin A.; Benson, Jody; Patterson, Eileen F.

    2006-09-19

    These proceedings contain papers prepared for the 28th Seismic Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, held 19-21 September, 2006 in Orlando, Florida. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Air Force Technical Applications Center (AFTAC), Air Force Research Laboratory (AFRL), US Army Space and Missile Defense Command, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.

  11. Capabilities and constraints of NASA's ground-based reduced gravity facilities

    NASA Technical Reports Server (NTRS)

    Lekan, Jack; Neumann, Eric S.; Sotos, Raymond G.

    1993-01-01

    The ground-based reduced gravity facilities of NASA have been utilized to support numerous investigations addressing various processes and phenomina in several disciplines for the past 30 years. These facilities, which include drop towers, drop tubes, aircraft, and sounding rockets are able to provide a low gravity environment (gravitational levels that range from 10(exp -2)g to 10(exp -6)g) by creating a free fall or semi-free fall condition where the force of gravity on an experiment is offset by its linear acceleration during the 'fall' (drop or parabola). The low gravity condition obtained on the ground is the same as that of an orbiting spacecraft which is in a state of perpetual free fall. The gravitational levels and associated duration times associated with the full spectrum of reduced gravity facilities including spaced-based facilities are summarized. Even though ground-based facilities offer a relatively short experiment time, this available test time has been found to be sufficient to advance the scientific understanding of many phenomena and to provide meaningful hardware tests during the flight experiment development process. Also, since experiments can be quickly repeated in these facilities, multistep phenomena that have longer characteristic times associated with them can sometimes be examined in a step-by-step process. There is a large body of literature which has reported the study results achieved through using reduced-gravity data obtained from the facilities.

  12. Optical/infrared views of the distant universe with ground-based telescopes

    NASA Astrophysics Data System (ADS)

    Gallagher, J. S.; Tolstoy, E.

    1997-05-01

    Ground-based optical/IR observatories offer access to the rest frame ultraviolet and visible spectral regions of objects with high redshifts. Current observations of high redshift objects with natural seeing of 0.5-1 arcsec include optical/IR photometry and a variety of spectroscopic measurements. These take advantage of the large apertures and efficient instruments of ground-based observatories to obtain high spectral resolution and to reach low surface brightnesses, which is required to overcome cosmological effects. The success of natural guide star adaptive optics systems suggests that observations could become routine with image diameters <=0.25 arcsec (and often approaching 0.1 arcsec) over modest fields of view in the IJHK bands. The combination of adaptive optics on 8-10-m class telescopes, versatile arrays of powerful instruments (including multi-slit or integral field unit spectrographs), and airglow suppression schemes will support deeper and more intensive infrared investigations of faint galaxies, and will allow us to take advantage of increased brightness in strong emission lines. This work should lead to a better understanding of selection effects at high redshift, as well as the identification and measurement of internal properties for typical galaxies at early epochs.

  13. Coordinated THEMIS and ground-based magnetometer study of ULF wave excitation during a fast solar wind stream

    NASA Astrophysics Data System (ADS)

    Mann, Ian; Rae, Jonathan; Larson, Davin; Glassmeier, Karl-Heinz; Bonnell, J. W.; Kale, Zoe; McFadden, James; Singer, Howard; Angelopoulos, V.; Russell, Christopher; Auster, Uli; Mende, Stephen

    AB: We present results from a study of ULF waves observed during a conjunction between the THEMIS constellation and ground-based magnetometers of the combined CARISMA and THEMIS ground-based observatory (GBO) arrays during a fast solar wind stream in August 2007. Long wavetrain waves in the Pc4 and Pc5 bands were seen across the ground-based arrays during a conjugate overpass of the THEMIS constellation in the dusk magnetosphere over CARISMA on August 8th. The Pc4 waves, also seen on THEMIS, were very monochromatic with many characteristics reminiscent of giant pulsations (Pgs) except that they occurred in the dusk sector. The multiple satellite measurements, including supporting measurements from GOES satellites in this sector, allow characterization of the wavenumbers, spatial scale, and comparison of the widths of the waves on the ground and in space. The monochromatic nature of the Pc4 waves, and their dominant polarization in the D-component on the ground, suggests that they are poloidal Alfven waves perhaps driven by injected ions in the afternoon-side magnetosphere. We use the unique capabilities of the combined THEMIS-GOES constellation, and the extensive ground-based coverage, to address the issue of the source of wave excitation during this high speed stream. Attention is given to internal excitation by energetic ions spectra.

  14. Coordinated THEMIS and ground-based magnetometer study of ULF wave excitation during a fast solar wind stream

    NASA Astrophysics Data System (ADS)

    Mann, I. R.; Rae, I. J.; Glassmeier, K.; Mende, S. B.; Angelopoulos, V.; Auster, U.; Russell, C. T.; Singer, H. J.; Bonnell, J. W.; Mozer, F. S.; Larson, D.; Carlson, C.; McPhadden, J.

    2007-12-01

    We present results from a study of ULF waves observed during a conjunction between the THEMIS constellation and ground-based magnetometers of the combined CARISMA and THEMIS ground-based observatory (GBO) arrays during a fast solar wind stream in August 2007. Long wavetrain waves in the Pc4 and Pc5 bands were seen across the ground-based arrays during a conjugate overpass of the THEMIS constellation in the dusk magnetosphere over CARISMA on August 8th. The Pc4 waves, also seen on THEMIS, were very monochromatic with many characteristics reminiscent of giant pulsations (Pgs) except that they occurred in the dusk sector. The multiple satellite measurements, including supporting measurements from GOES satellites in this sector, allow characterization of the wavenumbers, spatial scale, and comparison of the widths of the waves on the ground and in space. The monochromatic nature of the Pc4 waves, and their dominant polarization in the D-component on the ground, suggests that they are poloidal Alfven waves perhaps driven by injected ions in the afternoon-side magnetosphere. We use the unique capabilities of the combined THEMIS-GOES constellation, and the extensive ground-based coverage, to address the issue of the source of wave excitation during this high speed stream. Attention is given to internal excitation by energetic ions spectra, and drivers at the dayside magnetopause.

  15. Comparing ground-based and airborne aerosol measurements during the Houston and Colorado DISCOVER-AQ field deployments

    NASA Astrophysics Data System (ADS)

    Thornhill, K. L., II; Anderson, B. E.; Ziemba, L. D.; Beyersdorf, A. J.; Winstead, E.; Moore, R.; Shook, M.; Corr, C.; Chen, G.; Hudgins, C.; Barrick, J. D. W.; Martin, R.; Jordan, C. E.; Brown, M.; Hite, J. R.; Nenes, A.

    2014-12-01

    Understanding the relationship between airborne and ground-based measurements is one of the key questions that the DISCOVER-AQ series of field deployments hope to be able to answer. To address this question, the NASA P-3B systematically conducted vertical profiles over at least six ground sites sampling down to about 1000 feet over ground level. This data is combined with missed approaches at local airports which provide vertically resolved information between the lowest spiral altitude and the ground-based measurements. During the last two DISCOVER-AQ field deployments (Houston September 2013 and Colorado (July-August 2014), NASA Langley had aerosol measurements both onboard the NASA P-3B and in a mobile laboratory. Coincident measurements included aerosol number concentration, size distributions, along with optical properties such as aerosol scattering, extinction, and hygroscopicity. We present a comparison between the airborne and ground-based measurements made in two very different environments. The Houston area had much higher aerosol concentrations we sampled a variety of airmasses, from clean marine-air to emissions from the local refineries. In Colorado, most of the sampling was done in low aerosol concentration environments, away from local sources. Combined, the two field experiments provide at least 60 comparisons between airborne and ground-based aerosol measurements.

  16. Enzymatically active 2',5'-oligoadenylate synthetases are widely distributed among Metazoa, including protostome lineage.

    PubMed

    Päri, Mailis; Kuusksalu, Anne; Lopp, Annika; Kjaer, Karina Hansen; Justesen, Just; Kelve, Merike

    2014-02-01

    2',5'-Oligoadenylate synthetases (OASs) belong to the nucleotidyl transferase family together with poly(A) polymerases, CCA-adding enzymes and the recently discovered cyclic-GMP-AMP synthase (cGAS). Mammalian OASs have been thoroughly characterized as components of the interferon-induced antiviral system. The OAS activity and the respective genes were also discovered in marine sponges where the interferon system is absent. In this study the recombinant OASs from several multicellular animals and their closest unicellular relative, a choanoflagellate, were expressed in a bacterial expression system and their enzymatic activities were examined. We demonstrated 2-5A synthesizing activities of OASs from the marine sponge Tedania ignis, a representative of the phylogenetically oldest metazoan phylum (Porifera), from an invertebrate of the protostome lineage, the mollusk Mytilus californianus (Mollusca), and from a vertebrate species, a cartilaginous fish Leucoraja erinacea (Chordata). However, the expressed proteins from an amphibian, the salamander Ambystoma mexicanum (Chordata), and from a protozoan, the marine choanoflagellate Monosiga brevicollis (Choanozoa), did not show 2-5A synthesizing activity. Differently from other studied OASs, OAS from the marine sponge T. ignis was able to catalyze the formation of oligomers having both 2',5'- and 3',5'-phosphodiester linkages. Our data suggest that OASs from sponges and evolutionarily higher animals have similar activation mechanisms which still include different affinities and possibly different structural requirements for the activating RNAs. Considering their 2'- and 3'-specificities, sponge OASs could represent a link between evolutionarily earlier nucleotidyl transferases and 2'-specific OASs from higher animals.

  17. Enzymatically active 2',5'-oligoadenylate synthetases are widely distributed among Metazoa, including protostome lineage.

    PubMed

    Päri, Mailis; Kuusksalu, Anne; Lopp, Annika; Kjaer, Karina Hansen; Justesen, Just; Kelve, Merike

    2014-02-01

    2',5'-Oligoadenylate synthetases (OASs) belong to the nucleotidyl transferase family together with poly(A) polymerases, CCA-adding enzymes and the recently discovered cyclic-GMP-AMP synthase (cGAS). Mammalian OASs have been thoroughly characterized as components of the interferon-induced antiviral system. The OAS activity and the respective genes were also discovered in marine sponges where the interferon system is absent. In this study the recombinant OASs from several multicellular animals and their closest unicellular relative, a choanoflagellate, were expressed in a bacterial expression system and their enzymatic activities were examined. We demonstrated 2-5A synthesizing activities of OASs from the marine sponge Tedania ignis, a representative of the phylogenetically oldest metazoan phylum (Porifera), from an invertebrate of the protostome lineage, the mollusk Mytilus californianus (Mollusca), and from a vertebrate species, a cartilaginous fish Leucoraja erinacea (Chordata). However, the expressed proteins from an amphibian, the salamander Ambystoma mexicanum (Chordata), and from a protozoan, the marine choanoflagellate Monosiga brevicollis (Choanozoa), did not show 2-5A synthesizing activity. Differently from other studied OASs, OAS from the marine sponge T. ignis was able to catalyze the formation of oligomers having both 2',5'- and 3',5'-phosphodiester linkages. Our data suggest that OASs from sponges and evolutionarily higher animals have similar activation mechanisms which still include different affinities and possibly different structural requirements for the activating RNAs. Considering their 2'- and 3'-specificities, sponge OASs could represent a link between evolutionarily earlier nucleotidyl transferases and 2'-specific OASs from higher animals. PMID:24184688

  18. Plants as sources of airborne bacteria, including ice nucleation-active bacteria.

    PubMed

    Lindemann, J; Constantinidou, H A; Barchet, W R; Upper, C D

    1982-11-01

    Vertical wind shear and concentration gradients of viable, airborne bacteria were used to calculate the upward flux of viable cells above bare soil and canopies of several crops. Concentrations at soil or canopy height varied from 46 colony-forming units per m over young corn and wet soil to 663 colony-forming units per m over dry soil and 6,500 colony-forming units per m over a closed wheat canopy. In simultaneous samples, concentrations of viable bacteria in the air 10 m inside an alfalfa field were fourfold higher than those over a field with dry, bare soil immediately upwind. The upward flux of viable bacteria over alfalfa was three- to fourfold greater than over dry soil. Concentrations of ice nucleation-active bacteria were higher over plants than over soil. Thus, plant canopies may constitute a major source of bacteria, including ice nucleation-active bacteria, in the air.

  19. The Future of European Collaborations in Ground-based Astronomy and the Role of OPTICON

    NASA Astrophysics Data System (ADS)

    Dennefeld, M.

    2007-05-01

    Successfull projects like the ESO-VLT have shown the power of large scale collaboration in Europe. Such collaborations continue to be needed today to develop the Extremely Large Telescopes of the future or to coordinate the use and development of ``smaller" facilities. The OPTICON network, funded by the European Union under FP6, plays a major role of coordination for ground-based optical/IR astronomy in Europe. It comprises Joint Research Activities dealing with various, high-technology activities; thematic networks where plans are made for future activities, new ideas discussed or existing infrastructures are coordinated; and an Access programme where most of the modern, medium-sized European observatories are offered to foreign users on the basis of the scientific quality of the proposals only. This latter opportunity should be of great interest to the solar and stellar astronomers assembled for this symposium.

  20. Measuring and Reducing Off-Target Activities of Programmable Nucleases Including CRISPR-Cas9.

    PubMed

    Koo, Taeyoung; Lee, Jungjoon; Kim, Jin-Soo

    2015-06-01

    Programmable nucleases, which include zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and RNA-guided engineered nucleases (RGENs) repurposed from the type II clustered, regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system are now widely used for genome editing in higher eukaryotic cells and whole organisms, revolutionising almost every discipline in biological research, medicine, and biotechnology. All of these nucleases, however, induce off-target mutations at sites homologous in sequence with on-target sites, limiting their utility in many applications including gene or cell therapy. In this review, we compare methods for detecting nuclease off-target mutations. We also review methods for profiling genome-wide off-target effects and discuss how to reduce or avoid off-target mutations.

  1. Probing Pluto's Atmosphere Using Ground-Based Stellar Occultations

    NASA Astrophysics Data System (ADS)

    Sicardy, Bruno; Rio de Janeiro Occultation Team, Granada Team, International Occultation and Timing Association, Royal Astronomical Society New Zealand Occultation Section, Lucky Star associated teams

    2016-10-01

    Over the last three decades, some twenty stellar occultations by Pluto have been monitored from Earth. They occur when the dwarf planet blocks the light from a star for a few minutes as it moves on the sky. Such events led to the hint of a Pluto's atmosphere in 1985, that was fully confirmed during another occultation in 1988, but it was only in 2002 that a new occultation could be recorded. From then on, the dwarf planet started to move in front of the galactic center, which amplified by a large factor the number of events observable per year.Pluto occultations are essentially refractive events during which the stellar rays are bent by the tenuous atmosphere, causing a gradual dimming of the star. This provides the density, pressure and temperature profiles of the atmosphere from a few kilometers above the surface up to about 250 km altitude, corresponding respectively to pressure levels of about 10 and 0.1 μbar. Moreover, the extremely fine spatial resolution (a few km) obtained through this technique allows the detection of atmospheric gravity waves, and permits in principle the detection of hazes, if present.Several aspects make Pluto stellar occultations quite special: first, they are the only way to probe Pluto's atmosphere in detail, as the dwarf planet is far too small on the sky and the atmosphere is far too tenuous to be directly imaged from Earth. Second, they are an excellent example of participative science, as many amateurs have been able to record those events worldwide with valuable scientific returns, in collaboration with professional astronomers. Third, they reveal Pluto's climatic changes on decade-scales and constrain the various seasonal models currently explored.Finally, those observations are fully complementary to space exploration, in particular with the New Horizons (NH) mission. I will show how ground-based occultations helped to better calibrate some NH profiles, and conversely, how NH results provide some key boundary conditions

  2. Independet Component Analyses of Ground-based Exoplanetary Transits

    NASA Astrophysics Data System (ADS)

    Silva Martins-Filho, Walter; Griffith, Caitlin Ann; Pearson, Kyle; Waldmann, Ingo; Biddle, Lauren; Zellem, Robert Thomas; Alvarez-Candal, Alvaro

    2016-10-01

    Most observations of exoplanetary atmospheres are conducted when a "Hot Jupiter" exoplanet transits in front of its host star. These Jovian-sized planets have small orbital periods, on the order of days, and therefore a short transit time, making them more ameanable to observations. Measurements of Hot Jupiter transits must achieve a 10-4 level of accuracy in the flux to determine the spectral modulations of the exoplanetary atmosphere. In order to accomplish this level of precision, we need to extract systematic errors, and, for ground-based measurements, the effects of Earth's atmosphere, from the signal due to the exoplanet, which is several orders of magnitudes smaller. Currently, the effects of the terrestrial atmosphere and the some of the time-dependent systematic errors are treated by dividing the host star by a reference star at each wavelength and time step of the transit. More recently, Independent Component Analyses (ICA) have been used to remove systematic effects from the raw data of space-based observations (Waldmann 2014,2012; Morello et al.,2015,2016). ICA is a statistical method born from the ideas of the blind-source separation studies, which can be used to de-trend several independent source signals of a data set (Hyvarinen and Oja, 2000). One strength of this method is that it requires no additional prior knowledge of the system. Here, we present a study of the application of ICA to ground-based transit observations of extrasolar planets, which are affected by Earth's atmosphere. We analyze photometric data of two extrasolar planets, WASP-1b and GJ3470b, recorded by the 61" Kuiper Telescope at Stewart Observatory using the Harris B and U filters. The presentation will compare the light curve depths and their dispersions as derived from the ICA analysis to those derived by analyses that ratio of the host star to nearby reference stars.References: Waldmann, I.P. 2012 ApJ, 747, 12, Waldamann, I. P. 2014 ApJ, 780, 23; Morello G. 2015 ApJ, 806

  3. Ground-based testing of space nuclear power plants

    SciTech Connect

    McDonald, T.G.

    1990-10-22

    Small nuclear power plants for space applications are evaluated according to their testability in this two part report. The first part introduces the issues involved in testing these power plants. Some of the concerns include oxygen embrittlement of critical components, the test environment, the effects of a vacuum environment on materials, the practically of racing an activated test chamber, and possible testing alternative the SEHPTR, king develop at the Idaho National Engineering Laboratory. 10 refs., 6 figs., 1 tab.

  4. Stability and activity of alcohol dehydrogenases in W/O-microemulsions: enantioselective reduction including cofactor regeneration.

    PubMed

    Orlich, B; Berger, H; Lade, M; Schomäcker, R

    2000-12-20

    Microemulsions provide an interesting alternative to classical methods for the conversion of less water-soluble substrates by alcohol dehydrogenase, but until now stability and activity were too low for economically useful processes. The activity and stability of the enzymes are dependent on the microemulsion composition, mostly the water and the surfactant concentration. Therefore, it is necessary to know the exact phase behavior of a given microemulsion reaction system and the corresponding enzyme behavior therein. Because of their economic and ecologic suitability polyethoxylated fatty alcohols were investigated concerning their phase behavior and their compatibility with enzymes in ternary mixtures. The phase behavior of Marlipal O13-60 (C13EO6 in industrial quality)/cyclohexane/water and its effect on the activity and stability of alcohol dehydrogenase from Yeast (YADH) and horse liver (HLADH) and the carbonyl reductase from Candida parapsilosis (CPCR) is presented in this study. Beside the macroscopic phase behavior of the reaction system, the viscosity of the system indicates structural changes of aggregates in the microemulsion. The changes of the enzyme activities with the composition are discussed on the basis of transitions from reverse micelles to swollen reverse micelles and finally, the transition to the phase separation. The formate dehydrogenase from Candida boidinii was used for the NADH-regeneration during reduction reactions. While the formate dehydrogenase did not show any kinetic effect on the microemulsion composition, the other enzymes show significant changes of activity and stability varying the water or surfactant concentration of the microemulsion. Under certain conditions, stability could be maintained with HLADH for several weeks. Successful experiments with semi-batch processes including cofactor regeneration and product separation were performed.

  5. Synchronized observations by using the STEREO and the largest ground-based decametre radio telescope

    NASA Astrophysics Data System (ADS)

    Konovalenko, A. A.; Stanislavsky, A. A.; Rucker, H. O.; Lecacheux, A.; Mann, G.; Bougeret, J.-L.; Kaiser, M. L.; Briand, C.; Zarka, P.; Abranin, E. P.; Dorovsky, V. V.; Koval, A. A.; Mel'nik, V. N.; Mukha, D. V.; Panchenko, M.

    2013-08-01

    We consider the approach to simultaneous (synchronous) solar observations of radio emission by using the STEREO-WAVES instruments (frequency range 0.125-16 MHz) and the largest ground-based low-frequency radio telescope. We illustrate it by the UTR-2 radio telescope implementation (10-30 MHz). The antenna system of the radio telescope is a T-shape-like array of broadband dipoles and is located near the village Grakovo in the Kharkiv region (Ukraine). The third observation point on the ground in addition to two space-based ones improves the space-mission performance capabilities for the determination of radio-emission source directivity. The observational results from the high sensitivity antenna UTR-2 are particularly useful for analysis of STEREO data in the condition of weak event appearances during solar activity minima. In order to improve the accuracy of flux density measurements, we also provide simultaneous observations with a large part of the UTR-2 radio telescope array and its single dipole close to the STEREO-WAVES antennas in sensitivity. This concept has been studied by comparing the STEREO data with ground-based records from 2007-2011 and shown to be effective. The capabilities will be useful in the implementation of new instruments (LOFAR, LWA, MWA, etc.) and during the future Solar Orbiter mission.

  6. Phobos and Deimos. [ground based and spacecraft observations

    NASA Technical Reports Server (NTRS)

    Pollack, J. B.

    1977-01-01

    Ground-based and spacecraft observations of Phobos and Deimos are reviewed and the satellites' origin is discussed. The crater densities of both bodies are close to the saturation level. The largest impact events may have caused extensive fracturing of their surfaces. The surfaces are at least 1.5 billion years old and may date back to the early history of the solar system. The Martian satellites display large deviations from sphericity. As a result of tidal processes, they are in synchronous rotation. Several independent lines of evidence show that they have regoliths. Despite some provocative arguments, their internal strengths and the nature of their interior are poorly known at present. Photometric measurements suggest that they are made of either carbonaceous chondritic material or a basalt. Sinclair (1972), Born and Duxbury (1975) and Shor (1975) apparently have successfully determined Phobos' secular acceleration. Their value of approximately .001 deg/year/year implies that the interior of Mars has a low specific dissipation factor (about 100), may indicate that a portion of the Martian interior is experiencing partial melting. The low inclination of the satellites' orbits indicates that they were formed as part of the same process that resulted in Mars.

  7. A comparative study of satellite and ground-based phenology.

    PubMed

    Studer, S; Stöckli, R; Appenzeller, C; Vidale, P L

    2007-05-01

    Long time series of ground-based plant phenology, as well as more than two decades of satellite-derived phenological metrics, are currently available to assess the impacts of climate variability and trends on terrestrial vegetation. Traditional plant phenology provides very accurate information on individual plant species, but with limited spatial coverage. Satellite phenology allows monitoring of terrestrial vegetation on a global scale and provides an integrative view at the landscape level. Linking the strengths of both methodologies has high potential value for climate impact studies. We compared a multispecies index from ground-observed spring phases with two types (maximum slope and threshold approach) of satellite-derived start-of-season (SOS) metrics. We focus on Switzerland from 1982 to 2001 and show that temporal and spatial variability of the multispecies index correspond well with the satellite-derived metrics. All phenological metrics correlate with temperature anomalies as expected. The slope approach proved to deviate strongly from the temporal development of the ground observations as well as from the threshold-defined SOS satellite measure. The slope spring indicator is considered to indicate a different stage in vegetation development and is therefore less suited as a SOS parameter for comparative studies in relation to ground-observed phenology. Satellite-derived metrics are, however, very susceptible to snow cover, and it is suggested that this snow cover should be better accounted for by the use of newer satellite sensors.

  8. Development of a Compact, Ground-Based Ozone DIAL System

    NASA Technical Reports Server (NTRS)

    Chyba, T. H.; Zenker, T.; McCray, C. L.; Lee, H. R.; Thomas, B.; Elivert, R.; Higdon, N. Scott; Richter, D. A.; Fishman, J.

    1998-01-01

    We are developing a portable, eye-safe, ground-based ozone lidar instrument specialized for ozone differential absorption lidar (DIAL) measurements in the troposphere. This prototype instrument is intended to operate at remote field sites and to serve as the basic unit for future monitoring projects requiring multi-instrument networks, such as that proposed for the Global Tropospheric Ozone Project (GTOP). GTOP is currently being formulated by a scientific panel of the International Global Atmospheric Chemistry Project to meet its goal to better understand the processes that control the global distribution of tropospheric ozone. In order for the lidar to be widely deployed in networks, it must be fairly easy to use and maintain as well as being cost-competitive with ground station launching ozone sondes which operate several times a day. To achieve these goals, emphasis is placed upon the incorporation of: (1) all-solid state transmitters which can reliably produce 20-40 mJ pulses; (2) a highly efficient, narrow-bandpass receiver; (3) dual analog and photon-counting detector channels; and (4) flexible, user-friendly control software.

  9. Nonlinear analysis of the ground-based magnetometer network

    NASA Astrophysics Data System (ADS)

    DiTommaso, Joseph Henry

    When the first magnetometer was created by Frederick Gauss in 1833, scientists gained a powerful tool for studying the structure, dynamics, and strength of the Earth's magnetic field: the magnetosphere. Since Gauss' time, the world's scientific community has established ground-based magnetometer stations around the globe in an effort to study local and global perturbations and patterns of the Earth's magnetic field. The main focus of this network has been monitoring the magnetic flux and impact from the Sun's constant outflow of radiation and particles known as the solar wind, as well as its more violent eruptive events. There has been little work, by comparison, into the signals and correlations within the network itself. Since the Earth's field can roughly be mapped to a dipole and disturbances often have a large scale structure, one can surmise there should be some correlation between stations based on their relative positions to one another. What that correlation is or represents is not clear. To investigate this possible correlation and its nature, a set of nonlinear analytic methods were conducted on magnetic data collected from stations scattered across North America over an 18 year period. The analysis was focused on searching for spatial and temporal correlations of nonperiodic signals in the magnetometer network. The findings from that analysis suggest there exist nonlocal correlations between stations that are dependent on position, which could be useful in the development of a space weather risk assessment.

  10. Ground-based testing and demonstrations of starshades

    NASA Astrophysics Data System (ADS)

    Harness, Anthony; Warwick, Steve; Shipley, Ann; Cash, Webster

    2016-07-01

    The direct detection and characterization of an Earth-like exoplanet is of the highest scientific priority and a leading technology that will enable such discovery is the starshade external occulter. We report on the latest results in ground-based efforts for demonstrating and advancing the technology of starshades. Using the McMath- Pierce Solar Telescope at the Kitt Peak National Observatory, we are able to track stars as they move across the night sky and stabilize a beam of starlight behind a starshade. This has allowed us to conduct the first astronomical observations achieving high-contrast with starshades. In our latest efforts, we have extended the separation between the starshade and telescope to reach an inner working angle of 10 arcseconds at a flight-like Fresnel number and resolution. In this report, we detail the development of a closed-loop feedback system to further stabilize the beam at the extended baseline and provide results on the contrast achieved. We conclude by laying out future work to design a dedicated siderostat-starshade facility for future testing of and observations with starshades. Our main result: we achieved a broadband contrast ratio of 3:2 x 10-5 at 15 arcseconds IWA, while at a flight-like Fresnel number and resolution.

  11. Bridge Testing With Ground-Based Interferometric Radar: Experimental Results

    SciTech Connect

    Chiara, P.; Morelli, A.

    2010-05-28

    The research of innovative non-contact techniques aimed at the vibration measurement of civil engineering structures (also for damage detection and structural health monitoring) is continuously directed to the optimization of measures and methods. Ground-Based Radar Interferometry (GBRI) represents the more recent technique available for static and dynamic control of structures and ground movements.Dynamic testing of bridges and buildings in operational conditions are currently performed: (a) to assess the conformity of the structure to the project design at the end of construction; (b) to identify the modal parameters (i.e. natural frequencies, mode shapes and damping ratios) and to check the variation of any modal parameters over the years; (c) to evaluate the amplitude of the structural response to special load conditions (i.e. strong winds, earthquakes, heavy railway or roadway loads). If such tests are carried out by using a non-contact technique (like GBRI), the classical issues of contact sensors (like accelerometers) are easily overtaken.This paper presents and discusses the results of various tests carried out on full-scale bridges by using a Stepped Frequency-Continuous Wave radar system.

  12. Assuring Ground-Based Detect and Avoid for UAS Operations

    NASA Technical Reports Server (NTRS)

    Denney, Ewen W.; Pai, Ganeshmadhav Jagadeesh; Berthold, Randall; Fladeland, Matthew; Storms, Bruce; Sumich, Mark

    2014-01-01

    One of the goals of the Marginal Ice Zones Observations and Processes Experiment (MIZOPEX) NASA Earth science mission was to show the operational capabilities of Unmanned Aircraft Systems (UAS) when deployed on challenging missions, in difficult environments. Given the extreme conditions of the Arctic environment where MIZOPEX measurements were required, the mission opted to use a radar to provide a ground-based detect-and-avoid (GBDAA) capability as an alternate means of compliance (AMOC) with the see-and-avoid federal aviation regulation. This paper describes how GBDAA safety assurance was provided by interpreting and applying the guidelines in the national policy for UAS operational approval. In particular, we describe how we formulated the appropriate safety goals, defined the processes and procedures for system safety, identified and assembled the relevant safety verification evidence, and created an operational safety case in compliance with Federal Aviation Administration (FAA) requirements. To the best of our knowledge, the safety case, which was ultimately approved by the FAA, is the first successful example of non-military UAS operations using GBDAA in the U.S. National Airspace System (NAS), and, therefore, the first nonmilitary application of the safety case concept in this context.

  13. Cardiovascular effects of weightlessness and ground-based simulation

    NASA Technical Reports Server (NTRS)

    Sandler, Harold

    1988-01-01

    A large number of animal and human flight and ground-based studies were conducted to uncover the cardiovascular effects of weightlessness. Findings indicate changes in cardiovascular function during simulations and with spaceflight that lead to compromised function on reambulation and/or return to earth. This altered state termed cardiovascular deconditioning is most clearly manifest when in an erect body state. Hemodynamic parameters inidicate the presence of excessive tachnycardia, hypotension (leading to presyncope in one-third of the subjects), decreased heart volume, decreased plasma and circulating blood volumes and loss of skeletal muscle mass, particularly in the lower limbs. No clinically harmful effects were observed to date, but in-depth follow-ups were limited, as was available physiologic information. Available data concerning the causes for the observed changes indicate significant roles for mechanisms involved with body fluid-volume regulation, altered cardiac function, and the neurohumoral control of the control of the peripheral circulation. Satisfactory measures are not found. Return to preflight state was variable and only slightly dependent on flight duration. Future progress awaits availability of flight durations longer than several weeks.

  14. Ground deformation from ground-based SAR interferometry

    NASA Astrophysics Data System (ADS)

    Tarchi, Dario; Casagli, Nicola; Fortuny-Guasch, Joaquim; Guerri, Letizia; Antonello, Giuseppe; Leva, Davide

    An in-depth analysis of the last two images acquired by the ground-based interferometric synthetic aperture radar system installed on Stromboli before the 5 April 2003 explosion allowed us to detect the precursory signals of the explosion related to ground deformation. In particular, it was possible to estimate the exact time of the explosion through the time domain analysis of raw data from the radar acquisition. This was interrupted by a blackout that occurred a few seconds after the event. The explosion onset time corresponds to a clear change in the intensity of the backscattered energy, related to the dense volcanic plume emission from the Crater. In addiction, the use of a particular interferometric processing technique for the last two acquisitions, consisting of the selection of synthetic sub-apertures from the main ones and creating with these a sequence of interferograms with a higher temporal resolution, detected precursory deformations starting 2 min before the explosion. These observations indicate the occurrence of an elastic deformation of a centimeter amplitude that affected the volcanic edifice progressively from the Crater down to the Sciara del Fuoco depression.

  15. Better flat-fielding for ground-based UV spectrographs

    NASA Astrophysics Data System (ADS)

    Kerber, Florian; Hanuschik, Reinhard; Moehler, Sabine; Smette, Alain; Smoker, Jonathan; Bourget, Pierre; Dwyer, Peter J.; Rotschädl, Michael

    2014-07-01

    A new technological development, the laser driven light source (LDLS), in which a laser excited plasma emits intense continuum radiation over a wide wavelength range from well below the atmospheric cut-off up to 800 nm, promises to greatly improve our ability to provide high quality flat-fields for astronomical spectrographs. Its particular strength lies in the ground-based ultraviolet (UV). We report on tests conducted with a LDLS using FORS2, UVES, X-Shooter and CRIRES at ESO's Very Large Telescope (VLT) in August 2013. Comparison with standard calibration sources such as halogen and deuterium lamps shows that with the LDLS flat-fields with a better balanced dynamic range and excellent signal to noise ratio can be achieved within short exposure times. This will enable higher quality science at the short wavelength end of existing spectrographs at the VLT. Furthermore the LDLS provides exceptional stability and long lifetime as important operational aspects. Optimised UV spectrographs such as the proposed CUBES (wavelength range 300-400 nm) project will be able to take full advantage of this development removing the long-standing limitation of signal to noise ratios of UV flat-fields.

  16. Ground-based assessment of JAXA mouse habitat cage unit by mouse phenotypic studies.

    PubMed

    Shimbo, Miki; Kudo, Takashi; Hamada, Michito; Jeon, Hyojung; Imamura, Yuki; Asano, Keigo; Okada, Risa; Tsunakawa, Yuki; Mizuno, Seiya; Yagami, Ken-Ichi; Ishikawa, Chihiro; Li, Haiyan; Shiga, Takashi; Ishida, Junji; Hamada, Juri; Murata, Kazuya; Ishimaru, Tomohiro; Hashimoto, Misuzu; Fukamizu, Akiyoshi; Yamane, Mutsumi; Ikawa, Masahito; Morita, Hironobu; Shinohara, Masahiro; Asahara, Hiroshi; Akiyama, Taishin; Akiyama, Nobuko; Sasanuma, Hiroki; Yoshida, Nobuaki; Zhou, Rui; Wang, Ying-Ying; Ito, Taito; Kokubu, Yuko; Noguchi, Taka-Aki K; Ishimine, Hisako; Kurisaki, Akira; Shiba, Dai; Mizuno, Hiroyasu; Shirakawa, Masaki; Ito, Naoki; Takeda, Shin; Takahashi, Satoru

    2016-05-20

    The Japan Aerospace Exploration Agency developed the mouse Habitat Cage Unit (HCU) for installation in the Cell Biology Experiment Facility (CBEF) onboard the Japanese Experimental Module ("Kibo") on the International Space Station. The CBEF provides "space-based controls" by generating artificial gravity in the HCU through a centrifuge, enabling a comparison of the biological consequences of microgravity and artificial gravity of 1 g on mice housed in space. Therefore, prior to the space experiment, a ground-based study to validate the habitability of the HCU is necessary to conduct space experiments using the HCU in the CBEF. Here, we investigated the ground-based effect of a 32-day housing period in the HCU breadboard model on male mice in comparison with the control cage mice. Morphology of skeletal muscle, the thymus, heart, and kidney, and the sperm function showed no critical abnormalities between the control mice and HCU mice. Slight but significant changes caused by the HCU itself were observed, including decreased body weight, increased weights of the thymus and gastrocnemius, reduced thickness of cortical bone of the femur, and several gene expressions from 11 tissues. Results suggest that the HCU provides acceptable conditions for mouse phenotypic analysis using CBEF in space, as long as its characteristic features are considered. Thus, the HCU is a feasible device for future space experiments. PMID:26822934

  17. Functional Allocation for Ground-Based Automated Separation Assurance in NextGen

    NASA Technical Reports Server (NTRS)

    Prevot, Thomas; Mercer, Joey; Martin, Lynne; Homola, Jeffrey; Cabrall, Christopher; Brasil, Connie

    2010-01-01

    As part of an ongoing research effort into functional allocation in a NextGen environment, a controller-in-the-loop study on ground-based automated separation assurance was conducted at NASA Ames' Airspace Operations Laboratory in February 2010. Participants included six FAA front line managers, who are currently certified professional controllers and four recently retired controllers. Traffic scenarios were 15 and 30 minutes long where controllers interacted with advanced technologies for ground-based separation assurance, weather avoidance, and arrival metering. The automation managed the separation by resolving conflicts automatically and involved controllers only by exception, e.g., when the automated resolution would have been outside preset limits. Results from data analyses show that workload was low despite high levels of traffic, Operational Errors did occur but were closely tied to local complexity, and safety acceptability ratings varied with traffic levels. Positive feedback was elicited for the overall concept with discussion on the proper allocation of functions and trust in automation.

  18. Preliminary Design of a Ramjet for Integration with Ground-Based Launch Assist

    NASA Technical Reports Server (NTRS)

    Sayles, Emily L.

    2008-01-01

    This viewgraph presentation reviews the preliminary design of a ramjet for integration with a ground based launch assist. The reasons for the use of ground-based launch assist and the proposed mechanism for a system are reviewed. The use of a Optimal Trajectory by Implicit Simulation (OTIS), to model the flight and comparison with an actual rocket trajectory is given. The OTIS system is reviewed, The benefits of a launch assist system are analyzed concluding that a launch assist can provide supersonic speeds thus allowing ignition of ramjet without an onboard compressor. This means a further reduction in total launch weight. The Ramjet study is reviewed next. This included a review of the ONX simulations, the verification of the ONX results with the use of Holloman Sled experiment data as derived from the Feasibility of Ramjet Engine Test Capability on The Holloman AFB Sled Track. The conclusion was that the ONX system was not sufficient to meet the needs for the modeling required. The GECAT (Graphical Engine Cycle Analysis Tool) is examined. The results of the GECAT simulations was verified with data from Stataltex and D21 flights. The Next steps are: to create a GECAT Model of a launch assist ramjet, to adjust the geometry to produce the desired thrust, and to survey the ramjet's performance over a range of Mach numbers. The assumptions and requirements of a launch assist ramjet are given, and the acceptable flight regimes are reviewed.

  19. Improving Agricultural Water Resources Management Using Ground-based Infrared Thermometry

    NASA Astrophysics Data System (ADS)

    Taghvaeian, S.

    2014-12-01

    Irrigated agriculture is the largest user of freshwater resources in arid/semi-arid parts of the world. Meeting rapidly growing demands in food, feed, fiber, and fuel while minimizing environmental pollution under a changing climate requires significant improvements in agricultural water management and irrigation scheduling. Although recent advances in remote sensing techniques and hydrological modeling has provided valuable information on agricultural water resources and their management, real improvements will only occur if farmers, the decision makers on the ground, are provided with simple, affordable, and practical tools to schedule irrigation events. This presentation reviews efforts in developing methods based on ground-based infrared thermometry and thermography for day-to-day management of irrigation systems. The results of research studies conducted in Colorado and Oklahoma show that ground-based remote sensing methods can be used effectively in quantifying water stress and consequently triggering irrigation events. Crop water use estimates based on stress indices have also showed to be in good agreement with estimates based on other methods (e.g. surface energy balance, root zone soil water balance, etc.). Major challenges toward the adoption of this approach by agricultural producers include the reduced accuracy under cloudy and humid conditions and its inability to forecast irrigation date, which is a critical knowledge since many irrigators need to decide about irrigations a few days in advance.

  20. Detectability and Parameter Estimation of Gravitational Waves from Cosmic String with Ground-Based Detectors

    NASA Astrophysics Data System (ADS)

    Yuzurihara, Hirotaka; Kanda, Nobuyuki

    Cosmic string is one dimensional topological defects which might be formed at the phase transition in the early universe. Gravitational Wave (GW) waveform and its power spectrum from structure in closed cosmic string loop that is called as "cusp" are theoretically predicted. Cosmic string is thought to be described with two characteristic parameters: string tension μ and initial loop size α. We demonstrate numerical simulation for GWs from closed comic string loops to study detectability and parameter decision with ground-based detectors, such as KAGRA, advanced LIGO, advanced Virgo and LIGO-India. We employ characteristic parameters 10 - 13 < Gμ < 10 - 7 and 10 - 16 < α < 10 - 1, assuming uniform distribution of cosmic string in isotropic direction, at time epochs of loop forming and GW emission according to the universe model. We calculate waveform numerically in time domain of each GW from these distributed cosmic strings, and superpose waveforms to generate continuously observational signal on the ground-based GW detectors, including detector responses. We consider data analysis for stochastic background type gravitational wave signatures in the observation.

  1. Towards the development of tamper-resistant, ground-based mobile sensor nodes

    NASA Astrophysics Data System (ADS)

    Mascarenas, David; Stull, Christopher; Farrar, Charles

    2011-11-01

    Mobile sensor nodes hold great potential for collecting field data using fewer resources than human operators would require and potentially requiring fewer sensors than a fixed-position sensor array. It would be very beneficial to allow these mobile sensor nodes to operate unattended with a minimum of human intervention. In order to allow mobile sensor nodes to operate unattended in a field environment, it is imperative that they be capable of identifying and responding to external agents that may attempt to tamper with, damage or steal the mobile sensor nodes, while still performing their data collection mission. Potentially hostile external agents could include animals, other mobile sensor nodes, or humans. This work will focus on developing control policies to help enable a mobile sensor node to identify and avoid capture by a hostile un-mounted human. The work is developed in a simulation environment, and demonstrated using a non-holonomic, ground-based mobile sensor node. This work will be a preliminary step toward ensuring the cyber-physical security of ground-based mobile sensor nodes that operate unattended in potentially unfriendly environments.

  2. Ground-based assessment of JAXA mouse habitat cage unit by mouse phenotypic studies

    PubMed Central

    Shimbo, Miki; Kudo, Takashi; Hamada, Michito; Jeon, Hyojung; Imamura, Yuki; Asano, Keigo; Okada, Risa; Tsunakawa, Yuki; Mizuno, Seiya; Yagami, Ken-ichi; Ishikawa, Chihiro; Li, Haiyan; Shiga, Takashi; Ishida, Junji; Hamada, Juri; Murata, Kazuya; Ishimaru, Tomohiro; Hashimoto, Misuzu; Fukamizu, Akiyoshi; Yamane, Mutsumi; Ikawa, Masahito; Morita, Hironobu; Shinohara, Masahiro; Asahara, Hiroshi; Akiyama, Taishin; Akiyama, Nobuko; Sasanuma, Hiroki; Yoshida, Nobuaki; Zhou, Rui; Wang, Ying-Ying; Ito, Taito; Kokubu, Yuko; Noguchi, Taka-aki K.; Ishimine, Hisako; Kurisaki, Akira; Shiba, Dai; Mizuno, Hiroyasu; Shirakawa, Masaki; Ito, Naoki; Takeda, Shin; Takahashi, Satoru

    2016-01-01

    The Japan Aerospace Exploration Agency developed the mouse Habitat Cage Unit (HCU) for installation in the Cell Biology Experiment Facility (CBEF) onboard the Japanese Experimental Module (“Kibo”) on the International Space Station. The CBEF provides “space-based controls” by generating artificial gravity in the HCU through a centrifuge, enabling a comparison of the biological consequences of microgravity and artificial gravity of 1 g on mice housed in space. Therefore, prior to the space experiment, a ground-based study to validate the habitability of the HCU is necessary to conduct space experiments using the HCU in the CBEF. Here, we investigated the ground-based effect of a 32-day housing period in the HCU breadboard model on male mice in comparison with the control cage mice. Morphology of skeletal muscle, the thymus, heart, and kidney, and the sperm function showed no critical abnormalities between the control mice and HCU mice. Slight but significant changes caused by the HCU itself were observed, including decreased body weight, increased weights of the thymus and gastrocnemius, reduced thickness of cortical bone of the femur, and several gene expressions from 11 tissues. Results suggest that the HCU provides acceptable conditions for mouse phenotypic analysis using CBEF in space, as long as its characteristic features are considered. Thus, the HCU is a feasible device for future space experiments. PMID:26822934

  3. Low frequency gravitational wave detection with ground-based atom interferometer arrays

    NASA Astrophysics Data System (ADS)

    Chaibi, W.; Geiger, R.; Canuel, B.; Bertoldi, A.; Landragin, A.; Bouyer, P.

    2016-01-01

    We propose a new detection strategy for gravitational waves (GWs) below a few hertz based on a correlated array of atom interferometers (AIs). Our proposal allows us to reduce the Newtonian noise (NN), which limits all ground based GW detectors below a few hertz, including previous atom interferometry-based concepts. Using an array of long baseline AI gradiometers yields several estimations of the NN, whose effect can thus be reduced via statistical averaging. Considering the km baseline of current optical detectors, a NN rejection of a factor of 2 could be achieved and tested with existing AI array geometries. Exploiting the correlation properties of the gravity acceleration noise, we show that a tenfold or more NN rejection is possible with a dedicated configuration. Considering a conservative NN model and the current developments in cold atom technology, we show that strain sensitivities below 1 ×10-19/√{Hz } in the 0.3 -3 Hz frequency band can be within reach, with a peak sensitivity of 3 ×10-23/√{Hz } at 2 Hz . Our proposed configuration could extend the observation window of current detectors by a decade and fill the gap between ground-based and space-based instruments.

  4. Ground-based assessment of JAXA mouse habitat cage unit by mouse phenotypic studies.

    PubMed

    Shimbo, Miki; Kudo, Takashi; Hamada, Michito; Jeon, Hyojung; Imamura, Yuki; Asano, Keigo; Okada, Risa; Tsunakawa, Yuki; Mizuno, Seiya; Yagami, Ken-Ichi; Ishikawa, Chihiro; Li, Haiyan; Shiga, Takashi; Ishida, Junji; Hamada, Juri; Murata, Kazuya; Ishimaru, Tomohiro; Hashimoto, Misuzu; Fukamizu, Akiyoshi; Yamane, Mutsumi; Ikawa, Masahito; Morita, Hironobu; Shinohara, Masahiro; Asahara, Hiroshi; Akiyama, Taishin; Akiyama, Nobuko; Sasanuma, Hiroki; Yoshida, Nobuaki; Zhou, Rui; Wang, Ying-Ying; Ito, Taito; Kokubu, Yuko; Noguchi, Taka-Aki K; Ishimine, Hisako; Kurisaki, Akira; Shiba, Dai; Mizuno, Hiroyasu; Shirakawa, Masaki; Ito, Naoki; Takeda, Shin; Takahashi, Satoru

    2016-05-20

    The Japan Aerospace Exploration Agency developed the mouse Habitat Cage Unit (HCU) for installation in the Cell Biology Experiment Facility (CBEF) onboard the Japanese Experimental Module ("Kibo") on the International Space Station. The CBEF provides "space-based controls" by generating artificial gravity in the HCU through a centrifuge, enabling a comparison of the biological consequences of microgravity and artificial gravity of 1 g on mice housed in space. Therefore, prior to the space experiment, a ground-based study to validate the habitability of the HCU is necessary to conduct space experiments using the HCU in the CBEF. Here, we investigated the ground-based effect of a 32-day housing period in the HCU breadboard model on male mice in comparison with the control cage mice. Morphology of skeletal muscle, the thymus, heart, and kidney, and the sperm function showed no critical abnormalities between the control mice and HCU mice. Slight but significant changes caused by the HCU itself were observed, including decreased body weight, increased weights of the thymus and gastrocnemius, reduced thickness of cortical bone of the femur, and several gene expressions from 11 tissues. Results suggest that the HCU provides acceptable conditions for mouse phenotypic analysis using CBEF in space, as long as its characteristic features are considered. Thus, the HCU is a feasible device for future space experiments.

  5. Macrophysical and optical properties of midlatitude cirrus clouds from four ground-based lidars and collocated CALIOP observations

    SciTech Connect

    Dupont, Jean-Charles; Haeffelin, M.; Morille, Y.; Noel, V.; Keckhut, P.; Winker, D.; Comstock, Jennifer M.; Chervet, P.; Roblin, A.

    2010-05-27

    Ground-based lidar and CALIOP datasets gathered over four mid-latitude sites, two US and two French sites, are used to evaluate the consistency of cloud macrophysical and optical property climatologies that can be derived by such datasets. The consistency in average cloud height (both base and top height) between the CALIOP and ground datasets ranges from -0.4km to +0.5km. The cloud geometrical thickness distributions vary significantly between the different datasets, due in part to the original vertical resolutions of the lidar profiles. Average cloud geometrical thicknesses vary from 1.2 to 1.9km, i.e. by more than 50%. Cloud optical thickness distributions in subvisible, semi-transparent and moderate intervals differ by more than 50% between ground and space-based datasets. The cirrus clouds with 2 optical thickness below 0.1 (not included in historical cloud climatologies) represent 30-50% of the non-opaque cirrus class. The differences in average cloud base altitude between ground and CALIOP datasets of 0.0-0.1 km, 0.0-0.2 km and 0.0-0.2 km can be attributed to irregular sampling of seasonal variations in the ground-based data, to day-night differences in detection capabilities by CALIOP, and to the restriction to situations without low-level clouds in ground-based data, respectively. The cloud geometrical thicknesses are not affected by irregular sampling of seasonal variations in the ground-based data, while up to 0.0-0.2 km and 0.1-0.3 km differences can be attributed to day-night differences in detection capabilities by CALIOP, and to the restriction to situations without lowlevel clouds in ground-based data, respectively.

  6. KEPLER AND GROUND-BASED TRANSITS OF THE EXO-NEPTUNE HAT-P-11b

    SciTech Connect

    Deming, Drake; Jackson, Brian; Jennings, Donald E.; Sada, Pedro V.; Peterson, Steven W.; Haase, Flynn; Bays, Kevin; Agol, Eric; Knutson, Heather A.

    2011-10-10

    We analyze 26 archival Kepler transits of the exo-Neptune HAT-P-11b, supplemented by ground-based transits observed in the blue (B band) and near-IR (J band). Both the planet and host star are smaller than previously believed; our analysis yields R{sub p} = 4.31 R{sub +} {+-} 0.06 R{sub +} and R{sub s} = 0.683 R{sub sun} {+-} 0.009 R{sub sun}, both about 3{sigma} smaller than the discovery values. Our ground-based transit data at wavelengths bracketing the Kepler bandpass serve to check the wavelength dependence of stellar limb darkening, and the J-band transit provides a precise and independent constraint on the transit duration. Both the limb darkening and transit duration from our ground-based data are consistent with the new Kepler values for the system parameters. Our smaller radius for the planet implies that its gaseous envelope can be less extensive than previously believed, being very similar to the H-He envelope of GJ 436b and Kepler-4b. HAT-P-11 is an active star, and signatures of star spot crossings are ubiquitous in the Kepler transit data. We develop and apply a methodology to correct the planetary radius for the presence of both crossed and uncrossed star spots. Star spot crossings are concentrated at phases -0.002 and +0.006. This is consistent with inferences from Rossiter-McLaughlin measurements that the planet transits nearly perpendicular to the stellar equator. We identify the dominant phases of star spot crossings with active latitudes on the star, and infer that the stellar rotational pole is inclined at about 12{sup 0} {+-} 5{sup 0} to the plane of the sky. We point out that precise transit measurements over long durations could in principle allow us to construct a stellar Butterfly diagram to probe the cyclic evolution of magnetic activity on this active K-dwarf star.

  7. Distribution of Io's Volcanic Thermal Emission From Galileo and Ground-Based Data

    NASA Astrophysics Data System (ADS)

    Veeder, G. J.; Davies, A. G.; Matson, D.; Johnson, T. V.; Williams, D. A.; Radebaugh, J.

    2011-12-01

    Detections of Io's hot spots and identification of volcanic features have been catalogued by various workers [e.g., 1-4]. However, to understand the role played by volcanism in global heat transport, thermal emission from Io's volcanoes has to be quantified, locally, regionally and globally. Only then can robust estimates be made of volcanic advection, which may reveal internal heating patterns controlled by the evolving tidal resonance between Io, Europa and Ganymede. We have completed an analysis of all suitable spacecraft data and, using additional ground-based data, have quantified the thermal emission from all of Io's volcanoes during the Galileo epoch down to the limit of detection [5-7]. Galileo identified many dark features on Io that did not exhibit obvious anomalous thermal emission, yet their low albedo suggested that these features were at least warm (cool, high albedo sulphurous deposits had not formed on them). We used dark areas identified from the recently-published Io Global Map [3] and a knowledge of the detection limit of the Galileo NIMS instrument to quantify the thermal emission from these areas. In all, our analysis includes 272 individual thermal sources yielding ~60 TW. Our "snapshot" of global volcanic activity shows that Io's paterae yield ~80% of this amount, with a preponderance of thermal emission emanating from the northern hemisphere. This is strongly biased by Loki Patera and, to a lesser extent, by recent outburst locations. Of the remaining identified hot spot thermal emission, ~15% comes from active or recent lava flow fields, and the remaining 5% comes from massive outburst eruptions (some in paterae) and very small hot spots. The energy accounted for makes up ~60% of Io's total thermal emission of ~100 TW [8]. It is possible that a multitude of very small hot spots beneath instrument detection limits, and/or cooler, secondary volcanic processes involving sulphurous compounds may be responsible for the unaccounted heat flow

  8. The EMT-activator ZEB1 induces bone metastasis associated genes including BMP-inhibitors

    PubMed Central

    Mock, Kerstin; Preca, Bogdan-Tiberius; Brummer, Tilman; Brabletz, Simone; Stemmler, Marc P.; Brabletz, Thomas

    2015-01-01

    Tumor cell invasion, dissemination and metastasis is triggered by an aberrant activation of epithelial-to-mesenchymal transition (EMT), often mediated by the transcription factor ZEB1. Disseminating tumor cells must acquire specific features that allow them to colonize at different organ sites. Here we identify a set of genes that is highly expressed in breast cancer bone metastasis and activated by ZEB1. This gene set includes various secreted factors, e.g. the BMP-inhibitor FST, that are described to reorganize the bone microenvironment. By inactivating BMP-signaling, BMP-inhibitors are well-known to induce osteolysis in development and disease. We here demonstrate that the expression of ZEB1 and BMP-inhibitors is correlated with bone metastasis, but not with brain or lung metastasis of breast cancer patients. In addition, we show that this correlated expression pattern is causally linked, as ZEB1 induces the expression of the BMP-inhibitors NOG, FST and CHRDL1 both by directly increasing their gene transcription, as well as by indirectly suppressing their reduction via miR-200 family members. Consequently, ZEB1 stimulates BMP-inhibitor mediated osteoclast differentiation. These findings suggest that ZEB1 is not only driving EMT, but also contributes to the formation of osteolytic bone metastases in breast cancer. PMID:25973542

  9. Evolution of ground-based gamma-ray astronomy from the early days to the Cherenkov Telescope Arrays

    NASA Astrophysics Data System (ADS)

    Hillas, A. M.

