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Sample records for observing system satellites

  1. Spanish Earth Observation Satellite System

    NASA Astrophysics Data System (ADS)

    Borges, A.; Cerezo, F.; Fernandez, M.; Lomba, J.; Lopez, M.; Moreno, J.; Neira, A.; Quintana, C.; Torres, J.; Trigo, R.; Urena, J.; Vega, E.; Vez, E.

    2010-12-01

    The Spanish Ministry of Industry, Tourism and Trade (MITyC) and the Ministry of Defense (MoD) signed an agreement in 2007 for the development of a "Spanish Earth Observation Satellite System" based, in first instance, on two satellites: a high resolution optical satellite, called SEOSAT/Ingenio, and a radar satellite based on SAR technology, called SEOSAR/Paz. SEOSAT/Ingenio is managed by MITyC through the Centre for the Development of Industrial Technology (CDTI), with technical and contractual support from the European Space Agency (ESA). HISDESA T together with the Spanish Instituto Nacional de Técnica Aeroespacial (INTA, National Institute for Aerospace Technology) will be responsible for the in-orbit operation and the commercial operation of both satellites, and for the technical management of SEOSAR/Paz on behalf of the MoD. In both cases EADS CASA Espacio (ECE) is the prime contractor leading the industrial consortia. The ground segment development will be assigned to a Spanish consortium. This system is the most important contribution of Spain to the European Programme Global Monitoring for Environment and Security, GMES. This paper presents the Spanish Earth Observation Satellite System focusing on SEOSA T/Ingenio Programme and with special emphasis in the potential contribution to the ESA Third Party Missions Programme and to the Global Monitoring for Environment and Security initiative (GMES) Data Access.

  2. On the development of earth observation satellite systems

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Subsequent to the launching of the first LANDSAT by NASA, Japan has recognized the importance of data from earth observation satellites, has conducted studies, and is preparing to develop an independent system. The first ocean observation satellite will be launched in 1983, the second in 1985. The first land observation satellite is scheduled to be launched in 1987 and by 1990 Japan intends to have both land and ocean observation systems in regular operation. The association reception and data processing systems are being developed.

  3. The Earth Phenomena Observing System: Intelligent Autonomy for Satellite Operations

    NASA Technical Reports Server (NTRS)

    Ricard, Michael; Abramson, Mark; Carter, David; Kolitz, Stephan

    2003-01-01

    Earth monitoring systems of the future may include large numbers of inexpensive small satellites, tasked in a coordinated fashion to observe both long term and transient targets. For best performance, a tool which helps operators optimally assign targets to satellites will be required. We present the design of algorithms developed for real-time optimized autonomous planning of large numbers of small single-sensor Earth observation satellites. The algorithms will reduce requirements on the human operators of such a system of satellites, ensure good utilization of system resources, and provide the capability to dynamically respond to temporal terrestrial phenomena. Our initial real-time system model consists of approximately 100 satellites and large number of points of interest on Earth (e.g., hurricanes, volcanoes, and forest fires) with the objective to maximize the total science value of observations over time. Several options for calculating the science value of observations include the following: 1) total observation time, 2) number of observations, and the 3) quality (a function of e.g., sensor type, range, slant angle) of the observations. An integrated approach using integer programming, optimization and astrodynamics is used to calculate optimized observation and sensor tasking plans.

  4. Satellite Observation Systems for Polar Climate Change Studies

    NASA Technical Reports Server (NTRS)

    Comiso, Josefino C.

    2012-01-01

    The key observational tools for detecting large scale changes of various parameters in the polar regions have been satellite sensors. The sensors include passive and active satellite systems in the visible, infrared and microwave frequencies. The monitoring started with Tiros and Nimbus research satellites series in the 1970s but during the period, not much data was stored digitally because of limitations and cost of the needed storage systems. Continuous global data came about starting with the launch of ocean color, passive microwave, and thermal infrared sensors on board Nimbus-7 and Synthetic Aperture Radar, Radar Altimeter and Scatterometer on board SeaSat satellite both launched in 1978. The Nimbus-7 lasted longer than expected and provided about 9 years of useful data while SeaSat quit working after 3 months but provided very useful data that became the baseline for follow-up systems with similar capabilities. Over the years, many new sensors were launched, some from Japan Aeronautics and Space Agency (JAXA), some from the European Space Agency (ESA) and more recently, from RuSSia, China, Korea, Canada and India. For polar studies, among the most useful sensors has been the passive microwave sensor which provides day/night and almost all weather observation of the surface. The sensor provide sea surface temperature, precipitation, wind, water vapor and sea ice concentration data that have been very useful in monitoring the climate of the region. More than 30 years of such data are now available, starting with the Scanning Multichannel Microwave Radiometer (SMMR) on board the Nimbus-7, the Special Scanning Microwave/Imager (SSM/I) on board a Defense Meteorological Satellite Program (DMSP) and the Advanced Microwave Scanning Radiometer on board the EOS/ Aqua satellite. The techniques that have been developed to derive geophysical parameters from data provided by these and other sensors and associated instrumental and algorithm errors and validation techniques will be discussed. An important issue is the organization and storage of hundreds of terabytes of data collected by even just a few of these satellite sensors. Advances in mass storage and computer technology have made it possible to overcome many of the collection and archival problems and the availability of comprehensive satellite data sets put together by NASA's Earth Observing System project will be discussed.

  5. Rule-Based System Architecting of Earth Observation Satellite Systems Daniel Selva Valero

    E-print Network

    de Weck, Olivier L.

    1 Rule-Based System Architecting of Earth Observation Satellite Systems by Daniel Selva Valero;2 #12;3 Rule-Based System Architecting of Earth Observation Satellite Systems by Daniel Selva Valero of the Requirements for the Degree of Doctor of Philosophy Abstract System architecting is concerned with exploring

  6. Observing System Simulations for Small Satellite Formations Estimating Bidirectional Reflectance

    NASA Technical Reports Server (NTRS)

    Nag, Sreeja; Gatebe, Charles K.; de Weck, Olivier

    2015-01-01

    The bidirectional reflectance distribution function (BRDF) gives the reflectance of a target as a function of illumination geometry and viewing geometry, hence carries information about the anisotropy of the surface. BRDF is needed in remote sensing for the correction of view and illumination angle effects (for example in image standardization and mosaicing), for deriving albedo, for land cover classification, for cloud detection, for atmospheric correction, and other applications. However, current spaceborne instruments provide sparse angular sampling of BRDF and airborne instruments are limited in the spatial and temporal coverage. To fill the gaps in angular coverage within spatial, spectral and temporal requirements, we propose a new measurement technique: Use of small satellites in formation flight, each satellite with a VNIR (visible and near infrared) imaging spectrometer, to make multi-spectral, near-simultaneous measurements of every ground spot in the swath at multiple angles. This paper describes an observing system simulation experiment (OSSE) to evaluate the proposed concept and select the optimal formation architecture that minimizes BRDF uncertainties. The variables of the OSSE are identified; number of satellites, measurement spread in the view zenith and relative azimuth with respect to solar plane, solar zenith angle, BRDF models and wavelength of reflection. Analyzing the sensitivity of BRDF estimation errors to the variables allow simplification of the OSSE, to enable its use to rapidly evaluate formation architectures. A 6-satellite formation is shown to produce lower BRDF estimation errors, purely in terms of angular sampling as evaluated by the OSSE, than a single spacecraft with 9 forward-aft sensors. We demonstrate the ability to use OSSEs to design small satellite formations as complements to flagship mission data. The formations can fill angular sampling gaps and enable better BRDF products than currently possible.

  7. A view finder control system for an earth observation satellite

    NASA Astrophysics Data System (ADS)

    Steyn, H.

    2004-11-01

    A real time TV view finder is used on-board a low earth orbiting (LEO) satellite to manually select targets for imaging from a ground station within the communication footprint of the satellite. The attitude control system on the satellite is used to steer the satellite using commands from the groundstation and a television camera onboard the satellite will then downlink a television signal in real time to a monitor screen in the ground station. The operator in the feedback loop will be able to manually steer the boresight of the satellite's main imager towards interested target areas e.g. to avoid clouds or correct for any attitude pointing errors. Due to a substantial delay (in the order of a second) in the view finding feedback loop and the narrow field of view of the main imager, the operator has to be assisted by the onboard attitude control system to stabilise and track the target area visible on the monitor screen. This paper will present the extended Kalman filter used to estimate the satellite's attitude angles using quaternions and the bias vector component of the 3-axis inertial rate sensors (gyros). Absolute attitude sensors (i.e. sun, horizon and magnetic) are used to supply the measurement vectors to correct the filter states during the view finder manoeuvres. The target tracking and rate steering reaction wheel controllers to accurately point and stabilise the satellite will be presented. The reference generator for the satellite to target attitude and rate vectors as used by the reaction wheel controllers will be derived.

  8. Rule-based system architecting of Earth observation satellite systems

    E-print Network

    Selva Valero, Daniel

    2012-01-01

    System architecting is concerned with exploring the tradespace of early, high-level, system design decisions with a holistic, value-centric view. In the last few years, several tools and methods have been developed to ...

  9. NASDA's earth observation satellite data archive policy for the earth observation data and information system (EOIS)

    NASA Technical Reports Server (NTRS)

    Sobue, Shin-ichi; Yoshida, Fumiyoshi; Ochiai, Osamu

    1996-01-01

    NASDA's new Advanced Earth Observing Satellite (ADEOS) is scheduled for launch in August, 1996. ADEOS carries 8 sensors to observe earth environmental phenomena and sends their data to NASDA, NASA, and other foreign ground stations around the world. The downlink data bit rate for ADEOS is 126 MB/s and the total volume of data is about 100 GB per day. To archive and manage such a large quantity of data with high reliability and easy accessibility it was necessary to develop a new mass storage system with a catalogue information database using advanced database management technology. The data will be archived and maintained in the Master Data Storage Subsystem (MDSS) which is one subsystem in NASDA's new Earth Observation data and Information System (EOIS). The MDSS is based on a SONY ID1 digital tape robotics system. This paper provides an overview of the EOIS system, with a focus on the Master Data Storage Subsystem and the NASDA Earth Observation Center (EOC) archive policy for earth observation satellite data.

  10. Earth observing satellite: Understanding the Earth as a system

    NASA Technical Reports Server (NTRS)

    Soffen, Gerald

    1990-01-01

    There is now a plan for global studies which include two very large efforts. One is the International Geosphere/Biosphere Program (IGBP) sponsored by the International Council of Scientific Unions. The other initiative is Mission to Planet Earth, an unbrella program for doing three kinds of space missions. The major one is the Earth Observation Satellite (EOS). EOS is large polar orbiting satellites with heavy payloads. Two will be placed in orbit by NASA, one by the Japanese and one or two by ESA. The overall mission measurement objectives of EOS are summarized: (1) the global distribution of energy input to and energy output from the Earth; (2) the structure, state variables, composition, and dynamics of the atmosphere from the ground to the mesopause; (3) the physical and biological structure, state, composition, and dynamics of the land surface, including terrestrial and inland water ecosystems; (4) the rates, important sources and sinks, and key components and processes of the Earth's biogeochemical cycles; (5) the circulation, surface temperature, wind stress, sea state, and the biological activity of the oceans; (6) the extent, type, state, elevation, roughness, and dynamics of glaciers, ice sheets, snow and sea ice, and the liquid equivalent of snow in the global cryosphere; (7) the global rates, amounts, and distribution of precipitation; and (8) the dynamic motions of the Earth (geophysics) as a whole, including both rotational dynamics and the kinematic motions of the tectonic plates.

  11. System architecting of a campaign of earth observing satellites

    E-print Network

    Colson, Justin M

    2008-01-01

    Given the current level of concern over anthropogenic climate change, and the ongoing debate worldwide regarding what action should be taken to reduce and reverse future warming, the ability to collect data on Earth system ...

  12. Candidate configuration trade study, Stellar-inertial Measurement Systems (SIMS) for an Earth Observation Satellite (EOS)

    NASA Technical Reports Server (NTRS)

    Ogletree, G.; Coccoli, J.; Mckern, R.; Smith, M.; White, R.

    1972-01-01

    The results of analytical and simulation studies of the stellar-inertial measurement system (SIMS) for an earth observation satellite are presented. Subsystem design analyses and sensor design trades are reported. Three candidate systems are considered: (1) structure-mounted gyros with structure-mounted star mapper, (2) structure-mounted gyros with gimbaled star tracker, and (3) gimbaled gyros with structure-mounted star mapper. The purpose of the study is to facilitate the decisions pertaining to gimbaled versus structure-mounted gyros and star sensors, and combinations of systems suitable for the EOS satellite.

  13. Stereoscopic observations from meteorological satellites

    NASA Astrophysics Data System (ADS)

    Hasler, A. F.; Mack, R.; Negri, A.

    The capability of making stereoscopic observations of clouds from meteorological satellites is a new basic analysis tool with a broad spectrum of applications. Stereoscopic observations from satellites were first made using the early vidicon tube weather satellites (e.g., Ondrejka and Conover [1]). However, the only high quality meteorological stereoscopy from low orbit has been done from Apollo and Skylab, (e.g., Shenk et al. [2] and Black [3], [4]). Stereoscopy from geosynchronous satellites was proposed by Shenk [5] and Bristor and Pichel [6] in 1974 which allowed Minzner et al. [7] to demonstrate the first quantitative cloud height analysis. In 1978 Bryson [8] and desJardins [9] independently developed digital processing techniques to remap stereo images which made possible precision height measurement and spectacular display of stereograms (Hasler et al. [10], and Hasler [11]). In 1980 the Japanese Geosynchronous Satellite (GMS) and the U.S. GOES-West satellite were synchronized to obtain stereo over the central Pacific as described by Fujita and Dodge [12] and in this paper. Recently the authors have remapped images from a Low Earth Orbiter (LEO) to the coordinate system of a Geosynchronous Earth Orbiter (GEO) and obtained stereoscopic cloud height measurements which promise to have quality comparable to previous all GEO stereo. It has also been determined that the north-south imaging scan rate of some GEOs can be slowed or reversed. Therefore the feasibility of obtaining stereoscopic observations world wide from combinations of operational GEO and LEO satellites has been demonstrated. Stereoscopy from satellites has many advantages over infrared techniques for the observation of cloud structure because it depends only on basic geometric relationships. Digital remapping of GEO and LEO satellite images is imperative for precision stereo height measurement and high quality displays because of the curvature of the earth and the large angular separation of the two satellites. A general solution for accurate height computation depends on precise navigation of the two satellites. Validation of the geosynchronous satellite stereo using high altitude mountain lakes and vertically pointing aircraft lidar leads to a height accuracy estimate of +/- 500 m for typical clouds which have been studied. Applications of the satellite stereo include: 1) cloud top and base height measurements, 2) cloud-wind height assignment, 3) vertical motion estimates for convective clouds (Mack et al. [13], [14]), 4) temperature vs. height measurements when stereo is used together with infrared observations and 5) cloud emissivity measurements when stereo, infrared and temperature sounding are used together (see Szejwach et al. [15]). When true satellite stereo image pairs are not available, synthetic stereo may be generated. The combination of multispectral satellite data using computer produced stereo image pairs is a dramatic example of synthetic stereoscopic display. The classic case uses the combination of infrared and visible data as first demonstrated by Pichel et al. [16]. Hasler et at. [17], Mosher and Young [18] and Lorenz [19], have expanded this concept to display many channels of data from various radiometers as well as real and simulated data fields. A future system of stereoscopic satellites would be comprised of both low orbiters (as suggested by Lorenz and Schmidt [20], [19]) and a global system of geosynchronous satellites. The low earth orbiters would provide stereo coverage day and night and include the poles. An optimum global system of stereoscopic geosynchronous satellites would require international standarization of scan rate and direction, and scan times (synchronization) and resolution of at least 1 km in all imaging channels. A stereoscopic satellite system as suggested here would make an extremely important contribution to the understanding and prediction of the atmosphere.

  14. Stereoscopic observations from meteorological satellites

    NASA Technical Reports Server (NTRS)

    Hasler, A. F.; Negri, A.; Mack, R.

    1982-01-01

    Stereo cloud top height measurements, accurate to within + or - 500 m, have been performed using operational weather satellites. The stereo has been demonstrated using various combinations of GEO and LEO satellites, and the use of synthetic stereo was considered. Stereo can be done over most of the earth (60 deg S to 60 deg N) during the day; at higher latitudes and at night, stereo can be done using two LEOs if the proper coincidences occur. The usefulness of stereo cloud top height measurements has been demonstrated by many studies of convective storm cloud systems. Recommendations relating to short, medium, and long term planning regarding stereo observations from meteorological satellites are outlined.

  15. Ionospheric Simulation System for Satellite Observations and Global Assimilative Model Experiments - ISOGAME

    NASA Technical Reports Server (NTRS)

    Pi, Xiaoqing; Mannucci, Anthony J.; Verkhoglyadova, Olga; Stephens, Philip; Iijima, Bryron A.

    2013-01-01

    Modeling and imaging the Earth's ionosphere as well as understanding its structures, inhomogeneities, and disturbances is a key part of NASA's Heliophysics Directorate science roadmap. This invention provides a design tool for scientific missions focused on the ionosphere. It is a scientifically important and technologically challenging task to assess the impact of a new observation system quantitatively on our capability of imaging and modeling the ionosphere. This question is often raised whenever a new satellite system is proposed, a new type of data is emerging, or a new modeling technique is developed. The proposed constellation would be part of a new observation system with more low-Earth orbiters tracking more radio occultation signals broadcast by Global Navigation Satellite System (GNSS) than those offered by the current GPS and COSMIC observation system. A simulation system was developed to fulfill this task. The system is composed of a suite of software that combines the Global Assimilative Ionospheric Model (GAIM) including first-principles and empirical ionospheric models, a multiple- dipole geomagnetic field model, data assimilation modules, observation simulator, visualization software, and orbit design, simulation, and optimization software.

  16. An analysis of the upper atmospheric wind observed by LOGACS. [satellite Low-G Accelerometer Calibration System

    NASA Technical Reports Server (NTRS)

    Wu, S. T.; Matsushita, S.; Devries, L. L.

    1974-01-01

    Wind velocities at 140 to 200 km altitude were observed by a low-g accelerometer calibration system (LOGACS) flown on an Agena satellite during a geomagnetic storm. An interesting wind reversal observed by the satellite at auroral latitudes is satisfactorily explained by the neutral air motion caused by the E x B drift deduced from the ground-based geomagnetic data recorded at stations near the meridian of the satellite orbit.

  17. Data Dissemination System Status and Plan for Jaxa's Earth Observation Satellite Data

    NASA Astrophysics Data System (ADS)

    Fuda, M.; Miura, S.

    2012-12-01

    1. INTRODUCTION JAXA is Japan's national aerospace agency and responsible for research, technology development and the launch of satellites into orbit, and is involved in many more advanced missions, such as asteroid exploration and possible manned exploration of the Moon. Since 1978, JAXA started to disseminate earth observation data acquired by satellites to researchers and those data scene became more than two Million scenes in 2011. This paper focuses on the status and future plan for JAXA's Data Dissemination System for those data. 2. STATUS JAXA is Japan's national aerospace agency and responsible for research, technology development and the launch of satellites into orbit. In October 1978, JAXA opened the Earth Observation Center (EOC) and started to archive and disseminate earth observation data acquired by multiple satellites. 2.1. Target data Currently, the disseminated data includes "JAXA's satellite/sensor data" and "non-JAXA's satellite/sensor data", as shown in Table 2-1. In 2011, the total disseminated data scene became more than two Million scenes. 2.2. Data Dissemination Guideline The JAXA basic data dissemination guideline is a free for researchers and specific agencies. JAXA has two approaches for dissemination. One is that the data is distributed for specific agencies by Mission Operation Systems (MOS). Each project has its own MOS, for example, GCOM-W1 has a GCOM-W1 MOS. Another is that the data is disseminated for many researchers by Data Distribution Systems. Now JAXA has three Data Distribution systems, EOIS, AUIG and GCOM-W1DPSS. Table 2-1 : Disseminated earth observation data from JAXA's facility Satellite Sensor Processing Level ALOS AVNIR-2 Level 1 PRISM Level 1 PALSAR Level 1 TRMM PR Level 1, 2, 3 CMB Level 1, 2, 3 TMI Level 1, 2, 3 VIR Level 1, 2, 3 Aqua AMSR-E Level 1, 2, 3 ADEOS-II AMSR Level 1, 2, 3 GLI-1km Level 1, 2, 3 GLI-250m Level 1, 2, 3 JERS-1 OSW Level 0, 1, 2 OVN Level 0, 1, 2, 5 SAR Level 1, 2 ADEOS AVNIR Level 1 OCTS Level 1, 2, 3 MOS-1b, -1 MES Level 0, 1, 2 VTI Level 0, 1, 2 GOSAT TANSO Level 1, 2, 3, 4 3. FUTURE PLAN For global earth observation spacecrafts, JAXA is now developing two dissemination systems, G-Portal and CATS-I. G-Portal will replace the EOIS and GCOM-W1DPSS including ALOS catalogue in AUIG. Users will be able to get the products of several spacecrafts in one stop service. G-Portal will be main dissemination system of the products for researches in GPM, GCOM-C1 and EarthCARE era. Other hand, CATS-I will disseminate Earth Observation product's catalogue for Japanese domestic key agencies, for example, Cabinet Office. CATS-I will also disseminate the catalogue for world key agencies and harvest the catalogue from other agencies with Catalogue Service for Web (CSW). JAXA will enlarge these G-Portal and CATS-I for future earth observation spacecrafts and these systems will be meet the demands of future users.

  18. Marine Stratus Cloud Objects Simulated by a Cloud-Resolving Model and Observed by Earth Observing System Satellite

    NASA Astrophysics Data System (ADS)

    Luo, Y.; Xu, K.

    2005-05-01

    Using a new approach proposed by Xu et al. (2005), 2162 stratus cloud objects are diagnosed using the Clouds and the Earth's Radiant Energy System (CERES) Single Scanner Footprint (SSF) product on board the Tropical Rainfall Measuring Mission (TRMM) satellite during January-August 1998 at three regions of east Pacific: north subtropical, east equatorial, and south subtropical. A cloud object is identified as a contiguous region of the Earth composed of individual satellite footprints within a single dominant cloud-system type. To be identified as a stratus cloud object, the cloud top height must be less than 3 km and cloud fraction is 0.99-1.00. The probability density functions (PDFs) of several observed and retrieved fields from the CERES SSF product are found to be different among the three regions. Two versions of a cloud-resolving model (CRM), which includes either a two-moment or a one-moment microphysics scheme, are used to simulate a number of the observed marine stratus cloud objects. Number concentrations of cloud droplets and rain drops, in addition to their mixing ratios, are predicted by the CRM version with the two-moment microphysics scheme while they are not predicted by the CRM version with the one-moment microphysics scheme. ECMWF meteorological fields matched with the instantaneous satellite cloud-object data are used to drive the CRM, i.e. to provide initial atmospheric state, large-scale total advective tendencies of temperature and moisture, large-scale horizontal wind speed, and sea surface temperature for the CRM simulations. Detailed analyses of the satellite cloud object data and the CRM simulations will be performed (1) to evaluate the CRM, with focus on how the microphysics schemes influence the simulated cloud properties and cloud radiative forcing, and (2) to understand the physical mechanisms for the differences among the three regions of east Pacific. A bootstrapping technique will be used to identify the statistical differences between the simulated and observed histograms.

  19. Ionospheric Simulation System for Satellite Observations and Global Assimilative Modeling Experiments (ISOGAME)

    NASA Technical Reports Server (NTRS)

    Pi, Xiaoqing; Mannucci, Anthony J.; Verkhoglyadova, Olga P.; Stephens, Philip; Wilson, Brian D.; Akopian, Vardan; Komjathy, Attila; Lijima, Byron A.

    2013-01-01

    ISOGAME is designed and developed to assess quantitatively the impact of new observation systems on the capability of imaging and modeling the ionosphere. With ISOGAME, one can perform observation system simulation experiments (OSSEs). A typical OSSE using ISOGAME would involve: (1) simulating various ionospheric conditions on global scales; (2) simulating ionospheric measurements made from a constellation of low-Earth-orbiters (LEOs), particularly Global Navigation Satellite System (GNSS) radio occultation data, and from ground-based global GNSS networks; (3) conducting ionospheric data assimilation experiments with the Global Assimilative Ionospheric Model (GAIM); and (4) analyzing modeling results with visualization tools. ISOGAME can provide quantitative assessment of the accuracy of assimilative modeling with the interested observation system. Other observation systems besides those based on GNSS are also possible to analyze. The system is composed of a suite of software that combines the GAIM, including a 4D first-principles ionospheric model and data assimilation modules, an Internal Reference Ionosphere (IRI) model that has been developed by international ionospheric research communities, observation simulator, visualization software, and orbit design, simulation, and optimization software. The core GAIM model used in ISOGAME is based on the GAIM++ code (written in C++) that includes a new high-fidelity geomagnetic field representation (multi-dipole). New visualization tools and analysis algorithms for the OSSEs are now part of ISOGAME.

  20. The Effect of Satellite Observing System Changes on MERRA Water and Energy Fluxes

    NASA Technical Reports Server (NTRS)

    Robertson, Franklin R.; Bosilovich, M. G.; Chen, J.; Miller, T. L.

    2011-01-01

    Because reanalysis data sets offer state variables and fluxes at regular space / time intervals, atmospheric reanalyses have become a mainstay of the climate community for diagnostic purposes and for driving offline ocean and land models. Although one weakness of these data sets is the susceptibility of the flux products to uncertainties because of shortcomings in parameterized model physics, another issue, perhaps less appreciated, is the fact that continual but discreet changes in the evolving observational system, particularly from satellite sensors, may also introduce artifacts in the time series of quantities. In this paper we examine the ability of the NASA MERRA (Modern Era Retrospective Analysis for Research and Applications) and other recent reanalyses to determine variability in the climate system over the satellite record (approx. the last 30 years). In particular we highlight the effect on the reanalysis of discontinuities at the junctures of the onset of passive microwave imaging (Special Sensor Microwave Imager) in late 1987 and, more prominently, with improved sounding and imaging with the Advanced Microwave Sounding Unit, AMSU-A, in 1998. We first examine MERRA fluxes from the perspective of how physical modes of variability (e.g. ENSO events, Pacific Decadal Variability) are contained by artificial step-like trends induced by the onset of new moisture data these two satellite observing systems. Secondly, we show how Redundancy Analysis, a statistical regression methodology, is effective in relating these artifact signals in the moisture and temperature analysis increments to their presence in the physical flux terms (e.g. precipitation, radiation). This procedure is shown to be effective greatly reducing the artificial trends in the flux quantities.

  1. The Effect of Satellite Observing System Changes on MERRA Water and Energy Fluxes

    NASA Technical Reports Server (NTRS)

    Robertson, Franklin R.; Bosilovich, M. G.; Chen, J.; Miller, t. L.

    2010-01-01

    Because reanalysis data sets offer state variables and fluxes at regular space / time intervals, atmospheric reanalyses have become a mainstay of the climate community for diagnostic purposes and for driving offline ocean and land models. Although one weakness of these data sets is the susceptibility of the flux products to uncertainties because of shortcomings in parameterized model physics, another issue, perhaps less appreciated, is the fact that continual but discreet changes in the evolving observational system, particularly from satellite sensors, may also introduce artifacts in the time series of quantities. In this paper we examine the ability of the NASA MERRA (Modern Era Retrospective Analysis for Research and Applications) and other recent reanalyses to determine variability in the climate system over the satellite record (approximately the last 30 years). In particular we highlight the effect on the reanalysis of discontinuities at the junctures of the onset of passive microwave imaging (Special Sensor Microwave Imager) in late 1987 as well as improved sounding and imaging with the Advanced Microwave Sounding Unit, AMSU-A, in 1998. We first examine MERRA fluxes from the perspective of how physical modes of variability (e.g. ENSO events, Pacific Decadal Variability) are contaminated by artificial step-like trends induced by the onset of new moisture data these two satellite observing systems. Secondly, we show how Redundancy Analysis, a statistical regression methodology, is effective in relating these artifact signals in the moisture and temperature analysis increments to their presence in the physical flux terms (e.g. precipitation, radiation). This procedure is shown to be effective greatly reducing the artificial trends in the flux quantities.

  2. A satellite ocean color observation operator system for eutrophication assessment in coastal waters

    NASA Astrophysics Data System (ADS)

    Banks, Andrew Clive; Prunet, Pascal; Chimot, Julien; Pina, Pedro; Donnadille, Jerome; Jeansou, Eric; Lux, Muriel; Petihakis, Giorgos; Korres, Gerasimos; Triantafyllou, Giorgos; Fontana, Clement; Estournel, Claude; Ulses, Caroline; Fernandez, Luis

    2012-06-01

    During the INSEA project the potential positive role that remote sensing products can play in coastal eutrophication assessment systems using assimilation into coupled hydrodynamic-biogeochemical models has been shown. However, products derived from satellite ocean color data continue to suffer from high levels of inaccuracy when compared with in situ measurements of the surface layer of the ocean. This has been particularly pronounced for coastal waters and waters optically classified as Case-II. The early success of using empirical relationships between chlorophyll and simple band ratios to derive estimates of surface layer chlorophyll from the first ocean color satellite sensors' data (i.e. CZCS), has led mainstream ocean color remote sensing and standard ocean color products towards following this approach for subsequent sensors (e.g. SeaWiFS and MODIS). Chlorophyll has continued to be the main focus product but is only related to one of the optical properties of sea water, namely the absorption of light by phytoplankton, whereas empirical band ratio approaches use wavelength banded water leaving radiance resultant from all absorption and scattering of light by all the optically active components of the ocean surface layer. We suggest that using approaches that do not fully exploit remote sensing optical data through a parameterization of the optical properties of sea water, is the main reason for the poor performance of many ocean color products when compared with in situ data. This is in concordance with the International Ocean Color Coordinating Group (IOCCG) and following their recent guidelines, novel inherent optical properties approaches (e.g. for MERIS) and the lines of research that are being used in atmospheric remote sensing, we present a demonstration 'observation operator' system that is based on biogeochemical model output, optical properties (apparent and inherent), and radiative transfer modeling. In the forward mode we demonstrate the system by producing MODIS and SeaWiFS synthetic images of water leaving radiance for the coastal test sites of INSEA. We show that the observation operator approach has the potential to allow the consistent mapping of model variables into observed quantities which simplifies the transport of measurement errors and reduces the need for approximations inherent in previous approaches. In conclusion we discuss the future development and potential of inversion of the system in order to obtain more accurate ocean color biogeochemical products (including chlorophyll) from satellite radiance data for eutrophication assessment. We also highlight the additional advantages there may be for ecological models from having stronger links to bio-optics.

  3. Dynamical and observational constraints on satellites in the inner Pluto-Charon system

    NASA Technical Reports Server (NTRS)

    Stern, S. Alan; Parker, Joel William; Duncan, Martin J.; Snowdall, J. Clark, Jr.; Levison, Harold F.

    1994-01-01

    It is not known if Pluto has other satellites besides its massive partner Charon. In the past, searches for additional satellites in the Pluto-Charon system have extended from the solar-tidal stability boundary (approximately 90 arcsec from Pluto) inward to about 1 arcsec from Pluto. Here we further explore the inner (i.e., less than 10 arcsec) region of the Pluto-Charon system to determine where additional satellites might lie. In particular, we report on (1) dynamical simulations to delineate the region where unstable orbits lie around Charon, (2) dynamical simulations which use the low orbital eccentricity of Charon to constrain the mass of any third body near Pluto, and (3) analysis of Hubble Space Telescope (HST) archival images to search for satellites in the inner Pluto-Charon system. Although no objects were found, significant new constraints on bodies orbiting in the inner Pluto-Charon system were obtained.

  4. A Regional CO2 Observing System Simulation Experiment for the ASCENDS Satellite Mission

    NASA Technical Reports Server (NTRS)

    Wang, J. S.; Kawa, S. R.; Eluszkiewicz, J.; Baker, D. F.; Mountain, M.; Henderson, J.; Nehrkorn, T.; Zaccheo, T. S.

    2014-01-01

    Top-down estimates of the spatiotemporal variations in emissions and uptake of CO2 will benefit from the increasing measurement density brought by recent and future additions to the suite of in situ and remote CO2 measurement platforms. In particular, the planned NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) satellite mission will provide greater coverage in cloudy regions, at high latitudes, and at night than passive satellite systems, as well as high precision and accuracy. In a novel approach to quantifying the ability of satellite column measurements to constrain CO2 fluxes, we use a portable library of footprints (surface influence functions) generated by the WRF-STILT Lagrangian transport model in a regional Bayesian synthesis inversion. The regional Lagrangian framework is well suited to make use of ASCENDS observations to constrain fluxes at high resolution, in this case at 1 degree latitude x 1 degree longitude and weekly for North America. We consider random measurement errors only, modeled as a function of mission and instrument design specifications along with realistic atmospheric and surface conditions. We find that the ASCENDS observations could potentially reduce flux uncertainties substantially at biome and finer scales. At the 1 degree x 1 degree, weekly scale, the largest uncertainty reductions, on the order of 50 percent, occur where and when there is good coverage by observations with low measurement errors and the a priori uncertainties are large. Uncertainty reductions are smaller for a 1.57 micron candidate wavelength than for a 2.05 micron wavelength, and are smaller for the higher of the two measurement error levels that we consider (1.0 ppm vs. 0.5 ppm clear-sky error at Railroad Valley, Nevada). Uncertainty reductions at the annual, biome scale range from 40 percent to 75 percent across our four instrument design cases, and from 65 percent to 85 percent for the continent as a whole. Our uncertainty reductions at various scales are substantially smaller than those from a global ASCENDS inversion on a coarser grid, demonstrating how quantitative results can depend on inversion methodology. The a posteriori flux uncertainties we obtain, ranging from 0.01 to 0.06 Pg C yr-1 across the biomes, would meet requirements for improved understanding of long-term carbon sinks suggested by a previous study.

  5. A regional CO2 observing system simulation experiment for the ASCENDS satellite mission

    NASA Astrophysics Data System (ADS)

    Wang, J. S.; Kawa, S. R.; Eluszkiewicz, J.; Baker, D. F.; Mountain, M.; Henderson, J.; Nehrkorn, T.; Zaccheo, T. S.

    2014-12-01

    Top-down estimates of the spatiotemporal variations in emissions and uptake of CO2 will benefit from the increasing measurement density brought by recent and future additions to the suite of in situ and remote CO2 measurement platforms. In particular, the planned NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) satellite mission will provide greater coverage in cloudy regions, at high latitudes, and at night than passive satellite systems, as well as high precision and accuracy. In a novel approach to quantifying the ability of satellite column measurements to constrain CO2 fluxes, we use a portable library of footprints (surface influence functions) generated by the Stochastic Time-Inverted Lagrangian Transport (STILT) model in combination with the Weather Research and Forecasting (WRF) model in a regional Bayesian synthesis inversion. The regional Lagrangian particle dispersion model framework is well suited to make use of ASCENDS observations to constrain weekly fluxes in North America at a high resolution, in this case at 1° latitude × 1° longitude. We consider random measurement errors only, modeled as a function of the mission and instrument design specifications along with realistic atmospheric and surface conditions. We find that the ASCENDS observations could potentially reduce flux uncertainties substantially at biome and finer scales. At the grid scale and weekly resolution, the largest uncertainty reductions, on the order of 50%, occur where and when there is good coverage by observations with low measurement errors and the a priori uncertainties are large. Uncertainty reductions are smaller for a 1.57 ?m candidate wavelength than for a 2.05 ?m wavelength, and are smaller for the higher of the two measurement error levels that we consider (1.0 ppm vs. 0.5 ppm clear-sky error at Railroad Valley, Nevada). Uncertainty reductions at the annual biome scale range from ~40% to ~75% across our four instrument design cases and from ~65% to ~85% for the continent as a whole. Tests suggest that the quantitative results are moderately sensitive to assumptions regarding a priori uncertainties and boundary conditions. The a posteriori flux uncertainties we obtain, ranging from 0.01 to 0.06 Pg C yr-1 across the biomes, would meet requirements for improved understanding of long-term carbon sinks suggested by a previous study.

  6. A regional CO2 observing system simulation experiment for the ASCENDS Satellite Mission

    NASA Astrophysics Data System (ADS)

    Wang, J. S.; Kawa, S. R.; Eluszkiewicz, J.; Baker, D. F.; Mountain, M.; Henderson, J.; Nehrkorn, T.; Zaccheo, T. S.

    2014-05-01

    Top-down estimates of the spatiotemporal variations in emissions and uptake of CO2 will benefit from the increasing measurement density brought by recent and future additions to the suite of in situ and remote CO2 measurement platforms. In particular, the planned NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) satellite mission will provide greater coverage in cloudy regions, at high latitudes, and at night than passive satellite systems, as well as high precision and accuracy. In a novel approach to quantifying the ability of satellite column measurements to constrain CO2 fluxes, we use a portable library of footprints (surface influence functions) generated by the WRF-STILT Lagrangian transport model in a regional Bayesian synthesis inversion. The regional Lagrangian framework is well suited to make use of ASCENDS observations to constrain fluxes at high resolution, in this case at 1° latitude × 1° longitude and weekly for North America. We consider random measurement errors only, modeled as a function of mission and instrument design specifications along with realistic atmospheric and surface conditions. We find that the ASCENDS observations could potentially reduce flux uncertainties substantially at biome and finer scales. At the 1° × 1°, weekly scale, the largest uncertainty reductions, on the order of 50%, occur where and when there is good coverage by observations with low measurement errors and the a priori uncertainties are large. Uncertainty reductions are smaller for a 1.57 ?m candidate wavelength than for a 2.05 ?m wavelength, and are smaller for the higher of the two measurement error levels that we consider (1.0 ppm vs. 0.5 ppm clear-sky error at Railroad Valley, Nevada). Uncertainty reductions at the annual, biome scale range from ∼40% to ∼75% across our four instrument design cases, and from ∼65% to ∼85% for the continent as a whole. Our uncertainty reductions at various scales are substantially smaller than those from a global ASCENDS inversion on a coarser grid, demonstrating how quantitative results can depend on inversion methodology. The a posteriori flux uncertainties we obtain, ranging from 0.01 to 0.06 Pg C yr-1 across the biomes, would meet requirements for improved understanding of long-term carbon sinks suggested by a previous study.

  7. Preliminary design of a satellite observation system for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Cabe, Greg (editor); Gallagher, Chris; Wilson, Brian; Rehfeld, James; Maurer, Alexa; Stern, Dan; Nualart, Jaime; Le, Xuan-Trang

    1992-01-01

    Degobah Satellite Systems (DSS), in cooperation with the University Space Research Association (USRA), NASA - Johnson Space Center (JSC), and the University of Texas, has completed the preliminary design of a satellite system to provide inexpensive on-demand video images of all or any portion of Space Station Freedom (SSF). DSS has narrowed the scope of the project to complement the work done by Mr. Dennis Wells at Johnson Space Center. This three month project has resulted in completion of the preliminary design of AERCAM, the Autonomous Extravehicular Robotic Camera, detailed in this design report. This report begins by providing information on the project background, describing the mission objectives, constraints, and assumptions. Preliminary designs for the primary concept and satellite subsystems are then discussed in detail. Included in the technical portion of the report are detailed descriptions of an advanced imaging system and docking and safing systems that ensure compatibility with the SSF. The report concludes by describing management procedures and project costs.

  8. The Earth Observing System Microwave Limb Sounder (EOS MLS) on the Aura Satellite

    NASA Technical Reports Server (NTRS)

    Waters, Joe W.; Froidevaux, Lucien; Harwood, Robert S.; Jarnot, Robert F.; Pickett, Herbert M.; Read, William G.; Siegel, Peter H.; Cofield, Richard E.; Filipiak, Mark J.; Flower, Dennis A.; Holden, James R.; Lau, Gary K.; Livesey, Nathaniel J.; Manney, Gloria L; Pumphrey, Hugh C.; Santee, Michelle L.; Wu, Dong L.; Cuddy, David T.; Lay, Richard R.; Loo, Mario S.; Perun, Vincent S.; Schwartz, Michael J.; Stek, Paul C.; Thurstans, Robert P.; Boyles, Mark A.

    2006-01-01

    The Earth Observing System Microwave Limb Sounder measures several atmospheric chemical species (OH, HO2, H2O, O3, HCl, ClO, HOCl, BrO, HNO3, N2O, CO, HCN, CH3CN, volcanic SO2), cloud ice, temperature, and geopotential height to improve our understanding of stratospheric ozone chemistry, the interaction of composition and climate, and pollution in the upper troposphere. All measurements are made simultaneously and continuously, during both day and night. The instrument uses heterodyne radiometers that observe thermal emission from the atmospheric limb in broad spectral regions centered near 118, 190, 240, and 640 GHz, and 2.5 THz. It was launched July 15, 2004 on the National Aeronautics and Space Administration's Aura satellite and started full-up science operations on August 13, 2004. An atmospheric limb scan and radiometric calibration for all bands are performed routinely every 25 s. Vertical profiles are retrieved every 165 km along the suborbital track, covering 82 S to 82 N latitudes on each orbit. Instrument performance to date has been excellent; data have been made publicly available; and initial science results have been obtained.

  9. Evaluation of the model representation of the evolution of convective systems using satellite observations of outgoing

    E-print Network

    Allan, Richard P.

    Evaluation of the model representation of the evolution of convective systems using satellite. Hogan, R. P. Allan, G. M. S. Lister, and C. E. Holloway (2010), Evaluation of the model representation to output from the Met Office Unified Model run at two resolutions. The 12 km resolution model produces peak

  10. Operational Applications of Satellite Snowcover Observations

    NASA Technical Reports Server (NTRS)

    Rango, A. (editor); Peterson, R. (editor)

    1980-01-01

    The history of remote sensing of snow cover is reviewed and the following topics are covered: various techniques for interpreting LANDSAT and NOAA satellite data; the status of future systems for continuing snow hydrology applications; the use of snow cover observations in streamflow forecasts by Applications Systems Verification and Transfer participants and selected foreign investigators; and the benefits of using satellite snow cover data in runoff prediction.

  11. Assessing the Impact of Advanced Satellite Observations in the NASA GEOS-5 Forecast System Using the Adjoint Method

    NASA Technical Reports Server (NTRS)

    Gelaro, Ron; Liu, Emily; Sienkiewicz, Meta

    2011-01-01

    The adjoint of a data assimilation system provides a flexible and efficient tool for estimating observation impacts on short-range weather forecasts. The impacts of any or all observations can be estimated simultaneously based on a single execution of the adjoint system. The results can be easily aggregated according to data type, location, channel, etc., making this technique especially attractive for examining the impacts of new hyper-spectral satellite instruments and for conducting regular, even near-real time, monitoring of the entire observing system. In this talk, we present results from the adjoint-based observation impact monitoring tool in NASA's GEOS-5 global atmospheric data assimilation and forecast system. The tool has been running in various off-line configurations for some time, and is scheduled to run as a regular part of the real-time forecast suite beginning in autumn 20 I O. We focus on the impacts of the newest components of the satellite observing system, including AIRS, IASI and GPS. For AIRS and IASI, it is shown that the vast majority of the channels assimilated have systematic positive impacts (of varying magnitudes), although some channels degrade the forecast. Of the latter, most are moisture-sensitive or near-surface channels. The impact of GPS observations in the southern hemisphere is found to be a considerable overall benefit to the system. In addition, the spatial variability of observation impacts reveals coherent patterns of positive and negative impacts that may point to deficiencies in the use of certain observations over, for example, specific surface types. When performed in conjunction with selected observing system experiments (OSEs), the adjoint results reveal both redundancies and dependencies between observing system impacts as observations are added or removed from the assimilation system. Understanding these dependencies appears to pose a major challenge for optimizing the use of the current observational network and defining requirements for future observing systems.

  12. Ocean observer study: A proposed national asset to augment the future U.S. operational satellite system

    USGS Publications Warehouse

    Cunningham, J.D.; Chambers, D.; Davis, C.O.; Gerber, A.; Helz, R.; McGuire, J.P.; Pichel, W.

    2003-01-01

    The next generation of U.S. polar orbiting environmental satellites, are now under development. These satellites, jointly developed by the Department of Defense (DoD), the Department of Commerce (DOC), and the National Aeronautics and Space Administration (NASA), will be known as the National Polar-orbiting Operational Environmental Satellite System (NPOESS). It is expected that the first of these satellites will be launched in 2010. NPOESS has been designed to meet the operational needs of the U.S. civilian meteorological, environmental, climatic, and space environmental remote sensing programs, and the Global Military Space and Geophysical Environmental remote sewing programs. This system, however, did not meet all the needs of the user community interested in operational oceanography (particularly in coastal regions). Beginning in the fall of 2000, the Integrated Program Office (IPO), a joint DoD, DOC, and NASA office responsible for the NPOESS development, initiated the Ocean Observer Study (OOS). The purpose of this study was to assess and recommend how best to measure the missing or inadequately sampled ocean parameters. This paper summarizes the ocean measurement requirements documented in the OOS, describes the national need to measure these parameters, and describes the satellite instrumentation required to make those measurements.

  13. Satellite services system overview

    NASA Technical Reports Server (NTRS)

    Rysavy, G.

    1982-01-01

    The benefits of a satellite services system and the basic needs of the Space Transportation System to have improved satellite service capability are identified. Specific required servicing equipment are discussed in terms of their technology development status and their operative functions. Concepts include maneuverable television systems, extravehicular maneuvering unit, orbiter exterior lighting, satellite holding and positioning aid, fluid transfer equipment, end effectors for the remote manipulator system, teleoperator maneuvering system, and hand and power tools.

  14. Geopotential Error Analysis from Satellite Gradiometer and Global Positioning System Observables on Parallel Architecture

    NASA Technical Reports Server (NTRS)

    Schutz, Bob E.; Baker, Gregory A.

    1997-01-01

    The recovery of a high resolution geopotential from satellite gradiometer observations motivates the examination of high performance computational techniques. The primary subject matter addresses specifically the use of satellite gradiometer and GPS observations to form and invert the normal matrix associated with a large degree and order geopotential solution. Memory resident and out-of-core parallel linear algebra techniques along with data parallel batch algorithms form the foundation of the least squares application structure. A secondary topic includes the adoption of object oriented programming techniques to enhance modularity and reusability of code. Applications implementing the parallel and object oriented methods successfully calculate the degree variance for a degree and order 110 geopotential solution on 32 processors of the Cray T3E. The memory resident gradiometer application exhibits an overall application performance of 5.4 Gflops, and the out-of-core linear solver exhibits an overall performance of 2.4 Gflops. The combination solution derived from a sun synchronous gradiometer orbit produce average geoid height variances of 17 millimeters.

  15. Full time and full coverage global observation system for ecological monitoring base on MEO satellite grid constellation

    NASA Astrophysics Data System (ADS)

    You, Rui; Liu, Shuhao

    Human life more and more rely on earth environment and atmosphere, environmental information required by space based monitor is a crucial importance, although GEO and polar weather satellite in orbit by several countries, but it can’t monitor all zone of earth with real time. This paper present a conception proposal which can realize stable, continue and real time observation for any zone(include arctic and ant-arctic zone) of earth and its atmosphere, it base on walker constellation in 20000Km high medium orbit with 24 satellites, payloads configuration with infrared spectrometer, visible camera, ultraviolet ray camera, millimeter wave radiometer, leaser radar, spatial resolution are 1km@ infrared,0.5km@ visible optical. This satellite of grid constellation can monitor any zone of global with 1-3hours retrial observation cycles. Air pollution, ozone of atmosphere, earth surface pollution, desert storm, water pollution, vegetation change, natural disasters, man-made emergency situations, agriculture and climate change can monitor by this MEO satellite grid constellation. This system is a international space infrastructure, use of mature technologies and products, can build by co-operation with multi countries.

  16. Satellite observed thermodynamics during FGGE

    NASA Technical Reports Server (NTRS)

    Smith, W. L.

    1985-01-01

    During the First Global Atmospheric Research Program (GARP) Global Experiment (FGGE), determinations of temperature and moisture were made from TIROS-N and NOAA-6 satellite infrared and microwave sounding radiance measurements. The data were processed by two methods differing principally in their horizontal resolution. At the National Earth Satellite Service (NESS) in Washington, D.C., the data were produced operationally with a horizontal resolution of 250 km for inclusion in the FGGE Level IIb data sets for application to large-scale numerical analysis and prediction models. High horizontal resolution (75 km) sounding data sets were produced using man-machine interactive methods for the special observing periods of FGGE at the NASA/Goddard Space Flight Center and archived as supplementary Level IIb. The procedures used for sounding retrieval and the characteristics and quality of these thermodynamic observations are given.

  17. Providing access to satellite imagery through OGC catalog service interfaces in support of the Global Earth Observation System of Systems

    NASA Astrophysics Data System (ADS)

    Bai, Yuqi; Di, Liping

    2011-04-01

    The Global Earth Observation System of Systems (GEOSS) architecture requires supporting discovery and access to large volumes of Earth Observation data. To support this application requirement in a polar ecosystem scenario, the project constructed a metadata catalog service for pre-collected orthorectified Landsat satellite images with global coverage. This study investigates the characteristics and challenges in building Open Geospatial Consortium Inc. (OGC) catalog service. It further presents a general lightweight XML adapter for relational tables, followed by a general OGC catalog service solution based on this adapter. This adapter relies on two configuration files to make the core software modules independent of the underlying metadata database structure. One configuration file identifies how XML schema is mapped into relational schema, and the other represents the XML output template. At runtime, this adapter internally employs a two-step mechanism: XQuery processing and XML publication. In the XQuery processing step, metadata discovery requests are interpreted, resulting in an SQL query clause. In the XML publication step, this SQL query and other dynamically generated queries are executed to generate the output according to the predefined XML template. Successful application of this OGC catalog service solution in the GEOSS AIP-2 polar ecosystem scenario is presented, followed by an analysis on its advantages and limitations.

  18. A comparison of mapped and measured total ionospheric electron content using global positioning system and beacon satellite observations

    NASA Technical Reports Server (NTRS)

    Lanyi, Gabor E.; Roth, Titus

    1988-01-01

    Total ionospheric electron contents (TEC) were measured by global positioning system (GPS) dual-frequency receivers developed by the Jet Propulsion Laboratory. The measurements included P-code (precise ranging code) and carrier phase data for six GPS satellites during multiple five-hour observing sessions. A set of these GPS TEC measurements were mapped from the GPS lines of sight to the line of sight of a Faraday beacon satellite by statistically fitting the TEC data to a simple model of the ionosphere. The mapped GPS TEC values were compared with the Faraday rotation measurements. Because GPS transmitter offsets are different for each satellite and because some GPS receiver offsets were uncalibrated, the sums of the satellite and receiver offsets were estimated simultaneously with the TEC in a least squares procedure. The accuracy of this estimation procedure is evaluated indicating that the error of the GPS-determined line of sight TEC can be at or below 1 x 10 to the 16th el/sq cm. Consequently, the current level of accuracy is comparable to the Faraday rotation technique; however, GPS provides superior sky coverage.

  19. Satellite irrigation management support with the terrestrial observation and prediction system: A framework for integration of satellite & surface observations to support improvements in agricultural water resource management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In California and other regions vulnerable to water shortages, satellite-derived estimates of key hydrologic parameters can support agricultural producers and water managers in maximizing the benefits of available water supplies. The Satellite Irrigation Management Support (SIMS) project combines N...

  20. The atmospheric composition geostationary satellite constellation for air quality and climate science: Evaluating performance with Observation System Simulation Experiments

    NASA Astrophysics Data System (ADS)

    Edwards, D. P.; Barre, J.; Worden, H. M.; Arellano, A. F.; Gaubert, B.; Anderson, J. L.; Mizzi, A. P.; Lahoz, W. A.

    2014-12-01

    Current satellite observations of tropospheric composition made from low Earth orbit provide at best one or two measurements each day at any given location. Coverage is global but sparse, often with large uncertainties in individual measurements that limit examination of local and regional atmospheric composition over short time periods. This has hindered the operational uptake of these data for monitoring air quality and population exposure, and for initializing and evaluating chemical weather forecasts. By the end of the current decade there are planned geostationary Earth orbit (GEO) satellite missions for atmospheric composition over North America, East Asia and Europe with additional missions proposed. Together, these present the possibility of a constellation of GEO platforms to achieve continuous time-resolved high-density observations of continental domains for mapping pollutant sources and variability on diurnal and local scales. We describe Observing System Simulation Experiments (OSSEs) to evaluate the contributions of these GEO missions to improve knowledge of near-surface air pollution due to intercontinental long-range transport and quantify chemical precursor emissions. We discuss the requirements on measurement simulation, chemical transport modeling, and data assimilation for a successful OSSE infrastructure. Our approach uses an efficient computational method to sample a high-resolution global GEOS-5 chemistry Nature Run over each geographical region of the GEO constellation. The demonstration carbon monoxide (CO) observation simulator, which is being expanded to other chemical pollutants, currently produces multispectral retrievals and captures realistic scene-dependent variation in measurement vertical sensitivity and cloud cover. We use the DART Ensemble Adjustment Kalman Filter to assimilate the simulated observations in a CAM-Chem global chemistry-climate model Control Run. The impact of observing over each region is evaluated using data denial experiments. Finally, we report on international collaborations using the OSSE approach to determine expected performance of planned satellite systems and set requirements for future missions.

  1. Satellite Antenna Systems

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Through the Technology Affiliates Program at the Jet Propulsion Laboratory, the ACTS antenna system was transferred from experimental testing status to commercial development with KVH Industries, Inc. The ACTS design enables mobile satellite antennas to remain pointed at the satellite, regardless of the motion or vibration on which it is mounted. KVH's first product based on the ACTS design is a land-mobile satellite antenna system that will enable direct broadcast satellite television aboard moving trucks, recreational vehicles, trains, and buses. Future products could include use in broadcasting, emergency medical and military vehicles.

  2. The Earth Observing System. [instrument investigations for flight on EOS-A satellite

    NASA Technical Reports Server (NTRS)

    Wilson, Stan; Dozier, Jeff

    1991-01-01

    The Earth Observing System (EOS), the centerpiece of NASA's Mission to Planet Earth, is to study the interactions of the atmosphere, land, oceans, and living organisms, using the perspective of space to observe the earth as a global environmental system. To better understand the role of clouds in global change, EOS will measure incoming and emitted radiation at the top of the atmosphere. Then, to study characteristics of the atmosphere that influence radiation transfer between the top of the atmosphere and the surface, EOS wil observe clouds, water vapor and cloud water, aerosols, temperature and humidity, and directional effects. To elucidate the role of anthropogenic greenhouse gas and terrestrial and marine plants as a source or sink for carbon, EOS will observe the biological productivity of lands and oceans. EOS will also study surface properties that affect biological productivity at high resolution spatially and spectrally.

  3. Measurements of Tropospheric NO2 in Romania Using a Zenith-Sky Mobile DOAS System and Comparisons with Satellite Observations

    PubMed Central

    Constantin, Daniel-Eduard; Merlaud, Alexis; Van Roozendael, Michel; Voiculescu, Mirela; Fayt, Caroline; Hendrick, François; Pinardi, Gaia; Georgescu, Lucian

    2013-01-01

    In this paper we present a new method for retrieving tropospheric NO2 Vertical Column Density (VCD) from zenith-sky Differential Optical Absorption Spectroscopy (DOAS) measurements using mobile observations. This method was used during three days in the summer of 2011 in Romania, being to our knowledge the first mobile DOAS measurements peformed in this country. The measurements were carried out over large and different areas using a mobile DOAS system installed in a car. We present here a step-by-step retrieval of tropospheric VCD using complementary observations from ground and space which take into account the stratospheric contribution, which is a step forward compared to other similar studies. The detailed error budget indicates that the typical uncertainty on the retrieved NO2tropospheric VCD is less than 25%. The resulting ground-based data set is compared to satellite measurements from the Ozone Monitoring Instrument (OMI) and the Global Ozone Monitoring Experiment-2 (GOME-2). For instance, on 18 July 2011, in an industrial area located at 47.03°N, 22.45°E, GOME-2 observes a tropospheric VCD value of (3.4 ± 1.9) × 1015 molec./cm2, while average mobile measurements in the same area give a value of (3.4 ± 0.7) × 1015 molec./cm2. On 22 August 2011, around Ploiesti city (44.99°N, 26.1°E), the tropospheric VCD observed by satellites is (3.3 ± 1.9) × 1015 molec./cm2 (GOME-2) and (3.2 ± 3.2) × 1015 molec./cm2 (OMI), while average mobile measurements give (3.8 ± 0.8) × 1015 molec./cm2. Average ground measurements over “clean areas”, on 18 July 2011, give (2.5 ± 0.6) × 1015 molec./cm2 while the satellite observes a value of (1.8 ± 1.3) × 1015 molec./cm2. PMID:23519349

  4. Voyager 2 radio science observations of the uranian system: atmosphere, rings, and satellites.

    PubMed

    Tyler, G L; Sweetnam, D N; Anderson, J D; Campbell, J K; Eshleman, V R; Hinson, D P; Levy, G S; Lindal, G F; Marouf, E A; Simpson, R A

    1986-07-01

    Voyager 2 radio occultation measurements of the Uranian atmosphere were obtained between 2 and 7 degrees south latitude. Initial atmospheric temperature profiles extend from pressures of 10 to 900 millibars over a height range of about 100 kilometers. Comparison of radio and infrared results yields mole fractions near the tropopause of 0.85 and 0.15 +/- 0.05 for molecular hydrogen and helium, respectively, if no other components are present; for this composition the tropopause is at about 52 kelvins and 110 millibars. Distinctive features in the signal intensity measurements for pressures above 900 millibars strongly favor model atmospheres that include a cloud deck of methane ice. Modeling of the intensity measurements for the cloud region and below indicates that the cloud base is near 1,300 millibars and 81 kelvins and yields an initial methane mole fraction of about 0.02 for the deep atmosphere. Scintillations in signal intensity indicate small-scale stucture throughout the stratosphere and upper troposphere. As judged from data obtained during occultation ingress, the ionosphere consists of a multilayer structure that includes two distinct layers at 2,000 and 3,500 kilometers above the 100-millibar level and an extended topside that may reach altitudes of 10,000 kilometers or more. Occultation measurements of the nine previously known rings at wavelengths of 3.6 and 13 centimeters show characteristic values of optical depth between about 0.8 and 8; the maxim value occurs in the outer region of the in ring, near its periapsis. Forward-scattered signals from this ring have properties that differ from those of any of Saturn's rings, and they are inconsistent with a discrete scattering object or local (three-dimensional) assemblies of orbiting objects. These signals suggest a new kdnd of planetary ring feature characterized by highly ordered cylindrical substructures of radial scale on the order of meters and azimuthal scale of kilometers or more. From radio data alone the mass of the Uranian system is GM(sys) = 5,794,547- 60 cubic kilometers per square second; from a combination of radio and optical navigation data the mass of Uranus alone is GM(u) = 5,793,939+/- 60 cubic kilometers per square second. From all available Voyager data, induding imaging radii, the mean uncompressed density of the five major satellites is 1.40+/- 0.07 grams per cubic centimeter; this value is consistent with a solar mix of material and apparently rules out a cometary origin of the satellites. PMID:17812893

  5. Earth resources satellite systems for flood monitoring

    NASA Technical Reports Server (NTRS)

    Mcginnis, D. F.; Rango, A.

    1975-01-01

    The environmental satellites NOAA-2 and ERTS-1 observed flooding in United States' rivers such as the Mississippi during 1973. Combination of NOAA-2 observation frequency and the ERTS-1 resolution provides an adequate satellite system for monitoring floods. Several polar-orbiting satellites of the ERTS type could view flooded areas at a reasonably high resolution every three to five days. A high-resolution earth-synchronous satellite would further enhance flood mapping by providing observations whenever clouds are absent.

  6. Flow-topography interactions in the northern California Current System observed from geostationary satellite data

    E-print Network

    Balasubramanian, Ravi

    Flow-topography interactions in the northern California Current System observed from geostationary: Castelao, R. M., J. A. Barth, and T. P. Mavor (2005), Flow-topography interactions in the northern in regions of simple topography, to the north of Newport (44.65°N). Recently, however, interest in regions

  7. Jupiter System Observer

    NASA Technical Reports Server (NTRS)

    Senske, Dave; Kwok, Johnny

    2008-01-01

    This slide presentation reviews the proposed mission for the Jupiter System Observer. The presentation also includes overviews of the mission timeline, science goals, and spacecraftspecifications for the satellite.

  8. The National Polar-orbiting Operational Environmental Satellite System: Capabilities for Atmospheric Remote Sensing for NWP and Climate -- Moving Towards a Global Earth Observation System of Systems

    NASA Astrophysics Data System (ADS)

    Mango, S. A.; Hinnant, F.; Hoffman, C. W.; Smehil, D. L.; Schneider, S. R.; Simione, S.; Needham, B.; Stockton, D.

    2005-12-01

    Over the last decade, the tri-agency Integrated Program Office (IPO), comprised of the National Oceanic and Atmospheric Administration (NOAA), the Department of Defense (DoD), and the National Aeronautics and Space Administration (NASA), has been managing the development of the National Polar-orbiting Operational Environmental Satellite System (NPOESS). Once operational later this decade, NPOESS will replace NOAA's Polar-orbiting Operational Environmental Satellites (POES) and DoD's Defense Meteorological Satellite Program (DMSP) systems. The IPO, through its Acquisition and Operations contractor, Northrop Grumman, will launch NPOESS spacecraft into three orbital planes to provide a single, national system capable of satisfying both civil and national security requirements for space-based, remotely sensed environmental data. With the development of NPOESS, we are evolving the existing "weather" satellites into integrated environmental observing systems by expanding our capabilities to observe, assess, and predict the total Earth system - ocean, atmosphere, land, and the space environment. The NPOESS will enable more accurate short-term weather forecasts and severe storm warnings and improved monitoring of atmospheric phenomena. NPOESS will also provide continuity of critical data for monitoring, understanding, and predicting climate change and assessing the impacts of climate change on seasonal and longer time scales. For these purposes, the NPOESS Integrated Program Office [IPO] is developing a suite of advanced, atmospheric sounding/probing instruments as a major part of the next generation meteorological, environmental and climate operational satellite system in polar, low earth orbit [LEO]. The IPO is developing the CrIS, Cross-track Infrared Sounder, an Ozone Mapping & Profiler Suite [OMPS]and a Visible and Infrared Imager and Radiometer Suite [VIIRS] and NASA is developing an Advanced Technology Microwave Sounder [ATMS]. These four instruments will be key parts of the NPOESS operational satellite system and its precursor, bridging and risk-reduction mission - the NPOESS Preparatory Project [NPP]. The CrIS/ATMS/OMPS (& VIIRS) and, later on NPOESS, a Conical-scanning Microwave Imager and Sounder [CMIS] will represent a USA highly capable, complementary sounding and imaging suite for the next generation. In the same time frame the European community, EUMETSAT, European Organization for the Exploitation of Meteorological Satellite Systems, will be flying their next generation, operational, polar-orbiting LEO system, METOP. METOP will have a highly capable FTS sounder, IASI [Infrared Atmospheric Sounder Interferometer], an Advanced Microwave Sounding Unit [AMSU], a Global Ozone Monitoring Experiment [GOME-2], a GNSS Receiver for Atmospheric Sounding [GRAS]and an Advanced Very High Resolution Radiometer [AVHRR]. The NPOESS & METOP sounders and imagers will represent a significant contribution to a polar-orbiting, atmospheric sounding and imaging component of an emerging Global Earth Observation System of Systems [GEOSS] for NWP and Climate. Similarly the Geostationary Operational Environmental Satellite System [GOES-R] & Meteosat Second Generation [MSG] sounders and imagers will represent an important geostationary component of such a GEOSS.

  9. Satellite Observations of Tropospheric Ammonia

    NASA Astrophysics Data System (ADS)

    Shephard, M. W.; Luo, M.; Rinsland, C. P.; Cady-Pereira, K. E.; Beer, R.; Pinder, R. W.; Henze, D.; Payne, V. H.; Clough, S.; Rodgers, C. D.; Osterman, G. B.; Bowman, K. W.; Worden, H. M.

    2008-12-01

    Global high-spectral resolution (0.06 cm-1) nadir measurements from TES-Aura enable the simultaneous retrieval of a number of tropospheric pollutants and trace gases in addition to the TES standard operationally retrieved products (e.g. carbon monoxide, ozone). Ammonia (NH3) is one of the additional species that can be retrieved in conjunction with the TES standard products, and is important for local, regional, and global tropospheric chemistry studies. Ammonia emissions contribute significantly to several well-known environmental problems, yet the magnitude and seasonal/spatial variability of the emissions are poorly constrained. In the atmosphere, an important fraction of fine particulate matter is composed of ammonium nitrate and ammonium sulfate. These particles are statistically associated with health impacts. When deposited to ecosystems in excess, nitrogen, including ammonia can cause nutrient imbalances, change in ecosystem species composition, eutrophication, algal blooms and hypoxia. Ammonia is also challenging to measure in-situ. Observations of surface concentrations are rare and are particularly sparse in North America. Satellite observations of ammonia are therefore highly desirable. We recently demonstrated that tropospheric ammonia is detectable in the TES spectra and presented some corresponding preliminary retrievals over a very limited range of conditions (Beer et al., 2008). Presented here are results that expand upon these initial TES ammonia retrievals in order to evaluate/validate the retrieval results utilizing in-situ surface observations (e.g. LADCO, CASTNet, EPA /NC State) and chemical models (e.g. GEOS-Chem and CMAQ). We also present retrievals over regions of interest that have the potential to help further understand air quality and the active nitrogen cycle. Beer, R., M. W. Shephard, S. S. Kulawik, S. A. Clough, A. Eldering, K. W. Bowman, S. P. Sander, B. M. Fisher, V. H. Payne, M. Luo, G. B. Osterman, and J. R. Worden, First satellite observations of lower tropospheric ammonia and methanol, Geophysical Res. Letters, 35, L09801, doi:10.1029/2008GL033642, 2008.

  10. Applications systems verification and transfer project. Volume 1: Operational applications of satellite snow cover observations: Executive summary. [usefulness of satellite snow-cover data for water yield prediction

    NASA Technical Reports Server (NTRS)

    Rango, A.

    1981-01-01

    Both LANDSAT and NOAA satellite data were used in improving snowmelt runoff forecasts. When the satellite snow cover data were tested in both empirical seasonal runoff estimation and short term modeling approaches, a definite potential for reducing forecast error was evident. A cost benefit analysis run in conjunction with the snow mapping indicated a $36.5 million annual benefit accruing from a one percent improvement in forecast accuracy using the snow cover data for the western United States. The annual cost of employing the system would be $505,000. The snow mapping has proven that satellite snow cover data can be used to reduce snowmelt runoff forecast error in a cost effective manner once all operational satellite data are available within 72 hours after acquisition. Executive summaries of the individual snow mapping projects are presented.

  11. Assessment of errors in Precipitable Water data derived from Global Navigation Satellite System observations

    NASA Astrophysics Data System (ADS)

    Hordyniec, Pawel; Bosy, Jaroslaw; Rohm, Witold

    2015-07-01

    Among the new remote sensing techniques, one of the most promising is a GNSS meteorology, which provides continuous remote monitoring of the troposphere water vapor in all weather conditions with high temporal and spatial resolution. The Continuously Operating Reference Station (CORS) network and available meteorological instrumentation and models were scrutinized (we based our analysis on ASG-EUPOS network in Poland) as a troposphere water vapor retrieval system. This paper shows rigorous mathematical derivation of Precipitable Water errors based on uncertainties propagation method using all available data source quality measures (meteorological sensors and models precisions, ZTD estimation error, interpolation discrepancies, and ZWD to PW conversion inaccuracies). We analyze both random and systematic errors introduced by indirect measurements and interpolation procedures, hence estimate the PW system integrity capabilities. The results for PW show that the systematic errors can be under half-millimeter level as long as pressure and temperature are measured at the observation site. In other case, i.e. no direct observations, numerical weather model fields (we used in this study Coupled Ocean Atmospheric Mesoscale Prediction System) serves as the most accurate source of data. Investigated empirical pressure and temperature models, such as GPT2, GPT, UNB3m and Berg introduced into WV retrieval system, combined bias and random errors exceeding PW standard level of accuracy (3 mm according to E-GVAP report). We also found that the pressure interpolation procedure is introducing over 0.5 hPa bias and 1 hPa standard deviation into the system (important in Zenith Total Delay reduction) and hence has negative impact on the WV estimation quality.

  12. A regional GSI-based EnKF system for the Rapid Refresh configuration: Tests for Satellite Radiance Observation

    NASA Astrophysics Data System (ADS)

    Zhu, Kefeng; Xue, Ming

    2015-04-01

    A regional ensemble Kalman filter data assimilation (EnKF) system based on the NCEP operational Grid-point Statistical Interpolation (GSI) system has been established for the target Rapid Refresh (RAP) applications. The EnKF system borrows the data processing and observation operators from the GSI system, and pre-calculates observation priors using the GSI. The filter is based on the serial ensemble square-root Kalman filter (EnSRF) and updates both the state vector and observation priors and its distributed memory parallelization is carried out at the state vector level. In this study, the impact of satellite radiance including AMSU, AIRS, MHS and HIRS within the established EnKF-RAP framework was examined. Testing is performed at the ~40 km grid spacing, and its performance is compared to the GSI system which uses three dimensional variation method. The performance is evaluated in terms of short-range (up to 18 hours) forecast errors verified again soundings. The assimilation of AMSU-A data improved the forecast accuracy for all the verified variables especially for the wind components; the assimilation of AIRS data greatly improved the forecast accuracy of relative humidity; when all the radiance data were assimilated, the forecast is the best. The forecast started from EnKF analysis is consistently better than from GSI analysis though the relative improvement is smaller than GSI. In additional, the configurations like bias correction and thinning for radiance assimilation within ENKF-RAP will be presented and discussed.

  13. Fault Tolerant Design for Attitude Orbit Control System (AOCS) of ADEOS-II (Advanced Earth Observing Satellite-II)

    NASA Astrophysics Data System (ADS)

    Kojima, Yasushi; Tanamachi, Takehiko; Ohkami, Yoshiaki

    Fault tolerance of Spacecraft Attitude and Control Subsystem (AOCS) is extremely important because an AOCS failure can result in the total loss of spacecraft. More specifically, FDIR (Fault Detection, Isolation and Recovery) function has been applied to many satellites resulting in successful mission operations. This paper presents the FDIR function for the AOCS of ADEOS-II with emphasis on a newly developed FDIR for hybrid navigation. Hybrid navigation which is ADEOS-II nominal operational mode processes GPS Receiver (GPSR), Fine Sun Sensor Head (FSSH), Inertial Reference Unit (IRU) and Earth Sensor Assembly (ESA) for attitude determination and achieves specified attitude control accuracy. Regarding fault tolerance of hybrid navigation, by employing FDIR system, the automatic recovery from failure modes has been proven in the real orbit operations, and the highly robust AOCS was developed. Features of new FDIR are shown below. (a)The FDIR not only monitors anomalies of AOCS components but evaluate the attitude determination of hybrid navigation in comparison with the attitude determination of normal navigation operates independently. (b)The FDIR in case of anomaly turns into the normal navigation mode and maintains continuity of almost earth observation mission. The approach and algorithm developed in this FDIR design can be applied to next earth observing satellite required the precise attitude control accuracy.

  14. Earth and ocean dynamics satellites and systems

    NASA Technical Reports Server (NTRS)

    Vonbun, F. O.

    1975-01-01

    An overview is presented of the present state of satellite and ground systems making observations of the dynamics of the solid earth and the oceans. Emphasis is placed on applications of space technology for practical use. Topics discussed include: satellite missions and results over the last two decades in the areas of earth gravity field, polar motions, earth tides, magnetic anomalies, and satellite-to-satellite tracking; laser ranging systems; development of the Very Long Baseline Interferometer; and Skylab radar altimeter data applications.

  15. A Global Observing System for Mars: The dual satellite Mars Astrobiology and Climate Observatory (MACO)

    NASA Astrophysics Data System (ADS)

    Kursinski, E. R.; Lyons, J.; Newman, C.; Richardson, M. I.; Ward, D.; Otarola, A. C.

    2009-12-01

    We summarize a planetary decadal survey white paper describing the rationale for and key elements of a dual satellite orbiting mission (DSM) concept called the Mars Astrobiology and Climate Observatory (MACO). MACO uses mm-wavelength satellite to satellite (sat-sat) occultations in combination with solar occultations (SO) to answer and strongly constrain many key lower and middle atmosphere Mars science questions previously considered unachievable from orbit. On the climate side, MACO would focus on the hydrological, dust and energy cycles of Mars. MACO would measure the transport of water in the present Martian climate, identify sources and sinks and constrain processes in order to better understand present and past Martian climate and glacial and subsurface water reservoirs. Dust-penetrating, satellite-to-satellite mm-wave occultations would profile water vapor to 3%, temperature to 0.4K, geopotential height of pressure to 10 m, line of sight winds to < 2 m/s and balanced winds via pressure gradients, as well turbulence and certain trace constituents with 60 meter diffraction limited vertical resolution and high precision extending down to the surface. A prototype mm-wave occultation instrument will be demonstrated in 2010 via high altitude aircraft to aircraft occultations. MACO will make coincident thermal IR and shortwave measurements to characterize airborne dust to understand dust storm initiation and evolution and how atmospheric dust concentrations are maintained in general. The combination of sensitivity, accuracy and vertical resolution from the satellite to satellite occultation is simply not possible with radiometers and will provide ~30,000 globally distributed near-entry probe quality profiles each Martian year profiling the boundary layer and exchange between the atmosphere and surface. A near-IR solar occultation instrument, such as the French SOIR or a derivative of the Canadian ACE FTIR instrument, would survey chemical trace species such as methane in the Martian atmosphere to look for signatures of subsurface processes related to possible habitable zones and life. MACO’s winds will be key in tracing plumes back to their source regions. Proposed near-surface ion-related heterogeneous chemistry will be assessed by profiling near surface concentrations of H2O2, H2O and dust to look for predicted enhancements in of H2O2 and how they vary with H2O and dust concentrations. MACO’s combined capabilities are a superset of the Mars Science Orbiter (MSO) recommended by the Calvin et al. (2007) report. MACO would fit as a moderate scale mission in the 2016 launch opportunity. Alternatively, since NASA and ESA have recently announced their intent to fly a single orbiter, trace gas mission in 2016, the MACO mm occultation receiver (which can also measure thermal emission and solar occultations) could be flown on that mission and the occultation transmitter could be carried on another mission flown by an international partner such as Japan or India.

  16. Satellite communications system 'Tyulpan'

    NASA Astrophysics Data System (ADS)

    Tchuyan, R. K.; Tarasov, E. V.; Belousov, A. P.; Balyk, V. M.; Kovtunenko, V. M.; Morozov, V. A.; Andreev, V. A.; v'yunenko, K. A.

    1993-10-01

    A concept of the satellite communication system called 'Tyulpan' (because or its tulip-resembling shape) is considered. This conception envisages the use of six satellites-retranslators installed on high-latitude elliptic orbits. Such a system can provide the communication for mean- and high-latitude region of Europe, Asia, and America. For the communication, super small ground stations of 0.4 m in diameter can be used. In the development of system conception, the already existing technical solutions and possibility of conversion or existing installations of military destination were taken into account. Therefore, the system considered can be realized at the earliest possible date.

  17. The Effect of Environmental Conditions on Tropical Deep Convective Systems Observed from the TRMM Satellite

    NASA Technical Reports Server (NTRS)

    Lin, Bing; Wielicki, Bruce A.; Minnis, Patrick; Chambers, Lin H.; Xu, Kuan-Man; Hu, Yongxiang; Fan, Tai-Fang

    2005-01-01

    This study uses measurements of radiation and cloud properties taken between January and August 1998 by three Tropical Rainfall Measuring Mission (TRMM) instruments, the Clouds and the Earth's Radiant Energy System (CERES) scanner, the TRMM Microwave Imager (TMI), and the Visible and InfraRed Scanner (VIRS), to evaluate the variations of tropical deep convective systems (DCS) with sea surface temperature (SST) and precipitation. This study finds that DCS precipitation efficiency increases with SST at a rate of approx. 2%/K. Despite increasing rainfall efficiency, the cloud areal coverage rises with SST at a rate of about 7%/K in the warm tropical seas. There, the boundary layer moisture supply for deep convection and the moisture transported to the upper troposphere for cirrus-anvil cloud formation increase by approx. 6.3%/K and approx. 4.0%/K, respectively. The changes in cloud formation efficiency, along with the increased transport of moisture available for cloud formation, likely contribute to the large rate of increasing DCS areal coverage. Although no direct observations are available, the increase of cloud formation efficiency with rising SST is deduced indirectly from measurements of changes in the ratio of DCS ice water path and boundary layer water vapor amount with SST. Besides the cloud areal coverage, DCS cluster effective sizes also increase with precipitation. Furthermore, other cloud properties, such as cloud total water and ice water paths, increase with SST. These changes in DCS properties will produce a negative radiative feedback for the earth's climate system due to strong reflection of shortwave radiation by the DCS. These results significantly differ from some previous hypothesized dehydration scenarios for warmer climates, and have great potential in testing current cloud-system resolving models and convective parameterizations of general circulation models.

  18. Recent Greenland ice mass loss by drainage system from satellite gravity observations.

    PubMed

    Luthcke, S B; Zwally, H J; Abdalati, W; Rowlands, D D; Ray, R D; Nerem, R S; Lemoine, F G; McCarthy, J J; Chinn, D S

    2006-11-24

    Mass changes of the Greenland Ice Sheet resolved by drainage system regions were derived from a local mass concentration analysis of NASA-Deutsches Zentrum für Luftund Raumfahrt Gravity Recovery and Climate Experiment (GRACE mission) observations. From 2003 to 2005, the ice sheet lost 101 +/- 16 gigaton/year, with a gain of 54 gigaton/year above 2000 meters and a loss of 155 gigaton/year at lower elevations. The lower elevations show a large seasonal cycle, with mass losses during summer melting followed by gains from fall through spring. The overall rate of loss reflects a considerable change in trend (-113 +/- 17 gigaton/year) from a near balance during the 1990s but is smaller than some other recent estimates. PMID:17053112

  19. Satellite Observations for Detecting and Tracking Changes in Atmospheric Composition

    EPA Science Inventory

    The international scientific community's Integrated Global Atmosphere Chemistry Observation System report outlined a plan for ground-based, airborne and satellite Measurements, and models to integrate the observations into a 4-dimensional representation of the atmosphere (space a...

  20. Automatic derivation of earth observation products from satellite data within the Siberian Earth System Science Cluster (SIB-ESS-C)

    NASA Astrophysics Data System (ADS)

    Eberle, J.; Schmullius, C. C.

    2011-12-01

    The Siberian Earth System Science Cluster (SIB-ESS-C) established at the University of Jena (Germany) is a spatial data infrastructure implementing standards published by the Open Geospatial Consortium (OGC) and the International Organization for Standardization (ISO) aimed at providing researchers with focus on Siberia with the technical means for data discovery, data access, data publication and data analysis in work with earth observation data. At the current development stage the SIB-ESS-C system comprises a federated metadata catalogue accessible through the SIB-ESS-C Web Portal or from any OGC-CSW compliant client. The Web Portal also contains a simple map-like visualization component which is currently being extended to a comprehensive visualization and analysis tool. The visualization component enables users to overlay different dataset found during a catalogue search. All data products are accessible as Web Mapping, Web Feature or Web Coverage Services allowing users to directly incorporate the data into their application. New developments aims on automatic registration and processing of raw earth observation data to derive permanently earth observation products. A data registry system within a whole process system including process chains to implement algorithms is currently designed. This will be extended with a system to process these incoming data automatically and permanently, depending on registered algorithms. Algorithms should know which input data is necessary and registered data should know which algorithms could be executed on it. This paper describes current developments as well as future ideas to build up a usefull and userfriendly access to satellite data, algorithms and therefrom derived products with state of the art web technologies and standards of the OGC.

  1. A Geopause satellite system concept.

    NASA Technical Reports Server (NTRS)

    Siry, J. W.