    2013-03-01

    Most of what we know of cosmic gamma rays has come from spacecraft, but at energies above tens of GeV it has become possible to make observations with ground-based detectors of enormously greater collecting area. In recent years one such detector type, the cluster of imaging air Cherenkov telescopes, has reached a very productive state, whilst several alternative approaches have been explored, including converted solar power collectors and novel high-altitude particle shower detectors which promised to extend the energy range covered. Key examples of development from 1952 to 2011 are followed, noting the problems and discoveries that stimulated the current work, explaining the logic of the alternative approaches that were taken. The merits of the current major Cherenkov observatories and of other viable detectors are examined and compared, with examples of the astrophysical information they are beginning to provide. The detectors are still evolving, as we still do not understand the processes onto which the gamma rays provide a window. These include the acceleration of Galactic cosmic rays (in particular, the wide-band spectra of radiation from some individual supernova remnants are still hard to interpret), the highly relativistic and variable jets from active galactic nuclei, and aspects of the electrodynamics of pulsars. Larger groups of Cherenkov telescopes still offer the possibility of an increase in power of the technique for resolvable Galactic sources especially.

  10. Spatiotemporal Path-Matching for Comparisons Between Ground- Based and Satellite Lidar Measurements

    NASA Technical Reports Server (NTRS)

    Berkoff, Timothy A.; Valencia, Sandra; Welton, Ellsworth J.; Spinhirne, James D.

    2005-01-01

    The spatiotemporal sampling differences between ground-based and satellite lidar data can contribute to significant errors for direct measurement comparisons. Improvement in sample correspondence is examined by the use of radiosonde wind velocity to vary the time average in ground-based lidar data to spatially match coincident satellite lidar measurements. Results are shown for the 26 February 2004 GLAS/ICESat overflight of a ground-based lidar stationed at NASA GSFC. Statistical analysis indicates that improvement in signal correlation is expected under certain conditions, even when a ground-based observation is mismatched in directional orientation to the satellite track.

  11. Guide for inservice inspection of ground-based pressure vessels and systems

    NASA Technical Reports Server (NTRS)

    1976-01-01

    This guide includes recommendations for inservice inspection and recertification of ground based, unfired pressure vessels and all pressurized systems including those served by fired pressure vessels hereinafter referred to as pressure vessels, systems and components of systems. It covers the vast array of pound based industrial and special purpose pressurized components and systems used at NASA field installations for research and development and those utility systems and components that require more than routine maintenance to insure continued structural integrity for their useful life. Through surveillance and correction of inservice deterioration, NASA will maintain a safe working environment for their own and contractor personnel, safety for the public sector and protection against loss of capital investment.

  12. Ozone profiles above Kiruna from two ground-based radiometers

    NASA Astrophysics Data System (ADS)

    Ryan, Niall J.; Walker, Kaley A.; Raffalski, Uwe; Kivi, Rigel; Gross, Jochen; Manney, Gloria L.

    2016-09-01

    This paper presents new atmospheric ozone concentration profiles retrieved from measurements made with two ground-based millimetre-wave radiometers in Kiruna, Sweden. The instruments are the Kiruna Microwave Radiometer (KIMRA) and the Millimeter wave Radiometer 2 (MIRA 2). The ozone concentration profiles are retrieved using an optimal estimation inversion technique, and they cover an altitude range of ˜ 16-54 km, with an altitude resolution of, at best, 8 km. The KIMRA and MIRA 2 measurements are compared to each other, to measurements from balloon-borne ozonesonde measurements at Sodankylä, Finland, and to measurements made by the Microwave Limb Sounder (MLS) aboard the Aura satellite. KIMRA has a correlation of 0.82, but shows a low bias, with respect to the ozonesonde data, and MIRA 2 shows a smaller magnitude low bias and a 0.98 correlation coefficient. Both radiometers are in general agreement with each other and with MLS data, showing high correlation coefficients, but there are differences between measurements that are not explained by random errors. An oscillatory bias with a peak of approximately ±1 ppmv is identified in the KIMRA ozone profiles over an altitude range of ˜ 18-35 km, and is believed to be due to baseline wave features that are present in the spectra. A time series analysis of KIMRA ozone for winters 2008-2013 shows the existence of a local wintertime minimum in the ozone profile above Kiruna. The measurements have been ongoing at Kiruna since 2002 and late 2012 for KIMRA and MIRA 2, respectively.

  13. Project management for complex ground-based instruments: MEGARA plan

    NASA Astrophysics Data System (ADS)

    García-Vargas, María. Luisa; Pérez-Calpena, Ana; Gil de Paz, Armando; Gallego, Jesús; Carrasco, Esperanza; Cedazo, Raquel; Iglesias, Jorge

    2014-08-01

    The project management of complex instruments for ground-based large telescopes is a challenge itself. A good management is a clue for project success in terms of performance, schedule and budget. Being on time has become a strict requirement for two reasons: to assure the arrival at the telescope due to the pressure on demanding new instrumentation for this first world-class telescopes and to not fall in over-costs. The budget and cash-flow is not always the expected one and has to be properly handled from different administrative departments at the funding centers worldwide distributed. The complexity of the organizations, the technological and scientific return to the Consortium partners and the participation in the project of all kind of professional centers working in astronomical instrumentation: universities, research centers, small and large private companies, workshops and providers, etc. make the project management strategy, and the tools and procedures tuned to the project needs, crucial for success. MEGARA (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) is a facility instrument of the 10.4m GTC (La Palma, Spain) working at optical wavelengths that provides both Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) capabilities at resolutions in the range R=6,000-20,000. The project is an initiative led by Universidad Complutense de Madrid (Spain) in collaboration with INAOE (Mexico), IAA-CSIC (Spain) and Universidad Politécnica de Madrid (Spain). MEGARA is being developed under contract with GRANTECAN.

  14. Ground-based Measurement Of Saharan Dust In Marine Environment

    NASA Astrophysics Data System (ADS)

    Jeong, M. J.; Ji, Q.; Tsay, S.; Hsu, C.; Hansell, R. A.; Augustine, D.

    2007-12-01

    An extensive field experiment, named NASA African Monsoon Multidisciplinary Analyses (NAMMA) was conducted during August-September of 2006 to investigate the genesis and development of hurricanes. Two ground-based mobile laboratories, Surface-sensing Measurements for Atmospheric Radiative Transfer (SMART) and Chemical, Optical, Microphysical Measurements of In-situ Troposphere (COMMIT), were deployed at Sal Island, Cape Verde to continuously monitor the structure and composition of the atmosphere in the major path of the Saharan Air Layer and the African Easterly Waves. A Micro-Pulse Lidar in SMART, which measures the vertical profiles of backscatter from the atmospheric particulates continuously, caught several episodes of Saharan dust layers reached the surface site. Simultaneously, physical and optical properties of aerosols (e.g., mixture of the Saharan dust and maritime aerosols) were captured by several instruments in COMMIT. In this study, we propose a novel method to separate dust properties from those of marine background aerosols by utilizing the synergy of a suite of in-situ measurements. Derived parameters are mass scattering coefficients and single scattering albedo (SSA) for dust near the surface (~10m). As a crosscheck, the SSA based on the surface measurements is compared with the result of Deep Blue satellite-based aerosol retrievals, which is now incorporated in the operational MODIS aerosol product. The presented preliminary results will be useful in studying the properties of Saharan dust originated from various source regions, which, in turns, can be used as inputs to aerosol transport models to help better understand the interactions between aerosol and cloud water cycle.

  15. Ground-based observations of the Io plasma torus

    NASA Astrophysics Data System (ADS)

    Thomas, N.

    A series of ground-based 1-D spatially resolved, high resolution spectra (in SII, SIII, and OII) of the Io plasma torus were acquired in October 1999, around the time of the Galileo I24 passage through the IPT. In a previous paper (Thomas et al., JGR, 106, 26277, 2001), we have presented the initial results from these observations. In this presentation, we will describe recent more detailed analysis which seems to be lending further insight into the structure of the IPT. In particular, we have used an "onion-peeling" technique to remove line of sight effects from the observations. The resulting profiles, show the so-called ribbon region (5.7 RJ) being clearly separated from the cold torus (5.3 RJ) by a region of lower SII emission. SIII emission is now shown to be almost completely absent in the cold torus. The ratio of these two species is seen to rise systematically and almost linearly with jovicentric distance from the cold torus through to the warm torus (beyond 6.0 RJ). Models can be used to interpret this behaviour in terms of changing electron temperature with distance. We compare our results with the only other measurement of this property which was based on Voyager 1 PLS observations. We further show that the peak of OII emission is not centred at the, what we now call, the sulphur ribbon. We attempt to derive the relative composition of the three major species in the torus as a function of jovicentric distance using our data.

  16. Ground-Based Remote Retrievals of Cumulus Entrainment Rates

    SciTech Connect

    Wagner, Timothy J.; Turner, David D.; Berg, Larry K.; Krueger, Steven K.

    2013-07-26

    While fractional entrainment rates for cumulus clouds have typically been derived from airborne observations, this limits the size and scope of available data sets. To increase the number of continental cumulus entrainment rate observations available for study, an algorithm for retrieving them from ground-based remote sensing observations has been developed. This algorithm, called the Entrainment Rate In Cumulus Algorithm (ERICA), uses the suite of instruments at the Southern Great Plains (SGP) site of the United States Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility as inputs into a Gauss-Newton optimal estimation scheme, in which an assumed guess of the entrainment rate is iteratively adjusted through intercomparison of modeled liquid water path and cloud droplet effective radius to their observed counterparts. The forward model in this algorithm is the Explicit Mixing Parcel Model (EMPM), a cloud parcel model that treats entrainment as a series of discrete entrainment events. A quantified value for measurement uncertainty is also returned as part of the retrieval. Sensitivity testing and information content analysis demonstrate the robust nature of this method for retrieving accurate observations of the entrainment rate without the drawbacks of airborne sampling. Results from a test of ERICA on three months of shallow cumulus cloud events show significant variability of the entrainment rate of clouds in a single day and from one day to the next. The mean value of 1.06 km-¹ for the entrainment rate in this dataset corresponds well with prior observations and simulations of the entrainment rate in cumulus clouds.

  17. Jovian thundercloud research with ground-based telescope and spacecraft

    NASA Astrophysics Data System (ADS)

    Takahashi, Yukihiro; Nakajima, Kensuke; Takeuchi, Satoru; Sugiyama, Ko-Ichiro; Sato, Mitsuteru; Fukuhara, Tetsuya; Sato, Soga; Yair, Yoav; Aplin, Karen; Fischer, Georg

    2010-05-01

    The latest observational and theoretical studies suggest that thunderstorms, i.e., strong moist convective clouds in Jupiter's atmosphere are very important not only as an essential ingredient of meteorology of Jupiter, which determines the large scale structures such as belt/zone and big ovals, but also as a potentially very useful tool for probing the water abundance of the deep atmosphere, which is crucial to constrain the behavior of volatiles in early solar system. Here we suggest a very simple high-speed imaging unit onboard Jovian orbiter, Optical Lightning Detector, OLD, optimized for detecting optical emissions from lightning discharge in Jupiter. OLD consists of radiation-tolerant CMOS sensors and two H Balmer Alpha line (656.3nm) filters. In normal sampling mode the frame intervals is 29ms with a full frame format of 512x512 pixels and in high-speed sampling mode the interval could be reduced down to 0.1ms by concentrating a limited area of 30x30 pixels. Weight, size and power consumption are about 1kg, 16x7x5.5 cm (sensor) and 16x12x4 cm (circuit), and 4W, respectively, though they can be reduced according to the spacecraft resources. Also we plan to investigate the optical flashes using a ground-based middle-sized telescope, which will be built by Hokkaido University, with narrow-band high speed imaging unit. Observational strategy with such optical lightning detectors and spectral imagers, which enable us to estimate the horizontal motion and altitude of clouds, will be introduced.

  18. Coordinated Ground-Based Observations and the New Horizons Fly-by of Pluto

    NASA Astrophysics Data System (ADS)

    Young, Eliot; Young, Leslie; Parker, Joel; Binzel, Richard

    2015-04-01

    The New Horizons (NH) spacecraft is scheduled to make its closest approach to Pluto on July 14, 2015. NH carries seven scientific instruments, including separate UV and Visible-IR spectrographs, a long-focal-length imager, two plasma-sensing instruments and a dust counter. There are three arenas in particular in which ground-based observations should augment the NH instrument suite in synergistic ways: IR spectra at wavelengths longer than 2.5 µm (i.e., longer than the NH Ralph spectrograph), stellar occultation observations near the time of the fly-by, and thermal surface maps and atmospheric CO abundances based on ALMA observations - we discuss the first two of these. IR spectra in the 3 - 5 µm range cover the CH4 absorption band near 3.3 µm. This band can be an important constraint on the state and areal extent of nitrogen frost on Pluto's surface. If this band depth is close to zero (as was observed by Olkin et al. 2007), it limits the area of nitrogen frost, which is bright at that wavelength. Combined with the NH observations of nitrogen frost at 2.15 µm, the ground-based spectra will determine how much nitrogen frost is diluted with methane, which is a basic constraint on the seasonal cycle of sublimation and condensation that takes place on Pluto (and similar objects like Triton and Eris). There is a fortuitous stellar occultation by Pluto on 29-JUN-2015, only two weeks before the NH closest approach. The occulted star will be the brightest ever observed in a Pluto event, about 2 magnitudes brighter than Pluto itself. The track of the event is predicted to cover parts of Australia and New Zealand. Thanks to HST and ground based campaigns to find a TNO target reachable by NH, the position of the shadow path will be known at the +/-100 km level, allowing SOFIA and mobile ground-based observers to reliably cover the central flash region. Ground-based & SOFIA observations in visible and IR wavelengths will characterize the haze opacity and vertical

  19. Overview and Initial Results from the DEEPWAVE Airborne and Ground-Based Measurement Program

    NASA Astrophysics Data System (ADS)

    Fritts, D. C.

    2015-12-01

    The deep-propagating gravity wave experiment (DEEPWAVE) was performed on and over New Zealand, the Tasman Sea, and the Southern Ocean with core airborne measurements extending from 5 June to 21 July 2014 and supporting ground-based measurements spanning a longer interval. The NSF/NCAR GV employed standard flight-level measurements and new airborne lidar and imaging measurements of gravity waves (GWs) from sources at lower altitudes throughout the stratosphere and into the mesosphere and lower thermosphere (MLT). The new GV lidars included a Rayleigh lidar measuring atmospheric density and temperature from ~20-60 km and a sodium resonance lidar measuring sodium density and temperature at ~75-105 km. An airborne Advanced Mesosphere Temperature Mapper (AMTM) and two IR "wing" cameras imaged the OH airglow temperature and/or intensity fields extending ~900 km across the GV flight track. The DLR Falcon was equipped with its standard flight-level instruments and an aerosol Doppler lidar measuring radial winds below the Falcon. DEEPWAVE also included extensive ground-based measurements in New Zealand, Tasmania, and Southern Ocean Islands. DEEPWAVE performed 26 GV flights and 13 Falcon flights, and ground-based measurements occurred whether or not the aircraft were flying. Collectively, many diverse cases of GW forcing, propagation, refraction, and dissipation spanning altitudes of 0-100 km were observed. Examples include strong mountain wave (MW) forcing and breaking in the lower and middle stratosphere, weak MW forcing yielding MW penetration into the MLT having very large amplitudes and momentum fluxes, MW scales at higher altitudes ranging from ~10-250 km, large-scale trailing waves from orography refracting into the polar vortex and extending to high altitudes, GW generation by deep convection, large-scale GWs arising from jet stream sources, and strong MWs in the MLT arising from strong surface flow over a small island. DEEPWAVE yielded a number of surprises, among

  20. Ground-based simulation of telepresence for materials science experiments. [remote viewing and control of processes aboard Space Station

    NASA Technical Reports Server (NTRS)

    Johnston, James C.; Rosenthal, Bruce N.; Bonner, Mary JO; Hahn, Richard C.; Herbach, Bruce

    1989-01-01

    A series of ground-based telepresence experiments have been performed to determine the minimum video frame rate and resolution required for the successive performance of materials science experiments in space. The approach used is to simulate transmission between earth and space station with transmission between laboratories on earth. The experiments include isothermal dendrite growth, physical vapor transport, and glass melting. Modifications of existing apparatus, software developed, and the establishment of an inhouse network are reviewed.

  1. Be BOLD: Encouraging Girls to Include Unstructured Bouts of Physical Activity into Daily Routines

    ERIC Educational Resources Information Center

    Hill, Kory; Williams, Gwynne M.

    2014-01-01

    Adolescent girls are less active than their male counterparts and physical activity levels tend to decline as one ages. One of the goals of concerned physical educators is to promote a physically active lifestyle and to teach skills and promote behaviors that will allow students to be active both in and out of school. This article presents a…

  2. Evaluation of satellite soil moisture products over Norway using ground-based observations

    NASA Astrophysics Data System (ADS)

    Griesfeller, A.; Lahoz, W. A.; Jeu, R. A. M. de; Dorigo, W.; Haugen, L. E.; Svendby, T. M.; Wagner, W.

    2016-03-01

    In this study we evaluate satellite soil moisture products from the advanced SCATterometer (ASCAT) and the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) over Norway using ground-based observations from the Norwegian water resources and energy directorate. The ASCAT data are produced using the change detection approach of Wagner et al. (1999), and the AMSR-E data are produced using the VUA-NASA algorithm (Owe et al., 2001, 2008). Although satellite and ground-based soil moisture data for Norway have been available for several years, hitherto, such an evaluation has not been performed. This is partly because satellite measurements of soil moisture over Norway are complicated owing to the presence of snow, ice, water bodies, orography, rocks, and a very high coastline-to-area ratio. This work extends the European areas over which satellite soil moisture is validated to the Nordic regions. Owing to the challenging conditions for soil moisture measurements over Norway, the work described in this paper provides a stringent test of the capabilities of satellite sensors to measure soil moisture remotely. We show that the satellite and in situ data agree well, with averaged correlation (R) values of 0.72 and 0.68 for ASCAT descending and ascending data vs in situ data, and 0.64 and 0.52 for AMSR-E descending and ascending data vs in situ data for the summer/autumn season (1 June-15 October), over a period of 3 years (2009-2011). This level of agreement indicates that, generally, the ASCAT and AMSR-E soil moisture products over Norway have high quality, and would be useful for various applications, including land surface monitoring, weather forecasting, hydrological modelling, and climate studies. The increasing emphasis on coupled approaches to study the earth system, including the interactions between the land surface and the atmosphere, will benefit from the availability of validated and improved soil moisture satellite datasets, including those

  3. Description of the Large Gap Magnetic Suspension System (LGMSS) ground-based experiment

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J.

    1991-01-01

    A description of the Large Gap Magnetic Suspension System (LGMSS) ground-based experiment is presented. The LGMSS provides five degrees of freedom control of a cylindrical suspended element which is levitated above a floor-mounted array of air core electromagnets. The uncontrolled degree of freedom is rotation about the long axis of the cylinder (roll). Levitation and control forces are produced on a permanent magnet core which is embedded in the cylinder. The cylinder also contains light emitting diodes (LEDs), assorted electrons, and a power supply. The LEDs provide active targets for an optical position measurement system which is being developed in-house at the Langley Research Center. The optical position measurement system will provide six degrees of freedom position information for the LGMSS control system.

  4. Active control of environmental noise, VIII: increasing the response to primary source changes including unpredictable noise

    NASA Astrophysics Data System (ADS)

    Wright, S. E.; Atmoko, H.; Vuksanovic, B.

    2004-07-01

    Conventional adaptive cancellation systems using traditional transverse finite impulse response (FIR) filters, together with least mean square (LMS) adaptive algorithms, well known in active noise control, are slow to adapt to primary source changes. This makes them inappropriate for cancelling rapidly changing noise, including unpredictable noise such as speech and music. Secondly, the cancelling structures require considerable computational processing effort to adapt to primary source and plant changes, particularly for multi-channel systems. This paper describes methods to increase the adaptive speed to primary source changes in large enclosed spaces and outdoor environments. A method is described that increases the response to time varying periodic noise using traditional transverse FIR filters. Here a multi-passband filter, with individual variable adaptive step sizes for each passband is automatically adjusted according to the signal level in each band. This creates a similar adaptive response for all frequencies within the total pass-band, irrespective of amplitude, minimizing the signal distortion and increasing the combined adaptive speed. Unfortunately, there is a limit to the adaptive speed using the above method as classical transverse FIR filters have a finite adaptive speed given by the stability band zero bandwidth. For rapidly changing periodic noise and unpredictable non-stationary noise, a rapid to instantaneous response is required. In this case the on-line adaptive FIR filters are dispensed with and replaced by a time domain solution that gives virtually instantaneous cancellation response (infinite adaptive speed) to primary source changes, and is computationally efficient.

  5. NVO, surveys and archiving ground-based data

    NASA Astrophysics Data System (ADS)

    Huchra, John P.

    2002-12-01

    The era of extremely large, public databases in astronomy is upon us. Such databases will open (are opening!) the field to new research and new researchers. However it is important to be sure the resources are available to properly archive groundbased astronomical data, and include the necessary quality checks and calibrations. An NVO without a proper archive will have limited usefulness. This also implies that with limited resources, not all data can or should be archived. NASA already has a very good handle on US space-based astronomical data. Agencies and organizations that operate astronomical facilities, particularly groundbased observatories, need to plan and budget for these activities now. We should not underestimate the effort required to produce high quality data products that will be useful for the broader community.

  6. Ground Based Investigation of Electrostatic Accelerometer in HUST

    NASA Astrophysics Data System (ADS)

    Bai, Y.; Zhou, Z.

    2013-12-01

    High-precision electrostatic accelerometers with six degrees of freedom (DOF) acceleration measurement were successfully used in CHAMP, GRACE and GOCE missions which to measure the Earth's gravity field. In our group, space inertial sensor based on the capacitance transducer and electrostatic control technique has been investigated for test of equivalence principle (TEPO), searching non-Newtonian force in micrometer range, and satellite Earth's field recovery. The significant techniques of capacitive position sensor with the noise level at 2×10-7pF/Hz1/2 and the μV/Hz1/2 level electrostatic actuator are carried out and all the six servo loop controls by using a discrete PID algorithm are realized in a FPGA device. For testing on ground, in order to compensate one g earth's gravity, the fiber torsion pendulum facility is adopt to measure the parameters of the electrostatic controlled inertial sensor such as the resolution, and the electrostatic stiffness, the cross couple between different DOFs. A short distance and a simple double capsule equipment the valid duration about 0.5 second is set up in our lab for the free fall tests of the engineering model which can directly verify the function of six DOF control. Meanwhile, high voltage suspension method is also realized and preliminary results show that the horizontal axis of acceleration noise is about 10-8m/s2/Hz1/2 level which limited mainly by the seismic noise. Reference: [1] Fen Gao, Ze-Bing Zhou, Jun Luo, Feasibility for Testing the Equivalence Principle with Optical Readout in Space, Chin. Phys. Lett. 28(8) (2011) 080401. [2] Z. Zhu, Z. B. Zhou, L. Cai, Y. Z. Bai, J. Luo, Electrostatic gravity gradiometer design for the advanced GOCE mission, Adv. Sp. Res. 51 (2013) 2269-2276. [3] Z B Zhou, L Liu, H B Tu, Y Z Bai, J Luo, Seismic noise limit for ground-based performance measurements of an inertial sensor using a torsion balance, Class. Quantum Grav. 27 (2010) 175012. [4] H B Tu, Y Z Bai, Z B Zhou, L Liu, L

  7. Comparison of On-Orbit and Ground Based Hollow Cathode Operation

    NASA Technical Reports Server (NTRS)

    Burke, Tom (Technical Monitor); Carpenter, Christian

    2003-01-01

    The Plasma Contactor Unit (PCU) was developed by the Rocketdyne division of Boeing to control charging of the International Space Station (ISS). Each PCU contains a Hollow Cathode Assembly (HCA), which emits the charge control electrons. The HCAs were designed and fabricated at NASA's Glenn Research Center (GRC). GRC's HCA development program included manufacture of engineering, qualification, and flight model HCAs as well as wear tests and qualification tests. GRC is currently tracking the on-orbit data for the flight HCAs. This data will be discussed with comparison to operating parameters verified by ground based HCA tests. The flight HCAs continue to operate flawlessly. The first unit has accumulated more than 3650 hours of on-orbit operation and the second unit has accumulated over 5550 hours.

  8. Autonomous landing of a helicopter UAV with a ground-based multisensory fusion system

    NASA Astrophysics Data System (ADS)

    Zhou, Dianle; Zhong, Zhiwei; Zhang, Daibing; Shen, Lincheng; Yan, Chengping

    2015-02-01

    In this study, this paper focus on the vision-based autonomous helicopter unmanned aerial vehicle (UAV) landing problems. This paper proposed a multisensory fusion to autonomous landing of an UAV. The systems include an infrared camera, an Ultra-wideband radar that measure distance between UAV and Ground-Based system, an PAN-Tilt Unit (PTU). In order to identify all weather UAV targets, we use infrared cameras. To reduce the complexity of the stereovision or one-cameral calculating the target of three-dimensional coordinates, using the ultra-wideband radar distance module provides visual depth information, real-time Image-PTU tracking UAV and calculate the UAV threedimensional coordinates. Compared to the DGPS, the test results show that the paper is effectiveness and robustness.

  9. Ground-based lidar beach topography of Fire Island, New York, April 2013

    USGS Publications Warehouse

    Brenner, Owen T.; Hapke, Cheryl J.; Spore, Nicholas J.; Brodie, Katherine L.; McNinch, Jesse E.

    2015-01-01

    The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center in Florida and the U.S. Army Corps of Engineers Field Research Facility in Duck, North Carolina, collaborated to gather alongshore ground-based lidar beach elevation data at Fire Island, New York. This high-resolution elevation dataset was collected on April 10, 2013, to characterize beach topography following substantial erosion that occurred during Hurricane Sandy, which made landfall on October 29, 2012, and multiple, strong winter storms. The ongoing beach monitoring is part of the Hurricane Sandy Supplemental Project GS2-2B. This USGS data series includes the resulting processed elevation point data (xyz) and an interpolated digital elevation model (DEM).

  10. Calibration of AIS Data Using Ground-based Spectral Reflectance Measurements

    NASA Technical Reports Server (NTRS)

    Conel, J. E.

    1985-01-01

    Present methods of correcting airborne imaging spectrometer (AIS) data for instrumental and atmospheric effects include the flat- or curved-field correction and a deviation-from-the-average adjustment performed on a line-by-line basis throughout the image. Both methods eliminate the atmospheric absorptions, but remove the possibility of studying the atmosphere for its own sake, or of using the atmospheric information present as a possible basis for theoretical modeling. The method discussed here relies on use of ground-based measurements of the surface spectral reflectance in comparison with scanner data to fix in a least-squares sense parameters in a simplified model of the atmosphere on a wavelength-by-wavelength basis. The model parameters (for optically thin conditions) are interpretable in terms of optical depth and scattering phase function, and thus, in principle, provide an approximate description of the atmosphere as a homogeneous body intervening between the sensor and the ground.

  11. Quantifying greenhouse gas emissions from coal fires using airborne and ground-based methods

    USGS Publications Warehouse

    Engle, M.A.; Radke, L.F.; Heffern, E.L.; O'Keefe, J. M. K.; Smeltzer, C.D.; Hower, J.C.; Hower, J.M.; Prakash, A.; Kolker, A.; Eatwell, R.J.; ter, Schure A.; Queen, G.; Aggen, K.L.; Stracher, G.B.; Henke, K.R.; Olea, R.A.; Roman-Colon, Y.

    2011-01-01

    Coal fires occur in all coal-bearing regions of the world and number, conservatively, in the thousands. These fires emit a variety of compounds including greenhouse gases. However, the magnitude of the contribution of combustion gases from coal fires to the environment is highly uncertain, because adequate data and methods for assessing emissions are lacking. This study demonstrates the ability to estimate CO2 and CH4 emissions for the Welch Ranch coal fire, Powder River Basin, Wyoming, USA, using two independent methods: (a) heat flux calculated from aerial thermal infrared imaging (3.7-4.4td-1 of CO2 equivalent emissions) and (b) direct, ground-based measurements (7.3-9.5td-1 of CO2 equivalent emissions). Both approaches offer the potential for conducting inventories of coal fires to assess their gas emissions and to evaluate and prioritize fires for mitigation. ?? 2011.

  12. Aerosol Absorption in the Atmosphere: Perspectives from Global Model, Ground-Based Measurements, and Field Observations

    NASA Technical Reports Server (NTRS)

    Chin, Mian; Holben, Brent; Anderson, Tad; Quinn, Patricia; Duncan, Bryan; Ginoux, Paul

    2003-01-01

    Aerosol absorption in the atmosphere poses a major uncertainty in assessing the aerosol climate effects. This uncertainty arises from the poorly quantified aerosol sources, especially black carbon emissions, and our limited knowledge of aerosol mixing state and optical properties. Here we use a global model GOCART to simulate atmospheric aerosols, including sulfate, black carbon, organic carbon, dust, and sea salt. We compare the model calculated total aerosol optical thickness, extinction, and absorption with those quantities from the ground-based sun photometer measurements from AERONET at several different wavelengths and the field observations from ACE-Asia. We will examine what are the most sensitive factors in determining the aerosol absorption, and the consequences of assessing the aerosol radiative forcing and atmospheric heating associated with those factors.

  13. Aerosol Absorption in the Atmosphere: Perspectives from Global Model, Ground-Based Measurements, and Field Observations

    NASA Technical Reports Server (NTRS)

    Chin, Mian; Dubovik, Oleg; Holben, Brent; Torres, Omar; Anderson, Tad; Quinn, Patricia; Ginoux, Paul

    2004-01-01

    Aerosol absorption in the atmosphere poses a major uncertainty in assessing the aerosol climate effects. This uncertainty arises from the poorly quantified aerosol sources, especially black carbon emissions, and our limited knowledge of aerosol mixing state and optical properties. Here we use a global model GOCART to simulate atmospheric aerosols, including sulfate, black carbon, organic carbon, dust, and sea salt. We compare the model calculated total aerosol optical thickness, extinction, and absorption with those quantities from the ground-based sun photometer measurements from AERONET, satellite retrievals from the TOMS instrument, and field observations from ACE-Asia. We will examine the most sensitive factors in determining the aerosol absorption. and the consequences of assessing the aerosol radiative forcing and atmospheric heating associated with those factors.

  14. Aerosol Absorption in the Atmosphere: Perspectives from Global Model, Ground-Based Measurements, and Field Observations

    NASA Technical Reports Server (NTRS)

    Chin, Main; Dubovik, Oleg; Holben, Brent; Anderson, Tad; Quinn, Patricia; Duncan, Bryan; Ginoux, Paul

    2004-01-01

    Aerosol absorption in the atmosphere poses a major uncertainty in assessing the aerosol climate effects. This uncertainty arises from the poorly quantified aerosol sources, especially black carbon emissions, and our limited knowledge of aerosol mixing state and optical properties. Here we use a global model GOCART to simulate atmospheric aerosols, including sulfate, black carbon, organic carbon, dust, and sea salt. We compare the model calculated total aerosol optical thickness, extinction, and absorption with those quantities from the ground-based sun photometer measurements from AERONET at several different wavelengths and the field observations from ACE-Asia. We will examine the most sensitive factors in determining the aerosol absorption, and the consequences of assessing the aerosol radiative forcing and atmospheric heating associated with those factors.

  15. Instruments, Detectors and the Future of Astronomy with Large Ground Based Telescopes

    NASA Astrophysics Data System (ADS)

    Simons, Douglas A.; Amico, Paola; Baade, Dietrich; Barden, Sam; Campbell, Randall; Finger, Gert; Gilmore, Kirk; Gredel, Roland; Hickson, Paul; Howell, Steve; Hubin, Norbert; Kaufer, Andreas; Kohley, Ralf; MacQueen, Philip; Markelov, Sergej; Merrill, Mike; Miyazaki, Satoshi; Nakaya, Hidehiko; O'Donoghue, Darragh; Oliva, Tino; Richichi, Andrea; Salmon, Derrick; Schmidt, Ricardo; Su, Hongjun; Tulloch, Simon; García Vargas, Maria Luisa; Wagner, R. Mark; Wiecha, Olivier; Ye, Binxun

    2005-01-01

    Results of a survey of instrumentation and detector systems, either currently deployed or planned for use at telescopes larger than 3.5 m, in ground based observatories world-wide, are presented. This survey revealed a number of instrumentation design trends at optical, near, and mid-infrared wavelengths. Some of the most prominent trends include the development of vastly larger optical detector systems (> 109 pixels) than anything built to date, and the frequent use of mosaics of near-infrared detectors - something that was quite rare only a decade ago in astronomy. Some future science applications for detectors are then explored, in an attempt to build a bridge between current detectors and what will be needed to support the research ambitions of astronomers in the future.

  16. Ground-based astrometry with the ASPHO: optical-radio reference systems connection.

    NASA Astrophysics Data System (ADS)

    Martin, V. A. F.; Leister, N. V.; Poppe, P. C. R.; Brito, A. A.; Mattos, L.

    2003-11-01

    Precise positions and proper motions of optical counterparts of radiostars are needed in order to determine a direct link between the radio reference frame (VLBI - Very long Baseline Interferometry) and the ground-based optical reference frame (based on fundamental stars) (Poma & Zanzu 1991, Kovalevsky 1990, Walter et al. 1990). The basic problems are concerning with the optical-radio systems connection and the quick deterioration that he Hipparcos system is subjected. Thus, there is a request of exact and systematic observations with the instruments in the Earth (Kovalevsky 1990). Radiostars are suitable intermediaries for linking optical stellar reference frame to the quasi-inertial radio reference frame (RRF) represented by compact extragalactic radio sources. With the goal of the connection radio-optical reference frames the observational programme has included a total of 36 radiostars.

  17. 45 CFR 287.130 - Can NEW Program activities include job market assessments, job creation and economic development...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 2 2011-10-01 2011-10-01 false Can NEW Program activities include job market assessments, job creation and economic development activities? 287.130 Section 287.130 Public Welfare... Program Design and Operations § 287.130 Can NEW Program activities include job market assessments,...

  18. 45 CFR 287.130 - Can NEW Program activities include job market assessments, job creation and economic development...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 2 2012-10-01 2012-10-01 false Can NEW Program activities include job market assessments, job creation and economic development activities? 287.130 Section 287.130 Public Welfare... Program Design and Operations § 287.130 Can NEW Program activities include job market assessments,...

  19. 45 CFR 287.130 - Can NEW Program activities include job market assessments, job creation and economic development...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 2 2010-10-01 2010-10-01 false Can NEW Program activities include job market assessments, job creation and economic development activities? 287.130 Section 287.130 Public Welfare... Program Design and Operations § 287.130 Can NEW Program activities include job market assessments,...

  20. 45 CFR 287.130 - Can NEW Program activities include job market assessments, job creation and economic development...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 2 2014-10-01 2012-10-01 true Can NEW Program activities include job market assessments, job creation and economic development activities? 287.130 Section 287.130 Public Welfare... Program Design and Operations § 287.130 Can NEW Program activities include job market assessments,...

  1. 45 CFR 287.130 - Can NEW Program activities include job market assessments, job creation and economic development...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 2 2013-10-01 2012-10-01 true Can NEW Program activities include job market assessments, job creation and economic development activities? 287.130 Section 287.130 Public Welfare... Program Design and Operations § 287.130 Can NEW Program activities include job market assessments,...

  2. Synergic use of satellite and ground based remote sensing methods for monitoring the San Leo rock cliff (Northern Italy)

    NASA Astrophysics Data System (ADS)

    Frodella, William; Ciampalini, Andrea; Gigli, Giovanni; Lombardi, Luca; Raspini, Federico; Nocentini, Massimiliano; Scardigli, Cosimo; Casagli, Nicola

    2016-07-01

    The historic town of San Leo (Emilia Romagna Region, northern Italy) is located on top of an isolated rock massif above the Marecchia River valley hillside. On February 27th 2014, a northeastern sector of the massif collapsed; minor structural damages were reported in the town and a few buildings were evacuated as a precautionary measure. Although no fatalities occurred and the San Leo cultural heritage suffered no damage, minor rock fall events kept taking place on the newly formed rock wall, worsening this hazardous situation. In this framework, a monitoring system based on remote sensing techniques, such as radar interferometry (both spaceborne and ground-based) and terrestrial laser scanning, was planned in order to monitor the ground deformation of the investigated area and to evaluate the residual risk. In this paper the main outlines of a 1-year monitoring activity are described, including a pre-event analysis of possible landslide precursors and a post-event analysis of the displacements of both the collapse-affected rock wall sector and the rock fall deposits.

  3. The cost of developing and maintain the monitoring and control software of large ground-based telescopes

    NASA Astrophysics Data System (ADS)

    Guzman, Juan Carlos; Chiozzi, Gianluca; Bridger, Alan; Ibsen, Jorge

    2014-07-01

    There are several large ground-based telescopes currently under development such as the SKA and CCAT in radio as well as several 30m-class in the optical. A common challenge that all of these telescopes are facing is estimating the cost of design, construction and maintenance of their required software. This paper will present a cost breakdown of the monitoring and control software packages implemented for ASKAP including the effort spent to develop and maintain the in-house code and the effort saved by using third-party software, such as EPICS. The costing for ASKAP will be compared to those for the monitoring and control software of other large ground-based telescopes such as ALMA and VLT. This comparison will highlight trends and commonalities in the costing and provides a useful guide for costing future telescope control software builds or upgrades and the ongoing maintenance cost.

  4. System-level view of geospace dynamics: Challenges for high-latitude ground-based observations

    NASA Astrophysics Data System (ADS)

    Donovan, E.

    2014-12-01

    Increasingly, research programs including GEM, CEDAR, GEMSIS, GO Canada, and others are focusing on how geospace works as a system. Coupling sits at the heart of system level dynamics. In all cases, coupling is accomplished via fundamental processes such as reconnection and plasma waves, and can be between regions, energy ranges, species, scales, and energy reservoirs. Three views of geospace are required to attack system level questions. First, we must observe the fundamental processes that accomplish the coupling. This "observatory view" requires in situ measurements by satellite-borne instruments or remote sensing from powerful well-instrumented ground-based observatories organized around, for example, Incoherent Scatter Radars. Second, we need to see how this coupling is controlled and what it accomplishes. This demands quantitative observations of the system elements that are being coupled. This "multi-scale view" is accomplished by networks of ground-based instruments, and by global imaging from space. Third, if we take geospace as a whole, the system is too complicated, so at the top level we need time series of simple quantities such as indices that capture important aspects of the system level dynamics. This requires a "key parameter view" that is typically provided through indices such as AE and DsT. With the launch of MMS, and ongoing missions such as THEMIS, Cluster, Swarm, RBSP, and ePOP, we are entering a-once-in-a-lifetime epoch with a remarkable fleet of satellites probing processes at key regions throughout geospace, so the observatory view is secure. With a few exceptions, our key parameter view provides what we need. The multi-scale view, however, is compromised by space/time scales that are important but under-sampled, combined extent of coverage and resolution that falls short of what we need, and inadequate conjugate observations. In this talk, I present an overview of what we need for taking system level research to its next level, and how

  5. Towards a Handshake of Ground-Based Measurements and Remote-Sensing of Vegetation Traits at Global Scale?

    NASA Astrophysics Data System (ADS)

    Kattge, J.; Díaz, S.; Lavorel, S.; Prentice, I. C.; Leadley, P.; Reich, P. B.; Banerjee, A.; Fazayeli, F.; Schrodt, F. I.; Joswig, J.; Mahecha, M. D.; Wirth, C.

    2014-12-01

    Plant traits determine how primary producers respond to environmental factors, affect other trophic levels, influence ecosystem processes and services, and provide a link from species richness to ecosystem functional diversity. Plant traits thus are a key to understand and predict the adaptation of ecosystems to environmental changes. At the same time ground based measurements of plant trait data are dispersed over a wide range of databases, many of these not publicly available. To overcome this deficiency IGBP and DIVERSITAS have initiated the development of a joint database, called TRY, aiming at constructing a standard resource of ground based plant trait observations for the ecological community and for the development of global vegetation models. So far the TRY initiative has united a wide range of the plant trait research community worldwide and gained an unprecedented buy-in of trait data: about 250 trait databases have been contributed and the data repository currently contains about 5.6 million trait entries for 90,000 out of the world's 350,000 plant species. The database includes data for 1100 traits, characterizing the vegetative and regeneration stages of the plant life cycle, including growth, dispersal, establishment and persistence. Based on advanced methods for gap-filling and spatial extrapolation currently being developed in applied statistics and machine learning and in combination with environmental information and species distribution ranges, the unprecedented availability of ground based trait measurements is expected to allow for up-scaling of trait observations from plant to ecosystem level and from point measurements to regional and global scales. These up-scaled data products are expected to provide a link from ground based trait measurements to remote sensing of vegetation function and traits with global coverage.

  6. Ground-Based Icing Condition Remote Sensing System Definition

    NASA Technical Reports Server (NTRS)

    Reehorst, Andrew L.; Koenig, George G.

    2001-01-01

    This report documents the NASA Glenn Research Center activities to assess and down select remote sensing technologies for the purpose of developing a system capable of measuring icing condition hazards aloft. The information generated by such a remote sensing system is intended for use by the entire aviation community, including flight crews. air traffic controllers. airline dispatchers, and aviation weather forecasters. The remote sensing system must be capable of remotely measuring temperature and liquid water content (LWC), and indicating the presence of super-cooled large droplets (SLD). Technologies examined include Profiling Microwave Radiometer, Dual-Band Radar, Multi-Band Radar, Ka-Band Radar. Polarized Ka-Band Radar, and Multiple Field of View (MFOV) Lidar. The assessment of these systems took place primarily during the Mt. Washington Icing Sensors Project (MWISP) in April 1999 and the Alliance Icing Research Study (AIRS) from November 1999 to February 2000. A discussion of the various sensing technologies is included. The result of the assessment is that no one sensing technology can satisfy all of the stated project goals. Therefore a proposed system includes radiometry and Ka-band radar. A multilevel approach is proposed to allow the future selection of the fielded system based upon required capability and available funding. The most basic level system would be the least capable and least expensive. The next level would increase capability and cost, and the highest level would be the most capable and most expensive to field. The Level 1 system would consist of a Profiling Microwave Radiometer. The Level 2 system would add a Ka-Band Radar. The Level 3 system would add polarization to the Ka-Band Radar. All levels of the system would utilize hardware that is already under development by the U.S. Government. However, to meet the needs of the aviation community, all levels of the system will require further development. In addition to the proposed system

  7. Plans of a test bed for ionospheric modelling based on Fennoscandian ground-based instrumentation

    NASA Astrophysics Data System (ADS)

    Kauristie, Kirsti; Kero, Antti; Verronen, Pekka T.; Aikio, Anita; Vierinen, Juha; Lehtinen, Markku; Turunen, Esa; Pulkkinen, Tuija; Virtanen, Ilkka; Norberg, Johannes; Vanhamäki, Heikki; Kallio, Esa; Kestilä, Antti; Partamies, Noora; Syrjäsuo, Mikko

    2016-07-01

    One of the recommendations for teaming among research groups in the COSPAR/ILWS roadmap is about building test beds in which coordinated observing supports model development. In the presentation we will describe a test bed initiative supporting research on ionosphere-thermosphere-magnetosphere interactions. The EISCAT incoherent scatter radars with their future extension, EISCAT3D, form the backbone of the proposed system. The EISCAT radars are surrounded by versatile and dense arrays of ground-based instrumentation: magnetometers and auroral cameras (the MIRACLE and IMAGE networks), ionospheric tomography receivers (the TomoScand network) and other novel technology for upper atmospheric probing with radio waves (e.g. the KAIRA facility, riometers and the ionosonde maintained by the Sodankylä Geophysical Observatory). As a new opening, close coordination with the Finnish national cubesat program is planned. We will investigate opportunities to establish a cost efficient nanosatellite program which would support the ground-based observations in a systematic and persistent manner. First experiences will be gathered with the Aalto-1 and Aalto-2 satellites, latter of which will be the Finnish contribution to the international QB50 mission. We envisage close collaboration also in the development of data analysis tools with the goal to integrate routines and models from different research groups to one system, where the different elements support each other. In the longer run we are aiming for a modelling framework with observational guidance which gives a holistic description on ionosphere-thermosphere processes and this way enables reliable forecasts on upper atmospheric space weather activity.

  8. Combination of ground-based and satellite remote sensing measurements over Limassol

    NASA Astrophysics Data System (ADS)

    Nisantzi, Argyro; Mamouri, Rodanthi E.; Akylas, Evangelos; Hadjimitsis, Diofantos G.

    2013-08-01

    According to the International Panel of Climate Change (IPCC, 2007) there are still uncertainties in climate change predictions due to the impact of aerosols in the solar irradiance. The scattering procedure of aerosols depends strongly on their shape and size distribution while lidar techniques could give the vertical distribution of them. Southeastern Mediterranean is affected by air masses of different sources thus layers with complicate aerosol composition are frequently observed over Cyprus. A backscatter lidar has been established at Cyprus University of Technology's (CUT) premises (34°N, 33°E) since 2010, in order to provide vertical profiles of the aerosol optical properties such as backscatter coefficient and particle depolarization ratio. More than 2 years of daily measurements have been analyzed for the period of May 2010 to May 2012. From this dataset, there are almost 45 CALISPO coincidence overpasses at a distance of less than 105km from the location of the ground-based lidar and from those two cases were selected. Both, ground based and space born active remote sensing techniques were used in order to characterize aerosol layers in the free troposphere over SE Mediterranean. The layers of CALIPSO and CUT's lidar observations have been examined with respect to their origin, in order to retrieve the backscatter coefficient and the particle depolarization ratio at 532nm. The analysis of the presented cases, together with the air mass back-trajectories calculations, in accordance with depolarization retrievals, show that non-spherical particles originated from Africa whereas marine layer consist of spherical particles. Furthermore aerosol optical properties such as Ångström exponents (AE) derived from the sun-photometer belonging to the AERONET network at Limassol city were used complementary in order to support our analysis.

  9. High Resolution Spectral Analysis of Hiss and Chorus Emissions in Ground Based Data

    NASA Astrophysics Data System (ADS)

    Hosseini Aliabad, S. P.; Golkowski, M.; Gibby, A. R.

    2015-12-01

    The dynamic evolution of the radiation belts is believed to be controlled in large part by two separate but related classes of naturally occurring plasma waves: ELF/VLF chorus and hiss emissions. Although whistler mode chorus has been extensively studied since the first reports by Storey in 1953, the source mechanism and properties are still subjects of active research. Moreover, the origin of plasmaspheric hiss, the electromagnetic emission believed to be responsible for the gap between the inner and outer radiation belts, has been debated for over four decades. Although these waves can be observed in situ on spacecraft, ground-based observing stations can provide orders of magnitude higher data volumes and decades long data coverage essential for certain long-term and statistical studies of wave properties. Recent observational and theoretical works suggest that high resolution analysis of the spectral features of both hiss and chorus emissions can provide insight into generation processes and be used to validate existing theories. Application of the classic Fourier (FFT) technique unfortunately yields a tradeoff between time and frequency resolution. In additional to Fourier spectra, we employ novel methods to make spectrograms with high time and frequency resolutions, independently using minimum variance distortionless response (MVDR). These techniques are applied to ground based data observations of hiss and chorus made in Alaska. Plasmaspheric hiss has been widely regarded as a broadband, structure less, incoherent emission. We quantify the extent to which plasmaspheric hiss can be a coherent emission with complex fine structure. Likewise, to date, researchers have differentiated between hiss and chorus coherency primarily using qualitative "naked eye" approaches to amplitude spectra. Using a quantitative approach to observed amplitude and we present more rigorous classification criteria for these emissions.

  10. Density and crosswind from GOCE - comparisons with other satellite data, ground-based observations and models

    NASA Astrophysics Data System (ADS)

    Doornbos, E.; Bruinsma, S.; Conde, M.; Forbes, J. M.

    2013-12-01

    Observations made by the European Space Agency (ESA) Gravity field and Ocean Circulation Explorer (GOCE) satellite have enabled the production of a spin-off product of high resolution and high accuracy data on thermosphere density, derived from aerodynamic analysis of acceleration measurements. In this regard, the mission follows in the footsteps of the earlier accelerometer-carrying gravity missions CHAMP and GRACE. The extremely high accuracy and redundancy of the six accelerometers carried by GOCE in its gravity gradiometer instrument has provided new insights on the performance and calibration of these instruments. Housekeeping data on the activation of the GOCE drag free control thruster, made available by ESA has made the production of the thermosphere data possible. The long duration low altitude of GOCE, enabled by its drag free control system, has ensured the presence of very large aerodynamic accelerations throughout its lifetime. This has been beneficial for the accurate derivation of data on the wind speed encountered by the satellite. We have compared the GOCE density observations with data from CHAMP and GRACE. The crosswind data has been compared with CHAMP observations, as well as ground-based observations, made using Scanning Doppler Imagers in Alaska. Models of the thermosphere can provide a bigger, global picture, required as a background in the interpretation of the local space- and ground-based measurements. The comparison of these different sources of information on thermosphere density and wind, each with their own strengths and weaknesses, can provide scientific insight, as well as inputs for further refinement of the processing algorithms and models that are part of the various techniques. Density and crosswind data derived from GOCE (dusk-dawn) and CHAMP (midnight-noon) satellite accelerometer data, superimposed over HWM07 modelled horizontal wind vectors.

  11. Ground-based observations of overshooting convection during the Tropical Warm Pool-International Cloud Experiment

    NASA Astrophysics Data System (ADS)

    Hassim, M. E. E.; Lane, T. P.; May, P. T.

    2014-01-01

    This study uses gridded radar data to investigate the properties of deep convective storms that penetrate the tropical tropopause layer (TTL) and overshoot the cold-point tropopause during the Tropical Warm Pool-International Cloud Experiment (TWP-ICE). Overshooting convection during the observed break period is relatively more intense and exhibits lesser diurnal variability than severe monsoonal storms in terms of mean overshooting area in the TTL (as covered by >20 dBZ echoes). However, ground-based radar has geometrical constraints and sampling gaps at high altitude that lead to biases in the final radar product. Using synthetic observations derived from model-based data, ground-based radar is shown to underestimate the mean overshooting area in the TTL across both TWP-ICE regimes. Differences range from ˜180 km2 (˜100 km2) to ˜14 km2 (˜8 km2) between 14 and 18 km for the active (break) period. This implies that the radar is underestimating the transport of water and ice mass into the TTL by convective overshoots during TWP-ICE. The synthetic data is also used to correct profiles of the mean observed overshooting area. These are shown to differ only marginally between the two sampled regimes once the influence of a large mesoscale convective system, considered as a departure from normal monsoon behavior, was removed from the statistics. The results of our study provide a useful cross-validation comparison for satellite-based detections of overshooting top areas over Darwin, Australia.

  12. Ground-based monitoring of solar radiation in Moldova

    NASA Astrophysics Data System (ADS)

    Aculinin, Alexandr; Smicov, Vladimir

    2010-05-01

    Integrated measurements of solar radiation in Kishinev, Moldova have been started by Atmospheric Research Group (ARG) at the Institute of Applied Physics from 2003. Direct, diffuse and total components of solar and atmospheric long-wave radiation are measured by using of the radiometric complex at the ground-based solar radiation monitoring station. Measurements are fulfilled at the stationary and moving platforms equipped with the set of 9 broadband solar radiation sensors overlapping wavelength range from UV-B to IR. Detailed description of the station can be found at the site http://arg.phys.asm.md. Ground station is placed in an urban environment of Kishinev city (47.00N; 28.56E). Summary of observation data acquired at the station in the course of short-term period from 2004 to 2009 are presented below. Solar radiation measurements were fulfilled by using CM11(280-3000 nm) and CH1 sensors (Kipp&Zonen). In the course of a year maximum and minimum of monthly sums of total radiation was ~706.4 MJm-2 in June and ~82.1MJm-2 in December, respectively. Monthly sums of direct solar radiation (on horizontal plane) show the maximum and minimum values of the order ~456.9 MJm-2 in July and ~25.5MJm-2 in December, respectively. In an average, within a year should be marked the predominance of direct radiation over the scattered radiation, 51% and 49%, respectively. In the course of a year, the percentage contribution of the direct radiation into the total radiation is ~55-65% from May to September. In the remaining months, the percentage contribution decreases and takes the minimum value of ~ 28% in December. In an average, annual sum of total solar radiation is ~4679.9 MJm-2. For the period from April to September accounts for ~76% of the annual amount of total radiation. Annual sum of sunshine duration accounts for ~2149 hours, which is of ~ 48% from the possible sunshine duration. In an average, within a year maximum and minimum of sunshine duration is ~ 304 hours in

  13. Using Assistive Technology Adaptations To Include Students with Learning Disabilities in Cooperative Learning Activities.

    ERIC Educational Resources Information Center

    Bryant, Diane Pedrotty; Bryant, Brian R.

    1998-01-01

    Discusses a process for integrating technology adaptations for students with learning disabilities into cooperative-learning activities in terms of three components: (1) selecting adaptations; (2) monitoring use of adaptations during cooperative-learning activities; and (3) evaluating the adaptations' effectiveness. Barriers to and support systems…

  14. Microwave signatures of ice hydrometeors from ground-based observations above Summit, Greenland

    NASA Astrophysics Data System (ADS)

    Pettersen, Claire; Bennartz, Ralf; Kulie, Mark S.; Merrelli, Aronne J.; Shupe, Matthew D.; Turner, David D.

    2016-04-01

    Multi-instrument, ground-based measurements provide unique and comprehensive data sets of the atmosphere for a specific location over long periods of time and resulting data compliment past and existing global satellite observations. This paper explores the effect of ice hydrometeors on ground-based, high-frequency passive microwave measurements and attempts to isolate an ice signature for summer seasons at Summit, Greenland, from 2010 to 2013. Data from a combination of passive microwave, cloud radar, radiosonde, and ceilometer were examined to isolate the ice signature at microwave wavelengths. By limiting the study to a cloud liquid water path of 40 g m-2 or less, the cloud radar can identify cases where the precipitation was dominated by ice. These cases were examined using liquid water and gas microwave absorption models, and brightness temperatures were calculated for the high-frequency microwave channels: 90, 150, and 225 GHz. By comparing the measured brightness temperatures from the microwave radiometers and the calculated brightness temperature using only gas and liquid contributions, any residual brightness temperature difference is due to emission and scattering of microwave radiation from the ice hydrometeors in the column. The ice signature in the 90, 150, and 225 GHz channels for the Summit Station summer months was isolated. This measured ice signature was then compared to an equivalent brightness temperature difference calculated with a radiative transfer model including microwave single-scattering properties for several ice habits. Initial model results compare well against the 4 years of summer season isolated ice signature in the high-frequency microwave channels.

  15. Ground-based remote sensing of thin clouds in the Arctic

    NASA Astrophysics Data System (ADS)

    Garrett, T. J.; Zhao, C.

    2013-05-01

    This paper describes a method for using interferometer measurements of downwelling thermal radiation to retrieve the properties of single-layer clouds. Cloud phase is determined from ratios of thermal emission in three "micro-windows" at 862.5 cm-1, 935.8 cm-1, and 988.4 cm-1 where absorption by water vapour is particularly small. Cloud microphysical and optical properties are retrieved from thermal emission in the first two of these micro-windows, constrained by the transmission through clouds of primarily stratospheric ozone emission at 1040 cm-1. Assuming a cloud does not approximate a blackbody, the estimated 95% confidence retrieval errors in effective radius re, visible optical depth τ, number concentration N, and water path WP are, respectively, 10%, 20%, 38% (55% for ice crystals), and 16%. Applied to data from the Atmospheric Radiation Measurement programme (ARM) North Slope of Alaska - Adjacent Arctic Ocean (NSA-AAO) site near Barrow, Alaska, retrievals show general agreement with both ground-based microwave radiometer measurements of liquid water path and a method that uses combined shortwave and microwave measurements to retrieve re, τ and N. Compared to other retrieval methods, advantages of this technique include its ability to characterise thin clouds year round, that water vapour is not a primary source of retrieval error, and that the retrievals of microphysical properties are only weakly sensitive to retrieved cloud phase. The primary limitation is the inapplicability to thicker clouds that radiate as blackbodies and that it relies on a fairly comprehensive suite of ground based measurements.

  16. Observation of coastal fogs using a suite of ground based remote sensing instruments

    NASA Astrophysics Data System (ADS)

    Song, J. I.; Yum, S. S.; Kim, K. H.; Kim, Y. H.; Cho, C. H.; Oh, S. B.

    2014-12-01

    Fog is the cloud of which the base is at the earth surface. Because of severely reduced visibility when fog is present, on-road traffics, maritime transport and aircraft operations are often hampered by fog occurrence. Therefore, accurate prediction of fog has been of high priority in traffic safety. The first step towards the accurate prediction of fog would be to detect the fog formation and monitor the evolution of fog in a continuous manner so that we can better characterize the fog formation mechanism. However, observing the evolution of fog has been difficult due to its nature of local meteorological scale and the lack of proper measurement of such scale. In situ measurements can provide us the most accurate data, but these measurements are limited to a very small spatial coverage. Satellite remote sensing can cover a wider spatial scale but detailed structure cannot be detected, In contrast, ground based remote sensing has advantages in spatial and temporal coverages. Here we present the data measured using a suite of ground based remote sensing instruments at the National Center for Intensive Observation of severe weather (NCIO), located at a southern coastal rural town of Boseong, Korea (34.76 ̊ N, 127.16 ̊ E), which include a scanning Ka-band cloud radar, wind profiler, microwave radiometer, ceilometer and lidar. Analysis of these data will be complemented by the basic meteorological (temperature, relative humidity, wind speed and direction) data measured at 11 different altitudes on a 300m meteorological observation tower installed at NCIO. With the sea to the south, the hilly topographical setting to the north, and the ragged coastal line in between, fog formation mechanisms in this region are expected to be very complex. Our eventual goal is to obtain an insight on the formation mechanisms of the coastal fogs in this region through the analysis of these comprehensive dataset. Some preliminary results from this effort will be presented at the

  17. Ground based mobile isotopic methane measurements in the Front Range, Colorado

    NASA Astrophysics Data System (ADS)

    Vaughn, B. H.; Rella, C.; Petron, G.; Sherwood, O.; Mielke-Maday, I.; Schwietzke, S.

    2014-12-01

    Increased development of unconventional oil and gas resources in North America has given rise to attempts to monitor and quantify fugitive emissions of methane from the industry. Emission estimates of methane from oil and gas basins can vary significantly from one study to another as well as from EPA or State estimates. New efforts are aimed at reconciling bottom-up, or inventory-based, emission estimates of methane with top-down estimates based on atmospheric measurements from aircraft, towers, mobile ground-based vehicles, and atmospheric models. Attributing airborne measurements of regional methane fluxes to specific sources is informed by ground-based measurements of methane. Stable isotopic measurements (δ13C) of methane help distinguish between emissions from the O&G industry, Confined Animal Feed Operations (CAFO), and landfills, but analytical challenges typically limit meaningful isotopic measurements to individual point sampling. We are developing a toolbox to use δ13CH4 measurements to assess the partitioning of methane emissions for regions with multiple methane sources. The method was applied to the Denver-Julesberg Basin. Here we present data from continuous isotopic measurements obtained over a wide geographic area by using MegaCore, a 1500 ft. tube that is constantly filled with sample air while driving, then subsequently analyzed at slower rates using cavity ring down spectroscopy (CRDS). Pressure, flow and calibration are tightly controlled allowing precise attribution of methane enhancements to their point of collection. Comparisons with point measurements are needed to confirm regional values and further constrain flux estimates and models. This effort was made in conjunction with several major field campaigns in the Colorado Front Range in July-August 2014, including FRAPPÉ (Front Range Air Pollution and Photochemistry Experiment), DISCOVER-AQ, and the Air Water Gas NSF Sustainability Research Network at the University of Colorado.

  18. Nutritional status assessment in semiclosed environments: ground-based and space flight studies in humans

    NASA Technical Reports Server (NTRS)

    Smith, S. M.; Davis-Street, J. E.; Rice, B. L.; Nillen, J. L.; Gillman, P. L.; Block, G.

    2001-01-01

    Adequate nutrition is critical during long-term spaceflight, as is the ability to easily monitor dietary intake. A comprehensive nutritional status assessment profile was designed for use before, during and after flight. It included assessment of both dietary intake and biochemical markers of nutritional status. A spaceflight food-frequency questionnaire (FFQ) was developed to evaluate intake of key nutrients during spaceflight. The nutritional status assessment protocol was evaluated during two ground-based closed-chamber studies (60 and 91 d; n = 4/study), and was implemented for two astronauts during 4-mo stays on the Mir space station. Ground-based studies indicated that the FFQ, administered daily or weekly, adequately estimated intake of key nutrients. Chamber subjects maintained prechamber energy intake and body weight. Astronauts tended to eat 40--50% of WHO-predicted energy requirements, and lost >10% of preflight body mass. Serum ferritin levels were lower after the chamber stays, despite adequate iron intake. Red blood cell folate concentrations were increased after the chamber studies. Vitamin D stores were decreased by > 40% on chamber egress and after spaceflight. Mir crew members had decreased levels of most nutritional indices, but these are difficult to interpret given the insufficient energy intake and loss of body mass. Spaceflight food systems can provide adequate intake of macronutrients, although, as expected, micronutrient intake is a concern for any closed or semiclosed food system. These data demonstrate the utility and importance of nutritional status assessment during spaceflight and of the FFQ during extended-duration spaceflight.

  19. The Shear Testing Programme - I. Weak lensing analysis of simulated ground-based observations

    NASA Astrophysics Data System (ADS)

    Heymans, Catherine; Van Waerbeke, Ludovic; Bacon, David; Berge, Joel; Bernstein, Gary; Bertin, Emmanuel; Bridle, Sarah; Brown, Michael L.; Clowe, Douglas; Dahle, Håkon; Erben, Thomas; Gray, Meghan; Hetterscheidt, Marco; Hoekstra, Henk; Hudelot, Patrick; Jarvis, Mike; Kuijken, Konrad; Margoniner, Vera; Massey, Richard; Mellier, Yannick; Nakajima, Reiko; Refregier, Alexandre; Rhodes, Jason; Schrabback, Tim; Wittman, David

    2006-05-01

    The Shear Testing Programme (STEP) is a collaborative project to improve the accuracy and reliability of all weak lensing measurements in preparation for the next generation of wide-field surveys. In this first STEP paper, we present the results of a blind analysis of simulated ground-based observations of relatively simple galaxy morphologies. The most successful methods are shown to achieve percent level accuracy. From the cosmic shear pipelines that have been used to constrain cosmology, we find weak lensing shear measured to an accuracy that is within the statistical errors of current weak lensing analyses, with shear measurements accurate to better than 7 per cent. The dominant source of measurement error is shown to arise from calibration uncertainties where the measured shear is over or underestimated by a constant multiplicative factor. This is of concern as calibration errors cannot be detected through standard diagnostic tests. The measured calibration errors appear to result from stellar contamination, false object detection, the shear measurement method itself, selection bias and/or the use of biased weights. Additive systematics (false detections of shear) resulting from residual point-spread function anisotropy are, in most cases, reduced to below an equivalent shear of 0.001, an order of magnitude below cosmic shear distortions on the scales probed by current surveys. Our results provide a snapshot view of the accuracy of current ground-based weak lensing methods and a benchmark upon which we can improve. To this end we provide descriptions of each method tested and include details of the eight different implementations of the commonly used Kaiser, Squires & Broadhurst method (KSB+) to aid the improvement of future KSB+ analyses.

  20. Estimating surface visibility at Hong Kong from ground-based LIDAR, sun photometer and operational MODIS products.

    PubMed

    Shahzad, Muhammad I; Nichol, Janet E; Wang, Jun; Campbell, James R; Chan, Pak W

    2013-09-01

    Hong Kong's surface visibility has decreased in recent years due to air pollution from rapid social and economic development in the region. In addition to deteriorating health standards, reduced visibility disrupts routine civil and public operations, most notably transportation and aviation. Regional estimates of visibility solved operationally using available ground and satellite-based estimates of aerosol optical properties and vertical distribution may prove more effective than standard reliance on a few existing surface visibility monitoring stations. Previous studies have demonstrated that such satellite measurements correlate well with near-surface optical properties, despite these sensors do not consider range-resolved information and indirect parameterizations necessary to solve relevant parameters. By expanding such analysis to include vertically resolved aerosol profile information from an autonomous ground-based lidar instrument, this work develops six models for automated assessment of surface visibility. Regional visibility is estimated using co-incident ground-based lidar, sun photometer visibility meter and MODerate-resolution maging Spectroradiometer (MODIS) aerosol optical depth data sets. Using a 355 nm extinction coefficient profile solved from the lidar MODIS AOD (aerosol optical depth) is scaled down to the surface to generate a regional composite depiction of surface visibility. These results demonstrate the potential for applying passive satellite depictions of broad-scale aerosol optical properties together with a ground-based surface lidar and zenith-viewing sun photometer for improving quantitative assessments of visibility in a city such as Hong Kong.

  1. Hubble Space Telescope Degradation Data Used for Ground-Based Durability Projection of Insulation on the International Space Station

    NASA Technical Reports Server (NTRS)

    deGroh, Kim K.; Banks, Bruce A.; Dever, Joyce A.; Hodermarsky, Janet C.

    2004-01-01

    Ground-based environmental durability tests have indicated that exposing materials in accelerated tests to known spacecraft mission degradation sources predicted by an environmental model does not simulate the extent of damage that occurs in the space environment. The reasons for this may include the complex nature of the space environment, which is not simulated completely in any ground-based facility, the extreme differences in exposure rates in space and in ground tests, and inaccuracies in environmental models. One approach to overcoming the difficulties in simulating the space environment using ground-based testing is to calibrate the facility using data from actual space-exposed materials to determine exposure levels required to replicate degraded properties observed in space. Research was conducted at the NASA Glenn Research Center to develop a ground-to-space correlation method that determines the durability of Teflon-based insulation for the International Space Station (ISS) by using data obtained in a ground facility and degraded Teflon thermal insulation retrieved from the Hubble Space Telescope.

  2. Diffractive laser beam homogenizer including a photo-active material and method of fabricating the same

    SciTech Connect

    Bayramian, Andy J; Ebbers, Christopher A; Chen, Diana C

    2014-05-20

    A method of manufacturing a plurality of diffractive optical elements includes providing a partially transmissive slide, providing a first piece of PTR glass, and directing first UV radiation through the partially transmissive slide to impinge on the first piece of PTR glass. The method also includes exposing predetermined portions of the first piece of PTR glass to the first UV radiation and thermally treating the exposed first piece of PTR glass. The method further includes providing a second piece of PTR glass and directing second UV radiation through the thermally treated first piece of PTR glass to impinge on the second piece of PTR glass. The method additionally includes exposing predetermined portions of the second piece of PTR glass to the second UV radiation, thermally treating the exposed second piece of PTR glass, and repeating providing and processing of the second piece of PTR glass using additional pieces of PTR glass.

  3. In vitro and in vivo anti-plasmodial activity of essential oils, including hinokitiol.

    PubMed

    Fujisaki, Ryuichi; Kamei, Kiyoko; Yamamura, Mariko; Nishiya, Hajime; Inouye, Shigeharu; Takahashi, Miki; Abe, Shigeru

    2012-03-01

    Abstract. The anti-plasmodial activity of 47 essential oils and 10 of their constituents were screened for in vitro activity against Plasmodium falciparum. Five of these essential oils (sandalwood, caraway, monarda, nutmeg, and Thujopsis dolabrata var. hondai) and 2 constituents (thymoquinone and hinokitiol) were found to be active against P. falciparum in vitro, with 50% inhibitory concentration (IC50) values equal to or less than 1.0 microg/ml. Furthermore, in vivo analysis using a rodent model confirmed the anti-plasmodial potential of subcutaneously administered sandalwood oil, and percutaneously administered hinokitiol and caraway oil against rodent P. berghei. Notably, these oils showed no efficacy when administered orally, intraperitoneally or intravenously. Caraway oil and hinokitiol dissolved in carrier oil, applied to the skin of hairless mice caused high levels in the blood, with concentrations exceeding their IC50 values. PMID:23082579

  4. In vitro and in vivo anti-plasmodial activity of essential oils, including hinokitiol.

    PubMed

    Fujisaki, Ryuichi; Kamei, Kiyoko; Yamamura, Mariko; Nishiya, Hajime; Inouye, Shigeharu; Takahashi, Miki; Abe, Shigeru

    2012-03-01

    Abstract. The anti-plasmodial activity of 47 essential oils and 10 of their constituents were screened for in vitro activity against Plasmodium falciparum. Five of these essential oils (sandalwood, caraway, monarda, nutmeg, and Thujopsis dolabrata var. hondai) and 2 constituents (thymoquinone and hinokitiol) were found to be active against P. falciparum in vitro, with 50% inhibitory concentration (IC50) values equal to or less than 1.0 microg/ml. Furthermore, in vivo analysis using a rodent model confirmed the anti-plasmodial potential of subcutaneously administered sandalwood oil, and percutaneously administered hinokitiol and caraway oil against rodent P. berghei. Notably, these oils showed no efficacy when administered orally, intraperitoneally or intravenously. Caraway oil and hinokitiol dissolved in carrier oil, applied to the skin of hairless mice caused high levels in the blood, with concentrations exceeding their IC50 values.

  5. Electrode including porous particles with embedded active material for use in a secondary electrochemical cell

    DOEpatents

    Vissers, Donald R.; Nelson, Paul A.; Kaun, Thomas D.; Tomczuk, Zygmunt

    1978-04-25

    Particles of carbonaceous matrices containing embedded electrode active material are prepared for vibratory loading within a porous electrically conductive substrate. In preparing the particles, active materials such as metal chalcogenides, solid alloys of alkali or alkaline earth metals along with other metals and their oxides in powdered or particulate form are blended with a thermosetting resin and particles of a volatile to form a paste mixture. The paste is heated to a temperature at which the volatile transforms into vapor to impart porosity at about the same time as the resin begins to cure into a rigid, solid structure. The solid structure is then comminuted into porous, carbonaceous particles with the embedded active material.

  6. NASA HRP Plans for Collaboration at the IBMP Ground-Based Experimental Facility (NEK)

    NASA Technical Reports Server (NTRS)

    Cromwell, Ronita L.

    2016-01-01

    NASA and IBMP are planning research collaborations using the IBMP Ground-based Experimental Facility (NEK). The NEK offers unique capabilities to study the effects of isolation on behavioral health and performance as it relates to spaceflight. The NEK is comprised of multiple interconnected modules that range in size from 50-250m(sup3). Modules can be included or excluded in a given mission allowing for flexibility of platform design. The NEK complex includes a Mission Control Center for communications and monitoring of crew members. In an effort to begin these collaborations, a 2-week mission is planned for 2017. In this mission, scientific studies will be conducted to assess facility capabilities in preparation for longer duration missions. A second follow-on 2-week mission may be planned for early in 2018. In future years, long duration missions of 4, 8 and 12 months are being considered. Missions will include scenarios that simulate for example, transit to and from asteroids, the moon, or other interplanetary travel. Mission operations will be structured to include stressors such as, high workloads, communication delays, and sleep deprivation. Studies completed at the NEK will support International Space Station expeditions, and future exploration missions. Topics studied will include communication, crew autonomy, cultural diversity, human factors, and medical capabilities.

  7. Validation of the OMI-TOMS and OMI-DOAS total ozone column data using ground-based observations over China

    NASA Astrophysics Data System (ADS)

    Ma, Mingliang; Shi, Runhe; Gao, Wei

    2015-09-01

    This study evaluates the accuracy of total ozone column derived from Ozone Monitoring Instruments (OMI) with two algorithms: OMI Total Ozone Mapping Spectrometer (OMI-TOMS) and OMI Differential Optical Absorption Spectroscopy (OMI-DOAS), compared to ground-based Brewer and Dobson spectrophotometers located at eight China stations from July 2009 to December 2013, including Xianghe, Kunming, Mt.Waliguan, Lhasa, Taipei, Chengkung, Cape D'Aguilar and Longfengshan. Results showed that the agreement between OMI ozone data and ground-based measurements is excellent. Total ozone columns from both OMI-TOMS and OMI-DOAS data are on average about 1.5% lower than ground-based data. For both OMI ozone data products the SZA dependence of the mean relative differences (RD) between satellite data and the ground-based data is relative obvious when the SZA is larger than 50°. Similar to the SZA, the satellite view zenith angle (VZA) dependence of the mean relative differences (RD) between satellite and ground is relatively markedly when the VZA is smaller than 10° in eight stations. Finally, the dependence of the mean relative differences (RD) (-4.28% to 0.818%) between OMI-DOAS data and ground-based data for the total ozone column is remarkable. While for OMI-TOMS data the dependence is not obvious (the RD value varies from -3.30% to -0.676%).

  8. Physical Activity Programs in Higher Education: Modifying Net/Wall Games to Include Individuals with Disabilities

    ERIC Educational Resources Information Center

    Braga, Luciana; Tracy, Julia F.; Taliaferro, Andrea R.

    2015-01-01

    The growing number of students with disabilities in higher education settings has presented challenges for instructors with regards to appropriate inclusion. Concerning physical activity courses in higher education, instructors may not have the knowledge or resources to make modifications and accommodations that will ultimately result in…

  9. Observing a fictitious stressful event: haematological changes, including circulating leukocyte activation.

    PubMed

    Mian, Rubina; Shelton-Rayner, Graham; Harkin, Brendan; Williams, Paul

    2003-03-01

    The aim of this study was to assess the effect of watching a psychological stressful event on the activation of leukocytes in healthy human volunteers. Blood samples were obtained from 32 healthy male and female subjects aged between 20 and 26 years before, during and after either watching an 83-minute horror film that none of the subjects had previously seen (The Texas Chainsaw Massacre, 1974) or by sitting quietly in a room (control group). Total differential cell counts, leukocyte activation as measured by the nitroblue tetrazolium (NBT) test, heart rate and blood pressure (BP) measurements were taken at defined time points. There were significant increases in peripheral circulating leukocytes, the number of activated circulating leukocytes, haemoglobin (Hb) concentration and haematocrit (Hct) in response to the stressor. These were accompanied by significant increases in heart rate, systolic and diastolic BP (P<0.05 from baseline). This is the first reported study on the effects of observing a psychologically stressful, albeit fictitious event on circulating leukocyte numbers and the state of leukocyte activation as determined by the nitrotetrazolium test.

  10. Sixty Minutes of Physical Activity per Day Included within Preschool Academic Lessons Improves Early Literacy

    ERIC Educational Resources Information Center

    Kirk, Stacie M.; Kirk, Erik P.

    2016-01-01

    Background: The effects of increases in physical activity (PA) on early literacy skills in preschool children are not known. Methods: Fifty-four African-American preschool children from a low socioeconomic urban Head Start participated over 8 months. A 2-group, quasi-experimental design was used with one preschool site participating in the PA…

  11. Population and Human Development: A Course Curriculum Including Lesson Plans, Activities and Bibliography.

    ERIC Educational Resources Information Center

    Murphy, Elaine M.

    This course outline suggests materials and learning activities on the interrelated causes and consequences of population growth and other population concerns. Designed to educate general college audiences, it is also intended for use as a preservice course for teachers. In addition, the course can be modified for high school students. The course…

  12. 7 CFR 981.441 - Credit for market promotion activities, including paid advertising.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AGRICULTURE ALMONDS GROWN IN CALIFORNIA Administrative Rules and Regulations § 981.441 Credit for market... each activity shall be to promote the sale, consumption or use of California almonds, and nothing... in California almond growing counties with more than 1,000 bearing acres: Provided, That...

  13. 7 CFR 981.441 - Credit for market promotion activities, including paid advertising.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AGRICULTURE ALMONDS GROWN IN CALIFORNIA Administrative Rules and Regulations § 981.441 Credit for market... each activity shall be to promote the sale, consumption or use of California almonds, and nothing... in California almond growing counties with more than 1,000 bearing acres: Provided, That...

  14. 7 CFR 981.441 - Credit for market promotion activities, including paid advertising.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AGRICULTURE ALMONDS GROWN IN CALIFORNIA Administrative Rules and Regulations § 981.441 Credit for market... each activity shall be to promote the sale, consumption or use of California almonds, and nothing... in California almond growing counties with more than 1,000 bearing acres: Provided, That...

  15. 7 CFR 981.441 - Credit for market promotion activities, including paid advertising.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AGRICULTURE ALMONDS GROWN IN CALIFORNIA Administrative Rules and Regulations § 981.441 Credit for market... each activity shall be to promote the sale, consumption or use of California almonds, and nothing... in California almond growing counties with more than 1,000 bearing acres: Provided, That...

  16. Backyards and Butterflies: Ways to Include Children with Disabilities in Outdoor Activities.

    ERIC Educational Resources Information Center

    Greenstein, Doreen; And Others

    This sourcebook is designed for children, parents, and families, detailing ideas for outdoor play and learning activities, with emphasis on involving children with disabilities in outdoor play. A rural perspective permeates the guide, although each chapter contains ideas for making outdoor environments more accessible and safer for all children,…

  17. Beyond Right or Wrong: Challenges of Including Creative Design Activities in the Classroom

    ERIC Educational Resources Information Center

    Brennan, Karen

    2015-01-01

    In this article, we explore challenges encountered by K-12 educators in establishing classroom cultures that support creative learning activities with the Scratch programming language. Providing opportunities for students to understand and to build capacities for creative work was described by many of the teachers that we interviewed as a central…

  18. Scope of Jovian lightning observation by ground-based and spacecraft instruments

    NASA Astrophysics Data System (ADS)

    Fukuhara, T.; Takahashi, Y.; Sato, M.; Nakajima, K.

    2009-12-01

    It is suggested by recent observational and theoretical studies that the thunderstorms, i.e., strong moist convective clouds in Jupiter’s atmosphere are very important not only as an essential ingredient of meteorology of Jupiter but also as a potentially very useful “probe” of the water abundance of the deep atmosphere, which is crucial to constrain the behavior of volatiles in early solar system. We would propose the lightning observation with properly designed optical device onboard Jovian system orbiter and with the ground-based telescope. Based on detailed analysis of cloud motions by Galileo orbiter, Gierasch et al. proposed that the thunderstorms can produce the small scale eddies and ultimately drive the belt/zone structure. Moreover, the belt zone structure helps the development of thunderstorms in the belt region in accordance with observation; the belt/zone structure and thunderstorms may be in a symbiotic relation. This framework is a refined version of shallow origin theory, but, although it is a very fantastic idea, quantitative verification remains to be done. Most recent numerical modeling by our group calculated all three types of cloud, i.e., H2O, NH3, and, NH4SH. One of the most important findings is the existence of distinct, quasi-periodic temporal variation of the convective cloud activity; explosion of cloud activity extending all over the computational domain occurs separated by quiet period of order of 10 days. Another surprising finding is that the period of the active/break cycle is roughly proportional to the amount of condensable component in the sub-cloud layer. This strong correspondence between the deep volatile abundance and temporal variability of cloud convection implies a new method to probe the deep atmosphere. We believe JGO with other optical equipments especially for atmospheric spectral imaging is the ideal platform for the lightning detector. Comparing quantitative lightning activity with ambient cloud motion and

  19. Uplink Array Demonstration with Ground-Based Calibration

    NASA Astrophysics Data System (ADS)

    D'Addario, L.; Proctor, R.; Trinh, J.; Sigman, E.; Yamamoto, C.

    2009-02-01

    A set of small, separately steerable reflector antennas has been used as a transmitting phased array for the purpose of demonstrating techniques that can be used in a larger array to serve the future uplink transmission needs of NASA's Deep Space Network. We envision an operational array with 100 or more antennas that could generate the order of 1 TW of effective isotropic radiated power (EIRP). The demonstration is a small-scale version of this with five antennas and about 1 MW of EIRP. Each antenna has a 1.2-m-diameter aperture and a 2-W power amplifier, and the array operates in the 14.0- to 14.5-GHz communication satellite band. The main technical challenge for an uplink array is to ensure that the carrier phases of the signals from all antenna elements are aligned when the signals arrive at the receiver on a distant spacecraft. This requires a method of phase calibration. In the demonstration, we have shown that active receivers attached to the Earth near the array can be used as calibration targets. Measurements made at these receivers have been successfully used to calculate the phase adjustment needed at each antenna to achieve the desired alignment, even though the destination spacecraft is in a direction and at a distance very different from that of the calibrator. When the calculated adjustments are applied at the antennas, the combined power at a spacecraft has been shown to be within 1 dB of that expected for perfect alignment. Commercial satellites in geostationary Earth orbit were used for these tests. Other objectives of the demonstration, all successfully accomplished, include: (1) Show that a new and simple electronics architecture, specifically designed for phase and delay stability, can implement all functions of NASA deep space uplinks at low cost, supporting mass production for large arrays. (2) Show that phase alignment can be maintained for at least a few hours without recalibration. In fact, stability over several days has been demonstrated

  20. Space Resources for Teachers: Biology, Including Suggestions for Classroom Activities and Laboratory Experiments.

    ERIC Educational Resources Information Center

    Lee, Tom E.; And Others

    This compilation of resource units concerns the latest developments in space biology. Some of the topics included are oxygen consumption, temperature, radiation, rhythms, weightlessness, acceleration and vibration stress, toxicity, and sensory and perceptual problems. Many of the topics are interdisciplinary and relate biology, physiology,…

  1. 7 CFR 981.441 - Credit for market promotion activities, including paid advertising.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... relations purposes, including E-commerce (mail ordering through the Internet): Provided, That Credit-Back...-Back is requested. (e) The following requirements shall apply to Credit-Back for all promotional... and Canada, paragraph (e)(5) of this section shall also apply. (2) The clear and evident purpose...

  2. In vitro bactericidal activity of aminoglycosides, including the next-generation drug plazomicin, against Brucella spp.

    PubMed

    Olsen, Steven C; Carlson, Steve A

    2015-01-01

    Plazomicin is a next-generation aminoglycoside with a potentially unique set of clinical characteristics compared with other aminoglycosides. This study assessed the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of plazomicin against 15 clinical isolates as well as three reference strains representing Brucella abortus, Brucella melitensis and Brucella suis. These data were compared with those obtained for six other aminoglycosides and two aminocyclitols. Plazomicin and gentamicin were the only drugs demonstrating bactericidal activity towards two of the three Brucella spp., whilst plazomicin was the only drug exhibiting bactericidal activity against B. suis. This is the first study to assess the bactericidal nature of plazomicin against Brucella spp. in vitro. PMID:25459738

  3. Analysis of Correlation between Ionospheric Spatial Gradients and Space Weather Intensity under Nominal Conditions for Ground-Based Augmentation Systems

    NASA Astrophysics Data System (ADS)

    Lee, J.

    2013-12-01

    Ground-Based Augmentation Systems (GBAS) support aircraft precision approach and landing by providing differential GPS corrections to aviation users. For GBAS applications, most of ionospheric errors are removed by applying the differential corrections. However, ionospheric correction errors may exist due to ionosphere spatial decorrelation between GBAS ground facility and users. Thus, the standard deviation of ionosphere spatial decorrelation (σvig) is estimated and included in the computation of error bounds on user position solution. The σvig of 4mm/km, derived for the Conterminous United States (CONUS), bounds one-sigma ionospheric spatial gradients under nominal conditions (including active, but not stormy condition) with an adequate safety margin [1]. The conservatism residing in the current σvig by fixing it to a constant value for all non-stormy conditions could be mitigated by subdividing ionospheric conditions into several classes and using different σvig for each class. This new concept, real-time σvig adaptation, will be possible if the level of ionospheric activity can be well classified based on space weather intensity. This paper studies correlation between the statistics of nominal ionospheric spatial gradients and space weather indices. The analysis was carried out using two sets of data collected from Continuous Operating Reference Station (CORS) Network; 9 consecutive (nominal and ionospherically active) days in 2004 and 19 consecutive (relatively 'quiet') days in 2010. Precise ionospheric delay estimates are obtained using the simplified truth processing method and vertical ionospheric gradients are computed using the well-known 'station pair method' [2]. The remaining biases which include carrier-phase leveling errors and Inter-frequency Bias (IFB) calibration errors are reduced by applying linear slip detection thresholds. The σvig was inflated to overbound the distribution of vertical ionospheric gradients with the required confidence

  4. Potential Application of NASA Aerospace Technology to Ground-Based Power System

    NASA Technical Reports Server (NTRS)

    Povinelli, Louis A.; Welch, Gerard E.; Bakhle, Milind A.; Brown, Gerald V.

    2000-01-01

    A review of some of the basic gas turbine technology being developed at the NASA John H. Glenn Research Center at Lewis Field, which may have the potential to be applied to ground-based systems, is presented in this paper. Only a sampling of the large number of research activities underway at the Glenn Research Center can be represented here. The items selected for presentation are those that may lead to increased power and efficiency, reduced cycle design time and cost, improved thermal design, reduced fatigue and fracture, reduced mechanical friction and increased operating margin. The topic of improved material will be presented in this conference and shall not be discussed here. The topics selected for presentation are key research activities at the Glenn Center of Excellence on Turbo-machinery. These activities should be of interest and utility to this ISABE (International Symposium on Air Breathing Engines) Special Forum on Aero-Derivative Land-Based Gas Turbines and to the power industry.

  5. Activity of faropenem tested against Neisseria gonorrhoeae isolates including fluoroquinolone-resistant strains.

    PubMed

    Jones, Ronald N; Critchley, Ian A; Whittington, William L H; Janjic, Nebojsa; Pottumarthy, Sudha

    2005-12-01

    We evaluated the anti-gonococcal potency of faropenem along with 7 comparator reference antimicrobials against a preselected collection of clinical isolates. The 265 isolates were inclusive of 2 subsets: 1) 76 well-characterized resistant phenotypes of gonococcal strains (53 quinolone-resistant strains--31 with documented quinolone resistance-determining region changes from Japan, 15 strains resistant to penicillin and tetracycline, and 8 strains with intermediate susceptibility to penicillin) and 2) 189 recent isolates from clinical specimens in 2004 from 6 states across the United States where quinolone resistance is prevalent. Activity of faropenem was adversely affected by l-cysteine hydrochloride in IsoVitaleX (4-fold increase in [minimal inhibitory concentration] MIC50; 0.06 versus 0.25 microg/mL). The rank order of potency of the antimicrobials for the entire collection was ceftriaxone (MIC90, 0.06 microg/mL) > faropenem (0.25 microg/mL) > azithromycin (0.5 microg/mL) > cefuroxime (1 microg/mL) > tetracycline (2 microg/mL) > penicillin = ciprofloxacin = levofloxacin (4 microg/mL). Using MIC90 for comparison, faropenem was 4-fold more potent than cefuroxime (0.25 versus 1 microg/mL), but was 4-fold less active than ceftriaxone (0.25 versus 0.06 microg/mL). Although the activity of faropenem was not affected by either penicillinase production (MIC90, 0.12 microg/mL, penicillinase-positive) or increasing ciprofloxacin MIC (0.25 microg/mL, ciprofloxacin-resistant), increasing penicillin MIC was associated with an increase in MIC90 values (0.016 microg/mL for penicillin-susceptible to 0.25 microg/mL for penicillin-resistant strains). Among the recent (2004) clinical gonococcal isolates tested, reduced susceptibility to penicillins, tetracycline, and fluoroquinolones was high (28.0-94.2%). Geographic distribution of the endemic resistance rates of gonococci varied considerably, with 16.7-66.7% of the gonococcal isolates being ciprofloxacin-resistant in Oregon

  6. Phytophthora infestans Has a Plethora of Phospholipase D Enzymes Including a Subclass That Has Extracellular Activity

    PubMed Central

    Meijer, Harold J. G.; Hassen, Hussen Harrun; Govers, Francine

    2011-01-01

    In eukaryotes phospholipase D (PLD) is involved in many cellular processes. Currently little is known about PLDs in oomycetes. Here we report that the oomycete plant pathogen Phytophthora infestans has a large repertoire of PLDs divided over six subfamilies: PXPH-PLD, PXTM-PLD, TM-PLD, PLD-likes, and type A and B sPLD-likes. Since the latter have signal peptides we developed a method using metabolically labelled phospholipids to monitor if P. infestans secretes PLD. In extracellular medium of ten P. infestans strains PLD activity was detected as demonstrated by the production of phosphatidic acid and the PLD specific marker phosphatidylalcohol. PMID:21423760

  7. Phytophthora infestans has a plethora of phospholipase D enzymes including a subclass that has extracellular activity.

    PubMed

    Meijer, Harold J G; Hassen, Hussen Harrun; Govers, Francine

    2011-01-01

    In eukaryotes phospholipase D (PLD) is involved in many cellular processes. Currently little is known about PLDs in oomycetes. Here we report that the oomycete plant pathogen Phytophthora infestans has a large repertoire of PLDs divided over six subfamilies: PXPH-PLD, PXTM-PLD, TM-PLD, PLD-likes, and type A and B sPLD-likes. Since the latter have signal peptides we developed a method using metabolically labelled phospholipids to monitor if P. infestans secretes PLD. In extracellular medium of ten P. infestans strains PLD activity was detected as demonstrated by the production of phosphatidic acid and the PLD specific marker phosphatidylalcohol. PMID:21423760

  8. Development of a Ground-Based Analog to the Advanced Resistive Exercise Device Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Newby, Nathaniel J.; Scott-Pandorf, M. M.; Caldwell, E.; DeWitt, J.K.; Fincke, R.; Peters, B.T.

    2010-01-01

    NASA and Wyle engineers constructed a Horizontal Exercise Fixture (HEF) that was patented in 2006. Recently modifications were made to HEF with the goal of creating a device that mimics squat exercise on the Advanced Resistive Exercise Device (ARED) and can be used by bed rest subjects who must remain supine during exercise. This project posed several engineering challenges, such as how best to reproduce the hip motions (we used a sled that allowed hip motion in the sagittal plane), how to counterweight the pelvis against gravity (we used a pulley and free-weight mechanism), and how to apply large loads (body weight plus squat load) to the shoulders while simultaneously supporting the back against gravity (we tested a standard and a safety bar that allowed movement in the subject s z-axis, both of which used a retractable plate for back support). METHODS An evaluation of the HEF was conducted with human subjects (3F, 3M), who performed sets of squat exercises of increasing load from 10-repetition maximum (RM) up to 1-RM. Three pelvic counterweight loads were tested along with each of the two back-support squat bars. Data collection included 3-dimensional ground reaction forces (GRF), muscle activation (EMG), body motion (video-based motion capture), and subjective comments. These data were compared with previous ground-based ARED study data. RESULTS All subjects in the evaluation were able to perform low- to high-loading squats on the HEF. Four of the 6 subjects preferred a pelvic counterweight equivalent to 60 percent of their body weight. Four subjects preferred the standard squat bar, whereas 2 female subjects preferred the safety bar. EMG data showed muscle activation in the legs and low back typical of squat motion. GRF trajectories and eccentric-concentric loading ratios were similar to ARED. CONCLUSION: Squat exercise performed on HEF approximated squat exercise on ARED.

  9. Long-Term and Transient Variability of the Low Ionosphere from Very Low Frequency Ground-Based Observations

    NASA Astrophysics Data System (ADS)

    Raulin, Jean Pierre

    2012-07-01

    At least three regions are forming the lower part of the ionosphere: the transient C-region at sunrise, the D-region during daytime and the bottom E-region at nighttime. These regions are accessible only through rocket in situ measurements and radio sounding techniques from the ground. Contrary to the upper layers, any prediction is difficult in the low ionosphere because of its important time variability, and its complex chemistry. In this work we will review the time variability of the low ionosphere on different timescales as deduced from Very Low Frequency ground based observations. Long-term variations are essentially due to the solar activity cycle and the solar rotation, and these variations reflect level changes of the ionizing Lyman-alpha radiation. On shorter transient timescales, solar flares and geomagnetic disturbances affect the low ionosphere when large amount of solar X-ray photons and/or particles are injected and deposit their energy at altitudes between 70 and 30 km. Then, the monitoring the low ionosphere regions may be used as an indirect and efficient tool to study space weather conditions. The transient time variability of the low ionosphere can also originate from below, that is due to the neutral atmosphere dynamics, which also includes meteorological phenomena. Then planetary and gravity waves can penetrate the lower ionosphere. To a lower extent, tidal oscillations and acoustic waves may affect the lowermost part of the ionosphere, although experimental researches in these domains are necessary. Finally, lightning induced perturbations of the low ionosphere will be discussed, and, these include sprites, transient gamma-ray flashes (TGF), blue elves and Lightning Precipitation Events (LPE).

  10. High resolution surface solar radiation patterns over Eastern Mediterranean: Satellite, ground-based, reanalysis data and radiative transfer simulations

    NASA Astrophysics Data System (ADS)

    Alexandri, G.; Georgoulias, A.; Meleti, C.; Balis, D.

    2013-12-01

    Surface solar radiation (SSR) and its long and short term variations play a critical role in the modification of climate and by extent of the social and financial life of humans. Thus, SSR measurements are of primary importance. SSR is measured for decades from ground-based stations for specific spots around the planet. During the last decades, satellite observations allowed for the assessment of the spatial variability of SSR at a global as well as regional scale. In this study, a detailed spatiotemporal view of the SSR over Eastern Mediterranean is presented at a high spatial resolution. Eastern Mediterranean is affected by various aerosol types (continental, sea, dust and biomass burning particles) and encloses countries with significant socioeconomical changes during the last decades. For the aims of this study, SSR data from satellites (Climate Monitoring Satellite Application Facility - CM SAF) and our ground station in Thessaloniki, a coastal city of ~1 million inhabitants in northern Greece, situated in the heart of Eastern Mediterranean (Eppley Precision pyranometer and Kipp & Zonen CM-11 pyranometer) are used in conjunction with radiative transfer simulations (Santa Barbara DISORT Atmospheric Radiative Transfer - SBDART). The CM SAF dataset used here includes monthly mean SSR observations at a high spatial resolution of 0.03x0.03 degrees for the period 1983-2005. Our ground-based SSR observations span from 1983 until today. SBDART radiative transfer simulations were implemented for a number of spots in the area of study in order to calculate the SSR. High resolution (level-2) aerosol and cloud data from MODIS TERRA and AQUA satellite sensors were used as input, as well as ground-based data from the AERONET. Data from other satellites (Earth Probe TOMS, OMI, etc) and reanalysis projects (ECMWF) were used where needed. The satellite observations, the ground-based measurements and the model estimates are validated against each other. The good agreement

  11. Assessing ground-based counts of nestling bald eagles in northeastern Minnesota

    USGS Publications Warehouse

    Fuller, M.R.; Hatfield, J.S.; Lindquist, E.L.

    1995-01-01

    We present evidence that the bald eagle (Haliaeetus leucocephalus) productivity survey in the Boundary Waters Canoe Area Wilderness of northeastern Minnesota may have underestimated the number of nestlings during 1986-1988. Recommendations are provided to achieve more accurate ground-based counts. By conducting ground-based observations for up to 1 hour/nest, an accurate count of the number of bald eagle nestlings can be obtained. If nests are only observed for up to 30 minutes/nest, an accurate determination of nest success can be made. The effort that managers put into counts should be based on the intended use of the productivity data. If small changes in mean productivity would trigger management action, the less acurate ground-based counts should be conducted with caution. Prior to implementing ground-based counts, a study like ours should estimate bias associated with different survey procedures and the observation time needed to achieve accurate results.

  12. A Methodology for Post Operational Clean Out of a Highly Active Facility Including Solids Behaviour - 12386

    SciTech Connect

    Edmondson, Michael J.; Ward, Tracy R.; Maxwell, Lisa J.

    2012-07-01

    The Highly Active Liquor Evaporation and Storage (HALES) plant at Sellafield handles acidic fission product containing liquor with typical activities of the order of 18x10{sup 9} Bq/ml. A strategy experimental feedback approach has been used to establish a wash regime for the Post Operational Clean Out (POCO) of the oldest storage tanks for this liquor. Two different wash reagents have been identified as being potentially suitable for removal of acid insoluble fission product precipitates. Ammonium carbamate and sodium carbonate yield similar products during the proposed wash cycle. The proposed wash reagents provide dissolution of caesium phosphomolybdate (CPM) and zirconium molybdate (ZM) solid phases but yields a fine, mobile precipitate of metal carbonates from the Highly Active Liquor (HAL) supernate. Addition of nitric acid to the wash effluent can cause CPM to precipitate where there is sufficient caesium and phosphorous available. Where they are not present (from ZM dissolution) the nitric acid addition initially produces a nitrate precipitate which then re-dissolves, along with the metal carbonates, to give a solid-free solution. The different behaviour of the two solids during the wash cycle has led to the proposal for an amended flowsheet. Additional studies on the potential to change the morphology of crystallising ZM have presented opportunities for changing the rheology of ZM sediments through doping with tellurium or particular organic acids. Two different wash reagents have been identified as being potentially suitable for the POCO of HALES Oldside HASTs. AC and SC both yield similar products during the proposed wash cycle. However, the different behaviour of the two principle HAL solids, CPM and ZM, during the wash cycle has led to the proposal for an amended flowsheet. Additional studies on the potential to change the morphology of crystallising ZM have presented opportunities for changing its rheology through doping with tellurium or certain

  13. FORTRAN program for analyzing ground-based radar data: Usage and derivations, version 6.2

    NASA Technical Reports Server (NTRS)

    Haering, Edward A., Jr.; Whitmore, Stephen A.

    1995-01-01

    A postflight FORTRAN program called 'radar' reads and analyzes ground-based radar data. The output includes position, velocity, and acceleration parameters. Air data parameters are also provided if atmospheric characteristics are input. This program can read data from any radar in three formats. Geocentric Cartesian position can also be used as input, which may be from an inertial navigation or Global Positioning System. Options include spike removal, data filtering, and atmospheric refraction corrections. Atmospheric refraction can be corrected using the quick White Sands method or the gradient refraction method, which allows accurate analysis of very low elevation angle and long-range data. Refraction properties are extrapolated from surface conditions, or a measured profile may be input. Velocity is determined by differentiating position. Accelerations are determined by differentiating velocity. This paper describes the algorithms used, gives the operational details, and discusses the limitations and errors of the program. Appendices A through E contain the derivations for these algorithms. These derivations include an improvement in speed to the exact solution for geodetic altitude, an improved algorithm over earlier versions for determining scale height, a truncation algorithm for speeding up the gradient refraction method, and a refinement of the coefficients used in the White Sands method for Edwards AFB, California. Appendix G contains the nomenclature.

  14. Nuclear Rocket Test Facility Decommissioning Including Controlled Explosive Demolition of a Neutron-Activated Shield Wall

    SciTech Connect

    Michael Kruzic

    2007-09-01

    Located in Area 25 of the Nevada Test Site, the Test Cell A Facility was used in the 1960s for the testing of nuclear rocket engines, as part of the Nuclear Rocket Development Program. The facility was decontaminated and decommissioned (D&D) in 2005 using the Streamlined Approach For Environmental Restoration (SAFER) process, under the Federal Facilities Agreement and Consent Order (FFACO). Utilities and process piping were verified void of contents, hazardous materials were removed, concrete with removable contamination decontaminated, large sections mechanically demolished, and the remaining five-foot, five-inch thick radiologically-activated reinforced concrete shield wall demolished using open-air controlled explosive demolition (CED). CED of the shield wall was closely monitored and resulted in no radiological exposure or atmospheric release.

  15. LIPID PEROXIDATION GENERATES BIOLOGICALLY ACTIVE PHOSPHOLIPIDS INCLUDING OXIDATIVELY N-MODIFIED PHOSPHOLIPIDS

    PubMed Central

    Davies, Sean S.; Guo, Lilu

    2014-01-01

    Peroxidation of membranes and lipoproteins converts “inert” phospholipids into a plethora of oxidatively modified phospholipids (oxPL) that can act as signaling molecules. In this review, we will discuss four major classes of oxPL: mildly oxygenated phospholipids, phospholipids with oxidatively truncated acyl chains, phospholipids with cyclized acyl chains, and phospholipids that have been oxidatively N-modified on their headgroups by reactive lipid species. For each class of oxPL we will review the chemical mechanisms of their formation, the evidence for their formation in biological samples, the biological activities and signaling pathways associated with them, and the catabolic pathways for their elimination. We will end by briefly highlighting some of the critical questions that remain about the role of oxPL in physiology and disease. PMID:24704586

  16. Predictors of sprint start speed: the effects of resistive ground-based vs. inclined treadmill training.

    PubMed

    Myer, Gregory D; Ford, Kevin R; Brent, Jensen L; Divine, Jon G; Hewett, Timothy E

    2007-08-01

    There is currently no consensus with regard to the most effective method to train for improved acceleration, or with regard to which kinematic variable provides the greatest opportunity for improvement in this important performance characteristic. The purpose of this study was to determine the effects of resistive ground-based speed training and incline treadmill speed training on speed-related kinematic measures and sprint start speed. The hypothesis tested was that incline treadmill training would improve sprint start time, while the ground-based resistive training would not. Corollary hypotheses were that treadmill training would increase stride frequency and ground-based training would not affect kinematics during the sprint start. Thirty-one high school female soccer players (15.7 +/- 0.5 years) were assigned to either treadmill (n = 17) or ground-based (n = 14) training groups and trained 2 times a week for 6 weeks. The treadmill group utilized incline speed training on a treadmill, while the ground-based group utilized partner band resistance ground-based techniques. Three-dimensional motion analysis was used (4.5 m mark) before and after training to quantify kinematics during the fastest of 3 recorded sprint starts (9.1 m). Both groups decreased average sprint start time from 1.75 +/- 0.12 to 1.68 +/- 0.08 seconds (p < 0.001). Training increased stride frequency (p = 0.030) but not stride length. After training, total vertical pelvic displacement and stride length predicted 62% of the variance in sprint start time for the resistive ground-based group, while stride length and stride frequency accounted for 67% prediction of the variance in sprint start time for the treadmill group. The results of this study indicate that both incline treadmill and resistive ground-based training are effective at improving sprint start speed, although they potentially do so through differing mechanisms.

  17. Evidence of Urban Precipitation Anomalies from Satellite and Ground-Based Measurements

    NASA Technical Reports Server (NTRS)

    Shepherd, J. Marshall; Manyin, M.; Negri, Andrew

    2004-01-01

    Urbanization is one of the extreme cases of land use change. Most of world's population has moved to urban areas. Although currently only 1.2% of the land is considered urban, the spatial coverage and density of cities are expected to rapidly increase in the near future. It is estimated that by the year 2025, 60% of the world's population will live in cities. Human activity in urban environments also alters weather and climate processes. However, our understanding of urbanization on the total Earth-weather-climate system is incomplete. Recent literature continues to provide evidence that anomalies in precipitation exist over and downwind of major cities. Current and future research efforts are actively seeking to verify these literature findings and understand potential cause-effect relationships. The novelty of this study is that it utilizes rainfall data from multiple satellite data sources (e.g. TRMM precipitation radar, TRMM-geosynchronous-rain gauge merged product, and SSM/I) and ground-based measurements to identify spatial anomalies and temporal trends in precipitation for cities around the world. Early results will be presented and placed within the context of weather prediction, climate assessment, and societal applications.

  18. Evidence of Urban Precipitation Anomalies from Satellite and Ground-Based Measurements

    NASA Technical Reports Server (NTRS)

    Shepherd, J. M.; Manyin, M.; Negri, A.

    2004-01-01

    Urbanization is one of the extreme cases of land use change. Most of world s population has moved to urban areas. Although currently only 1.2% of the land is considered urban, the spatial coverage and density of cities are expected to rapidly increase in the near future. It is estimated that by the year 2025,60% of the world s population will live in cities. Human activity in urban environments also alters weather and climate processes. However, our understanding of urbanization on the total Earth-weather-climate system is incomplete. Recent literature continues to provide evidence that anomalies in precipitation exist over and downwind of major cities. Current and future research efforts are actively seeking to verify these literature findings and understand potential cause- effect relationships. The novelty of this study is that it utilizes rainfall data from multiple satellite data sources (e.g. TRMM precipitation radar, TRMM-geosynchronous-rain gauge merged product, and SSM/I) and ground-based measurements to identify spatial anomalies and temporal trends in precipitation for cities around the world. Early results will be presented and placed within the context of weather prediction, climate assessment, and societal applications.

  19. Airborne and ground based CCN spectral characteristics: Inferences from CAIPEEX - 2011

    NASA Astrophysics Data System (ADS)

    Varghese, Mercy; Prabha, Thara V.; Malap, Neelam; Resmi, E. A.; Murugavel, P.; Safai, P. D.; Axisa, Duncan; Pandithurai, G.; Dani, K.

    2016-01-01

    A first time comprehensive study of Cloud Condensation Nuclei (CCN) and associated spectra from both airborne and ground campaigns of the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) conducted over the rain shadow region of Western Ghats during September and October 2011 is illustrated. Observations of CCN spectra during clean, polluted and highly polluted conditions indicated significant differences between airborne and ground observations. Vertical variation of CCN concentration is illustrated from airborne observations in the clean, polluted and highly polluted conditions with different air mass characteristics. The cloud base CCN number concentrations are three times less than that of the surface measurements at different supersaturations. Diurnal variations of the ground based CCN number concentration and activation diameter showed bimodality. Atmospheric mixing in the wet conditions is mainly through mechanical mixing. The dry conditions favored convective mixing and were dominated by more CCN than the wet conditions. New particle formation and growth events have been observed and were found more often on days with convective mixing. The average critical activation diameter (at 0.6% SS) observed at the ground is approximately 60 nm and availability of a large number of particles below this limit was due to the new particle formation. Observations give convincing evidence that the precipitable water and liquid water path is inversely proportional to surface CCN number concentration, and this relationship is largely dictated by the meteorological conditions.

  20. Design of a high-lift experiment in water including active flow control

    NASA Astrophysics Data System (ADS)

    Beutel, T.; Sattler, S.; El Sayed, Y.; Schwerter, M.; Zander, M.; Büttgenbach, S.; Leester-Schädel, M.; Radespiel, R.; Sinapius, M.; Wierach, P.

    2014-07-01

    This paper describes the structural design of an active flow-control experiment. The aim of the experiment is to investigate the increase in efficiency of an internally blown Coanda flap using unsteady blowing. The system uses tailor-made microelectromechanical (MEMS) pressure sensors to determine the state of the oncoming flow and an actuated lip to regulate the mass flow and velocity of a stream near a wall over the internally blown flap. Sensors and actuators are integrated into a highly loaded system that is extremely compact. The sensors are connected to a bus system that feeds the data into a real-time control system. The piezoelectric actuators using the d 33 effect at a comparable low voltage of 120 V are integrated into a lip that controls the blowout slot height. The system is designed for closed-loop control that efficiently avoids flow separation on the Coanda flap. The setup is designed for water-tunnel experiments in order to reduce the free-stream velocity and the system’s control frequency by a factor of 10 compared with that in air. This paper outlines the function and verification of the system’s main components and their development.