    1973-01-01

    The Geopause satellite system concept offers promising approaches in connection with four different problem areas. A typical Geopause satellite orbit has a 14-hour period, a mean height of about 4.6 earth radii, and is nearly circular, polar, and normal to the ecliptic. At this height only a relatively few gravity terms have uncertainties corresponding to orbital perturbations above the decimeter level. The Geopause satellite system also provides the tracking geometery and coverage needed for determining the orbit, the tracking system biases, and the station locations. Studies indicate that the Geopause satellite, tracked with a 2-cm ranging system from nine NASA affiliated sites, can yield decimeter station location accuracies. Five or more fundamental stations well distributed in longitude can view Geopause over the North Pole. This means not only that redundant data are available for determining tracking system biases, but also that both components of the polar motion can be observed frequently. When tracking Geopause, the NASA sites become a two-hemisphere configuration which is ideal for a number of earth physics applications such as the observation of the polar motion with a time resolution of a fraction of a day.

  2. Orbit Design of Earth-Observation Satellite

    NASA Astrophysics Data System (ADS)

    Owis, Ashraf

    The purpose of this study is to design a reliable orbit for a medium-resolution scientific satellite to observe Earth for developmental issues such as water resources, agricultural, and industrial. To meet this objective this study firstly, defines the mission, secondly, determines mission constraints, thirdly, design the attitude and orbit control system. As for the observation requirements, and the revisit time are provided as a function of the orbital parameters. Initial orbital parameters are obtained by optimal analysis between observation characteristics and attitude and orbit maintenance costs. Long term station-keeping strategies will be provided for the proposed solutions. Impulsive control will be investigated to provide a reliable and affordable attitude and orbit control system.

  3. Severe storms observing satellite (STORMSAT)

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The primary payload for this satellite is the Advanced Atmospheric Sounding and Imaging Radiometer which will perform precise infrared temperature sounding and visible/infrared imaging from geostationary orbit. A secondary payload instrument which may be utilized on STORMSAT is the Microwave Atmospheric Sounding Radiometer which provides an independent set of temperature and humidity sounding in cloudy, meteorologically active regions. The study provides satellite designs and identifies mission-unique subsystems using the Multimission Modular Spacecraft using a Shuttle/Interim Upper Stage launch vehicle.

  4. The Severe Storms Observation Satellite /SSOS/

    NASA Technical Reports Server (NTRS)

    Shenk, W. E.; Raskin, W. H.; Flatow, F. S.; Quann, J. J.

    1975-01-01

    The objective of the Severe Storms Observation Satellite (SSOS) is to continuously observe meteorological phenomena from geosynchronous altitude and to acquire data whose analysis will lead to a better understanding, early detection, and prediction of severe storms and other significant mesoscale events such as dust storms. Details are discussed as to the Advanced Atmospheric Sounding and Imaging Radiometer designed for SSOS, the use of a special spacecraft for an R&D mission, data acquisition, and data processing and analysis. The required accurate vertical temperature and moisture profiles as well as high temporal and spatial resolution images can best be obtained by a three-axis stabilized system, which offers approximately an order of magnitude sensing improvement over a comparable spinning system due to its capability to continuously view the earth. A block diagram of the severe storm analysis system is included.

  5. Applications systems verification and transfer project. Volume 4: Operational applications of satellite snow cover observations. Colorado Field Test Center

    NASA Technical Reports Server (NTRS)

    Shafer, B. A.; Leaf, C. F.; Danielson, J. A.; Moravec, G. F.

    1981-01-01

    The study was conducted on six watersheds ranging in size from 277 km to 3460 km in the Rio Grande and Arkansas River basins of southwestern Colorado. Six years of satellite data in the period 1973-78 were analyzed and snowcover maps prepared for all available image dates. Seven snowmapping techniques were explored; the photointerpretative method was selected as the most accurate. Three schemes to forecast snowmelt runoff employing satellite snowcover observations were investigated. They included a conceptual hydrologic model, a statistical model, and a graphical method. A reduction of 10% in the current average forecast error is estimated when snowcover data in snowmelt runoff forecasting is shown to be extremely promising. Inability to obtain repetitive coverage due to the 18 day cycle of LANDSAT, the occurrence of cloud cover and slow image delivery are obstacles to the immediate implementation of satellite derived snowcover in operational streamflow forecasting programs.

  6. The Navy Navigation Satellite System (TRANSIT)

    NASA Astrophysics Data System (ADS)

    Danchik, R. J.

    1984-12-01

    The present article provides an update on the status of the Navy Navigation Satellite System (Transit). It is pointed out, that, in 1958, research scientists at the Applied Physics Laboratory (APL) solved the orbit of the first Russian satellite, Sputnik-1, by analysis of the observed Doppler shift of its transmitted signal. This result led immediately to the concept of satellite navigation and the development of the U.S. Navy Navigation Satellite System (Transit) by APL, to provide position fixes for the Fleet Ballistic Missile Weapon System submarines. At the present time, 26 years after its conception, the system is mature. Beginning with the release of the system to industry in July 1967, it has been used by military and civilian navigators for position fixing and for surveying. Attention is given to system reliability, developments regarding the constellation of satellites, satellite configurations, the users of the Transit system, and plans to continue operation of Transit until 1994.

  7. Satellite-observed Characteristics of Mesoscale Convective Systems over the Tibetan Plateau in Warm Season

    NASA Astrophysics Data System (ADS)

    Wang, D.; Fu, W.

    2014-12-01

    Using the data sets of the FY-2C and FY-2E hourly equivalent temperature of black body (TBB) from 2005 to 2010, the mesoscale convective systems (MCSs) in warm season (March-September) over the Tibetan Plateau are investigated. The large-scale environmental characteristics during the MCSs' life cycle are also analyzed using the NCEP FNL data. The results show that the hinterland of the Tibetan Plateau is the high-frequency occurrence area of MCSs. There is noticeable inter-monthly and diurnal variation in the distribution of MCSs over the Tibetan Plateau. The MCSs precipitation occurs more frequently in the summer season and from sunset to midnight. Most of the MCSs over the Tibetan Plateau are eastward propagating, low-speed, short-life meso-? convective systems. With respect to the large-scale atmospheric condition, the results indicate that in the upper troposphere there is a wind divergence center, and in the low troposphere there is a moisture convergence center associated with strong upward vertical motion, that is beneficial to the occurrence of strong convection. Also, in the mid troposphere (500 hPa) there exists an eastward positive vorticity advection, which might be a reason for the MCSs moving toward the east. The large-scale atmospheric condition in spring is different from that in summer. The vertical wind shear is the main factor for the MCSs to occur in spring, and the unstable atmosphere structure is the reason for the MCSs to occur in summer.

  8. Laser satellite power systems

    SciTech Connect

    Walbridge, E.W.

    1980-01-01

    A laser satellite power system (SPS) converts solar power captured by earth-orbiting satellites into electrical power on the earth's surface, the satellite-to-ground transmission of power being effected by laser beam. The laser SPS may be an alternative to the microwave SPS. Microwaves easily penetrate clouds while laser radiation does not. Although there is this major disadvantage to a laser SPS, that system has four important advantages over the microwave alternative: (1) land requirements are much less, (2) radiation levels are low outside the laser ground stations, (3) laser beam sidelobes are not expected to interfere with electromagnetic systems, and (4) the laser system lends itself to small-scale demonstration. After describing lasers and how they work, the report discusses the five lasers that are candidates for application in a laser SPS: electric discharge lasers, direct and indirect solar pumped lasers, free electron lasers, and closed-cycle chemical lasers. The Lockheed laser SPS is examined in some detail. To determine whether a laser SPS will be worthy of future deployment, its capabilities need to be better understood and its attractiveness relative to other electric power options better assessed. First priority should be given to potential program stoppers, e.g., beam attenuation by clouds. If investigation shows these potential program stoppers to be resolvable, further research should investigate lasers that are particularly promising for SPS application.

  9. Monitoring Changes in Water Resources Systems Using High Resolution Satellite Observations: Application to Lake Urmia

    NASA Astrophysics Data System (ADS)

    Norouzi, H.; AghaKouchak, A.; Madani, K.; Mirchi, A.; Farahmand, A.; Conway, C.

    2013-12-01

    Lake Urmia with its unique ecosystem in northwestern Iran is the second largest saltwater lake in the world. It is home of more than 300 species of birds, reptiles, and mammals with high salinity level of more than 300 g/l. In recent years, a significant water retreat has occurred in this lake. In this study, we tried to monitor the desiccation of the lake over more than four decades using remote sensing observations. Multi-spectral high-resolution LandSat images of the Lake Urmia region from 1972 to 2012 were acquired to derive the lake area. The composite maps of the lake were created, and a Bayesian Maximum Likelihood classification technique was used to classify land and water in the composite maps. The time series of the lake area reveals that it has shrunk by more than 40% in the past ten years. Moreover, water budget related components such as precipitation, soil moisture, and drought indices from remote sensing of the lake basin were utilized to investigate if droughts or climate change are the primary driving forces behind this phenomenon. These analyses show that the retreat of the lake is not related to droughts or global climate change as it has survived several drought events before year 2000. Similar analyses conducted on Lake Van located about 400 km west of Lake Urmia with very similar climate pattern revealed no significant areal change despite the lake's exposure to similar drought events. These results raise serious concern about the destructive role of unbridled development coupled with supply-oriented water management scheme driven by a classic upstream-downstream competition for water in the Lake Urmia region. There is an urgent need to investigate sustainable restoration initiatives for Lake Urmia in order to prevent an environmental disaster comparable to catastrophic death of Aral Sea.

  10. Satellite freeze forecast system

    NASA Technical Reports Server (NTRS)

    Martsolf, J. D. (principal investigator)

    1983-01-01

    Provisions for back-up operations for the satellite freeze forecast system are discussed including software and hardware maintenance and DS/1000-1V linkage; troubleshooting; and digitized radar usage. The documentation developed; dissemination of data products via television and the IFAS computer network; data base management; predictive models; the installation of and progress towards the operational status of key stations; and digital data acquisition are also considered. The d addition of dew point temperature into the P-model is outlined.

  11. The artificial satellite observation chronograph controlled by single chip microcomputer.

    NASA Astrophysics Data System (ADS)

    Pan, Guangrong; Tan, Jufan; Ding, Yuanjun

    1991-06-01

    The instrument specifications, hardware structure, software design, and other characteristics of the chronograph mounting on a theodolite used for artificial satellite observation are presented. The instrument is a real time control system with a single chip microcomputer.

  12. Satellite business networks and systems

    NASA Astrophysics Data System (ADS)

    Kadar, I.; Eaves, R. E.

    1985-07-01

    A compilation of articles concerning the technical aspects of satellite business networks is presented. Among the topics discussed are: flexible satellite data services; service satellite systems for the Atlantic Ocean region; and the design of a 30/20 GHz international business teleconferencing system. Consideration is also given to issues of network architecture including the performance of computer networks in accessing satellite links; advanced satellite communications systems with integrated transponders; full duplex teleconferencing via Intelsat V F-2 and OTS-2 at ll/14 GHz; and digital facsimile communication over satellite links. Among other topics discussed are: cryptographic techniques for satellite networks; a Codec system for world wide video conferencing; and regenerative SCPC satellite communications systems.

  13. Scheduling of VLBI satellite observations for an improved ITRF

    NASA Astrophysics Data System (ADS)

    Hellerschmied, Andreas; Böhm, Johannes; Neidhardt, Alexander; Haas, Rüdiger; Kodet, Jan; Plank, Lucia

    2015-04-01

    Observations of Earth orbiting satellites with the Very Long Baseline Interferometry (VLBI) technique provide a variety of new possibilities and promote the integration of different geodetic techniques, which is one of the main purposes of GGOS, the Global Geodetic Observing System of the IAG. Promising applications can be found e.g. in the field of inter-technique frame ties, having the potential to improve future realizations of the International Terrestrial Reference Frame (ITRF). Although several test observations to GNSS satellites have been carried out in recent years, this approach is still far away from being applied operationally. Difficulties already start at the observation planning level, with the standard VLBI scheduling software not being prepared to include satellites as observation targets in the required control files. The newly developed satellite scheduling module of the Vienna VLBI Software (VieVS) for the planning of satellite observations with VLBI antennas offers a solution to this. It allows the user to prepare schedules for selected satellites, which are simultaneously visible from a chosen station network. The generated schedule files in the current VEX format provide the possibility to carry out actual satellite observations with standard geodetic antennas, e.g. of the IVS network. The antennas can be controlled directly with the issued schedule files by commanding sequences of discrete celestial positions, without the requirement of modifications in the antenna control intended for satellite tracking. In January 2014 several successful test observations to GLONASS satellites were carried out on the baseline Onsala-Wettzell based on schedules generated with VieVS. Correlations of the recorded data showed that the observations - and therefore the scheduling with VieVS - were successful. The next step is to update the new software for the possibility to combine observations to satellites and to quasars in one schedule. The development of convenient scheduling software in the form of the new VieVS module is important to promote further research and development in this specific field.

  14. Observing Climate with Satellites - Are We on Thin Ice?

    NASA Technical Reports Server (NTRS)

    Tucker, Compton

    2012-01-01

    The Earth s climate is determined by irradiance from the Sun and properties of the atmosphere, oceans, and land that determine the reflection, absorption, and emission of energy within our atmosphere and at the Earth s surface. Since the 1970s, Earth-viewing satellites have complimented non-satellite geophysical observations with consistent, quantitative, and spatially-continuous measurements that have led to an unprecedented understanding of the Earth s climate system. I will describe the Earth s climate system as elaborated by satellite and in situ observations, review arguments against global warming, and show the convergence of evidence for human-caused warming of our planet.

  15. ASTER satellite observations for international disaster management

    USGS Publications Warehouse

    Duda, K.A.; Abrams, M.

    2012-01-01

    When lives are threatened or lost due to catastrophic disasters, and when massive financial impacts are experienced, international emergency response teams rapidly mobilize to provide urgently required support. Satellite observations of affected areas often provide essential insight into the magnitude and details of the impacts. The large cost and high complexity of developing and operating satellite flight and ground systems encourages international collaboration in acquiring imagery for such significant global events in order to speed delivery of critical information to help those affected, and optimize spectral, spatial, and temporal coverage of the areas of interest. The International Charter-Space and Major Disasters was established to enable such collaboration in sensor tasking during times of crisis and is often activated in response to calls for assistance from authorized users. Insight is provided from a U.S. perspective into sensor support for Charter activations and other disaster events through a description of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), which has been used to support emergency situations for over a decade through its expedited tasking and near real-time data delivery capabilities. Examples of successes achieved and challenges encountered in international collaboration to develop related systems and fulfill tasking requests suggest operational considerations for new missions as well as areas for future enhancements.

  16. Magnetopause structure from satellite observations

    NASA Technical Reports Server (NTRS)

    Sonnerup, B. U. O.

    1979-01-01

    Observations on magnetopause structure are reported. Major topics covered include: classical reconnection, transport mechanisms, magnetospheric boundary layers, tearing modes, and Jupiter's magnetopause.

  17. Lightning-Generated Whistler Waves Observed by Probes On The Communication/Navigation Outage Forecast System Satellite at Low Latitudes

    NASA Technical Reports Server (NTRS)

    Holzworth, R. H.; McCarthy, M. P.; Pfaff, R. F.; Jacobson, A. R.; Willcockson, W. L.; Rowland, D. E.

    2011-01-01

    Direct evidence is presented for a causal relationship between lightning and strong electric field transients inside equatorial ionospheric density depletions. In fact, these whistler mode plasma waves may be the dominant electric field signal within such depletions. Optical lightning data from the Communication/Navigation Outage Forecast System (C/NOFS) satellite and global lightning location information from the World Wide Lightning Location Network are presented as independent verification that these electric field transients are caused by lightning. The electric field instrument on C/NOFS routinely measures lightning ]related electric field wave packets or sferics, associated with simultaneous measurements of optical flashes at all altitudes encountered by the satellite (401.867 km). Lightning ]generated whistler waves have abundant access to the topside ionosphere, even close to the magnetic equator.

  18. Estimating Soil Moisture from Satellite Microwave Observations

    NASA Technical Reports Server (NTRS)

    Owe, M.; VandeGriend, A. A.; deJeu, R.; deVries, J.; Seyhan, E.

    1998-01-01

    Cooperative research in microwave remote sensing between the Hydrological Sciences Branch of the NASA Goddard Space Flight Center and the Earth Sciences Faculty of the Vrije Universiteit Amsterdam began with the Botswana Water and Energy Balance Experiment and has continued through a series of highly successful International Research Programs. The collaboration between these two research institutions has resulted in significant scientific achievements, most notably in the area of satellite-based microwave remote sensing of soil moisture. The Botswana Program was the first joint research initiative between these two institutions, and provided a unique data base which included historical data sets of Scanning Multifrequency Microwave Radiometer (SN4NM) data, climate information, and extensive soil moisture measurements over several large experimental sites in southeast Botswana. These data were the basis for the development of new approaches in physically-based inverse modelling of soil moisture from satellite microwave observations. Among the results from this study were quantitative estimates of vegetation transmission properties at microwave frequencies. A single polarization modelling approach which used horizontally polarized microwave observations combined with monthly composites of Normalized Difference Vegetation Index was developed, and yielded good results. After more precise field experimentation with a ground-based radiometer system, a dual-polarization approach was subsequently developed. This new approach realized significant improvements in soil moisture estimation by satellite. Results from the Botswana study were subsequently applied to a desertification monitoring study for the country of Spain within the framework of the European Community science research programs EFEDA and RESMEDES. A dual frequency approach with only microwave data was used for this application. The Microwave Polarization Difference Index (MPDI) was calculated from 37 GHz data and used to derive the one-way canopy transmissivity. Using a simple radiative transfer model, this information was combined with horizontally polarized 6.6 GHz SMMR observations to derive a 9-year time series of soil moisture for all of Spain at a one quarter degree spatial scale. Both day and night SMMR observations were used independently, in order to check the consistency of the results. A first order Fourier Transform was performed on the mean monthly soil moisture values to identify major characteristics of time series such as trend, amplitude, and phase shift.

  19. New progress in the CCD astrometric observation of natural satellites.

    NASA Astrophysics Data System (ADS)

    Peng, Qingyu

    1998-06-01

    CCD astrometric observation of natural satellites is important for the spacecraft probation of the outer planets, the planetary physics, and the link between different astronomical reference systems. In this paper the author introduces the difficulties on CCD observation of natural satellites by the long focus telescope and different solving methods and mainly reviews and describes the CCD image processing and reducing methods. At last, some factors affecting the accuracy of the positional determination of natural satellites and the accuracy of the newest results are also introduced.

  20. First optical observations of artificial Earth's satellites

    NASA Astrophysics Data System (ADS)

    Rykhlova, L. V.

    2008-08-01

    A review of the first optical observations of the artificial satellites in the USSR as well as in former communist countries (DDR, Romania,Poland) is given. The role by Alla G. Masevich, I.D. Zhongolovich and Yu.V. Batrakov is underlined in the organization of observations.

  1. NTT domestic satellite communications system

    NASA Astrophysics Data System (ADS)

    Suzuki, R.; Hayashizaki, H.

    1984-10-01

    The NTT domestic satellite communications system is described, and its state of operation is discussed based on commercial service experience. The major parameters of the system and system satellites are given, and the transmission circuits between regional centers and between remote islands and the mainland are shown. The characteristics of the NTT earth stations are presented. Performance data are given to show the effect of rain attenuation and of sun transit on the satellite circuits.

  2. Measuring Snowfall From Satellite Microwave Observations

    NASA Astrophysics Data System (ADS)

    Liu, G.

    2014-12-01

    Snowfall is one of the important components in the global hydrological cycle. However, snowfall retrieval from satellite observations is very difficult (compared to rainfall retrieval) because of several reasons including weak radiative signal, surface contamination, cloud liquid water masking, etc. Several satellite sensors currently in operation are potentially capable of detecting and estimating snowfall, for example, cloud radar onboard CloudSat and high frequency microwave radiometers (SSMIS, MHS, GMI) on NOAA, MetOP, S-NPP, DMSP and GPM satellites. In this paper, we report our research results on how to best use these sensors to extract snowfall information. Specifically, we (1) studied the global snowfall frequency and rate distributions based on multiple years of CloudSat observations; (2) investigated the optimal channel selection for snowfall retrieval using collocated satellite SSMIS (19-183 GHz) and ground radar (NMQ) data; (3) developed a retrieval algorithm in which radar data (CloudSat and/or NMQ) are used as truth to train high-frequency passive microwave data and use high-frequency passive microwave data to broaden spatial and temporal coverage. Finally, retrievals based on observations from several satellites are compared with each other and compared with surface observations.

  3. Severe storms observing satellite study

    NASA Technical Reports Server (NTRS)

    Iwens, R. P.; Stern, D. A.

    1976-01-01

    Payload distribution and the attitude control system for the multi-mission modular spacecraft/StormSat configuration are discussed. The design of the advanced atmospheric sounder and imaging radiometer (AASIR) gimbal drive and its servomechanism is described. Onboard data handling, data downlink communications, and ground data handling systems are developed. Additional topics covered include: magnetic unloading at synchronous altitude, north-south stationkeeping, and the feasibility and impact of flying the microwave atmospheric sounding radiometer (MASR) as an additional payload.

  4. Applications of Satellite Observations to Aerosol Analyses and Forecasting using the NAAPS Model and the DataFed Distributed Data System

    NASA Astrophysics Data System (ADS)

    Husar, R. B.; Hoijarvi, K.; Westphal, D. L.; Scheffe, R.; Keating, T.; Frank, N.; Poirot, R.; DuBois, D. W.; Bleiweiss, M. P.; Eberhard, W. L.; Menon, R.; Sethi, V.; Deshpande, A.

    2012-12-01

    Near-real-time (NRT) aerosol characterization, forecasting and decision support is now possible through the availability of (1) surface-based monitoring of regional PM concentrations, (2) global-scale columnar aerosol observations through satellites; (3) an aerosol model (NAAPS) that is capable of assimilating NRT satellite observations; and (4) an emerging cyber infrastructure for processing and distribution of data and model results (DataFed) for a wide range of users. This report describes the evolving NRT aerosol analysis and forecasting system and its applications at Federal and State and other AQ Agencies and groups. Through use cases and persistent real-world applications in the US and abroad, the report will show how satellite observations along with surface data and models are combined to aid decision support for AQ management, science and informing the public. NAAPS is the U.S. Navy's global aerosol and visibility forecast model that generates operational six-day global-scale forecasts for sulfate, dust, sea salt, and smoke aerosol. Through NAVDAS-AOD, NAAPS operationally assimilates filtered and corrected MODIS MOD04 aerosol optical depths and uses satellite-derived FLAMBÉ smoke emissions. Washington University's federated data system, DataFed, consist of a (1) data server which mediates the access to AQ datasets from distributed providers (NASA, NOAA, EPA, etc.,); (2) an AQ Data Catalog for finding and accessing data; and (3) a set of application programs/tools for browsing, exploring, comparing, aggregating, fusing data, evaluating models and delivering outputs through interactive visualization. NAAPS and DataFed are components of the Global Earth Observation System of Systems (GEOSS). Satellite data support the detection of long-range transported wind-blown dust and biomass smoke aerosols on hemispheric scales. The AQ management and analyst communities use the satellite/model data through DataFed and other channels as evidence for Exceptional Events (EE) as defined by EPA; i.e., Sahara dust impact on Texas and Florida, local dusts events in the Southwestern U.S. and Canadian smoke events over the Northeastern U.S. Recent applications include the impact analysis of a major Saudi Arabian dust event on Mumbai, India air quality. The NAAPS model and the DataFed tools can visualize the dynamic AQ events as they are manifested through the different sensors. Satellite-derived aerosol observations assimilated into NAAPS provide estimates of daily emission rates for dust and biomass fire sources. Tuning and reconciliation of the observations, emissions and models constitutes a key and novel contribution yielding a convergence toward the true five-dimensional (X, Y, Z, T, Composition) characterization of the atmospheric aerosol data space. This observation-emission-model reconciliation effort is aided by model evaluation tools and supports the international HTAP program. The report will also discuss some of the challenges facing multi-disciplinary, multi-agency, multi-national applications of integrated observation-modeling system of systems that impede the incorporation of satellite observations into AQ management decision support systems.

  5. Arctic Warming Signals from Satellite Observations

    NASA Technical Reports Server (NTRS)

    Comiso, Josefino C.

    2005-01-01

    Global warming signals are expected to be amplified in the Arctic primarily because of ice-albedo feedback associated with the high reflectivity of ice and snow that blankets much of the region. The Arctic had been a poorly explored territory basically because of its general inaccessibility on account of extremely harsh weather conditions and the dominant presence of thick perennial ice in the region. The advent of satellite remote sensing systems since the 1960s, however, enabled the acquisition of synoptic data that depict in good spatial detail the temporal changes of many Arctic surface parameters. Among the surface parameters that have been studied using space based systems are surface temperature, sea ice concentration, snow cover, surface albedo and phytoplankton concentration. Associated atmospheric parameters, such as cloud cover, temperature profile, ozone concentration, and aerosol have also been derived. Recent observational and phenomenological studies have indeed revealed progressively changing conditions in the Arctic during the last few decades (e g , Walsh et al. 1996; Serreze et al 2000; Comiso and Parkinson 2004). The changes included declines in the extent and area of surfaces covered by sea ice and snow, increases in melt area over the Greenland ice sheets, thawing of the permafrost, warming in the troposphere, and retreat of the glaciers. These observations are consistent with the observed global warming that has been associated with the increasing concentration of greenhouse gases in the atmosphere (Karl and Trenberth 2003) and confirmed by modeling studies (Holland and Bitz, 2003). The Arctic system, however, is still not well understood complicated by a largely fluctuating wind circulation and atmospheric conditions (Proshutinsky and Johnson 1997) and controlled by what is now known as the Arctic Oscillation (AO) which provides a measure of the strength of atmospheric activities in the region (Thompson and Wallace 1998). Meanwhile, the observed Arctic conditions since the 1970s have been shown to exhibit a linear behavior that directly contradicts what has been expected from the A0 (Overland, 2005). The decade of the 1990s has been regarded as the warmest decade in the last century and current data indicates that the 2000s may be even a warmer decade than the 1990s further supporting the linear variability. In this paper, we use satellite data to gain insights into the warming Arctic and how the abnormally warm conditions during the last few years are reflected in the region.

  6. Satellite Power System (SPS)

    NASA Technical Reports Server (NTRS)

    Edler, H. G.

    1978-01-01

    Potential organizational options for a solar power satellite system (SPS) were investigated. Selection and evaluation criteria were determined to include timeliness, reliability, and adequacy to contribute meaningfully to the U.S. supply; political feasibility (both national and international); and cost effectiveness (including environmental and other external costs). Based on these criteria, four organizational alternatives appeared to offer reasonable promise as potential options for SPS. A large number of key issues emerged as being factors which would influence the final selection process. Among these issues were a variety having to do with international law, international institutions, environmental controls, economics, operational flexibility, congressional policies, commercial-vs-governmental ownership, national dedication, and national and operational stategic issues.

  7. Astrometric observations of planetary satellites at the Abastumani Astrophysical Observatory

    NASA Astrophysics Data System (ADS)

    Kiseleva, T. P.; Chanturiya, S. M.; Vasil'eva, T. A.; Kalinichenko, O. A.

    2012-11-01

    We present and discuss the results of the astrometry project during which we observed the satellites of Mars, Jupiter, Saturn, Uranus, and Neptune at the Abastumani Astrophysical Observatory (Georgia) between 1983 and 1994. Observations at the Abastumani Observatory were performed with the double Zeiss astrograph (DZA: D/ F = 400/3024 mm) and AZT-11 telescope ( F = 16 m). We processed a large array of observations and determined exact coordinates of the planets and their satellites in a system of reference stars of modern catalogues as well as relative coordinates of the satellites. The results were compared with modern ephemerides using the MULTI-SAT software. The comparison enabled us to estimate the accuracy of observations (their random and systematic uncertainties) and the accuracy of modern theories of the motion of planets and their satellites. Random uncertainties of observations are estimated to be 0.10?-0.40? for various objects and observational conditions. Observational results obtained for Uranus, Neptune and the satellites Titania and Oberon were shown to deviate appreciably and systematically from theories of their motion. The results of observations are presented in the Pulkovo database for Solar System bodies that is available at the website http://www.puldb.ru.

  8. Applications systems verification and transfer project. Volume 2: Operational applications of satellite snow-cover observations and data-collection systems in the Arizona test site

    NASA Technical Reports Server (NTRS)

    Schumann, H. H.

    1981-01-01

    Ground surveys and aerial observations were used to monitor rapidly changing moisture conditions in the Salt-Verde watershed. Repetitive satellite snow cover observations greatly reduce the necessity for routine aerial snow reconnaissance flights over the mountains. High resolution, multispectral imagery provided by LANDSAT satellite series enabled rapid and accurate mapping of snow-cover distributions for small- to medium-sized subwatersheds; however, the imagery provided only one observation every 9 days of about a third of the watershed. Low resolution imagery acquired by the ITOSa dn SMS/GOES meteorological satellite series provides the daily synoptic observation necessary to monitor the rapid changes in snow-covered area in the entire watershed. Short term runoff volumes can be predicted from daily sequential snow cover observations.

  9. Global canopy interception from satellite observations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new methodology for retrieving rainfall interception rates from multi satellite observations is presented. The approach makes use of the daily productof the Global Precipitation Climatology Project (GPCP) as driving data and applies Gash’s analytical model to derive interception rates at global sc...

  10. Comparison of filter predictions with satellite observations

    SciTech Connect

    Canavan, G.H.

    1997-10-01

    Satellite observations of meteor entry are used to calibrate a filter model of fragmentation. Predicted sizes and masses compare favorably with data and analytic interpretations for objects of all sizes. However, objects that fragment into many large objects should be treated by the decomposition of the radiation signal into the contributions from the different fragments.

  11. A geopause satellite system concept

    NASA Technical Reports Server (NTRS)

    Siry, J. W.

    1971-01-01

    A typical Geopause satellite orbit has a 14 hour period, a mean height of about 4.6 earth radii, and is nearly circular, polar, and normal to the ecliptic. At this height only a relatively few gravity terms have uncertainties corresponding to orbital perturbations above the decimeter level. The orbit is at the geopotential boundary, the geopause. The few remaining environmental quantities which may be significant can be determined by means of orbit analysis and accelerometers. The Geopause satellite system also provides the tracking geometry and coverage needed for determining the orbit, the tracking system biases and the station locations. Five or more fundamental stations well distributed in longitude can view Geopause over the North Pole. Geopause also provides the basic capability for satellite-to-satellite tracking of drag-free satellites for mapping the gravity field and altimeter satellites for surveying the sea surface topography.

  12. Scheduling Earth Observing Satellites with Evolutionary Algorithms

    NASA Technical Reports Server (NTRS)

    Globus, Al; Crawford, James; Lohn, Jason; Pryor, Anna

    2003-01-01

    We hypothesize that evolutionary algorithms can effectively schedule coordinated fleets of Earth observing satellites. The constraints are complex and the bottlenecks are not well understood, a condition where evolutionary algorithms are often effective. This is, in part, because evolutionary algorithms require only that one can represent solutions, modify solutions, and evaluate solution fitness. To test the hypothesis we have developed a representative set of problems, produced optimization software (in Java) to solve them, and run experiments comparing techniques. This paper presents initial results of a comparison of several evolutionary and other optimization techniques; namely the genetic algorithm, simulated annealing, squeaky wheel optimization, and stochastic hill climbing. We also compare separate satellite vs. integrated scheduling of a two satellite constellation. While the results are not definitive, tests to date suggest that simulated annealing is the best search technique and integrated scheduling is superior.

  13. Use of meteorological satellite observations in weather modification programs

    NASA Technical Reports Server (NTRS)

    Dennis, A. S.; Smith, P. L., Jr.; Biswas, K. R.

    1973-01-01

    The potential value of weather satellite data in field operations of weather modification is appraised. It was found that satellites could play a useful role in operational weather modification projects, particularly in the recognition of treatment opportunities. Satellite cloud photographs and infrared observations appear promising in the identification of treatment opportunities in seeding orographic cloud systems for increased snowpack, in seeding convective clouds for increased rainfall, in identifying hail threats, and in tracking and observing hurricanes as an aid to timing and location of seeding treatments. It was concluded that the potential value of satellite data in the treatment and evaluation phases of operational projects is not as great as in the recognition of treatment opportunity.

  14. The satellite configuration of satellite-TV navigation system

    NASA Astrophysics Data System (ADS)

    Gao, Yu-Ping

    2001-02-01

    The positioning accuracy and availability of navigation system are affected directly by the quality of satellite configuration. The possible satellite configurations for satellite-TV navigation system are discussed and estimated in this paper. The results show that a well setted configuration or a resonable integration of satellite-TV navigation system and Chinese Loran-C will improve the positioning accuracy and availability of the system.

  15. Communications satellite systems capacity analysis

    NASA Technical Reports Server (NTRS)

    Browne, L.; Hines, T.; Tunstall, B.

    1982-01-01

    Analog and digital modulation techniques are compared with regard to efficient use of the geostationary orbit by communications satellites. Included is the definition of the baseline systems (both space and ground segments), determination of interference susceptibility, calculation of orbit spacing, and evaluation of relative costs. It is assumed that voice or TV is communicated at 14/11 GHz using either FM or QPSK modulation. Both the Fixed-Satellite Service and the Broadcasting-Satellite Service are considered. For most of the cases examined the digital approach requires a satellite spacing less than or equal to that required by the analog approach.

  16. Land mobile satellite system requirements

    NASA Technical Reports Server (NTRS)

    Kiesling, J. D.

    1983-01-01

    A Land Mobile Satellite System (LMSS) provides voice, data and related communications services to moving vehicles and persons. Communications between the mobiles and satellite are in the 806-890 MHz band. The satellite translates these signals to a ""fixed services band'' such as 14/12 GHz band (Ku-band), and communicates in this band with fixed terminals called gateways. The gateways are located at convenient places such as telephone switches (which provide entry into the national telephone system), dispatcher headquarters, computer centers, etc. Communications are therefore principally mobile to fixed. A third communications link, also at Ku-band, is needed between the satellite and a single fixed ground station. This link provides satellite command, telemetry and ranging and also provides a network control function. The latter, through a common signalling system, receives requests and assigns channel slots, and otherwise controls, monitors and polices the network and collects billing information.

  17. Land mobile satellite system requirements

    NASA Astrophysics Data System (ADS)

    Kiesling, J. D.

    1983-05-01

    A Land Mobile Satellite System (LMSS) provides voice, data and related communications services to moving vehicles and persons. Communications between the mobiles and satellite are in the 806-890 MHz band. The satellite translates these signals to a ""fixed services band'' such as 14/12 GHz band (Ku-band), and communicates in this band with fixed terminals called gateways. The gateways are located at convenient places such as telephone switches (which provide entry into the national telephone system), dispatcher headquarters, computer centers, etc. Communications are therefore principally mobile to fixed. A third communications link, also at Ku-band, is needed between the satellite and a single fixed ground station. This link provides satellite command, telemetry and ranging and also provides a network control function. The latter, through a common signalling system, receives requests and assigns channel slots, and otherwise controls, monitors and polices the network and collects billing information.

  18. Global Warming: Evidence from Satellite Observations

    NASA Technical Reports Server (NTRS)

    Prabhakara, C.; Iacovazzi, R.; Yoo, J.-M.; Dalu, G.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Observations made in Channel 2 (53.74 GHz) of the Microwave Sounding Unit (MSU) radiometer, flown onboard sequential, sun-synchronous, polar-orbiting NOAA (National Oceanic and Atmospheric Administration) operational satellites, indicate that the mean temperature of the atmosphere over the globe increased during the period 1980 to 1999. In this study, we have minimized systematic errors in the time series introduced by satellite orbital drift in an objective manner. This is done with the help of the onboard warm-blackbody temperature, which is used in the calibration of the MSU radiometer. The corrected MSU Channel 2 observations of the NOAA satellite series reveal that the vertically-weighted global-mean temperature of the atmosphere, with a peak weight near the mid troposphere, warmed at the rate of 0.13 +/- 0.05 K/decade during 1980 to 1999. The global warming deduced from conventional meteorological data that have been corrected for urbanization effects agrees reasonably with this satellite-deduced result.

  19. Global Warming: Evidence from Satellite Observations

    NASA Technical Reports Server (NTRS)

    Prabhakara, C.; Iacovazzi, R., Jr.; Yoo, J.-M.

    2001-01-01

    Observations made in Channel 2 (53.74 GHz) of the Microwave Sounding Unit (MSU) radiometer, flown on-board sequential, sun-synchronous, polar orbiting NOAA operational satellites, indicate that the mean temperature of the atmosphere over the globe increased during the period 1980 to 1999. In this study we have minimized systematic errors in the time series introduced by the satellite orbital drift in an objective manner. This is done with the help the onboard warm black body temperature, which is used in the calibration of the MSU radiometer. The corrected MSU Channel 2 observations of the NOAA satellite series reveal that the vertically weighted global mean temperature of the atmosphere, with a peak weight near the mid-troposphere, warmed at the rate of 0.13 K per decade (with an uncertainty of 0.05 K per decade) during 1980 to 1999. The global warming deduced from conventional meteorological data that have been corrected for urbanization effects agrees reasonably with this satellite deuced result.

  20. Radiocommunications for meteorological satellite systems

    NASA Technical Reports Server (NTRS)

    Walton, B. A.

    1975-01-01

    A general overview is presented of the spectrum utilization and frequency requirements of present and planned meteorological satellite programs. The sensors, and TIROS operational systems are discussed along with the Nimbus and Synchronous Meteorological Satellites. STORMSAT, SEASAT, and the Spacelab are briefly described.

  1. Globally Gridded Satellite observations for climate studies

    USGS Publications Warehouse

    Knapp, K.R.; Ansari, S.; Bain, C.L.; Bourassa, M.A.; Dickinson, M.J.; Funk, C.; Helms, C.N.; Hennon, C.C.; Holmes, C.D.; Huffman, G.J.; Kossin, J.P.; Lee, H.-T.; Loew, A.; Magnusdottir, G.

    2011-01-01

    Geostationary satellites have provided routine, high temporal resolution Earth observations since the 1970s. Despite the long period of record, use of these data in climate studies has been limited for numerous reasons, among them that no central archive of geostationary data for all international satellites exists, full temporal and spatial resolution data are voluminous, and diverse calibration and navigation formats encumber the uniform processing needed for multisatellite climate studies. The International Satellite Cloud Climatology Project (ISCCP) set the stage for overcoming these issues by archiving a subset of the full-resolution geostationary data at ~10-km resolution at 3-hourly intervals since 1983. Recent efforts at NOAA's National Climatic Data Center to provide convenient access to these data include remapping the data to a standard map projection, recalibrating the data to optimize temporal homogeneity, extending the record of observations back to 1980, and reformatting the data for broad public distribution. The Gridded Satellite (GridSat) dataset includes observations from the visible, infrared window, and infrared water vapor channels. Data are stored in Network Common Data Format (netCDF) using standards that permit a wide variety of tools and libraries to process the data quickly and easily. A novel data layering approach, together with appropriate satellite and file metadata, allows users to access GridSat data at varying levels of complexity based on their needs. The result is a climate data record already in use by the meteorological community. Examples include reanalysis of tropical cyclones, studies of global precipitation, and detection and tracking of the intertropical convergence zone.

  2. Satellite Observations for Detecting and Tracking Changes in Atmospheric Composition

    NASA Technical Reports Server (NTRS)

    Neil, Doreen O.; Kondragunbta, Shobha; Osterman, Gregory; Pickering, Kenneth; Pinder, Robert W.; Prados, Ana I.; Szykman, James

    2009-01-01

    The satellite observations provide constraints on detailed atmospheric modeling, including emissions inventories, indications of transport, harmonized data over vast areas suitable for trends analysis, and a link between spatial scales ranging from local to global, and temporal scales from diurnal to interannual. 1 The National Oceanic and Atmospheric Administration's (NOAA) long-term commitments help provide these observations in cooperation with international meteorological organizations. NASA s long-term commitments will advance scientifically important observations as part of its Earth Science Program, and will assist the transition of the science measurements to applied analyses through the Applied Science Program. Both NASA and NOAA have begun to provide near realtime data and tools to visualize and analyze satellite data,2 while maintaining data quality, validation, and standards. Consequently, decision-makers can expect satellite data services to support air quality decision making now and in the future. The international scientific community's Integrated Global Atmosphere Chemistry Observation System Report3 outlined a plan for ground-based, airborne and satellite measurements and models to integrate the observations into a four-dimensional representation of the atmosphere (space and time) to support assessment and policy information needs. This plan is being carried out under the Global Earth Observation System of Systems (GEOSS). Demonstrations of such an integrated capability4 provide new understanding of the changing atmosphere and link policy decisions to benefits for society. In this article, we highlight the use of satellite data to constrain biomass burning emissions, to assess oxides of nitrogen (NO(x)) emission reductions, and to contribute to state implementation plans, as examples of the use of satellite observations for detecting and tracking changes in atmospheric composition.

  3. A web-based tool that combines satellite and weather station observations to support irrigation scheduling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Abstract: The Satellite Irrigation Management Support (SIMS) project combines NASA's Terrestrial Observation and Prediction System (TOPS), Landsat and MODIS satellite imagery, and reference evapotranspiration from surface weather station networks to map daily crop irrigation demand in California in ...

  4. Simulated NASA Satellite Data Products for the NOAA Integrated Coral Reef Observation Network/Coral Reef Early Warning System

    NASA Technical Reports Server (NTRS)

    Estep, Leland; Spruce, Joseph P.

    2007-01-01

    This RPC (Rapid Prototyping Capability) experiment will demonstrate the use of VIIRS (Visible/Infrared Imager/Radiometer Suite) and LDCM (Landsat Data Continuity Mission) sensor data as significant input to the NOAA (National Oceanic and Atmospheric Administration) ICON/ CREWS (Integrated Coral Reef Observation System/Coral Reef Early Warning System). The project affects the Coastal Management Program Element of the Applied Sciences Program.

  5. A parsimonious data assimilation system for optimally integrating multi-sensor satellite observations over semi-arid areas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Land data assimilation systems are commonly tasked with merging remotely sensed surface soil moisture retrievals with information derived from a soil water balance model driven by observed rainfall. The performance of such systems can be degraded by the incorrect specification of parameters describi...

  6. Satellite Observations of Atmospheric Gravity Waves

    NASA Technical Reports Server (NTRS)

    Wu, D. L.; Waters, J. W.

    1995-01-01

    The Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite produced the first global maps of small-scale gravity wave variances in the middle atmosphere. Observations at 30-88 km altitudes show that the variances of 30-100 km horizontal scales are strongly correlated with surface topography and stratospheric jet streams. The several years of MLS data will provide a climatology of global gravity wave activity needed for modeling atmospheric circulations and mixing processes.

  7. Voyager 2 photopolarimeter observations of the Uranian satellites

    NASA Astrophysics Data System (ADS)

    Nelson, Robert M.; Buratti, Bonnie J.; Wallis, Brad D.; Lane, Arthur L.; West, Robert A.

    1987-12-01

    The authors report the ultraviolet (0.25 ?m) and infrared (0.75 ?m) geometric albedos, phase curves, and phase coefficients for the large Uranian satellites using full disk photometric observations obtained by the photopolarimeter subsystem during the Voyager 2 encounter with the Uranian system. The phase coefficients and phase curves of the Uranian satellites are consistent with surfaces that have a loosely packed regolith with a heavily cratered terrain. Ariel, Titania, and Oberon exhibit a reddening with increasing phase angle of observation. The authors do not observe this effect for Umbriel. They have determined preliminary phase integrals for Ariel, Umbriel, Titania, and Oberon, and they have used this information and the geometric albedos reported herein and previously reported by the Voyager imaging subsystem to derive Bond albedos for the satellites.

  8. Satellite-based observations of surface turbulent stress during severe weather

    E-print Network

    Satellite-based observations of surface turbulent stress during severe weather Mark A. Bourassa The environment of severe marine weather is harsh: in situ and satellite observations of surface turbulent of mesoscale atmospheric systems. Satellite remote sensing provides an alternative that is capable of capturing

  9. Students as Ground Observers for Satellite Cloud Retrieval Validation

    NASA Technical Reports Server (NTRS)

    Chambers, Lin H.; Costulis, P. Kay; Young, David F.; Rogerson, Tina M.

    2004-01-01

    The Students' Cloud Observations On-Line (S'COOL) Project was initiated in 1997 to obtain student observations of clouds coinciding with the overpass of the Clouds and the Earth's Radiant Energy System (CERES) instruments on NASA's Earth Observing System satellites. Over the past seven years we have accumulated more than 9,000 cases worldwide where student observations are available within 15 minutes of a CERES observation. This paper reports on comparisons between the student and satellite data as one facet of the validation of the CERES cloud retrievals. Available comparisons include cloud cover, cloud height, cloud layering, and cloud visual opacity. The large volume of comparisons allows some assessment of the impact of surface cover, such as snow and ice, reported by the students. The S'COOL observation database, accessible via the Internet at http://scool.larc.nasa.gov, contains over 32,000 student observations and is growing by over 700 observations each month. Some of these observations may be useful for assessment of other satellite cloud products. In particular, some observing sites have been making hourly observations of clouds during the school day to learn about the diurnal cycle of cloudiness.

  10. Observing Outer Planet Satellites (except Titan) with JWST: Science Justification and Observational Requirements

    E-print Network

    Keszthelyi, Laszlo; Stansberry, John; Sivaramakrishnan, Anand; Thatte, Deepashri; Gudipati, Murthy; Tsang, Constantine; Greenbaum, Alexandra; McGruder, Chima

    2015-01-01

    The James Webb Space Telescope (JWST) will allow observations with a unique combination of spectral, spatial, and temporal resolution for the study of outer planet satellites within our Solar System. We highlight the infrared spectroscopy of icy moons and temporal changes on geologically active satellites as two particularly valuable avenues of scientific inquiry. While some care must be taken to avoid saturation issues, JWST has observation modes that should provide excellent infrared data for such studies.

  11. Feasibility of tropical cyclone intensity estimation using satellite-borne radiometer measurements: An observing system simulation experiment

    E-print Network

    Sieron, Scott B.

    This study evaluates the potential of a proposed technique in using satellite-borne radiometer measurements and weather analyses to estimate the intensity of tropical cyclones. This theory shows that intensity is essentially ...

  12. Meteorological Satellites (METSAT) and Earth Observing System (EOS) Advanced Microwave Sounding Unit-A (AMSU-A) Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This Failure Modes and Effects Analysis (FMEA) is for the Advanced Microwave Sounding Unit-A (AMSU-A) instruments that are being designed and manufactured for the Meteorological Satellites Project (METSAT) and the Earth Observing System (EOS) integrated programs. The FMEA analyzes the design of the METSAT and EOS instruments as they currently exist. This FMEA is intended to identify METSAT and EOS failure modes and their effect on spacecraft-instrument and instrument-component interfaces. The prime objective of this FMEA is to identify potential catastrophic and critical failures so that susceptibility to the failures and their effects can be eliminated from the METSAT/EOS instruments.

  13. Satellite observations of transionospheric pulse pairs

    SciTech Connect

    Holden, D.N.; Munson, C.P.; Devenport, J.C.

    1995-04-15

    The BLACKBEARD payload aboard the ALEXIS satellite has been making broadband observations in the VHF band of the radio spectrum. Since November of 1993 several hundred unusual signals have been recorded. The peculiar nature of these bursts of radio noise is that they have a duration of approximately 10 {mu}sec, are typically 20 to 40 dB brighter than the average background, and occur in pairs separated by approximately 50 {mu}sec. The authors have dubbed these emissions TransIonospheric Pulse Pairs, or TIPP events. They do not know what the source of these emissions is, but the dispersion of these signals is consistent with an origin at or near the earth`s surface. The satellite field of view and time of day when TIPP events are generally detected are consistent with regions of thunderstorm activity such as south-central Africa or Indonesia. 4 refs., 5 figs.

  14. On the Cloud Observations in JAXA's Next Coming Satellite Missions

    NASA Technical Reports Server (NTRS)

    Nakajima, Takashi Y.; Nagao, Takashi M.; Letu, Husi; Ishida, Haruma; Suzuki, Kentaroh

    2012-01-01

    The use of JAXA's next generation satellites, the EarthCARE and the GCOM-C, for observing overall cloud systems on the Earth is discussed. The satellites will be launched in the middle of 2010-era and contribute for observing aerosols and clouds in terms of climate change, environment, weather forecasting, and cloud revolution process study. This paper describes the role of such satellites and how to use the observing data showing concepts and some sample viewgraphs. Synergistic use of sensors is a key of the study. Visible to infrared bands are used for cloudy and clear discriminating from passively obtained satellite images. Cloud properties such as the cloud optical thickness, the effective particle radii, and the cloud top temperature will be retrieved from visible to infrared wavelengths of imagers. Additionally, we are going to combine cloud properties obtained from passive imagers and radar reflectivities obtained from an active radar in order to improve our understanding of cloud evolution process. This is one of the new techniques of satellite data analysis in terms of cloud sciences in the next decade. Since the climate change and cloud process study have mutual beneficial relationship, a multispectral wide-swath imagers like the GCOM-C SGLI and a comprehensive observation package of cloud and aerosol like the EarthCARE are both necessary.

  15. A multipurpose satellite ejection system

    NASA Technical Reports Server (NTRS)

    Moore, Michael B.

    1987-01-01

    A design is presented for a pneumatic ejection system capable of ejecting a spin stabilized satellite from the cargo bay of space vehicles. This system was orginally designed for use on the Spacelab 6 shuttle mission, but is now being considered for use with expendable rockets for launching satellites. The ejection system was designed to launch a 150 lb satellite at an initial ejection velocity of 32 ft/sec with a spin rate of 30 rev/min. The ejection system consists of a pneumatic cylinder, satellite retaining mechanism, and bearing assembly to allow the satellite to rotate during the spin up phase. As the cylinder is pressurized rapidly causing movement of the actuation piston, the mechanism automatically releases the spinning satellite by retracting a pneumatic locking pin and three spring loaded holddown pins. When the piston reaches the end of its stroke, it encounters a crushable aluminum honeycomb shock absorber which decelerates the piston and retaining mechanism. The assembly is designed for multiple uses except for the crushable shock absorber and pyrotechnic valves. The advantage of the design is discussed and patent no. and date given.

  16. The data distribution satellite system

    NASA Technical Reports Server (NTRS)

    Bruno, Ronald C.; Weinberg, Aaron

    1991-01-01

    The Data Distributed Satellite (DDS) will be capable of providing the space research community with inexpensive and easy access to space payloads and space data. Furthermore, the DDS is shown to be a natural outgrowth of advances and evolution in both NASA's Space Network and commercial satellite communications. The roadmap and timescale for this evolution is described along with key demonstrations, proof-of-concept models, and required technology development that will support the projected system evolution toward the DDS.

  17. The development of the geosynchronous weather satellite system

    NASA Technical Reports Server (NTRS)

    Greaves, J. R.; Shenk, W. E.

    1985-01-01

    A brief history of the U.S. geosynchronous weather satellite program is presented. The introduction of multiparameter observation systems on the Geostationary Synchronous Environmental Satellite (GOES) is discussed, with emphasis given to the visible spin-scan radiometer (VISSR); Data Collection System (DCS); and the Space Environment Monitor (SEM). A synopsis of current measurement capabilities of the GOES satellites is given with respect to temperature and mositure parameters. Several examples of GOES satellite imagery are provided.

  18. NEOWISE: Observations of the Irregular Satellites of Jupiter and Saturn

    E-print Network

    Grav, Tommy; Mainzer, Amy K; Masiero, Joe R; Nugent, Carrie R; Cutri, Roc M; Sonnet, Sarah; Kramer, Emily

    2015-01-01

    We present thermal model fits for 11 Jovian and 3 Saturnian irregular satellites based on measurements from the WISE/NEOWISE dataset. Our fits confirm spacecraft-measured diameters for the objects with in situ observations (Himalia and Phoebe) and provide diameters and albedo for 12 previously unmeasured objects, 10 Jovian and 2 Saturnian irregular satellites. The best-fit thermal model beaming parameters are comparable to what is observed for other small bodies in the outer Solar System, while the visible, W1, and W2 albedos trace the taxonomic classifications previously established in the literature. Reflectance properties for the irregular satellites measured are similar to the Jovian Trojan and Hilda Populations, implying common origins.

  19. NEOWISE: Observations of the Irregular Satellites of Jupiter and Saturn

    NASA Astrophysics Data System (ADS)

    Grav, T.; Bauer, J. M.; Mainzer, A. K.; Masiero, J. R.; Nugent, C. R.; Cutri, R. M.; Sonnett, S.; Kramer, E.

    2015-08-01

    We present thermal model fits for 11 Jovian and 3 Saturnian irregular satellites based on measurements from the WISE/NEOWISE data set. Our fits confirm spacecraft-measured diameters for the objects with in situ observations (Himalia and Phoebe) and provide diameters and albedo for 12 previously unmeasured objects, 10 Jovian and 2 Saturnian irregular satellites. The best-fit thermal model beaming parameters are comparable to what is observed for other small bodies in the outer solar system, while the visible, W1, and W2 albedos trace the taxonomic classifications previously established in the literature. Reflectance properties for the irregular satellites measured are similar to the Jovian Trojan and Hilda Populations, implying common origins.

  20. Satellite Application for Disaster Management Information Systems

    NASA Astrophysics Data System (ADS)

    Okpanachi, George

    Abstract Satellites are becoming increasingly vital to modern day disaster management activities. Earth observation (EO) satellites provide images at various wavelengths that assist rapid-mapping in all phases of the disaster management cycle: mitigation of potential risks in a given area, preparedness for eventual disasters, immediate response to a disaster event, and the recovery/reconstruction efforts follo wing it. Global navigation satellite systems (GNSS) such as the Global Positioning System (GPS) assist all the phases by providing precise location and navigation data, helping manage land and infrastructures, and aiding rescue crews coordinate their search efforts. Effective disaster management is a complex problem, because it involves many parameters, which are usually not easy to measure and even identify: Analysis of current situation, planning, optimum resource management, coordination, controlling and monitoring current activities and making quick and correct decisions are only some of these parameters, whose complete list is very long. Disaster management information systems (DMIS) assist disaster management to analyse the situation better, make decisions and suggest further actions following the emergency plans. This requires not only fast and thorough processing and optimization abilities, but also real-time data provided to the DMIS. The need of DMIS for disaster’s real-time data can be satisfied by small satellites data utilization. Small satellites can provide up-to-data, plus a better media to transfer data. This paper suggests a rationale and a framework for utilization of small Satellite data by DMIS. DMIS should be used ‘’before’’, ‘’during’’ and ‘’after’’ the disasters. Data provided by the Small Satellites are almost crucial in any period of the disasters, because early warning can save lives, and satellite data may help to identify disasters before they occur. The paper also presents’ ‘when’’, ‘’where’’ and ‘’how’’ small satellite data should be used by DMIS.

  1. Middle atmosphere composition revealed by satellite observations

    NASA Technical Reports Server (NTRS)

    Russell, J. M., III; Solomon, S.; Mccormick, M. P.; Miller, A. J.; Barnett, J. J.; Jones, R. L.; Rusch, D. W.

    1986-01-01

    A series of plots that describe the state of the stratosphere and to some degree, the mesosphere as revealed by satellite observations are shown. The pertinent instrument features, spatial and temporal coverage, and details of accuracy and precision for the experiments providing the data were described. The main features of zonal mean cross sections and polar stereographic projections were noted and intercomparisons were discussed where a parameter was measured by more than one experiment. The main purpose was to collect the available data in one place and provide enough inforamation on limitations or cautions about the data so that they could be used in model comparisons and science studies.

  2. Middle atmosphere composition revealed by satellite observations

    SciTech Connect

    Russell, J.M. III; Solomon, S.; Mccormick, M.P.; Miller, A.J.; Barnett, J.J.; Jones, R.L.; Rusch, D.W.

    1986-09-01

    A series of plots that describe the state of the stratosphere and to some degree, the mesosphere as revealed by satellite observations are shown. The pertinent instrument features, spatial and temporal coverage, and details of accuracy and precision for the experiments providing the data were described. The main features of zonal mean cross sections and polar stereographic projections were noted and intercomparisons were discussed where a parameter was measured by more than one experiment. The main purpose was to collect the available data in one place and provide enough inforamation on limitations or cautions about the data so that they could be used in model comparisons and science studies.

  3. Meteorological Satellites (METSAT) and Earth Observing System (EOS) Advanced Microwave Sounding Unit-A (AMSU-A) Stress Analysis Report

    NASA Technical Reports Server (NTRS)

    Heffner, Robert

    1996-01-01

    Stress analysis of the primary structure of the Meteorological Satellites Project (METSAT) Advanced Microwave Sounding Units-A, A1 Module using static loads is presented. The structural margins of safety and natural frequency predictions for the METSAT design are reported.

  4. Odyssey personal communications satellite system

    NASA Technical Reports Server (NTRS)

    Spitzer, Christopher J.

    1993-01-01

    The spectacular growth of cellular telephone networks has proved the demand for personal communications. Large regions of the world are too sparsely populated to be economically served by terrestrial cellular communications. Since satellites are well suited to this application, TRW filed with the FCC on May 31, 1993 for the Odyssey construction permit. Odyssey will provide high quality wireless communication services worldwide from satellites. These services will include: voice, data, paging, and messaging. Odyssey will be an economical approach to providing communications. A constellation of 12 satellites will be orbited in three, 55 deg. inclined planes at an altitude of 10,354 km to provide continuous coverage of designated regions. Two satellites will be visible anywhere in the world at all times. This dual visibility leads to high line-of-sight elevation angles, minimizing obstructions by terrain, trees and buildings. Each satellite generates a multibeam antenna pattern that divides its coverage area into a set of contiguous cells. The communications system employs spread spectrum CDMA on both the uplinks and downlinks. This signaling method permits band sharing with other systems and applications. Signal processing is accomplished on the ground at the satellite's 'Gateway' stations. The 'bent pipe' transponders accommodates different regional standards, as well as signaling changes over time. The low power Odyssey handset will be cellular compatible. Multipath fade protection is provided in the handset.

  5. Satellites

    SciTech Connect

    Burns, J.A.; Matthews, M.S.

    1986-01-01

    The present work is based on a conference: Natural Satellites, Colloquium 77 of the IAU, held at Cornell University from July 5 to 9, 1983. Attention is given to the background and origins of satellites, protosatellite swarms, the tectonics of icy satellites, the physical characteristics of satellite surfaces, and the interactions of planetary magnetospheres with icy satellite surfaces. Other topics include the surface composition of natural satellites, the cratering of planetary satellites, the moon, Io, and Europa. Consideration is also given to Ganymede and Callisto, the satellites of Saturn, small satellites, satellites of Uranus and Neptune, and the Pluto-Charon system.

  6. Observations of the magnetosphere and ionosphere by Dynamics Explorer satellite. III - S-band receiving system for the DE-1

    NASA Astrophysics Data System (ADS)

    Kasai, Katsuyuki; Nishigaki, Takanori; Sawada, Fumitake; Koike, Kunimasa; Kawai, Eiji

    1987-12-01

    Telemetry operation of ISIS and ISS satellites was conducted at Kashima station, Japan, using VHF (136 MHz) and UHF (400 MHz) telemetry receivers with an 18-m-diameter antenna dish to receive S-band signals from the DE-1 which are fed into the 400 MHz telemetry receivers after frequency conversion. Some characteristics of the improved telemetry facilities and some results of S-band signals received from the DE-1 are reported.

  7. Advanced satellite communication system

    NASA Technical Reports Server (NTRS)

    Staples, Edward J.; Lie, Sen

    1992-01-01

    The objective of this research program was to develop an innovative advanced satellite receiver/demodulator utilizing surface acoustic wave (SAW) chirp transform processor and coherent BPSK demodulation. The algorithm of this SAW chirp Fourier transformer is of the Convolve - Multiply - Convolve (CMC) type, utilizing off-the-shelf reflective array compressor (RAC) chirp filters. This satellite receiver, if fully developed, was intended to be used as an on-board multichannel communications repeater. The Advanced Communications Receiver consists of four units: (1) CMC processor, (2) single sideband modulator, (3) demodulator, and (4) chirp waveform generator and individual channel processors. The input signal is composed of multiple user transmission frequencies operating independently from remotely located ground terminals. This signal is Fourier transformed by the CMC Processor into a unique time slot for each user frequency. The CMC processor is driven by a waveform generator through a single sideband (SSB) modulator. The output of the coherent demodulator is composed of positive and negative pulses, which are the envelopes of the chirp transform processor output. These pulses correspond to the data symbols. Following the demodulator, a logic circuit reconstructs the pulses into data, which are subsequently differentially decoded to form the transmitted data. The coherent demodulation and detection of BPSK signals derived from a CMC chirp transform processor were experimentally demonstrated and bit error rate (BER) testing was performed. To assess the feasibility of such advanced receiver, the results were compared with the theoretical analysis and plotted for an average BER as a function of signal-to-noise ratio. Another goal of this SBIR program was the development of a commercial product. The commercial product developed was an arbitrary waveform generator. The successful sales have begun with the delivery of the first arbitrary waveform generator.

  8. Use of Earth Observing Satellites for Operational Hazard Support

    NASA Astrophysics Data System (ADS)

    Wood, H. M.; Lauritson, L.

    The National Oceanic and Atmospheric Administration (NOAA) relies on Earth observing satellite data to carry out its operational mission to monitor, predict, and assess changes in the Earth's atmosphere, land, and oceans. NOAA's National Environmental Satellite, Data, and Information Service (NESDIS) uses satellite data to help lessen the impacts of natural and man-made disasters due to tropical cyclones, flash floods, heavy snowstorms, volcanic ash clouds (for aviation safety), sea ice (for shipping safety), and harmful algal blooms. Communications systems on NOAA satellites are used to support search and rescue and to relay data from data collection platforms to a variety of users. NOAA's Geostationary (GOES) and Polar (POES) Operational Environmental Satellites are used in conjunction with other satellites to support NOAA's operational mission. While NOAA's National Hurricane Center is responsible for predicting tropical cyclones affecting the U.S. mainland, NESDIS continuously monitors the tropics world wide, relaying valuable satellite interpretations of tropical systems strength and position to users throughout the world. Text messages are sent every six hours for tropical cyclones in the Western Pacific, South Pacific, and Indian Oceans. To support the monitoring, prediction, and assessment of flash floods and winter storms, NESDIS sends out text messages alerting U.S. weather forecast offices whenever NOAA satellite imagery indicates the occurrence of heavy rain or snow. NESDIS also produces a 24-hour rainfall composite graphic image covering those areas affected by heavy precipitation. The International Civil Aviation Organization (ICAO) and other aviation concerns recognized the need to keep aviators informed of volcanic hazards. To that end, nine Volcanic Ash Advisory Centers (VAAC's) were created to monitor volcanic ash plumes within their assigned airspace. NESDIS hosts one of the VAAC's. Although the NESDIS VAAC's primary responsibility is the continental U.S., Carribean, and adjacent oceans, it also tracks volcanic eruptions throughout the world. Text messages are produced along with graphic interpretations. This information, along with volcanic ash forecasts produced by NOAA's National Weather Service, is made available to U.S. Government and international agencies concerned with aviation, seismology, and climate analysis. Earth observing satellites help NESDIS to ensure safe navigation of ships through sea ice by measuring the extent, thickness, and age of ice as well as sea surface winds over the polar regions of the globe, coastal areas, and inland waterways. These satellites also help NESDIS to monitor U.S. coastal areas for dangerous algal blooms or other toxic effects to fish and sea mammals as well as monitoring floods and fires. Experimental fire products can help in the monitoring of fires and fire weather, as well as determining fire risk. Experimental soil moisture products support flood and drought monitoring. Flood extent and damage assessment for a variety of hazards can be determined from several satellites at varying spatial resolutions. The Search and Rescue Satellite Aided Tracking (SARSAT) system detects and locates persons in distress on land or water. NOAA satellites relay distress signals from emergency beacons through a network of ground stations to the U.S. Mission Control Center (USMCC). The USMCC processes the data and alerts the appropriate search and rescue authorities. SARSAT is part of the international Cospas-Sarsat Program. NOAA's GOES Data Collection (DCS) and Argos (jointly with the French space agency) POES Data Collection and Locations Systems transmit data collected from remote land and water based platforms and distributes the data to researchers, governmental and environmental organizations worldwide. The GOES DCS system allows near real time and frequent transmissions, e.g. hourly, over the Americas and much of the Atlantic and Eastern Pacific Oceans. ARGOS transmissions are less frequent, but global and provide the location of moving platforms such as animals and d

  9. Inferring Land Surface Model Parameters for the Assimilation of Satellite-Based L-Band Brightness Temperature Observations into a Soil Moisture Analysis System

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf H.; De Lannoy, Gabrielle J. M.

    2012-01-01

    The Soil Moisture and Ocean Salinity (SMOS) satellite mission provides global measurements of L-band brightness temperatures at horizontal and vertical polarization and a variety of incidence angles that are sensitive to moisture and temperature conditions in the top few centimeters of the soil. These L-band observations can therefore be assimilated into a land surface model to obtain surface and root zone soil moisture estimates. As part of the observation operator, such an assimilation system requires a radiative transfer model (RTM) that converts geophysical fields (including soil moisture and soil temperature) into modeled L-band brightness temperatures. At the global scale, the RTM parameters and the climatological soil moisture conditions are still poorly known. Using look-up tables from the literature to estimate the RTM parameters usually results in modeled L-band brightness temperatures that are strongly biased against the SMOS observations, with biases varying regionally and seasonally. Such biases must be addressed within the land data assimilation system. In this presentation, the estimation of the RTM parameters is discussed for the NASA GEOS-5 land data assimilation system, which is based on the ensemble Kalman filter (EnKF) and the Catchment land surface model. In the GEOS-5 land data assimilation system, soil moisture and brightness temperature biases are addressed in three stages. First, the global soil properties and soil hydraulic parameters that are used in the Catchment model were revised to minimize the bias in the modeled soil moisture, as verified against available in situ soil moisture measurements. Second, key parameters of the "tau-omega" RTM were calibrated prior to data assimilation using an objective function that minimizes the climatological differences between the modeled L-band brightness temperatures and the corresponding SMOS observations. Calibrated parameters include soil roughness parameters, vegetation structure parameters, and the single scattering albedo. After this climatological calibration, the modeling system can provide L-band brightness temperatures with a global mean absolute bias of less than 10K against SMOS observations, across multiple incidence angles and for horizontal and vertical polarization. Third, seasonal and regional variations in the residual biases are addressed by estimating the vegetation optical depth through state augmentation during the assimilation of the L-band brightness temperatures. This strategy, tested here with SMOS data, is part of the baseline approach for the Level 4 Surface and Root Zone Soil Moisture data product from the planned Soil Moisture Active Passive (SMAP) satellite mission.

  10. Satellite Observations of the Epic California Drought

    NASA Astrophysics Data System (ADS)

    Famiglietti, J. S.; Thomas, B. F.; Reager, J. T., II; Castle, S. L.; David, C. H.; Thomas, A. C.; Andreadis, K.; Argus, D. F.; Behrangi, A.; Farr, T.; Fisher, J. B.; Landerer, F. W.; Lo, M. H.; Molotch, N. P.; Painter, T. H.; Rodell, M.; Schimel, D.; Swenson, S. C.; Watkins, M. M.

    2014-12-01

    As California enters its third year of drought, questions of future water sustainability are inevitable. Snowpack, soil moisture, streamflow, reservoir and groundwater levels are at record lows. Mandatory water restrictions are being implemented, statewide fines for wasting water have been authorized, and billions of dollars and tens of thousands of jobs have been lost. Enhanced monitoring and modeling of the state's dwindling water supplies can help manage what remains while looking forward to a post-drought, sustainable water future. Here we demonstrate the role of satellite observations in comprehensive drought characterization and monitoring. In particular we highlight changing water supply, declining groundwater and reservoir levels, agricultural and urban stress. Potential contributions to water management will be discussed.

  11. Using the JPL Tropical Cyclone Information System to study the climatology of hurricane precipitation structure from 10 years of passive microwave satellite observations in the Atlantic

    NASA Astrophysics Data System (ADS)

    Hristova-Veleva, Svetla; Haddad, Ziad; Knosp, Brian; Lambrigtsen, Bjorn; Li, P. Peggy; Poulsen, William; Seo, Eun-Kyoung; Shen, Tsae-Pyng; Turk, Francis J.; Vu, Quoc

    2013-04-01

    In spite of recent improvements in hurricane track forecast accuracy, currently there are still many unanswered questions about the physical processes that determine hurricane genesis, and evolution. Furthermore, a significant amount of work remains to be done in validating and improving hurricane forecast models. None of this can be accomplished without a comprehensive set of multi-parameter observations that are relevant to both the large-scale and the storm-scale processes in the atmosphere and in the ocean. Despite the significant amount of satellite observations today, they are still underutilized in hurricane research and operations, due to complexity and volume. To facilitate hurricane research, we developed the JPL Tropical Cyclone Information System (TCIS) of multi-instrument satellite observations pertaining to: i) the thermodynamic and microphysical structure of the storms; ii) the air-sea interaction processes; iii) the larger-scale environment as depicted by the SST and the Total Precipitable Water of the environment (Hristova-Veleva et al., 2008, 2011). Our goal was to create a one-stop place to provide the researchers with an extensive set of observed hurricane data, and their graphical representation, organized in an easy way to determine when coincident observations from multiple instruments are available. In this study we use the 10+ years of passive microwave observations of Atlantic hurricanes to create composite structures that are segregated by hurricane category and by intensification rate. The use of composite structures provides a statistically robust framework (e.g. Rogers et al., 2012). We analyze the storm asymmetry as depicted by several factors - brightness temperatures and their derivatives such as a newly-develop Rain Indicator and a new convective/stratiform separation that is based on the value and the spatial variability of this Rain Indicator. The goal is to determine whether the storm morphology (in particular, the storm asymmetry or lack thereof) carries predictive skills regarding the potential for intensification. The presentation will describe the JPL TCIS and the results of our analysis of the passive microwave satellite observations of the Atlantic hurricanes. Refernces: Hristova-Veleva, S. M., C. Ao, Y. Chao, V. Dang, R. Fovell, M. Garay, Z. Haddad, B. Knosp, B. Lambrigtsen, P. P. Li, K. J. Park, W. Poulsen, H. Su, S. Tanelli, D. Vane, Q. A. Vu, J. Willis, D. L. Wu, 2008: "Using the JPL Tropical Cyclone Information System for Research and Applications", AMS 28th Hurricane and Tropical Meteorology Conference, Orlando, FL, 28Apr.-02May 2008 Hristova-Veleva, S. M., A. Chau, Z. Haddad, B. Knosp, B. Lambrigtsen, P. P. Li, E. Rodriguez, T. -. P. Shen, B. Stiles, H. Su, J. Turk, and Q. Vu, 2011: "Impact of microphysical parameterizations on the structure and intensity of simulated hurricanes: Using satellite data to determine the parameterizations that produce most realistic storms", 14th Conference on Mesoscale Processes, 1-4 August 2011, Los Angeles, California Rogers, R., S. Lorsolo, P. Reasor, J. Gamache, F. Marks, 2012: Multiscale Analysis of Tropical Cyclone Kinematic Structure from Airborne Doppler Radar Composites. Mon. Wea. Rev., 140, 77-99.

  12. Earth Observing System/Meteorological Satellite (EOS/METSAT). Advanced Microwave Sounding Unit-A (AMSU-A) Contamination Control Plan

    NASA Technical Reports Server (NTRS)

    Fay, M.

    1998-01-01

    This Contamination Control Plan is submitted in response the Contract Document requirements List (CDRL) 007 under contract NAS5-32314 for the Earth Observing System (EOS) Advanced Microwave Sounding Unit A (AMSU-A). In response to the CDRL instructions, this document defines the level of cleanliness and methods/procedures to be followed to achieve adequate cleanliness/contamination control, and defines the required approach to maintain cleanliness/contamination control through shipping, observatory integration, test, and flight. This plan is also applicable to the Meteorological Satellite (METSAT) except where requirements are identified as EOS-specific. This plan is based on two key factors: a. The EOS/METSAT AMSU-A Instruments are not highly contamination sensitive. b. Potential contamination of other EOS Instruments is a key concern as addressed in Section 9/0 of the Performance Assurance Requirements for EOS/METSAT Integrated Programs AMSU-A Instrument (MR) (NASA Specification S-480-79).

  13. The planned Chinese broadcasting satellite system

    NASA Astrophysics Data System (ADS)

    Xu, Z.; Zhang, Z.

    1985-12-01

    This paper outlines the necessity of establishing a broadcasting satellite system in China as the key to the realization of complete TV and radio coverage of China, and the popularization of education. It discusses in brief the composition of the planned China Broadcasting Satellite System (CBSS), its mission capacity, mode of transmission, satellite orbital position, beam configuration, PFD distribution, and in-orbit spare satellite. Particular attention is paid to the selection of the satellite frequency band.

  14. Applications systems verification and transfer project. Volume 3: Operational applications of satellite snow cover observations in California

    NASA Technical Reports Server (NTRS)

    Brown, A. J.; Hannaford, J. F.

    1981-01-01

    Five southern Sierra snowmelt basins and two northern Sierra-Southern Cascade snowmelt basins were used to evaluate the effect on operational water supply forecasting from satellite imagery. Manual photointerpretation techniques were used to obtain SCA and equivalent snow line for the years 1973 to 1979 for the seven test basins using LANDSAT imagery and GOES imagery. The use of SCA was tested operationally in 1977-79. Results indicate the addition of SCA improve the water supply forecasts during the snowmelt phase for these basins where there may be an unusual distribution of snowpack throughout the basin, or where there is a limited amount of real time data available. A high correlation to runoff was obtained when SCA was combined with snow water content data obtained from reporting snow sensors.

  15. Global Precipitation Analysis Using Satellite Observations

    NASA Technical Reports Server (NTRS)

    Adler, Robert F.; Huffman, George; Curtis, Scott; Bolvin, David; Nelkin, Eric

    2002-01-01

    Global precipitation analysis covering the last few decades and the impact of the new TRMM (Tropical Rainfall Measuring Mission) observations are reviewed in the context of weather and climate applications. All the data sets discussed are the result of mergers of information from multiple satellites and gauges, where available. The focus of the talk is on TRMM-based 3 hr. analyses that use TRMM to calibrate polar-orbit microwave observations from SSM/I (and other satellites) and geosynchronous IR observations and merges the various calibrated observations into a final, 3 hr. resolution map. This TRMM standard product will be available for the entire TRMM period (January 1998-present) at the end of 2002. A real-time version of this merged product is being produced and is available at 0.25 deg latitude-longitude resolution over the latitude range from 50 deg N-50 deg S. Examples will be shown, including its use in monitoring flood conditions and in relating weather-scale patterns to climate-scale patterns. The 3-hourly analysis is placed in the context of two research products of the World Climate Research Program's (WCRP/GEWEX) Global Precipitation Climatology Project (GPCP). The first is the 23 year, monthly, globally complete precipitation analysis that is used to explore global and regional variations and trends and is compared to the much shorter TRMM tropical data set. The GPCP data set shows no significant global trend in precipitation over the twenty years, unlike the positive trend in global surface temperatures over the past century. Regional trends are also analyzed. A trend pattern that is a combination of both El Nino and La Nina precipitation features is evident in the Goodyear data set. This pattern is related to an increase with time in the number of combined months of El Nino and La Nina during the 23 year period. Monthly anomalies of precipitation are related to ENSO variations with clear signals extending into middle and high latitudes of both hemispheres. Also shown is the GPCP daily, 1 deg latitude-longitude analysis, which is available from January 1997 to the present. Plans to incorporate the TRMM data and 3-hourly analysis into the GPCP products are outlined. The outcome should be an improved global analysis and climatology on monthly scales for the 23 year period and finer time scale analyses for more recent periods, including real-time 3-hourly (or finer) analyses over much of the globe.

  16. Satellite observations of ground water changes in New Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2002 NASA launched the Gravity Recovery and Climate Experiment (GRACE) satellite mission. GRACE consists of two satellites with a separation of about 200 km.  By accurately measuring the separation between the twin satellites, the differences in the gravity field can be determined. Monthly observ...

  17. The investigation of tethered satellite system dynamics

    NASA Technical Reports Server (NTRS)

    Lorenzini, E.

    1984-01-01

    Tethered satellite system (TSS) dynamics were studied. The dynamic response of the TSS during the entire stationkeeping phase for the first electrodynamic mission was investigated. An out of plane swing amplitude and the tether's bowing were observed. The dynamics of the slack tether was studied and computer code, SLACK2, was improved both in capabilities and computational speed. Speed hazard related to tether breakage or plasma contactor failure was examined. Preliminary values of the potential difference after the failure and of the drop of the electric field along the tether axis have been computed. The update of the satellite rotational dynamics model is initiated.

  18. Solar energy microclimate as determined from satellite observations

    NASA Technical Reports Server (NTRS)

    Vonder Haar, T. H.; Ellis, J. S.

    1975-01-01

    A method is presented for determining solar insolation at the earth's surface using satellite broadband visible radiance and cloud imagery data, along with conventional in situ measurements. Conventional measurements are used to both tune satellite measurements and to develop empirical relationships between satellite observations and surface solar insolation. Cloudiness is the primary modulator of sunshine. The satellite measurements as applied in this method consider cloudiness both explicitly and implicitly in determining surface solar insolation at space scales smaller than the conventional pyranometer network.

  19. Satellite Atmosphere and Io Torus Observations

    NASA Technical Reports Server (NTRS)

    Schneider, Nicholas

    2004-01-01

    NASA's Planetary Astronomy Program has supported a vigorous three-year program of groundbased observations and detailed analysis of the Jupiter/Io system. Our work focused on Io's escaping atmosphere and the plasma torus that it creates.

  20. Plasmaspheric ELF hiss observed by ISIS satellites

    NASA Astrophysics Data System (ADS)

    Ondoh, T.; Nakamura, Y.; Watanabe, S.; Aikyo, K.; Murakami, T.

    1982-11-01

    Characteristics of plasmaspheric ELF hiss in the topside ionosphere are statistically investigated using ELF/VLF electric field data of 231 ISIS passes received at Kashima station, Japan, from 1973-1977. ELF hiss is classified into two types, steady ELF hiss whose upper frequency limit is aproximately constant with latitude and ELF hiss whose upper frequency limit increases with increasing latitude. Spectral shape and bandwidth of ELF hiss obseved in the topside ionosphere are very similar to those of the plasmaspheric hiss or inner zone hiss observed by OGO-5 and OGO-6. The occurrence rate of steady ELF hiss is about 0.3 near the geomagnetic equator and decreses rapidly with increasing latitude around L = 3.37 percent of ELF hiss events occured during storms and 63 percent during quiet periods. 67 percent of 82 storm ELF hiss events occurred in the storm recovery phase. Electric field spectra of ELF hiss observed in mid- and low latitudes exhibit marked electric field weakness every ten seconds over one half of the satellite spin period.

  1. Solar power satellite system. [Patent application

    SciTech Connect

    Sarver, G.L. III

    1980-09-01

    A solar power satellite system is provided which includes a power satellite and at least one reflector satellite. The power satellite, which constitutes the great mass of the system, has a geosynchronous, gravity gradient stabilized orbit. The power satellite comprises a planar array of solar cells, with the plane of the satellite being oriented so as to be parallel with the plane of its orbit. An antenna or antennas mounted on the power satellite are powered by the solar cells and serve to transmit microwave energy back to earth. The shape and orbit of the reflector satellite are controlled so that solar radiation is focused by the reflector satellite onto the solar array of the power satellite. NASA

  2. Monitoring Lake and Reservoir Level: Satellite Observations, Modeling and Prediction

    NASA Astrophysics Data System (ADS)

    Ricko, M.; Birkett, C. M.; Adler, R. F.; Carton, J.