  1. Fatty acid-releasing activities in Sinorhizobium meliloti include unusual diacylglycerol lipase

    PubMed Central

    Sahonero-Canavesi, Diana X.; Sohlenkamp, Christian; Sandoval-Calderón, Mario; Lamsa, Anne; Pogliano, Kit; López-Lara, Isabel M.; Geiger, Otto

    2016-01-01

    Summary Phospholipids are well known for their membrane forming properties and thereby delimit any cell from the exterior world. In addition, membrane phospholipids can act as precursors for signals and other biomolecules during their turnover. Little is known about phospholipid signalling, turnover and remodelling in bacteria. Recently, we showed that a FadD-deficient mutant of Sinorhizobium meliloti, unable to convert free fatty acids to their coenzyme A derivatives, accumulates free fatty acids during the stationary phase of growth. Enzymatic activities responsible for the generation of these free fatty acids were unknown in rhizobia. Searching the genome of S. meliloti, we identified a potential lysophospholipase (SMc04041) and two predicted patatin-like phospholipases A (SMc00930, SMc01003). Although SMc00930 as well as SMc01003 contribute to the release of free fatty acids in S. meliloti, neither one can use phospholipids as substrates. Here we show that SMc01003 converts diacylglycerol to monoacylglycerol and a fatty acid, and that monoacylglycerol can be further degraded by SMc01003 to another fatty acid and glycerol. A SMc01003-deficient mutant of S. meliloti transiently accumulates diacylglycerol, suggesting that SMc01003 also acts as diacylglycerol lipase (DglA) in its native background. Expression of the DglA lipase in Escherichia coli causes lysis of cells in stationary phase of growth. PMID:25711932

  2. Fatty acid-releasing activities in Sinorhizobium meliloti include unusual diacylglycerol lipase.

    PubMed

    Sahonero-Canavesi, Diana X; Sohlenkamp, Christian; Sandoval-Calderón, Mario; Lamsa, Anne; Pogliano, Kit; López-Lara, Isabel M; Geiger, Otto

    2015-09-01

    Phospholipids are well known for their membrane-forming properties and thereby delimit any cell from the exterior world. In addition, membrane phospholipids can act as precursors for signals and other biomolecules during their turnover. Little is known about phospholipid signalling, turnover and remodelling in bacteria. Recently, we showed that a FadD-deficient mutant of Sinorhizobium meliloti, unable to convert free fatty acids to their coenzyme A derivatives, accumulates free fatty acids during the stationary phase of growth. Enzymatic activities responsible for the generation of these free fatty acids were unknown in rhizobia. Searching the genome of S. meliloti, we identified a potential lysophospholipase (SMc04041) and two predicted patatin-like phospholipases A (SMc00930, SMc01003). Although SMc00930 as well as SMc01003 contribute to the release of free fatty acids in S. meliloti, neither one can use phospholipids as substrates. Here we show that SMc01003 converts diacylglycerol to monoacylglycerol and a fatty acid, and that monoacylglycerol can be further degraded by SMc01003 to another fatty acid and glycerol. A SMc01003-deficient mutant of S. meliloti transiently accumulates diacylglycerol, suggesting that SMc01003 also acts as diacylglycerol lipase (DglA) in its native background. Expression of the DglA lipase in Escherichia coli causes lysis of cells in stationary phase of growth.

  3. Modeling the development of biofilm density including active bacteria, inert biomass, and extracellular polymeric substances.

    PubMed

    Laspidou, Chrysi S; Rittmann, Bruce E

    2004-01-01

    We present the unified multi-component cellular automaton (UMCCA) model, which predicts quantitatively the development of the biofilm's composite density for three biofilm components: active bacteria, inert or dead biomass, and extracellular polymeric substances. The model also describes the concentrations of three soluble organic components (soluble substrate and two types of soluble microbial products) and oxygen. The UMCCA model is a hybrid discrete-differential mathematical model and introduces the novel feature of biofilm consolidation. Our hypothesis is that the fluid over the biofilm creates pressures and vibrations that cause the biofilm to consolidate, or pack itself to a higher density over time. Each biofilm compartment in the model output consolidates to a different degree that depends on the age of its biomass. The UMCCA model also adds a cellular automaton algorithm that identifies the path of least resistance and directly moves excess biomass along that path, thereby ensuring that the excess biomass is distributed efficiently. A companion paper illustrates the trends that the UMCCA model is able to represent and shows a comparison with experimental results. PMID:15276752

  4. Ozone control of biological activity during Earth's history, including the KT catastrophe

    NASA Technical Reports Server (NTRS)

    Sheldon, W. R.

    1994-01-01

    There have been brief periods since the beginning of the Cambrian some 600 m.y. ago when mass extinctions destroyed a significant fraction of living species. The most widely studied of these events is the catastrophe at the KT boundary that ended the long dominance of the dinosaurs. In addition to mass extinctions, there is another profound discontinuity in the history of Earth's biota, the explosion of life at the end of the Precambrian era which is an episode that is not explained well at all. For some 3 b.y. before the Cambrian, life had been present on Earth, but maintained a low level of activity which is an aspect of the biota that is puzzling, especially during the last two-thirds of that period. During the last 2 b.y. before the Cambrian, conditions at the Earth's surface were suitable for a burgeoning of the biota, according to most criteria: the oceans neither boiled nor were fozen solid during this time, and the atmosphere contained sufficient O for the development of animals. The purpose of this paper is to suggest that mass extinctions and the lackluster behavior of the Precambrian biota share a common cause: an inadequate amount of ozone in the atmosphere.

  5. Radio Properties of Low Redshift Broad Line Active Galactic Nuclei Including Multiple Component Radio Sources

    NASA Astrophysics Data System (ADS)

    Rafter, Stephen E.

    2010-01-01

    We present results on the radio properties of a low redshift (z < 0.35) sample of 8434 broad line active galactic nuclei (AGNs) from the Sloan Digital Sky Survey after correlating the optical sources with radio sources in the Faint Images of the Radio Sky at Twenty-Centimeters survey. We find that 10% of our sample has radio emission < 4" away from the optical counterpart (core-only sources), and 1% has significant extended emission that must be taken into account when calculating the total radio luminosity (multi-component sources). Association of the extended radio emission is established by the proximity to the optical source, physical connection of jets and lobes, or large scale symmetry like in classic FRIIs. From these data we find an FRI/FRII luminosity dividing line like that found by Fanaroff & Riley (1974), where we use our core-only sources as proxies for FRIs, and our multi-component sources for the FRIIs. We find a bimodal distribution for the radio loudness (R = L(radio)/L(opt)) where the lower radio luminosity core-only sources appear as a population separate from the multi-component extended sources, compared with no evidence for bimodality when just the core-only sources are used. We also find that a log(R) value of 1.75 is well suited to separate the FRIs from the FRIIs, and that the R bimodality seen here is really a manifestation of the FRI/FRII break originally found by Fanaroff & Riley (1974). We find modest trends in the radio loud fraction as a function of Eddington ratio and black hole mass, where the fraction of RL AGNs decreases with increasing Eddington ratio, and increases when the black hole mass is above 2 x 108 solar masses.

  6. Comparing ECMWF UV Processor and Aerosol Scheme with Ground-Based Measurements

    NASA Astrophysics Data System (ADS)

    Cesnulyte, V.; Lindfors, A. V.; Pitkänen, M. R. A.; Lehtinen, K. E.; Morcrette, J. J.; Arola, A. T.

    2014-12-01

    The ECMWF (European Centre for Medium-Range Weather Forecasts) system offers an alternative approach to provide global UV data products which can support environmental assessments of UV radiation, biological and photochemical impact studies, and to contribute to the global climatology of UV radiation. The ECMWF model includes the effect of aerosols as a part of its radiation transfer calculations. During the first steps of the development of the UV processor, an aerosol climatology was used. In the latest version, however, prognostic aerosols have been coupled with the UV processor which, as a result, provides information about the global UV radiation and can be an alternative to satellite observations. The aim of this study is to evaluate the ECMWF UV/aerosol optical depth (AOD) model against ground-based measurements and further develop the UV Processor. The ECMWF shortwave radiative transfer scheme provides the UV radiation at the surface for wavelengths between 280 and 400nm. However, for this analysis, the wavelength ranges 290-320 (UVB) and 320-340 (UVA) were used. This is the first time when a global model such as the ECMWF is evaluated for the performance of AOD at a UV wavelength. The results show that the MACC system generally provides a good representation of the AOD on a monthly basis, showing a realistic seasonal cycle. The model is mostly able to capture major dust load events and also the peak months of biomass burning correctly. When comparing hourly AOD values, the model-measurement agreement is better for biomass burning (CC = 0.90) and dust sites (CC = 0.77) than for urban sites (CC = 0.70). All sites included in the study show a relative mean bias at 340 nm smaller than that at 500 nm, indicating a strong wavelength-dependence in the performance of the AOD in the MACC system. Validating the UV Processor, in all the UV validation sites, the model-measurement ratio decreased with increasing solar zenith angle (SZA). This effect is larger for UVB

  7. BENEFITS OF GROUND-BASED PHOTOMETRIC FOLLOW-UP FOR TRANSITING EXTRASOLAR PLANETS DISCOVERED WITH KEPLER AND CoRoT

    SciTech Connect

    Colon, Knicole D.; Ford, Eric B.

    2009-09-20

    Currently, over 40 transiting planets have been discovered by ground-based photometric surveys, and space-based missions such as Kepler and CoRoT are expected to detect hundreds more. Follow-up photometric observations from the ground will play an important role in constraining both orbital and physical parameters for newly discovered planets, especially those with small radii (R{sub p} {approx}< 4R{sub +}) and/or intermediate-to-long orbital periods (P{approx}> 30 days). Here, we simulate transit light curves (LCs) from Kepler-like photometry and ground-based observations in the near-infrared (NIR) to determine how jointly modeling space-based and ground-based LCs can improve measurements of the transit duration and planet-star radius ratio. We find that adding observations of at least one ground-based transit to space-based observations can significantly improve the accuracy for measuring the transit duration and planet-star radius ratio of small planets (R{sub p} {approx}< 4R{sub +}) in long-period ({approx}1 year) orbits, largely thanks to the reduced effect of limb darkening in the NIR. We also demonstrate that multiple ground-based observations are needed to gain a substantial improvement in the measurement accuracy for small planets with short orbital periods ({approx}3 days). Finally, we consider the role that higher ground-based precisions will play in constraining parameter measurements for typical Kepler targets. Our results can help inform the priorities of transit follow-up programs (including both primary and secondary transit of planets discovered with Kepler and CoRoT), leading to improved constraints for transit durations, planet sizes, and orbital eccentricities.

  8. Ground-based Observation of Post-Hayabusa Mission Targets

    NASA Astrophysics Data System (ADS)

    Abe, M.; Kitazato, K.; Sarugaku, Y.; Kawakatsu, Y.; Kinoshita, D.

    2007-03-01

    In 2006, we have observed 14 near-Earth asteroids as the candidate object of the post-Hayabusa mission, using Kiso and Lulin Observatory. Including our previous observation, we found that five asteroids are classified in C-type Group.

  9. A Methodology for Evaluating the Fidelity of Ground-Based Flight Simulators

    NASA Technical Reports Server (NTRS)

    Zeyada, Y.; Hess, R. A.

    1999-01-01

    An analytical and experimental investigation was undertaken to model the manner in which pilots perceive and utilize visual, proprioceptive, and vestibular cues in a ground-based flight simulator. The study was part of a larger research effort which has the creation of a methodology for determining flight simulator fidelity requirements as its ultimate goal. The study utilized a closed-loop feedback structure of the pilot/simulator system which included the pilot, the cockpit inceptor, the dynamics of the simulated vehicle and the motion system. With the exception of time delays which accrued in visual scene production in the simulator, visual scene effects were not included in this study. The NASA Ames Vertical Motion Simulator was used in a simple, single-degree of freedom rotorcraft bob-up/down maneuver. Pilot/vehicle analysis and fuzzy-inference identification were employed to study the changes in fidelity which occurred as the characteristics of the motion system were varied over five configurations. The data from three of the five pilots that participated in the experimental study were analyzed in the fuzzy-inference identification. Results indicate that both the analytical pilot/vehicle analysis and the fuzzy-inference identification can be used to reflect changes in simulator fidelity for the task examined.

  10. AQUARIUS, the next generation mid-IR detector for ground-based astronomy

    NASA Astrophysics Data System (ADS)

    Ives, Derek; Finger, Gert; Jakob, Gerd; Eschbaumer, Siegfried; Mehrgan, Leander; Meyer, Manfred; Steigmeier, Joerg

    2012-07-01

    ESO has recently funded the development of the AQUARIUS detector at Raytheon Vision Systems, a new mega-pixel Si:As Impurity Band Conduction array for use in ground based astronomical applications at wavelengths between 3 - 28 μm. The array has been designed to have low noise, low dark current, switchable gain and be read out at very high frame rates. It has 64 individual outputs capable of pixel read rates of 3MHz, implying continuous data-rates in excess of 300 Mbytes/second. It is scheduled for deployment into the VISIR instrument at the VLT in 2012, for next generation VLTI instruments and base-lined for METIS, the mid-IR candidate instrument for the E-ELT. A new mid-IR test facility has been developed for AQUARIUS detector development which includes a low thermal background cryostat, high speed cryogenic pre-amplification and high speed data acquisition and detector operation at 5K. We report on all the major performance aspects of this new detector including conversion gain, read noise, dark generation rate, linearity, well capacity, pixel operability, low frequency noise, persistence and electrical cross-talk. We describe the many possible readout modes of this detector and their application. We also report on external issues with the operation of these detectors at such low temperatures. Finally we report on the electronic developments required to operate such a detector at the required high data rates and in a typical mid-IR instrument.

  11. A New Network Modeling Tool for the Ground-based Nuclear Explosion Monitoring Community

    NASA Astrophysics Data System (ADS)

    Merchant, B. J.; Chael, E. P.; Young, C. J.

    2013-12-01

    Network simulations have long been used to assess the performance of monitoring networks to detect events for such purposes as planning station deployments and network resilience to outages. The standard tool has been the SAIC-developed NetSim package. With correct parameters, NetSim can produce useful simulations; however, the package has several shortcomings: an older language (FORTRAN), an emphasis on seismic monitoring with limited support for other technologies, limited documentation, and a limited parameter set. Thus, we are developing NetMOD (Network Monitoring for Optimal Detection), a Java-based tool designed to assess the performance of ground-based networks. NetMOD's advantages include: coded in a modern language that is multi-platform, utilizes modern computing performance (e.g. multi-core processors), incorporates monitoring technologies other than seismic, and includes a well-validated default parameter set for the IMS stations. NetMOD is designed to be extendable through a plugin infrastructure, so new phenomenological models can be added. Development of the Seismic Detection Plugin is being pursued first. Seismic location and infrasound and hydroacoustic detection plugins will follow. By making NetMOD an open-release package, it can hopefully provide a common tool that the monitoring community can use to produce assessments of monitoring networks and to verify assessments made by others.

  12. Satellite to Ground-based LIDAR Comparisons using MPLNET Data Products

    NASA Technical Reports Server (NTRS)

    Berkoff, T.A.; Belcher, L.; Campbell, J.; Spinhirne, J.; Welton, E. J.

    2007-01-01

    The Micro-Pulse Lidar Network (MPLNET) is a network of ground-based lidar systems that provide continuous long-term observations of aerosol and cloud properties at approximately 10 different locations around the globe. Each site in the network uses an elastic scattering lidar co-located with a sunphotometer to provide data products of aerosol optical physical properties. Data products from sites are available on a next-day basis from the MPLNET website. Expansion of the network is based on partnering with research groups interested in joining MPLNET. Results have contributed to a variety of studies including aerosol transport studies and satellite calibration and validation efforts. One of the key motivations for MPLNET is to contribute towards the calibration and validation of satellite-based lidars such as GLAS/ICESAT and CALIPSO. MPLNET is able to provide comparison to several of the key aerosol and cloud CALIPSO data products including: layer height and thickness, optical depth, backscatter and extinction profiles, and the extinction-to-backscatter ratio.

  13. Investigation of otolith responses using ground based vestibular research facility

    NASA Technical Reports Server (NTRS)

    Correia, Manning J.; TABARACCI

    1989-01-01

    The general goal was to examine tilt sensitivity of horizontal semicircular canal afferents. Computer programs were tested which controlled the short axis centrifuge at the Vestibular Research Facility, acquired action potentials and produced data reduction analyses including histograms and gain and phase calculations. A pre-amplifier was also developed for the acquisition of action potentials. The data were gathered that can be used to contribute toward the understanding of the tilt sensitivity of semicircular canal afferents in the unanesthetized gerbil preparation.

  14. Ground-based astronomical instrument for planetary protection

    NASA Astrophysics Data System (ADS)

    Kendrick, Richard L.; Bennett, Dave; Bold, Matthew

    2014-07-01

    Planetary protection consists of the measurement and characterization of near-earth objects including earth threatening asteroids and earth orbiting debris. The Lockheed Martin STAR Labs in Palo Alto California is developing new astronomical instruments for use in planetary protection. The observation of asteroids is standard for astronomical facilities and there are available instruments designed with this specific science mission in mind. Orbital debris observation and characterization has a somewhat different set of requirements and includes large fields of view with simultaneous spectro-polarimetric data on multiple closely spaced objects. Orbital debris is comprised of spent rocket bodies, rocket fairing covers, paint chips, various satellite components, debris from satellite collisions and explosions and nonoperational satellites. The debris is present in all orbital planes from Low Earth orbit out to the geosynchronous graveyard orbit. We concentrate our effort on the geosynchronous and nearby orbits. This is because typical groundbased astronomical telescopes are built to track at sidereal rates and not at the 1 degree per second rates that are required to track low earth orbiting objects. The orbital debris materials include aluminum, mylar, solar cell materials, composite matrix material and other materials that are used in the fabrication of satellites and launch vehicles. These materials typically have spectral features in different wavebands than asteroids which are mostly composed of materials with molecular absorption bands such as in H2O. This will drive an orbital debris material identification instrument to wavebands and resolutions that are typically not used in asteroid observations.

  15. Strategies for Ground Based Testing of Manned Lunar Surface Systems

    NASA Technical Reports Server (NTRS)

    Beyer, Jeff; Peacock, Mike; Gill, Tracy

    2009-01-01

    Integrated testing (such as Multi-Element Integrated Test (MEIT)) is critical to reducing risks and minimizing problems encountered during assembly, activation, and on-orbit operation of large, complex manned spacecraft. Provides the best implementation of "Test Like You Fly:. Planning for integrated testing needs to begin at the earliest stages of Program definition. Program leadership needs to fully understand and buy in to what integrated testing is and why it needs to be performed. As Program evolves and design and schedules mature, continually look for suitable opportunities to perform testing where enough components are together in one place at one time. The benefits to be gained are well worth the costs.

  16. Ground-based tests of JEM-EUSO components at the Telescope Array site, "EUSO-TA"

    NASA Astrophysics Data System (ADS)

    Adams, J. H.; Ahmad, S.; Albert, J.-N.; Allard, D.; Anchordoqui, L.; Andreev, V.; Anzalone, A.; Arai, Y.; Asano, K.; Ave Pernas, M.; Baragatti, P.; Barrillon, P.; Batsch, T.; Bayer, J.; Bechini, R.; Belenguer, T.; Bellotti, R.; Belov, K.; Berlind, A. A.; Bertaina, M.; Biermann, P. L.; Biktemerova, S.; Blaksley, C.; Blanc, N.; Błȩcki, J.; Blin-Bondil, S.; Blümer, J.; Bobik, P.; Bogomilov, M.; Bonamente, M.; Briggs, M. S.; Briz, S.; Bruno, A.; Cafagna, F.; Campana, D.; Capdevielle, J.-N.; Caruso, R.; Casolino, M.; Cassardo, C.; Castellinic, G.; Catalano, C.; Catalano, G.; Cellino, A.; Chikawa, M.; Christl, M. J.; Cline, D.; Connaughton, V.; Conti, L.; Cordero, G.; Crawford, H. J.; Cremonini, R.; Csorna, S.; Dagoret-Campagne, S.; de Castro, A. J.; De Donato, C.; de la Taille, C.; De Santis, C.; del Peral, L.; Dell'Oro, A.; De Simone, N.; Di Martino, M.; Distratis, G.; Dulucq, F.; Dupieux, M.; Ebersoldt, A.; Ebisuzaki, T.; Engel, R.; Falk, S.; Fang, K.; Fenu, F.; Fernández-Gómez, I.; Ferrarese, S.; Finco, D.; Flamini, M.; Fornaro, C.; Franceschi, A.; Fujimoto, J.; Fukushima, M.; Galeotti, P.; Garipov, G.; Geary, J.; Gelmini, G.; Giraudo, G.; Gonchar, M.; González Alvarado, C.; Gorodetzky, P.; Guarino, F.; Guzmán, A.; Hachisu, Y.; Harlov, B.; Haungs, A.; Hernández Carretero, J.; Higashide, K.; Ikeda, D.; Ikeda, H.; Inoue, N.; Inoue, S.; Insolia, A.; Isgrò, F.; Itow, Y.; Joven, E.; Judd, E. G.; Jung, A.; Kajino, F.; Kajino, T.; Kaneko, I.; Karadzhov, Y.; Karczmarczyk, J.; Karus, M.; Katahira, K.; Kawai, K.; Kawasaki, Y.; Keilhauer, B.; Khrenov, B. A.; Kim, J.-S.; Kim, S.-W.; Kim, S.-W.; Kleifges, M.; Klimov, P. A.; Kolev, D.; Kreykenbohm, I.; Kudela, K.; Kurihara, Y.; Kusenko, A.; Kuznetsov, E.; Lacombe, M.; Lachaud, C.; Lee, J.; Licandro, J.; Lim, H.; López, F.; Maccarone, M. C.; Mannheim, K.; Maravilla, D.; Marcelli, L.; Marini, A.; Martinez, O.; Masciantonio, G.; Mase, K.; Matev, R.; Medina-Tanco, G.; Mernik, T.; Miyamoto, H.; Miyazaki, Y.; Mizumoto, Y.; Modestino, G.; Monaco, A.; Monnier-Ragaigne, D.; Morales de los Ríos, J. A.; Moretto, C.; Morozenko, V. S.; Mot, B.; Murakami, T.; Murakami, M. Nagano; Nagata, M.; Nagataki, S.; Nakamura, T.; Napolitano, T.; Naumov, D.; Nava, R.; Neronov, A.; Nomoto, K.; Nonaka, T.; Ogawa, T.; Ogio, S.; Ohmori, H.; Olinto, A. V.; Orleański, P.; Osteria, G.; Panasyuk, M. I.; Parizot, E.; Park, I. H.; Park, H. W.; Pastircak, B.; Patzak, T.; Paul, T.; Pennypacker, C.; Perez Cano, S.; Peter, T.; Picozza, P.; Pierog, T.; Piotrowski, L. W.; Piraino, S.; Plebaniak, Z.; Pollini, A.; Prat, P.; Prévôt, G.; Prieto, H.; Putis, M.; Reardon, P.; Reyes, M.; Ricci, M.; Rodríguez, I.; Rodríguez Frías, M. D.; Ronga, F.; Roth, M.; Rothkaehl, H.; Roudil, G.; Rusinov, I.; Rybczyński, M.; Sabau, M. D.; Sáez-Cano, G.; Sagawa, H.; Saito, A.; Sakaki, N.; Sakata, M.; Salazar, H.; Sánchez, S.; Santangelo, A.; Santiago Crúz, L.; Sanz Palomino, M.; Saprykin, O.; Sarazin, F.; Sato, H.; Sato, M.; Schanz, T.; Schieler, H.; Scotti, V.; Segreto, A.; Selmane, S.; Semikoz, D.; Serra, M.; Sharakin, S.; Shibata, T.; Shimizu, H. M.; Shinozaki, K.; Shirahama, T.; Siemieniec-Oziȩbło, G.; Silva López, H. H.; Sledd, J.; Słomińska, K.; Sobey, A.; Sugiyama, T.; Supanitsky, D.; Suzuki, M.; Szabelska, B.; Szabelski, J.; Tajima, F.; Tajima, N.; Tajima, T.; Takahashi, Y.; Takami, H.; Takeda, M.; Takizawa, Y.; Tenzer, C.; Tibolla, O.; Tkachev, L.; Tokuno, H.; Tomida, T.; Tone, N.; Toscano, S.; Trillaud, F.; Tsenov, R.; Tsunesada, Y.; Tsuno, K.; Tymieniecka, T.; Uchihori, Y.; Unger, M.; Vaduvescu, O.; Valdés-Galicia, J. F.; Vallania, P.; Valore, L.; Vankova, G.; Vigorito, C.; Villaseñor, L.; von Ballmoos, P.; Wada, S.; Watanabe, J.; Watanabe, S.; Watts, J.; Weber, M.; Weiler, T. J.; Wibig, T.; Wiencke, L.; Wille, M.; Wilms, J.; Włodarczyk, Z.; Yamamoto, T.; Yamamoto, Y.; Yang, J.; Yano, H.; Yashin, I. V.; Yonetoku, D.; Yoshida, K.; Yoshida, S.; Young, R.; Zotov, M. Yu.; Zuccaro Marchi, A.

    2015-11-01

    We are conducting tests of optical and electronics components of JEMEUSO at the Telescope Array site in Utah with a ground-based "EUSO-TA" detector. The tests will include an engineering validation of the detector, cross-calibration of EUSO-TA with the TA fluorescence detector and observations of air shower events. Also, the proximity of the TA's Electron Light Source will allow for convenient use of this calibration device. In this paper, we report initial results obtained with the EUSO-TA telescope.

  17. Should Physical Activity Be Included in Nutrition Education? A Comparison of Nutrition Outcomes with and without In-Class Activities

    ERIC Educational Resources Information Center

    Palmer-Keenan, Debra M.; Corda, Kirsten

    2014-01-01

    Limited-resource adults' dietary intakes and nutrition behaviors improve as a result of Expanded Food and Nutrition Education Program (EFNEP)/Supplemental Nutrition Assistance Program Education (SNAP-Ed) participation; however, physical activity education is needed for improved health. The experimental study reported here assessed if spending…

  18. Comparison of glyoxal, BrO, and IO vertical profiles derived from both ground-based and airborne MAX-DOAS measurements

    NASA Astrophysics Data System (ADS)

    Coburn, Sean; Volkamer, Rainer; Baidar, Sunil; Dix, Barbara; Koenig, Theodore; Ortega, Ivan; Sinreich, Roman; van Roozendael, Michel; Hendrick, Francois; Kinnison, Doug

    2015-04-01

    The information content of ground-based MAX-DOAS retrievals is assessed by collocated aircraft measurements for a ship MAX-DOAS setup over the Eastern tropical Pacific Ocean (TORERO RF17), and a mountain-top MAX-DOAS setup at Mauna Loa Observatory, Hawaii (CONTRAST RF17). During both case studies the CU airborne MAX-DOAS (AMAX-DOAS) instrument aboard the NSF/NCAR GV aircraft measured profiles of glyoxal, BrO, and IO with 12-20 degrees of freedom and up to 500 m vertical resolution. The TORERO field campaign took place in 2012, while CONTRAST in 2014; both campaigns covered the months of January and February. Additional measurements aboard the aircraft helped to provide information/validation of the AMAX-DOAS derived profiles, such as in-situ water vapor from the Vertical-Cavity Surface-Emitting Laser hygrometer (VCSEL), in-situ hydrocarbon measurements from the Trace Organic Gas Analyzer (TOGA), and aerosol information constrained by the Ultra High Sensitivity Aerosol Spectrometer (UHSAS). The AMAX-DOAS profiles are compared with ground-based MAX-DOAS inversions. The latter explores the effect of using either the measured differential slant column density (dSCD) or SCD as input to the optimal estimation inversion, where SCD = dSCD + SCD_ref. SCD_ref is the residual column amount of the trace gas contained within the reference spectrum. For the AMAX-DOAS data, the values of SCD_ref were actively minimized, while SCD_ref is usually unknown for ground-based MAX-DOAS retrievals. In absence of independent measurements to constrain SCD_ref, the current state-of-the-art with ground-based MAX-DOAS applications is to use dSCDs as input to the inversion. Here we assess the effect of uncertain SCD_ref for ground-based MAX-DOAS profiles in form of a sensitivity study. Additionally for the ground-based data, different methods are compared for the determination of SCD_ref: 1) the collocated aircraft profiles described above present the opportunity to forward calculate the SCD

  19. Ground-Based Investigations with the Cryogenic Hydrogen Maser

    NASA Technical Reports Server (NTRS)

    Walsworth, Ronald L.; Mattison, Edward; Vessot, Robert F. C.

    2001-01-01

    The room temperature hydrogen maser is an active atomic oscillator used as a high-frequency-stability local oscillator for radio astronomy, metrology, and spacecraft navigation, and in tests of fundamental physics. The cryogenic hydrogen maser (CHM) operates at 0.5 K, employing superfluid helium-coated walls to store the masing hydrogen atoms. We are investigating whether the CHM may provide better frequency stability than the room temperature hydrogen maser: one to three orders of magnitude improvement may be possible because of greatly reduced thermal noise and larger signal power. Exceptional frequency stability will be required for spacecraft tracking in future deep-space missions, for space-based tests of relativity and gravitation, and for local (i.e., flywheel) oscillators used with absolute frequency standards such as laser-cooled atomic fountains and linear ion traps. These new devices are passive high-resolution frequency discriminators. Alone, they cannot function as superior atomic clocks; their effective operation depends on being integrated with an active local oscillator with excellent short term stability - such as that possible with the CHM.

  20. Ground-based VLBI observations of orbiters and landers.

    NASA Astrophysics Data System (ADS)

    Cimo, G.; Duev, D.; Molera Calves, G.; Bocanegra Bohamon, T.; Pogrebenko, S.; Gurvits, L.

    2015-10-01

    Phase referencing near-field VLBI observations and radial Doppler measurements of spacecraft provide ultra-precise estimates of spacecraft state vectors. These measurements can be used for a variety of scientific applications, both fundamental and applied, including planetary science, improvement of ephemerides, ultra-precise celestial mechanics of planetary systems, gravimetry, spacecraft orbit determination, and fundamental physics. Precise determination of the lateral position of spacecraft on the celestial sphere is the main deliverable of the Planetary Radio Interferometry and Doppler Experiment (PRIDE). This technique is complementary to radio science experiments and addresses those areas of spacecraft mission science objectives that require accurate estimation of spacecraft state vector.

  1. Cardiovascular responses to weightlessness and ground-based simulations

    NASA Technical Reports Server (NTRS)

    Sandler, H.

    1982-01-01

    Mission experience, from NASA and Soviet programs, on human cardiovascular responses to weightlessness, and the ability of bed rest studies to simulate these are discussed. In-flight effects include fluid shift to the upper body, decreased heart size, bone demineralization, orthostatic intolerance, and loss of exercise tolerance. All the cardiovascular changes that occur with weightlessness also occur with prolonged bed rest. They are most manifest when subjects stand suddenly, or undergo tilting or lower body negative pressure. The mechanisms which control these responses, e.g., the role of the central nervous system, are unclear.

  2. On the weighting of SABER temperature profiles for comparison with ground based hydroxyl rotational temperatures.

    NASA Astrophysics Data System (ADS)

    French, William; Mulligan, Frank

    2010-05-01

    Kinetic temperature profiles are retrieved from limb-emission radiance measurements of CO2 at 15 and 4.3 um by the SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) instrument on the TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics) satellite. Profiles extend from about 20-120km and measurements are available since the spacecraft launch in Dec-2001. Hydroxyl (6-2) band rotational temperatures are measured using a ground-based scanning spectrometer at Davis station, Antarctica (68°S, 78°E). Measurements are available each year since 1995 on nights between early February and late October, when the sun is more than 6° below the horizon. In order to compare temperatures from these two instruments we must derive hydroxyl layer equivalent temperatures for the SABER profiles using a weighting function which represents the hydroxyl layer profile. In this study, we examine a number of different weighting profiles to determine the best equivalent to hydroxyl nightly average temperatures at Davis. These profiles include (1) the customary Gaussian peaked at 87km and width 8km [Baker and Stair, 1988 :Physica Scripta. 37 611-622], (2) the layer profile derived from WINDIIUARS hydroxyl height profiles [She and Lowe, 1998 :JASTP 60, 1573-1583], (3) layer profiles derived from the hydroxyl volume emission rate (VER) from the SABER OH-B channel at 1.6um, which contains the Meinel OH(4-2) and OH(5-3) bands and (4) a Gaussian fitted to the SABER hydroxyl VER peak. The comparison is made with approximately 2500 SABER retrievals from overpasses within 500km of Davis station, and with solar zenith angle >97°, which have coincident hydroxyl temperature measurements over the 8 winters between 2002 and 2009. Due to the satellite 60 day yaw cycle the sampling over Davis has occurred in approximately the same three time intervals each year; between days 75-140, 196-262 and 323-014, however the latter interval is entirely rejected on the solar zenith

  3. Coupling between tsunamis and ionosphere: ground-based and space-based observation opportunities

    NASA Astrophysics Data System (ADS)

    Coisson, Pierdavide; Makela, Jonathan J.; Occhipinti, Giovanni; Astafyeva, Elvira; alam Kherani, Esfhan; Lognonne, Philippe

    2012-07-01

    Large scale phenomena as tsunamis propagating through the ocean excite gravity waves that can reach ionospheric heights. The coupling between the ground/ocean and the atmosphere up to the ionosphere opens the possibility to observe in the upper atmosphere the effects of the propagation of tsunamis. During all recent major tsunami events ionospheric waves have been observed by ground GPS networks, satellite altimeters and, recently, also by an airglow imager. During the tsunami event of 11 March 2011 an all-sky camera in Hawaii observes the Internal Gravity Waves (IGW) during about one-and-a-half hours before the arrival of the, while it was crossing the Pacific Ocean in that region. Collocated ionospheric measurements were also done with GNSS sounding and Jason satellite. We present results of assessment studies of ground-based and space-based ionospheric remote sensing for tsunami propagation monitoring. We analyze the cases of airglow imager, Over-The-Horizon (OTH) radar, GPS, radio occultation and GNSS reflectometry. We describe modeling results of IGW excited by a realistic tsunami propagation model through the ocean near Hawaii. The model includes the propagation of the gravity wave in the atmosphere, the coupling between neutral and charged particles in the ionosphere and the production of the airglow emission at 630.0 nm. Synthetic all-sky images are calculated by integration of the emission along rays from the camera location to though the airglow layer. Additional ground-based observations could be provided by (OTH) radars, which operate in High Frequency (HF) band and can be used to monitor the bottomside ionosphere. Synthetic radar measurements computed using HF numerical ray-tracing confirm the possibility to detect IGW excited by tsunamis. The large coverage of OTH radar and its sensitivity to low-altitude plasma anomalies provides a wide range of observation. Additionally, we analyze the capabilities of space-based radio occultation and GNSS

  4. Satellite-Model-Ground-based Inter-Comparisons (WG-3)

    NASA Technical Reports Server (NTRS)

    Kahn, Ralph A.

    2014-01-01

    AERO-SAT is an international consortium of experts on aerosol remote sensing from ground and space. This initiative was established in 2013 (1) to accelerate the exchange of ideas and concepts and (2) to elevate the capabilities of satellite sensorsretrieval (aerosol) products, which are needed to constrain aerosol processing in and assist in evaluations of global modeling. The main goal of the meeting is to substantiate and invigorate the five AEROSAT working groups. On each of those five topics dedicated working groups are building up and will report on their initial activities followed by further related presentations and ample time for discussions. Organizers of the meeting held September 27-28, 2014 would like to post the presentations to a website.

  5. Development of an oregano-based ointment with anti-microbial activity including activity against methicillin-resistant Staphlococcus aureus.

    PubMed

    Eng, William; Norman, Robert

    2010-04-01

    Increasing antibiotic resistance has prompted a search for new compounds with anti-microbial activity. In the authors' previous study, oregano extract was identified as one of the most potent anti-microbial compounds. The disk diffusion method was employed to assess the degree of inhibition against various microorganisms, and the bacteriostatic or bactericidal mechanism of action. Disk diffusion studies showed that oregano was found to be bacteriostatic for Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus, (MRSA) but bacteriocidal for seven other microorganisms. Pseudomonas aeruginosa could not be inhibited by oregano. An ointment consisting of 1-10% oregano could inhibit most organisms except for Proteus mirabilis and Proteus vulgaris, which required 20% and Pseudomonas which could not be inhibited even at the highest concentration of 80%. Oregano extracts can be formulated into an ointment that shows broad antimicrobial activity. Additional testing to assess tissue toxicity and other adverse reactions would be needed prior to human testing.

  6. Sensitive Ground-based Search for Sulfuretted Species on Mars

    NASA Astrophysics Data System (ADS)

    Khayat, Alain; Villanueva, G. L.; Mumma, M. J.; Riesen, T. E.; Tokunaga, A. T.

    2012-10-01

    We searched for active release of gases on Mars during mid Northern Spring and early Northern Summer seasons, between Ls= 34° and Ls= 110°. The targeted volcanic areas, Tharsis and Syrtis Major, were observed during the interval 23 Nov. 2011 to 13 May 2012, using the high resolution infrared spectrometer (CSHELL) on NASA's Infrared Telescope Facility (NASA/IRTF) and the ultra-high resolution heterodyne receiver (Barney) at the Caltech Submillimeter Observatory (CSO). The two main reservoirs of atmospheric sulfur on Mars are expected to be SO2 and H2S. Because these two species have relatively short photochemical lifetimes, 160 and 9 days respectively (Wong et al. 2004), they stand as powerful indicators of recent activity. Carbonyl sulfide (OCS) is the expected end-product of the reactions between sulfuretted species and other molecules in the Martian atmosphere. Our multi-band survey targeted SO2, SO and H2S at their rotational transitions at 346.523 GHz, 304.078 GHz and 300.505 GHz respectively, and OCS in its combination band (ν1+ν3) at 3.42 µm and its fundamental band (ν3) centered at 4.85 µm. The radiative transfer model used to derive abundance ratios for these species was validated by performing line-inversion retrievals on the carbon monoxide (CO) strong rotational (3-2) line at sub-mm wavelengths (rest frequency 345.796 GHz). Preliminary results and abundance ratios for SO2, H2S, SO, OCS and CO will be presented. We gratefully acknowledge support from the NASA Planetary Astronomy Program (AK, ATT, MJM), NASA Astrobiology Institute (MJM), NASA Planetary Atmospheres Program (GLV), and NSF grant number AST-0838261 to support graduate students at the CSO (AK). References: Wong, A.S., Atreya, S. K., Formisano, V., Encrenaz, T., Ignatiev, N.I., "Atmospheric photochemistry above possible martian hot spots", Advances in Space Research, 33 (2004) 2236-2239.

  7. Shape memory alloys for astronomical instrumentation: space and ground-based applications

    NASA Astrophysics Data System (ADS)

    Riva, M.; Rigamonti, D.; Zanetti, F.; Passaretti, F.; Villa, E.; Zerbi, F. M.

    2012-09-01

    This paper wants to illustrate possible applications of Shape Memory Alloy (SMA) as functional devices for space and ground based application in Instrumentations for Astronomy. Thermal activated Shape Memory Alloys are materials able to recover their original shape, after an external deformation, if heated above a characteristic temperature. If the recovery of the shape is completely or partially prevented by the presence of constraints, the material can generate recovery stress. Thanks to this feature, these materials can be positively exploited in Smart Structures if properly embedded into host materials. Some technological processes developed for an ecient use of SMA-based actuators embedded in smart structures tailored to astronomical instrumentation will be presented here. Some possible modeling approaches of the actuators behavior will be addressed taking into account trade- offs between detailed analysis and overall performance prediction as a function of the computational time. The Material characterization procedure adopted for the constitutive laws implementation will be described as well. Deformable composite mirrors,1 opto-mechanical mounting with superelastic kinematic behavior and damping of launch loads onto optical element2 are feasible applications that will be deeply investigated in this paper.

  8. The Palomar kernel-phase experiment: testing kernel phase interferometry for ground-based astronomical observations

    NASA Astrophysics Data System (ADS)

    Pope, Benjamin; Tuthill, Peter; Hinkley, Sasha; Ireland, Michael J.; Greenbaum, Alexandra; Latyshev, Alexey; Monnier, John D.; Martinache, Frantz

    2016-01-01

    At present, the principal limitation on the resolution and contrast of astronomical imaging instruments comes from aberrations in the optical path, which may be imposed by the Earth's turbulent atmosphere or by variations in the alignment and shape of the telescope optics. These errors can be corrected physically, with active and adaptive optics, and in post-processing of the resulting image. A recently developed adaptive optics post-processing technique, called kernel-phase interferometry, uses linear combinations of phases that are self-calibrating with respect to small errors, with the goal of constructing observables that are robust against the residual optical aberrations in otherwise well-corrected imaging systems. Here, we present a direct comparison between kernel phase and the more established competing techniques, aperture masking interferometry, point spread function (PSF) fitting and bispectral analysis. We resolve the α Ophiuchi binary system near periastron, using the Palomar 200-Inch Telescope. This is the first case in which kernel phase has been used with a full aperture to resolve a system close to the diffraction limit with ground-based extreme adaptive optics observations. Excellent agreement in astrometric quantities is found between kernel phase and masking, and kernel phase significantly outperforms PSF fitting and bispectral analysis, demonstrating its viability as an alternative to conventional non-redundant masking under appropriate conditions.

  9. FINDING EXTRATERRESTRIAL LIFE USING GROUND-BASED HIGH-DISPERSION SPECTROSCOPY

    SciTech Connect

    Snellen, I. A. G.; Le Poole, R.; Brogi, M.; Birkby, J.; De Kok, R. J.

    2013-02-20

    Exoplanet observations promise one day to unveil the presence of extraterrestrial life. Atmospheric compounds in strong chemical disequilibrium would point to large-scale biological activity just as oxygen and methane do in the Earth's atmosphere. The cancellation of both the Terrestrial Planet Finder and Darwin missions means that it is unlikely that a dedicated space telescope to search for biomarker gases in exoplanet atmospheres will be launched within the next 25 years. Here we show that ground-based telescopes provide a strong alternative for finding biomarkers in exoplanet atmospheres through transit observations. Recent results on hot Jupiters show the enormous potential of high-dispersion spectroscopy to separate the extraterrestrial and telluric signals, making use of the Doppler shift of the planet. The transmission signal of oxygen from an Earth-twin orbiting a small red dwarf star is only a factor of three smaller than that of carbon monoxide recently detected in the hot Jupiter {tau} Booetis b, albeit such a star will be orders of magnitude fainter. We show that if Earth-like planets are common, the planned extremely large telescopes can detect oxygen within a few dozen transits. Ultimately, large arrays of dedicated flux-collector telescopes equipped with high-dispersion spectrographs can provide the large collecting area needed to perform a statistical study of life-bearing planets in the solar neighborhood.

  10. Ground-based spectroscopic measurements of atmospheric gas composition near Saint Petersburg (Russia)

    NASA Astrophysics Data System (ADS)

    Timofeyev, Yury; Virolainen, Yana; Makarova, Maria; Poberovsky, Anatoly; Polyakov, Alexander; Ionov, Dmitry; Osipov, Sergey; Imhasin, Hamud

    2016-05-01

    Since early 2009, high-resolution solar absorption spectra have been recorded at the Peterhof station (59.88°N, 29.82°E) of Saint Petersburg State University located in the suburbs of St. Petersburg. Measurements are made with the Fourier Transform Infrared (FTIR) system, which consists of Bruker IFS 125HR instrument (with maximum spectral resolution of 0.005 cm-1) and self-designed solar tracker. We derived total column (TC) of a dozen of atmospheric gases from recorded spectra and performed the error analysis of these retrievals. Furthermore, we analysed the temporal variability of the important climatically active gases, such as H2O, CH4, O3, CO, and NO2 near St. Petersburg and compared our retrievals with independent ground-based and satellite data, as well as with the results of EMAC model numerical simulations. Currently, the results of our measurements and the measuring system are under validation for entering the international Network for the Detection of Atmospheric Composition Change (NDACC).

  11. Three dimensional transport speed of wind-drifted ash plumes using ground-based radar

    NASA Astrophysics Data System (ADS)

    Donnadieu, Franck; Valade, Sébastien; Moune, Séverine

    2011-09-01

    The main utilization of mobile ground-based Doppler radars is to quantify the dynamics of eruptive activity by aiming directly at the emission source. We show that they can also provide information on the initial lateral transport speed of weak ash plumes bent over by crosswind. The method is illustrated by measurements made with a transportable volcano Doppler radar (VOLDORAD) at Arenal volcano, Costa Rica. The near-source displacements of the plume are tracked through echo onsets induced by ash entering successive probed volumes in the radar beam. A constant transport velocity is commonly reached within a few seconds of the initial ash emission, as wind advection and buoyancy take over momentum. The plume azimuth and upraise angles are constrained by comparing the amplitude decrease of the radar echoes as a function of distance from the source with results from a simple geometric plume model. The three dimensional vector of the ash cloud transport speed is then reconstructed with an accuracy of a few percent. This method may have applications for volcano monitoring, for determining pyroclast fluxes, for the modeling of tephra dispersal, and for remote measurements of volcanic gas fluxes.

  12. Combination of space- and ground-based astrometric observations to create astrometric catalogs

    NASA Astrophysics Data System (ADS)

    Vondrák, J.; Štefka, V.

    2008-09-01

    Modern space-based astrometric observations made by Hipparcos satellite yielded two principal catalogs in optical wavelength: Hipparcos and Tycho. These catalogs, that recently celebrated ten years of existence, contain star positions with unprecedented accuracy. However, their proper motions are, due to a relatively short interval of Hipparcos mission, quite often not as good as their formal standard errors indicate. This deficiency is especially significant for about twenty per cent of double or multiple stars contained in these catalogs. The combination with ground-based astrometric observations that have much longer history is therefore very important for improving the Hipparcos proper motions. Significant improvement in this respect was achieved during the past years by creating combined catalogs, such as Tycho-2, FK6, GC+HIP, TYC2+HIP, or ARIHIP. Yet a large and important group of astrometric observations of latitude/universal time variations, made in the programs of monitoring Earth orientation, stood apart from these activities. Recently we started to use these observations, covering almost the whole 20th century, to create astrometric catalogs EOC-1, EOC-2, EOC-3 and most recently EOC-4. To construct them, we used the Earth orientation observations in combination with the above mentioned catalogs. The latter two, EOC-3 and EOC-4, contain not only the ``classical'' linear proper motions, but also periodic changes due to orbital motions, for a substantial portion of the observed stars.

  13. Kepler Ground-Based Photometry Proof-of-Concept

    NASA Technical Reports Server (NTRS)

    Brown, Timothy M.; Latham, D.; Howell, S.; Everett, M.

    2004-01-01

    We report on our efforts to evaluate the feasibility of using the 4-Shooter CCD camera on the 48-inch reflector at the Whipple Observatory to carry out a multi-band photometric survey of the Kepler target region. We also include recommendations for future work. We were assigned 36 nights with the &hooter during 2003 for this feasibility study. Most of the time during the first two dozen nights was dedicated to the development of procedures, test exposures, and a reconnaissance across the Kepler field. The final 12 nights in September and October 2003 were used for "production" observing in the middle of the Kepler field using the full complement of seven filters (SDSS u, g, r, i, z, plus our special Gred and D51 intermediate-band filters). Nine of these 12 nights were clear and photometric, and production observations were obtained at 109 pointings, corresponding to 14.6 square degrees.

  14. Space power by ground-based laser transmission

    SciTech Connect

    Landis, G.A. NASA, Lewis Research Center, Cleveland, OH )

    1992-07-01

    A new method for providing power to space vehicles consists of using high-power CW lasers on the ground to beam power to photovoltaic receivers in space. Such large lasers could be located at cloud-free sites at one or more ground locations, and use large mirrors with adaptive optical correction to reduce the beam spread due to diffraction or atmospheric turbulence. This can result in lower requirements for battery storage, due to continuous illumination of arrays even during periods of shadow by the earth, and higher power output, due to the higher efficiency of photovoltaic arrays under laser illumination compared to solar and the ability to achieve higher intensities of illumination. Applications include providing power for satellites during eclipse, providing power to resurrect satellites which are failing due to solar array degradation, powering orbital transfer vehicles or lunar transfer shuttles, and providing night power to a solar array on the moon. 22 refs.

  15. Identification of Thermally Driven Valley Wind From Ground Based and Airborne Measurements

    NASA Astrophysics Data System (ADS)

    Rampanelli, G.; de Franceschi, M.; Zardi, D.

    A peculiar valley wind, the so called Ora del Garda, has been adopted as a test case of thermally driven wind. The latter occurs on fair weather days, when it starts blowing during the late morning along the northern shore of Garda Lake as a typical lake breeze and thence channels in the Sarca Valley and Lakes Valley nearby, until it finally reaches, through an elevated saddle, the River Adige Valley, where it appears as a strong gusty wind. A statistical analysis of time series recorded by a network of meteorological ground station located in the above valleys allowed detailed identifi- cation of peculiar features. Further understanding has been gained from specific field observations including both ground based and airborne measurements performed with a light airplane within and above the valley boundary layer. A geostatistical analy- sis (kriging) of data allowed evaluation of vertical profiles at various locations. Deviations from the averaged vertical profile due to horizontal temperature gradients within the valley atmosphere were also evaluated and the underlying statistical struc- ture estimated in terms of suitable variogram function of the monitored variables. Fi- nally the procedure allowed an estimate potential temperature anomalies throughout the valley volume and the identification of basic thermal structures within the convec- tive boundary layer.

  16. Perspective ground-based method for diagnostics of the lower ionosphere and the neutral atmosphere

    NASA Astrophysics Data System (ADS)

    Bakhmetieva, N. V.; Grigoriev, G. I.; Tolmacheva, A. V.

    We present a new perspective ground-based method for diagnostics of the ionosphere and atmosphere parameters. The method uses one of the numerous physical phenomena observed in the ionosphere illuminated by high-power radio waves. It is a generation of the artificial periodic irregularities (APIs) in the ionospheric plasma. The APIs were found while studying the effects of ionospheric high-power HF modification. It was established that the APIs are formed by a standing wave that occurs due to interference between the upwardly radiated radio wave and its reflection off the ionosphere. The API studies are based upon observation of the Bragg backscatter of the pulsed probe radio wave from the artificial periodic structure. Bragg backscatter occurs if the spatial period of the irregularities is equal to half a wavelength of the probe signal. The API techniques makes it possible to obtain the following information: the profiles of electron density from the lower D-region up to the maximum of the F-layer; the irregular structure of the ionosphere including split of the regular E-layer, the sporadic layers; the vertical velocities in the D- and E-regions of the ionosphere; the turbulent velocities, turbulent diffusion coefficients and the turbopause altitude; the neutral temperatures and densities at the E-region altitudes; the parameters of the internal gravity waves and their spectral characteristics; the relative concentration of negative oxygen ions in the D-region. Some new results obtained by the API technique are discussed .

  17. Piloted simulation of a ground-based time-control concept for air traffic control

    NASA Technical Reports Server (NTRS)

    Davis, Thomas J.; Green, Steven M.

    1989-01-01

    A concept for aiding air traffic controllers in efficiently spacing traffic and meeting scheduled arrival times at a metering fix was developed and tested in a real time simulation. The automation aid, referred to as the ground based 4-D descent advisor (DA), is based on accurate models of aircraft performance and weather conditions. The DA generates suggested clearances, including both top-of-descent-point and speed-profile data, for one or more aircraft in order to achieve specific time or distance separation objectives. The DA algorithm is used by the air traffic controller to resolve conflicts and issue advisories to arrival aircraft. A joint simulation was conducted using a piloted simulator and an advanced concept air traffic control simulation to study the acceptability and accuracy of the DA automation aid from both the pilot's and the air traffic controller's perspectives. The results of the piloted simulation are examined. In the piloted simulation, airline crews executed controller issued descent advisories along standard curved path arrival routes, and were able to achieve an arrival time precision of + or - 20 sec at the metering fix. An analysis of errors generated in turns resulted in further enhancements of the algorithm to improve the predictive accuracy. Evaluations by pilots indicate general support for the concept and provide specific recommendations for improvement.

  18. Ground-based remote sensing of thin clouds in the Arctic

    NASA Astrophysics Data System (ADS)

    Garrett, T. J.; Zhao, C.

    2012-11-01

    This paper describes a method for using interferometer measurements of downwelling thermal radiation to retrieve the properties of single-layer clouds. Cloud phase is determined from ratios of thermal emission in three "micro-windows" where absorption by water vapor is particularly small. Cloud microphysical and optical properties are retrieved from thermal emission in two micro-windows, constrained by the transmission through clouds of stratospheric ozone emission. Assuming a cloud does not approximate a blackbody, the estimated 95% confidence retrieval errors in effective radius, visible optical depth, number concentration, and water path are, respectively, 10%, 20%, 38% (55% for ice crystals), and 16%. Applied to data from the Atmospheric Radiation Measurement program (ARM) North Slope of Alaska - Adjacent Arctic Ocean (NSA-AAO) site near Barrow, Alaska, retrievals show general agreement with ground-based microwave radiometer measurements of liquid water path. Compared to other retrieval methods, advantages of this technique include its ability to characterize thin clouds year round, that water vapor is not a primary source of retrieval error, and that the retrievals of microphysical properties are only weakly sensitive to retrieved cloud phase. The primary limitation is the inapplicability to thicker clouds that radiate as blackbodies.

  19. Determining F-factor using ground-based Doppler radar: Validation and results

    NASA Technical Reports Server (NTRS)

    Elmore, K. L.; Albo, E. D.; Goodrich, R. K.