    2013-12-01

    Satellite measurements of lake and reservoir water levels complement in situ observations by providing stage information for un-gauged basins and by filling data gaps in gauge records. However, different satellite radar altimeter-derived continental water level products may differ significantly owing to choice of satellites and data processing methods. To explore the impacts of these differences, a direct comparison between three different altimeter-based surface water level estimates (USDA/NASA GRLM, LEGOS and ESA-DMU) will be presented and products validated with lake level gauge time series for lakes and reservoirs of a variety of sizes and conditions. The availability of satellite-based rainfall (i.e., TRMM and GPCP) and satellite-based lake/reservoir levels offers exciting opportunities to estimate and monitor the hydrologic properties of the lake systems. Here, a simple water balance model is utilized to relate net freshwater flux on a catchment basin to lake/reservoir level. Focused on tropical lakes and reservoirs it allows a comparison of the flux to altimetric lake level estimates. The combined use of model, satellite-based rainfall, evaporation information and reanalysis products, can be used to output water-level hindcasts and seasonal future forecasts. Such a tool is fundamental for understanding present-day and future variations in lake/reservoir levels and enabling a better understand of climatic variations on inter-annual to inter-decadal time-scales. New model-derived water level estimates of lakes and reservoirs, on regional to global scales, would assist communities with interests in climate studies focusing on extreme events, such as floods and droughts, and be important for water resources management.

  3. Mapping of satellite Earth observations using moving window block kriging

    NASA Astrophysics Data System (ADS)

    Tadi?, J. M.; Qiu, X.; Yadav, V.; Michalak, A. M.

    2015-10-01

    Global gridded maps (a.k.a. Level 3 products) of Earth system properties observed by satellites are central to understanding the spatiotemporal variability of these properties. They also typically serve either as inputs into biogeochemical models or as independent data for evaluating such models. Spatial binning is a common method for generating contiguous maps, but this approach results in a loss of information, especially when the measurement noise is low relative to the degree of spatiotemporal variability. Such "binned" fields typically also lack a quantitative measure of uncertainty. Geostatistical mapping has previously been shown to make higher spatiotemporal resolution maps possible, and also provides a measure uncertainty associated with the gridded products. This study proposes a flexible moving window block kriging method that can be used as a tool for creating high spatiotemporal resolution maps from satellite data. It relies only on the assumption that the observed physical quantity exhibits spatial correlation that can be inferred from the observations. The method has several innovations relative to previously applied methods: (1) it provides flexibility in the spatial resolution of the contiguous maps, (2) it is applicable for physical quantities with varying spatiotemporal coverage (i.e., density of measurements) by utilizing a more general and versatile data sampling approach, and (3) it provides rigorous assessments of the uncertainty associated with the gridded products. The method is demonstrated by creating Level 3 products from observations of column-integrated carbon dioxide (XCO2) from the GOSAT (Greenhouse Gases Observing Satellite) satellite, and solar induced fluorescence (SIF) from the GOME-2 (Global Ozone Monitoring Experiment-2) instrument.

  4. Satellite Systems around Galaxies in Hydrodynamic Simulations

    E-print Network

    Noam I Libeskind; Shaun Cole; Carlos S Frenk; Takashi Okamoto; Adrian Jenkins

    2006-07-11

    We investigate the properties of satellite galaxies formed in N-body/SPH simulations of galaxy formation in the $\\Lambda$CDM cosmology. The simulations include the main physical effects thought to be important in galaxy formation and, in several cases, produce realistic spiral discs. In total, a sample of 9 galaxies of luminosity comparable to the Milky Way was obtained. At magnitudes brighter than the resolution limit, $M_V=-12$, the luminosity function of the satellite galaxies in the simulations is in excellent agreement with data for the Local Group. The radial number density profile of the model satellites, as well as their gas fractions also match observations very well. In agreement with previous N-body studies, we find that the satellites tend to be distributed in highly flattened configurations whose major axis is aligned with the major axis of the (generally triaxial) dark halo. In 2 out of 3 systems with sufficiently large satellite populations, the satellite system is nearly perpendicular to the plane of the galactic disc, a configuration analogous to that observed in the Milk Way. The discs themselves are perpendicular to the minor axis of their host halos in the inner parts, and the correlation between the orientation of the galaxy and the shape of the halo persists even out to the virial radius. However, in one case the disc's minor axis ends up, at the virial radius, perpendicular to the minor axis of the halo. The angular momenta of the galaxies and their host halo tend to be well aligned.

  5. Small Aperture Telescope Observations of Co-located Geostationary Satellites

    NASA Astrophysics Data System (ADS)

    Scott, R.; Wallace, B.

    As geostationary orbit (GEO) continues to be populated, satellite operators are increasing usage of co-location techniques to maximize usage of fewer GEO longitude slots. Co-location is an orbital formation strategy where two or more geostationary satellites reside within one GEO stationkeeping box. The separation strategy used to prevent collision between the co-located satellites generally uses eccentricity (radial separation) and inclination (latitude separation) vector offsets. This causes the satellites to move in relative motion ellipses about each other as the relative longitude drift between the satellites is near zero. Typical separations between the satellites varies from 1 to 100 kilometers. When co-located satellites are observed by optical ground based space surveillance sensors the participants appear to be separated by a few minutes of arc or less in angular extent. Under certain viewing geometries, these satellites appear to visually conjunct even though the satellites are, in fact, well separated spatially. In situations where one of the co-located satellites is more optically reflective than the other, the reflected sunglint from the more reflective satellite can overwhelm the other. This less frequently encountered issue causes the less reflective satellite to be glint masked in the glare of the other. This paper focuses on space surveillance observations on co-located Canadian satellites using a small optical telescope operated by Defence R&D Canada - Ottawa. The two above mentioned problems (cross tagging and glint masking) are investigated and we quantify the results for Canadian operated geostationary satellites. The performance of two line element sets when making in-frame CCD image correlation between the co-located satellites is also examined. Relative visual magnitudes between the co-located members are also inspected and quantified to determine the susceptibility of automated telescopes to glint masking of co-located satellite members.

  6. Satellite observations of a monsoon depression

    NASA Technical Reports Server (NTRS)

    Warner, C.

    1984-01-01

    The exploration of a monsoon depression over Burma and the Bay of Bengal is discussed. Aircraft and satellite data were examined, with an emphasis on the Microwave Sounding Unit (MSU) aboard TIROS-N and the Scanning Multichannel Microwave Radiometer (SMMR) aboard Nimbus-7. The structure of the monsoon depression was found to be dominated by cumulus convection. The only systematic large scale behavior discerned was a propagation of the depression westward, and diurnal migration of contours of brightness temperature. These contours in the middle troposphere showed a gradient toward the north with the patterns migrating northward at night. From SMMR and dropwindsonde data, water vapor contents were found to be near 65 mm, increasing to more than 70 mm in the northeast Bay of Bengal. Cloud water contents reached about three mm. Rainfall rates exceeding 5.7 mm/h occurred over a small part of the storm area, while mean rainfall rates in areas of order 20,000 sq km reached approximately 0.5 mm/h. Measured MSU brightness temperatures were reconciled very well with dropwindsonde data and with airborne in situ observations of clouds (by photography) and hydrometeors (by radar). Diffuse scattering was determined to be important in computing brightness temperature.

  7. Outline of the survey on the development of earth observation satellites

    NASA Technical Reports Server (NTRS)

    1977-01-01

    An independent earth observation system with land and sea satellites to be developed by Japan is described. Visible and infrared radiometers, microwave radiometers, microwave scattermeters, synthetic aperture radar, and laser sensors are among the instrumentation discussed. Triaxial attitude control, basic technology common to sea and land observation satellites as well as land data analytical technology developed for U.S. LANDSAT data are reviewed.

  8. Gravity gradiometry from the Tethered Satellite System

    NASA Technical Reports Server (NTRS)

    Gullahorn, G. E.; Grossi, M. D.; Fuligni, F.

    1985-01-01

    Measurement of the gradient of the gravitational acceleration from a satellite platform is likely to provide the next improvement in knowledge of the earth's gravity field after the upcoming Geopotential Research Mission (GRM). Observations from the subsatellite of a Tethered Satellite System (TSS) would increase sensitivity and resolution due to the low altitude possible. However, the TSS is a dynamically 'noisy' system and would be perturbed by atmospheric drag fluctuations. The dynamic noise is being modeled in order to evaluate the feasibility of TSS gradiometry and to design methods of abating the error caused by this noise. The demonstration flights of the TSS will provide an opportunity to directly observe the dynamical environment and refine modeling techniques.

  9. Operational Applications of Satellite Snowcover Observations

    NASA Technical Reports Server (NTRS)

    Rango, A. (editor)

    1975-01-01

    LANDSAT and NOAA satellites data were used to study snow depth. These snow measurements were used to help forecast runoff and flooding. Many areas of California, Arizona, Colorado, and Wyoming were emphasized.

  10. Observations of the second Chinese satellite

    NASA Astrophysics Data System (ADS)

    Perry, G. E.

    1987-11-01

    Softwave transmissions on two frequencies were received following the launch of the second Chinese satellite. The 20.009 MHz transmission was powered by chemical batteries mounted on the final stage of the launch vehicle and ceased within one month of the launch. The 19.995 MHz transmission was powered by solar cells mounted on the satellie and continued until the satellite decayed after more than eight years in orbit. Analysis of this transmission reveals that active thermal control was employed.

  11. Astrometry in the Uranian system of satellites

    NASA Astrophysics Data System (ADS)

    Birlan, Mirel; Nedelcu, Dan Alin

    2008-09-01

    The predicted occultation between the satellites Miranda(UV) and Oberon(UIV) was observed on July 30, 2007 using SpeX/IRTF system and CODAM-Paris Observatory facility. Data analysis reveals that the predicted magnitude drop for this phenomenon was overestimated and we establish an upper limit of 0m.05 for the phenomenon, perhaps due to a non-lambertian limb scattering. The astrometry obtained from this run reveals good agreement with the LA06 numerical model.

  12. Studies of the major planet satellite systems

    NASA Technical Reports Server (NTRS)

    Frey, H.; Lowman, P. D.

    1974-01-01

    A summary is presented of the available data on the satellites of the major planets, including the currently most plausible models for several observed phenomena, for the planning of spacecraft missions to these objects. Some of the important questions likely to be solved by flyby and/or orbital missions to the giant planets are detailed, the importance of these studies to our understanding of the solar system as a whole is indicated.

  13. Satellite freeze forecast system: Executive summary

    NASA Technical Reports Server (NTRS)

    Martsolf, J. D. (principal investigator)

    1983-01-01

    A satellite-based temperature monitoring and prediction system consisting of a computer controlled acquisition, processing, and display system and the ten automated weather stations called by that computer was developed and transferred to the national weather service. This satellite freeze forecasting system (SFFS) acquires satellite data from either one of two sources, surface data from 10 sites, displays the observed data in the form of color-coded thermal maps and in tables of automated weather station temperatures, computes predicted thermal maps when requested and displays such maps either automatically or manually, archives the data acquired, and makes comparisons with historical data. Except for the last function, SFFS handles these tasks in a highly automated fashion if the user so directs. The predicted thermal maps are the result of two models, one a physical energy budget of the soil and atmosphere interface and the other a statistical relationship between the sites at which the physical model predicts temperatures and each of the pixels of the satellite thermal map.

  14. First satellite observations of lower tropospheric ammonia and methanol

    E-print Network

    First satellite observations of lower tropospheric ammonia and methanol Reinhard Beer,1 Mark W) and methanol (CH3OH), well above the normal background levels. This is the first time that these molecules have. Citation: Beer, R., et al. (2008), First satellite observations of lower tropospheric ammonia and methanol

  15. Tethered Satellite System Contingency Investigation Board

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The Tethered Satellite System (TSS-1) was launched aboard the Space Shuttle Atlantis (STS-46) on July 31, 1992. During the attempted on-orbit operations, the Tethered Satellite System failed to deploy successfully beyond 256 meters. The satellite was retrieved successfully and was returned on August 6, 1992. The National Aeronautics and Space Administration (NASA) Associate Administrator for Space Flight formed the Tethered Satellite System (TSS-1) Contingency Investigation Board on August 12, 1992. The TSS-1 Contingency Investigation Board was asked to review the anomalies which occurred, to determine the probable cause, and to recommend corrective measures to prevent recurrence. The board was supported by the TSS Systems Working group as identified in MSFC-TSS-11-90, 'Tethered Satellite System (TSS) Contingency Plan'. The board identified five anomalies for investigation: initial failure to retract the U2 umbilical; initial failure to flyaway; unplanned tether deployment stop at 179 meters; unplanned tether deployment stop at 256 meters; and failure to move tether in either direction at 224 meters. Initial observations of the returned flight hardware revealed evidence of mechanical interference by a bolt with the level wind mechanism travel as well as a helical shaped wrap of tether which indicated that the tether had been unwound from the reel beyond the travel by the level wind mechanism. Examination of the detailed mission events from flight data and mission logs related to the initial failure to flyaway and the failure to move in either direction at 224 meters, together with known preflight concerns regarding slack tether, focused the assessment of these anomalies on the upper tether control mechanism. After the second meeting, the board requested the working group to complete and validate a detailed integrated mission sequence to focus the fault tree analysis on a stuck U2 umbilical, level wind mechanical interference, and slack tether in upper tether control mechanism and to prepare a detailed plan for hardware inspection, test, and analysis including any appropriate hardware disassembly.

  16. Satellite voice broadcast system study, volume 2

    NASA Technical Reports Server (NTRS)

    Horstein, M.

    1985-01-01

    This study investigates the feasibility of providing Voice of America (VOA) broadcasts by satellite relay, rather than via terrestrial relay stations. Satellite voice broadcast systems are described for three different frequency bands: HF (26 MHz), VHF (68 MHz), and L-band (1.5 GHz). The geographical areas of interest at HF and L-band include all major land masses worldwide with the exception of the U.S., Canada, and Australia. Geostationary satellite configurations are considered for both frequency bands. In addition, a system of subsynchronous, circular satellites with an orbit period of 8 hours is developed for the HF band. VHF broadcasts, which are confined to the Soviet Union, are provied by a system of Molniya satellites. Satellites intended for HF or VHF broadcastinbg are extremely large and heavy. Satellite designs presented here are limited in size and weight to the capability of the STS/Centaur launch vehicle combination. Even so, at HF it would take 47 geostationary satellites or 20 satellites in 8-hour orbits to fully satisfy the voice-channel requirements of the broadcast schedule provided by VOA. On the other hand, three Molniya satellites suffice for the geographically restricted schedule at VHF. At L-band, only four geostationary satellites are needed to meet the requirements of the complete broadcast schedule. Moreover, these satellites are comparable in size and weight to current satellites designed for direct broadcast of video program material.

  17. STABILITY OF SATELLITES IN CLOSELY PACKED PLANETARY SYSTEMS

    SciTech Connect

    Payne, Matthew J.; Holman, Matthew J.; Deck, Katherine M.; Perets, Hagai B.

    2013-10-01

    We perform numerical integrations of four-body (star, planet, planet, satellite) systems to investigate the stability of satellites in planetary systems with tightly packed inner planets (STIPs). We find that the majority of closely spaced stable two-planet systems can stably support satellites across a range of parameter-space which is only slightly decreased compared to that seen for the single-planet case. In particular, circular prograde satellites remain stable out to ?0.4 R{sub H} (where R{sub H} is the Hill radius) as opposed to 0.5 R{sub H} in the single-planet case. A similarly small restriction in the stable parameter-space for retrograde satellites is observed, where planetary close approaches in the range 2.5-4.5 mutual Hill radii destabilize most satellites orbits only if a ? 0.65 R{sub H} . In very close planetary pairs (e.g., the 12:11 resonance) the addition of a satellite frequently destabilizes the entire system, causing extreme close approaches and the loss of satellites over a range of circumplanetary semi-major axes. The majority of systems investigated stably harbored satellites over a wide parameter-space, suggesting that STIPs can generally offer a dynamically stable home for satellites, albeit with a slightly smaller stable parameter-space than the single-planet case. As we demonstrate that multi-planet systems are not a priori poor candidates for hosting satellites, future measurements of satellite occurrence rates in multi-planet systems versus single-planet systems could be used to constrain either satellite formation or past periods of strong dynamical interaction between planets.

  18. Physical properties of the planets and satellites from radar observations

    NASA Technical Reports Server (NTRS)

    Pettengill, G. H.

    1978-01-01

    The radar cross section of a planetary target is defined as the area of an isotropic scatterer, normal to the illumination, that would yield the observed echo intensity, if it were placed at the target's location. Attention is given to the angular scattering law, surface imagery, and topography. The observational results are discussed, taking into account the moon and the inner planets, the asteroids, the Galilean satellites, and the rings of Saturn. It is pointed out that the reach of radar astronomy has maintained nearly an exponential growth over the past three decades, as the sensitivity of available radar systems has on average more than doubled each year. There are, however, limits to this growth set by the large costs required for a new generation of observing facilities. Only modest increases in radar system sensitivity are, therefore, expected for the next decade.

  19. The Earth Observing System

    NASA Technical Reports Server (NTRS)

    Shaffer, Lisa Robock

    1992-01-01

    The restructuring of the NASA Earth Observing System (EOS), designed to provide comprehensive long term observations from space of changes occurring on the Earth from natural and human causes in order to have a sound scientific basis for policy decisions on protection of the future, is reported. In response to several factors, the original program approved in the fiscal year 1991 budget was restructured and somewhat reduced in scope. The resulting program uses three different sized launch vehicles to put six different spacecraft in orbit in the first phase, followed by two replacement launches for each of five of the six satellites to maintain a long term observing capability to meet the needs of global climate change research and other science objectives. The EOS system, including the space observatories, the data and information system, and the interdisciplinary global change research effort, are approved and proceeding. Elements of EOS are already in place, such as the research investigations and initial data system capabilities. The flights of precursor satellite and Shuttle missions, the ongoing data analysis, and the evolutionary enhancements to the integrated Earth science data management capabilities are all important building blocks to the full EOS program.

  20. Co-ordination of satellite and data programs: The committee on earth observation satellites' approach

    NASA Astrophysics Data System (ADS)

    Embleton, B. J. J.; Kingwell, J.

    1997-01-01

    Every year, an average of eight new civilian remote sensing satellite missions are launched. Cumulatively, over 250 such missions, each with a cost equivalent in current value to between US 100 million to US 1000 million, have been sponsored by space agencies in perhaps two dozen countries. These missions produce data and information products which are vital for informed decision making all over the world, on matters relating to natural resource exploitation, health and safety, sustainable national development, infrastructure planning, and a host of other applications. By contributing to better scientific understanding of global changes in the atmosphere, land surface, oceans and ice caps, these silently orbiting sentinels in the sky make it possible for governments and industries to make wiser environmental policy decisions and support the economic development needs of humanity. The international Committee on Earth Observation Satellites (CEOS) is the premier world body for co-ordinating and planning civilian satellite missions for Earth observation. Through its technical working groups and special task teams, it endeavours to: • maximise the international benefits from Earth observation satellites; and • harmonise practice in calibration, validation, data management and information systems for Earth observation. CEOS encompasses not only space agencies (data providers), but also the great international scientific and operational programs which rely on Earth science data from space. The user organisations affiliated with CEOS, together with the mission operators, attempt to reconcile user needs with the complex set of considerations — including national interests, cost, schedule — which affect the undertaking of space missions. Without such an internationally co-ordinated consensual approach, there is a much greater risk of waste through duplication, and of missed opportunity, or through the absence of measurements of some vital physical or biological parameter by space borne sensors. Mechanisms used by CEOS to carry out these tasks are built upon consensus and understanding, as well as on technology transfer between countries. An area of recent heightened endeavour in CEOS has been to determine and address the special needs of developing countries in respect of Earth observation data. In the next several years, a new wave of Earth observation will break, as the private sector, revitalised with decommissioned military technology, brings exciting new capabilities to international remote sensing. With rapidly burgeoning markets in spatial information or geomatics, as well as the continuing thirst of science programs for spatial information, there is a challenge upon the international space community to reassess continually, the most expedient and socially constructive means of making available in a fair and open way, geographically-reference information obtained with space observation systems.

  1. Developing a global aeronautical satellite system

    NASA Technical Reports Server (NTRS)

    Dement, Donald K.

    1988-01-01

    Arinc, an airline industry-owned and operated company in the United States, has taken steps toward establishing a global aeronautical satellite communications system. Plans call for initiation of a thin-route data operation in 1989, upgrading to establish voice communications via shared spot-beam transponders carried on other satellites, and deploying a worldwide network using dedicated satellites by 1994.

  2. The Aerospace Corporation 2009 Communication Satellite Systems

    E-print Network

    Low, Steven H.

    © The Aerospace Corporation 2009 Communication Satellite Systems Trends and Network Aspects Paul://www.aero.org/ Lee Center, Caltech 13 April 2009 #12;22 Communication Satellites · Brief History by Decade · Trends: ­ Communication Satellites, fifth edition, by D. Martin, P. Anderson, L. Bartamian, Aerospace / AIAA Press, 2006

  3. Perl Tools for Automating Satellite Ground Systems

    NASA Technical Reports Server (NTRS)

    McLean, David; Haar, Therese; McDonald, James

    2000-01-01

    The freeware scripting language Pert offers many opportunities for automating satellite ground systems for new satellites as well as older, in situ systems. This paper describes a toolkit that has evolved from of the experiences gained by using Pert to automate the ground system for the Compton Gamma Ray Observatory (CGRO) and for automating some of the elements in the Earth Observing System Data and Operations System (EDOS) ground system at Goddard Space Flight Center (GSFC). CGRO is an older ground system that was forced to automate because of fund cuts. Three 8 hour shifts were cut back to one 8 hour shift, 7 days per week. EDOS supports a new mission called Terra, launched December 1999 that requires distribution and tracking of mission-critical reports throughout the world. Both of these ground systems use Pert scripts to process data and display it on the Internet as well as scripts to coordinate many of the other systems that make these ground systems work as a coherent whole. Another task called Automated Multimodal Trend Analysis System (AMTAS) is looking at technology for isolation and recovery of spacecraft problems. This effort has led to prototypes that seek to evaluate various tools and technology that meet at least some of the AMTAS goals. The tools, experiences, and lessons learned by implementing these systems are described here.

  4. Tethered satellite system dynamics and control

    NASA Technical Reports Server (NTRS)

    Musetti, B.; Cibrario, B.; Bussolino, L.; Bodley, C. S.; Flanders, H. A.; Mowery, D. K.; Tomlin, D. D.

    1990-01-01

    The first tethered satellite system, scheduled for launch in May 1991, is reviewed. The system dynamics, dynamics control, and dynamics simulations are discussed. Particular attention is given to in-plane and out-of-plane librations; tether oscillation modes; orbiter and sub-satellite dynamics; deployer control system; the sub-satellite attitude measurement and control system; the Aeritalia Dynamics Model; the Martin-Marietta and NASA-MSFC Dynamics Model; and simulation results.

  5. Assessment of Global Annual Atmospheric Energy Balance from Satellite Observations

    NASA Technical Reports Server (NTRS)

    Lin, Bing; Stackhouse, Paul; Minnis, Patrick; Wielicki, Bruce A.; Hu, Yongxiang; Sun, Wenbo; Fan, Tai-Fang (Alice); Hinkelman, Laura

    2008-01-01

    Global atmospheric energy balance is one of the fundamental processes for the earth's climate system. This study uses currently available satellite data sets of radiative energy at the top of atmosphere (TOA) and surface and latent and sensible heat over oceans for the year 2000 to assess the global annual energy budget. Over land, surface radiation data are used to constrain assimilated results and to force the radiation, turbulent heat, and heat storage into balance due to a lack of observation-based turbulent heat flux estimations. Global annual means of the TOA net radiation obtained from both direct measurements and calculations are close to zero. The net radiative energy fluxes into the surface and the surface latent heat transported into the atmosphere are about 113 and 86 Watts per square meter, respectively. The estimated atmospheric and surface heat imbalances are about -8 9 Watts per square meter, values that are within the uncertainties of surface radiation and sea surface turbulent flux estimates and likely systematic biases in the analyzed observations. The potential significant additional absorption of solar radiation within the atmosphere suggested by previous studies does not appear to be required to balance the energy budget the spurious heat imbalances in the current data are much smaller (about half) than those obtained previously and debated at about a decade ago. Progress in surface radiation and oceanic turbulent heat flux estimations from satellite measurements significantly reduces the bias errors in the observed global energy budgets of the climate system.

  6. Economics of satellite communications systems

    NASA Astrophysics Data System (ADS)

    Pritchard, Wilbur L.

    This paper is partly a tutorial, telling systematically how one goes about calculating the total annual costs of a satellite communications system, and partly the expression of some original ideas on the choice of parameters so as to minimize these costs. The calculation of costs can be divided into two broad categories. The first is technical and is concerned with estimating what particular equipment will cost and what will be the annual expense to maintain and operate it. One starts in the estimation of any new system by listing the principal items of equipment, such as satellites, earth stations of various sizes and functions, telemetry and tracking equipment and terrestrial interfaces, and then estimating how much each item will cost. Methods are presented for generating such estimates, based on a knowledge of the gross parameters, such as antenna size, coverage area, transmitter power and information rate. These parameters determine the system performance and it is usually possible, knowing them, to estimate the costs of the equipment rather well. Some formulae based on regression analyses are presented. Methods are then given for estimating closely related expenses, such as maintenance and operation, and then an approximate method is developed for estimating terrestrial interconnection costs. It is pointed out that in specific cases when tariff and geographical information are available, it is usually better to work with specific data, but nonetheless it is often desirable, especially in global system estimating, to approximate these interconnect costs without recourse to individual tariffs. The procedure results in a set of costs for the purchase of equipment and its maintenance, and a schedule of payments. Some payments will be incurred during the manufacture of the satellite and before any systems operation, but many will not be incurred until the system is no longer in use, e.g. incentives. In any case, with the methods presented in the first section, one arrives at a schedule of costs and payments for all the items and the years in which they will be incurred. The second category of costing problems is one of financing or engineering economics. All the costs are first "present valued" to some reference period using rates of return appropriate to the particular situation. One finally arrives at sets of annual costs which can be used as the basis for setting lease costs or revenue requirements and tariffs. The correspondence between methods using discounted rates of return and capital recovery formulae on one hand and those using various depreciation schedules, such as is typical of regulated industries on the other hand, is discussed. The remainder of the paper is devoted to discussing the relationship between critical parameters, such as replacement schedules, design lifetime, satellite power and Earth station antenna size, and the overall costs. It is shown that optima for these parameters may exist and can be calculated. In particular, the optimization of satellite replacement schedules to minimize the present value of total investment over a very long period is presented, along with simplified versions of the theory suitable for system planning. The choice of EIRP is also discussed and a procedure for choosing the value that minimizes the costs is shown.

  7. Antarctic cloud and surface properties: Satellite observations and climate implications

    NASA Astrophysics Data System (ADS)

    Berque, Joannes

    2004-12-01

    The radiative effect of clouds in the Antarctic, although small at the top of the atmosphere, is very large within the surface-atmosphere system, and influences a variety of climate processes on a global scale. Because field observations are difficult in the Antarctic interior, satellite observations may be especially valuable in this region; but the remote sensing of clouds and surface properties over the high ice sheets is problematic due to the lack of radiometric contrast between clouds and the snow. A radiative transfer model of the Antarctic snow-atmosphere system is developed, and a new method is proposed for the examination of the problem of cloud properties retrieval from multi-spectral measurements. Key limitations are identified, and a method is developed to overcome them. Using data from the Advanced Very High Resolution Radiometer (AVHRR) onboard National Oceanic and Atmospheric Agency (NOAA) polar orbiters, snow grain size is retrieved over the course of a summer. Significant variability is observed, and it appears related to major precipitation events. A radiative transfer model and a single-column model are used to evaluate the impact of this variability on the Antarctic plateau. The range of observed grain size induces changes of up to 30 Wm-2 on the absorption of shortwave radiation in both models. Cloud properties are then retrieved in summertime imagery of the South Pole. Comparison of model to observations over a wide range of cloud optical depths suggests that this method allows the meaningful interpretation of AVHRR radiances in terms of cloud properties over the Antarctic plateau. The radiative effect of clouds at the top of the atmosphere is evaluated over the South Pole with ground-based lidar observations and data from Clouds and the Earth Radiant Energy System (CERES) onboard NASA's Terra satellite. In accord with previous work, results indicate that the shortwave and net effect are one of cooling throughout the year, while the longwave effect is one of cooling in winter and slight warming in summer.

  8. Global assessment of ocean carbon export by combining satellite observations

    E-print Network

    Siegel, David A.

    Global assessment of ocean carbon export by combining satellite observations and food-web models D Studies, University of Tasmania, Hobart, Tasmania, Australia Abstract The export of organic carbon from cycle. Here we introduce a mechanistic assessment of the global ocean carbon export using satellite

  9. Satellite Observed Changes in the Arctic

    NASA Technical Reports Server (NTRS)

    Comiso, Josefino C.; Parkinson, Claire L.

    2004-01-01

    The Arctic is currently considered an area in transformation. Glaciers have been retreating, permafrost has been diminishing, snow covered areas have been decreasing, and sea ice and ice sheets have been thinning. This paper provides an overview of the unique role that satellite sensors have contributed in the detection of changes in the Arctic and demonstrates that many of the changes are not just local but a pan-Arctic phenomenon. Changes from the upper atmosphere to the surface are discussed and it is apparent that the magnitude of the trends tends to vary from region to region and from season to season. Previous reports of a warming Arctic and a retreating perennial ice cover have also been updated, and results show that changes are ongoing. Feedback effects that can lead to amplification of the signals and the role of satellite data in enhancing global circulation models are also discussed.

  10. The Nimbus satellites - Pioneering earth observers

    NASA Technical Reports Server (NTRS)

    White, Carolynne

    1990-01-01

    The many scientific achievements of the Nimbus series of seven satellites for low-altitude atmospheric research and global weather surveillance are reviewed. The series provides information on fishery resources, weather modeling, atmospheric pollution monitoring, earth's radiation budget, ozone monitoring, ocean dynamics, and the effects of cloudiness. Data produced by the forty-eight instruments and sensors flown on the satellites are applied in the fields of oceanography, hydrology, geology, geomorphology, geography, cartography, agriculture and meteorology. The instruments include the Coastal Zone Color Scanner (which depicts phytoplankton concentrations in coastal areas), the Scanning Multichannel Microwave Radiometer (which measures sea-surface temperatures and sea-surface wind-speed), and the Total Ozone Mapping Spectrometer (which provides information on total amounts of ozone in the earth's atmosphere).

  11. Satellite Atmosphere and Io Torus Observations

    NASA Technical Reports Server (NTRS)

    Schneider, Nicholas M.

    2000-01-01

    Io is the most volcanically active body in the solar system, and it is embedded deep within the strongest magnetosphere of any planet. This combination of circumstances leads to a host of scientifically compelling phenomena, including (1) an atmosphere out of proportion with such a small object, (2) a correspondingly large atmospheric escape rate, (3) a ring of dense plasma locked in a feedback loop with the atmosphere, and (4) a host of Io-induced emissions from radio bursts to UV auroral spots on Jupiter. This proposal seeks to continue our investigation into the physics connecting these phenomena, with emphasis on Io's atmosphere and plasma torus. The physical processes are clearly of interest for Io, and also other places in the solar system where they are important but not readily observable.

  12. VLF line radiation observed by satellite

    NASA Astrophysics Data System (ADS)

    Rodger, Craig J.; Thomson, Neil R.; Dowden, Richard L.

    1995-04-01

    VLF line radiation recieved by the ISIS 1 and 2 satellites over New Zealand is found to fall into two distinct classes. The first of these consists of magnetospheric lines (MLs) which are characterized by a broadband appearance and by frequency drifts of a few tens of hertz per minute, similar to those reported elsewhere. Both their initial frequencies and their frequency spacings were, however, found to be esentially random rather than multiples of 50 or 60 HZ. The hourly variation in ML occurrence showed no correlation with electric load in possible electric mainstream sources. No clear decrease in occurrence on weekends was evident. The first satellite survey with significant numbers of MLs found no evidence of a relationship with power line harmonics. The second class of satellite-received VLF lines consisted of tram lines (TLs) which are characterized by their very narrow bandwidth and zero frequency drift. TLs appear to lie close to harmonics of 50 or 60 HZ. An example of this class is presented.

  13. Automatic satellite tracking system for the NASA Satellite Photometric Observatory

    NASA Technical Reports Server (NTRS)

    Mucklow, Glenn H.

    1980-01-01

    The development of an Automatic TV Tracking System for NASA's mobile 61 cm aperture Satellite Photometric Observatory is described. The analysis techniques used to match the FOV and resolutions to changing seeing conditions are covered in details. Theoretical reasons for such matching of general interest are discussed. It is shown that the energy density in a satellite image is 11 times greater during good seeing conditions than during typical seeing conditions. The Z7987 image tube is shown to be able to detect 16th magnitude objects under ideal seeing conditions using only 8 percent of the light collected by the main telescope. Experimental results show that the SPO equipped with a Z7987 camera can track a satellite at any orbital velocity with less than 0.14 mr accuracy using the DBA Series 606 TV Tracker. The manual system used prior to the installation of the Automatic TV Tracking System could maintain track at 1.1 mr accuracy for comparison.

  14. Retrieval of Non-Spherical Dust Aerosol Properties from Satellite Observations 

    E-print Network

    Huang, Xin

    2013-08-01

    An accurate and generalized global retrieval algorithm from satellite observations is a prerequisite to understand the radiative effect of atmospheric aerosols on the climate system. Current operational aerosol retrieval ...

  15. Assimilation of GOES satellite-based convective initiation and cloud growth observations into the Rapid Refresh and HRRR systems to improve aviation forecast guidance

    NASA Astrophysics Data System (ADS)

    Mecikalski, John; Smith, Tracy; Weygandt, Stephen

    2014-05-01

    Latent heating profiles derived from GOES satellite-based cloud-top cooling rates are being assimilated into a retrospective version of the Rapid Refresh system (RAP) being run at the Global Systems Division. Assimilation of these data may help reduce the time lag for convection initiation (CI) in both the RAP model forecasts and in 3-km High Resolution Rapid Refresh (HRRR) model runs that are initialized off of the RAP model grids. These data may also improve both the location and organization of developing convective storm clusters, especially in the nested HRRR runs. These types of improvements are critical for providing better convective storm guidance around busy hub airports and aviation corridor routes, especially in the highly congested Ohio Valley - Northeast - Mid-Atlantic region. Additional work is focusing on assimilating GOES-R CI algorithm cloud-top cooling-based latent heating profiles directly into the HRRR model. Because of the small-scale nature of the convective phenomena depicted in the cloud-top cooling rate data (on the order of 1-4 km scale), direct assimilation of these data in the HRRR may be more effective than assimilation in the RAP. The RAP is an hourly assimilation system developed at NOAA/ESRL and was implemented at NCEP as a NOAA operational model in May 2012. The 3-km HRRR runs hourly out to 15 hours as a nest within the ESRL real-time experimental RAP. The RAP and HRRR both use the WRF ARW model core, and the Gridpoint Statistical Interpolation (GSI) is used within an hourly cycle to assimilate a wide variety of observations (including radar data) to initialize the RAP. Within this modeling framework, the cloud-top cooling rate-based latent heating profiles are applied as prescribed heating during the diabatic forward model integration part of the RAP digital filter initialization (DFI). No digital filtering is applied on the 3-km HRRR grid, but similar forward model integration with prescribed heating is used to assimilate information from radar reflectivity, lightning flash density and the satellite based cloud-top cooling rate data. In the current HRRR configuration, 4 15-min cycles of latent heating are applied during a pre-forecast hour of integration. This is followed by a final application of GSI at 3-km to fit the latest conventional observation data. At the conference, results from a 5-day retrospective period (July 5-10, 2012) will be shown, focusing on assessment of data impact for both the RAP and HRRR, as well as the sensitivity to various assimilation parameters, including assumed heating strength. Emphasis will be given to documenting the forecast impacts for aviation applications in the Eastern U.S.

  16. China's future domestic satellite communications systems

    NASA Astrophysics Data System (ADS)

    Liang, G.; Yaokun, Y.

    1985-01-01

    Some ideas about China's future domestic satellite communications system are discussed. The following objectives are considered in the design of the new domestic satellite communications system: (1) the satellite communications system should link the entire country and form a unified national network with the existing ground communications system, (2) based on the geographic situation, the satellite communications system should be primarily small and scattered in the west, and large and concentrated in the east, (3) the Telephone business should be the primary business of the satellite communications system. It should also be capable of transmitting television, telegram, data, facsimile, and broadcasting, (4) the communications system should be primarily designed as a single jump system. It should not exceed two jumps, and (5) the parameters of the communications system should be in agreement with CCIR and CCITT recommendations.

  17. Characterizing user requirements for future land observing satellites

    NASA Technical Reports Server (NTRS)

    Barker, J. L.; Cressy, P. J.; Schnetzler, C. C.; Salomonson, V. V.

    1981-01-01

    The objective procedure was developed for identifying probable sensor and mission characteristics for an operational satellite land observing system. Requirements were systematically compiled, quantified and scored by type of use, from surveys of federal, state, local and private communities. Incremental percent increases in expected value of data were estimated for critical system improvements. Comparisons with costs permitted selection of a probable sensor system, from a set of 11 options, with the following characteristics: 30 meter spatial resolution in 5 bands and 15 meters in 1 band, spectral bands nominally at Thematic Mapper (TM) bands 1 through 6 positions, and 2 day data turn around for receipt of imagery. Improvements are suggested for both the form of questions and the procedures for analysis of future surveys in order to provide a more quantitatively precise definition of sensor and mission requirements.

  18. Research on Complicated Imaging Condition of GEO Optical High Resolution Earth Observing Satellite

    NASA Astrophysics Data System (ADS)

    Guo, Linghua

    2012-07-01

    The requirement for high time and space resolution of optical remote sensing satellite in disaster, land resources, environment, marine monitoring and meteorology observation, etc is getting urgent and strict. For that reason, a remote sensing satellite system solely located in MEO or LEO cannot operate continuous observation and Surveillance. GEO optical high resolution earth observing satellite in the other hand can keep the mesoscale and microscale target under continuous surveillance by controlling line of sight(LOS), and can provide imaging observation of an extensive region in a short time. The advantages of GEO satellite such as real-time observation of the mesoscale and microscale target, rapid response of key events, have been recognized by lots of countries and become a new trend of remote sensing satellite. As many advantages as the GEO remote sensing satellite has, its imaging condition is more complicated. Many new characteristics of imaging observation and imaging quality need to be discussed. We analyze each factor in the remote sensing link, using theoretical analysis and modeling simulation to get coefficient of each factor to represent its effect on imaging system. Such research achievements can provide reference for satellite mission analysis and system design.

  19. The Use of a Parallel Data Processing and Error Analysis System (DPEAS) for the Observational Exploration of Complex Multi-Satellite Non-Gaussian Data Assimilation Algorithms

    NASA Astrophysics Data System (ADS)

    Jones, A. S.; Fletcher, S. J.; Kidder, S. Q.; Forsythe, J. M.

    2012-12-01

    The CSU/NOAA Data Processing and Error Analysis System (DPEAS) was created to merge, or blend, multiple satellite and model data sets within a single consistent framework. DPEAS is designed to be used at both research and operational facilities to facilitate Research-to-Operations technology transfers. The system supports massive parallelization via grid computing technologies, and hosts data fusion techniques for transference to 24/7 operations in a low cost computational environment. In this work, we highlight the data assimilation and data fusion methodologies of the DPEAS framework that facilitates new and complex multi-satellite non-Gaussian data assimilation algorithm developments. DPEAS is in current operational use at NOAA/NESDIS Office of Satellite and Product Operations (OSPO) and performs multi-product data fusion of global "blended" Total Precipitable Water (bTPW) and blended Rainfall Rate (bRR). In this work we highlight: 1) the current dynamic inter-satellite calibration processing performed within the DPEAS data fusion and error analysis, 2) as well as our DPEAS development plans for future blended products (AMSR-2 and Megha-Tropiques), and 3) layered TPW products using the NASA AIRS data for National Weather Service forecaster use via the NASA SPoRT facility at Huntsville, AL. We also discuss new system additions for cloud verification and prediction activities in collaboration with the National Center for Atmospheric Research (NCAR), and planned use with the USAF Air Force Weather Agency's (AFWA) global Cloud Depiction and Forecast System (CDFS) facilities. Scientifically, we focus on the data fusion of atmospheric and land surface product information, including global cloud and water vapor data sets, soil moisture data, and specialized land surface products. The data fusion methods include the use of 1DVAR data assimilation for satellite sounding data sets, and numerous real-time statistical analysis methods. Our new development activities to extend the current 1DVAR algorithm to use and test a new non-Gaussian data assimilation method are presented. This research was supported by multiple grants from the NOAA/NESDIS Product System Development and Implementation (PSDI) program, a NASA ROSES grant, and a grant by the Air Force Weather Agency (AFWA) to the DoD Center for Geosciences / Atmospheric Research (CG/AR) at Colorado State University, as well as a subcontract from the National Center for Atmospheric Research (NCAR) to CSU.

  20. Integration of mobile satellite and cellular systems

    NASA Technical Reports Server (NTRS)

    Drucker, Elliott H.; Estabrook, Polly; Pinck, Deborah; Ekroot, Laura

    1993-01-01

    By integrating the ground based infrastructure component of a mobile satellite system with the infrastructure systems of terrestrial 800 MHz cellular service providers, a seamless network of universal coverage can be established. Users equipped for both cellular and satellite service can take advantage of a number of features made possible by such integration, including seamless handoff and universal roaming. To provide maximum benefit at lowest posible cost, the means by which these systems are integrated must be carefully considered. Mobile satellite hub stations must be configured to efficiently interface with cellular Mobile Telephone Switching Offices (MTSO's), and cost effective mobile units that provide both cellular and satellite capability must be developed.

  1. A study of satellite emergency locator systems

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Satellite emergency locator systems were studied. The objective of the study was to determine the feasibility and hardware requirements for satellite systems capable of identifying and locating the position emergency locator transmitters and emergency position indicating radio beacons. Both geosynchronous and near-polar-orbiting satellites were considered. One of the most important aspects of the study was to minimize the cost of the hardware required.

  2. Applications systems verification and transfer project. Volume 6: Operational applications of satellite snow-cover observations NOAA/NESS support study

    NASA Technical Reports Server (NTRS)

    Schneider, S. R.

    1981-01-01

    Geostationary and polar orbiting satellite data from the National Oceanic and Atmospheric Administration were used to operationally provide field hydrologists with basin snowcover percentages for inclusion in runoff models. Data reduction is accomplished thru the use of optical rectification devices and electronic color density slicers. Over two thousand satellite-derived snow maps covering 30 different basins in the western United States were provided to users. Plans for improving snowmapping techniques on computer interactive systems and by all-digital analysis are presented. A description of the newest generation of NOAA polar orbiters, TIROS-N, and its potential for snowmapping is reviewed. Snowcover percentages for all basins determined between November 1974 and July 1978 are presented in tabular format.

  3. Satellite observations of Magnetospheric Line Radiation

    NASA Astrophysics Data System (ADS)

    Nemec, F.; Santolik, O.; Parrot, M.; Berthelier, J. J.

    2006-12-01

    Results of a systematic survey of Magnetospheric Line Radiation (MLR) observed by the DEMETER spacecraft (launched in June, 2004, inclination ~98 degrees, altitude ~700 km, designed to study electromagnetic phenomena connected with seismic or man-made activity) are presented. In order to obtain a statistically significant data set, an automatic identification procedure of possible MLR events has been developed and applied to all the data measured since the beginning of the mission. We show that there are two principally different classes of events: 1) Events with frequency spacing of 50/100 or 60/120 Hz (Power Line Harmonic Radiation, PLHR). The artificial origin of these events from power systems is demonstrated by tracing magnetic field lines to the possible regions of generation. Effects of several parameters (peak intensity, magnetic local time, Kp index, number of lines, frequency) are studied. 2) Events with frequency spacing different from frequencies of power systems ("real-MLR"). Since these emissions usually occur at lower frequencies, it is in many cases possible to use ELF data, where all the 6 components of the electromagnetic field are measured during the Burst mode. We perform a detailed analysis of these events, classifying them into several groups. There is no evidence for their artificial origin.

  4. Satellite Observation Highlights of the 2010 Russian Wildfires

    NASA Technical Reports Server (NTRS)

    Witte, Jacquelyn C.; Douglass, Anne R.; Duncan, Bryan N.; daSilva, Arlindo; Torres, Omar

    2010-01-01

    From late-July through mid-August 2010, wildfires raged in western Russia. The resulting thick smoke and biomass burning products were transported over the highly populated Moscow city and surrounding regions, seriously impairing visibility and affecting human health. We demonstrate the uniqueness of the 2010 Russian wildfires by using satellite observations from NASA's Earth Observing System (EOS) platforms. Over Moscow and the region of major fire activity to the southeast, we calculate unprecedented increases in the MODIS fire count record of 178 %, an order of magnitude increase in the MODIS fire radiative power (308%) and OMI absorbing aerosols (255%), and a 58% increase in AIRS total carbon monoxide (CO). The exceptionally high levels of CO are shown to be of comparable strength to the 2006 El Nino wildfires over Indonesia. Both events record CO values exceeding 30x10(exp 7) molec/ square cm.

  5. ECS - The European Communication Satellite system

    NASA Astrophysics Data System (ADS)

    Wooster, C. B.

    1981-09-01

    The evolution of the European Communication Satellite system (ECS) is traced from feasibility studies in 1970 to the development and launch in 1978 of the Orbital Test Satellite (OTS) by the European Space Agency to prove the new satellite and radio transmission technology being used on ECS. This was followed by the establishment of 'Interim EUTELSAT' in 1979 as the organization to operate ECS. The satellite, which operates at 11/14 GHz, covers all the capitals in Europe via three spot beam antennas, supplemented by a 'Eurobeam' regional coverage antenna which extends the range to cover all of Europe and the Mediterranean basin. Telephony channels are transmitted digitally using time division multiple access (TDMA) with digital speech interpolation (DSI) to optimize satellite capacity. Television transmission is by analog FM over the Eurobeam antenna to North African as well as European capitals. System implications of TDMA operation are discussed, and the EUTELSAT policy for Special Services or satellite business systems is discussed.

  6. Observing tectonic plate motions and deformations from satellite laser ranging

    NASA Technical Reports Server (NTRS)

    Christodoulidis, D. C.; Smith, D. E.; Kolenkiewicz, R.; Klosko, S. M.; Torrence, M. H.

    1985-01-01

    The scope of geodesy has been greatly affected by the advent of artificial near-earth satellites. The present paper provides a description of the results obtained from the reduction of data collected with the aid of satellite laser ranging. It is pointed out that dynamic reduction of satellite laser ranging (SLR) data provides very precise positions in three dimensions for the laser tracking network. The vertical components of the stations, through the tracking geometry provided by the global network and the accurate knowledge of orbital dynamics, are uniquely related to the center of mass of the earth. Attention is given to the observations, the methodologies for reducing satellite observations to estimate station positions, Lageos-observed tectonic plate motions, an improved temporal resolution of SLR plate motions, and the SLR vertical datum.

  7. Providing satellite systems for the national weather satellite services.

    NASA Technical Reports Server (NTRS)

    Stroud, W. G.; Press, H.; Stampfl, R. A.

    1973-01-01

    Discussion of cooperative arrangements and agreements among NASA, the Department of Commerce, and other governmental agencies in developing and operating meteorological satellite systems. The development of present interagency agreements and their conditions are discussed along with differences from the usual NASA program introduced by the supplier-client relationship between NASA and NOAA (National Oceanic and Atmospheric Administration).

  8. Autonomous satellite navigation methods using the Global Positioning Satellite System

    NASA Technical Reports Server (NTRS)

    Murata, M.; Tapley, B. D.; Schutz, B. E.

    1982-01-01

    This investigation considers the problem of autonomous satellite navigation using the NAVSTAR Global Positioning System (GPS). The major topics covered include the design, implementation, and validation of onboard navigation filter algorithms by means of computer simulations. The primary errors that the navigation filter design must minimize are computational effects and modeling inaccuracies due to limited capability of the onboard computer. The minimization of the effect of these errors is attained by applying the sequential extended Kalman filter using a factored covariance implementation with Q-matrix or dynamical model compensations. Peformance evaluation of the navigation filter design is carried out using both the CDC Cyber 170/750 computer and the PDP-11/60 computer. The results are obtained assuming the Phase I GPS constellation, consisting of six satellites, and a Landsat-D type spacecraft as the model for the user satellite orbit.

  9. International Collaboration in Satellite Observations for Disaster Management

    NASA Technical Reports Server (NTRS)

    Duda, Kenneth A.; Abrams, Michael

    2012-01-01

    When lives are threatened or lost due to catastrophic disasters, and when massive financial impacts are experienced, international emergency response teams rapidly mobilize to provide urgently required support. Satellite observations of affected areas often provide essential insight into the magnitude and details of the impacts. The large cost and high complexity of developing and operating satellite flight and ground systems encourages international collaboration in acquiring imagery for such significant global events in order to speed delivery of critical information to help those affected, and optimize spectral, spatial, and temporal coverage of the areas of interest. The International Charter-Space and Major Disasters was established to enable such collaboration in sensor tasking during times of crisis and is often activated in response to calls for assistance from authorized users. Insight is provided from a U.S. perspective into sensor support for Charter activations and other disaster events through a description of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), which has been used to support emergency situations for over a decade through its expedited tasking and near real-time data delivery capabilities. Examples of successes achieved and challenges encountered in international collaboration to develop related systems and fulfill tasking requests suggest operational considerations for new missions as well as areas for future enhancements.

  10. US EPA: A USER AGENCY PERSPECTIVE ON POLAR SATELLITE OBSERVATIONS

    EPA Science Inventory

    The Agency uses satellite sensor observations in its work on measuring, monitoring and modeling the environment and human health. It generates observations in collaboration with states, local and regional governments, tribes and others, and is a consumer of observations from a v...

  11. Satellite observation of dehydration in the Arctic Polar stratosphere

    E-print Network

    Pan, Laura

    Satellite observation of dehydration in the Arctic Polar stratosphere L. L. Pan,1 W. J. Randel,1 H 2002. [1] We report the first space-borne observation of dehydration in the Arctic polar stratosphere Stratospheric Cloud (PSC) events. Furthermore, simultaneous observations of HNO3 and H2O show that the gas phase

  12. Satellite multiple access systems for mobile communication

    NASA Technical Reports Server (NTRS)

    Lewis, J. L.

    1979-01-01

    This paper considers multiple access techniques for a mobile radio system which incorporates a geosynchronous orbiting satellite repeater through which mobile terminals communicate. The communication capacities of FDMA, TDMA and CDMA systems are examined for a 4 MHz bandwidth system to serve up to 10,000 users. An FDMA system with multibeam coverage is analyzed in detail. The system includes an order-wire network for demand-access control and reassignment of satellite channels. Satellite and terminal configurations are developed to a block diagram level and system costs and implementation requirements are discussed.

  13. CEOS Committee on Earth Observations Satellites Consolidated Report, 1992

    NASA Technical Reports Server (NTRS)

    1992-01-01

    A concise overview of the committee on Earth Observations Satellites (CEOS) and its Working Groups, covering the history and purpose of the Committee and its accomplishments to date are provided. The report will be updated annually before each Plenary meeting, and as developments in the Working Groups warrant. The committee on Earth Observations Satellites (originally named the International Earth Observations Satellite committee, IEOS) was treated in 1984, in response to a recommendation from the Economic Summit of Industrialized Nations Working Group on Growth, Technology, and Employment's Panel of Experts on Satellite Remote Sensing. This group recognized the multidisciplinary nature of satellite Earth observations, and the value of coordinating across all proposed missions. Thus, CEOS combined the previously existing groups for coordination on Ocean Remote-Sensing Satellites (CORSS) and coordination on Land Remote-Sensing Satellites (CLRSS), and established a broad framework for coordination across all spaceborne Earth observations missions. The first three LEOS Plenary meetings focused on treating and guiding the Working Groups deemed necessary to carry out the objectives of the CEOS members. After the third meeting, it was agreed that a more active orientation was required by the Plenary, and additional issues were brought before the group at the fourth meeting. At the fifth Plenary, international scientific programs and relevant intergovernmental organizations accepted invitations and participated as affiliate members of CEOS. This enabled progress toward integrating satellite data users' requirements into the CEOS process. Data exchange principles for global change research were also adopted. An interim CEOS Plenary meeting was held in April 1992, in preparation for the United Nations Conference on Environment and Development (UNCED). Brief encapsulations of the Plenary sessions immediately follow the Terms of Reference that govern the activities of CEOS as a whole; Terms of Reference for the individual Working Groups are included as Appendix A. A complete listing of CEOS members is offered as Appendix B.

  14. Small Earth Observing Satellites Flying with Large Satellites in the A-Train

    NASA Technical Reports Server (NTRS)

    Kelly, Angelita C.; Loverro, Adam; Case, Warren F.; Queruel, Nadege; Marechal, Chistophe; Barroso, Therese

    2009-01-01

    This paper/poster presents a real-life example of the benefits of flying small satellites with other satellites, large or small, and vice versa. Typically, most small satellites fly payloads consisting of one or two instruments and fly in orbits that are independent from that of other satellites. The science data from these satellites are either used in isolation or correlated with instrument data from other satellites. Data correlation with other satellites is greatly improved when the measurements of the same point or air mass are taken at approximately the same time. Scientists worldwide are beginning to take advantage of the opportunities for improved data correlation, or coincidental science, offered by the international Earth Observing Constellation known as the A-Train (sometimes referred to as the Afternoon Constellation). Most of the A-Train satellites are small - the A-Train is anchored by two large NASA satellites (EOS-Aqua and EOS-Aura), but consists also of 5 small satellites (CloudSat, CALIPSO, PARASOL, OCO and Glory these last two will join in 2009). By flying in a constellation, each mission benefits from coincidental observations from instruments on the other satellites in the constellation. Essentially, from a data point of view, the A-Train can be envisioned as a single, virtual science platform with multiple instruments. Satellites in the A-Train fly at 705 km in sun-synchronous orbits. Their mean local times at the equator are within seconds to a few minutes of each other. This paper describes the challenges of operating an international constellation of independent satellites from the U.S. and Europe to maximize the coincidental science opportunities while at the same time minimizing the level of operational interactions required between team members. The A-Train mission teams have been able to demonstrate that flying as members of an international constellation does not take away the flexibility to accommodate new requirements. Specific examples will be cited, including CloudSat's relocation (to accommodate a new viewing angle for the CALIPSO satellite), Glory's replan to move closer to PARASOL, and OCO's long term plans to minimize on-orbit operations costs while maintaining safety. In all cases, safety is ensured, science returns are enhanced, and operational flexibility is retained to the maximum extent possible.

  15. FORTE satellite observations of VHF radiation from lightning discharges

    SciTech Connect

    Junor, William; Suszcynsky, D. M.; Jacobson, A. R.

    2004-01-01

    The Los Alamos National Laboratory/Sandia National Laboratory FORTE satellite is described and its capabilities for global remote sensing of lightning in the radio regime are described. Some results from 7 years of successful operation are presented. A future global lightning monitoring mission, VGLASS, is described. The FORTE satellite program has provided a powerful tool for the observation and understanding of the natural RF background due to thunderstorm activity. Unfortunately, because of hardware failures, the satellite ceased operation in late summer of 2003 after 6 years of very successful operation.

  16. Design of the American Mobile Satellite System

    NASA Technical Reports Server (NTRS)

    Kittiver, Charles

    1991-01-01

    This paper presents an overview of the American Mobile Satellite Corporation (AMSC) Mobile Satellite System (MSS). A summary of the mobile satellite (MSAT) design and overall performance is provided. The design and components of both the forward link and return link transponders are described in detail. The design and operation of a unique hybrid matrix amplifier that offers flexible power distribution is outlined. The conceptual design and performance of three types of land mobile antennas are described.

  17. Licensing of future mobile satellite systems

    NASA Technical Reports Server (NTRS)

    Lepkowski, Ronald J.

    1990-01-01

    The regulatory process for licensing mobile satellite systems is complex and can require many years to complete. This process involves frequency allocations, national licensing, and frequency coordination. The regulatory process that resulted in the establishment of the radiodetermination satellite service (RDSS) between 1983 and 1987 is described. In contrast, each of these steps in the licensing of the mobile satellite service (MSS) is taking a significantly longer period of time to complete.

  18. Recent state of the Aral sea from regular satellite observations.

    NASA Astrophysics Data System (ADS)

    Stanichny, S.; Davidov, A.; Djenidi, S.; Horstmann, U.; Stanichnaya, R.; Soloviev, D.

    The Aral Sea disaster is one of the most significant examples of ecological catastrophe caused by mismanagement of water resources. Aral sea level dropped on 22 meters for the last 35 years. The sea separated in to two independent parts , the Large Sea(Southern) and the Small Sea (Northern), loosing more than 90% of its original water masses. After the collapse of the former Soviet Union, satellite retrieved data became the main source of information on this perishing system. Regular observations from AVHRR, SeaWiFS, MODIS and ASTER satellite sensors were used for our investigations. Sea surface temperature (SST) data of the AVHRR sensor and digital bottom map topography were used for sea level drop calculations. The Sea level defined as the digital map isobate corresponds quite well to the satellite derived coastline for the Eastern part of the Large Sea with a bottom slope of ˜ 0.00015. For the period 1989-2002 the sea level of the Large Sea dropped on 9.2 meters. However in 2003 the sea level remained stable. This stabilisation was due to an increase of water output of the rivers Amu--Darya and Syr-Darya in 2003. High resolution ASTER data showed that the main amount of Syr-Darya waters is discharged into the Large Sea. The dried bottom area now covers more than 45000 km2. On the base of AVHRR-SST data the temperature regime for different parts of the Aral Sea was calculated for the years 2002-2003. The annual amplitude of the SST variation reaches 37° C for the open waters. The observed minimum freezing point was -7° C due to very high salinity. Estimations from satellite retrieved freezing points show an increase of salinity up to 10% in the Eastern part of the Large Sea. It is almost paradox that on satellite images the ice appears warmer than the water. Strong variations of the water temperature (up to 5° C) within a few days could be observed from April to August and could be related to wind induced mixing. SeaWiFS ocean colour data were used for the investigation of the optical properties of the water in different parts of the Aral Sea for the years 2002-2003. A significant relation of optical properties with wind and temperature was obtained. Strong changes of the thermal regimes of the Sea can cause variations in local climatic conditions: The analysis of AVHRR NDVI - data for the surrounding areas demonstrated a shift in the annual vegetation cycle. In addition phenomena like: salt storms, wind driven tides, sources of groundwater, eddies and frontal structures as well as ice coverage of the Aral Sea were demonstrated on satellite images.

  19. ECC Ozonesonde Calibration and Observations: Satellite Validation

    NASA Technical Reports Server (NTRS)

    Schmidlin, Francis J.; Zukor, Dorothy (Technical Monitor)

    2001-01-01

    The reliability of the Electrochemical Concentration Cell (ECC) ozonesonde depends on the care exercised in preparing the instrument for use. Although the ECC can be quickly prepared and flown, generally within less then one day if necessary, it is best to prepare the instrument at least one week prior to use, and as our tests have confirmed even 2-3 weeks prior to use may actually be better. There are a number of factors that must be considered when preparing an ECC. These basically are the pump efficiency, volumetric flow rate, temperature of the air entering the pump, and the background current. Also of importance is the concentration of the potassium iodide solution. Tests conducted at Wallops Island (38 N) has enabled us to identify potential problem areas and ways to avoid them. The calibration and pre-flight preparation methods will be discussed. The method of calibrating the ECC also is used at Ascension Island (8 S) and Natal, Brazil (5 S). Comparisons between vertical profiles of the ECC instrument and satellites will be reviewed as well as comparison with ground based instruments, such as, the Dobson Spectrophotometer and hand held Microtops photometers.

  20. Global Positioning System Satellite Selection Method

    NASA Technical Reports Server (NTRS)

    Niles, Frederick A. (Inventor)

    2001-01-01

    The satellite selection method as utilized by the spaceborne Global Positioning System receiver provides navigational solutions and is designed for use in low Earth orbit. The satellite selection method is a robust algorithm that can be used a GPS receiver to select appropriate GPS satellites for use in calculating point solutions or attitude solutions. The method is takes into account the difficulty of finding a particular GPS satellite phase code, especially when the search range in greatly increased due to Doppler shifts introduced into the carrier frequency. The method starts with an update of the antenna pointing and spacecraft vectors to determine the antenna backplane direction. Next, the GPS satellites that will potentially be in view of the antenna are ranked on a list, whereby the list is generated based on the estimated attitude and position of each GPS satellite. Satellites blocked by the Earth are not entered on this list. A second list is created, whereby the GPS satellites are ranked according to their desirability for use in attitude determination. GPS satellites are ranked according to their orthogonality to the antenna backplane, and according to geometric dilution of precision considerations. After the lists are created, the channels of the spaceborne GPS receiver are assigned to various GPS satellites for acquisition and lock. Preliminary Doppler frequencies for searching are assigned to the various channels.

  1. Evaluation of satellite-retrieved extreme precipitation using gauge observations

    NASA Astrophysics Data System (ADS)

    Lockhoff, M.; Zolina, O.; Simmer, C.; Schulz, J.

    2012-04-01

    Precipitation extremes have already been intensively studied employing rain gauge datasets. Their main advantage is that they represent a direct measurement with a relatively high temporal coverage. Their main limitation however is their poor spatial coverage and thus a low representativeness in many parts of the world. In contrast, satellites can provide global coverage and there are meanwhile data sets available that are on one hand long enough to be used for extreme value analysis and that have on the other hand the necessary spatial and temporal resolution to capture extremes. However, satellite observations provide only an indirect mean to determine precipitation and there are many potential observational and methodological weaknesses in particular over land surfaces that may constitute doubts concerning their usability for the analysis of precipitation extremes. By comparing basic climatological metrics of precipitation (totals, intensities, number of wet days) as well as respective characteristics of PDFs, absolute and relative extremes of satellite and observational data this paper aims at assessing to which extent satellite products are suitable for analysing extreme precipitation events. In a first step the assessment focuses on Europe taking into consideration various satellite products available, e.g. data sets provided by the Global Precipitation Climatology Project (GPCP). First results indicate that satellite-based estimates do not only represent the monthly averaged precipitation very similar to rain gauge estimates but they also capture the day-to-day occurrence fairly well. Larger differences can be found though when looking at the corresponding intensities.

  2. Observation of suspended sediments in Mobile Bay, Alabama from satellite

    USGS Publications Warehouse

    Stumpf, Richard P.

    1991-01-01

    As part of a comprehensive geologic study of coastal Alabama and Mississippi, the U.S. Geological Survey is investigating coastal sediment transport in Mobile Bay and the adjacent shelf. Satellite imagery from the NOAA AVHRR is being used to provide data on the variability of spatial patterns in the near-surface suspended sediment concentration. This imagery is processed using atmospheric corrections to remove haze and Rayleigh radiance in order to obtain water reflectances; the reflectances are than converted to approximate sediment concentrations using standard relationships between water reflectance and in situ sediment concentrations. A series of images from early 1990 shows rapid changes in sediment concentrations in response to high river flow of the Alabama-Tombigbee river system. During these times, suspended sediment tends to flow out Mobile Bay without mixing into the eastern lobe of the Bay (Bon Secour Bay). The sediment concentration field also appears to be disturbed by the main ship channel. The sediment plume extends more than 60 km offshore after the peak flow event. One wind event in December 1989 was identified as increasing sediment concentration in the Bay. It is not believed that such an event has been previously observed from satellite.

  3. Towards Using Satellite Altimetry for the Observation of Coastal Dynamics

    NASA Astrophysics Data System (ADS)

    Birol, F.; Roblou, L.; Lyard, F.; Llovel, W.; Durand, F.; Renault, L.; Dewitte, B.; Morrow, R.; Ménard, Y.

    2006-07-01

    The objective of this study is to determine to what extent coastal processes can be observed with satellite altimetry. Therefore, we have used a new data processing approach developed in the context of the ALBICOCCA project (Altimeter-Based Investigations in COrsica, Capraia and Contiguous Area). This approach uses improved local modelling of environmental corrections (MOG2D solutions), new experimental editing criteria and an inversion method to derive the mean sea surface. It substantially increases the number of valid data in the coastal domain and their accuracy. So far, we have used this original approach to reprocess all the TOPEX/POSEIDON altimetric data in three experimental areas: the NW Mediterranean Sea, the Northern Indian Ocean and the region of the Humboldt current system. We present the validated results and show some analyses of the coastal signal contained in these datasets.

  4. Unusual satellite data: A black hole?. [International Ultraviolet Explorer observations

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Data obtained by the NASA-launched European Space Agency's International Ultraviolet Explorer satellite suggests the possibility of a massive black hole at the center of some globular clusters (star groups) in our galaxy. Six of these clusters, three of them X-ray sources, were closely examined. Onboard short wavelength UV instrumentation penetrated the background denseness of the clusters 15,000 light years away where radiation, probably from a group of 10 to 20 bright blue stars orbiting the core, was observed. The stars may well be orbiting a massive black hole the size of 1,000 solar systems. The existence of the black hole is uncertain. The dynamics of the stars must be studied first to determine how they rotate in relation to the center of the million-star cluster. This may better indicate what provides the necessary gravitational pull that holds them in orbit.

  5. Navy satellite communications systems in transition

    NASA Astrophysics Data System (ADS)

    Newell, J. W.

    Navy SATCOM programs require advanced system engineering, program management, and long range planning to improve satellite and ground system technology. Solutions are being sought to develop Navy transitional issues within the framework of the total Defense MILSATCOM architecture. Several of the Navy SATCOM transition issues are discussed: the current Navy SATCOM baseline, consisting of three GAPFILLER (MARISAT) satellites and a constellation of geosynchronous FLTSATCOM satellites; a Demand Assignment time-division Multiple Access (DAMA) system, which permits a more efficient use of the 25 kHz FLTSAT hard-limiting transponders. A leased satellite (LEASAT) will provide extended UHF SATCOM service at four geosynchronous orbital locations. The navy also plans to increase connectivity, capacity, and AJ protection of Fleet Satellite Communications by introduction of SHF service.

  6. Small satellite radiometric measurement system

    SciTech Connect

    Weber, P.G.

    1992-01-01

    A critical need for the US Global Change Research Program is to provide continuous, well-calibrated radiometric data for the earth's radiation budget. This paper describes a new, compact, relatively light-weight, adaptable radiometer which will provide both spectrally integrated measurements and data in selected spectral bands. The radiometer design is suitable for use on small satellites, aircraft, or remotely piloted aircraft (RPAs). An example of the implementation of this radiometer on a small satellite is given. Significant benefits derive from simultaneous measurements of specific narrow (in wavelength) spectral features; such data may be obtained by combining LARI with a compact spectrometer on the same platform. Well-chosen satellite orbits allow one to use data from other satellites (e.g. DMSP) to enhance the data product, or to provide superior coverage of specific locations. 23 refs.

  7. Small satellite radiometric measurement system

    SciTech Connect

    Weber, P.G.

    1992-01-01

    A critical need for the US Global Change Research Program is to provide continuous, well-calibrated radiometric data for the earth`s radiation budget. This paper describes a new, compact, relatively light-weight, adaptable radiometer which will provide both spectrally integrated measurements and data in selected spectral bands. The radiometer design is suitable for use on small satellites, aircraft, or remotely piloted aircraft (RPAs). An example of the implementation of this radiometer on a small satellite is given. Significant benefits derive from simultaneous measurements of specific narrow (in wavelength) spectral features; such data may be obtained by combining LARI with a compact spectrometer on the same platform. Well-chosen satellite orbits allow one to use data from other satellites (e.g. DMSP) to enhance the data product, or to provide superior coverage of specific locations. 23 refs.

  8. Observations of Uranus' satellites: Bibliography and literature search

    NASA Technical Reports Server (NTRS)

    Jacobson, R. A.

    1985-01-01

    A literature search has yielded more than 10,000 observations of the satellites of Uranus made from 1787 to 1985. The type (photographic, micrometer) and the number of observations are tabulated in 5 year increments and a complete bibliography is provided.

  9. Shaft Inflation and the Planck satellite observations

    E-print Network

    Dimopoulos, Konstantinos

    2015-01-01

    A new family of inflation models is introduced and studied. The models are characterised by a scalar potential which, far from the origin, approaches an inflationary plateau in a power-law manner, while near the origin becomes monomial, as in chaotic inflation. The models are obtained in the context of global supersymmetry starting with a superpotential, which interpolates from a generalised monomial to an O'Raifearteagh form for small to large values of the inflaton field respectively. It is demonstrated that the observables obtained, such as the scalar spectral index, its running and the tensor to scalar ratio, are in excellent agreement with the latest observations, without any fine-tuning. Moreover, by widening mildly the shaft in field space, it is shown that sizable tensors can be generated, which may well be observable in the near future.

  10. Multi-sensor Observations of the SpinSat Satellite

    NASA Astrophysics Data System (ADS)

    Hall, D.

    The Naval Research Laboratory developed and launched the spherical SpinSat satellite to accomplish two primary goals: 1) study the performance of a new class of micro-thrusters, and 2) provide a calibrated drag experiment to characterize Earth's upper atmosphere during the current period of relatively high solar activity. The 55.9 cm diameter aluminum sphere is equipped with a set of Electrically-Controlled Solid Propellant (ESP) thrusters, oriented to allow both translational and spin-up/spin-down maneuvers. To facilitate remote observations of the satellite's spin rate, the sphere's exterior features a reflectance pattern much like that of a beach-ball, as well as an ensemble of light-emitting diodes (LEDs) arranged along a meridian (i.e., a line of longitude) which can be turned on for brief periods. The Air Force Research Laboratory has conducted optical observations of SpinSat from several ground-based sensors, and more are planned. The observational goals include: 1) obtaining time-resolved, multi-band measurements of the satellite actively firing its micro-thrusters, 2) characterizing the detectability and spatial/temporal morphology of the ESP thruster plumes, 3) measuring the spin rate of the satellite with the LEDs turned on, ideally before and after a spin rate adjustment maneuver, and 4) measuring the spin rate of the satellite in its completely inactive mode, using only passive observations of reflected light and/or thermal emissions.

  11. Astrometry of the main satellites of Uranus: 18 years of observations

    NASA Astrophysics Data System (ADS)

    Camargo, J. I. B.; Magalhães, F. P.; Vieira-Martins, R.; Assafin, M.; Braga-Ribas, F.; Dias-Oliveira, A.; Benedetti-Rossi, G.; Gomes-Júnior, A. R.; Andrei, A. H.; da Silva Neto, D. N.

    2015-10-01

    Context. We contribute to developing dynamical models of the motions of Uranus' main satellites. Aims: We determine accurate positions of the main satellites of Uranus: Miranda, Ariel, Umbriel, Titania, and Oberon. Positions of Uranus, as derived from those of these satellites, are also determined. The observational period spans from 1992 to 2011. All runs were made at the Pico dos Dias Observatory, Brazil. Methods: We used the software called Platform for Reduction of Astronomical Images Automatically (PRAIA) to perform a digital coronography to minimise the influence of the scattered light of Uranus on the astrometric measurements and to determine accurate positions of the main satellites. The positions of Uranus were then indirectly determined by computing the mean differences between the observed and ephemeris positions of these satellites. A series of numerical filters was applied to filter out spurious data. These filters are mostly based on (a) the comparison between the positions of Oberon with those of the other satellites and on (b) the offsets as given by the differences between the observed and ephemeris positions of all satellites. Results: We have, for the overall offsets of the five satellites, -29 mas (±63 mas) in right ascension and -27 mas (±46 mas) in declination. For the overall difference between the offsets of Oberon and those of the other satellites, we have +3 mas (±30 mas) in right ascension and -2 mas (±28 mas) in declination. Ephemeris positions for the satellites were determined from DE432+ura111. Comparisons using other modern ephemerides for the solar system - INPOP13c - and for the motion of the satellites - NOE-7-2013 - were also made. They confirm that the largest contribution to the offsets we find comes from the motion of the barycenter of the Uranus system around the barycenter of the solar system, as given by the planetary ephemerides. For the period from 1992 to 2011, our final catalogues contain 584 observed positions of Miranda, 1710 of Ariel, 1987 of Umbriel, 2588 of Titania, 2928 of Oberon, and 3516 of Uranus. Based on observations made at the Pico dos Dias Observatory/ LNA.Tables with the positions of Uranus and its satellites, as well as with the X and Y CCD coordinates of the observed satellites and reference stars are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/582/A8

  12. Planning and Scheduling for Fleets of Earth Observing Satellites

    NASA Technical Reports Server (NTRS)

    Frank, Jeremy; Jonsson, Ari; Morris, Robert; Smith, David E.; Norvig, Peter (Technical Monitor)

    2001-01-01

    We address the problem of scheduling observations for a collection of earth observing satellites. This scheduling task is a difficult optimization problem, potentially involving many satellites, hundreds of requests, constraints on when and how to service each request, and resources such as instruments, recording devices, transmitters, and ground stations. High-fidelity models are required to ensure the validity of schedules; at the same time, the size and complexity of the problem makes it unlikely that systematic optimization search methods will be able to solve them in a reasonable time. This paper presents a constraint-based approach to solving the Earth Observing Satellites (EOS) scheduling problem, and proposes a stochastic heuristic search method for solving it.

  13. NASA Satellite Observations: A Unique Asset for the Study of the Environment and Implications for Public Health

    NASA Technical Reports Server (NTRS)

    Estes Sue M.

    2010-01-01

    This slide presentation highlights how satellite observation systems are assets for studying the environment in relation to public health. It includes information on current and future satellite observation systems, NASA's public health and safety research, surveillance projects, and NASA's public health partners.

  14. NASDA satellite mission operation system and operations

    NASA Technical Reports Server (NTRS)

    Yamaya, Kousaku; Yoshida, Fumiyoshi; Noguchi, Harushige; Takahashi, Tetsuo; Tanaka, Kazuhiro

    1993-01-01

    NASDA has recently developed a new tracking and control system as a basis for future satellite mission operation. It is named type-I Space Operations and Data Systems (type-I SODS). The software of this system is separated into three parts: operation and control system, network system, and support and information system. The operation control system treats telemetry and command operations. The network system controls the communication line and ground station equipments to connect the satellite and the operation control system. The support and information system provides to other systems necessary information. JERS-1 which was launched in February of this year is the first satellite operated by type-l SODS. We explain the architecture and operation methods of this system using JERS-1 mission operations.

  15. Anti-sway control of tethered satellite systems using attitude control of the main satellite

    NASA Astrophysics Data System (ADS)

    Yousefian, Peyman; Salarieh, Hassan

    2015-06-01

    In this study a new method is introduced to suppress libration of a tethered satellite system (TSS). It benefits from coupling between satellites and tether libration dynamics. The control concept uses the main satellite attitude maneuvers to suppress librational motion of the tether, and the main satellite's actuators for attitude control are used as the only actuation in the system. The study considers planar motion of a two body TSS system in a circular orbit and it is assumed that the tether's motion will not change it. Governing dynamic equations of motion are derived using the extended Lagrange method. Controllability of the system around the equilibrium state is studied and a linear LQG controller is designed to regulate libration of the system. Tether tension and satellite attitude are assumed as only measurable outputs of the system. The Extended Kalman Filter (EKF) is used to estimate states of the system to be used as feedback to the controller. The designed controller and observer are implemented to the nonlinear plant and simulations demonstrate that the controller lead to reduction of the tether libration propoerly. By the way, because the controller is linear, it is applicable only at low amplitudes in the vicinity of equilibrium point. To reach global stability, a nonlinear controller is demanded.

  16. History of telescopic observations of the Martian satellites

    NASA Astrophysics Data System (ADS)

    Pascu, D.; Erard, S.; Thuillot, W.; Lainey, V.

    2014-11-01

    This article intends to review the different studies of the Mars satellites Phobos and Deimos realized by means of ground-based telescopic observations as well in the astrometry and dynamics domain as in the physical one. This study spans the first period of investigations of the Martian satellites since their discovery in 1877 through the astrometry and the spectrometry methods, mainly before the modern period of the space era. It includes also some other observations performed thanks to the Hubble Space Telescope. The different techniques used and the main results obtained for the positionning, the size estimate, the albedo and surface composition are described.

  17. A new digital land mobile satellite system

    NASA Technical Reports Server (NTRS)

    Schneider, Philip

    1990-01-01

    A description is given of the different digital services planned to be carried over existing and planned mobile satellite systems. These systems are then compared with analog services in terms of bandwidth and power efficiency. This comparison provides the rationale for the establishment of a digital land mobile satellite service (DLMSS) to use frequencies that are currently available but not yet assigned to a domestic mobile satellite system in the United States. The focus here is on the expected advantages of digital transmission techniques in accommodating additional mobile satellite systems in this portion of the spectrum, and how such techniques can fully satisfy voice, data and facsimile mobile communications requirements in a cost effective manner. A description is given of the system architecture of the DMLSS service proposed by the Geostar Messaging Corporation (GMC) and the market potential of DLMSS.

  18. Asian Dust Weather Categorization with Satellite and Surface Observations

    NASA Technical Reports Server (NTRS)

    Lin, Tang-Huang; Hsu, N. Christina; Tsay, Si-Chee; Huang, Shih-Jen

    2011-01-01

    This study categorizes various dust weather types by means of satellite remote sensing over central Asia. Airborne dust particles can be identified by satellite remote sensing because of the different optical properties exhibited by coarse and fine particles (i.e. varying particle sizes). If a correlation can be established between the retrieved aerosol optical properties and surface visibility, the intensity of dust weather can be more effectively and consistently discerned using satellite rather than surface observations. In this article, datasets consisting of collocated products from Moderate Resolution Imaging Spectroradiometer Aqua and surface measurements are analysed. The results indicate an exponential relationship between the surface visibility and the satellite-retrieved aerosol optical depth, which is subsequently used to categorize the dust weather. The satellite-derived spatial frequency distributions in the dust weather types are consistent with China s weather station reports during 2003, indicating that dust weather classification using satellite data is highly feasible. Although the period during the springtime from 2004 to 2007 may be not sufficient for statistical significance, our results reveal an increasing tendency in both intensity and frequency of dust weather over central Asia during this time period.

  19. Automatic Discovery of Classification and Estimation Algorithms for Earth-Observation Satellite Imagery

    E-print Network

    Fernandez, Thomas

    Imagery RickL. Riolo Program for Study of ComplexSystems (PSCS) University of Michigan AnnArbor, Michigan rlriolo@umich.edu Mark P. Line Control Data Systems,Inc. Seattle, Washington Mark.P.Line@cdc.com Abstract Under NASA'snew Earth Observing System (EOS), satellite imageryis expectedto arrive backonEarthat rates

  20. Satellite voice broadcast. Volume 2: System study

    NASA Technical Reports Server (NTRS)

    Bachtell, E. E.; Bettadapur, S. S.; Coyner, J. V.; Farrell, C. E.

    1985-01-01

    The Technical Volume of the Satellite Broadcast System Study is presented. Designs are synthesized for direct sound broadcast satellite systems for HF-, VHF-, L-, and Ku-bands. Methods are developed and used to predict satellite weight, volume, and RF performance for the various concepts considered. Cost and schedule risk assessments are performed to predict time and cost required to implement selected concepts. Technology assessments and tradeoffs are made to identify critical enabling technologies that require development to bring technical risk to acceptable levels for full scale development.

  1. Tropospheric effects of satellite power systems

    SciTech Connect

    Brubaker, K.L.; Lee, J.

    1980-01-01

    The construction and operation of a system of solar power satellites is expected to have a variety of effects on the troposphere. The launching of large space vehicles affects the air quality in the vicinity of the launch site, and the ground cloud associated with such a launch is known to stimulate the growth of water clouds under some circumstances. The transmission of power from satellite to the Earth's surface may affect certain meteorological parameters in the vicinity of the rectenna site. These and other effects are discussed in reference to the proposed solar power satellite system.

  2. A small terminal for satellite communication systems

    NASA Technical Reports Server (NTRS)

    Xiong, Fuqin; Wu, Dong; Jin, Min

    1994-01-01

    A small portable, low-cost satellite communications terminal system incorporating a modulator/demodulator and convolutional-Viterbi coder/decoder is described. Advances in signal processing and error-correction techniques in combination with higher power and higher frequencies aboard satellites allow for more efficient use of the space segment. This makes it possible to design small economical earth stations. The Advanced Communications Technology Satellite (ACTS) was chosen to test the system. ACTS, operating at the Ka band incorporates higher power, higher frequency, frequency and spatial reuse using spot beams and polarization.