    1994-01-01

    Using a two-dimensional linear least-squares method applied to Doppler radar data, we test the viability of determining F-factor remotely. The ultimate application of such an algorithm will be supplying real-time F-factor maps, derived from ground-based Doppler radars to air traffic control personnel and pilots. Data from NASA deployments to the MIT/Lincoln Lab TDWR testbed radar in Orlando in 1991 and 1992 along with NASA deployments to the NCAR TDWR testbed radar in Denver are examined. Preliminary analyses show that the two-dimensional method correlates reasonably well with in situ measurements. Several effects, independent of the method used, act to reduce the correlation to less than one. These include time differences between radar and aircraft data, vertical misalignment between the aircraft and the radar beam, different spatial resolution scales between aircraft and radar data, inhomogeneous radar beam filling, noise in radar data that eludes filtering, and phase lag between time and space due to low pass filtering of the aircraft data. In the final assessment, it appears that a shear-based F-factor algorithm is preferable to the currently implemented TDWR algorithms which lack any local shear estimates.

  20. A case for using ground-based thermal inertia measurements to detect Martian caves.

    PubMed

    Groemer, Gernot; Foresta, Luca; Turetschek, Thomas; Bothe, Claudia; Boyd, Andrea; Dinkelaker, Aline; Dissertori, Markus; Fasching, David; Fischer, Monika; Föger, Daniel; Frischauf, Norbert; Fritsch, Lukas; Fuchs, Harald; Gautsch, Christoph; Gerard, Stephan; Goetzloff, Linda; Gołebiowska, Izabella; Gorur, Paavan; Groemer, Gerhard; Groll, Petra; Haider, Christian; Haider, Olivia; Hauth, Eva; Hauth, Stefan; Hettrich, Sebastian; Jais, Wolfgang; Jones, Natalie; Taj-Eddine, Kamal; Karl, Alexander; Kauerhoff, Tilo; Khan, Muhammad Shadab; Kjeldsen, Andreas; Klauck, Jan; Losiak, Anna; Luger, Markus; Luger, Thomas; Luger, Ulrich; McArthur, Jane; Moser, Linda; Neuner, Julia; Orgel, Csilla; Ori, Gian Gabriele; Paternesi, Roberta; Peschier, Jarno; Pfeil, Isabella; Prock, Silvia; Radinger, Josef; Ragonig, Christoph; Ramirez, Barbara; Ramo, Wissam; Rampey, Mike; Sams, Arnold; Sams, Elisabeth; Sams, Sebastian; Sandu, Oana; Sans, Alejandra; Sansone, Petra; Scheer, Daniela; Schildhammer, Daniel; Scornet, Quentin; Sejkora, Nina; Soucek, Alexander; Stadler, Andrea; Stummer, Florian; Stumptner, Willibald; Taraba, Michael; Tlustos, Reinhard; Toferer, Ernst; Winter, Egon; Zanella-Kux, Katja

    2014-05-01

    Martian caves are regarded as one of the most interesting locations in which to search for life on the planet. Data obtained during the MARS2013 expedition at Hamar Laghdad Ridge in the Tafilalt region of Morocco indicate that even small cavities can display thermal behavior that is characteristic for caves. For example, temperature in a cavity equaled 14°C±0.1°C before sunrise, which was higher than the temperature of the ambient air (10°C±0.1°C) and proximate rocks (9°C±0.1°C) at the same time. Within 30 min after sunrise, when the temperature of surrounding rocks corresponded to 15°C, this thermal relationship reversed. Measurements were conducted under simulated spaceflight conditions, including near-real-time interpretation of data that were acquired in a complex flight planning environment. We conclude that using ground-based thermal contrast measurements, in 7-14 μm band before and after sunset, is an effective method for Mars astronauts to identify caves, possibly superior to usage of space-based or ground-penetrating data.

  1. On Advanced Estimation Techniques for Exoplanet Detection and Characterization using Ground-Based Coronagraphs

    NASA Technical Reports Server (NTRS)

    Lawson, Peter R.; Frazin, Richard; Barrett, Harrison; Caucci, Luca; Devaney, Nicholas; Furenlid, Lars; Gladysz, Szymon; Guyon, Olivier; Krist, John; Maire, Jerome; Marois, Christian; Mawet, Dimitri; Mouillet, David; Mugnier, Laurent; Perrin, Marshall; Poyneer, Lisa; Pueyo, Laurent; Savransky, Dmitry; Soummer, Remi

    2012-01-01

    The direct imaging of planets around nearby stars is exceedingly difficult. Only about 14 exoplanets have been imaged to date that have masses less than 13 times that of Jupiter. The next generation of planet-finding coronagraphs, including VLT-SPHERE, the Gemini Planet Imager, Palomar P1640, and Subaru HiCIAO have predicted contrast performance of roughly a thousand times less than would be needed to detect Earth-like planets. In this paper we review the state of the art in exoplanet imaging, most notably the method of Locally Optimized Combination of Images (LOCI), and we investigate the potential of improving the detectability of faint exoplanets through the use of advanced statistical methods based on the concepts of the ideal observer and the Hotelling observer. We provide a formal comparison of techniques through a blind data challenge and evaluate performance using the Receiver Operating Characteristic (ROC) and Localization ROC (LROC) curves. We place particular emphasis on the understanding and modeling of realistic sources of measurement noise in ground-based AO-corrected coronagraphs. The work reported in this paper is the result of interactions between the co-authors during a week-long workshop on exoplanet imaging that was held in Squaw Valley, California, in March of 2012.

  2. On Advanced Estimation Techniques for Exoplanet Detection and Characterization using Ground-based Coronagraphs

    NASA Technical Reports Server (NTRS)

    Lawson, Peter; Frazin, Richard

    2012-01-01

    The direct imaging of planets around nearby stars is exceedingly difficult. Only about 14 exoplanets have been imaged to date that have masses less than 13 times that of Jupiter. The next generation of planet-finding coronagraphs, including VLT-SPHERE, the Gemini Planet Imager, Palomar P1640, and Subaru HiCIAO have predicted contrast performance of roughly a thousand times less than would be needed to detect Earth-like planets. In this paper we review the state of the art in exoplanet imaging, most notably the method of Locally Optimized Combination of Images (LOCI), and we investigate the potential of improving the detectability of faint exoplanets through the use of advanced statistical methods based on the concepts of the ideal observer and the Hotelling observer. We propose a formal comparison of techniques using a blind data challenge with an evaluation of performance using the Receiver Operating Characteristic (ROC) and Localization ROC (LROC) curves. We place particular emphasis on the understanding and modeling of realistic sources of measurement noise in ground-based AO-corrected coronagraphs. The work reported in this paper is the result of interactions between the co-authors during a week-long workshop on exoplanet imaging that was held in Squaw Valley, California, in March of 2012

  3. TeV γ-ray astronomy with ground-based air-shower arrays

    NASA Astrophysics Data System (ADS)

    Mostafá, Miguel A.

    2016-07-01

    The TeV energy band is a very exciting window into the origin of high energy cosmic radiation, particle acceleration, and the annihilation of dark matter particles. Above a few hundred GeV, ground-based experiments of very large effective areas open a new domain to study extragalactic sources at intermediate redshifts, galaxy clusters, gamma ray bursts, AGN and their flaring states, extended sources and galactic diffuse emission, and to indirect searches for dark matter. In particular, ground arrays of particle detectors -that operate with high duty cycles and large fields of view- can extend to multi-TeV energies the measurements made with experiments on satellites, and complement the observations done with air Cherenkov telescopes on the ground. Key science goals of ground arrays include performing unbiased all-sky surveys, monitoring of transient events from known (and unknown) sources, and detecting extended regions of diffuse emission. In this paper, the status and most recent results from ARGO-YBJ, Tibet AS, HAWC, and LHAASO are presented.

  4. Development of ground-based ELF/VLF receiver system in Wuhan and its first results

    NASA Astrophysics Data System (ADS)

    Chen, Yanping; Yang, Guobin; Ni, Binbin; Zhao, Zhengyu; Gu, Xudong; Zhou, Chen; Wang, Feng

    2016-05-01

    A new digital low-frequency receiver system has been developed at Wuhan University for sensitive reception of low-latitude broadband Extremely Low Frequency (ELF) and Very Low Frequency (VLF) radio waves originating from either natural or artificial sources. These low-frequency radio waves are useful for ionospheric remote sensing, geospace environment monitoring, and submarine communications. This paper presents the principle and architecture of the system framework, including magnetic loop antenna design, low-noise analog front-end and digital receiver with data sampling and transmission. A new structure is adopted in the analog front end to provide high common-mode rejection and to reduce interference. On basis of field programmable gate array (FPGA) device and Universal Serial Bus (USB) architecture, the digital receiver is developed along with time keeping and synchronization module. The validity and feasibility of the self-developed ground-based ELF/VLF receiver system is evaluated by first results of experimental data that show the temporal variation of broadband ELF/VLF wave spectral intensity in Wuhan (30.54 °N, 114.37 °E). In addition to the acquisition of VLF transmitter signals at various frequencies, tweek atmospherics are also clearly captured to occur at multiple modes up to n = 6.

  5. On Advanced Estimation Techniques for Exoplanet Detection and Characterization Using Ground-based Coronagraphs

    PubMed Central

    Lawson, Peter R.; Poyneer, Lisa; Barrett, Harrison; Frazin, Richard; Caucci, Luca; Devaney, Nicholas; Furenlid, Lars; Gładysz, Szymon; Guyon, Olivier; Krist, John; Maire, Jérôme; Marois, Christian; Mawet, Dimitri; Mouillet, David; Mugnier, Laurent; Pearson, Iain; Perrin, Marshall; Pueyo, Laurent; Savransky, Dmitry

    2015-01-01

    The direct imaging of planets around nearby stars is exceedingly difficult. Only about 14 exoplanets have been imaged to date that have masses less than 13 times that of Jupiter. The next generation of planet-finding coronagraphs, including VLT-SPHERE, the Gemini Planet Imager, Palomar P1640, and Subaru HiCIAO have predicted contrast performance of roughly a thousand times less than would be needed to detect Earth-like planets. In this paper we review the state of the art in exoplanet imaging, most notably the method of Locally Optimized Combination of Images (LOCI), and we investigate the potential of improving the detectability of faint exoplanets through the use of advanced statistical methods based on the concepts of the ideal observer and the Hotelling observer. We propose a formal comparison of techniques using a blind data challenge with an evaluation of performance using the Receiver Operating Characteristic (ROC) and Localization ROC (LROC) curves. We place particular emphasis on the understanding and modeling of realistic sources of measurement noise in ground-based AO-corrected coronagraphs. The work reported in this paper is the result of interactions between the co-authors during a week-long workshop on exoplanet imaging that was held in Squaw Valley, California, in March of 2012. PMID:26347393

  6. Complex System for Ground-Based and Accelerated Simulation of Six Extremal Space Factors (KIFK)

    NASA Astrophysics Data System (ADS)

    Abraimov, V. V.; Kolybaev, L. K.; Verkhovtseva, E. T.; Nekludov, I. M.; Rybalko, V. F.; Borts, B. V.

    This work was aimed at 1. Development and construction of a complex SF simulator for simultaneous and accelerated simulation of six SF (unparalleled in the GUS and ESA countries): artificial Sun radiation (200..2500 nm) + VUV radiation (5..200 nm) + proton (p+) and electron (e-) radiation (50..200 keV) + vacuum (10-6 Torr) + thermocycling (4.2..400 K). 2.Development of new physical techniques of accelerated laboratory simulation of the basic space factors adequate to natural factors influencing materials, components, units and scale models of spacecraft. In our opinion, this work solves a number of topical problems of ground-based simulation of space factors. 1.Simultaneous impact of six SF on spacecraft materials and models. 2.Simulation of the complete electromagnetic solar radiation (including VUV) spectrum in the wavelength range 5..2500 nm. 3.Accelerated simulation of the electron and proton flows of the Earth's radiation belts (the energy 50..200 keV, intensity 1012 particle/cm2s), i.e. with the acceleration coefficient 500..1000. 4.Accelerated simulation of the VUV component of the Sun's spectrum with the maximum intensity 3000 erg/cm2s) (i.e., the acceleration coefficient 300) 5.Simultaneous thermocycling of test objects in a wide range of temperatures 4.2..400 K in the vacuum of 10-6 Torr.

  7. Ground-based observations of uranus and neptune using CCD instruments

    SciTech Connect

    Smith, B.A.

    1985-07-01

    The author verifies that with the help of charge-coupled devices (CCD) great progress is being made in ground-based astronomical observations, including the study of the remote giant planets Uranus and Neptune. In reading the CCD the top row of pixels (potential wells) is moved into the sequential (shift) reading register; after this each row (line) of pixels moves its electrons upward (in each column) until the bottom row is cleared. This process is repeated for each row until the device is interrogated sequentially. The use of CCD detectors for purposes of image acquisition and spectroscopy has already found wide popularity at astronomical observatories, and soon it will spread to space research. The first known attempts to use CCD to obtain astronomical images was made by the author and his colleagues in April 1976. The result was the first observations of structure on the dark disk of Uranus. In general, the more refined the mathematical provision, the more information can be extracted from the images or spectra.

  8. Estimating regional auroral electron energy deposition using ground-based optical measurements

    NASA Astrophysics Data System (ADS)

    Hampton, D. L.; Conde, M.; Ahrns, M. J.; Bristow, W.; Lynch, K. A.; Zettergren, M. D.

    2014-12-01

    Two key parameters for understanding the coupling between the magnetosphere and the thermosphere/ionosphere in polar regions are the characteristic energy and the total energy flux of precipitating auroral electrons. Ionization due to precipitating electrons modifies the ionospheric electron density profile and thereby the height-dependent conductivity in a complex manner in both time and space. Global or regional thermospheric dynamics models typically rely on empirical models (Ovation) or low-resolution global EUV imagery (POLAR) for electron precipitation input which smear out the mesoscale detail of the location and timing of auroral arcs. We have developed a method for measuring the time-dependent auroral electron energy deposition over a several-hundred km range with 25 km resolution using a combination of two ground-based optical instruments - a scanning-doppler imager observing green-line temperatures and a filtered all-sky imager measuring the N2+ first negative emission at 427.8 nm. We will discuss the details of the method, and show several examples including those from the MICA sounding rocket experiment as well as several events from the AMISR PINOT campaign. We will also show comparisons with alternate optical and radar techniques, compare our estimated energy flux to those from Ovation, and discuss limitations and advantages of the technique when examining mesoscale dynamics in the auroral zone.

  9. Ground-based analysis of volcanic ash plumes using a new multispectral thermal infrared camera approach

    NASA Astrophysics Data System (ADS)

    Williams, D.; Ramsey, M. S.

    2015-12-01

    Volcanic plumes are complex mixtures of mineral, lithic and glass fragments of varying size, together with multiple gas species. These plumes vary in size dependent on a number of factors, including vent diameter, magma composition and the quantity of volatiles within a melt. However, determining the chemical and mineralogical properties of a volcanic plume immediately after an eruption is a great challenge. Thermal infrared (TIR) satellite remote sensing of these plumes is routinely used to calculate the volcanic ash particle size variations and sulfur dioxide concentration. These analyses are commonly performed using high temporal, low spatial resolution satellites, which can only reveal large scale trends. What is lacking is a high spatial resolution study specifically of the properties of the proximal plumes. Using the emissive properties of volcanic ash, a new method has been developed to determine the plume's particle size and petrology in spaceborne and ground-based TIR data. A multispectral adaptation of a FLIR TIR camera has been developed that simulates the TIR channels found on several current orbital instruments. Using this instrument, data of volcanic plumes from Fuego and Santiaguito volcanoes in Guatemala were recently obtained Preliminary results indicate that the camera is capable of detecting silicate absorption features in the emissivity spectra over the TIR wavelength range, which can be linked to both mineral chemistry and particle size. It is hoped that this technique can be expanded to isolate different volcanic species within a plume, validate the orbital data, and ultimately to use the results to better inform eruption dynamics modelling.

  10. Ground-Based IR Spectroscopy of Mercury for Composition

    NASA Technical Reports Server (NTRS)

    Killen, Rosemary M.

    2001-01-01

    Remote sensing measurements of the Moon and Mercury in the thermal infrared have been plagued with problems due to atmospheric absorption and other effects. Controversial results have been discussed by Nash et al. and by Salisbury et al.. We have developed a technique to obtain thermal infrared spectra of Mercury together with solar and sky spectra in the 8-13 micrometer region suitable for determining the presence or absence of mineralogical features. High-resolution (0.05 cm(exp -1) between data points) spectra were obtained during daylight using the Fourier Transform Spectrograph (FTS) at the McMath-Pierce Solar Telescope Facility at Kitt Peak National Observatory, Arizona. The reduced data were independent of any model of the transmission of the Earth's atmosphere and rest on a calibration using sky spectra along the same line-of-sight through the atmosphere as the actual Mercury raw spectrum. This method can be applied at all solar elongation angles including small elongation angles (5 deg or less). The basic sequence and the technique are robust.

  11. The diverse utility of ground-based magnetometer data

    NASA Astrophysics Data System (ADS)

    Love, J. J.

    2012-12-01

    The global network of magnetic observatories represents a unique collective asset for the scientific community. Since observatory data record a wide range of physical phenomena, they are also used for a wide range of applications. Historically, magnetic observatories were first established in the 19th century to support global magnetic-field mapping projects, and this application continues to be important today. But since the dawn of the space age and the International Geophysical Year, observatory data have become important for research analysis of the ionosphere, the magnetosphere, and, indirectly, the heliosphere. Over the past couple of solar cycles, magnetic observatories have also played an important role in real-time operational monitoring of the changing conditions of space weather and assessment of ground-level geomagnetic hazards. This diversification and expansion of the observatory-data user community has brought demands for data that meet new and more stringent standards. In cooperation with the many institutes that support magnetic observatories, INTERMAGNET has been helping to coordinate and facilitate observatory modernization and improved operation. In this presentation, we give an overview of the diversity of signals recorded in observatory data, including secular, quiet, storm-time, and solar-cycle variations. We discuss future opportunities, especially for global integration and data sharing.

  12. Ground-based measurements of Joule heating rates

    SciTech Connect

    De La Beaujardiere, O.; Johnson, R.; Wickwar, V.B.

    1989-04-03

    Joule heating in the upper atmosphere is the most-important energy-dissipation process between the magnetosphere and the ionosphere. This paper examines the various terms in the equation that governs Joule heating. (1) The ionospheric electric-field seasonal dependence is examined. It is found that the shape of the ionospheric plasma convection cells, and the latitude of the reversal from sunward to antisunward convection, are seasonally dependent. Statistical averages of the square of the ion velocity show a maximum in fall, and a minimum in summer. (2) Pedersen conductivities at F-region altitudes are examined using Chatanika and Sondrestrom radar data. It is shown that during solar minimum conditions, the F-region contributes less than 20% to the total height integrated Pedersen conductivity sigma p. In contrast, during solar maximum conditions the contribution to sigma from solar produced F-region ionization can be 60%. (3) The importance of the neutral wind term in Joule heating calculations is illustrated using a specific example. The Joule heating calculated by including the neutral wind term is 2 to 4 times smaller than that calculated without the neutral wind. But the reverse can also be true, as shown during a period when the neutral wind played the role of a dynamo in the ionosphere/magnetosphere current.

  13. Ground-based Remote Sensing of Cloud Liquid Water Path

    NASA Astrophysics Data System (ADS)

    Crewell, S.; Loehnert, U.

    Within the BALTEX Cloud LIquid WAter NETwork (CLIWA-NET) measurements of cloud parameters were performed to improve/evaluate cloud parameterizations in numerical weather prediction and climate models. The key variable is the cloud liq- uid water path (LWP) which is measured by passive microwave radiometry from the ground during three two-month CLIWA-NET observational periods. Additionally to the high temporal resolution time series from the ground, LWP fields are derived from satellite measurements. During the first two campaigns a continental scale network consisting of 12 stations was established. Most stations included further cloud sen- sitive instruments like infrared radiometer and lidar ceilometer. The third campaign started with a two-week long microwave intercomparison campaign (MICAM) in Cabauw, The Netherlands, and proceeded with a regional network within a 100 by 100 km area. The presentation will focus on the accuracy of LWP derived from the ground by in- vestigating the accuracy of the microwave brightness temperature measurement and examining the LWP retrieval uncertainty. Up to now microwave radiometer are no standard instruments and the seven radiometer involved in MICAM differ in frequen- cies, bandwidths, angular resolution, integration time etc. The influence of this instru- ment specifications on the LWP retrieval will be discussed.

  14. Calibrating ground-based microwave radiometers: Uncertainty and drifts

    NASA Astrophysics Data System (ADS)

    Küchler, N.; Turner, D. D.; Löhnert, U.; Crewell, S.

    2016-04-01

    The quality of microwave radiometer (MWR) calibrations, including both the absolute radiometric accuracy and the spectral consistency, determines the accuracy of geophysical retrievals. The Microwave Radiometer Calibration Experiment (MiRaCalE) was conducted to evaluate the performance of MWR calibration techniques, especially of the so-called Tipping Curve Calibrations (TCC) and Liquid Nitrogen Calibrations (LN2cal), by repeatedly calibrating a fourth-generation Humidity and Temperature Profiler (HATPRO-G4) that measures downwelling radiance between 20 GHz and 60 GHz. MiRaCalE revealed two major points to improve MWR calibrations: (i) the necessary repetition frequency for MWR calibration techniques to correct drifts, which ensures stable long-term measurements; and (ii) the spectral consistency of control measurements of a well known reference is useful to estimate calibration accuracy. Besides, we determined the accuracy of the HATPRO's liquid nitrogen-cooled blackbody's temperature. TCCs and LN2cals were found to agree within 0.5 K when observing the liquid nitrogen-cooled blackbody with a physical temperature of 77 K. This agreement of two different calibration techniques suggests that the brightness temperature of the LN2 cooled blackbody is accurate within at least 0.5 K, which is a significant reduction of the uncertainties that have been assumed to vary between 0.6 K and 1.5 K when calibrating the HATPRO-G4. The error propagation of both techniques was found to behave almost linearly, leading to maximum uncertainties of 0.7 K when observing a scene that is associated with a brightness temperature of 15 K.

  15. Retrieval of aerosol composition using ground-based remote sensing measurements

    NASA Astrophysics Data System (ADS)

    Xie, Yisong; Li, Zhengqiang; Zhang, Ying; Li, Donghui; Li, Kaitao

    2016-04-01

    The chemical composition and mixing states of ambient aerosol are the main factors deciding aerosol microphysical and optical properties, and thus have significant impacts on regional or global climate change and air quality. Traditional approaches to detect atmospheric aerosol composition include sampling with laboratory analysis and in-situ measurements. They can accurately acquire aerosol components, however, the sampling or air exhausting could change the status of ambient aerosol or lead to some mass loss. Additionally, aerosol is usually sampled at the surface level so that it is difficult to detect the columnar aerosol properties. Remote sensing technology, however, can overcome these problems because it is able to detect aerosol information of entire atmosphere by optical and microphysical properties without destructing the natural status of ambient aerosol. This paper introduces a method to acquire aerosol composition by the remote sensing measurements of CIMEL CE318 ground-based sun-sky radiometer. A six component aerosol model is used in this study, including one strong absorbing component Black Carbon (BC), two partly absorbing components Brown Carbon (BrC) and Mineral Dust (MD), two scattering components Ammonia Sulfate-like (AS) and Sea Salt (SS), and Aerosol Water uptake (AW). Sensitivity analysis are performed to find the most sensitive parameters to each component and retrieval method for each component is accordingly developed. Different mixing models such as Maxwell-Garnett (MG), Bruggeman (BR) and Volume Average (VA) are also studied. The residual minimization method is used by comparing remote sensing measurements and simulation outputs to find the optimization of aerosol composition (including volume fraction and mass concentration of each component). This method is applied to measurements obtained from Beijing site under different weather conditions, including polluted haze, dust storm and clean days, to investigate the impacts of mixing

  16. Retrieval of aerosol composition using ground-based remote sensing measurements

    NASA Astrophysics Data System (ADS)

    Xie, Y.; Li, Z.; Xu, H.; Chen, X.; Li, K.; Lv, Y.; Li, D.; Zhang, Y.

    2015-12-01

    The chemical composition and mixing status of ambient aerosol are the main factors deciding aerosol microphysical and optical properties, and thus have significant impacts on regional or global climate change and air quality. Traditional approaches to detect atmospheric aerosol composition include sampling with laboratory analysis and in-situ measurement. They can accurately acquire aerosol components, however, the sampling or air exhausting could change the status of aerosol or have some mass loss. Additionally, aerosol is usually sampled at the surface level so that it is difficult to detect the columnar aerosol properties. Remote sensing technology, however, can overcome these problems because it investigate aerosol information by optical and microphysical properties without destructing the natural status of ambient aerosol. This paper introduce a method to acquire aerosol composition by the remote sensing measurements of CIMEL CE318 ground-based sun-sky radiometer. A six component aerosol model is used in this study, including one strong absorbing component Black Carbon (BC), two partly absorbing components Brown Carbon (BrC) and Mineral Dust (MD), two scattering components Ammonia Sulfate-like (AS) and Sea Salt (SS), and Aerosol Water uptake (AW). Sensitivity analysis are performed to find the most sensitive parameters to each component and retrieval method for each component is accordingly developed. The residual minimization method is used by comparing remote sensing measurements and simulation outputs to find the optimization of aerosol composition (including volume fraction and mass concentration of each component). This method is applied to real measurements obtained from Beijing site under different weather conditions, including polluted haze, dust storm and clean days, to investigate the impacts of mixing states of aerosol particles on aerosol composition retrieval.

  17. "Sniffing" Jupiter's moon Europa through ground-based IR observations

    NASA Astrophysics Data System (ADS)

    Paganini, Lucas; Mumma, Michael J.; Hurford, Terry; Roth, Lorenz; Villanueva, Geronimo Luis

    2016-10-01

    The ability to sample possible plumes from the subsurface ocean in Europa represents a major step in our search for extraterrestrial life. If plumes exist, sampling the effluent material would provide insights into their chemistry and relevant information about the prospect that life could exist, or now exists, within the ocean. Most of the difficulties in detecting plumes come from the less frequent observational coverage of Europa, which contrasts strongly with the frequent Cassini flybys of Enceladus (Spencer & Nimmo 2013). Recent observations have been taken with HST/STIS in 2014/2015, but results have shown no evident confirmation of the 2012 plume detection (Roth et al. 2014, 2015). Future in situ observations (Europa Mission) will provide definitive insights, but not before the spacecraft's arrival in ~2025, thus an interim approach is needed to inform such space mission planning and to complement existing observations at other wavelengths.In 2015, we initiated a strong campaign to build a comprehensive survey of possible plumes on Europa through high-resolution IR spectroscopy with Keck/NIRSPEC. We were awarded 10 nights out of 15 total nights available for Key Strategic Mission Support projects for the 2016A, 2016B, 2017A, and 2017B semesters under NASA time with the Keck Observatory. In 2016A, we observed Europa during 10 half-nights and will continue to do so for another 10 half-nights in 2017A. We target a serendipitous search of gaseous activity from Europa to confirm and constrain the chemical composition of possible Europan plumes that can aid the investigation of physical processes underlying (or on) its surface. Ultimately, we seek to: (1) provide information that can inform planning for NASA's Europa mission, (2) further our current understanding of Europa's gas environment, and (3) complement studies that are currently underway with other facilities (like the Hubble Space Telescope). In this presentation, we will discuss preliminary results

  18. Volcano geodesy at Santiaguito using ground-based cameras and particle image velocimetry

    NASA Astrophysics Data System (ADS)

    Johnson, J.; Andrews, B. J.; Anderson, J.; Lyons, J. J.; Lees, J. M.

    2012-12-01

    The active Santiaguito dome in Guatemala is an exceptional field site for ground-based optical observations owing to the bird's-eye viewing perspective from neighboring Santa Maria Volcano. From the summit of Santa Maria the frequent (1 per hour) explosions and continuous lava flow effusion may be observed from a vantage point, which is at a ~30 degree elevation angle, 1200 m above and 2700 m distant from the active vent. At these distances both video cameras and SLR cameras fitted with high-power lenses can effectively track blocky features translating and uplifting on the surface of Santiaguito's dome. We employ particle image velocimetry in the spatial frequency domain to map movements of ~10x10 m^2 surface patches with better than 10 cm displacement resolution. During three field campaigns to Santiaguito in 2007, 2009, and 2012 we have used cameras to measure dome surface movements for a range of time scales. In 2007 and 2009 we used video cameras recording at 30 fps to track repeated rapid dome uplift (more than 1 m within 2 s) of the 30,000 m^2 dome associated with the onset of eruptive activity. We inferred that the these uplift events were responsible for both a seismic long period response and an infrasound bimodal pulse. In 2012 we returned to Santiaguito to quantify dome surface movements over hour-to-day-long time scales by recording time lapse imagery at one minute intervals. These longer time scales reveal dynamic structure to the uplift and subsidence trends, effusion rate, and surface flow patterns that are related to internal conduit pressurization. In 2012 we performed particle image velocimetry with multiple cameras spatially separated in order to reconstruct 3-dimensional surface movements.

  19. Comparison of ground-based and space flight energy expenditure and water turnover in middle-aged healthy male US astronauts.

    PubMed

    Lane, H W; Gretebeck, R J; Schoeller, D A; Davis-Street, J; Socki, R A; Gibson, E K

    1997-01-01

    Energy requirements during space flight are poorly defined because they depend on metabolic-balance studies, food disappearance, and dietary records. Water turnover has been estimated by balance methods only. The purpose of this study was to determine energy requirements and water turnover for short-term space flights (8-14 d). Subjects were 13 male astronauts aged 36-51 y with normal body mass indexes (BMIs). Total energy expenditure (TEE) was determined during both a ground-based period and space flight and compared with the World Health Organization (WHO) calculations of energy requirements and dietary intake. TEE was not different for the ground-based and the space-flight periods (12.40 +/- 2.83 and 11.70 +/- 1.89 MJ/d, respectively), and the WHO calculation using the moderate activity correction was a good predictor of TEE during space flight. During the ground-based period, energy intake and TEE did not differ, but during space flight energy intake was significantly lower than TEE; body weight was also less at landing than before flight. Water turnover was lower during space flight than during the ground-based period (2.7 +/- 0.6 compared with 3.8 +/- 0.5 L/d), probably because of lower fluid intakes and perspiration loss during flight. This study confirmed that the WHO calculation can be used for male crew members' energy requirements during short space flights.

  20. Comparison of ground-based and space flight energy expenditure and water turnover in middle-aged healthy male US astronauts

    NASA Technical Reports Server (NTRS)

    Lane, H. W.; Gretebeck, R. J.; Schoeller, D. A.; Davis-Street, J.; Socki, R. A.; Gibson, E. K.

    1997-01-01

    Energy requirements during space flight are poorly defined because they depend on metabolic-balance studies, food disappearance, and dietary records. Water turnover has been estimated by balance methods only. The purpose of this study was to determine energy requirements and water turnover for short-term space flights (8-14 d). Subjects were 13 male astronauts aged 36-51 y with normal body mass indexes (BMIs). Total energy expenditure (TEE) was determined during both a ground-based period and space flight and compared with the World Health Organization (WHO) calculations of energy requirements and dietary intake. TEE was not different for the ground-based and the space-flight periods (12.40 +/- 2.83 and 11.70 +/- 1.89 MJ/d, respectively), and the WHO calculation using the moderate activity correction was a good predictor of TEE during space flight. During the ground-based period, energy intake and TEE did not differ, but during space flight energy intake was significantly lower than TEE; body weight was also less at landing than before flight. Water turnover was lower during space flight than during the ground-based period (2.7 +/- 0.6 compared with 3.8 +/- 0.5 L/d), probably because of lower fluid intakes and perspiration loss during flight. This study confirmed that the WHO calculation can be used for male crew members' energy requirements during short space flights.

  1. Validation of ACE and OSIRIS ozone and NO2 measurements using ground-based instruments at 80° N

    NASA Astrophysics Data System (ADS)

    Adams, C.; Strong, K.; Batchelor, R. L.; Bernath, P. F.; Brohede, S.; Boone, C.; Degenstein, D.; Daffer, W. H.; Drummond, J. R.; Fogal, P. F.; Farahani, E.; Fayt, C.; Fraser, A.; Goutail, F.; Hendrick, F.; Kolonjari, F.; Lindenmaier, R.; Manney, G.; McElroy, C. T.; McLinden, C. A.; Mendonca, J.; Park, J.-H.; Pavlovic, B.; Pazmino, A.; Roth, C.; Savastiouk, V.; Walker, K. A.; Weaver, D.; Zhao, X.

    2012-05-01

    The Optical Spectrograph and Infra-Red Imager System (OSIRIS) and the Atmospheric Chemistry Experiment (ACE) have been taking measurements from space since 2001 and 2003, respectively. This paper presents intercomparisons between ozone and NO2 measured by the ACE and OSIRIS satellite instruments and by ground-based instruments at the Polar Environment Atmospheric Research Laboratory (PEARL), which is located at Eureka, Canada (80° N, 86° W) and is operated by the Canadian Network for the Detection of Atmospheric Change (CANDAC). The ground-based instruments included in this study are four zenith-sky differential optical absorption spectroscopy (DOAS) instruments, one Bruker Fourier transform infrared spectrometer (FTIR) and four Brewer spectrophotometers. Ozone total columns measured by the DOAS instruments were retrieved using new Network for the Detection of Atmospheric Composition Change (NDACC) guidelines and agree to within 3.2%. The DOAS ozone columns agree with the Brewer spectrophotometers with mean relative differences that are smaller than 1.5%. This suggests that for these instruments the new NDACC data guidelines were successful in producing a homogenous and accurate ozone dataset at 80° N. Satellite 14-52 km ozone and 17-40 km NO2 partial columns within 500 km of PEARL were calculated for ACE-FTS Version 2.2 (v2.2) plus updates, ACE-FTS v3.0, ACE-MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) v1.2 and OSIRIS SaskMART v5.0x ozone and Optimal Estimation v3.0 NO2 data products. The new ACE-FTS v3.0 and the validated ACE-FTS v2.2 partial columns are nearly identical, with mean relative differences of 0.0 ± 0.2% and -0.2 ± 0.1% for v2.2 minus v3.0 ozone and NO2, respectively. Ozone columns were constructed from 14-52 km satellite and 0-14 km ozonesonde partial columns and compared with the ground-based total column measurements. The satellite-plus-sonde measurements agree with the ground-based

  2. Validation of ACE and OSIRIS ozone and NO2 measurements using ground-based instruments at 80° N

    NASA Astrophysics Data System (ADS)

    Adams, C.; Strong, K.; Batchelor, R. L.; Bernath, P. F.; Brohede, S.; Boone, C.; Degenstein, D.; Daffer, W. H.; Drummond, J. R.; Fogal, P. F.; Farahani, E.; Fayt, C.; Fraser, A.; Goutail, F.; Hendrick, F.; Kolonjari, F.; Lindenmaier, R.; Manney, G.; McElroy, C. T.; McLinden, C. A.; Mendonca, J.; Park, J.-H.; Pavlovic, B.; Pazmino, A.; Roth, C.; Savastiouk, V.; Walker, K. A.; Weaver, D.; Zhao, X.

    2012-01-01

    The Optical Spectrograph and Infra-Red Imager System (OSIRIS) and the Atmospheric Chemistry Experiment (ACE) have been taking measurements from space since 2001 and 2003, respectively. This paper presents intercomparisons between ozone and NO2 measured by the ACE and OSIRIS satellite instruments and by ground-based instruments at the Polar Environment Atmospheric Research Laboratory (PEARL), which is located at Eureka, Canada (80° N, 86° W) and is operated by the Canadian Network for the Detection of Atmospheric Change (CANDAC). The ground-based instruments included in this study are four zenith-sky differential optical absorption spectroscopy (DOAS) instruments, one Bruker Fourier transform infrared spectrometer (FTIR) and four Brewer spectrophotometers. Ozone total columns measured by the DOAS instruments were retrieved using new Network for the Detection of Atmospheric Composition Change (NDACC) guidelines and agree to within 3.2%. The DOAS ozone columns agree with the Brewer spectrophotometers with mean relative differences that are smaller than 1.5%. This suggests that for these instruments the new NDACC data guidelines were successful in producing a homogenous and accurate ozone dataset at 80° N. Satellite 14-52 km ozone and 17-40 km NO2 partial columns within 500 km of PEARL were calculated for ACE-FTS Version 2.2 (v2.2) plus updates, ACE-FTS v3.0, ACE-MAESTRO (Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation) v1.2 and OSIRIS SaskMART v5.0x ozone and Optimal Estimation v3.0 NO2 data products. The new ACE-FTS v3.0 and the validated ACE-FTS v2.2 partial columns are nearly identical, with mean relative differences of 0.0 ± 0.2% for ozone and -0.2 ± 0.1% for v2.2 minus v3.3 NO2. Ozone columns were constructed from 14-52 km satellite and 0-14 km ozonesonde partial columns and compared with the ground-based total column measurements. The satellite-plus-sonde measurements agree with the ground-based ozone total

  3. Atmospheric mercury concentrations observed at ground-based monitoring sites globally distributed in the framework of the GMOS network

    NASA Astrophysics Data System (ADS)

    Sprovieri, Francesca; Pirrone, Nicola; Bencardino, Mariantonia; D'Amore, Francesco; Carbone, Francesco; Cinnirella, Sergio; Mannarino, Valentino; Landis, Matthew; Ebinghaus, Ralf; Weigelt, Andreas; Brunke, Ernst-Günther; Labuschagne, Casper; Martin, Lynwill; Munthe, John; Wängberg, Ingvar; Artaxo, Paulo; Morais, Fernando; Barbosa, Henrique de Melo Jorge; Brito, Joel; Cairns, Warren; Barbante, Carlo; Diéguez, María del Carmen; Garcia, Patricia Elizabeth; Dommergue, Aurélien; Angot, Helene; Magand, Olivier; Skov, Henrik; Horvat, Milena; Kotnik, Jože; Read, Katie Alana; Mendes Neves, Luis; Gawlik, Bernd Manfred; Sena, Fabrizio; Mashyanov, Nikolay; Obolkin, Vladimir; Wip, Dennis; Feng, Xin Bin; Zhang, Hui; Fu, Xuewu; Ramachandran, Ramesh; Cossa, Daniel; Knoery, Joël; Marusczak, Nicolas; Nerentorp, Michelle; Norstrom, Claus

    2016-09-01

    Long-term monitoring of data of ambient mercury (Hg) on a global scale to assess its emission, transport, atmospheric chemistry, and deposition processes is vital to understanding the impact of Hg pollution on the environment. The Global Mercury Observation System (GMOS) project was funded by the European Commission (http://www.gmos.eu) and started in November 2010 with the overall goal to develop a coordinated global observing system to monitor Hg on a global scale, including a large network of ground-based monitoring stations, ad hoc periodic oceanographic cruises and measurement flights in the lower and upper troposphere as well as in the lower stratosphere. To date, more than 40 ground-based monitoring sites constitute the global network covering many regions where little to no observational data were available before GMOS. This work presents atmospheric Hg concentrations recorded worldwide in the framework of the GMOS project (2010-2015), analyzing Hg measurement results in terms of temporal trends, seasonality and comparability within the network. Major findings highlighted in this paper include a clear gradient of Hg concentrations between the Northern and Southern hemispheres, confirming that the gradient observed is mostly driven by local and regional sources, which can be anthropogenic, natural or a combination of both.

  4. BigBOSS: The Ground-Based Stage IV BAO Experiment

    SciTech Connect

    Schlegel, David; Bebek, Chris; Heetderks, Henry; Ho, Shirley; Lampton, Michael; Levi, Michael; Mostek, Nick; Padmanabhan, Nikhil; Perlmutter, Saul; Roe, Natalie; Sholl, Michael; Smoot, George; White, Martin; Dey, Arjun; Abraham, Tony; Jannuzi, Buell; Joyce, Dick; Liang, Ming; Merrill, Mike; Olsen, Knut; Salim, Samir

    2009-04-01

    The BigBOSS experiment is a proposed DOE-NSF Stage IV ground-based dark energy experiment to study baryon acoustic oscillations (BAO) and the growth of structure with an all-sky galaxy redshift survey. The project is designed to unlock the mystery of dark energy using existing ground-based facilities operated by NOAO. A new 4000-fiber R=5000 spectrograph covering a 3-degree diameter field will measure BAO and redshift space distortions in the distribution of galaxies and hydrogen gas spanning redshifts from 0.2< z< 3.5. The Dark Energy Task Force figure of merit (DETF FoM) for this experiment is expected to be equal to that of a JDEM mission for BAO with the lower risk and cost typical of a ground-based experiment.

  5. Development of a Portable, Ground-based Ozone Lidar Instrument for Tropospheric Ozone Research and Educational Training

    NASA Technical Reports Server (NTRS)

    Chyba, Thomas; Zemker, Thomas; Fishman, Jack (Technical Monitor)

    1999-01-01

    The objective of this research project is to develop a portable, eye-safe, ground-based ozone lidar instrument specialized for ozone differential absorption lidar (DIAL) measurements in the troposphere. This research project directly supports the goal of NASA's Earth Science Enterprise to understand the distribution and budget of tropospheric ozone (objective 1.5 of the Earth Science Strategic Enterprise Plan, 1998-2002). It can participate in ground validation experiments for TES, a tropospheric ozone satellite mission due to be launched in 2002. It can also be utilized for correlative ground measurements in future GTE (Global Tropospheric Experiment) and space-based ozone lidar missions, such as ORACLE. Multiple ground-based ozone lidar systems would improve the data obtained through current ozone-sonde networks. This prototype instrument could to serve as the basic unit for these and other future monitoring projects requiring multi-instrument networks, such as that proposed for the Global Tropospheric Ozone Project (GTOP). GTOP is currently being formulated by a scientific panel of the International Global Atmospheric Chemistry Project to meet its goal to better understand the processes that control the global distribution of tropospheric ozone. In order for the lidar to be widely deployed in networks, it must be fairly easy to use and maintain as well as being cost-competitive with a ground station launching ozonesondes several times a day. A second 2-year grant to continue this effort with students participating in ground tests and system improvements has been awarded by the Office of Equal Employment Opportunities (OEOP). This project also supports existing NASA lidar missions through its development of advanced, compact lidar technology. Innovations in both transmitters and receivers have been made in this project. Finally, this system could be modified in the future to probe more deeply into the stratosphere. This could be accomplished by increasing the

  6. Deep WFPC2 and Ground-Based Imaging of a Complete Sample of 3C Quasars and Galaxies

    NASA Technical Reports Server (NTRS)

    Ridgway, Susan E.; Stockton, Alan

    1997-01-01

    We present the results of an HST and ground-based imaging study of a complete 3C sample of zeta approx. equal to 1 sources, comprising 5 quasars and 5 radio galaxies. We have observed all of the sample in essentially line-free bands at rest-frame 0.33 micrometers with WFPC2 and in rest-frame 1 micrometer images from the ground; we have also observed most of the sample in narrow-band filters centered on [O II]. We resolve continuum structure around all of our quasars in the high-resolution WFPC2 images, and in four of the five ground-based K' images. All of the quasars have some optical continuum structure that is aligned with the radio axis. In at least 3 of these cases, some of this optical structure is directly coincident with a portion of the radio structure, including optical counterparts to radio jets in 3C212 and 3C245 and an optical counterpart to a radio lobe in 3C2. These are most likely due to optical synchrotron radiation, and the radio and optical spectral indices in the northern lobe of 3C2 are consistent with this interpretation. The fact that we see a beamed optical synchotron component in the quasars but not in the radio galaxies complicates both the magnitude and the alignment comparisons. Nonetheless, the total optical and K' flux densities of the quasar hosts are consistent with those of the radio galaxies within the observed dispersion in our sample. The distributions of K' flux densities of both radio galaxies and quasar hosts exhibit similar mean and dispersion to that found for other radio galaxies at this redshift, and the average host galaxy luminosity is equivalent to, or a little fainter than, L*. The formal determination of the alignment in the optical and infrared in the two subsamples yields no significant difference between the radio galaxy and quasar subsamples, and the quasars 3C 196 and 3C 336 have aligned continuum and emission-line structure that is probably not due to beamed optical synchrotron emission. Very blue and/or edge

  7. PhotoSpec - Ground-based Remote Sensing of Solar-Induced Chlorophyll Fluorescence

    NASA Astrophysics Data System (ADS)

    Grossmann, K.; Frankenberg, C.; Seibt, U.; Hurlock, S. C.; Pivovaroff, A.; Stutz, J.

    2015-12-01

    Solar-Induced Chlorophyll Fluorescence (SIF) emitted from vegetation can be used as a constraint for photosynthetic activity and is now observable on a global scale from space. However, many issues on a leaf-to-canopy scale remain poorly understood, such as influences on the SIF signal of environmental conditions, water stress, or radiation. Here, we report on the development and characterization of a novel ground-based spectrometer system for measuring SIF from natural ecosystems (http://www.kiss.caltech.edu/study/photosynthesis/technology.html). The instrumental set-up, requirements, and measurement technique are based on decades of experience using Differential Optical Absorption Spectroscopy (DOAS), an established method to measure atmospheric trace gases. The instrument consists of three thermally stabilized commercial spectrometers that are linked to a 2D scanning telescope unit via optical fiber bundles. The spectrometers cover an SIF retrieval wavelength range at high spectral resolution (670 - 780 nm, 0.1 nm FWHM), but also provide moderate resolution spectra (400 - 800 nm, 1.5 nm FWHM) in order to retrieve vegetation indices and the photochemical reflectance index (PRI). In addition to the instrumental set-up, we will show initial results of test and field measurements with the new instrument that examine the diurnal cycle of the SIF signal of different California native and non-native plants and its correlation with CO2 fluxes. Observations were made under different environmental conditions, variable water and nutrient stress, and with different viewing geometries. We also used concurrent observations by a photosynthetically active radiation (PAR) sensor and a portable chlorophyll fluorometer (PAM) to link the SIF signal to plant metabolism and carbon cycling under a range of environmental conditions.

  8. Effects of Leisure Education Programme Including Sportive Activities on Perceived Freedom in Leisure of Adolescents with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Ertuzun, Ezgi

    2015-01-01

    The objective of this experimental study is to determine the effect of leisure education programme including sportive activities on the perceived freedom in leisure of adolescents with mild intellectual disabilities. The research was designed with an experimental group (n = 37) and a control group (n = 34), and was conducted among a total of 71…

  9. 25 CFR 170.623 - How are IRR Program projects and activities included in a self-governance agreement?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... other information required under 25 CFR 1000 subpart K. ... self-governance agreement? 170.623 Section 170.623 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE... self-governance agreement? To include an IRR Program project or activity in a self-governance...

  10. 25 CFR 170.623 - How are IRR Program projects and activities included in a self-governance agreement?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... other information required under 25 CFR 1000 subpart K. ... self-governance agreement? 170.623 Section 170.623 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE... self-governance agreement? To include an IRR Program project or activity in a self-governance...

  11. 25 CFR 170.623 - How are IRR Program projects and activities included in a self-governance agreement?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... other information required under 25 CFR 1000 subpart K. ... self-governance agreement? 170.623 Section 170.623 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE... self-governance agreement? To include an IRR Program project or activity in a self-governance...

  12. 25 CFR 170.623 - How are IRR Program projects and activities included in a self-governance agreement?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... other information required under 25 CFR 1000 subpart K. ... self-governance agreement? 170.623 Section 170.623 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE... self-governance agreement? To include an IRR Program project or activity in a self-governance...

  13. 25 CFR 170.623 - How are IRR Program projects and activities included in a self-governance agreement?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... other information required under 25 CFR 1000 subpart K. ... self-governance agreement? 170.623 Section 170.623 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE... self-governance agreement? To include an IRR Program project or activity in a self-governance...

  14. A lipid chemotactic factor from anaerobic coryneform bacteria including Corynebacterium parvum with activity for macrophages and monocytes.

    PubMed Central

    Russell, R J; McInroy, R J; Wilkinson, P C; White, R G

    1976-01-01

    A lipid with chemoattractant (chemotactic) activity for mouse and guinea-pig macrophages and for human blood monocytes is released by anaerobic coryneform bacteria (including Corynebacterium parvum). The active lipid is associated with fibrillar structures which lie on the outside of the bacterial cell and are released spontaneously during growth. The lipid can also be extracted easily by a number of methods. The fibrils are loosely associated with a capsule-like structure composed largely of polysaccharide. Purification of the active lipid was achieved by chloroform-methanol extraction of the whole organisms yielding a chloroform-soluble fraction attracting mononuclear phagocytes at concentrations around 10 microgram/ml. The infra-red spectrum of this material showed lipid but no peptide or sugar. Thin-layer chromatography yielded twelve spots of which three had chemoattractant properties. The most active of these gave staining reactions consistent with the presence of phospholipid, the other two probably contained free fatty acids and triglycerides. Thin-layer electrophoresis also yielded an active phosphorus-containing spot. Saturated fatty acids of chain lengths found in the anaerobic coryne forms had weak monocyte-attractant activity. As the active material was progressively purified, its activity as a monocyte attractant weakened. Images Figure 2 Figure 3 Figure 4 PMID:1027716

  15. Consistent interpretation of ground based and GOME BrO slant column data

    NASA Astrophysics Data System (ADS)

    Mueller, R. W.; Bovensmann, H.; Kaiser, J. W.; Richter, A.; Rozanov, A.; Wittrock, F.; Burrows, J. P.

    Model computations of slant column densities (SCD) enable the comparison between ground based and satellite based absorption measurements of scattered light and are therefore a good basis to investigate the presence of tropospheric BrO amounts. In this study ground based zenith sky and GOME nadir measurements of BrO SCD are compared with simulations for the 19-21 March 1997 at Ny-Ålesund. The vertical columns of tropospheric BrO amounts are estimated to be in the range 4 ±0.8 ∗ 10 13 [molecules/cm 2] for the investigated period and location.

  16. Behavior of stem cells under outer-space microgravity and ground-based microgravity simulation.

    PubMed

    Zhang, Cui; Li, Liang; Chen, Jianling; Wang, Jinfu

    2015-06-01

    With rapid development of space engineering, research on life sciences in space is being conducted extensively, especially cellular and molecular studies on space medicine. Stem cells, undifferentiated cells that can differentiate into specialized cells, are considered a key resource for regenerative medicine. Research on stem cells under conditions of microgravity during a space flight or a ground-based simulation has generated several excellent findings. To help readers understand the effects of outer space and ground-based simulation conditions on stem cells, we reviewed recent studies on the effects of microgravity (as an obvious environmental factor in space) on morphology, proliferation, migration, and differentiation of stem cells.

  17. Ground-based determination of atmospheric radiance for correction of ERTS-1 data

    NASA Technical Reports Server (NTRS)

    Peacock, K.

    1974-01-01

    A technique is described for estimating the atmospheric radiance observed by a downward sensor (ERTS) using ground-based measurements. A formula is obtained for the sky radiance at the time of the ERTS overpass from the radiometric measurement of the sky radiance made at a particular solar zenith angle and air mass. A graph illustrates ground-based sky radiance measurements as a function of the scattering angle for a range of solar air masses. Typical values for sky radiance at a solar zenith angle of 48 degrees are given.

  18. A comparison of airborne and ground-based radar observations with rain gages during the CaPE experiment

    NASA Technical Reports Server (NTRS)

    Satake, Makoto; Short, David A.; Iguchi, Toshio

    1992-01-01

    The vicinity of KSC, where the primary ground truth site of the Tropical Rainfall Measuring Mission (TRMM) program is located, was the focal point of the Convection and Precipitation/Electrification (CaPE) experiment in Jul. and Aug. 1991. In addition to several specialized radars, local coverage was provided by the C-band (5 cm) radar at Patrick AFB. Point measurements of rain rate were provided by tipping bucket rain gage networks. Besides these ground-based activities, airborne radar measurements with X- and Ka-band nadir-looking radars on board an aircraft were also recorded. A unique combination data set of airborne radar observations with ground-based observations was obtained in the summer convective rain regime of central Florida. We present a comparison of these data intending a preliminary validation. A convective rain event was observed simultaneously by all three instrument types on the evening of 27 Jul. 1991. The high resolution aircraft radar was flown over convective cells with tops exceeding 10 km and observed reflectivities of 40 to 50 dBZ at 4 to 5 km altitude, while the low resolution surface radar observed 35 to 55 dBZ echoes and a rain gage indicated maximum surface rain rates exceeding 100 mm/hr. The height profile of reflectivity measured with the airborne radar show an attenuation of 6.5 dB/km (two way) for X-band, corresponding to a rainfall rate of 95 mm/hr.

  19. Gaia-FUN-SSO: a network for ground-based follow-up observations of Solar System Objects

    NASA Astrophysics Data System (ADS)

    Thuillot, W.; Carry, B.; Berthier, J.; David, P.; Hestroffer, D.; Rocher, P.

    2014-12-01

    Gaia-FUN-SSO (shortly described at https://www.imcce.fr/gaia-fun-sso/) is a ground-based network of observatories set up in the framework of the Gaia consortium (DPAC-CU4) for the follow-up of critical Solar System objects to be discovered from space by the Gaia satellite. Its goal is to retrieve from the ground a newly detected object and to complement the astrometry measurements carried out by Gaia to determine its heliocentric orbit. Data from both Gaia and the ground-based network will be sent to the Minor Planet Center, used to determine the orbit and thus to update the database of minor planet orbits, which is subsequently used by Gaia for the identification of moving objects. We are expecting the detection of many asteroids, mainly from the main belt, and also new near-Earth objects (NEO) at low solar elongation. Owing to the specific conditions of Gaia observations, we even expect the detection of objects whose orbit is fully contained within Earth's orbit (called inner-Earth or Atira asteroids). Several training campaigns have already been organized with the network and it is now able to enter in an operating mode when alerts will be triggered. We describe here the expected number of discoveries, the network, its activity, and the data processing of the central node of the network set in place for the operating mode.

  20. A comparison of airborne and ground-based radar observations with rain gages during the CaPE experiment

    NASA Technical Reports Server (NTRS)

    Satake, Makoto; Short, David A.; Iguchi, Toshio

    1992-01-01

    The vicinity of KSC, where the primary ground truth site of the Tropical Rainfall Measuring Mission (TRMM) program is located, was the focal point of the Convection and Precipitation/Electrification (CaPE) experiment in July and Aug. 1991. In addition to several specialized radars, local coverage was provided by the C-band (5 cm) radar at Patrick AFB. Point measurements of rain rate were provided by tipping bucket rain gage networks. Besides these ground-based activities, airborne radar measurements with X- and Ka-band nadir-looking radars on board an aircraft were also recorded. A unique combination data set of airborne radar observations with ground-based observations was obtained in the summer convective rain regime of central Florida. We present a comparison of these data intending a preliminary validation. A convective rain event was observed simultaneously by all three instrument types on the evening of 27 July 1991. The high resolution aircraft radar was flown over convective cells with tops exceeding 10 km and observed reflectivities of 40 to 50 dBZ at 4 to 5 km altitude, while the low resolution surface radar observed 35 to 55 dBZ echoes and a rain gage indicated maximum surface rain rates exceeding 100 mm/hr. The height profile of reflectivity measured with the airborne radar show an attenuation of 6.5 dB/km (two way) for X-band, corresponding to a rainfall rate of 95 mm/hr.

  1. Aerosol optical properties over the Svalbard region of Arctic: ground-based measurements and satellite remote sensing

    NASA Astrophysics Data System (ADS)

    Gogoi, Mukunda M.; Babu, S. Suresh

    2016-05-01

    In view of the increasing anthropogenic presence and influence of aerosols in the northern polar regions, long-term continuous measurements of aerosol optical parameters have been investigated over the Svalbard region of Norwegian Arctic (Ny-Ålesund, 79°N, 12°E, 8 m ASL). This study has shown a consistent enhancement in the aerosol scattering and absorption coefficients during spring. The relative dominance of absorbing aerosols is more near the surface (lower single scattering albedo), compared to that at the higher altitude. This is indicative of the presence of local anthropogenic activities. In addition, long-range transported biomass burning aerosols (inferred from the spectral variation of absorption coefficient) also contribute significantly to the higher aerosol absorption in the Arctic spring. Aerosol optical depth (AOD) estimates from ground based Microtop sun-photometer measurements reveals that the columnar abundance of aerosols reaches the peak during spring season. Comparison of AODs between ground based and satellite remote sensing indicates that deep blue algorithm of Moderate Resolution Imaging Spectroradiometer (MODIS) retrievals over Arctic snow surfaces overestimate the columnar AOD.

  2. Model Predictions and Ground-based Observations for Jupiter's Magnetospheric Environment: Application to the JUICE and Juno Missions

    NASA Astrophysics Data System (ADS)

    Achilleos, Nicholas; Guio, Patrick; Arridge, Christopher S.; Ray, Licia C.; Yates, Japheth N.; Fossey, Stephen J.; Savini, Giorgio; Pearson, Mick; Fernando, Nathalie; Gerasimov, Roman; Murat, Thomas

    2016-10-01

    The advent of new missions to the Jovian system such as Juno (recently arrived) and JUICE (scheduled for 2022 launch) makes timely the provision of model-based predictions for the physical conditions to be encountered by these spacecraft; as well as the planning of simultaneous, ground-based observations of the Jovian system.Using the UCL Jovian magnetodisc model, which calculates magnetic field and plasma distributionsaccording to Caudal's (1986) force-balance formalism, we provide predictions of the following quantities along representative Juno / JUICE orbits through the middle magnetosphere: (i) Magnetic field strength and direction; (ii) Density and / or pressure of the 'cold' and 'hot' particle populations; (iii) Plasma angular velocity.The characteristic variation in these parameters is mainly influenced by the periodic approaches towards and recessions from the magnetodisc imposed on the 'synthetic spacecraft' by the planet's rotating, tilteddipole field. We also include some corresponding predictions for ionospheric / thermospheric conditions at the magnetic footpoint of the spacecraft, using the JASMIN model (Jovian Atmospheric Simulatorwith Magnetosphere, Ionosphere and Neutrals).We also present preliminary imaging results from 'IoSpot', a planned, ground-based programme of observations based at the University College London Observatory (UCLO) which targets ionized sulphur emissions from the Io plasma torus. Such programmes, conducted simultaneously with the above missions, will provide valuable context for the overall physical conditions within the Jovian magnetosphere, for which Io's volcanoes are the principal source of plasma.

  3. Interannaul variations of the vertical and their possible influence on the star catalogs derived from ground-based astrometric observations

    NASA Astrophysics Data System (ADS)

    Li, Z. X.

    The efforts at Shanghai Observatory since 1991, in response to the Resolution of IAU Comm.19: "Applications of optical astrometry time and latitude programs", is described in the paper, especially the studies concerned with the interannual variations of the vertical and their influence on the astronomical studies. It is clear now that there is a component of the order 0.01 - 0.02" on an interannual time scale in latitude residuals which is correlated with geophysical phenomena on the Earth. A recent study has confirmed that the component discovered is actually the variation of the vertical, related to ground-based observation in astronomy. So, it should be emphasized now that the variation of the vertical is significant enough to be considered in astronomy from now on. Its influence on the past studies, including the star catalogs already published and the ERP before 1980 when optical astrometry observations were still used, should be studied in the future. In comparing the HIPPARCOS catalog with those derived by the past observations, we should keep in mind the existence of this error in an astrometric observation and its influence on the star catalogs and other results derived from ground-based astrometric observations.

  4. GravityCam: ground-based wide-field high-resolution imaging and high-speed photometry

    NASA Astrophysics Data System (ADS)

    Dominik, Martin; Mackay, Craig; Steele, Iain; Snodgrass, Colin; Hirsch, Michael; Gråe Jørgensen, Uffe; Hundertmark, Markus; Rebolo, Rafael; Horne, Keith; Bridle, Sarah; Sicardy, Bruno; Bramich, Daniel; Alsubai, Khalid

    2015-12-01

    The image blurring by the Earth's atmosphere generally poses a substantial limitation to ground-based observations. While opportunities in space are scarce, lucky imaging can correct over a much larger patch of sky and with much fainter reference stars. We propose the first of a new kind of versatile instruments, "GravityCam", composed of ~100 EMCCDs, that will open up two entirely new windows to ground-based astronomy: (1) wide-field high-resolution imaging, and (2) wide-field high-speed photometry. Potential applications include (a) a gravitational microlensing survey going 4 magnitudes deeper than current efforts, and thereby gaining a factor 100 in mass at the same sensitivity, which means probing down to Lunar mass or even below, (b) extra-solar planet hunting via transits in galactic bulge fields, with high time resolution well-suited for transit timing variation studies, (c) variable stars in crowded fields, with sensitivity to very short periods, (d) asteroseismology with many bright stars in one pointing, (e) serendipitous occultations of stars by small solar system bodies, giving access to the small end of the Kuiper Belt size distribution and potentially leading to the first detection of true Oort cloud objects, while predicted occultations at high time resolution can reveal atmospheres, satellites, or rings, (f) general data mining of the high-speed variable sky (down to 40 ms cadence).

  5. Evaluation of Chemistry-Climate Model Results using Long-Term Satellite and Ground-Based Data

    NASA Technical Reports Server (NTRS)

    Stolarski, Richard S.

    2005-01-01

    Chemistry-climate models attempt to bring together our best knowledge of the key processes that govern the composition of the atmosphere and its response to changes in forcing. We test these models on a process by process basis by comparing model results to data from many sources. A more difficult task is testing the model response to changes. One way to do this is to use the natural and anthropogenic experiments that have been done on the atmosphere and are continuing to be done. These include the volcanic eruptions of El Chichon and Pinatubo, the solar cycle, and the injection of chlorine and bromine from CFCs and methyl bromide. The test of the model's response to these experiments is their ability to produce the long-term variations in ozone and the trace gases that affect ozone. We now have more than 25 years of satellite ozone data. We have more than 15 years of satellite and ground-based data of HC1, HN03, and many other gases. I will discuss the testing of models using long-term satellite data sets, long-term measurements from the Network for Detection of Stratospheric Change (NDSC) , long-term ground-based measurements of ozone.

  6. Lightning flash detection in Venus and Jupiter with spacecraft and ground-based telescope

    NASA Astrophysics Data System (ADS)

    Takahashi, Yukihiro; Watanabe, Shigeto; Yamashita, Kozo; Sato, Mitsuteru

    2016-07-01

    operation of UVI, ultraviolet imager, on board Akatsuki, in order to capture the lightning flash, which might also happen in the ultraviolet range by CO2. It has been suggested for a decade that thunderstorms in Jupiter's atmosphere take important roles not only in the investigation of meteorology, which determines the large scale structures such as belt/zone and big ovals, but also in probing the water abundance of the deep atmosphere, which is crucial to constrain the behavior of volatiles in early solar system. Here we suggest making observation of thunderstorm activity using lightning flash detection, which was already confirmed by some spacecraft observation, and cloud imagery with JUICE spacecraft and ground-based telescopes. Observing H Balmer Alpha line (656.3nm), we could estimate the activities of thunderstorms quantitatively, which enables us to investigate the mechanism of large structure formation.

  7. Initial Results from the DEEPWAVE Airborne and Ground-Based Measurement Program in New Zealand in 2014

    NASA Astrophysics Data System (ADS)

    Fritts, Dave; Smith, Ron; Taylor, Mike; Doyle, Jim; Eckermann, Steve; Dörnbrack, Andreas; Rapp, Markus; Williams, Biff; Bossert, Katrina; Pautet, Dominique

    2015-04-01

    The deep-propagating gravity wave experiment (DEEPWAVE) was performed on and over New Zealand, Tasmania, the Tasman Sea, and the Southern Ocean with core airborne measurements extending from 5 June to 21 July 2014 and supporting ground-based measurements beginning in late May and extending beyond the airborne component. DEEPWAVE employed two aircraft, the NSF/NCAR GV and the German DLR Falcon. The GV carried the standard flight-level instruments, dropsondes, and the Microwave Temperature Profiler (MTP). It also hosted new airborne lidar and imaging instruments built specifically to allow quantification of gravity waves (GWs) from sources at lower altitudes (e.g., orography, convection, jet streams, fronts, and secondary GW generation) throughout the stratosphere and into the mesosphere and lower thermosphere (MLT). The new GV lidars included a Rayleigh lidar measuring atmospheric density and temperature from ~20-60 km and a sodium resonance lidar measuring sodium density and temperature at ~75-100 km. An airborne Advanced Mesosphere Temperature Mapper (AMTM) was also developed for the GV, and together with additional IR "wing" cameras, imaged the OH airglow temperature and/or intensity fields extending ~900 km across the GV flight track. The DLR Falcon was equipped with its standard flight-level instruments and an aerosol Doppler lidar able to measure radial winds below the Falcon where aerosol backscatter was sufficient. Additional ground-based instruments included a 449 MHz boundary layer radar, balloons at multiple sites, two ground-based Rayleigh lidars, a second ground-based AMTM, a Fabry Perot interferometer measuring winds and temperatures at ~87 and 95 km, and a meteor radar measuring winds from ~80-100 km. DEEPWAVE performed 26 GV flights, 13 Falcon flights, and an extensive series of ground-based measurements whether or not the aircraft were flying. Together, these observed many diverse cases of GW forcing, propagation, refraction, and dissipation

  8. Ground-based GPS monitoring at the Lusi eruption site and external perturbations.

    NASA Astrophysics Data System (ADS)

    Husein, Alwi; Mazzini, Adriano; Hadi, Soffian; Santosa, Bagus; Charis, Muhammad; Irawan, Dwinata

    2016-04-01

    The Indonesian Lusi mud eruption started in May 2006 and since then has been continuously spewing hot mud over a surface of 7 km2 that is today framed by high containment dams. The shape of the eruption site constantly evolved during the last 9.5 years. After an initial cone-shaped morphology, the original ground level has been characterized by an overall progressive subsidence, typical at eruption sites, compensated by the continuous eruption of boiling mud breccia. Numerous external factors appear to influence the evolution of the Lusi morphology and its activity. Of particular interest is the interaction between the frequent seismicity, the activity of the neighboring volcanic arcs, the Watukosek fault system that intersects Lusi, that in turn alter the eruption activity and posture. In order to study the evolution of the Lusi system, we continuously monitor the area using a GPS ground-based method. The investigation is conducted ombining the data from a base station located ~5 km to the south of Lusi, coupled with several secondary benchmark stations scatterred just around the crater and the embankment that frames the eruption site. These data are complemented by rover GPS stations connected to the system. About 400-1000 point measurements are collected during each survey depending on the condition of the mud terrain. The collected data allows monitoring the evolution and the displacements occurring around the eruption site as well as the changes in mud erupted volumes and the related variations in flow rate. Results reveal that the ongoing subsidence and other significant morphological changes occurring at Lusi site are directly correlated with recorded seismic events as well as regional volcanic activity at various sites. During such events the normal gradual collapse trend is reversed and are observed lateral and/or vertical elevation increases resulting in several centimeters of dislocation during the analyzed time frame. This monitoring reveals that even

  9. Validation of stratospheric temperature profiles from a ground-based microwave radiometer with other techniques

    NASA Astrophysics Data System (ADS)

    Navas, Francisco; Kämpfer, Niklaus; Haefele, Alexander; Keckhut, Philippe; Hauchecorne, Alain

    2016-04-01

    Vertical profiles of atmospheric temperature trends has become recognized as an important indicator of climate change, because different climate forcing mechanisms exhibit distinct vertical warming and cooling patterns. For example, the cooling of the stratosphere is an indicator for climate change as it provides evidence of natural and anthropogenic climate forcing just like surface warming. Despite its importance, our understanding of the observed stratospheric temperature trend and our ability to test simulations of the stratospheric response to emissions of greenhouse gases and ozone depleting substances remains limited. One of the main reason is because stratospheric long-term datasets are sparse and obtained trends differ from one another. Different techniques allow to measure stratospheric temperature profiles as radiosonde, lidar or satellite. The main advantage of microwave radiometers against these other instruments is a high temporal resolution with a reasonable good spatial resolution. Moreover, the measurement at a fixed location allows to observe local atmospheric dynamics over a long time period, which is crucial for climate research. This study presents an evaluation of the stratospheric temperature profiles from a newly ground-based microwave temperature radiometer (TEMPERA) which has been built and designed at the University of Bern. The measurements from TEMPERA are compared with the ones from other different techniques such as in-situ (radiosondes), active remote sensing (lidar) and passive remote sensing on board of Aura satellite (MLS) measurements. In addition a statistical analysis of the stratospheric temperature obtained from TEMPERA measurements during four years of data has been performed. This analysis evidenced the capability of TEMPERA radiometer to monitor the temperature in the stratosphere for a long-term. The detection of some singular sudden stratospheric warming (SSW) during the analyzed period shows the necessity of these

  10. Comparisons of Reflectivities from the TRMM Precipitation Radar and Ground-Based Radars

    NASA Technical Reports Server (NTRS)

    Wang, Jianxin; Wolff, David B.

    2008-01-01

    Given the decade long and highly successful Tropical Rainfall Measuring Mission (TRMM), it is now possible to provide quantitative comparisons between ground-based radars (GRs) with the space-borne TRMM precipitation radar (PR) with greater certainty over longer time scales in various tropical climatological regions. This study develops an automated methodology to match and compare simultaneous TRMM PR and GR reflectivities at four primary TRMM Ground Validation (GV) sites: Houston, Texas (HSTN); Melbourne, Florida (MELB); Kwajalein, Republic of the Marshall Islands (KWAJ); and Darwin, Australia (DARW). Data from each instrument are resampled into a three-dimensional Cartesian coordinate system. The horizontal displacement during the PR data resampling is corrected. Comparisons suggest that the PR suffers significant attenuation at lower levels especially in convective rain. The attenuation correction performs quite well for convective rain but appears to slightly over-correct in stratiform rain. The PR and GR observations at HSTN, MELB and KWAJ agree to about 1 dB on average with a few exceptions, while the GR at DARW requires +1 to -5 dB calibration corrections. One of the important findings of this study is that the GR calibration offset is dependent on the reflectivity magnitude. Hence, we propose that the calibration should be carried out using a regression correction, rather than simply adding an offset value to all GR reflectivities. This methodology is developed towards TRMM GV efforts to improve the accuracy of tropical rain estimates, and can also be applied to the proposed Global Precipitation Measurement and other related activities over the globe.

  11. Soil moisture anomalies and convection: investigation using ground-based measurements at US Southern Great Plains

    NASA Astrophysics Data System (ADS)

    Zhang, Y.

    2015-12-01

    Soil moisture is one of the key factors modulating the atmospheric boundary layer and thus the climate system. In this study, we use ground-based measurements to investigate the mechanism by which soil moisture anomalies affect clouds and precipitation. From decade-long warm season observation by Department of Energy Atmospheric Radiation Measurement at Southern Great Plains, we carefully select daytime weather regimes that are strongly coupled with land-surface processes such as clear-sky dry convection days, forced and active non-precipitating shallow cumuli days, and late-afternoon deep convective raining days (Zhang and Klein, 2010 and 2013). Based on this framework, we statistically assess: 1) the differences in soil moisture and surface heterogeneity between different convective regimes; and 2) the variances of the associated effects on surface and boundary layer meteorological conditions inside each convective regime. A specific question will be: under different soil moisture conditions, e.g. wet/dry, which convective weather regime will be favored and how this is related to large-scale environmental factors, such as free-troposphere stability and humidity? The answer to this question will improve our understanding of how soil moisture impacts boundary layer turbulence and thermodynamics, and influences the convection triggering and maintenance and their feedbacks on soil moisture, thus establish a link between soil moisture and convection at the process level. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-675737

  12. Comparing ECMWF UV processor and aerosol scheme with ground-based measurements

    NASA Astrophysics Data System (ADS)

    Cesnulyte, Vaida; Lindfors, Anders V.; Pitkänen, Mikko R. A.; Lehtinen, Kari E. J.; Morcrette, Jean-Jacques; Benedetti, Angela; Arola, Antti

    2014-05-01

    The ECMWF (European Centre for Medium-Range Weather Forecasts) system offers an alternative approach to provide global UV data products which can support environmental assessments of UV radiation, biological and photochemical impact studies, and to contribute to the global climatology of UV radiation. The ECMWF model includes the effect of aerosols as a part of its radiation transfer calculations. During the first steps of the development of the UV processor, an aerosol climatology was used. In the latest version, however, prognostic aerosols have been coupled with the UV processor which, as a result, provides information about the global UV radiation and can be an alternative to satellite observations. The aim of this study is to evaluate the ECMWF UV/aerosol optical depth (AOD) model against ground-based measurements and further develop the UV Processor. The data used for the study is MACC reanalysis AOD and UV intensities for the period 2003-2006. The evaluation was done by comparing the model data with measurements from EUVDB (European UV Database), NSF (National Science Foundation) and AERONET (Aerosol Robotic Network). The ECMWF shortwave radiative transfer scheme provides the UV radiation at the surface for wavelengths between 280 and 400nm. However, for this analysis, the wavelength ranges 290-320 (UVB) and 320-340 (UVA) were used. This is the first time when a global model such as the ECMWF is evaluated for the performance of AOD at a UV wavelength. The results show that the MACC system generally provides a good representation of the AOD on a monthly basis, showing a realistic seasonal cycle. The model is mostly able to capture major dust load events and also the peak months of biomass burning correctly. When comparing hourly AOD values, the model-measurement agreement is better for biomass burning and dust sites than for urban sites, with an average correlation coefficient around 0.90 for biomass burning sites, around 0.77 for dust sites, and below 0

  13. Colour polymeric paints research under atomic oxygen in flight and ground-based experiments

    NASA Astrophysics Data System (ADS)

    Chernik, V. N.; Naumov, S. F.; Sokolova, S. P.; Gerasimova, T. I.; Kurilyonok, A. O.; Poruchikova, Ju. V.; Novikova, V. A.

    2003-09-01

    Three types of colour coatings were tested to atomic oxygen resistance on ground-based and in-flight experiments. The epoxy enamels colouring change and significant mass losses are observed. The effect of atomic oxygen on silicone enamels almost does not change their colouring and mass. Protection of the epoxy enamels by a layer of silicone varnish increases paints resistance.

  14. Evaluation of rotating-cylinder and piston-cylinder reactors for ground-based emulsion polymerization

    NASA Technical Reports Server (NTRS)

    Vanderhoff, J. W.; El-Aasser, M. S.

    1987-01-01

    The objectives of this program are to apply ground-based emulsion polymerization reactor technology to improve the production of: monodisperse latex particles for calibration standards, chromatographic separation column packing, and medical research; and commercial latexes such as those used for coatings, foams, and adhesives.

  15. Low Power Ground-Based Laser Illumination for Electric Propulsion Applications

    NASA Technical Reports Server (NTRS)

    Lapointe, Michael R.; Oleson, Steven R.

    1994-01-01

    A preliminary evaluation of low power, ground-based laser powered electric propulsion systems is presented. A review of available and near-term laser, photovoltaic, and adaptive optic systems indicates that approximately 5-kW of ground-based laser power can be delivered at an equivalent one-sun intensity to an orbit of approximately 2000 km. Laser illumination at the proper wavelength can double photovoltaic array conversion efficiencies compared to efficiencies obtained with solar illumination at the same intensity, allowing a reduction in array mass. The reduced array mass allows extra propellant to be carried with no penalty in total spacecraft mass. The extra propellant mass can extend the satellite life in orbit, allowing additional revenue to be generated. A trade study using realistic cost estimates and conservative ground station viewing capability was performed to estimate the number of communication satellites which must be illuminated to make a proliferated system of laser ground stations economically attractive. The required number of satellites is typically below that of proposed communication satellite constellations, indicating that low power ground-based laser beaming may be commercially viable. However, near-term advances in low specific mass solar arrays and high energy density batteries for LEO applications would render the ground-based laser system impracticable.

  16. Plant diversity to support humans in a CELSS ground-based demonstrator

    NASA Technical Reports Server (NTRS)

    Howe, J. M.; Hoff, J. E.

    1982-01-01

    Factors that influence the human nutritional requirements envisioned in a controlled ecological life support system ground-based demonstrator and on bioavailability experiments of Ca, Fe and Zn are discussed. The interrelationhip of protein and magnesium on Ca retention is also described.

  17. Ground-Based Remote Sensing of Water-Stressed Crops: Thermal and Multispectral Imaging

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ground-based methods of remote sensing can be used as ground-truthing for satellite-based remote sensing, and in some cases may be a more affordable means of obtaining such data. Plant canopy temperature has been used to indicate and quantify plant water stress. A field research study was conducted ...

  18. Ground-based thermal and multispectral imaging of limited irrigation crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ground-based methods of remote sensing can be used as ground-truth for satellite-based remote sensing, and in some cases may be a more affordable means of obtaining such data. Plant canopy temperature has been used to indicate and quantify plant water stress. A field research study was conducted in ...

  19. Ground-Based Navigation and Dispersion Analysis for the Orion Exploration Mission 1

    NASA Technical Reports Server (NTRS)

    D' Souza, Christopher; Holt, Greg; Zanetti, Renato; Wood, Brandon

    2016-01-01

    This paper presents the Orion Exploration Mission 1 Linear Covariance Analysis for the DRO mission using ground-based navigation. The Delta V statistics for each maneuver are presented. In particular, the statistics of the lunar encounters and the Entry Interface are presented.

  20. Analysis of global cloudiness. 2: Comparison of ground-based and satellite-based cloud climatologies

    SciTech Connect

    Mokhov, I.I.; Schlesinger, M.E. |

    1994-08-01

    Cloud climatologies are developed and intercompared for International Satellite Cloud Climatology Project (ISCCO) (1983-1988), Meteor I (1971-1980), Meteor II (1979-1988), and Nimbus 7 (1979-1985) satellite observations, and for Berlyand and Strokina (1975, 1980) and Warren et al. (1986, 1988) ground-based observations. The satellite annual-mean, global- mean cloudiness, 0.57 +/- 0.05, is less than the ground-based value, 0.61 +/- 0.01, predominantly because of the low value for Nimbus 7. There is agreement between the satellite means of ISCCP, 0.62, and Meteor II, 0.61, and the ground-based means of Warren et al., 0.62, and Berlyand and Strokina, 0.60. Each satellite- and ground-based climatology shows that the hemispheric- mean cloudiness is larger in summer than that in winter in both the northern and southern hemispheres. Excluding Nimbus 7 observations, the zonal- mean cloudiness distributions for January, July, and July minus January display reasonably good agreement between 60 deg S and 60 deg N. In polar latitudes there is significant disagreement among the different climatologies, even in the sign of cloudiness changes from winter to summer. This evinces the need for special cloudiness experiments in polar regions, particularly in winter and summer.

  1. Simulation of the imaging quality of ground-based telescopes affected by atmospheric disturbances

    NASA Astrophysics Data System (ADS)

    Ren, Yubin; Kou, Songfeng; Gu, Bozhong

    2014-08-01

    Ground-based telescope imaging model is developed in this paper, the relationship between the atmospheric disturbances and the ground-based telescope image quality is studied. Simulation of the wave-front distortions caused by atmospheric turbulences has long been an important method in the study of the propagation of light through the atmosphere. The phase of the starlight wave-front is changed over time, but in an appropriate short exposure time, the atmospheric disturbances can be considered as "frozen". In accordance with Kolmogorov turbulence theory, simulating atmospheric disturbances of image model based on the phase screen distorted by atmospheric turbulences is achieved by the fast Fourier transform (FFT). Geiger mode avalanche photodiode array (APD arrays) model is used for atmospheric wave-front detection, the image is achieved by inversion method of photon counting after the target starlight goes through phase screens and ground-based telescopes. Ground-based telescope imaging model is established in this paper can accurately achieve the relationship between the quality of telescope imaging and monolayer or multilayer atmosphere disturbances, and it is great significance for the wave-front detection and optical correction in a Multi-conjugate Adaptive Optics system (MCAO).

  2. Evaluation of Radar Vegetation Indices for Vegetation Water Content Estimation Using Data from a Ground-Based SMAP Simulator

    NASA Technical Reports Server (NTRS)

    Srivastava, Prashant K.; O'Neill, Peggy; Cosh, Michael; Lang, Roger; Joseph, Alicia

    2015-01-01

    Vegetation water content (VWC) is an important component of microwave soil moisture retrieval algorithms. This paper aims to estimate VWC using L band active and passive radar/radiometer datasets obtained from a NASA ground-based Soil Moisture Active Passive (SMAP) simulator known as ComRAD (Combined Radar/Radiometer). Several approaches to derive vegetation information from radar and radiometer data such as HH, HV, VV, Microwave Polarization Difference Index (MPDI), HH/VV ratio, HV/(HH+VV), HV/(HH+HV+VV) and Radar Vegetation Index (RVI) are tested for VWC estimation through a generalized linear model (GLM). The overall analysis indicates that HV radar backscattering could be used for VWC content estimation with highest performance followed by HH, VV, MPDI, RVI, and other ratios.

  3. Diagnosis of Magnetotail Drivers for Ionospheric Electrodynamics Using Networks of Ground-based Magnetometers

    NASA Astrophysics Data System (ADS)

    Mann, I. R.; Rae, I. J.; Murphy, K.; Milling, D. K.; Russell, C. T.; Angelopoulos, V.

    2009-05-01

    One of the most important problems in solar-terrestrial physics concerns understanding the response of the ionosphere to a variety of physical drivers from the magnetotail. In particular, determining the ionospheric response to magnetotail disturbances such as current disruptions and Earthward-directed bursty bulk flows is key to understanding the causal sequence of events during substorms. We present a series of case studies using data from combined networks of magnetometers in the Canadian sector, including those from CARISMA (www.carisma.ca) and the THEMIS ground-based observatory (GBO) network and supporting arrays, to examine the current response in the ionosphere to substorm expansion phase onset. These analyses highlight the importance of extensive magnetometer coverage in order to correctly identify and characterise the initiation and temporal dynamics of substorm-time ionospheric electrodynamics and current systems. We show how magnetometer data can be used to locate and time the onset of substorms using Pi1 data, and further develop a magnetic disturbance diagnostic which may distinguish between tail drivers. We suggest that the structure of the resulting current systems may enable these processes to be distinguished using a new set of local magnetometer derived disturbance indices. We suggest forms for these new ionospheric disturbance indices, as an extension to the traditional AE, AL and AU indices. We show how these diagnostics can provide important input into substorm studies, especially in partnership with in-situ measurements from the THEMIS probes, and contribute towards resolving the causal sequence of energy release in the substorm cycle.

  4. Automated Detection and Tracking of Equatorial Plasma Depletions Using Ground-Based Optical Imagers

    NASA Astrophysics Data System (ADS)

    Pedersen, T.; Carrano, C.; Griffin, J.

    2004-12-01

    Optical imaging is one of the few means available for determining space weather parameters simultaneously over large areas, but tropospheric cloud cover presents a significant barrier to operational use of data from ground-based optical instruments. Distributed sensors experiencing different tropospheric conditions but with overlapping fields of view in the upper atmosphere are one possible solution to the cloud cover difficulty, while intelligent processing of imager data to discriminate between clouds and upper atmospheric features is another potential means of providing reliable data output from only a single instrument. We evaluate and discuss a variety of processing algorithms developed or adapted for the purpose of detecting and tracking equatorial plasma depletions in all-sky imager data under realistic conditions including significant cloud cover. Our most successful technique thus far relies on discrimination between depletions and other image features based on their signatures in velocity and correlation space rather than physical coordinates. In addition to allowing identification and tracking of the depletions, accurate knowledge of the velocity allows multiple frames of image data to be processed coherently in the reference frame moving with the depletions. This processing can virtually eliminate cloud effects up to 50 percent cloud cover. With externally provided velocity information (such as from a spaced-antenna scintillation system, for example) or an improved velocity algorithm, useful data can be obtained at even greater cloud cover fractions. A similar motion-based technique can also be applied to the background star field, allowing stars to be easily distinguished from pixel noise and hot pixels for rapid automatic identification of image regions affected by clouds without the need to identify, locate, or track any specific stars.

  5. Characterization of Oribtal Debris via Hyper-Velocity Ground-Based Tests

    NASA Technical Reports Server (NTRS)

    Cowardin, H.

    2015-01-01

    Existing DoD and NASA satellite breakup models are based on a key laboratory-based test, Satellite Orbital debris Characterization Impact Test (SOCIT), which has supported many applications and matched on-orbit events involving older satellite designs reasonably well over the years. In order to update and improve the break-up models and the NASA Size Estimation Model (SEM) for events involving more modern satellite designs, the NASA Orbital Debris Program Office has worked in collaboration with the University of Florida to replicate a hypervelocity impact using a satellite built with modern-day spacecraft materials and construction techniques. The spacecraft, called DebriSat, was intended to be a representative of modern LEO satellites and all major designs decisions were reviewed and approved by subject matter experts at Aerospace Corporation. DebriSat is composed of 7 major subsystems including attitude determination and control system (ADCS), command and data handling (C&DH), electrical power system (EPS), payload, propulsion, telemetry tracking and command (TT&C), and thermal management. To reduce cost, most components are emulated based on existing design of flight hardware and fabricated with the same materials. All fragments down to 2 mm is size will be characterized via material, size, shape, bulk density, and the associated data will be stored in a database for multiple users to access. Laboratory radar and optical measurements will be performed on a subset of fragments to provide a better understanding of the data products from orbital debris acquired from ground-based radars and telescopes. The resulting data analysis from DebriSat will be used to update break-up models and develop the first optical SEM in conjunction with updates into the current NASA SEM. The characterization of the fragmentation will be discussed in the subsequent presentation.

  6. Ground based radar measurements in a marine environment for glacier calving front studies.

    NASA Astrophysics Data System (ADS)

    Rolstad Denby, C.; Gundersen, R.

    2012-04-01

    A ground-based radar has been used successfully for monitoring velocities and calving events at Kronebreen, Svalbard, for four test seasons in 2007,2008, 2009 and 2010. The radar is placed ~4 km from the glacier front and it transmits the signal across Kongsfjorden. It transmits at 5.75 GHz and measures at high temporal rate (2 Hz). The antenna lobe covers a width of~700m of the calving front, and a range of 300 m. The latter includes the calving front and 250m up-glacier. We find that the glacier surface provides natural permanent scatterers, so spatially continuous movements at the front and at locations further up-glacier can be tracked. High frequent noise is present in the velocity data. We used daily terrestrial optical photogrammetry and continuous visual observation to validate the identification of calving events in a 116 hour record of amplitude of return signal data measured from 26 to 30 August 2008. Calving events were detected applying an automated change-detection technique to the radar dataset. This technique allowed us to detect 92% of the events that were observed during the same time. We also observe that the marine environment affects the radar signal in several ways. Destructive interference due to multipath scattering covers an enlarged area in the amplitude data set due to the tidal cycles. The transmitted and received radar signal is disturbed due to variations in the refraction index over the fjord. High frequent noise as observed on the velocity measurements may be due to ocean water waves in the fjord. The observed noise may be affected by the choice of antenna polarization. Plans for an improved version of the radar system designed for calving front monitoring and 2D mapping of glacier velocities will also be presented.

  7. Constraints on Mercury's Na Exosphere: Combined MESSENGER and Ground-Based Data

    NASA Technical Reports Server (NTRS)

    Mouawad, Nelly; Burger, Matthew H.; Killen, Rosemary M.; Potter, Andrew E.; McClintock, William E.; Vervack, Ronald J., Jr.; Bradley, E. Todd; Benna, Mehdi; Naidu, Shantanu

    2010-01-01

    We have used observations of sodium emission obtained with the McMath-Pierce solar telescope and MESSENGER's Mercury Atmospheric and Surface Composition Spectrometer (MASCS) to constrain models of Mercury's sodium exosphere, The distribution of sodium in Mercury's exosphere during the period January 12-15. 2008. was mapped using the McMath-Pierce solar telescope with the 5" X 5" image slicer to observe the D-line emission. On January 14, 2008, the Ultraviolet and Visible Spectrometer (UVVS) channel on MASCS sampled the sodium in Mercury's anti-sunward tail region. We find that the bound exosphere has an equivalent temperature of 900-1200 K, and that this temperature can be achieved if the sodium is ejected either by photon-stimulated desorption (PSD) with a 1200 K Maxwellian velocity distribution, or by thermal accommodation of a hotter source. We were not able to discriminate between the two assumed velocity distributions of the ejected particles for the PSD. but the velocity distributions require different values of the thermal accommodation coefficient and result in different upper limits on impact vaporization, We were able to place a strong constraint on the impact vaporization rate that results in the release of neutral Na atoms with an upper limit of 2.1 x 10(exp 6) sq cm/s, The variability of the week-long ground-based observations can be explained by variations in the sources, including both PSD and ion-enhanced PSD, as well as possible temporal enhancements in meteoroid vaporization. Knowledge of both dayside and anti-sunward tail morphologies and radiances are necessary to correctly deduce the exospheric source rates, processes, velocity distribution, and surface interaction.

  8. Validation of CALIPSO level-2 products using a ground based lidar in Thessaloniki, Greece

    NASA Astrophysics Data System (ADS)

    Giannakaki, Elina; Vraimaki, Eleni; Balis, Dimitris

    2011-11-01

    We present initial aerosol validation results of the space-borne lidar CALIOP -onboard the CALIPSO satellite - Level 2 extinction coefficient profiles, using coincident observations performed with a ground-based lidar in Thessaloniki, Greece (40.5° N, 22.9° E, 50m above sea level). A ground-based backscatter/Raman lidar system is operating since 2000 at the Laboratory of Atmospheric Physics (LAP) in the framework of the European Aerosol Research LIdar NETwork (EARLINET), the first lidar network for tropospheric aerosol studies on a continental scale. Since July 2006, a total of 150 coincidental aerosol ground-based lidar measurements were performed over Thessaloniki during CALIPSO overpasses. The ground-based measurements were performed each time CALIPSO overpasses the station location within a maximum distance of 100 km. The duration of the ground-based lidar measurements was approximately two hours, centred on the satellite overpass time. The analysis was performed for 4 different horizontal resolutions of 5, 25, 45 and 105 km. For our analysis we have used Atmospheric Volume Description (AVD) array to screen out everything that is not an aerosol. Also, the cloud-aerosol discrimination (CAD) score, which provides a numerical confidence level for the classification of layers by the CALIOP cloud-aerosol discrimination algorithm was set between -80 and -100. CALIPSO extinction QC flags, which summarize the final state of the extinction retrieval, was also used. In our analysis we have used those measurements where the lidar ratio is unchanged (extinction QC = 0) during the extinction retrieval or it the retrieval is constrained (extinction QC = 1). The comparison was performed both for extinction and backscater coefficient profiles. For clear sky conditions, the comparison shows good performances of the CALIPSO on-board lidar.

  9. The Irregular Shape of (21) Lutetia as Determined from Ground-based Observations

    NASA Astrophysics Data System (ADS)

    Conrad, A.; Carry, B.; Merline, W. J.; Drummond, J. D.; Chapman, C. R.; Tamblyn, P. M.; Christou, J. C.; Dumas, C.; Weaver, H. A.; Rosetta OSIRIS Instument Team

    2010-12-01

    We report the results of our campaign to improve our understanding of the physical characteristics of asteroid (21) Lutetia ahead of the Rosetta flyby in 2010 July. This included measurements of shape, size, pole, density, and a search for satellites. We utilized primarily adaptive optics (AO) on large ground-based telescopes (Keck, Gemini, and VLT). We coordinated these efforts with HST observations (Weaver et al. 2010, A&A 518, A4), made in support of Rosetta’s ALICE UV spectrometer. Preliminary results were supplied to Rosetta mission teams in fall of 2009 to assist in planning for the mission. Observations and analyses were complete and submitted for publication before the flyby (Drummond et al. 2010, A&A, in press; Carry et al. 2010, A&A, in press). Using more than 300 AO images of Lutetia, which subtended only slightly more than two resolution-elements (0.10”) for these large telescopes, we were able to derive accurate size and shape information, as well as a pole and spin period. We modeled the size and shape using both a triaxial-ellipsoid model and a 3D radius-vector model. The radius-vector model used our new technique of multi-dataset inversion, called KOALA (for Knitted Occultation, Adaptive optics, and Lightcurve Analysis), in which we utilized not only our AO imaging, but also 50 lightcurves spanning 48 years. We combined the best aspects of each model to produce our best-estimate 3D shape model, a hybrid having ellipsoid-equivalent dimensions of 124 x 101 x 93 km (± 5 x 4 x 13 km) and effective diameter 105 ± 7 km. We found the spin axis of Lutetia to lie within 5 deg of [long, lat (52,-6)] or [RA DEC (52,+12)] and determined an improved sidereal period of 8.168270 ± 0.000001 h. We predicted the geometry of Lutetia during the flyby and showed that the southern hemisphere would be in seasonal shadow at that time. The model suggested the presence of several concavities and irregularities that may be associated with large impacts. The model

  10. New measurements of Venus winds with ground-based Doppler velocimetry at CFHT

    NASA Astrophysics Data System (ADS)

    Machado, P.; Widemann, T.; Luz, D.; Peralta, J.; Berry, D. L.

    2012-04-01

    measurements made with the VMC camera onboard the Venus Express. We will present first results from this work, comparing with previous results by the CFHT/ESPaDOnS and VLT-UVES spectrographs (Machado et al., 2012), with Galileo fly-by measurements and with VEx nominal mission observations (Peralta et al., 2007, Luz et al., 2011). Acknowledgements: The authors acknowledge support from FCT through projects PTDC/CTE-AST/110702/2009 and PEst-OE/FIS/UI2751/2011. PM and TW also acknowledge support from the Observatoire de Paris. Lellouch, E., and Witasse, O., A coordinated campaign of Venus ground-based observations and Venus Express measurements, Planetary and Space Science 56 (2008) 1317-1319. Luz, D., et al., Venus's polar vortex reveals precessing circulation, Science 332 (2011) 577-580. Machado, P., Luz, D. Widemann, T., Lellouch, E., Witasse, O, Characterizing the atmospheric dynamics of Venus from ground-based Doppler velocimetry, Icarus, submitted. Peralta J., R. Hueso, A. Sánchez-Lavega, A reanalysis of Venus winds at two cloud levels from Galileo SSI images, Icarus 190 (2007) 469-477. Widemann, T., Lellouch, E., Donati, J.-F., 2008, Venus Doppler winds at Cloud Tops Observed with ESPaDOnS at CFHT, Planetary and Space Science, 56, 1320-1334.

  11. Comparing distinct ground-based lightning location networks covering the Netherlands

    NASA Astrophysics Data System (ADS)

    de Vos, Lotte; Leijnse, Hidde; Schmeits, Maurice; Beekhuis, Hans; Poelman, Dieter; Evers, Läslo; Smets, Pieter

    2015-04-01

    Lightning can be detected using a ground-based sensor network. The Royal Netherlands Meteorological Institute (KNMI) monitors lightning activity in the Netherlands with the so-called FLITS-system; a network combining SAFIR-type sensors. This makes use of Very High Frequency (VHF) as well as Low Frequency (LF) sensors. KNMI has recently decided to replace FLITS by data from a sub-continental network operated by Météorage which makes use of LF sensors only (KNMI Lightning Detection Network, or KLDN). KLDN is compared to the FLITS system, as well as Met Office's long-range Arrival Time Difference (ATDnet), which measures Very Low Frequency (VLF). Special focus lies on the ability to detect Cloud to Ground (CG) and Cloud to Cloud (CC) lightning in the Netherlands. Relative detection efficiency of individual flashes and lightning activity in a more general sense are calculated over a period of almost 5 years. Additionally, the detection efficiency of each system is compared to a ground-truth that is constructed from flashes that are detected by both of the other datasets. Finally, infrasound data is used as a fourth lightning data source for several case studies. Relative performance is found to vary strongly with location and time. As expected, it is found that FLITS detects significantly more CC lightning (because of the strong aptitude of VHF antennas to detect CC), though KLDN and ATDnet detect more CG lightning. We analyze statistics computed over the entire 5-year period, where we look at CG as well as total lightning (CC and CG combined). Statistics that are considered are the Probability of Detection (POD) and the so-called Lightning Activity Detection (LAD). POD is defined as the percentage of reference flashes the system detects compared to the total detections in the reference. LAD is defined as the fraction of system recordings of one or more flashes in predefined area boxes over a certain time period given the fact that the reference detects at least one

  12. The Aries auroral modelling campaign - Characterization and modelling of an evening auroral arc observed from a rocket and a ground-based line of meridian scanners

    NASA Technical Reports Server (NTRS)

    Jones, A. V.; Gattinger, R. L.; Creutzberg, F.; Harris, F. R.; Mcnamara, A. G.; Yau, A. W.; Llewellyn, E. J.; Lummerzheim, D.; Rees, M. H.; Mcdade, I. C.

    1991-01-01

    A summary of the Aries experiments and results is presented with specific attention given to the tomographic analysis developed from ground-based photometric data. The instrumentation includes particle detectors, rocket photometers, plasma probes, and 1-deg meridian scanning photometers, and an all-sky TV system. The geophysical conditions during the observations are described including the auroral features and wavelengths, rocket trajectories, and the effectiveness of particle measurements. The tomographic inversion is explained with examples of rocket-photometer height data and contrasted with ground-based photometric data. The modeling techniques used to derive height profiles are described and indirectly compared to measured auroral intensities and intensity ratios. An enhancement of atomic oxygen is inferred from discrepancies with previous studies which confirm the difference between observed intensity ratios and modeled results.

  13. Coordinated use of ground-based auroral and high-precision LEO magnetic and electric field measurements to investigate auroral electrodynamics

    NASA Astrophysics Data System (ADS)

    Donovan, E.

    2008-12-01

    There are now dozens of sensitive All-Sky Imagers (ASIs) deployed in networks spanning latitudes from the subauroral zone into the polar cap and many hours of magnetic local time. These new networks are collecting data with unprecedented spatial coverage and temporal resolution and in numerous scientifically interesting wavelength ranges. As well, direct satellite overflights of ground-based images that were once rare occurrences are becoming increasingly commonplace. This talk will focus on the scientific opportunities afforded by the integrated use of ground-based auroral images and magnetic and electric field data from existing and planned LEO missions including CHAMP, Oersted, and Swarm. These opportunities include exploring the relationship between field-aligned current and Poynting flux and different types of aurora, as well as reducing spatio-temporal ambiguity in the in situ measurements.

  14. In Vitro Antimicrobial Activity of a Siderophore Cephalosporin, S-649266, against Enterobacteriaceae Clinical Isolates, Including Carbapenem-Resistant Strains.

    PubMed

    Kohira, Naoki; West, Joshua; Ito, Akinobu; Ito-Horiyama, Tsukasa; Nakamura, Rio; Sato, Takafumi; Rittenhouse, Stephen; Tsuji, Masakatsu; Yamano, Yoshinori

    2015-11-16

    S-649266 is a novel siderophore cephalosporin antibiotic with a catechol moiety on the 3-position side chain. Two sets of clinical isolate collections were used to evaluate the antimicrobial activity of S-649266 against Enterobacteriaceae. These sets included 617 global isolates collected between 2009 and 2011 and 233 β-lactamase-identified isolates, including 47 KPC-, 49 NDM-, 12 VIM-, and 8 IMP-producers. The MIC90 values of S-649266 against the first set of Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Citrobacter freundii, Enterobacter aerogenes, and Enterobacter cloacae isolates were all ≤1 μg/ml, and there were only 8 isolates (1.3%) among these 617 clinical isolates with MIC values of ≥8 μg/ml. In the second set, the MIC values of S-649266 were ≤4 μg/ml against 109 strains among 116 KPC-producing and class B (metallo) carbapenemase-producing strains. In addition, S-649266 showed MIC values of ≤2 μg/ml against each of the 13 strains that produced other types of carbapenemases such as SME, NMC, and OXA-48. The mechanisms of the decreased susceptibility of 7 class B carbapenemase-producing strains with MIC values of ≥16 μg/ml are uncertain. This is the first report to demonstrate that S-649266, a novel siderophore cephalosporin, has significant antimicrobial activity against Enterobacteriaceae, including strains that produce carbapenemases such as KPC and NDM-1.

  15. High-resolution, high-sensitivity, ground-based solar spectropolarimetry with a new fast imaging polarimeter. I. Prototype characterization

    NASA Astrophysics Data System (ADS)

    Iglesias, F. A.; Feller, A.; Nagaraju, K.; Solanki, S. K.

    2016-05-01

    Context. Remote sensing of weak and small-scale solar magnetic fields is of utmost relevance when attempting to respond to a number of important open questions in solar physics. This requires the acquisition of spectropolarimetric data with high spatial resolution (~10-1 arcsec) and low noise (10-3 to 10-5 of the continuum intensity). The main limitations to obtain these measurements from the ground, are the degradation of the image resolution produced by atmospheric seeing and the seeing-induced crosstalk (SIC). Aims: We introduce the prototype of the Fast Solar Polarimeter (FSP), a new ground-based, high-cadence polarimeter that tackles the above-mentioned limitations by producing data that are optimally suited for the application of post-facto image restoration, and by operating at a modulation frequency of 100 Hz to reduce SIC. Methods: We describe the instrument in depth, including the fast pnCCD camera employed, the achromatic modulator package, the main calibration steps, the effects of the modulation frequency on the levels of seeing-induced spurious signals, and the effect of the camera properties on the image restoration quality. Results: The pnCCD camera reaches 400 fps while keeping a high duty cycle (98.6%) and very low noise (4.94 e- rms). The modulator is optimized to have high (>80%) total polarimetric efficiency in the visible spectral range. This allows FSP to acquire 100 photon-noise-limited, full-Stokes measurements per second. We found that the seeing induced signals that are present in narrow-band, non-modulated, quiet-sun measurements are (a) lower than the noise (7 × 10-5) after integrating 7.66 min, (b) lower than the noise (2.3 × 10-4) after integrating 1.16 min and (c) slightly above the noise (4 × 10-3) after restoring case (b) by means of a multi-object multi-frame blind deconvolution. In addition, we demonstrate that by using only narrow-band images (with low S/N of 13.9) of an active region, we can obtain one complete set of high

  16. Activity of eravacycline against Enterobacteriaceae and Acinetobacter baumannii, including multidrug-resistant isolates, from New York City.

    PubMed

    Abdallah, Marie; Olafisoye, Olawole; Cortes, Christopher; Urban, Carl; Landman, David; Quale, John

    2015-03-01

    Eravacycline demonstrated in vitro activity against a contemporary collection of more than 4,000 Gram-negative pathogens from New York City hospitals, with MIC50/MIC90 values, respectively, for Escherichia coli of 0.12/0.5 μg/ml, Klebsiella pneumoniae of 0.25/1 μg/ml, Enterobacter aerogenes of 0.25/1 μg/ml, Enterobacter cloacae 0.5/1 μg/ml, and Acinetobacter baumannii of 0.5/1 μg/ml. Activity was retained against multidrug-resistant isolates, including those expressing KPC and OXA carbapenemases. For A. baumannii, eravacycline MICs correlated with increased expression of the adeB gene. PMID:25534744

  17. Comparison of NLDAS Weather Forcing Data with Ground-based Measurements in Irrigated Areas of Utah

    NASA Astrophysics Data System (ADS)

    Neale, C. M.; Geli, H. M.; Lewis, C. S.; Verdin, J. P.; Senay, G. B.

    2012-12-01

    This analysis is being conducted in the context of standardizing and providing guidelines for the production of evapotranspiration (ET) and crop water use maps in the Western United States, a project funded by the USGS. Spatial ET maps can be obtained using remote sensing-based methods at field/local scales. There are presently different remote sensing methods in the literature that provide reasonable levels of accuracy at these scales. Most of these methods use weather data from ground-based weather stations in the area being modeled with the assumption of being reasonably representative of the local conditions. Ground-based stations are generally sparse in nature for various reasons. However, at regional/continental scales this assumption will not be applicable and requires the use of other approaches to account for the variability of the near surface weather conditions. The North American Land Data Assimilation System (NLDAS) which provides gridded weather forcing data can potentially provide such information. These NLDAS data are available at 1/8th of a degree grid (~ 14 km × 14 km) a relatively coarse resolution considering the requirement of estimating ET at field scales. In order to use the NLDAS weather forcing data in remote sensing of ET at field to regional scales with increased confidence, it is important to compare it with ground-based observations under different surface conditions. Such comparison will help to identify the associated uncertainties and biases. It can also help to quantify the uncertainties in the remote sensing-based model estimates of ET. This study presents a preliminary result the comparison between ground-based weather data to the NLDAS gridded products in irrigated areas. Ground-based data from about 24 stations in and around the state of Utah, maintained by the National Weather Service and Utah State University, are used in the analysis. The comparison considered both hourly and daily data. These stations were operated over

  18. Ionospheric and magnetospheric effects of solar flares monitored by ground-based riometer and magnetometers

    NASA Astrophysics Data System (ADS)

    Ronan Coelho Stekel, Tardelli; Schuch, Nelson Jorge; Echer, Ezequiel; Guarnieri, Fernando; Makita, Kazuo; Espindola Antunes, Cassio; Moro, Juliano; Machado Paulo, Claudio

    The solar flare incidence follows a behavior similar to the solar cycle activity, which results in periodic disturbances on the Earth's ionosphere and magnetosphere. The correlation of this phenomenon can provide important information about the magnetosphere, the Sun/Earth interaction, as well as events occurring in the ionosphere which can, for instance, generate disturbances in telecommunications, small satellites or even in the space weather. Riometer and magnetometers data analysis can provide useful way for measuring and understanding the effects of solar flare radiation in the ionosphere and magnetosphere. The Solar Flare effect (SFE) is associated with the sudden change of ionospheric currents caused by the extra ionization produced by soft X-ray (0.1 to 9.0 nm) and EUV (9.0 to 100.0 nm) radiation from the solar flare. The objective of this work is to present the correlation of the ionospheric and magnetospheric (H, D, Z) sudden disturbances due to high-intensity solar flares (M and X class), that can emit up to 1032 ergs of energy. For this purpose, analysis were performed for the riometer and magnetometers dedicated to study the Solar-Earth interactions at the Southern Space Observatory (SSO/CRS/INPE -MCT), (29.4° S, 53.8° W, 480m a.s.l), São Martinho da a Serra, RS, Brazil. To identify and investigate the sudden radiation increase caused by the solar flare, the X-ray data (0.1 to 0.8 nm) from GOES Satellites and the EUV data (26.0 to 34.0 nm and 0.1 to 50.0 nm) from the Solar EUV Monitor (SEM) on the SOHO spacecraft are correlated. With the analysis of these ground-based instruments and spacecrafts data, the correlation of the solar activity and the magnetospheric and ionospheric disturbances were performed, as for the Sudden Ionospheric Disturbance (SID) and Magnetic Crochet about 60% D-component variation during a large solar flare was observed.

  19. Insights into Io’s volcanoes by combining ground-based and spacecraft data

    NASA Astrophysics Data System (ADS)

    Rathbun, Julie A.; Spencer, John R.; Howell, Robert; Lopes, Rosaly

    2015-11-01

    combined to yield greater information into the nature of Io’s volcanism and we will discuss how ground-based observations during future missions can be optimized for the greatest scientific output.