  3. Distance law and formation of satellite systems

    NASA Astrophysics Data System (ADS)

    Hu, Zhong-Wei; Chen, Zhi-Xiong

    In the solar system satellite systems of Jupiter, Saturn and Uranus are typical ones. The distribution of the semi-major axis of satellite orbits in each system may be expressed by an empirical formula corresponding to the Titius-Bode law. The authors found that it can be written as an = B'mBn, where B' and B are constants. Values of B' and B depend on formation conditions of each system. Satellites should be formed in the gas-satellitesimal disk around a planet and by aggregation of satellitesimals. The gas is the major component in the disk and its damping effect must play an important role in the process of aggregation of satellitesimals. It may be proved that radial small perturbation in the disk can cause the gravitational instability and the formation of gaseous rings with increased density, where satellitesimals can easy aggregat into satellites.

  4. Interactive applications of satellite observations and mesoscale numerical models

    NASA Technical Reports Server (NTRS)

    Kreitzberg, C. W.

    1976-01-01

    The impact of numerical weather prediction (NWP) and satellite meteorology on operational weather forecasting has become overwhelming in the past few years. The paper looks toward the merger of these technologies in making short range 6-18 h forecasts through the use of mesoscale NWP models. A short-range (2-18 h) mesoscale forecast system envisioned for the near future is described that includes four components: hydrodynamic numerical models, large-scale and mesoscale; satellites, polar orbiting for high latitudes and geostationary for low latitudes; mesoclimatology, derived in large part from satellite data; and special-purpose simple models and empirical relations. It is important that the components of the forecast system be developed in parallel rather than in series if the system is to be completed within five years. There is enough evidence to substantiate the revolution in the mesoscale weather prediction in the next five years.

  5. Satellite antenna management system and method

    NASA Technical Reports Server (NTRS)

    Leath, Timothy T (Inventor); Azzolini, John D (Inventor)

    1999-01-01

    The antenna management system and method allow a satellite to communicate with a ground station either directly or by an intermediary of a second satellite, thus permitting communication even when the satellite is not within range of the ground station. The system and method employ five major software components, which are the control and initialization module, the command and telemetry handler module, the contact schedule processor module, the contact state machining module, and the telemetry state machine module. The control and initialization module initializes the system and operates the main control cycle, in which the other modules are called. The command and telemetry handler module handles communication to and from the ground station. The contact scheduler processor module handles the contact entry schedules to allow scheduling of contacts with the second satellite. The contact and telemetry state machine modules handle the various states of the satellite in beginning, maintaining and ending contact with the second satellite and in beginning, maintaining and ending communication with the satellite.

  6. Observing convection with satellite, radar, and lightning measurements

    NASA Astrophysics Data System (ADS)

    Hamann, Ulrich; Nisi, Luca; Clementi, Lorenzo; Ventura, Jordi Figueras i.; Gabella, Marco; Hering, Alessandro M.; Sideris, Ioannis; Trefalt, Simona; Germann, Urs

    2015-04-01

    Heavy precipitation, hail, and wind gusts are the fundamental meteorological hazards associated with strong convection and thunderstorms. The thread is particularly severe in mountainous areas, e.g. it is estimated that on average between 50% and 80% of all weather-related damage in Switzerland is caused by strong thunderstorms (Hilker et al., 2010). Intense atmospheric convection is governed by processes that range from the synoptic to the microphysical scale and are considered to be one of the most challenging and difficult weather phenomena to predict. Even though numerical weather prediction models have some skills to predict convection, in general the exact location of the convective initialization and its propagation cannot be forecasted by these models with sufficient precision. Hence, there is a strong interest to improve the short-term forecast by using statistical, object oriented and/or heuristic nowcasting methods. MeteoSwiss has developed several operational nowcasting systems for this purpose such as TRT (Hering, 2008) and COALITION (Nisi, 2014). In this contribution we analyze the typical development of convection using measurements of the Swiss C-band Dual Polarization Doppler weather radar network, the MSG SEVIRI satellite, and the Météorage lighting network. The observations are complemented with the analysis and forecasts of the COSMO model. Special attention is given to the typical evolutionary stages like the pre-convective environment, convective initiation, cloud top glaciation, start, maximum, and end of precipitation and lightning activity. The pre-convective environment is examined using instability indices derived from SEVIRI observations and the COSMO forecasts. During the early development satellite observations are used to observe the rise of the cloud top, the growth of the cloud droplet or crystals, and the glaciation of the cloud top. SEVIRI brightness temperatures, channel differences, and temporal trends as suggested by Mecikalski et al. (2010) are used to identify convectively active regions. Additionally, retrieved physical cloud properties of state-of-the-art cloud remote sensing algorithms such as the cloud top height, multilayer flags, cloud phase, optical depth and effective radius are employed. As soon as larger particles form, radar observations complement the satellite ones. Radar datasets are used in particular to observe the precipitation intensity and type, the vertical extension and structure of the convective cells. In the mature stage convective cells might start to produce lightning. The relation between the different observables and their suitability as predictors for the further convective development are discussed, e.g. strong updrafts in the developing phase are often followed by fast anvil spreading and intense precipitation in the mature phase. Threads and hazards due to heavy precipitation, hail, and wind gusts are estimated. Hering, A. M., Germann, U., Boscacci, M., Sénési, S., 2008: Operational nowcasting of thunderstorms in the Alps during MAP D-PHASE. In Proceedings of 5th European Conference on Radar in Meteorology and Hydrology (ERAD), 30 June - 4 July 2008, Helsinki, Finland. 1-5. Copernicus: Göttingen, Germany. Hilker, N., Badoux, A., Hegg, C., 2010: Unwetterschäden in der Schweiz im Jahre 2009. Wasser Energ. Luft 102: 1-6 (in German). Mecikalski, J. R., Mackenzie, W. M., König, M., Muller, S. 2010: Use of Meteosat Second Generation infrared data in 0-1 hour convective initiation nowcasting. Part 1. Infrared fields. J. Appl. Meteorol. 49: 521-534. Nisi, L., Ambrosetti, P., Clementi, L., 2014: Nowcasting severe convection in the Alpine region: the COALITION approach. QJRMT, 140, 682, 1684-1699, DOI: 10.1002/qj.2249

  7. Greenland surface albedo changes 1981-2012 from satellite observations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Significant melt over Greenland has been observed during the last several decades associated with extreme warming events over the northern Atlantic Ocean. An analysis of surface albedo change over Greenland is presented, using a 32-year consistent satellite albedo product from the Global Land Surfac...

  8. CORRECTING PHOTOLYSIS RATES ON THE BASIS OF SATELLITE OBSERVED CLOUDS

    EPA Science Inventory

    Clouds can significantly affect photochemical activities in the boundary layer by altering radiation intensity, and therefore their correct specification in the air quality models is of outmost importance. In this study we introduce a technique for using the satellite observed c...

  9. Gravity waves in the thermosphere observed by the AE satellites

    NASA Technical Reports Server (NTRS)

    Gross, S. H.; Reber, C. A.; Huang, F. T.

    1983-01-01

    Atmospheric Explorer (AE) satellite data were used to investigate the spectra characteristics of wave-like structure observed in the neutral and ionized components of the thermosphere. Power spectral analysis derived by the maximum entropy method indicate the existence of a broad spectrum of scale sizes for the fluctuations ranging from tens to thousands of kilometers.

  10. Tropospheric carbon monoxide: satellite observations and their applications 

    E-print Network

    MacCallum, Stuart Neil

    2008-01-01

    of greenhouse gases such as CH4 and O3. Consequently, CO has an atmospheric lifetime of 1-3 months, making it a good tracer for studying the long range transport of pollution. Satellite observations present a valuable tool to investigate tropospheric CO...

  11. Sensor Web Interoperability Testbed Results Incorporating Earth Observation Satellites

    NASA Technical Reports Server (NTRS)

    Frye, Stuart; Mandl, Daniel J.; Alameh, Nadine; Bambacus, Myra; Cappelaere, Pat; Falke, Stefan; Derezinski, Linda; Zhao, Piesheng

    2007-01-01

    This paper describes an Earth Observation Sensor Web scenario based on the Open Geospatial Consortium s Sensor Web Enablement and Web Services interoperability standards. The scenario demonstrates the application of standards in describing, discovering, accessing and tasking satellites and groundbased sensor installations in a sequence of analysis activities that deliver information required by decision makers in response to national, regional or local emergencies.

  12. The Saturn System's Icy Satellites: New Results from Cassini

    NASA Technical Reports Server (NTRS)

    Lopes-Gautier, Rosaly M.; Buratti, Bonnie; Hendrix, A. R.

    2008-01-01

    Cassini-Huygens is a multidisciplinary, international planetary mission consisting of an orbiting spacecraft and a probe. The Huygens probe successfully landed on Titan's surface on January 14, 2005, while the orbiter has performed observations of Saturn, its rings, satellites, and magnetosphere since it entered orbit around Saturn on July 1, 2004. The Cassini mission has been prolific in its scientific discoveries about the Saturn system. In this special section, we present new mission results with a focus on the 'icy satellites,' which we define as all Saturn's moons with the exception of Titan. The results included in this section have come out of the Cassini SOST--Satellites Orbiter Science Team--a multi-instrument and multidiscipline group that works together to better understand the icy satellites and their interactions with Saturn and its rings. Other papers included in this issue present ground-based observations and interior modeling of these icy moons.

  13. Globally Gridded Satellite (GridSat) Observations for Climate Studies

    NASA Technical Reports Server (NTRS)

    Knapp, Kenneth R.; Ansari, Steve; Bain, Caroline L.; Bourassa, Mark A.; Dickinson, Michael J.; Funk, Chris; Helms, Chip N.; Hennon, Christopher C.; Holmes, Christopher D.; Huffman, George J.; Kossin, James P.; Lee, Hai-Tien; Loew, Alexander; Magnusdottir, Gudrun

    2012-01-01

    Geostationary satellites have provided routine, high temporal resolution Earth observations since the 1970s. Despite the long period of record, use of these data in climate studies has been limited for numerous reasons, among them: there is no central archive of geostationary data for all international satellites, full temporal and spatial resolution data are voluminous, and diverse calibration and navigation formats encumber the uniform processing needed for multi-satellite climate studies. The International Satellite Cloud Climatology Project set the stage for overcoming these issues by archiving a subset of the full resolution geostationary data at approx.10 km resolution at 3 hourly intervals since 1983. Recent efforts at NOAA s National Climatic Data Center to provide convenient access to these data include remapping the data to a standard map projection, recalibrating the data to optimize temporal homogeneity, extending the record of observations back to 1980, and reformatting the data for broad public distribution. The Gridded Satellite (GridSat) dataset includes observations from the visible, infrared window, and infrared water vapor channels. Data are stored in the netCDF format using standards that permit a wide variety of tools and libraries to quickly and easily process the data. A novel data layering approach, together with appropriate satellite and file metadata, allows users to access GridSat data at varying levels of complexity based on their needs. The result is a climate data record already in use by the meteorological community. Examples include reanalysis of tropical cyclones, studies of global precipitation, and detection and tracking of the intertropical convergence zone.

  14. Astrometric observations of the faint satellites of Jupiter during the 1975 - 1976 opposition

    NASA Technical Reports Server (NTRS)

    Mulholland, J. D.; Shelus, P. J.; Benedict, G. F.

    1979-01-01

    The series of astrometric observations of the satellites of the trans-martian planets re-established at the McDonald Observatory in 1972 is continued. The positions deduced from photographic observations of the jovian system obtained during the 1975-76 opposition are presented together with the discovery positions of four asteroids found on these plates.

  15. DEMETER Satellite Observations of Particle Burst Prior to Chile Earthquake

    E-print Network

    Zhang, Zhenxia; Shen, Xuhui; Ma, Yuqian; Chen, Huaran; You, Xinzhao; Yuan, Yahong

    2010-01-01

    The lithosphere activity during seismogenic or occurrence of one earthquake may emit electromagnetic wave which propagate to ionosphere and radiation belt, then induce disturbance of electric and magnetic field and the precipitation of high energy charged particles. This paper, based on the data detected by DEMETER satellite, present the high energy charged particle burst(PB) with 4 to 6 times enhancement over the average value observed about ten days days before Chile earthquake. The obvious particle burst was also observed in the northern hemisphere mirror points conjugate of epicenter and no PB events in different years over the same epicenter region was found. The energy spectra of the PBs are different from the one averaged within the first three months in 2010. At the same time, the disturbance of the VLF electric spectrum in ionosphere over the epicenter detected by the DEMETER satellite are also observed in the same two orbits. Those observations from energetic PB and VLF electric spectrum disturbance...

  16. Satellite reconnaissance

    NASA Astrophysics Data System (ADS)

    Deloor, G. P.

    1984-06-01

    The potential of the observation equipment in remote sensing satellites is described. United States meteorology, land use and oceanography satellites and the major US Earth observation programs are listed. Imaging satellite systems are described such as: visible light and near infrared, thermal IR window, and microwave window. It is concluded that a geometrical resolution between 10 and 40 m can be expected. In order to reduce the data flow from the satellite system the input side of the system (the object-sensor interaction) has to be known. Satellites with synthetic aperture radar are increasingly important, but satellites can never fully replace observations with aircraft and drones.

  17. A land mobile satellite data system

    NASA Technical Reports Server (NTRS)

    Kent, John D. B.

    1990-01-01

    The Telesat Mobile Incorporated (TMI) Mobile Data System (MDS) was developed to apply satellite technology to the transportation industry's requirement for a fleet management system. It will provide two-way messaging and automatic position reporting capabilities between dispatch centers and customers' fleets of trucks. The design was based on the Inmarsat L-Band space segment with system link parameters and margins adjusted to meet the land mobile satellite channel characteristics. The system interfaces with the Teleglobe Des Laurentides earth station at Weir, Quebec. The signaling protocols were derived from the Inmarsat Standard C packet signalling system with unique trucking requirements incorporated where necessary.

  18. Satellite observations of transient radio impulses from thunderstorms

    SciTech Connect

    Argo, P.E.; Kirkland, M.; Jacobson, A.; Massey, R.; Suszynsky, D.; Eack, K.; Fitzgerald, T.J.; Smith, D.

    1999-06-01

    Transient radio emissions from thunderstorms detected by satellites were first reported in 1995. The nature and source of these emissions remained a mystery until the launch of the FORTE satellite in 1997. FORTE, with its more sophisticated triggering and larger memory capacity showed that these emissions were connected to major thunderstorm systems. The analysis reported here, connecting FORTE RF events with ground based lightning location data from the National Lightning Detection Network (NLDN), shows that localized regions within thunderstorms are responsible for the creation of the satellite detected rf signals. These regions are connected with the areas of strong radar returns from the NEXRAD Doppler radar system, indicating that they are from regions of intense convection. The authors will also show data from several storms detected in the extended Caribbean, in which the height profile of the source regions can be determined. Although as a single low earth orbit satellite FORTE cannot provide global coverage of thunderstorm/lightning events, follow-on satellite constellations should be able to provide detailed information on global lightning in near real-time.

  19. NOAA polar satellite calibration: A system description

    NASA Astrophysics Data System (ADS)

    Paris, Cecil A.

    1994-02-01

    The operational processing of polar satellite data has undergone many evolutionary changes since the launch of TIROS-N in 1978. These changes have resulted in both functional and organizational changes within NESDIS. In general, corporate knowledge of the detailed steps involved in processing satellite data has been greatly diminished. The following describes several factors contributing to our current situation: decreasing staff/budget and non-replacement of key positions, prompting centralization of many separate functions into one functional element; re-hosting of applications software from the original TIROS-N satellite processing subsystem to an IBM mainframe system (all capabilities inherent to the current system were not transferred in totality to the new system); the lack of properly documented software, procedures, and methodologies associated with detailed, step-by-step processing of satellite data, i.e. pre-launch, early orbit support, in-flight calibration, etc. In efforts to mitigate any further erosion of our knowledge base of operational satellite data processing with respect to calibration, this report is intended to document the instructional guidelines for processing of pre-launch and in-flight calibration data for instruments aboard the NOAA Polar-orbiting Operational Environmental Satellites (POES). Its purpose is to familiarize the reader--the user and managers of satellite acquired environmental data or data systems--with the basic operational technology, terminology and status of the NOAA polar satellite calibration system. Thus, a very brief description of calibration, radiometry, POES instrumentation, and procedures for prelaunch, early-orbit, in-flight, and post-launch support have been included as these subjects pertain to operational calibration.

  20. NASA Perspectives on Earth Observations from Satellite or 50 Years of Meteorological Satellite Experiments-The NASA Perspective

    NASA Technical Reports Server (NTRS)

    Einaudi, Franco

    2010-01-01

    The NASA was established in 1959. From those very eady days to the present NASA has been intimately involved with NOAA and the scientific community in the development and operation of satellite and sensor experiments. The early efforts included experiments on the TIROS and geostationary Applications Technology Satellites (ATS) series. In the latter case the spin-scan cameras conceived by Verner Suomi, along with the TIROS cameras, opened new vistas at what could be done in meteorological studies with the daily, nearly global, synoptic views from space-borne sensors As the years passed and the Nimbus series of satellites came into being in the 1960's, more quantitative observations with longer-lifetime, increasingly capable, better calibrated instruments came into being. NASA, in collaboration with and in support of NOAA, implemented operational systems that we now know as the Polar Operational Environmental Satellite (POES) series and the Geostationary Operational Environmental Satellite (GOES) series that provided dependable, continuous, dedicated satellite observations for use by the weather and atmospheric science communities. Through the 1970's, 1980's, and 1990's improved, well-calibrated instruments with more spectral bands extending into the thermal and the microwave portions of the electromagnetic spectrum were provided to obtain accurate soundings of the atmosphere, atmospheric chemistry constituents such as ozone, global sea surface temperature, snow and ice extent, vegetation dynamics, etc. In the 1990's and up to the present the NASA/Earth Observing System (EOS) has been developed, implemented, and operated over many years to provide a very comprehensive suite of observations of the atmosphere, as well as land and ocean parameters. The future looks bright wherein the development of new systems, broadly described by the National Academy of Science Decadal Study, is now underway. NASA, along with collaborations with NOAA, other agencies, and the scientific and applications communities looks forward to achieving in the years to come goals possible with the global information provided by satellites and continuously improved with technology development, joint data assimilation efforts, and attendant research studies.

  1. Whistler-triggered emissions observed by ISIS satellites

    NASA Technical Reports Server (NTRS)

    Nakamura, Y.; Ondoh, T.

    1989-01-01

    A statistical examination has been conducted of the ducted and nonducted whistler-triggered emissions (WTEs) observed by the ISIS satellites in the 1979-1981 period. Most WTEs are observed with simultaneous lower hybrid resonance in the topside ionosphere. The VLF emissions triggered by ducted whistlers frequently occur at L of 2-3, while those triggered by nonducted whistlers occur in the wider latitudinal regions at L of 2.2-4.3.

  2. The Ellipso (TM) mobile satellite system

    NASA Technical Reports Server (NTRS)

    Castiel, David; Draim, John E.

    1995-01-01

    The Ellipso(trademark) Mobile Satellite System is conceived to extend telecommunication services throughout the world to users that are not well, or not at all served by existing mobile or fixed telephone systems. Unlike cellular telephones, Ellipso(trademark) offers fully nationwide service to every served country, thereby providing service to users located anywhere within the national boundaries, no matter how isolated or remote. With Ellipso(trademark), a user in the middle of a wilderness area will have the same mobile telecommunications service as a user in a major metropolitan area. Ellipso(trademark) uses medium earth orbiting (MEO) satellites and an efficient system design to reach its subscribers directly and at a price that is competitive with terrestrial telephone services. The subscriber only requires a clear view of a serving satellite to achieve a connection and to connect to anyone else served by the national telecommunications system. Subscribers within view of two or more satellites will benefit from Ellipso's(trademark) unique satellite diversity processing, using all available satellites simultaneously to optimize circuit quality.

  3. Remote Observing with the Keck Telescope Using the ACTS Satellite

    NASA Technical Reports Server (NTRS)

    Cohen, Judy; Shopbell, Patrick; Bergman, Larry

    1998-01-01

    As a technical demonstration project for the NASA Advanced Communications Technology Satellite (ACTS), we have implemented remote observing on the 10-meter Keck II telescope on Mauna Kea in Hawaii from the California Institute of Technology campus in Pasadena. The data connection consists of optical fiber networks in Hawaii and California, connecting the end-points to high data rate (HDR) ACTS satellite antennae at JPL in Pasadena and at the Tripler Army Medical Center in Honolulu. The terrestrial fiber networks run the asynchronous transfer mode (ATM) protocol at DS-3 (45 Mbit/sec) speeds, providing ample bandwidth to enable remote observing with a software environment identical to that used for on-site observing in Hawaii. This experiment has explored the data requirements of remote observing with a modern research telescope and large-format detector arrays. While the maximum burst data rates are lower than those required for many other applications (e.g., HDTV), the network reliability and data integrity requirements are critical. As we show in this report, the former issue particularly may be the greatest challenge for satellite networks for this class of application. We have also experimented with the portability of standard TCP/IP applications to satellite networks, demonstrating the need for alternative TCP congestion algorithms and minimization of bit error rates (BER). Reliability issues aside, we have demonstrated that true remote observing over high-speed networks provides several important advantages over standard observing paradigms. Technical advantages of the high-speed network access include more rapid download of data to a user's home institution and the opportunity for alternative communication facilities between members of an observing team, such as audio- and videoconferencing.

  4. Satellite power system salvage and disposal alternatives

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A wide range of salvage options for the SPS satellite, ranging from use in and beyond geosynchronous orbit to use in low Earth orbit in return and use on Earth are presented. The satellite can be used intact to provide power for various purposes, it can be cannibalized or it can be melted down to supply materials for space or ground based products. The use of SPS beyond its nominal lifetime provides value that can be deducted from the SPS capital investment cost. The present value of the salvage value of the SPS satellites, referenced to the system initial operation data, is on the order of five to ten percent of its on-orbit capital cost. (Given a 30 year satellite lifetime and a four percent discount rate, the theoretical maximum salvage value is 30.8 percent of the capital cost.) The SPS demonstration satellite is available some 30 years earlier than the first full scale SPS satellite and has a salvage value on the order of 80 percent of its on-orbit capital cost. In the event that it becomes desirable to dispose of either the demonstration of full scale SPS satellite, a number of disposal options is presented for which intact disposal costs are less than one percent of capital costs.

  5. Critical areas: Satellite power systems concepts

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Critical Areas are defined and discussed in the various areas pertinent to satellite power systems. The presentation is grouped into five areas (General, Space Systems, Solar Energy Conversion, Microwave Systems, and Environment/Ecology) with a sixth area (Power Relay) considered separately in an appendix. Areas for Future Consideration as critical areas are discussed in a second appendix.

  6. A Metric to Evaluate Mobile Satellite Systems

    NASA Technical Reports Server (NTRS)

    Young, Elizabeth L.

    1997-01-01

    The concept of a "cost per billable minute" methodology to analyze mobile satellite systems is reviewed. Certain assumptions, notably those about the marketplace and regulatory policies, may need to be revisited. Fading and power control assumptions need to be tested. Overall, the metric would seem to have value in the design phase of a system and for comparisons between and among alternative systems.

  7. Principle characteristics of the National Earth Observation Satellite. Project SPOT

    NASA Technical Reports Server (NTRS)

    Cazenave, M.

    1977-01-01

    A recent meeting of the Economic and Social Committee examined the programs and means currently being implemented by France in the field in the field of space research and industry which could bring about fast results. This was prompted by man's desire to insure rational resource management of his planet and by man's awareness of the definite contribution that space observation can make to this field of research. Through discussion, the Economic and Social Committee has approved the plan for creating an earth observation satellite. A detailed discussion of the principle characteristics of this earth observation satellite include the objectives, the orbit, characteristics and operations of the platform, maintenance, attitude measurement, the power available and many other characteristics.

  8. Observed Weather Satellite Thermal IR Responses Prior to Earthquakes

    NASA Astrophysics Data System (ADS)

    Bryant, N. A.; Zobrist, A. L.; Logan, L. L.; Freund, F.; Nishenko, S.

    2002-12-01

    A number of observers claim to have seen thermal anomalies prior to earthquakes, but subsequent analysis by others have failed to produce similar findings. It was the purpose of this study to determine if thermal anomalies could be found in association with known earthquakes by systematically co-registering weather satellite images at the sub-pixel level and then determining if statistically significant responses had occurred prior to an event. Earthquakes associated with plate movement (strike-slip and thrust faulting), rather than volcanism, were to be considered. A new set of automatic co-registration procedures were developed for this task to accommodate all properties particular to weather satellite observations taken at night. Spacecraft and sensor ephemeris and the horizontal displacement due to elevation were all factored in, and final adjustment for minor satellite deviations (related to roll, pitch, and yaw) were made by using image-to-image tiepoint correlations. Reliance upon visual clues in an image (frequently the subject of debate in the past) is not required. The technique relies on the general condition where ground cools after sunset. The technique applies best to the use of the geosynchronous weather satellites (GOES, Meteosat, and GMS), where images are taken every thirty minutes. Use of the geosynchronous satellites also reduces the potential for miscalculation of trends due to weather front movement or local cloud/fog formation. The polar orbiting satellites have better resolution (1km vs 5km) and better signal-to-noise, but only acquire images twice during an evening, thereby making trend analysis difficult. Case studies investigated to date include the Hector Mine California and Ikrit Turkey earthquakes of 1999, and the Bhuj India quake of 2001. The result of the new analytic procedures has been the observance of apparent heating trends close to epicenters in satellite data acquisitions a few hours prior to an earthquake. When observations along known fault-lines showed a much-reduced `temperature' decline through the evening, or in some cases an actual `temperature' increase, an earthquake occurred. This result may indicate mid-infrared luminescence associated with crustal deformation(Freund, 2002), rather than heat emission. Other events are currently under investigation using the methods developed.

  9. Possible satellite-based observations of the 1997 Leonid meteoroids

    SciTech Connect

    Pongratz, M.B.; Carlos, R.C.; Cayton, T.

    1998-12-01

    The Block IIA GPS satellites are equipped with a sensor designed to detect electromagnetic transients. Several phenomena will produce triggers in this sensor. They include earth-based electromagnetic transients such as lightning and two space-based phenomena--deep dielectric discharge and meteoroid or hyper-velocity micro-gram particle impact (HMPI). Energetic electrons in the GPS environment cause the deep dielectric charging. HMPIs cause triggers through the transient electric fields generated by the ejecta plasma. During the 1997 Leonid passage the energetic particle fluxes were very low. In the presence of such low fluxes the typical median trigger rate is 20 per minute with a standard deviation of about 20 per minute. Between 0800 UT and 1200 UT on November 17, 1997, the sensor on a specially configured satellite observed trigger rates more than 10 sigma above the nominal median rate. Sensors on other Block IIA GPS satellites also observed excess triggers during November. Detection is enhanced when the sensor antenna is oriented into the Leonid radiant. While many questions persist the authors feel that it is likely that the excess events during the November interval were caused by the close approach of the satellites to the Leonid meteoroid path.

  10. Solar power satellite, system definition study. Part 2, volume 3: SPS satellite systems

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The differences in approach to solar energy conversion by solar cells and thermal engine systems are examined. Systems requirements for the solar power satellite (SPS) are given along with a description of the primary subsystems. Trades leading to exact configuration selection, for example, selection of the Rankine cycle operating temperatures are explained, and two satellite configurations are discussed.

  11. Land-mobile satellite communication system

    NASA Technical Reports Server (NTRS)

    Yan, Tsun-Yee (Inventor); Rafferty, William (Inventor); Dessouky, Khaled I. (Inventor); Wang, Charles C. (Inventor); Cheng, Unjeng (Inventor)

    1993-01-01

    A satellite communications system includes an orbiting communications satellite for relaying communications to and from a plurality of ground stations, and a network management center for making connections via the satellite between the ground stations in response to connection requests received via the satellite from the ground stations, the network management center being configured to provide both open-end service and closed-end service. The network management center of one embodiment is configured to provides both types of service according to a predefined channel access protocol that enables the ground stations to request the type of service desired. The channel access protocol may be configured to adaptively allocate channels to open-end service and closed-end service according to changes in the traffic pattern and include a free-access tree algorithm that coordinates collision resolution among the ground stations.

  12. Future satellite systems - Market demand assessment

    NASA Technical Reports Server (NTRS)

    Reiner, P. S.

    1981-01-01

    During 1979-80, a market study was performed regarding the future total demand for communications services, and satellite transmission service at the 4/6 GHz, 12/14 GHz, and 20/30 GHz frequencies. Included in the study were a variety of communications traffic characteristics as well as projections of the cost of C and Ku band satellite systems through the year 2000. In connection with the considered study, a total of 15 major study tasks and subtasks were undertaken and were all interrelated in various ways. The telecommunications service forecasts were concerned with a total of 21 data services, 5 voice services, and 5 video services. The traffic volumes within the U.S. for the three basic services were projected for three time periods. It is found that the fixed frequency allocation for domestic satellites combined with potential interference from adjacent satellites means a near term lack of orbital positions above the U.S.

  13. Correction of real-time satellite precipitation with satellite soil moisture observations

    NASA Astrophysics Data System (ADS)

    Zhan, W.; Pan, M.; Wanders, N.; Wood, E. F.

    2015-10-01

    Rainfall and soil moisture are two key elements in modeling the interactions between the land surface and the atmosphere. Accurate and high-resolution real-time precipitation is crucial for monitoring and predicting the onset of floods, and allows for alert and warning before the impact becomes a disaster. Assimilation of remote sensing data into a flood-forecasting model has the potential to improve monitoring accuracy. Space-borne microwave observations are especially interesting because of their sensitivity to surface soil moisture and its change. In this study, we assimilate satellite soil moisture retrievals using the Variable Infiltration Capacity (VIC) land surface model, and a dynamic assimilation technique, a particle filter, to adjust the Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis (TMPA) real-time precipitation estimates. We compare updated precipitation with real-time precipitation before and after adjustment and with NLDAS gauge-radar observations. Results show that satellite soil moisture retrievals provide additional information by correcting errors in rainfall bias. The assimilation is most effective in the correction of medium rainfall under dry to normal surface conditions, while limited/negative improvement is seen over wet/saturated surfaces. On the other hand, high-frequency noises in satellite soil moisture impact the assimilation by increasing rainfall frequency. The noise causes larger uncertainty in the false-alarmed rainfall over wet regions. A threshold of 2 mm day-1 soil moisture change is identified and applied to the assimilation, which masked out most of the noise.

  14. Introduction to Global Navigation Satellite System

    NASA Technical Reports Server (NTRS)

    Moreau, Michael

    2005-01-01

    This viewgraph presentation reviews the fundamentals of satellite navigation, and specifically how GPS works. It presents an overview and status of Global Positioning System, for both the current GPS, and plans to modernize it in the future. There is also a overview and status of other Global Navigation Satellite System (GNSS), specifically GLONASS, Galileo, and QZSS. There is also a review of Satellite based time transfer techniques. The topic is of interest to the Time and Frequency Community, because the Global Positioning system has become the primary system for distributing Time and frequency globally, and because it allows users to synchronize clocks and calibrate and control oscillators in any location that has a GPS antenna.

  15. ORBITAL DEPENDENCE OF GALAXY PROPERTIES IN SATELLITE SYSTEMS OF GALAXIES

    SciTech Connect

    Hwang, Ho Seong; Park, Changbom E-mail: cbp@kias.re.k

    2010-09-01

    We study the dependence of satellite galaxy properties on the distance to the host galaxy and the orbital motion (prograde and retrograde orbits) using the Sloan Digital Sky Survey (SDSS) data. From SDSS Data Release 7, we find 3515 isolated satellite systems of galaxies at z < 0.03 that contain 8904 satellite galaxies. Using this sample, we construct a catalog of 635 satellites associated with 215 host galaxies whose spin directions are determined by our inspection of the SDSS color images and/or by spectroscopic observations in the literature. We divide satellite galaxies into prograde and retrograde orbit subsamples depending on their orbital motion with respect to the spin direction of the host. We find that the number of galaxies in prograde orbit is nearly equal to that of retrograde orbit galaxies: the fraction of satellites in prograde orbit is 50% {+-} 2%. The velocity distribution of satellites with respect to their hosts is found to be almost symmetric: the median bulk rotation of satellites is -1 {+-} 8 km s{sup -1}. It is found that the radial distribution of early-type satellites in prograde orbit is strongly concentrated toward the host while that of retrograde ones shows much less concentration. We also find the orbital speed of late-type satellites in prograde orbit increases as the projected distance to the host (R) decreases while the speed decreases for those in retrograde orbit. At R less than 0.1 times the host virial radius (R < 0.1r{sub vir,host}), the orbital speed decreases in both prograde and retrograde orbit cases. Prograde satellites are on average fainter than retrograde satellites for both early and late morphological types. The u - r color becomes redder as R decreases for both prograde and retrograde orbit late-type satellites. The differences between prograde and retrograde orbit satellite galaxies may be attributed to their different origin or the different strength of physical processes that they have experienced through hydrodynamic interactions with their host galaxies.

  16. ECC Ozonesonde Reliability, Observations, and Comparisons with Satellite Ozone Instruments

    NASA Technical Reports Server (NTRS)

    Schmidlin, F. J.; Northam, E. T.; Ross, E. D.; Schauer, A. G.; Gerlach, John C. (Technical Monitor)

    2001-01-01

    Electrochemical Concentration Cell (ECC) ozone instruments depend on the quality of care exercised in their pre-flight preparation. The ozone-measuring project conducted at Goddard Space Flight Center's Wallops Flight Facility uses a number of mechanisms designed to inspect the ECC for anomalies that may interfere with the reception of valid ozone profiles. Complete electronic testing of the instrument, individually and when coupled to its radiosonde has led to exceptional monitoring of ozone for detecting long-term atmospheric changes. A number of factors are considered when preparing an ECC instrument for flight. These basically are specific calibrations of pump efficiency, volumetric flow rate, temperature of the air entering the pump, and background current. The concentration of the potassium iodide solution is also important. Wallops is the only site using a UV photometer (Dasibi) to compare ECC ozone output at various concentrations of ozone that allows adjustment to be made to offsets that may appear in the balloon-borne instrument prior to release. All of the above procedures allow identification of potential problems before release of the ECC instrument. Procedures followed at Wallops also are employed in Brazil, and Ascension Island where NASA has cooperative agreements in place to obtain ozonesondes data. All ECC instruments are prepared 3-4 weeks prior to the day of observation. We will briefly describe the instrumental tests employed. These tests have included simultaneous dual observations to compare the effect of different solution concentrations, comparison of sensors of different manufacturers, and comparisons with surface- and space-based instrumentation such as the Dobson Spectrophotometer and satellites. Vertical profiles of ozone from Arctic, mid-latitudes, and Antarctica will be discussed. Although not unusual, the data reveals ozone structure that correlate well with typical atmospheric temperatures and possibly relative humidity. Finally, vertical ozone distribution, compared with remotely measured ozone from lidar and satellite, will be discussed. Specific comparisons between ECC and HALOE measurements, integrated ECC total ozone overburden with the EP-TOMS and the Dobson, as well as comparisons with lidar are discussed. Results show agreement and some disagreement between the in situ measurements of the ECC and the remote instruments. We postulate reasons for the differences, or biases, which in spite of the excellent ECC quality control during pre-flight preparation and data analysis processes, may be due to uncertainties in both measuring systems.

  17. Extreme ultraviolet explorer satellite observation of Jupiter's Io plasma torus

    NASA Technical Reports Server (NTRS)

    Hall, D. T; Gladstone, G. R.; Moos, H. W.; Bagenal, F.; Clarke, J. T.; Feldman, P. D.; Mcgrath, M. A.; Schneider, N. M.; Shemansky, D. E.; Strobel, D. F.

    1994-01-01

    We present the first Extreme Ultraviolet Explorer (EUVE) satellite observation of the Jupiter system, obtained during the 2 day period 1993 March 30 through April 1, which shows a rich emission-line spectrum from the Io plasma torus spanning wavelengths 370 to 735 A. The emission features correspond primarily to known multiplets of oxygen and sulfur ions, but a blended feature near 372 A is a plausible Na II transition. The summed detected energy flux of (7.2 +/- 0.2) x 10(exp -11) ergs/sq cm(s) corresponds to a radiated power of approximately equal to 4 x 10(exp 11) W in this spectral range. All ansa emissions show a distinct dawn-dusk brightness asymmetry and the measured dusk/dawn ratio of the bright S III lambda-680 feature is 2.3 +/- 0.3, significantly larger than the ratio measured by the Voyager spacecraft ultraviolet (UV) instruments. A preliminary estimate of ion partitioning indicates that the oxygen/sulfur ion ratio is approximately equal to 2, compared to the value approximately equal to 1.3 measured by Voyager, and that (Na(+))/(e) greater than 0.01.

  18. Observations of the Galilean satellites of Jupiter with Pulkovo Normal Astrograph during 2009-2011

    NASA Astrophysics Data System (ADS)

    Narizhnaya, N. V.

    2015-12-01

    The paper presents the results of observations of Jupiter and its Galilean moons, performed with the Normal Astrograph ( D/ F=0.33 m/3.5 m, CCD S2C, FOV 18' × 16') at Pulkovo observatory during 2009-2011. We obtained 140 positions of the Galilean satellites and 42 calculated positions of Jupiter in the system of UCAC4 (ICRS, J2000.0) catalogue. The equatorial coordinates of satellites have been compared to eight most current theories of planetary and satellite motion. The average residuals between the observed and calculated coordinates (O-C) using the selected theories of motion do not exceed 0.08?. The behavior and magnitudes of the (O-C) residuals in the positions of Ganymede and Callisto satellites show that the theory of their motion was elaborated worse than in the case of Io and Europa satellites. Distribution of the (O-C) residuals for Callisto differs from a normal distribution. Comparison of the calculated equatorial coordinates of Jupiter, based on the observed positions of satellites and their theoretical Jovi-centric coordinates calculated using the INPOP10 theory of planetary motion revealed satisfactory results. The average residuals are, respectively, (O-C)? = 0.040? and (O-C)? =-0.053? assuming the normal distribution law.

  19. Regional Navigation System Using Geosynchronous Satellites and Stratospheric Airships

    E-print Network

    Won, Chang-Hee

    - 1 - Regional Navigation System Using Geosynchronous Satellites and Stratospheric Airships Chang navigation system using geosynchronous satellites and stratospheric airships. One important factor in designing a navigation system is dilution of precision. We design a regional navigation system based

  20. Data distribution satellite system architecture concept

    NASA Technical Reports Server (NTRS)

    Price, Kent M.; Jorasch, Ronald E.

    1990-01-01

    This paper describes a future communications satellite system architecture concept called the Data Distribution Satellite (DDS). The DDS is envisioned as a new system to be used as an adjunct to TDRS/TDAS for distributing new NASA science data throughout the U.S. as well as internationally. The DDS would also provide networking capability for interchange of science database files among science users and NASA archive depositories. Experimenters would be able to access and control their experimental packages remotely, relieving astronaut workload. This paper gives a conceptual system design based on year 1995 technology. Features of the design include use of Ku and Ka-bands, use of fixed spot beams, 2 Gb/s throughput, and on-board demodulation and switching. The satellite dry mass is 1,300 kg and end-of-life power is 4 kW.

  1. An advanced domestic satellite communications system

    NASA Technical Reports Server (NTRS)

    1980-01-01

    An updated traffic projection for U.S. domestic satellite communications service covering a period of 15 years; mid-1980 to mid-1995 was prepared. This model takes into account expected technology advances and reductions in transmission costs, legislative and regulatory changes permitting increased competition, and rising energy costs which will encourage more extensive substitution of telecommunications for travel. The historical development and current status of satellite systems are discussed as well as the characteristics of follow-on systems. Orbital arc utilization, spacecraft configuration for single shuttle launch, Earth station configuration, and system costs are examined. Areas which require technology development include multiple beam frequency reuse antennas, on-board switching, intersatellite links, and ka-band operation. Packing and deployment schemes for enclosing the satellite within the shuttle orbiter bay must also be devised.

  2. Al Gore attends Fall Meeting session on Earth observing satellite

    NASA Astrophysics Data System (ADS)

    Richman, Barbara T.