  20. Ground-based and satellite remote sensing of paroxysmal eruptions at Etna volcano, 2011-2012

    NASA Astrophysics Data System (ADS)

    Bonny, Estelle

    Mt Etna's activity has increased during the last decade with a tendency towards more explosive eruptions that produce paroxysmal lava fountains. From January 2011 to April 2012, 25 lava fountaining episodes took place at Etna's New South-East Crater (NSEC). Improved understanding of the mechanism driving these explosive basaltic eruptions is needed to reduce volcanic hazards. This type of activity produces high sulfur dioxide (SO2) emissions, associated with lava flows and ash fall-out, but to date the SO2 emissions associated with Etna's lava fountains have been poorly constrained. The Ultraviolet (UV) Ozone Monitoring Instrument (OMI) on NASA's Aura satellite and the Atmospheric Infrared Sounder (AIRS) on Aqua were used to measure the SO2 loadings. Ground-based data from the Observatoire de Physique du Globe de Clermont-Ferrand (OPGC) L-band Doppler radar, VOLDORAD 2B, used in collaboration with the Italian National Institute of Geophysics and Volcanology in Catania (INGV-CT), also detected the associated ash plumes, giving precise timing and duration for the lava fountains. This study resulted in the first detailed analysis of the OMI and AIRS SO2 data for Etna's lava fountains during the 2011-2012 eruptive cycle. The HYSPLIT trajectory model is used to constrain the altitude of the observed SO2 clouds, and results show that the SO2 emission usually coincided with the lava fountain peak intensity as detected by VOLDORAD. The UV OMI and IR AIRS SO2 retrievals permit quantification of the SO2 loss rate in the volcanic SO2 clouds, many of which were tracked for several days after emission. A first attempt to quantitatively validate AIRS SO2 retrievals with OMI data revealed a good correlation for high altitude SO2 clouds. Using estimates of the emitted SO2 at the time each paroxysm, we observe a correlation with the inter-paroxysm repose time. We therefore suggest that our data set supports the collapsing foam (CF) model [1] as driving mechanism for the paroxysmal

  1. Ground-based radiometric calibration of the Landsat 8 Operational Land Imager (OLI) using in situ techniques

    NASA Astrophysics Data System (ADS)

    Czapla-Myers, J.

    2013-12-01

    Landsat 8 was successfully launched from Vandenberg Air Force Base in California on 11 February 2013, and was placed into the orbit previously occupied by Landsat 5. Landsat 8 is the latest platform in the 40-year history of the Landsat series of satellites, and it contains two instruments that operate in the solar-reflective and the thermal infrared regimes. The Operational Land Imager (OLI) is a pushbroom sensor that contains eight multispectral bands ranging from 400-2300 nm, and one panchromatic band. The spatial resolution of the multispectral bands is 30 m, which is similar to previous Landsat sensors, and the panchromatic band has a 15-m spatial resolution, which is also similar to previous Landsat sensors. The 12-bit radiometric resolution of OLI improves upon the 8-bit resolution of the Enhanced Thematic Mapper Plus (ETM+) onboard Landsat 7. An important requirement for the Landsat program is the long-term radiometric continuity of its sensors. Ground-based vicarious techniques have been used for over 20 years to determine the absolute radiometric calibration of sensors that encompass a wide variety of spectral and spatial characteristics. This work presents the early radiometric calibration results of Landsat 8 OLI that were obtained using the traditional reflectance-based approach. University of Arizona personnel used five sites in Arizona, California, and Nevada to collect ground-based data. In addition, a unique set of in situ data were collected in March 2013, when Landsat 7 and Landsat 8 were observing the same site within minutes of each other. The tandem overfly schedule occurred while Landsat 8 was shifting to the WRS-2 orbital grid, and lasted only a few days. The ground-based data also include results obtained using the University of Arizona's Radiometric Calibration Test Site (RadCaTS), which is an automated suite of instruments located at Railroad Valley, Nevada. The results presented in this work include a comparison to the L1T at

  2. Evaluation of Tropical Cirrus Cloud Properties Derived from ECMWF Model Output and Ground Based Measurements over Nauru Island

    SciTech Connect

    Comstock, Jennifer M.; Jakob, Christian

    2004-05-26

    Cirrus clouds play an important role both radiatively and dynamically in the tropics. Understanding the mechanisms responsible for the formation and persistence of tropical cirrus is an important step in accurately predicting cirrus in forecast models. In this study, we compare ground-based measurements of cloud properties with those predicted by the ECMWF model at a location in the tropical western Pacific. Our comparisons of cloud height and optical depth over an 8 month time period indicate that the model and measurements agree relatively well. The ECMWF model predicts cirrus anvils associated with deep convection during convectively active periods, and also isolated cirrus events that are influenced by large-scale vertical ascent. We also show through examination of an upper tropospheric cirrus case that the model produces tropospheric waves that appear to influence the morphology and maintenance of the cirrus layer.

  3. Summary of flight tests of an airborne lighting locator system and comparison with ground-based measurements of precipitation and turbulence

    NASA Technical Reports Server (NTRS)

    Fisher, B. D.; Crabill, N. L.

    1981-01-01

    Data from an airborne lightning locator system and data relating to storm intensity obtained by ground-based Doppler radars and the S-band research radar are presented. When comparing lightning locations from the airborne lightning locator system with ground-based Doppler radar measurements of reflectivity and spectrum width, the lightning locations tended to be further from the aircraft position than the Doppler radar contours, but at the same relative bearing from the aircraft as the Doppler contours. The results also show that convective storms generate little or no lightning for a significant part of their life cycle, but can produce at least moderate turbulence. Therefore, it is concluded that a lack of lightning activity cannot be accepted as an inference of a corresponding lack of other hazards to the flight of aircraft through convective storms.

  4. Update of the ISTP Solar Maximum Mission: ISTP Project Scientist for Theory and Ground-Based Observations

    NASA Technical Reports Server (NTRS)

    Curtis, Steve

    1999-01-01

    Building upon the numerous successes of the pre-solar maximum International Solar Terrestrial Physics (ISTP) mission, the ISTP Solar Maximum Mission is expected to produce new insights into global flow of energy, momentum, and mass, from the Sun, through the heliosphere, into the magnetosphere and to their final deposition in the terrestrial upper atmosphere/ionosphere system. Of particular interest is the determination of the geo-effectiveness of solar events, principally Coronal Mass Ejections (CMEs). Given the expected increased frequency and strength of CMEs during the Solar Maximum period, a major advance in our understanding of nature of the coupling of CMEs to the magnetosphere-ionosphere-atmosphere system is expected. The roles during this time of the various ISTP assets will be discussed. These assets will include the SOHO, Wind, Polar, and Geotail spacecraft, the ground-based observing networks and the theory tools.

  5. THE 1998 NOVEMBER 14 OCCULTATION OF GSC 0622-00345 BY SATURN. I. TECHNIQUES FOR GROUND-BASED STELLAR OCCULTATIONS

    SciTech Connect

    Harrington, Joseph; French, Richard G. E-mail: rfrench@wellesley.ed

    2010-06-10

    On 1998 November 14, Saturn and its rings occulted the star GSC 0622-00345. We observed atmospheric immersion with NSFCAM at the National Aeronautics and Space Administration's Infrared Telescope Facility on Mauna Kea, Hawaii. Immersion occurred at 55.{sup 0}5 S planetocentric latitude. A 2.3 {mu}m, CH{sub 4}-band filter suppressed reflected sunlight. Atmospheric emersion and ring data were not successfully obtained. We describe our observation, light curve production, and timing techniques, including improvements in aperture positioning, removal of telluric scintillation effects, and timing. Many of these techniques are known within the occultation community, but have not been described in the reviewed literature. We present a light curve whose signal-to-noise ratio per scale height is 267, among the best ground-based signals yet achieved, despite a disadvantage of up to 8 mag in the stellar flux compared to prior work.

  6. Atmospheric boundary layer observation by ground-based lidar at KMITL, Thailand 13 deg N, 100 deg E

    NASA Astrophysics Data System (ADS)

    Lerkvaranyu, Somkiat; Dejhan, Kobchai; Cheevasuvit, Fusak; Itabe, Toshikasu; Mizutani, Kohei; Aoki, Tetsuo; Yasui, Motoaki

    2001-02-01

    Tropospheric aerosols effects on climate in directly through various cloud formation, the lidar has been used to study the composition of many particles mixing in the atmosphere including to study the aerosol and cloud. Currently, it has many types of lidar systems depending on the purpose of measurements. In this report, the ground-based lidar system was established at King Mongkut's Institute of Technology Ladkrabang (KMITL), THAILAND to study and measure the aerosol in boundary layer and cirrus clouds in the tropopause region. The aerosol measurement is in the form of scattering ratio whereas the signal depolarization has been applied to identify layers of cirrus clouds. The lidar system consists of laser source (Nd:YAG) with second harmonic wavelength, 28 cm Schmidt-Cassegrain telescope, photomultiplier tube (PMT) and data acquisition system.

  7. Integrated Analysis of Asian Dust Events from CALIPSO Space Lidar Data in Conjunction with Passive Remote Sensing and Ground-Based Observations

    NASA Astrophysics Data System (ADS)

    Choi, H.; Sokolik, I. N.; Winker, D. M.; Kurosaki, Y.

    2008-05-01

    The vast arid regions of East Asia are active dust sources. Each spring, large amounts of mineral dust are emitted into the atmosphere, affecting the regional air quality, environment and climate. This study presents analyses of Asian dust events by integrating CALIPSO lidar data with A-Train satellite multi-sensor observations (Ozone Monitoring Instrument, OMI, and Moderate-Resolution Imaging Spectroradiometer, MODIS) as well as ground-based observations. We use data from WMO meteorological stations located in China, Mongolia, Korea and Japan that report different present weather types related to dust events. Also, lidar data from Asian network sites were included in the analysis. The focus is on dust events that occurred during the spring seasons of 2006- 2008. The capability of CALIPSO to detect dust was investigated by analyzing the CALIPSO features against independent observations for selected CALPSO overpasses on a case-by-case basis. The changes in the linear depolarization ratio were analyzed in conjunction with T-matrix optical modeling to constrain the particle nonsphericity and size distribution. The dust properties and vertical distribution in different dust sources (the Taklamakan vs. Gobi) were analyzed. The evolution of dust properties during the mid-range transport was also investigated from combined CALIPSO and lidar data.

  8. Ground-Based Testing of TiB2 and Al2O3/TiB2 Response to Space Environment

    NASA Technical Reports Server (NTRS)

    Jefferies, Sharon A.; Logan, Kathryn V.

    2007-01-01

    Two materials, titanium diboride and an alumina/titanium diboride composite, exhibit characteristics favorable for use in multiple space applications. These characteristics include low mass (4.52 gm/cc), high strain rate impact resistance, high temperature use (3000oC M.P.), thermal and electrical conductivity, thermal shock resistance, and high visible-range reflectivity. Additionally, the presence of boron in these materials gives them the potential to shield against neutron radiation as well as charged radiation. These materials are flying on MISSE 6 to assess material changes resulting from exposure to the space environment. This study provides a preliminary, ground-based examination of these materials' interactions with individual components of the space environment, in particular atomic oxygen (AO) and neutron radiation, in order to better predict and understand post-flight results. Individual specimens are exposed to ground state AO and surface oxidation is measured. Equivalent exposures of up to 13 months show no rapid oxidation, however evidence indicates some surface oxidation occurring. Other samples are placed near a polyethylene moderated, one Ci Am/Be neutron source to determine their shielding capability. Comparisons between exposed and shielded indium foil, which is activated by transmitted neutrons, measure each material's ability to shield neutrons. Preliminary results indicate a significant shielding benefit provided by both materials.

  9. Atomic oxygen interaction with spacecraft materials: Relationship between orbital and ground-based testing for materials certification

    SciTech Connect

    Cross, J.B. ); Koontz, S.L. . Lyndon B. Johnson Space Center); Lan, E.H. )

    1991-01-01

    The effects of atomic oxygen on boron nitride, silicon nitride, solar cell interconnects used on the Intelsat 6 satellite, organic polymers, and MoS{sub 2} and WS{sub 2} dry lubricant have been studied in low Earth orbit (LEO) flight experiments and in our ground-based simulation facility at Los Alamos National Laboratory. Both the in-flight and ground-based experiments employed in situ electrical resistance measurements to detect penetration of atomic oxygen through materials and ESCA analysis to measure chemical composition changes. In the presence of atomic oxygen, silver oxidizes to form silver oxide, which has a much higher electrical resistance than pure silver. Permeation of atomic oxygen through BN overcoated on thin silver was observed. No permeation of atomic oxygen through Si{sub 3}N{sub 4} was observed. Test results on the Intelsat 6 satellite interconnects used on its photovoltaic array indicate that more than 60--80% of the original thickness of silver should remain after completion of the proposed Space Shuttle rescue/reboost mission. Gas phase reaction products produced by the interaction of high kinetic energy atomic oxygen (AO) with Kapton were found to be H{sub 2}, H{sub 2}O, CO, and CO{sub 2} with NO being a possible secondary product. Hydrogen abstraction at high AO kinetic energy is postulated to be the key reaction controlling the erosion rate of Kapton. An Arrhenius-like expression having an activation barrier of 0.4 eV can be fit to the data, which suggests that the rate limiting step in the AO/Kapton reaction mechanism can be overcome by translational energy. Oxidation of MoS{sub 2} and WS{sub 2} dry lubricants in both ground-based and orbital exposures indicated the formation of MoO{sub 3} and WO{sub 3} respectively. A protective oxide layer is formed {approx}30 monolayers thick which has a high initial friction coefficient until the layer is worn off.

  10. The NLP toxin family in Phytophthora sojae includes rapidly evolving groups that lack necrosis-inducing activity.

    PubMed

    Dong, Suomeng; Kong, Guanghui; Qutob, Dinah; Yu, Xiaoli; Tang, Junli; Kang, Jixiong; Dai, Tingting; Wang, Hai; Gijzen, Mark; Wang, Yuanchao

    2012-07-01

    Necrosis- and ethylene-inducing-like proteins (NLP) are widely distributed in eukaryotic and prokaryotic plant pathogens and are considered to be important virulence factors. We identified, in total, 70 potential Phytophthora sojae NLP genes but 37 were designated as pseudogenes. Sequence alignment of the remaining 33 NLP delineated six groups. Three of these groups include proteins with an intact heptapeptide (Gly-His-Arg-His-Asp-Trp-Glu) motif, which is important for necrosis-inducing activity, whereas the motif is not conserved in the other groups. In total, 19 representative NLP genes were assessed for necrosis-inducing activity by heterologous expression in Nicotiana benthamiana. Surprisingly, only eight genes triggered cell death. The expression of the NLP genes in P. sojae was examined, distinguishing 20 expressed and 13 nonexpressed NLP genes. Real-time reverse-transcriptase polymerase chain reaction results indicate that most NLP are highly expressed during cyst germination and infection stages. Amino acid substitution ratios (Ka/Ks) of 33 NLP sequences from four different P. sojae strains resulted in identification of positive selection sites in a distinct NLP group. Overall, our study indicates that expansion and pseudogenization of the P. sojae NLP family results from an ongoing birth-and-death process, and that varying patterns of expression, necrosis-inducing activity, and positive selection suggest that NLP have diversified in function.

  11. Evaluating evaporation from field crops using airborne radiometry and ground-based meteorological data

    USGS Publications Warehouse

    Jackson, R. D.; Moran, M.S.; Gay, L.W.; Raymond, L.H.

    1987-01-01

    Airborne measurements of reflected solar and emitted thermal radiation were combined with ground-based measurements of incoming solar radiation, air temperature, windspeed, and vapor pressure to calculate instantaneous evaporation (LE) rates using a form of the Penman equation. Estimates of evaporation over cotton, wheat, and alfalfa fields were obtained on 5 days during a one-year period. A Bowen ratio apparatus, employed simultaneously, provided ground-based measurements of evaporation. Comparison of the airborne and ground techniques showed good agreement, with the greatest difference being about 12% for the instantaneous values. Estimates of daily (24 h) evaporation were made from the instantaneous data. On three of the five days, the difference between the two techniques was less than 8%, with the greatest difference being 25%. The results demonstrate that airborne remote sensing techniques can be used to obtain spatially distributed values of evaporation over agricultural fields. ?? 1987 Springer-Verlag.

  12. Validation of Aura OMI by Aircraft and Ground-Based Measurements

    NASA Astrophysics Data System (ADS)

    McPeters, R. D.; Petropavlovskikh, I.; Kroon, M.

    2006-12-01

    Both aircraft-based and ground-based measurements have been used to validate ozone measurements by the OMI instrument on Aura. Three Aura Validation Experiment (AVE) flights have been conducted, in November 2004 and June 2005 with the NASA WB57, and in January/February 2005 with the NASA DC-8. On these flights, validation of OMI was primarily done using data from the CAFS (CCD Actinic Flux Spectroradiometer) instrument, which is used to measure total column ozone above the aircraft. These measurements are used to differentiate changes in stratospheric ozone from changes in total column ozone. Also, changes in ozone over high clouds measured by OMI were checked in a flight over tropical storm Arlene on a flight on June 11th. Ground-based measurements were made during the SAUNA campaign in Sodankyla, Finland, in March and April 2006. Both total column ozone and the ozone vertical distribution were validated.

  13. Method for evaluating trends in greenhouse gases from ground-based remote FTIR measurements over Europe

    NASA Astrophysics Data System (ADS)

    Gardiner, T.; Forbes, A.; Woods, P.; Demaziere, M.; Vigouroux, C.; Mahieu, E.; Demoulin, P.; Velazco, V.; Notholt, J.; Blumenstock, T.; Hase, F.; Kramer, I.; Sussman, R.; Stremme, W.; Mellqvist, J.; Strandberg, A.; Ellingsen, K.; Gauss, M.

    2007-11-01

    This paper describes the statistical analysis of annual trends in long term datasets of greenhouse gas measurements taken over ten or more years. The analysis technique employs a bootstrap resampling method to determine both the long-term and intra-annual variability of the datasets, together with the uncertainties on the trend values. The method has been applied to data from a European network of ground-based solar FTIR instruments to determine the trends in the tropospheric, stratospheric and total columns of ozone, nitrous oxide, carbon monoxide, methane, ethane and HCFC-22. The suitability of the method has been demonstrated through statistical validation of the technique, and comparison with ground-based in-situ measurements and 3-D atmospheric models.

  14. Evaluating the Accuracy of Plasmasphere Data Assimilation from Ground-Based Observations

    NASA Astrophysics Data System (ADS)

    Jorgensen, A. M.; Lichtenberger, J.; Friedel, R. H.; Clilverd, M.; Heilig, B.; Vellante, M.; Raita, T.; Rodger, C. J.; Reda, J.; Collier, A.; Holzworth, R. H.; Ober, D. M.; Boudouridis, A.; Zesta, E.; Chi, P. J.

    2013-05-01

    VLF and magnetometer observations can be used to remotely sense the plasmasphere. VLF whistler waves can be used to measure the electron density and magnetic Field Line Resonance (FLR) measurements can be used to measure the mass density. In principle it is then possible to remotely map the plasmasphere with a network of ground-based stations which are also less expensive and more permanent than satellites. The PLASMON project, funded by the EU FP-7 program, is in the process of doing just this. A large number of ground-based observations will be input into a data assimilative framework which models the plasmasphere structure and dynamics. The data assimilation framework combines the Ensemble Kalman Filter with the Dynamic Global Core Plasma Model. Here we simulate the observations from these networks, with appropriate uncertainties, and use them to drive the data assimilation framework to recover the plasmaspheric configuration. We will discuss the level of accuracy that can be achieved.

  15. Evaluating the Accuracy of Plasmasphere Data Assimilation from Ground-Based Observations

    NASA Astrophysics Data System (ADS)

    Jorgensen, A. M.; Lichtenberger, J.; Duffy, J.; Friedel, R. H.; Clilverd, M.; Heilig, B.; Vallante, M.; Manninen, J. K.; Rodger, C. J.; Collier, A.; Reda, J.; Holzworth, R. H.; Ober, D. M.; Boudouridis, A.; Zesta, E.; Chi, P. J.

    2012-12-01

    VLF and magnetometer observations can be used to remotely sense the plasmasphere. VLF whistler waves can be used to measure the electron density and magnetic Field Line Resonance (FLR) measurements can be used to measure the mass density. In principle it is then possible to remotely map the plasmasphere with a network of ground-based stations which are also less expensive and more permanent than satellites. The PLASMON project, funded by the EU FP-7 program, is in the process of doing just this. A large number of ground-based observations will be input into a data assimilative framework which models the plasmasphere structure and dynamics. The data assimilation framework combines the Ensemble Kalman Filter with the Dynamic Global Core Plasma Model. Here we simulate the observations from these networks, with appropriate uncertainties, and use them to drive the data assimilation framework to recover the plasmaspheric configuration. We will discuss the level of accuracy that can be achieved.

  16. Evaluating the Accuracy of Plasmasphere Data Assimilation from Ground-Based Observations

    NASA Astrophysics Data System (ADS)

    Jorgensen, Anders M.; Lichtenberger, Janos; Duffy, Jared; Friedel, Reiner; Clilverd, Mark; Heilig, Balazs; Vellante, Massimo; Raita, Tero; Rodger, Craig; Collier, Andrew; Reda, Jan; Holzworth, Robert; Ober, Daniel; Boudouridis, Athanasios; Zesta, Eftyhia; Chi, Peter J.

    2013-04-01

    VLF and magnetometer observations can be used to remotely sense the plasmasphere. VLF whistler waves can be used to measure the electron density and magnetic Field Line Resonance (FLR) measurements can be used to measure the mass density. In principle it is then possible to remotely map the plasmasphere with a network of ground-based stations which are also less expensive and more permanent than satellites. The PLASMON project, funded by the EU FP-7 program, is in the process of doing just this. A large number of ground-based observations will be input into a data assimilative framework which models the plasmasphere structure and dynamics. The data assimilation framework combines the Ensemble Kalman Filter with the Dynamic Global Core Plasma Model. Here we simulate the observations from these networks, with appropriate uncertainties, and use them to drive the data assimilation framework to recover the plasmaspheric configuration. We will discuss the level of accuracy that can be achieved.

  17. Measuring glacier surface temperatures with ground-based thermal infrared imaging

    NASA Astrophysics Data System (ADS)

    Aubry-Wake, Caroline; Baraer, Michel; McKenzie, Jeffrey M.; Mark, Bryan G.; Wigmore, Oliver; Hellström, Robert È.; Lautz, Laura; Somers, Lauren

    2015-10-01

    Spatially distributed surface temperature is an important, yet difficult to observe, variable for physical glacier melt models. We utilize ground-based thermal infrared imagery to obtain spatially distributed surface temperature data for alpine glaciers. The infrared images are used to investigate thermal microscale processes at the glacier surface, such as the effect of surface cover type and the temperature gradient at the glacier margins on the glacier's temperature dynamics. Infrared images were collected at Cuchillacocha Glacier, Cordillera Blanca, Peru, on 23-25 June 2014. The infrared images were corrected based on ground truth points and local meteorological data. For the control points, the Pearson's correlation coefficient between infrared and station temperatures was 0.95. The ground-based infrared camera has the potential for greatly improving glacier energy budget studies, and our research shows that it is critical to properly correct the thermal images to produce robust, quantifiable data.

  18. Study on the data matching of ground-based radar and laser point cloud

    NASA Astrophysics Data System (ADS)

    Qiu, Zhiwei; Wang, Chenxi; Yue, Jianping

    2016-07-01

    Due to the unique imaging approach for ground-based radar, identification and classification in observation area is very difficult. In order to improve the accuracy of the calculation and application combine with other data resource. it is necessary to implement data matching of radar images and 3D laser point cloud. First, the 3D cloud should to be transformed to orthographic maps, and then the horizontal rotation and orbit attitude angle parameters would be estimated for similarity transformation according to the characteristics such as common points and lines. Finally, the same reference point of the ground-based SAR data and cloud data is employed to accomplished in a two-dimensional coordinate system (called local common coordinate system).

  19. Infrared ground-based astronomy with the Hughes 256 X 256 PtSi array

    NASA Technical Reports Server (NTRS)

    Fowler, A.; Joyce, R.; Gatley, I.; Gates, J.; Herring, J.

    1989-01-01

    It is shown that large format PtSi Schottky diode infrared arrays, the Hughes 256 X 256 hybrid Schottky array in particular, are competitive alternatives to the smaller format photovoltaic arrays for ground-based astronomy. The modest quantum efficiency of the PtSi compared to the photovoltaic devices is more than compensated for by the larger format. The use of hybrid technology yields effective fill factors of nearly 100 percent, and the low dark current, noise, excellent imaging characteristics, cost, and solid nitrogen operating temperature add to the effectiveness of this array for ground-based imaging. In addition to discussing the characteristics of this array, researchers present laboratory test data and astronomical results achieved at Kitt Peak.

  20. Description of the Large-Gap Magnetic Suspension System (LGMSS) ground based experiment

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J.

    1991-01-01

    An overview of the Large Gap Magnetic Suspension System (LGMSS) ground-based experiment is provided. A description of the experiment, as originally defined, and the experiment objectives and potential applications of the technology resulting from the experiment are presented. Also, the results of two studies which were conducted to investigate the feasibility of implementing the experiment are presented and discussed. Finally, a description of the configuration which was selected for the experiment is described, and a summary of the paper is presented.

  1. The response of a ground-based antenna to variations of ionospheric potential

    NASA Astrophysics Data System (ADS)

    Tammet, Kh. F.

    Analytical and numerical models are used to study the response of a ground-based atmospheric electric antenna to ionospheric potential variations. The three-term Schweidler-Gish formula is used to describe the vertical profile of conductivity. It is shown that the different inertia of the volume discharge redistribution in the vertical column can lead to a phase shift between the two antenna signals.

  2. The crop growth research chamber: A ground-based facility for CELSS research

    NASA Technical Reports Server (NTRS)

    Bubenheim, David L.

    1990-01-01

    A ground based facility for the study of plant growth and development under stringently controlled environments is being developed by the Closed Ecological Life Support System (CELSS) program at the Ames Research Center. Several Crop Growth Research Chambers (CGRC) and laboratory support equipment provide the core of this facility. The CGRC is a closed (sealed) system with a separate recirculating atmosphere and nutrient delivery systems. The atmospheric environment, hydroponic environment, systems controls, and data acquisition are discussed.

  3. Metrology of ground-based satellite validation: co-location mismatch and smoothing issues of total ozone comparisons

    NASA Astrophysics Data System (ADS)

    Verhoelst, T.; Granville, J.; Hendrick, F.; Köhler, U.; Lerot, C.; Pommereau, J.-P.; Redondas, A.; Van Roozendael, M.; Lambert, J.-C.

    2015-12-01

    Comparisons with ground-based correlative measurements constitute a key component in the validation of satellite data on atmospheric composition. The error budget of these comparisons contains not only the measurement errors but also several terms related to differences in sampling and smoothing of the inhomogeneous and variable atmospheric field. A versatile system for Observing System Simulation Experiments (OSSEs), named OSSSMOSE, is used here to quantify these terms. Based on the application of pragmatic observation operators onto high-resolution atmospheric fields, it allows a simulation of each individual measurement, and consequently, also of the differences to be expected from spatial and temporal field variations between both measurements making up a comparison pair. As a topical case study, the system is used to evaluate the error budget of total ozone column (TOC) comparisons between GOME-type direct fitting (GODFITv3) satellite retrievals from GOME/ERS2, SCIAMACHY/Envisat, and GOME-2/MetOp-A, and ground-based direct-sun and zenith-sky reference measurements such as those from Dobsons, Brewers, and zenith-scattered light (ZSL-)DOAS instruments, respectively. In particular, the focus is placed on the GODFITv3 reprocessed GOME-2A data record vs. the ground-based instruments contributing to the Network for the Detection of Atmospheric Composition Change (NDACC). The simulations are found to reproduce the actual measurements almost to within the measurement uncertainties, confirming that the OSSE approach and its technical implementation are appropriate. This work reveals that many features of the comparison spread and median difference can be understood as due to metrological differences, even when using strict co-location criteria. In particular, sampling difference errors exceed measurement uncertainties regularly at most mid- and high-latitude stations, with values up to 10 % and more in extreme cases. Smoothing difference errors only play a role in the

  4. Reliability-centered maintenance for ground-based large optical telescopes and radio antenna arrays

    NASA Astrophysics Data System (ADS)

    Marchiori, G.; Formentin, F.; Rampini, F.

    2014-07-01

    In the last years, EIE GROUP has been more and more involved in large optical telescopes and radio antennas array projects. In this frame, the paper describes a fundamental aspect of the Logistic Support Analysis (LSA) process, that is the application of the Reliability-Centered Maintenance (RCM) methodology for the generation of maintenance plans for ground-based large optical telescopes and radio antennas arrays. This helps maintenance engineers to make sure that the telescopes continue to work properly, doing what their users require them to do in their present operating conditions. The main objective of the RCM process is to establish the complete maintenance regime, with the safe minimum required maintenance, carried out without any risk to personnel, telescope and subsystems. At the same time, a correct application of the RCM allows to increase the cost effectiveness, telescope uptime and items availability, and to provide greater understanding of the level of risk that the organization is managing. At the same time, engineers shall make a great effort since the initial phase of the project to obtain a telescope requiring easy maintenance activities and simple replacement of the major assemblies, taking special care on the accesses design and items location, implementation and design of special lifting equipment and handling devices for the heavy items. This maintenance engineering framework is based on seven points, which lead to the main steps of the RCM program. The initial steps of the RCM process consist of: system selection and data collection (MTBF, MTTR, etc.), definition of system boundaries and operating context, telescope description with the use of functional block diagrams, and the running of a FMECA to address the dominant causes of equipment failure and to lay down the Critical Items List. In the second part of the process the RCM logic is applied, which helps to determine the appropriate maintenance tasks for each identified failure mode. Once

  5. Suborbital Reusable Launch Vehicles as an Opportunity to Consolidate and Calibrate Ground Based and Satellite Instruments

    NASA Astrophysics Data System (ADS)

    Papadopoulos, K.

    2014-12-01

    XCOR Aerospace, a commercial space company, is planning to provide frequent, low cost access to near-Earth space on the Lynx suborbital Reusable Launch Vehicle (sRLV). Measurements in the external vacuum environment can be made and can launch from most runways on a limited lead time. Lynx can operate as a platform to perform suborbital in situ measurements and remote sensing to supplement models and simulations with new data points. These measurements can serve as a quantitative link to existing instruments and be used as a basis to calibrate detectors on spacecraft. Easier access to suborbital data can improve the longevity and cohesiveness of spacecraft and ground-based resources. A study of how these measurements can be made on Lynx sRLV will be presented. At the boundary between terrestrial and space weather, measurements from instruments on Lynx can help develop algorithms to optimize the consolidation of ground and satellite based data as well as assimilate global models with new data points. For example, current tides and the equatorial electrojet, essential to understanding the Thermosphere-Ionosphere system, can be measured in situ frequently and on short notice. Furthermore, a negative-ion spectrometer and a Faraday cup, can take measurements of the D-region ion composition. A differential GPS receiver can infer the spatial gradient of ionospheric electron density. Instruments and optics on spacecraft degrade over time, leading to calibration drift. Lynx can be a cost effective platform for deploying a reference instrument to calibrate satellites with a frequent and fast turnaround and a successful return of the instrument. A calibrated reference instrument on Lynx can make collocated observations as another instrument and corrections are made for the latter, thus ensuring data consistency and mission longevity. Aboard a sRLV, atmospheric conditions that distort remotely sensed data (ground and spacecraft based) can be measured in situ. Moreover, an

  6. Radiative Energetics of Mineral Dust Aerosols from Ground-Based Measurements

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee; Hansell, Richard A.

    2011-01-01

    Airborne dust aerosols worldwide contribute a significant part to air quality problems and, to some extent, regional climatic issues (e.g., radiative forcing, hydrological cycle, and primary biological productivity in oceans). Evaluating the direct solar radiative effect of dust aerosols is relatively straightforward due in part to the relatively large SIN ratio in broadband irradiance measurements. The longwave (LW) impact, on the other hand, is rather difficult to ascertain since the measured dust signal level (approx.10 W/sq m) is on the same order as the instrumental uncertainties. Although the magnitude of the LW impact is much smaller than that of the shortwave (SW), it can still have a noticeable influence on the energy distribution of Earth-atmosphere system, particularly due to the strong light-absorptive properties commonly found in many terrestrial minerals. The current effort is part of an ongoing research study to perform a global assessment of dust direct aerosol radiative effects (DARE) during major field deployments of key dust source regions worldwide. In this work we present results stemming from two previous field deployments: the 2006 NASA African Monsoon Multidisciplinary Activities and the 2008 Asian Monsoon Years, both utilizing NASA Goddard's mobile ground-based facility. The former study focused on transported Saharan dust at Sal (16.73degN, 22.93degW), Cape Verde along the west coast of Africa while the latter focused on Asian dust at Zhangye (39.082degN, 100.276degE), China near the source between the Taklimakan and Gobi deserts. Due to the compelling variability in spatial and temporal scale of dust properties during field experiments, a deterministic I-D radiative transfer model constrained by local measurements (i.e., spectral photometry/interferometry and lidar for physical/microphysical, mineralogy, and single-scattering properties) is employed to evaluate dust's local instantaneous SW/LW DARE both at the surface and at the top of

  7. Dynamics of equatorial spread F using ground-based optical and radar measurements

    NASA Astrophysics Data System (ADS)

    Chapagain, Narayan P.

    The Earth's equatorial ionosphere most often shows the occurrence of large plasma density and velocity fluctuations with a broad range of scale sizes and amplitudes. These night time ionospheric irregularities in the F-region are commonly referred to as equatorial spread F (ESF) or plasma bubbles (EPBs). This dissertation focuses on analysis of ground-based optical and radar measurements to investigate the development and dynamics of ESF, which can significantly disrupt radio communication and GPS navigation systems. OI (630.0 nm) airglow image data were obtained by the Utah State University all-sky CCD camera, primarily during the equinox period, from three different longitudinal sectors under similar solar flux conditions: Christmas Island in the Central Pacific Ocean, Ascension Island in South Atlantic, and Brasilia and Cariri in Brazil. Well-defined magnetic field-aligned depletions were observed from each of these sites enabling detailed measurements of their morphology and dynamics. These data have also been used to investigate day-to-day and longitudinal variations in the evolution and distribution of the plasma bubbles, and their nocturnal zonal drift velocities. In particular, comparative optical measurements at different longitudinal sectors illustrated interesting findings. During the post midnight period, the data from Christmas Island consistently showed nearly constant eastward bubble velocity at a much higher value (˜80 m/s) than expected, while data from Ascension Island exhibited a most unusual shear motion of the bubble structure, up to 55 m/s, on one occasion with westward drift at low latitude and eastward at higher latitudes, evident within the field of view of the camera. In addition, long-term radar observations during 1996-2006 from Jicamarca, Peru have been used to study the climatology of post-sunset ESF irregularities. Results showed that the spread F onset times did not change much with solar flux and that their onset heights increased

  8. Suitability of ground-based SfM-MVS for monitoring glacial and periglacial processes

    NASA Astrophysics Data System (ADS)

    Piermattei, Livia; Carturan, Luca; de Blasi, Fabrizio; Tarolli, Paolo; Dalla Fontana, Giancarlo; Vettore, Antonio; Pfeifer, Norbert

    2016-05-01

    Photo-based surface reconstruction is rapidly emerging as an alternative survey technique to lidar (light detection and ranging) in many fields of geoscience fostered by the recent development of computer vision algorithms such as structure from motion (SfM) and dense image matching such as multi-view stereo (MVS). The objectives of this work are to test the suitability of the ground-based SfM-MVS approach for calculating the geodetic mass balance of a 2.1 km2 glacier and for detecting the surface displacement of a neighbouring active rock glacier located in the eastern Italian Alps. The photos were acquired in 2013 and 2014 using a digital consumer-grade camera during single-day field surveys. Airborne laser scanning (ALS, otherwise known as airborne lidar) data were used as benchmarks to estimate the accuracy of the photogrammetric digital elevation models (DEMs) and the reliability of the method. The SfM-MVS approach enabled the reconstruction of high-quality DEMs, which provided estimates of glacial and periglacial processes similar to those achievable using ALS. In stable bedrock areas outside the glacier, the mean and the standard deviation of the elevation difference between the SfM-MVS DEM and the ALS DEM was -0.42 ± 1.72 and 0.03 ± 0.74 m in 2013 and 2014, respectively. The overall pattern of elevation loss and gain on the glacier were similar with both methods, ranging between -5.53 and + 3.48 m. In the rock glacier area, the elevation difference between the SfM-MVS DEM and the ALS DEM was 0.02 ± 0.17 m. The SfM-MVS was able to reproduce the patterns and the magnitudes of displacement of the rock glacier observed by the ALS, ranging between 0.00 and 0.48 m per year. The use of natural targets as ground control points, the occurrence of shadowed and low-contrast areas, and in particular the suboptimal camera network geometry imposed by the morphology of the study area were the main factors affecting the accuracy of photogrammetric DEMs negatively

  9. Tropospheric nitrogen dioxide column retrieval based on ground-based zenith-sky DOAS observations

    NASA Astrophysics Data System (ADS)

    Tack, Frederik; Hendrick, Francois; Goutail, Florence; Fayt, Caroline; Merlaud, Alexis; Pinardi, Gaia; Pommereau, Jean-Pierre; Van Roozendael, Michel

    2014-05-01

    Nitrogen dioxide (NO2) is one of the most important chemically active trace gases in the troposphere. Listed as primary pollutant, it is also a key precursor in the formation of tropospheric ozone, aerosols, and acid rain, and can contribute locally to radiative forcing. The long-term monitoring of this species is therefore of great relevance. Here we present a new method to retrieve tropospheric NO2 vertical column amounts from ground-based zenith-sky measurements of scattered sunlight. It is based on a four-step approach consisting of (1) the DOAS analysis of zenith radiance spectra using a fixed reference spectrum corresponding to low tropospheric NO2 content, (2) the determination of the residual amount in the reference spectrum using a Langley-plot-type method, (3) the removal of the stratospheric content from the daytime total slant column using stratospheric vertical columns measured at twilight and simulated stratospheric NO2 diurnal variation, (4) estimation of the tropospheric vertical columns by dividing the resulting tropospheric slant columns by appropriate air mass factors. The retrieval algorithm is tested on a 2 month dataset acquired from June to July 2009 by the BIRA MAX-DOAS instrument in the framework of the Cabauw (51.97° N, 4.93° E) Intercomparison campaign for Nitrogen Dioxide measuring Instruments (CINDI). The tropospheric vertical column amounts derived from zenith-sky observations are compared to the vertical columns retrieved from the off-axis and direct-sun measurements of the same MAX-DOAS instrument as well as to data of a co-located SAOZ (Système d'Analyse par Observations Zénithales) spectrometer operated by LATMOS. First results show a good agreement between the different data sets with correlation coefficients and slopes close to or larger than 0.85. We observe that the main error sources arise from the uncertainties in the determination of the residual NO2 amount in the reference spectrum, the stratospheric NO2 abundance and

  10. Atomic oxygen interaction with spacecraft materials: Relationship between orbital and ground-based testing for materials certification

    NASA Technical Reports Server (NTRS)

    Cross, Jon B.; Koontz, Steven L.; Lan, Esther H.

    1993-01-01

    The effects of atomic oxygen on boron nitride (BN), silicon nitride (Si3N4), Intelsat 6 solar cell interconnects, organic polymers, and MoS2 and WS2 dry lubricant, were studied in Low Earth Orbit (LEO) flight experiments and in a ground based simulation facility. Both the inflight and ground based experiments employed in situ electrical resistance measurements to detect penetration of atomic oxygen through materials and Electron Spectroscopy for Chemical Analysis (ESCA) analysis to measure chemical composition changes. Results are given. The ground based results on the materials studied to date show good qualitative correlation with the LEO flight results, thus validating the simulation fidelity of the ground based facility in terms of reproducing LEO flight results. In addition it was demonstrated that ground based simulation is capable of performing more detailed experiments than orbital exposures can presently perform. This allows the development of a fundamental understanding of the mechanisms involved in the LEO environment degradation of materials.

  11. Estimating evapotranspiration and drought stress with ground-based thermal remote sensing in agriculture: a review.

    PubMed

    Maes, W H; Steppe, K

    2012-08-01

    As evaporation of water is an energy-demanding process, increasing evapotranspiration rates decrease the surface temperature (Ts) of leaves and plants. Based on this principle, ground-based thermal remote sensing has become one of the most important methods for estimating evapotranspiration and drought stress and for irrigation. This paper reviews its application in agriculture. The review consists of four parts. First, the basics of thermal remote sensing are briefly reviewed. Second, the theoretical relation between Ts and the sensible and latent heat flux is elaborated. A modelling approach was used to evaluate the effect of weather conditions and leaf or vegetation properties on leaf and canopy temperature. Ts increases with increasing air temperature and incoming radiation and with decreasing wind speed and relative humidity. At the leaf level, the leaf angle and leaf dimension have a large influence on Ts; at the vegetation level, Ts is strongly impacted by the roughness length; hence, by canopy height and structure. In the third part, an overview of the different ground-based thermal remote sensing techniques and approaches used to estimate drought stress or evapotranspiration in agriculture is provided. Among other methods, stress time, stress degree day, crop water stress index (CWSI), and stomatal conductance index are discussed. The theoretical models are used to evaluate the performance and sensitivity of the most important methods, corroborating the literature data. In the fourth and final part, a critical view on the future and remaining challenges of ground-based thermal remote sensing is presented. PMID:22922637

  12. Limitation of Ground-based Estimates of Solar Irradiance Due to Atmospheric Variations

    NASA Technical Reports Server (NTRS)

    Wen, Guoyong; Cahalan, Robert F.; Holben, Brent N.

    2003-01-01

    The uncertainty in ground-based estimates of solar irradiance is quantitatively related to the temporal variability of the atmosphere's optical thickness. The upper and lower bounds of the accuracy of estimates using the Langley Plot technique are proportional to the standard deviation of aerosol optical thickness (approx. +/- 13 sigma(delta tau)). The estimates of spectral solar irradiance (SSI) in two Cimel sun photometer channels from the Mauna Loa site of AERONET are compared with satellite observations from SOLSTICE (Solar Stellar Irradiance Comparison Experiment) on UARS (Upper Atmospheric Research Satellite) for almost two years of data. The true solar variations related to the 27-day solar rotation cycle observed from SOLSTICE are about 0.15% at the two sun photometer channels. The variability in ground-based estimates is statistically one order of magnitude larger. Even though about 30% of these estimates from all Level 2.0 Cimel data fall within the 0.4 to approx. 0.5% variation level, ground-based estimates are not able to capture the 27-day solar variation observed from SOLSTICE.

  13. [Development of a ground-based experimental facility for space cultivation of higher plant].

    PubMed

    Guo, S S; Wang, P X; Hou, J D; Ai, W D; Chao, Z G

    2000-02-01

    A ground-based experimental facility was developed for conducting initial ground-based simulation study of Controlled Ecological Life Support System (CELSS). The facility is composed of a main chamber, O2 and CO2 composition control subsystems, plant cultivation subsystem and whole data management subsystem. The growth room, being composed of a inner wall of mirror-face stainless steel, holds a volume of 1.8 m3 and a growing area of 1.2 m2; electronic fluorescent lamps were used as lighting sources and polyvinyl formal was used for root matrixes; the environmental parameters of the growing room such as temperature, relative humidity, O2 concentration, CO2 concentration, lighting period and irradiance intensity and the nutrient parameters such as pH, electrical conductivity, dissolved oxygen concentration, liquid level of nutrient storage tank and flow rate of nutrient were all controlled automatically; all of the above-mentioned parameters can be inspected, collected, stored and printed regularly and dynamically. The results of a combined debugging and preliminary plant cultivation verified that the technical target of the facility had reached its initial design requirements, it can be used to conduct ground-based simulation studies of space cultivation of higher plants.

  14. Integrating ground-based EO data in satellite-based systems

    SciTech Connect

    Jennings, S.V.; Daugherty, P.; Yow, T.G.

    1997-02-01

    Earth observation (EO) and other forms of geo-referenced data are typically thought of as being ``satellite data.`` It is true that the majority of EO data are satellite oriented; thus, most on-line EO data systems are designed primarily for satellite image data. However, there is A small but significant minority of EO data that is not satellite image data; i.e., it is ground-based or terrestrial data Unfortunately, many on-line systems designed for satellite data do not take into account the somewhat different nature of associated ground-based data, Data queries that work most of the time but fail because the system has not taken into account less common data are not robust enough for today`s users. In order to avoid embarrassing problems, EO system designers must be aware of the nature of ground- based data. In this paper we describe some of our insights on this subject in the hope that the designers of other systems may learn from our experience.

  15. Estimating evapotranspiration and drought stress with ground-based thermal remote sensing in agriculture: a review.

    PubMed

    Maes, W H; Steppe, K

    2012-08-01

    As evaporation of water is an energy-demanding process, increasing evapotranspiration rates decrease the surface temperature (Ts) of leaves and plants. Based on this principle, ground-based thermal remote sensing has become one of the most important methods for estimating evapotranspiration and drought stress and for irrigation. This paper reviews its application in agriculture. The review consists of four parts. First, the basics of thermal remote sensing are briefly reviewed. Second, the theoretical relation between Ts and the sensible and latent heat flux is elaborated. A modelling approach was used to evaluate the effect of weather conditions and leaf or vegetation properties on leaf and canopy temperature. Ts increases with increasing air temperature and incoming radiation and with decreasing wind speed and relative humidity. At the leaf level, the leaf angle and leaf dimension have a large influence on Ts; at the vegetation level, Ts is strongly impacted by the roughness length; hence, by canopy height and structure. In the third part, an overview of the different ground-based thermal remote sensing techniques and approaches used to estimate drought stress or evapotranspiration in agriculture is provided. Among other methods, stress time, stress degree day, crop water stress index (CWSI), and stomatal conductance index are discussed. The theoretical models are used to evaluate the performance and sensitivity of the most important methods, corroborating the literature data. In the fourth and final part, a critical view on the future and remaining challenges of ground-based thermal remote sensing is presented.

  16. Flow Characteristics of Tidewater Glaciers in Greenland and Alaska using Ground-Based LiDAR

    NASA Astrophysics Data System (ADS)

    Finnegan, D. C.; Stearns, L. A.; Hamilton, G. S.; O'Neel, S.

    2010-12-01

    LiDAR scanning systems have been employed to characterize and quantify multi-temporal glacier and ice sheet changes for nearly three decades. Until recently, LiDAR scanning systems were limited to airborne and space-based platforms which come at a significant cost to deploy and are limited in spatial and temporal sampling capabilities necessary to compare with in-situ field measurements. Portable ground-based LiDAR scanning systems are now being used as a glaciological tool. We discuss research efforts to employ ground-based near-infrared LiDAR systems at two differing tidewater glacier systems in the spring of 2009; Helheim Glacier in southeast Greenland and Columbia Glacier in southeast Alaska. Preliminary results allow us to characterize short term displacement rates and detailed observations of calving processes. These results highlight the operational limitations and capabilities of commercially available LiDAR systems, and allow us to identify optimal operating characteristics for monitoring small to large-scale tidewater glaciers in near real-time. Furthermore, by identifying the operational limitations of these sensors it allows for optimal design characteristics of new sensors necessary to meet ground-based calibration and validation requirements of ongoing scientific missions.

  17. Comparisons of CH4 ground-based FTIR measurements near Saint Petersburg with GOSAT observations

    NASA Astrophysics Data System (ADS)

    Gavrilov, N. M.; Makarova, M. V.; Poberovskii, A. V.; Timofeyev, Yu. M.

    2014-04-01

    Atmospheric column-average methane mole fractions measured with ground-based Fourier-transform spectroscopy near Saint Petersburg, Russia (59.9° N, 29.8° E, 20 m a.s.l.) are compared with similar data obtained with the Japanese GOSAT (Greenhouse gases Observing SATellite) in the years 2009-2012. Average CH4 mole fractions for the GOSAT data version V01.xx are -15.0 ± 5.4 ppb less than the corresponding values obtained from ground-based measurements (with the standard deviations of biases at 13.0 ± 4.2 ppb). For the GOSAT data version V02.xx, the average values of the differences are -1.9 ± 1.8 ppb with standard deviations of 14.5 ± 1.3 ppb. This verifies that FTIR (Fourier transform infrared) spectroscopic observations near Saint Petersburg have similar biases with GOSAT satellite data as FTIR measurements at other ground-based networks and aircraft CH4 estimations.

  18. Ground-based walking training improves quality of life and exercise capacity in COPD.

    PubMed

    Wootton, Sally L; Ng, L W Cindy; McKeough, Zoe J; Jenkins, Sue; Hill, Kylie; Eastwood, Peter R; Hillman, David R; Cecins, Nola; Spencer, Lissa M; Jenkins, Christine; Alison, Jennifer A

    2014-10-01

    This study was designed to determine the effect of ground-based walking training on health-related quality of life and exercise capacity in people with chronic obstructive pulmonary disease (COPD). People with COPD were randomised to either a walking group that received supervised, ground-based walking training two to three times a week for 8-10 weeks, or a control group that received usual medical care and did not participate in exercise training. 130 out of 143 participants (mean±sd age 69±8 years, forced expiratory volume in 1 s 43±15% predicted) completed the study. Compared to the control group, the walking group demonstrated greater improvements in the St George's Respiratory Questionnaire total score (mean difference -6 points (95% CI -10- -2), p<0.003), Chronic Respiratory Disease Questionnaire total score (mean difference 7 points (95% CI 2-11), p<0.01) and endurance shuttle walk test time (mean difference 208 s (95% CI 104-313), p<0.001). This study shows that ground-based walking training is an effective training modality that improves quality of life and endurance exercise capacity in people with COPD. PMID:25142484

  19. Observation of TGFs onboard "Vernov" satellite and TGEs in ground-based experiments

    NASA Astrophysics Data System (ADS)

    Bogomolov, Vitaly; Panasyuk, Mikhail; Svertilov, Sergey; Garipov, Gali; Iyudin, Anatoly; Klimov, Pavel; Morozenko, Violetta; Maximov, Ivan; Mishieva, Tatiana; Klimov, Stanislav; Pozanenko, Alexey; Rothkaehl, Hanna

    2016-04-01

    "Vernov" satellite with RELEC experiment on-board was launched on 2014 July, 8 into a polar solar-synchronous orbit. The payload includes DRGE gamma-ray spectrometer providing measurements in 10-3000 keV energy range with four detectors directed to atmosphere. Total area of DRGE detectors is ~500 cm2. The data were recorded both in monitoring and gamma by gamma modes with timing accuracy ~15 us. Several TGF candidates with 10-40 gammas in a burst with duration <1ms were detected. Analysis of data from other instruments on-board "Vernov" satellite shows the absence of significant electromagnetic pulses around correspondent time moments. Comparison with WWLLN lightning network data base also indicates that there were no thunderstorms connected with most of detected TGF candidates. Possible connection of these flashes with electron precipitations is discussed. Ground-based experiments, with similar gamma-spectrometers were conducted, to study the spectral, temporal and spatial characteristics of TGEs in 20-3000 keV energy range, as well, as to search the fast hard X-ray and gamma-ray flashes possibly appearing at the moment of lightning. The time of each gamma-quantum interaction was recorded with an ~15 us s accuracy together with detailed spectral data. Measurements were done on the ground at Moscow region, and at mountain altitude in Armenia at Aragatz station. During the time interval covering spring, summer and autumn of 2015 a number of TGEs were detected. Measured low-energy gamma-ray spectra usually contain a set of lines that can be interpreted as radiation of Rn-222 daughter isotopes. The increase of Rn-222 radiation was detected during rainfalls with thunderstorm, as well, as during rainy weather without thunderstorms. Variations of Rn-222 radiation dominate at low energies (<2.6MeV) and must be taken into account in the experiments performed to measure low energy gamma-radiation from the electrons accelerated in thunderclouds. There were no significant

  20. Magnetospheric Response to Interplanetary Field Enhancements: Coordinated Space-based and Ground-based Observations

    NASA Astrophysics Data System (ADS)

    Chi, Peter; Russell, Christopher; Lai, Hairong

    2014-05-01

    In general, asteroids, meteoroids and dust do not interact with the plasma structures in the solar system, but after a collision between fast moving bodies the debris cloud contains nanoscale dust particles that are charged and behave like heavy ions. Dusty magnetic clouds are then accelerated to the solar wind speed. While they pose no threat to spacecraft because of the particle size, the coherency imposed by the magnetization of the cloud allows the cloud to interact with the Earth's magnetosphere as well as the plasma in the immediate vicinity of the cloud. We call these clouds Interplanetary Field Enhancements (IFEs). These IFEs are a unique class of interplanetary field structures that feature cusp-shaped increases and decreases in the interplanetary magnetic field and a thin current sheet. The occurrence of IFEs is attributed to the interaction between the solar wind and dust particles produced in inter-bolide collisions. Previous spacecraft observations have confirmed that IFEs move with the solar wind. When IFEs strike the magnetosphere, they may distort the magnetosphere in several possible ways, such as producing a small indentation, a large scale compression, or a glancing blow. In any event if the IFE is slowed by the magnetosphere, the compression of the Earth's field should be seen in the ground-based magnetic records that are continuously recorded. Thus it is important to understand the magnetospheric response to IFE arrival. In this study, we investigate the IFE structure observed by spacecraft upstream of the magnetosphere and the induced magnetic field perturbations observed by networks of ground magnetometers, including the THEMIS, CARISMA, McMAC arrays in North America and the IMAGE array in Europe. We find that, in a well-observed IFE event on December 24, 2006, all ground magnetometer stations observed an impulse at approximately 1217 UT when the IFE was expected to arrive at the Earth's magnetopause. These ground stations spread across many

  1. Kinematics of 10 Early-Type Galaxies from Hubble Space Telescope and Ground-based Spectroscopy

    NASA Astrophysics Data System (ADS)

    Pinkney, Jason; Gebhardt, Karl; Bender, Ralf; Bower, Gary; Dressler, Alan; Faber, S. M.; Filippenko, Alexei V.; Green, Richard; Ho, Luis C.; Kormendy, John; Lauer, Tod R.; Magorrian, John; Richstone, Douglas; Tremaine, Scott

    2003-10-01

    We present stellar kinematics for a sample of 10 early-type galaxies observed using the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope and the Modular Spectrograph on the MDM Observatory 2.4 m telescope. These observations are a part of an ongoing program to understand the coevolution of supermassive black holes and their host galaxies. Our spectral ranges include either the calcium triplet absorption lines at 8498, 8542, and 8662 Å or the Mg b absorption at 5175 Å. The lines are used to derive line-of-sight velocity distributions (LOSVDs) of the stars using a maximum penalized likelihood method. We use Gauss-Hermite polynomials to parameterize the LOSVDs and find predominantly negative h4 values (boxy distributions) in the central regions of our galaxies. One galaxy, NGC 4697, has significantly positive central h4 (high tail weight). The majority of galaxies have a central velocity dispersion excess in the STIS kinematics over ground-based velocity dispersions. The galaxies with the strongest rotational support, as quantified with vmax/σSTIS, have the smallest dispersion excess at STIS resolution. The best-fitting, general, axisymmetric dynamical models (described in a companion paper) require black holes in all cases, with masses ranging from 106.5 to 109.3 Msolar. We replot these updated masses on the MBH-σ relation and show that the fit to only these 10 galaxies has a slope consistent with the fits to larger samples. The greatest outlier is NGC 2778, a dwarf elliptical with relatively poorly constrained black hole mass. The two best candidates for pseudobulges, NGC 3384 and NGC 7457, do not deviate significantly from the established relation between MBH and σ. Neither do the three galaxies that show the most evidence of a recent merger, NGC 3608, NGC 4473, and NGC 4697. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the

  2. A study of remotely sensed aerosol properties from ground-based sun and sky scanning radiometers

    NASA Astrophysics Data System (ADS)

    Giles, David M.

    . The sensitivity of absorption properties is evaluated and quantified with respect to aerosol retrieval uncertainty. Using clustering analysis, aerosol absorption and size relationships provide a simple method to classify aerosol mixing states and origins and potentially improve aerosol retrievals from ground-based and satellite-based instrumentation.

  3. Ground-based phase wind-up and its application in yaw angle determination

    NASA Astrophysics Data System (ADS)

    Cai, M.; Chen, W.; Dong, D.; Yu, C.; Zheng, Z.; Zhou, F.; Wang, M.; Yue, W.

    2016-08-01

    Ground-based phase wind-up effect (GPWU) is caused by the rotation of receiving antenna. It had been studied and applied in rapidly rotation platforms, such as sounding rocket, guided missile and deep space exploration. In Global Navigation Satellite System high accuracy positioning applications, however, most studies treated it as an error source and focused on eliminating this effect in Precision Point Positioning and Real Time Kinematic (RTK) positioning. The GPWU effect is also sensitive to the rotational status of the antenna, in particular the yaw angle variations. In this paper we explore the feasibility of yaw angle determination of relatively slow rotation platforms based on the GPWU effect. We use the geometry-free carrier phase observations from a RTK base and a moving station receivers to estimate the cumulative yaw angle of the moving platform. Several experiments, including rotating platform tests, vehicle and shipborne tests were carried out. The cumulative errors of rotating platform tests are under 0.38°, indicating good long-term accuracy of the GPWU determined yaw angle. But the RMS are in a range of 11.98° and 17.39°, indicating the errors, such as multipath effect, are not negligible and should be further investigated. The RMS of vehicle and shipborne tests using a base station of 9-11 km are 24.77° and 23.66°. In order to evaluate the influence of the differential ionospheric delay, another vehicle test was carried out using a base station located less than 1 km to the vehicle. The RMS reduces to 15.11°, which gains 39.00 % improvement than before, and demonstrates that the differential ionospheric delay even from a few kilometers long baseline still cannot be neglected. These tests validate the feasibility of GPWU for real-time yaw angle determination. Since this method is able to determine the yaw angle with a minimum one satellite, such a unique feature provides potential applications for attitude determination in the environment with

  4. Ground-Based Geophysical Surveys of the Northeast Greenland Ice Stream

    NASA Astrophysics Data System (ADS)

    Christianson, K.; Jacobel, R. W.; Peters, L. E.; Anandakrishnan, S.; Alley, R. B.; Riverman, K. L.; Muto, A.

    2012-12-01

    On both the Greenland and Antarctic Ice Sheets, mass discharge from the ice interior to the ocean is concentrated in large fast-flowing features, termed outlet glaciers on Greenland and ice streams in West Antarctica. In Greenland, the locations of outlet glaciers are controlled primarily by bedrock topography; in West Antarctica ice streams are dynamic and shift their location based on subglacial hydrology and subglacial sediment conditions, especially on the Siple Coast. The most dramatic exception to this general division of fast-flowing ice masses is the Northeast Greenland Ice Stream (NEGIS), an area of fast flowing ice that initiates near the ice sheet summit and drains much of the ice sheet's northeast quadrant. Although fast-flow likely initiates due to the anomalous presence of high geothermal heat flux, and thus basal melt, near the ice sheet summit, the surface expression of NEGIS is similar to that of a West Antarctic ice stream. Here we present the first ground-based geophysical data ever gathered on the NEGIS. GPS data show the ice stream is characterized by complex variations in surface topography with an amplitude of ~30 m. Ice-penetrating radar (IPR) data show the presence of internal reflecting horizons through the entire ice thickness. Although some deep layers are disturbed, indicating possible basal melt, three zones of the ice stream exhibit internal layer deformation through the entire ice column. Two of these zones correspond to the current shear margins; the third zone's origin is unclear. IPR data also show that the ice stream's location is not solely controlled by the underlying bedrock topography. Evidence for the lack of conformance of streaming flow to bedrock features, and for shifting dynamics (possible paleo-shear margins), reinforces the conclusion that this feature is similar to a West Antarctic ice stream. The presence of a West Antarctic style ice stream in Greenland highlights the ability of the ice sheet to dynamically shift

  5. Evaluation of Anomaly Detection Capability for Ground-Based Pre-Launch Shuttle Operations. Chapter 8

    NASA Technical Reports Server (NTRS)

    Martin, Rodney Alexander

    2010-01-01

    This chapter will provide a thorough end-to-end description of the process for evaluation of three different data-driven algorithms for anomaly detection to select the best candidate for deployment as part of a suite of IVHM (Integrated Vehicle Health Management) technologies. These algorithms were deemed to be sufficiently mature enough to be considered viable candidates for deployment in support of the maiden launch of Ares I-X, the successor to the Space Shuttle for NASA's Constellation program. Data-driven algorithms are just one of three different types being deployed. The other two types of algorithms being deployed include a "nile-based" expert system, and a "model-based" system. Within these two categories, the deployable candidates have already been selected based upon qualitative factors such as flight heritage. For the rule-based system, SHINE (Spacecraft High-speed Inference Engine) has been selected for deployment, which is a component of BEAM (Beacon-based Exception Analysis for Multimissions), a patented technology developed at NASA's JPL (Jet Propulsion Laboratory) and serves to aid in the management and identification of operational modes. For the "model-based" system, a commercially available package developed by QSI (Qualtech Systems, Inc.), TEAMS (Testability Engineering and Maintenance System) has been selected for deployment to aid in diagnosis. In the context of this particular deployment, distinctions among the use of the terms "data-driven," "rule-based," and "model-based," can be found in. Although there are three different categories of algorithms that have been selected for deployment, our main focus in this chapter will be on the evaluation of three candidates for data-driven anomaly detection. These algorithms will be evaluated upon their capability for robustly detecting incipient faults or failures in the ground-based phase of pre-launch space shuttle operations, rather than based oil heritage as performed in previous studies. Robust

  6. Exploring the Diversity of Exoplanet Atmospheres Using Ground-Based Transit Spectroscopy

    NASA Astrophysics Data System (ADS)

    Bean, Jacob

    This is a proposal to fund an observational study of the atmospheres of exoplanets in order to improve our understanding of the nature and origins of these mysterious worlds. The observations will be performed using our new approach for ground-based transit spectroscopy measurements that yields space-telescope quality data. We will also carry out supporting theoretical calculations with new abundance retrieval codes to interpret the measurements. Our project includes a survey of giant exoplanets, and intensive study of especially compelling exoplanets. For the survey, optical and near-infrared transmission spectra, and near-infrared emission spectra will be measured for giant exoplanets with a wide range of estimated temperatures, heavy element abundance, and mass. This comprehensive characterization of a large sample of these planets is now crucial to investigate such issues for their atmospheres as the carbon-to-oxygen ratios and overall metallicities, cause of thermal inversions, and prevalence and nature of high-altitude hazes. The intensive study of compelling individual planets will focus on low-mass (M < 10 M_earth) planets that are feasible targets like the super-Earth GJ1214b, and individual giant planets that display unexpected phenomena like the possibly carbon-rich hot-Jupiter Wasp-12b. The issue that will be addressed for the low-mass planets are the basic compositions of their atmospheres as a boundary condition to constrain models used to infer their bulk compositions. The basic atmospheric compositions of these planets will be determined using transmission spectroscopy, and leveraging its particular sensitivity to the atmospheric scale height. Observations for the project will be carried out with Magellan, Keck, Gemini, and VLT. The team has institutional access to Magellan and Keck, and a demonstrated record of obtaining time on Gemini and VLT for these observations through public channels. This proposal is highly relevant for current and future

  7. A blind deconvolution method for ground based telescopes and Fizeau interferometers

    NASA Astrophysics Data System (ADS)

    Prato, M.; La Camera, A.; Bonettini, S.; Rebegoldi, S.; Bertero, M.; Boccacci, P.

    2015-10-01

    In the case of ground-based telescopes equipped with adaptive optics systems, the point spread function (PSF) is only poorly known or completely unknown. Moreover, an accurate modeling of the PSF is in general not available. Therefore in several imaging situations the so-called blind deconvolution methods, aiming at estimating both the scientific target and the PSF from the detected image, can be useful. A blind deconvolution problem is severely ill-posed and, in order to reduce the extremely large number of possible solutions, it is necessary to introduce sensible constraints on both the scientific target and the PSF. In a previous paper we proposed a sound mathematical approach based on a suitable inexact alternating minimization strategy for minimizing the generalized Kullback-Leibler divergence, assuring global convergence. In the framework of this method we showed that an important constraint on the PSF is the upper bound which can be derived from the knowledge of its Strehl ratio. The efficacy of the approach was demonstrated by means of numerical simulations. In this paper, besides improving the previous approach by the use of a further constraint on the unknown scientific target, we extend it to the case of multiple images of the same target obtained with different PSFs. The main application we have in mind is to Fizeau interferometry. As it is known this is a special feature of the Large Binocular Telescope (LBT). Of the two expected interferometers for LBT, one, LINC-NIRVANA, is forthcoming while the other, LBTI, is already operating and has provided the first Fizeau images, demonstrating the possibility of reaching the resolution of a 22.8 m telescope. Therefore the extension of our blind method to this imaging modality seems to be timely. The method is applied to realistic simulations of imaging both by single mirrors and Fizeau interferometers. Successes and failures of the method in the imaging of stellar fields are demonstrated in simple cases. These

  8. Insight into mechanisms of reduced orthostatic performance after exposure to microgravity: comparison of ground-based and space flight data

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.

    1998-01-01

    Since the beginning of human spaceflight, the value of understanding mechanisms of physiological adaptation to microgravity became apparent to life scientists who were interested in maintining crew health and developing countermeasures agains adverse effects of the mission. However, several characteristics associated the the logistics of spaceflight presented significant limitations to the scientific study of human adaptation to microgravity. Because space missions are so infrequent and involve minimal numbers of crewmembers, meaninful statistical analysis of data are limited. Reproducibility of results from spaceflight experiments is difficult to assess since there are few repeated space missions involving the same crewmembers. Since the emphasis of space missions is placed on operations, experiments are compromised without adequate control over various factors (e.g., time, diet, physical activities, etc.) that can impact measured responses. With the mimimal opportunity to collect spaceflight data, there is a high risk of experiments that simultaneously interfere with other experiments by the increasing demand on the crewmembers to participate in mumerous experiments proposed by multiple investigators. The technology and ability to measure physiological functions necessary to test specific hypotheses can be severely limited by physical space and power constraints of the space enviroment. Finally, technical and logistical aspects of space missions such as launch delays, extended missions, and inflight operational emergencies can significantly compromise the timing and control of experiments. These limitations have stimulated scientists to develop ground-based analogs of microgravity in an effort to investigate the effects of spaceflight on physiological function in a controlled experimental setting. The purpose of this paper is to provide a selected comparison of data collected from ground-based experiments with those obtained from spaceflight in an effort to

  9. Green up onset in the northern high latitude as observed from satellite data and the ground-based camera networks

    NASA Astrophysics Data System (ADS)

    Kobayashi, H.; Nagai, S.; Aoyama, K.; Kumar, A.; Ichii, K.

    2013-12-01

    The climate of the northern high latitude has warmed in the last three decade [Serreze et al., 2000]. However, it is not well understood how the terrestrial ecosystems respond to such abrupt climate changes whether it can cause the increase or decrease in ecosystem productivity. The prolonged drought summer can cause the decrease in the photosynthetic activity [Goetz et al., 2005]. On the other hand, the extended growing season can cause the increase in the plant productivity. The accurate monitoring of the green up onset is, thus, one of the important variables to understand the current and future terrestrial ecosystem response to the warming climate. The decadal changes of green up onset have been estimated by the NOAA/AVHRR normalized difference vegetation index (NDVI) data sets by applying a universal threshold. With the Terra-MODIS and SPOT-VEGETATION data sets, several improved green up onset estimation approaches have been proposed. The digital camera data sets deployed all over the many different ecosystems and regions have enabled to evaluate the satellite green up onset data sets. In this study, we estimated the green up onset using SPOT/VEGETATION data from 1998 to 2011 in northern high latitude. The MODIS phenology products (MCD12Q2) are also obtained. We compared the estimated green up onset results with the ground-based camera data sets. The comparisons show that the green up onset of MODIS phenology was earlier than the ground-based digital camera data sets. Reference Goetz, A. J., A. G. Bunn, G. J. Fiske, and R. A. Houghton (2006), Satellite-observed photosynthetic trends across boreal North America associated with climate and fire disturbance, Proc. Natl. Acad. Sci., 102, 13521-13525. Serreze, M. C., Walsh, J. E., Chapin, F. S., III, Osterkamp, T., Dyurgerov, M., Romanovsky, V., Oechel, W. C., Morison, J., Zhang, T., and Barry, R. G.: 2000, ';Observational evidence of recent change in the northern high latitude environment', Clim. Change 46, 159-207.

  10. Comparison of Cirrus-Cloud Characteristics as Estimated by CALIPSO Space Borne Observations and Ground-Based Lidar Datasets from the inland station Gadanki (13.5 0 N, 79.2 0 E).

    NASA Astrophysics Data System (ADS)

    Vasudevan Nair, Krishnakumar

    Global distribution of cirrus derived from space borne observation has been very elaborately reported by Wang et al., 1996 Mergenthaler et al., 1999, Clark, 2005. But with the arrival of CALIOP on board the CALIPSO mission has improved cirrus reporting and the study on their microphysical properties (Dessler, 2009). Indian Ocean and Indian continent is one of the regions where cirrus occurrence is maximum particularly during the monsoon periods. Most of the study that has reported from this region are derived from the Gadanki ground based station (13.5 0 N, 79.2 0 E). The primary objective of this work is to compare the physical properties of cirrus observed by the ground based and space borne lidar system with respect to the station Gadanki. The current observation is based on the product version 3 data from CALIPSO during the period 2007 to 2010 .This data consist of layer data with horizontal resolution of 5km and a vertical resolution of 300m Both day and night observations are considered for the study. Clouds with optical depth less than 1 and altitude above 8km are only taken in the study to make sure all the observed clouds are cirrus in nature. As clouds with optical depth less than 1 is considered clouds of sub visual, thin and dense clouds are in study Accuracy of the derived cirrus characteristics increases with CAD score. Low CAD score means the accuracy is less or the confidence level in the determined characteristics is less. Clouds with CAD score in the range 70-100 are taken for the study. Since the CALIPSO observations are available continuously along the sub satellite track with a repeat cycle of 16 days. For each orbit cycle the observation track is separated by 1.6 o in longitude. The satellite exactly repeats in a particular point once in 16 days. So in order to get more data grid size of at least 50 and 10 is needed to include more data. In this study the distribution of averaged physical properties inside the grid 50 N to 20 0 N and 60 0 E to

  11. Validation of a high throughput flow cytometric in vitro micronucleus assay including assessment of metabolic activation in TK6 cells.

    PubMed

    Thougaard, Annemette V; Christiansen, Joan; Mow, Tomas; Hornberg, Jorrit J

    2014-12-01

    Genotoxicity is an unacceptable property for new drug candidates and we employ three screening assays during the drug discovery process to identify genotoxicity early and optimize chemical series. One of these methods is the flow cytometric in vitro micronucleus assay for which protocol optimizations have been described recently. Here, we report further validation of the assay in TK6 cells including assessment of metabolic activation. We first optimized assay conditions to allow for testing with and without metabolic activation in parallel in a 96-well plate format. Then, we tested a set of 48 compounds carefully selected to contain known in vivo genotoxins, nongenotoxins and drugs. Avoidance of irrelevant positives, a known issue with mammalian cell-based genotoxicity assays, is important to prevent early deselection of potentially promising compounds. Therefore, we enriched the validation set with compounds that were previously reported to produce irrelevant positive results in mammalian cell-based genotoxicity assays. The resulting dataset was used to set the relevant cut-off values for scoring a compound positive or negative, such that we obtained an optimal balance of high sensitivity (88%) and high specificity (87%). Finally, we tested an additional set of 16 drugs to further probe assay performance and 14 of them were classified correctly. To our knowledge, the present study is the most comprehensive validation of the in vitro flow cytometric micronucleus assay and the first to report parallel assessment with metabolic activation in reasonable throughput. The assay allows for rapidly screening novel compounds for genotoxicity and is therefore well-suited for use in early drug discovery projects. Environ.

  12. First results from ground-based CO2 remote sounding using high-resolution thermal IR laser heterodyne radiometry

    NASA Astrophysics Data System (ADS)

    Hoffmann, Alex; Huebner, Marko; Macleod, Neil; Weidmann, Damien

    2016-04-01

    Over the course of the last decade, the Laser Spectroscopy Group at RAL Space has considerably furthered the passive remote sensing technique of thermal IR Laser Heterodyne Radiometry (LHR), and applied it successfully to the ground-based sounding of atmospheric profiles of a variety of trace gases, including methane. LHR is underpinned by coherent detection technology and ideally shot noise-limited, which can significantly enhance the signal-to-noise ratio of acquired atmospheric spectra over conventional direct detection spectrometers when high spectral (>500,000 resolving power) and high spatial resolutions are needed. These benefits allow probing optimized narrow spectral windows (1 cm-1) with full absorption lineshape information, useful for trace gas vertical profiling. Furthermore, LHR has a high potential for miniaturization into a rugged, unprecedentedly compact package, through hollow waveguide optical integration, facilitating its deployment in ground-based observation networks, as well as on a variety of airborne and spaceborne platforms, whilst retaining its high specifications. This makes LHR well-suited to the remote sounding of key greenhouse gases, in particular carbon dioxide, as observations with high precision and accuracy are crucial to discriminate trends and small variations over a substantial background concentration, and in order to contribute to flux estimations in top-down carbon cycle inversion approaches and anthropogenic emission monitoring. Here, we present a new optical bench-based LHR prototype that has been specifically built to demonstrate CO2 sounding in the thermal IR. The instrument has been coupled to a new permanently installed solar tracker to take a long-term measurement series in solar occultation mode, and to assess the performance of the instrument. We discuss its theoretical performance modelled using an Observation System Simulator, and showcase first results from a 6 months' archive, with observations undergoing

  13. Investigation of the Influence of Microgravity on Transport Mechanisms in a Virtual Spaceflight Chamber: A Ground Based Program

    NASA Technical Reports Server (NTRS)

    Trolinger, James D.; Rangel, Roger; Witherow, William; Rogers, Jan; Lal, Ravindra B.

    1999-01-01

    In January 1992, the IML-1 FES experiment produced a set of classic experimental data and a 40 hour holographic "movie" of an ensemble of spheres in a fluid in microgravity. Because the data are in the form of holograms, we can study the three-dimensional distribution of particles with unprecedented detail by a variety of methods and for a wide variety of interests. The possession of the holographic movie is tantamount to having a complex experiment in space while working in an easily accessible laboratory on earth. The movie contains a vast amount of useful data, including residual g, g-jitter, convection and transport data, and particle fluid interaction data. The information content in the movie is so great that we have scarcely begun to tap into the data that is actually available in the more than 1000 holograms, each containing as much as 1000 megabytes of information. This ground-based project is exploiting this data and the concept of holographic storage of spaceflight data to provide an understanding of the effects of microgravity in materials processing. This paper provides the foundation, objectives, and status of the ground based project. The primary objective of this project is to advance the understanding of microgravity effects on crystal growth, convection in materials processing in the space environment, and complex transport phenomena at low Reynolds numbers. This objective is being achieved both experimentally and theoretically. Experiments are making use of existing holographic data recorded during the IML- I spaceflight. A parallel theoretical effort is providing the models for understanding the particle fields and their physics in the microgravity environment.

  14. Investigating Glacier Surface Conditions using High-Definition Ground Based Infrared Imagery: Insight from the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Aubry-Wake, C.; Baraer, M.; McKenzie, J. M.; Mark, B. G.; Wigmore, O.; Hellstrom, R.

    2014-12-01

    The Cordillera Blanca, Peru, has the highest concentration of glaciers in the tropics. These glaciers, which in some valleys provide up to 70% of the dry season runoff, are rapidly retreating, with potential impacts on water resources. To predict the future changes in water resource in the region, it is important to better understand the processes driving tropical glacier ablation at the headwater of these systems. However, due to the glaciers' high altitude and the remote location, new techniques are needed to investigate these processes. Here we use high-definition ground-based infrared thermal imagery, paired with traditional weather monitoring instruments located on and adjacent to the glacier, to obtain high temporal and spatial resolution temperature maps of the surface of the Cuchillacocha glacier in the Cordillera Blanca. For four consecutive dry seasons (July 2011-2014), 24 to 48 hours of time-lapse imagery (5-30 minute spacing) of the glacier surface and surrounding area were acquired in conjunction with climate data. We compare the spatial and temporal variability of the surface temperature with numerous factors, including the surface conditions (e.g. ice, firn, debris cover, etc.), the thermal gradient at the edge of the glacier and with night time radiative cooling under different atmospheric conditions. The results show that sub-daily fluctuations in runoff from the glacier can be explained in large part by the incoming solar radiation and that the heating not only of the ice surface, but the surround bedrock, are important controls on the rate of meltwater generation. This study shows the potential utility for collecting and analyzing ground based infrared imagery for glacier studies, with implications for hydrologic and water resource applications.

  15. Ground-Based Observations of the Aftermath of the 2010-2011 Great Northern Springtime Storm in Saturn (Invited)

    NASA Astrophysics Data System (ADS)

    Orton, G. S.; Fletcher, L. N.; Fouchet, T.; Fujiyoshi, T.; Greathouse, T. K.; Momary, T.; Yanamandra-Fisher, P. A.

    2013-12-01

    For the first time, a suite of ground-based and spacecraft instruments were available to detect and characterize one of the rare giant convective storms erupting in Saturn's atmosphere. The storm that erupted on 2010 December 5 created an immense thermal and chemical perturbation of the atmosphere. Most of the perturbation of the visible cloud system had abated within a year of the initial eruption, but changes to the atmosphere were evident at thermal infrared wavelengths, and they continue to the present. Here we review the observations from ground-based stations that include NASA's Infrared Telescope Facility (IRTF) and the Subaru Telescope, both at the summit of Mauna Kea, as well as observations from ESO's Very Large Telescope. Evident in the 5-μm spectral window was the clearing of nearly all clouds around and above the 3-bar level of the atmosphere at the latitude of the primary storm. In the intervening two years, imaging in the same window by the IRTF NSFCam2 instrument shows that the cleared region remains prominent and is filling in with a pre-storm cloud cover only very slowly. Most unexpected was the generation of a stratospheric vortex of high temperatures, 'the beacon' (Fletcher et al. 2011 Science 332, 1413). This phenomenon also continues more than two years later and has been tracked using several mid-infrared imaging instruments: VISIR at the VLT, COMICS at Subaru, and MIRSI at the IRTF using moderate-band filters. More precise determination of its vertical distribution was made using the University of Texas Echelon Cross Echelle Spectrograph (TEXES) at the IRTF, targeting specific lines of CH4 and the H2 quadrupole. All of these measurements, taken in concert, show that the heated region of the stratosphere is diminishing in amplitude, expanding in longitude and slowly sinking in altitude.

  16. Temperature Measurements in Venus Upper Atmosphere between 2007 and 2015 from ground-based Infrared Heterodyne Spectroscopy

    NASA Astrophysics Data System (ADS)

    Krause, Pia; Wischnewski, Carolin; Sornig, Manuela; Stangier, Tobias; Sonnabend, Guido; Herrmann, Maren; Wiegand, Moritz; Kostiuk, Theodor; Livengood, Timothy

    2016-04-01

    The structure of Venus atmosphere has been the target of intense studies in the past decade. Among manifold ground based observations, the recent space mission Venus Express in particular has shed light on many open questions concerning the thermal and the dynamical behavior of its atmosphere. A comprehensive understanding of this atmospheric region is still missing. Therefore, direct measurements of atmospheric parameters on various time scales and at different locations on the planet are essential for an understanding and for the validation of global circulation models. Such observations are provided by the infrared heterodyne spectrometers THIS (University of Cologne), HIPWAC (NASA GSFC) and MILAHI (Tohoku University). These instruments fully resolve CO2 non-LTE emission lines for Doppler-wind and temperature retrievals at an pressure level of 1μbar (~110 km) by operating around 10μm. The Long- and short-term variability of daytime temperatures at the ~1μbar level from ground-based observing campaigns between 2007 to 2015 shall be presented. The observations yield a large quantity of temperature measurements at different positions on the planetary disk which allows to map a good part of the dayside of Venus. In addition a detailed study of the interesting but not well understood and only poorly investigated area close to the terminator will be given. Investigations on the general behavior of the temperature and differences between the morning and evening terminators are accomplished. Ongoing analysis of thermal variability and comparison to other observing methods and model calculations are in progress and will be included in the presentation if already available.

  17. Middle atmospheric water vapour measurements obtained at the Maido observatory on la Réunion with a ground-based microwave radiometer

    NASA Astrophysics Data System (ADS)

    Tschanz, Brigitte; Duflot, Valentin; Kämpfer, Niklaus

    2014-05-01

    The ground-based microwave radiometer MIAWARA-C measures middle atmospheric water vapour profiles and is especially designed for the use on campaigns. The instrument is of a compact design, has a simple set up procedure and can be operated remotely. It has been operational for five years and has successfully participated in measurement campaigns under various climatic conditions in Germany, Switzerland, California, Finland and has started to measure on la Réunion (21S, 56E) in September 2013. Under most tropospheric conditions, the instrument can obtain water vapour profiles with a temporal resolution of approximately 2 hours. MIAWARA-C is a reliable instrument and has been validated against similar instruments and satellite experiments. The data sets obtained with MIAWARA-C offer the possibility of comparison with other ground-based instruments and with satellites as well as case studies of atmospheric dynamics. In the southern hemisphere and particularly in the tropical region ground-based measurements of the middle atmosphere are scarce. In MIAWARA-C's water vapour data set a strong seasonal cycle in the stratosphere and signatures of the Semi-Annual Oscillation in the mesosphere are expected. Additionally, the high temporal resolution of the measured data set allows the investigation of short period signals such as diurnal variations. First results after four months of measurements are presented including signatures of the Semi-Annual Oscillation and a first transition to summer condition. In addition, short-term variations observed by MIAWARA-C are analysed.

  18. NEAR-INFRARED THERMAL EMISSION DETECTIONS OF A NUMBER OF HOT JUPITERS AND THE SYSTEMATICS OF GROUND-BASED NEAR-INFRARED PHOTOMETRY

    SciTech Connect

    Croll, Bryce; Albert, Loic; Lafreniere, David; Jayawardhana, Ray; Cushing, Michael; Moutou, Claire; Johnson, John Asher; Bonomo, Aldo S.; Deleuil, Magali; Fortney, Jonathan

    2015-03-20

    We present detections of the near-infrared thermal emission of three hot Jupiters and one brown dwarf using the Wide-field Infrared Camera (WIRCam) on the Canada-France-Hawaii Telescope (CFHT). These include Ks-band secondary eclipse detections of the hot Jupiters WASP-3b and Qatar-1b and the brown dwarf KELT-1b. We also report Y-band, K {sub CONT}-band, and two new and one reanalyzed Ks-band detections of the thermal emission of the hot Jupiter WASP-12b. We present a new reduction pipeline for CFHT/WIRCam data, which is optimized for high precision photometry. We also describe novel techniques for constraining systematic errors in ground-based near-infrared photometry, so as to return reliable secondary eclipse depths and uncertainties. We discuss the noise properties of our ground-based photometry for wavelengths spanning the near-infrared (the YJHK bands), for faint and bright stars, and for the same object on several occasions. For the hot Jupiters WASP-3b and WASP-12b we demonstrate the repeatability of our eclipse depth measurements in the Ks band; we therefore place stringent limits on the systematics of ground-based, near-infrared photometry, and also rule out violent weather changes in the deep, high pressure atmospheres of these two hot Jupiters at the epochs of our observations.

  19. A multi-sensor study of the impact of ground-based glaciogenic seeding on orogrpahic clouds and precipitation

    NASA Astrophysics Data System (ADS)

    Pokharel, Binod

    This dissertation examines reflectivity data from three different radar systems, as well as airborne and ground-based in situ particle imaging data, to study the impact of ground-based glaciogenic seeding on orographic clouds and precipitation formed over the mountains in southern Wyoming. The data for this study come from the AgI Seeding Cloud Impact Investigation (ASCII) field campaign conducted over the Sierra Madre mountains in 2012 (ASCII-12) and over the Medicine Bow mountains in 2013 (ASCII-13) in the context of the Wyoming Weather Modification Pilot Project (WWMPP). The campaigns were supported by a network of ground-based instruments, including a microwave radiometer, two profiling Ka-band Micro Rain Radars (MRRs), a Doppler on Wheels (DOW), rawinsondes, a Cloud Particle Imager, and a Parsivel disdrometer. The University of Wyoming King Air with profiling Wyoming Cloud Radar (WCR) conducted nine successful flights in ASCII-12, and eight flights in ASCII-13. WCR profiles from these flights are combined with those from seven other flights, which followed the same geographically-fixed pattern in 2008-09 (pre-ASCII) over the Medicine Bow range. All sampled storms were relatively shallow, with low-level air forced over the target mountain, and cold enough to support ice initiation by silver iodide (AgI) nuclei in cloud. Three detailed case studies are conducted, each with different atmospheric conditions and different cloud and snow growth properties: one case (21 Feb 2012) is stratiform, with strong winds and cloud droplets too small to enable snow growth by accretion (riming). A second case (13 Feb 2012) contains shallow convective cells. Clouds in the third case study (22 Feb 2012) are stratiform but contain numerous large droplets (mode ~35 microm in diameter), large enough for ice particle growth by riming. These cases and all others, each with a treated period following an untreated period, show that a clear seeding signature is not immediately apparent

  20. Metabolic Expenditures During Extravehicular Activity: Spaceflight versus Ground-based Simulation

    NASA Technical Reports Server (NTRS)

    Klein, Jill; Conkin, Johnny; Gernhardt, Michael; Srinivasan, Ramachandra

    2008-01-01

    In general metabolic rates tend to be higher in NBL than in flight: a) Restraint method dependent; b) Significant differences between the NBL and flight for BRT and APFR (buoyancy effects); and c) No significant difference between NBL and flight for free float and SRMS/SSRMS operations. The total metabolic energy expenditure for a given task and for the EVA as a whole are similar between NBL and flight: a) NBL metabolic rates are higher, but training EVAs are constrained to 5 hours; and b) Flight metabolic rates are lower, but the EVAs are typically an hour or more longer in duration. NBL metabolic rates provide a useful operational tool for flight planning. Quantifying differences and similarities between training and flight improves knowledge for preparation of safe and efficient EVAs.

  1. Prominence activity related to CME observed by SOHO, Yohkoh and ground-based observatories

    NASA Technical Reports Server (NTRS)

    Schmieder, B.; vanDriel-Gesztelyi, L.; Wiik, J. E.; Kucera, T.; Thompson, B.; DeForest, C.; SaintCyr, C.; Simnett, G. M.

    1997-01-01

    Examples of destabilization of prominences and their associated coronal mass ejections (CMEs) are presented. During the 1996 campaigns of multi-wavelength observations with the Solar and Heliospheric Observatory (SOHO), the Yohkoh satellite's soft X-ray telescope (SXT) and the Meudon (France) H alpha spectroheliograph eruptive solar filaments and prominences associated with the CMEs were observed. Two of the observed events showed that CMEs and 'brusques disparitions' (BDs) seem to be consequences of global magnetic field instability.

  2. Ground-based SMART-COMMIT Measurements for Studying Aerosol and Cloud Properties

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee

    2008-01-01

    From radiometric principles, it is expected that the retrieved properties of extensive aerosols and clouds from reflected/emitted measurements by satellite (and/or aircraft) should be consistent with those retrieved from transmitted/emitted radiance observed at the surface. Although space-borne remote sensing observations cover large spatial domain, they are often plagued by contamination of surface signatures. Thus, ground-based in-situ and remote-sensing measurements, where signals come directly from atmospheric constituents, the sun, and/or the Earth-atmosphere interactions, provide additional information content for comparisons that confirm quantitatively the usefulness of the integrated surface, aircraft, and satellite data sets. The development and deployment of SMARTCOMMIT (Surface-sensing Measurements for Atmospheric Radiative Transfer - Chemical, Optical & Microphysical Measurements of In-situ Troposphere) mobile facilities are aimed for the optimal utilization of collocated ground-based observations as constraints to yield higher fidelity satellite retrievals and to determine any sampling bias due to target conditions. To quantify the energetics of the surface-atmosphere system and the atmospheric processes, SMART-COMMIT instruments fall into three categories: flux radiometer, radiance sensor and in-situ probe. In this paper, we will demonstrate the capability of SMART-COMMIT in recent field campaigns (e.g., CRYSTAL-FACE, UAE 2, BASEASIA, NAMMA) that were designed and executed to study the compelling variability in temporal scale of both anthropogenic and natural aerosols (e.g., biomass-burning smoke, airborne dust) and cirrus clouds. We envision robust approaches in which well-collocated ground-based measurements and space-borne observations will greatly advance our knowledge of extensive aerosols and clouds.

  3. CO2 vertical profile retrieval from ground-based IR atmospheric spectra

    NASA Astrophysics Data System (ADS)

    Khosravian, Kobra; Loehnert, Ulrich; Turner, David; Ebell, Kerstin

    2016-04-01

    CO2 vertical profile retrieval from ground-based IR atmospheric spectra In this study, we developed an algorithm for retrieving the CO2 vertical profile from atmospheric ground-based zenith spectra in the mid IR. Providing the CO2 profile from continuous (24h/day) ground-based spectra would be a great potential for studying the carbon cycle, the evaluation of satellite measurements or the assessment of numerical models, which forecast the near-surface CO2 flux. In order to retrieve the CO2 profile, we used observations of the Atmospheric Emitted Radiance Interferometer (AERI) that was installed at the JOYCE (Jülich ObservatorY for Cloud Evolution), Germany in 2012. AERI measures downwelling infrared radiances from 520 cm-1 (3.3 μm) to 3020 cm-1 (19 μm) with a spectral resolution of 1 cm-1 and a temporal resolution of 1 minute. In a first step, we performed sensitivity studies for finding the most-suited spectral bands with highest sensitivity to the mean column amount of CO2 volume mixing ratio (VMR). Then an algorithm, known as AERIoe (Turner and Löhnert 2014), was applied to retrieve the mean column amount of CO2 VMR using simulated radiances in clear sky cases. AERIoe is a variational retrieval algorithm to provide information on Temperature, humidity, trace gases and clouds. The simulated AERI radiances were generated by a line by line radiative transfer model (LBLRTM) using model temperature, humidity and CO2 profile. The retrieval results of mean column amount of CO2 VMR are in good agreement with the true ones. In addition to the mean column amount, we modified AERIoe to retrieve the CO2 vertical profile. First results reveal that there is more than 1 degree of freedom for CO2 profile. We will show results how the retrieval method is refined to optimally exploit the information on the CO2 profile contained in the AERI measurements.

  4. Rainfall Intensity Estimation by Ground-Based Dual-Frequency Microwave Radiometers.

    NASA Astrophysics Data System (ADS)

    Liu, Gin-Rong; Liu, Chung-Chih; Kuo, Tsung-Hua

    2001-06-01

    Many investigators have used satellite data to derive rainfall intensity and to compare them with rain gauge data. However, there has always been a problem: what is the optimal time period for the two different types of data? A set of well-controlled data collected by ground-based dual-frequency microwave radiometers at the National Central University (24.9°N, 121.1°E) in Taiwan between January of 1996 and December of 1997 was used to find the answer. The results show that a 1-h interval would be the optimal time period and that hourly data will provide a better accuracy than other options (5, 10, or 30 min or 2 h). Two algorithms, the differential and the brightness temperature, were established to estimate rainfall intensity using ground-based dual-frequency microwave brightness temperature and rain gauge data. The results show that the root-mean-square error and the correlation coefficient are 0.63 mm h1 and 0.88, respectively, for the differential method, and 0.91 mm h1 and 0.71 for the brightness temperature method. The analysis also shows that because the atmospheric background and environmental influence in the continuous observations are identical, the changes in brightness temperature are only caused from the changes in liquid water content in the air. That probably made the differential method a better choice for rainfall intensity estimation than the brightness temperature method. Moreover, ground-based radiometers measure downwelling radiation from bottom up, and little ice-particle scattering or horizontal inhomogeneity is involved. The results can be compared with retrievals from satellite microwave radiometers for a better understanding of the physics of microwave emission and scattering due to raindrops or ice particles.

  5. Ground-Based Network and Supersite Observations to Complement and Enrich EOS Research

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee; Holben, Brent N.; Welton, Ellsworth J.

    2011-01-01

    Since 1997 NASA has been successfully launching a series of satellites - the Earth Observing System (EOS) - to intensively study, and gain a better understanding of, the Earth as an integrated system. Space-borne remote sensing observations, however, are often plagued by contamination of surface signatures. Thus, ground-based in-situ and remote-sensing measurements, where signals come directly from atmospheric constituents, the sun, and/or the Earth-atmosphere interactions, provide additional information content for comparisons that confirm quantitatively the usefulness of the integrated surface, aircraft, and satellite datasets. Through numerous participations, particularly but not limited to the EOS remote-sensing/retrieval and validation projects over the years, NASA/GSFC has developed and continuously refined ground-based networks and mobile observatories that proved to be vital in providing high temporal measurements, which complement and enrich the satellite observations. These are: the AERO NET (AErosol RObotic NETwork) a federation of ground-based globally distributed network of spectral sun-sky photometers; the MPLNET (Micro-Pulse Lidar NETwork, a similarly organized network of micro-pulse lidar systems measuring aerosol and cloud vertical structure continuously; and the SMART-COMMIT (Surface-sensing Measurements for Atmospheric Radiative Transfer - Chemical, Optical & Microphysical Measurements of In-situ Troposphere, mobile observatories, a suite of spectral radiometers and in-situ probes acquiring supersite measurements. Most MPLNET sites are collocated with those of AERONET, and both networks always support the deployment of SMART-COMMIT worldwide. These data products follow the data structure of EOS conventions: Level-0, instrument archived raw data; Level-1 (or 1.5), real-time data with no (or limited) quality assurance; Level-2, not real high temporal and spectral resolutions. In this talk, we will present NASA/GSFC groundbased facilities, serving

  6. Middle Atmosphere Program. Handbook for MAP. Volume 13: Ground-based Techniques

    NASA Technical Reports Server (NTRS)

    Vincent, R. A. (Editor)

    1984-01-01

    Topics of activities in the middle Atmosphere program covered include: lidar systems of aerosol studies; mesosphere temperature; upper atmosphere temperatures and winds; D region electron densities; nitrogen oxides; atmospheric composition and structure; and optical sounding of ozone.

  7. Experimental validation of Lyot stop apodization in ground-based coronagraphy

    NASA Astrophysics Data System (ADS)

    Cagigas, Miguel A.; Valle, Pedro J.; Cagigal, Manuel P.; Prieto-Blanco, Xesús; Pérez-Garrido, Antonio; Villo-Pérez, Isidro; Femenía, B.; Pérez-Prieto, J. A.; Rodríguez, L. F.; López, R.; Oscoz, A.; Rebolo, R.

    2015-01-01

    We show that the use of apodizing functions at the coronagraph Lyot plane may be useful for improving the image contrast of ground-based coronagraphs. An experimental set-up consisting of a tip-tilt mirror, a coronagraph and a low-noise EMCCD camera was implemented at the William Herschel Telescope. Images were taken in the I band, which meant that the D/r0 value was around 10. Experimental results confirm that, for moderately aberrated wavefronts, our instrument works as theoretically expected, and that the contrast value attained is high enough to provide direct detection of faint companions.

  8. Sensitivity of ground-based Cherenkov telescopes for anisotropics in the cosmic gamma-ray background

    SciTech Connect

    Ripken, Joachim; Horns, Dieter; Elsaesser, Dominik; Mannheim, Karl

    2008-12-24

    Self-annihilating dark matter contributes to the extra galactic very high-energy {gamma}-ray background. This contribution is expected to be anisotropic following the density distribution of non-baryonic dark matter. We explore the possibilities to search for these anisotropies with present and future ground-based gamma-ray experiments like H.E.S.S., MAGIC, or CTA. A multipole-expansion of simulated events is used to investigate the sensitivity for anisotropies detectable with narrow field of view observations.

  9. Protocol for Atomic Oxygen Testing of Materials in Ground-Based Facilities. No. 2

    NASA Technical Reports Server (NTRS)

    Minton, Timothy K.

    1995-01-01

    A second version of standard guidelines is proposed for improving materials testing in ground-based atomic oxygen environments for the purpose of predicting the durability of the tested materials in low Earth orbit (LEO). Accompanying these guidelines are background information and notes about testing. Both the guidelines and the additional information are intended to aid users who wish to evaluate the potential hazard of atomic oxygen in LEO to a candidate space component without actually flying the component in space, and to provide a framework for more consistent atomic oxygen testing in the future.

  10. Quasi-automatic software support for Gaia ground based optical tracking

    NASA Astrophysics Data System (ADS)

    Bouquillon, S.; Barache, C.; Carlucci, T.; Taris, F.; Altmann, M.; Andrei, A. H.; Smart, R.; Steele, Iain A.; Els, Sebastian G.

    2014-07-01

    The ESA Gaia satellite mission will create a catalog of 1 billion stars with unprecedented astrometric precision. To achieve its aim in terms of astrometric precision, a ground based optical tracking campaign (GBOT) of the satellite itself is necessary during the five years of the mission. We present an overview of the GBOT project as a whole in another contribution1 (Altmann et al. in SPIE category "observatory operations"). The present paper will focus more specifically on the software solutions developed by the GBOT group.

  11. Morphology classification of galaxies in CL 0939+4713 using a ground-based telescope image

    NASA Technical Reports Server (NTRS)

    Fukugita, M.; Doi, M.; Dressler, A.; Gunn, J. E.

    1995-01-01

    Morphological classification is studied for galaxies in cluster CL 0939+4712 at z = 0.407 using simple photometric parameters obtained from a ground-based telescope image with seeing of 1-2 arcseconds full width at half maximim (FWHM). By ploting the galaxies in a plane of the concentration parameter versus mean surface brightness, we find a good correlation between the location on the plane and galaxy colors, which are known to correlate with morphological types from a recent Hubble Space Telescope (HST) study. Using the present method, we expect a success rate of classification into early and late types of about 70% or possibly more.

  12. Plant diversity to support humans in a CELSS ground based demonstrator

    NASA Technical Reports Server (NTRS)

    Howe, J. M.; Hoff, J. E.

    1981-01-01

    A controlled ecological life support system (CELSS) for human habitation in preparation for future long duration space flights is considered. The success of such a system depends upon the feasibility of revitalization of food resources and the human nutritional needs which are to be met by these food resources. Edible higher plants are prime candidates for the photoautotrophic components of this system if nutritionally adequate diets can be derived from these plant sources to support humans. Human nutritional requirements information based on current knowledge are developed for inhabitants envisioned in the CELSS ground based demonstrator. Groups of plant products that can provide the nutrients are identified.

  13. Surface features on Mars: Ground-based albedo and radar compared with Mariner 9 topography

    NASA Technical Reports Server (NTRS)

    Frey, H.

    1973-01-01

    Earth-based albedo maps of Mars were compared with Mariner 9 television data and ground-based radar profiles to investigate the nature of the bright and dark albedo features. Little correlation was found except at the boundaries of classical albedo features, where some topographic control is indicated. Wind-blown dust models for seasonal and secular albedo variations are supported, but it is not clear whether the fines are derived from bright or dark parent rock. Mars, like the Earth and Moon, has probably generated two distinct types of crustal material.

  14. Triton's surface properties - A preliminary analysis from ground-based, Voyager photopolarimeter subsystem, and laboratory measurements

    NASA Technical Reports Server (NTRS)

    Buratti, B. J.; Lane, A. L.; Gibson, J.; Burrows, H.; Nelson, R. M.; Bliss, D.; Smythe, W.; Garkanian, V.; Wallis, B.

    1991-01-01

    The surface properties of Triton were investigated using data from the ground-based and Voyager photopolarimeter subsystem (PPS) observations of Triton's phase curve. The results indicate that Triton has a high single-scattering albedo (0.96 +/-0.01 at 0.75 micron) and an unusually compacted surface, possibly similar to that of Europa. Results also suggest that Triton's single-particle phase function and the macroscopically rough character of its surface are similar to those of most other icy satellites.

  15. Liquid Structures and Physical Properties -- Ground Based Studies for ISS Experiments

    NASA Technical Reports Server (NTRS)

    Kelton, K. F.; Bendert, J. C.; Mauro, N. A.

    2012-01-01

    Studies of electrostatically-levitated supercooled liquids have demonstrated strong short- and medium-range ordering in transition metal and alloy liquids, which can influence phase transitions like crystal nucleation and the glass transition. The structure is also related to the liquid properties. Planned ISS experiments will allow a deeper investigation of these results as well as the first investigations of a new type of coupling in crystal nucleation in primary crystallizing liquids, resulting from a linking of the stochastic processes of diffusion with interfacial-attachment. A brief description of the techniques used for ground-based studies and some results relevant to planned ISS investigations are discussed.

  16. Comparing satellite- to ground-based automated and manual cloud coverage observations - a case study

    NASA Astrophysics Data System (ADS)

    Werkmeister, A.; Lockhoff, M.; Schrempf, M.; Tohsing, K.; Liley, B.; Seckmeyer, G.

    2015-05-01

    In this case study we compare cloud fractional cover measured by radiometers on polar satellites (AVHRR) and on one geostationary satellite (SEVIRI) to ground-based manual (SYNOP) and automated observations by a cloud camera (Hemispherical Sky Imager, HSI). These observations took place in Hannover, Germany, and in Lauder, New Zealand, over time frames of 3 and 2 months, respectively. Daily mean comparisons between satellite derivations and the ground-based HSI found the deviation to be 6 ± 14% for AVHRR and 8 ± 16% for SEVIRI, which can be considered satisfactory. AVHRR's instantaneous differences are smaller (2 ± 22%) than instantaneous SEVIRI cloud fraction estimates (8 ± 29%) when compared to HSI due to resolution and scenery effect issues. All spaceborne observations show a very good skill in detecting completely overcast skies (cloud cover ≥ 6 oktas) with probabilities between 92 and 94% and false alarm rates between 21 and 29% for AVHRR and SEVIRI in Hannover, Germany. In the case of a clear sky (cloud cover lower than 3 oktas) we find good skill with detection probabilities between 72 and 76%. We find poor skill, however, whenever broken clouds occur (probability of detection is 32% for AVHRR and 12% for SEVIRI in Hannover, Germany). In order to better understand these discrepancies we analyze the influence of algorithm features on the satellite-based data. We find that the differences between SEVIRI and HSI cloud fractional cover (CFC) decrease (from a bias of 8 to almost 0%) with decreasing number of spatially averaged pixels and decreasing index which determines the cloud coverage in each "cloud-contaminated" pixel of the binary map. We conclude that window size and index need to be adjusted in order to improve instantaneous SEVIRI and AVHRR estimates. Due to its automated operation and its spatial, temporal and spectral resolution, we recommend as well that more automated ground-based instruments in the form of cloud cameras should be installed

  17. Methane Emissions from Bangladesh: Bridging the Gap Between Ground-based and Space-borne Estimates

    NASA Astrophysics Data System (ADS)

    Peters, C.; Bennartz, R.; Hornberger, G. M.

    2015-12-01

    Gaining an understanding of methane (CH4) emission sources and atmospheric dispersion is an essential part of climate change research. Large-scale and global studies often rely on satellite observations of column CH4 mixing ratio whereas high-spatial resolution estimates rely on ground-based measurements. Extrapolation of ground-based measurements on, for example, rice paddies to broad region scales is highly uncertain because of spatio-temporal variability. We explore the use of ground-based river stage measurements and independent satellite observations of flooded area along with satellite measurements of CH4 mixing ratio to estimate the extent of methane emissions. Bangladesh, which comprises most of the Ganges Brahmaputra Meghna (GBM) delta, is a region of particular interest for studying spatio-temporal variation of methane emissions due to (1) broadscale rice cultivation and (2) seasonal flooding and atmospheric convection during the monsoon. Bangladesh and its deltaic landscape exhibit a broad range of environmental, economic, and social circumstances that are relevant to many nations in South and Southeast Asia. We explore the seasonal enhancement of CH4 in Bangladesh using passive remote sensing spectrometer CH4 products from the SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) and the Atmospheric Infrared Sounder (AIRS). The seasonal variation of CH4 is compared to independent estimates of seasonal flooding from water gauge stations and space-based passive microwave water-to-land fractions from the Tropical Rainfall Measuring Mission Microwave Imager (TRMM-TMI). Annual cycles in inundation (natural and anthropogenic) and atmospheric CH4 concentrations show highly correlated seasonal signals. NOAA's HYSPLIT model is used to determine atmospheric residence time of ground CH4 fluxes. Using the satellite observations, we can narrow the large uncertainty in extrapolation of ground-based CH4 emission estimates from rice paddies

  18. Comparison of SMILES ClO profiles with satellite, balloon-borne and ground-based measurements

    NASA Astrophysics Data System (ADS)

    Sagawa, H.; Sato, T. O.; Baron, P.; Dupuy, E.; Livesey, N.; Urban, J.; von Clarmann, T.; de Lange, A.; Wetzel, G.; Connor, B. J.; Kagawa, A.; Murtagh, D.; Kasai, Y.

    2013-12-01

    We evaluate the quality of ClO profiles derived from the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on the International Space Station (ISS). Version 2.1.5 of the level-2 product generated by the National Institute of Information and Communications Technology (NICT) is the subject of this study. Based on sensitivity studies, the systematic error was estimated as 5-10 pptv at the pressure range of 80-20 hPa, 35 pptv at the ClO peak altitude (~ 4 hPa), and 5-10 pptv at pressures ≤ 0.5 hPa for daytime mid-latitude conditions. For nighttime measurements, a systematic error of 8 pptv was estimated for the ClO peak altitude (~ 2 hPa). The SMILES NICT v2.1.5 ClO profiles agree with those derived from another level-2 processor developed by the Japan Aerospace Exploration Agency (JAXA) within the bias uncertainties, except for the nighttime measurements in the low and middle latitude regions where the SMILES NICT v2.1.5 profiles have a negative bias of ~ 30 pptv in the lower stratosphere. This bias is considered to be due to the use of a limited spectral bandwidth in the retrieval process of SMILES NICT v2.1.5, which makes it difficult to distinguish between the weak ClO signal and wing contributions of spectral features outside the bandwidth. In the middle and upper stratosphere outside the polar regions, no significant systematic bias was found for the SMILES NICT ClO profile with respect to data sets from other instruments such as the Aura Microwave Limb Sounder (MLS), the Odin Sub-Millimetre Radiometer (SMR), the Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), and the ground-based radiometer at Mauna Kea, which demonstrates the scientific usability of the SMILES ClO data including the diurnal variations. Inside the chlorine-activated polar vortex, the SMILES NICT v2.1.5 ClO profiles show larger volume mixing ratios by 0.4 ppbv (30%) at 50 hPa compared to those of the JAXA processed profiles. This discrepancy is also

  19. Comments to the Article by Thuillier et al. "The Infrared Solar Spectrum Measured by the SOLSPEC Spectrometer Onboard the International Space Station" on the Interpretation of Ground-based Measurements at the Izaña Site

    NASA Astrophysics Data System (ADS)

    Bolsée, D.; Pereira, N.; Cuevas, E.; García, R.; Redondas, A.

    2016-10-01

    Thuillier et al. ( Solar Phys. 290, 1581, 2015) article compares ATLAS-3 reference composite solar spectral irradiance (SSI) with more recent spatial measurements, as well as ground-based ones, including IRSPERAD. With respect to the IRSPERAD spectrum of Bolsée et al. ( Solar Phys. 289, 2433, 2014), Thuillier et al. (2015) presents an analysis based on a set of meteorological parameters retrieved at the moment of the respective ground-based campaign. This comment is intended to give a new insight to the said analysis which is based upon revised values of the meteorological parameters incorrectly used in Thuillier et al. (2015).

  20. [Evaluation of an obesity prevention intervention which included nutrition education and physical activity applied in public schools of Santiago, Chile].

    PubMed

    Kain, Juliana; Leyton, Bárbara; Concha, Fernando; Weisstaub, Gerardo; Lobos, Luz; Bustos, Nelly; Vio, Fernando

    2