    2011-12-01

    Former U.S. vice president Al Gore, making unscheduled remarks at an AGU Fall Meeting session, said, “The reason you see so many pictures” of the Deep Space Climate Observatory (DSCOVR) satellite at this session is “that it already has been built.” However, “because one of its primary missions was to help document global warming, it was canceled. So for those who are interested in struggling against political influence,” Gore said, “the benefits have been documented well here.” Gore made his comments after the third oral presentation at the 8 December session entitled “Earth Observations From the L1 (Lagrangian Point No. 1),” which focused on the capabilities of and progress on refurbishing DSCOVR. The satellite, formerly called Triana, had been proposed by Gore in 1998 to collect climate data. Although Triana was built, it was never launched: Congress mandated that before the satellite could be sent into space the National Academies of Science needed to confirm that the science it would be doing was worthwhile. By the time the scientific validation was complete, the satellite “was no longer compatible with the space shuttle manifest,” Robert C. Smith, program manager for strategic integration at the NASA Goddard Space Flight Center, told Eos.

  3. Low-power magnetometer observation with satellite data transmission at unmanned site in Antarctica

    NASA Astrophysics Data System (ADS)

    Yamagishi, H.; Kadokura, A.

    2012-12-01

    We will report technical experiences from 6 years of unmanned low power magnetometer observation in Antarctica with daily data transmission via Iridium satellite telephone link. One of the difficulties of unmanned observation in Antarctica is dark winter months in which power supply from solar panel can not be expected. One solution for this difficulty is to minimize the power consumption (as small as ~1 W) to manage the observation in winter months with limited amount of batteries (~400Ah). Another difficulty is to collect data from the observation site. It is quite expensive and laborious to send a party to the observation site to obtain the data in Antarctica. Although cost for satellite communication is expensive, it is much more economical to collect data via satellite data link by installing a telephone terminal into the observation system. It seems that power consumption of a satellite phone (~10 W) does not fit to the low power system. However, as long as the observed data is not too large (<1 Mbyte per day), turn on period of the satellite phone is short (<1 hour per day) and the daily average of total power consumption lies within the available power of ~1 W. We have developed low-power magnetometer system with Iridium satellite phone data link. Basic design of the low-power system is similar to that developed by British Antarctic Survey (intermittent operation of magnetometer and GPS). However, we have made some improvements; reduced power consumption (0.2 W) at high sampling rate (1Hz) and increased sensitivity (0.2nT), so that geomagnetic pulsation study can be possible. In our observation system, satellite data transfer is only made in sunlit season with the total power consumption of 1 W (0.8W for Iridium phone and 0.2W for others). During dark winter months, observed data are stored in CF memory with diminished power consumption of 0.2W. When the sun comes in spring, the stored data are transmitted along with the daily observed data. It takes nearly two months to complete the transmission of data stored in winter months. We have installed two sets of low-power magnetometer at inland and coastal area in January, 2007. We added one set every austral summer and, by January 2010, 5 magnetometers are deployed within a radius of 700km from Syowa Station. The observed data can be used for the study of magnetic pulsations, as well as small and medium scale structure of ionospheric currents at the time of auroral substorm.

  4. ETS-VI multibeam satellite communications systems

    NASA Astrophysics Data System (ADS)

    Kawai, Makoto; Tanaka, Masayoshi; Ohtomo, Isao

    1989-10-01

    The fixed and mobile satellite communications systems of the Japanese Engineering Test Satellite-VI (ETS-VI) are described. The system requirements are outlined along with the system configuration. The ETS-VI multibeam system employs three frequency bands. When used for Ka-band fixed communications, it covers the Japanese main islands with thirteen 0.3-degree-wide spot beam. Four of the beams are active for ETS-VI. When used for S-band mobile communications, five beams cover the area within 200 nautical miles from the Japanese coast. The C-band beam for fixed communications covers the central area of the Japanese main islands with a single beam. The onboard antenna system is described along with the transponders and their associated onboard systems. A discussion of the system technology follows, covering the TDMA transmisssion system, the relay function, rainfall compensation, and the antenna and propagation performance.

  5. A relativistic and autonomous navigation satellite system

    E-print Network

    Delva, Pacôme; Kosti?, Uros; Carloni, Sante

    2011-01-01

    A relativistic positioning system has been proposed by Bartolom\\'e Coll in 2002. Since then, several group developed this topic with different approaches. I will present a work done in collaboration with Ljubljana University and the ESA Advanced Concepts Team. We developed a concept, Autonomous Basis of Coordinates, in order to take advantage of the full autonomy of a satellite constellation for navigation and positioning, by means of satellite inter-links. I will present the advantages of this new paradigm and a number of potential application for reference systems, geophysics and relativistic gravitation.

  6. A relativistic and autonomous navigation satellite system

    E-print Network

    Pacôme Delva; Andrej Cadez; Uros Kostic; Sante Carloni

    2011-06-17

    A relativistic positioning system has been proposed by Bartolom\\'e Coll in 2002. Since then, several group developed this topic with different approaches. I will present a work done in collaboration with Ljubljana University and the ESA Advanced Concepts Team. We developed a concept, Autonomous Basis of Coordinates, in order to take advantage of the full autonomy of a satellite constellation for navigation and positioning, by means of satellite inter-links. I will present the advantages of this new paradigm and a number of potential application for reference systems, geophysics and relativistic gravitation.

  7. Satellite Power System (SPS) public outreach experiment

    NASA Technical Reports Server (NTRS)

    Mcneal, S. R.

    1980-01-01

    An outreach experiment was conducted to improve the results of the satellite power system (SPS) concept development and evaluation program. The objectives of the outreach were to: (1) determine the areas of major concern relative to the SPS concept and (2) gain experience with an outreach process for use in future public involvement. The response to the outreach effort was positive, suggesting that the effort extended by the SPS project division to encourage an information exchange with the public was well received. The responses were analyzed and from them some questions and answers about the satellite power system are presented.

  8. Domestic mobile satellite systems in North America

    NASA Technical Reports Server (NTRS)

    Wachira, Muya

    1990-01-01

    Telest Mobile Inc. (TMI) and the American Mobile Satellite Corporation (AMSC) are authorized to provide mobile satellite services (MSS) in Canada and the United States respectively. They are developing compatible systems and are undertaking joint specification and procurement of spacecraft and ground segment with the aim of operational systems by late 1993. Early entry (phase 1) mobile data services are offered in 1990 using space segment capacity leased from Inmarsat. Here, an overview is given of these domestic MSS with an emphasis on the TMI component of the MSAT systen.

  9. Earth Observing System: Global Observations to Study the Earth's Environment

    NASA Technical Reports Server (NTRS)

    King, Michael D.

    2003-01-01

    The Earth Observing System (EOS) is a space-based observing system comprised of a series of satellite sensors by which scientists can monitor the Earth, a Data and Information System (EOSDIS) enabling researchers worldwide to access the satellite data, and an interdisciplinary science research program to interpret the satellite data. During the last couple of years, four EOS science missions were launched, representing observations of (i) total solar irradiance, (ii) Earth radiation budget, (iii) land cover & land use change, (iv) ocean processes (vector wind, sea surface temperature, and ocean color), (v) atmospheric processes (aerosol and cloud properties, water vapor, and temperature and moisture profiles), and (vi) tropospheric chemistry. In succeeding years many more satellites will be launched that will contribute immeasurably to our understanding of the Earth's environment. In this presentation I will describe how scientists are using NASA's Earth science data to examine land use and natural hazards, environmental air quality, including: dust storms over the worlds deserts, cloud and radiation properties, sea surface temperature, and winds over the ocean, with a special emphasis on satellite observations available for studying the southern African environment.

  10. Satellite observations of noctilucent clouds over the diurnal cycle

    NASA Astrophysics Data System (ADS)

    Stevens, Michael

    The Spatial Heterodyne IMager for MEsospheric Radicals (SHIMMER) was launched in March, 2007 to observe OH solar resonance fluorescence and noctilucent clouds (NLCs) near 309 nm. SHIMMER observes vertical profiles of both OH and NLCs up to 58° latitude in both hemispheres. Between 50-58° latitudes SHIMMER images the limb over 500 times a day, far more than other satellite instruments currently operating. Because SHIMMER precesses in local time by about 30 minutes/day, this high sampling rate allows for analysis of NLC frequency with local time. We present the first space-borne observations of NLC frequency over the diurnal cycle. We find that the frequency during the northern 2007 summer is dominated by a strong semidiurnal tide with large peaks near 0530 and 1800 local time. We will compare these results from the northern hemisphere to new observations from the 2007-2008 southern summer. These SHIMMER results have important implications to reconciling observations from other satellites measuring at discrete local times, particularly when quantifying any observed long-term trends in the ice content.

  11. The investigation of tethered satellite system dynamics

    NASA Technical Reports Server (NTRS)

    Lorenzini, E.

    1985-01-01

    Progress in tethered satellite system dynamics research is reported. A retrieval rate control law with no angular feedback to investigate the system's dynamic response was studied. The initial conditions for the computer code which simulates the satellite's rotational dynamics were extended to a generic orbit. The model of the satellite thrusters was modified to simulate a pulsed thrust, by making the SKYHOOK integrator suitable for dealing with delta functions without loosing computational efficiency. Tether breaks were simulated with the high resolution computer code SLACK3. Shuttle's maneuvers were tested. The electric potential around a severed conductive tether with insulator, in the case of a tether breakage at 20 km from the Shuttle, was computed. The electrodynamic hazards due to the breakage of the TSS electrodynamic tether in a plasma are evaluated.

  12. Satellite sound broadcasting system study: Mobile considerations

    NASA Technical Reports Server (NTRS)

    Golshan, Nasser

    1990-01-01

    Discussed here is the mobile reception part of a study to investigate a satellite sound broadcast system in the UHF or L bands. Existing propagation and reception measurements are used with proper interpretation to evaluate the signaling, coding, and diversity alternatives suitable for the system. Signal attenuation in streets shadowed by buildings appear to be around 29 db, considerably higher than the 10 db adopted by CCIR. With the marriage of proper technologies, an LMSS class satellite can provide substantial direct satellite audio broadcast capability in UHF or L bands for high quality mobile and portable indoor reception by low cost radio receivers. This scheme requires terrestrial repeaters for satisfactory mobile reception in urban areas. A specialized bandwidth efficient spread spectrum signalling technique is particularly suitable for the terrestrial repeaters.

  13. LNG satellites in a distribution system

    SciTech Connect

    Ellis, C.T.

    1980-04-01

    An LNG satellite system using two LNG sources has been developed by Bay State Gas Co. for Massachusetts incorporating small, portable ambient vaporizers and a large peak-shaving facility. The primary facilities at Ludlow, MA, consist of a 1 billion cu ft storage tank, equipment capable of liquefying 7.5 million cu ft/day of gas, vaporization equipment with a capacity of 55 million cu ft/day, and LNG transport trailer loading-unloading facilities. Secondary facilities are located at a similar terminal at Everett, MA. The largest satellite station has an 8 billion cu ft storage tank, equipment capable of vaporizing 35 million cu ft/day, and LNG transport trailer loading-unloading facilities. Mobile units consisting of a trailer-mounted vaporizer and an LNG trailer also are in use. Factors in safe and dependable operation of the satellite LNG system are reviewed, including local transportation restrictions.

  14. Observational and Dynamical Wave Climatologies. VOS vs Satellite Data

    NASA Astrophysics Data System (ADS)

    Grigorieva, Victoria; Badulin, Sergei; Chernyshova, Anna

    2013-04-01

    The understanding physics of wind-driven waves is crucially important for fundamental science and practical applications. This is why experimental efforts are targeted at both getting reliable information on sea state and elaborating effective tools of the sea wave forecasting. The global Visual Wave Observations and satellite data from the GLOBWAVE project of the European Space Agency are analyzed in the context of these two viewpoints. Within the first "observational" aspect we re-analyze conventional climatologies of all basic wave parameters for the last decades [5]. An alternative "dynamical" climatology is introduced as a tool of prediction of dynamical features of sea waves on global scales. The features of wave dynamics are studied in terms of one-parametric dependencies of wave heights on wave periods following the theoretical concept of self-similar wind-driven seas [3, 1, 4] and recently proposed approach to analysis of Voluntary Observing Ship (VOS) data [2]. Traditional "observational" climatologies based on VOS and satellite data collections demonstrate extremely consistent pictures for significant wave heights and dominant periods. On the other hand, collocated satellite and VOS data show significant differences in wave heights, wind speeds and, especially, in wave periods. Uncertainties of visual wave observations can explain these differences only partially. We see the key reason of this inconsistency in the methods of satellite data processing which are based on formal application of data interpolation methods rather than on up-to-date physics of wind-driven waves. The problem is considered within the alternative climatology approach where dynamical criteria of wave height-to-period linkage are used for retrieving wave periods and constructing physically consistent dynamical climatology. The key dynamical parameter - exponent R of one-parametric dependence Hs ~ TR shows dramatically less pronounced latitudinal dependence as compared to observed Hs and T of conventional climatology in both satellite and VOS data collections. It can be treated as an effect of interaction of wind-driven seas and swell on global scales as it was stated in [2]. Further study combining the alternative and conventional climatologies can help to detail this important dynamical effect of global wave dynamics. The progress in satellite data processing and their physical interpretation is of great value for such study. The work was supported by Russian Foundation for Basic Research grant 11-05-01114-a and the Russian government contracts No.11.G34.31.0035, No.11.G34.31.0078. References [1] S. I. Badulin, A. V. Babanin, D. Resio, and V. Zakharov. Weakly turbulent laws of wind-wave growth. J. Fluid Mech., 591:339-378, 2007. [2] S. I. Badulin and Grigorieva V. G. On discriminating swell and wind-driven seas in voluntary observing ship data. J. Geophys. Res., 117(C00J29), 2012. [3] S. I. Badulin, A. N. Pushkarev, D. Resio, and V. E. Zakharov. Self-similarity of wind-driven seas. Nonl. Proc. Geophys., 12:891-946, 2005. [4] E. Gagnaire-Renou, M. Benoit, and S. I. Badulin. On weakly turbulent scaling of wind sea in simulations of fetch-limited growth. J. Fluid Mech., 669:178-213, 2011. [5] S. K. Gulev, V. Grigorieva, A. Sterl, and D. Woolf. Assessment for the reliability of wave observations from voluntary observing ships: insights from the validation of a global wind wave climatology based on voluntary observing ship data. J. Geophys. Res. - Oceans, 108(C7):3236, doi:10,1029/2002JC001437, 2003.

  15. Astrometric observations of the satellites of the outer planets. I - The Galilean satellites in 1977

    NASA Technical Reports Server (NTRS)

    Ianna, P. A.; Seitzer, P.; Levinson, F.

    1979-01-01

    Astrometric observations of the Galilean satellites of Jupiter performed around the opposition of 1977 with a 67-cm photovisual refractor are reported. The measurements are reduced to absolute and intersatellite positions by two different methods: a linear least-squares plate-constant solution to the AGK3 reference-star frame and the trail-scale method of Pascu (1977). Results of a plate-constant reduction are also presented for two observations of JV (Amalthea). Comparison of the data with Liske's (1978) theoretical predictions for the intersatellite positions indicates no systematic bias in the data; a probable scatter of about 15 arcsec in both right ascension and declination is estimated.

  16. Correction of real-time satellite precipitation with satellite soil moisture observations

    NASA Astrophysics Data System (ADS)

    Zhan, W.; Pan, M.; Wanders, N.; Wood, E. F.

    2015-06-01

    Rainfall and soil moisture are two key elements in modeling the interactions between the land surface and the atmosphere. Accurate and high-resolution real-time precipitation is crucial for monitoring and predicting the on-set of floods, and allows for alert and warning before the impact becomes a disaster. Assimilation of remote sensing data into a flood-forecasting model has the potential to improve monitoring accuracy. Space-borne microwave observations are especially interesting because of their sensitivity to surface soil moisture and its change. In this study, we assimilate satellite soil moisture retrievals using the Variable Infiltration Capacity (VIC) land surface model, and a dynamic assimilation technique, a particle filter, to adjust the Tropical Rainfall Measuring Mission Multi-satellite Precipitation Analysis (TMPA) real-time precipitation estimates. We compare updated precipitation with real-time precipitation before and after adjustment and with NLDAS gauge-radar observations. Results show that satellite soil moisture retrievals provide additional information by correcting errors in rainfall bias. High accuracy soil moisture retrievals, when merged with precipitation, generally increase both rainfall frequency and intensity, and are most effective in the correction of rainfall under dry to normal surface condition while limited/negative improvement is seen over wet/saturated surfaces. Errors from soil moisture, mixed among the real signal, may generate a false rainfall signal approximately 2 mm day-1 and thus lower the precipitation accuracy after adjustment.

  17. Land Mobile Satellite Systems (LMSS): Single aperture system design

    NASA Technical Reports Server (NTRS)

    Weber, W. J., III

    1982-01-01

    The large size of the UHF antenna on the satellite provides two advantages with respect to the Land Mobile Satellite System design. It provides tremendous gain for both transmitting and receiving at the satellite and enables very simple, low power equipment in the mobile vehicle. The UHF antenna for this study was selected to have an aperture of 55 meters. This implies a beamwidth of roughly 0.45 degree and requires 87 beams to cover the continental United States.

  18. Satellite Power System (SPS) military implications

    NASA Technical Reports Server (NTRS)

    Bain, C. N.

    1978-01-01

    The military implications of the reference satellite power system (SPS) were examined is well as important military related study tasks. Primary areas of investigation were the potential of the SPS as a weapon, for supporting U.S. military preparedness, and for affecting international relations. In addition, the SPS's relative vulnerability to overt military action, terrorist attacks, and sabotage was considered.

  19. System specification for the reusable reentry satellite

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The RRS design shall provide a relatively inexpensive method of access to micro and fractional gravity space environments for an extended period of time, with eventual intact recovery on the surface of the Earth. This specification establishes the performance, design, development, and test requirements for the Reusable Reentry Satellite (RRS) system.

  20. Speculative histories of the Uranian satellite system

    NASA Astrophysics Data System (ADS)

    Peale, S. J.

    1988-05-01

    The hypothetical histories presently considered for the Uranian satellite system are very sensitive to the assumed satellite masses, within the errors of their determinations, as well as to the Uranian tidal effective dissipation function. A determination is made of the resonances that could have been encountered in these histories, and of the orbital eccentricity constraints that would have led to certain capture. It is found that if the mass of Miranda were of the upper extreme value, it would have been locked in a long-term 2/1 orbital resonance with Ariel to form a Laplacelike, three-body resonance that encompassed Umbriel.

  1. Satellite Power System (SPS) military applications

    NASA Technical Reports Server (NTRS)

    Ozeroff, M. J.

    1978-01-01

    The potential military role, both offensive and defensive, of a Satellite Power System (SPS) is examined. A number of potential military support possibilities are described. An SPS with military capabilities may have a strong negative impact on international relations if it is not internationalized. The SPS satellite would be vulnerable to military action of an enemy with good space capability, but would experience little or no threat from saboteurs or terrorists, except via the ground controls. The paper concludes with an outline of some of the key issues involved, and a number of recommendations for future study, including some areas for long term efforts.

  2. Distributed Satellite Communication System Design: First-Order Interactions between System and Network

    E-print Network

    de Weck, Olivier L.

    Distributed Satellite Communication System Design: First-Order Interactions between System to bankruptcy. The upfront capital required to implement a satellite communications system is staggering and performance of a system. Traditionally, the first step toward designing satellite communication systems

  3. Satellite sound broadcasting system, portable reception

    NASA Technical Reports Server (NTRS)

    Golshan, Nasser; Vaisnys, Arvydas

    1990-01-01

    Studies are underway at JPL in the emerging area of Satellite Sound Broadcast Service (SSBS) for direct reception by low cost portable, semi portable, mobile and fixed radio receivers. This paper addresses the portable reception of digital broadcasting of monophonic audio with source material band limited to 5 KHz (source audio comparable to commercial AM broadcasting). The proposed system provides transmission robustness, uniformity of performance over the coverage area and excellent frequency reuse. Propagation problems associated with indoor portable reception are considered in detail and innovative antenna concepts are suggested to mitigate these problems. It is shown that, with the marriage of proper technologies a single medium power satellite can provide substantial direct satellite audio broadcast capability to CONUS in UHF or L Bands, for high quality portable indoor reception by low cost radio receivers.

  4. An automated mapping satellite system ( Mapsat).

    USGS Publications Warehouse

    Colvocoresses, A.P.

    1982-01-01

    The favorable environment of space permits a satellite to orbit the Earth with very high stability as long as no local perturbing forces are involved. Solid-state linear-array sensors have no moving parts and create no perturbing force on the satellite. Digital data from highly stabilized stereo linear arrays are amenable to simplified processing to produce both planimetric imagery and elevation data. A satellite imaging system, called Mapsat, including this concept has been proposed to produce data from which automated mapping in near real time can be accomplished. Image maps as large as 1:50 000 scale with contours as close as a 20-m interval may be produced from Mapsat data. -from Author

  5. Role of light satellites in the high-resolution Earth observation domain

    NASA Astrophysics Data System (ADS)

    Fishman, Moshe

    1999-12-01

    Current 'classic' applications using and exploring space based earth imagery are exclusive, narrow niche tailored, expensive and hardly accessible. On the other side new, inexpensive and widely used 'consumable' applications will be only developed concurrently to the availability of appropriate imagery allowing that process. A part of these applications can be imagined today, like WWW based 'virtual tourism' or news media, but the history of technological, cultural and entertainment evolution teaches us that most of future applications are unpredictable -- they emerge together with the platforms enabling their appearance. The only thing, which can be ultimately stated, is that the definitive condition for such applications is the availability of the proper imagery platform providing low cost, high resolution, large area, quick response, simple accessibility and quick dissemination of the raw picture. This platform is a constellation of Earth Observation satellites. Up to 1995 the Space Based High Resolution Earth Observation Domain was dominated by heavy, super-expensive and very inflexible birds. The launch of Israeli OFEQ-3 Satellite by MBT Division of Israel Aircraft Industries (IAI) marked the entrance to new era of light, smart and cheap Low Earth Orbited Imaging satellites. The Earth Resource Observation System (EROS) initiated by West Indian Space, is based on OFEQ class Satellites design and it is capable to gather visual data of Earth Surface both at high resolution and large image capacity. The main attributes, derived from its compact design, low weight and sophisticated logic and which convert the EROS Satellite to valuable and productive system, are discussed. The major advantages of Light Satellites in High Resolution Earth Observation Domain are presented and WIS guidelines featuring the next generation of LEO Imaging Systems are included.

  6. Propagation considerations in satellite communication systems

    NASA Astrophysics Data System (ADS)

    Brussaard, Gert; Rogers, David V.

    1990-07-01

    Radio wave propagation phenomena that affect the performance of satellite communication systems are concisely discussed to introduce some topics in propagation research related to satellite systems design and to illustrate related problems and uncertainties. The focus is on troposphere effects. A summary of relevant propagation impairments is supplied, and general classes of impairments, the physical cause of each, and the major importance of each for sattelite systems are given Some impairments in the table are critically important of each for certain systems applications. For example, attenuation due to rainfall can be substantial for significant percentages of the time on 30/20-GHz propagation paths and will be the dominant path impairment for most Ka-band systems. Appropriate literature sources are referenced for the additional details that will be required for many applications.

  7. Space telemetric panomorph imaging system for micro/nano satellite

    NASA Astrophysics Data System (ADS)

    Thibault, Simon; Harvey, Eric

    2008-04-01

    For many years, many microsatellites (satellites in the 10-100 kg mass range) and nanosatellites (in the 1-10 kg mass range) missions have been designed, built and launched having the objective of technology demonstration. Recently, due to the advance of technologies over the past decade, a new trend is to use them in more demanding space missions such as space science, earth observation, flying formation and space surveillance. In micro/nano satellites applications, the need for size, mass, power consumption and cost reduction is critical. This is why there is an effort toward the development of specialized and integrated hardware. Among space hardware for satellites, the development of optical imaging payload and miniaturized attitude sensors are of great interest for space surveillance and space science applications. We proposed the development of a panomorph lens optical module designed to record wide and broadband images of a panoramic scene around the satellite. A key requirement of the optical module is therefore to be able to manage the field coverage properties to distinguish true element that can be used for star tracking, earth horizon sensing and related tracking functionalities. The optical module must provide all usable telemetric information for the satellite. The proposed technology consists of a concept of space telemetric imaging system, which will combine optically imaging for surveillance/visual monitoring of space and attitude determination capabilities in one compact and low-power consumption device for micro/nano satellite applications.

  8. Applications systems verification and transfer project. Volume 7: Cost/benefit analysis for the ASVT on operational applications of satellite snow-cover observations

    NASA Technical Reports Server (NTRS)

    Castruccio, P.; Loats, H.; Lloyd, D.; Newman, P.

    1981-01-01

    The results of the OASSO ASVT's were used to estimate the benefits accruing from the added information available from satellite snowcover area measurement. Estimates of the improvement in runoff prediction due to addition of SATSCAM were made by the Colorado ASVT personnel. The improvement estimate is 6-10%. Data were applied to subregions covering the Western States snow area amended by information from the ASVT and other watershed experts to exclude areas which are not impacted by snowmelt runoff. Benefit models were developed for irrigation and hydroenergy uses. The benefit/cost ratio is 72:1. Since only two major benefit contributors were used and since the forecast improvement estimate does not take into account future satellite capabilities these estimates are considered to be conservative. The large magnitude of the benefit/cost ratio supports the utility and applicability of SATSCAM.

  9. Fast Emission Estimates in China Constrained by Satellite Observations (Invited)

    NASA Astrophysics Data System (ADS)

    Mijling, B.; van der A, R.

    2013-12-01

    Emission inventories of air pollutants are crucial information for policy makers and form important input data for air quality models. Unfortunately, bottom-up emission inventories, compiled from large quantities of statistical data, are easily outdated for an emerging economy such as China, where rapid economic growth changes emissions accordingly. Alternatively, top-down emission estimates from satellite observations of air constituents have important advantages of being spatial consistent, having high temporal resolution, and enabling emission updates shortly after the satellite data become available. Constraining emissions from concentration measurements is, however, computationally challenging. Within the GlobEmission project of the European Space Agency (ESA) a new algorithm has been developed, specifically designed for fast daily emission estimates of short-lived atmospheric species on a mesoscopic scale (0.25 × 0.25 degree) from satellite observations of column concentrations. The algorithm needs only one forward model run from a chemical transport model to calculate the sensitivity of concentration to emission, using trajectory analysis to account for transport away from the source. By using a Kalman filter in the inverse step, optimal use of the a priori knowledge and the newly observed data is made. We apply the algorithm for NOx emission estimates in East China, using the CHIMERE model together with tropospheric NO2 column retrievals of the OMI and GOME-2 satellite instruments. The observations are used to construct a monthly emission time series, which reveal important emission trends such as the emission reduction measures during the Beijing Olympic Games, and the impact and recovery from the global economic crisis. The algorithm is also able to detect emerging sources (e.g. new power plants) and improve emission information for areas where proxy data are not or badly known (e.g. shipping emissions). The new emission estimates result in a better agreement between observations and simulations of air pollutant concentrations, facilitating improved air quality forecasts. The EU project MarcoPolo will combine these emission estimates from space with statistical information on e.g. land use, population density and traffic to construct a new up-to-date emission inventory for China.

  10. Sensitivity of satellite microwave and infrared observations to soil moisture at a global scale

    E-print Network

    Aires, Filipe

    Sensitivity of satellite microwave and infrared observations to soil moisture at a global scale: Relationship of satellite observations to in situ soil moisture measurements Catherine Prigent,1 Filipe Aires,2 of the sensitivity of the available satellite observations to in situ soil moisture measurements. Although none

  11. Astrometric positions for 18 irregular satellites of giant planets from 23 years of observations

    E-print Network

    Gomes-Júnior, A R; Vieira-Martins, R; Arlot, J -E; Camargo, J I B; Braga-Ribas, F; Neto, D N da Silva; Andrei, A H; Dias-Oliveira, A; Morgado, B E; Benedetti-Rossi, G; Duchemin, Y; Desmars, J; Lainey, V; Thuillot, W

    2015-01-01

    The irregular satellites of the giant planets are believed to have been captured during the evolution of the solar system. Knowing their physical parameters, such as size, density, and albedo is important for constraining where they came from and how they were captured. The best way to obtain these parameters are observations in situ by spacecrafts or from stellar occultations by the objects. Both techniques demand that the orbits are well known. We aimed to obtain good astrometric positions of irregular satellites to improve their orbits and ephemeris. We identified and reduced observations of several irregular satellites from three databases containing more than 8000 images obtained between 1992 and 2014 at three sites (Observat\\'orio do Pico dos Dias, Observatoire de Haute-Provence, and European Southern Observatory - La Silla). We used the software PRAIA (Platform for Reduction of Astronomical Images Automatically) to make the astrometric reduction of the CCD frames. The UCAC4 catalog represented the Inte...

  12. A computer system for geosynchronous satellite navigation

    NASA Technical Reports Server (NTRS)

    Koch, D. W.

    1980-01-01

    A computer system specifically designed to estimate and predict Geostationary Operational Environmental Satellite (GOES-4) navigation parameters using Earth imagery is described. The estimates are needed for spacecraft maneuvers while prediction provide the capability for near real-time image registration. System software is composed of four functional subsystems: (1) data base management; (2) image processing; (3) navigation; and (4) output. Hardware consists of a host minicomputer, a cathode ray tube terminal, a graphics/video display unit, and associated input/output peripherals. System validity is established through the processing of actual imagery obtained by sensors on board the Synchronous Meteorological Satellite (SMS-2). Results indicate the system is capable of operationally providing both accurate GOES-4 navigation estimates and images with a potential registration accuracy of several picture elements (pixels).

  13. Mutual Events in the Uranian satellite system in 2007

    NASA Astrophysics Data System (ADS)

    Arlot, J. E.

    2008-09-01

    The equinox time on the giant planets When the Sun crosses the equatorial plane of a giant planet, it is the equinox time occurring every half orbit of the planet, i.e. every 6 years for Jupiter, 14 years for Saturn, 42 years for Uranus and 82 years for Neptune. Except Neptune, each planet have several major satellites orbiting in the equatorial plane, then, during the equinox time, the satellites will eclipse each other mutually. Since the Earth follows the Sun, during the equinox time, a terrestrial observer will see each satellite occulting each other during the same period. These events may be observed with photometric receivers since the light from the satellites will decrease during the events. The light curve will provide information on the geometric configuration of the the satellites at the time of the event with an accuracy of a few kilometers, not depending on the distance of the satellite system. Then, we are able to get an astrometric observation with an accuracy several times better than using direct imaging for positions. Equinox on Uranus in 2007 In 2007, it was equinox time on Uranus. The Sun crossed the equatorial plane of Uranus on December 6, 2007. Since the opposition Uranus-Sun was at the end of August 2007, observations were performed from May to December 2007. Since the declination of Uranus was between -5 and -6 degrees, observations were better to make in the southern hemisphere. However, some difficulties had to be solved: the faintness of the satellites (magnitude between 14 and 16), the brightness of the planet (magnitude 5) making difficult the photometric observation of the satellites. The used of K' filter associated to a large telescope allows to increase the number of observable events. Dynamics of the Uranian satellites One of the goals of the observations was to evaluate the accuracy of the current dynamical models of the motion of the satellites. This knowledge is important for several reasons: most of time the Uranian system is observed "pole-on" and the relative inclinations of the orbits of the satellites are very difficult to know. More, this knowledge should allow us to determine the precession of Uranus which is not yet known. Another reason to improve the dynamics of the Uranian satellites is to quantify the dissipation of energy inside the satellites because of the tides: only very accurate astrometric observations may allow to reach such a result. We used two models for our purpose: the one from Laskar and Jacobson (GUST86) based upon observations made using observations made from 1911 to 1986 [1] and the one from Arlot, Lainey and Thuillot (LA06) [2] based upon a different sets of observations made from 1950 to 2006. Astrometric observations Since the mutual events are observable only every 42 years (in fact, 2007 was the first time where mutual events were observed on the Uranian system), many other astrometric observations were performed, mainly with photographic plates, CCD targets or using a meridian transit circle. These observations and their accuracy will be compared with mutual events. Note that these observations introduce some biases in the data (date of the opposition, absolute position of the planet), different than those of mutual events (equinox time). Observations of mutual events in 2007 Due to the difficulty of the observations, very few observations were made: about 15 events were observed using telescopes with apertures from 40 cm to 8 meters... The observing sites which reported observations were Marseille and Pic du Midi (France), Canarian Islands (Spain), La Silla and Paranal (Chile), Itajuba (Brazil), Tubitak (Turkey), Hanle (India) and Siding Spring (Australia). A preliminary analysis Some light curves were reduced and a comparison has been made with the theoretical calculations of the events. A preliminary analysis shows that LA06 has smaller residuals in the longitudes of the satellites than GUST86 but the residuals are equivalent in latitude. This confirms the problem due to the "pole-on" observation of this system and shows the

  14. Satellite remote sensing using direct receiving system: a conceptual study for satellite marine pollution monitoring

    NASA Astrophysics Data System (ADS)

    Tokumaru, Kumon

    2003-05-01

    A specially designed satellite receiving system for NOAA/AVHRR and FY-1C/MVISR started its operation in March 2002 at NPEC (Northwest Pacific Region Environmental Corporation Center, Toyama, Japan) envisaging the remote sensing application for marine pollution monitoring. While NOAA series and FY-1C/D are meteorological satellites and not marine pollution monitoring satellites, they are operational. By operating direct receiving system, we became privileged user like satellite owners and, in order to overview its feasibility, effectiveness or constraints, we implemented a conceptual analysis of overall space/ground system for satellite marine pollution monitoring.

  15. Satellite-based Observation of the Tectonics of Southern Tibet

    SciTech Connect

    Ryerson, F J; Finkel, R; van der Woerd, J

    2003-02-06

    The Himalayas and the Tibetan Plateau were formed as a result of the collision of India and Asia, and provide an excellent natural laboratory for the investigation of the mechanical response of the outer 100 km of the Earth (the lithosphere) to tectonic stress. Geophysicists are divided in their views on the nature of this response with one group advocating homogeneously distributed deformation in which the lithosphere deforms as a fluid continuum while others contend that deformation is highly localized with the lithosphere deforming as a system of rigid blocks. These rigid blocks or plate undergo little internal deformation. The latter group draws support from the high slip-rates recently observed on strike-slip faults along the northern edge of the Plateau (the Altyn Tagh Fault, ATF), coupled with seismic observations suggesting that these faults penetrate the entire lithosphere. These ''lithospheric faults'' define continental lithospheric plates and facilitate the eastward extrusion of the ''central Tibet plate''. If extrusion of a rigid Tibet occurs then there must be equivalent features at its southern boundary with slip-rates similar to those in the north. The southern boundary of Tibet, defined by the Main Himalayan Thrust (MHT), has no lateral component of motion and is therefore kinematically incompatible with motion in the north. However, a series of features, the Karakorum Fault, the Karakorum-Jiali Fracture Zone (KJFZ), the Jiali Fault and the Red River Fault which lie to the north of the MHT may define the actual, kinematic, southern boundary of this ''central Tibet plate''. We have investigated the rate of slip along the Karakorum Fault (KKF), the major strike-slip fault in southwestern Tibet. If the KKF represents the actual, kinematic, southern boundary of this Tibet, and is the only feature accommodating eastward extrusion of Tibet, then its slip-rate should be similar to that of the ATF in the north. Offsets along the Karakorum Fault ranging from tens of meters to kilometers have been mapped using satellite imagery and field mapping, and samples ages determined by cosmic-ray exposure dating. Near Bulong Kol (39{sup o}N, 75{sup o}E) cosmogenic dating of a 40 m fluvial offset yields a slip rate of {approx}6.5 mm/yr. Near Mt. Kailas (31.5{sup o}N, 80.7{sup o}E), a glacial moraine offset by {approx}350 m has been dated at 32.3 {+-} 9.5 thousand years, yielding a slip rate of 10.8 {+-} 3.6 mm/yr. In the Gar Valley (32{sup o}N, 80{sup o}E) a river channel incised in glacial sediments yields an offset of 1750 m and an age of 283,000 years equivalent to a slip-rate of 6 mm/yr. Relative to the ATF, the slip rates on the KKF are lower than expected, and since these measurements cover almost the entire length of the KKF, the disparity cannot be attributed to along strike variation in the rate. Based upon the analysis of satellite images along the Karakorum Fault, we believe that this apparent slip deficit may be to the en echelon arrangement of multiple strike slip fault segments that characterize what should more appropriately be called the Karakorum Fault Zone. The geometric arrangement of parallel fault segments produces the ''pull apart'' basins that form the valleys along the KKF. Hence, at any given latitude, slip along the KKF may be distributed among numerous fault segments. This investigation supports efforts to understand the structure and mechanical response of the Earth's crust and supports the application of remote sensing methods.

  16. Development status of Japanese Advanced Land Observing Satellite-2

    NASA Astrophysics Data System (ADS)

    Arikawa, Yoshihisa; Osawa, Yuji; Hatooka, Yasushi; Suzuki, Shinichi; Kankaku, Yukihiro

    2010-10-01

    The Advanced Land Observing Satellite-2 (ALOS-2) is a follow-on mission from ALOS "Daichi". The state-of-the-art L-band Synthetic Aperture Radar (SAR) aboard ALOS-2 will, in response to society's needs, have enhanced performance compared to ALOS/PALSAR. ALOS-2 will have a spotlight mode (1 and 3 m) and a high-resolution mode (3 to 10 m), while PALSAR has 10m resolution. The Preliminary Design was completed in March, 2010. Phase C/D has been started and the Engineering Models are currently under development. This paper describes the current development status of ALOS-2.

  17. Advanced technology for satellite data collection systems

    NASA Technical Reports Server (NTRS)

    Cote, C. E.; Painter, J. E.

    1981-01-01

    Technological developments in satellite data collection are aimed at relieving constraints of existing systems to permit expanded capability at lower costs in future operations. Constraints imposed by the limited electromagnetic spectrum available in the UHF band and the cost of user equipment are principal targets for improvement through technology. This paper describes ongoing developmental activities in system and component areas which will become available for the next generation of operations.

  18. Satellite Observations of Desert Dust-induced Himalayan Snow Darkening

    NASA Technical Reports Server (NTRS)

    Gautam, Ritesh; Hsu, N. Christina; Lau, William K.-M.; Yasunari, Teppei J.

    2013-01-01

    The optically thick aerosol layer along the southern edge of the Himalaya has been subject of several recent investigations relating to its radiative impacts on the South Asian summer monsoon and regional climate forcing. Prior to the onset of summer monsoon, mineral dust from southwest Asian deserts is transported over the Himalayan foothills on an annual basis. Episodic dust plumes are also advected over the Himalaya, visible as dust-laden snow surface in satellite imagery, particularly in western Himalaya. We examined spectral surface reflectance retrieved from spaceborne MODIS observations that show characteristic reduction in the visible wavelengths (0.47 nm) over western Himalaya, associated with dust-induced solar absorption. Case studies as well as seasonal variations of reflectance indicate a significant gradient across the visible (0.47 nm) to near-infrared (0.86 nm) spectrum (VIS-NIR), during premonsoon period. Enhanced absorption at shorter visible wavelengths and the resulting VIS-NIR gradient is consistent with model calculations of snow reflectance with dust impurity. While the role of black carbon in snow cannot be ruled out, our satellite-based analysis suggests the observed spectral reflectance gradient dominated by dust-induced solar absorption during premonsoon season. From an observational viewpoint, this study underscores the importance of mineral dust deposition toward darkening of the western Himalayan snow cover, with potential implications to accelerated seasonal snowmelt and regional snow albedo feedbacks.

  19. Surface topography estimated by inversion of satellite gravity gradiometry observations

    NASA Astrophysics Data System (ADS)

    Ramillien, Guillaume

    2015-04-01

    An integration of mass elements is presented for evaluating the six components of the 2-order gravity tensor (i.e., second derivatives of the Newtonian mass integral for the gravitational potential) created by an uneven sphere topography consisting of juxtaposed vertical prisms. The method is based on Legendre polynomial series with the originality of taking elastic compensation of the topography by the Earth's surface into account. The speed of computation of the polynomial series increases logically with the observing altitude from the source of anomaly. Such a forward modelling can be easily used for reduction of observed gravity gradient anomalies by the effects of any spherical interface of density. Moreover, an iterative least-square inversion of the observed gravity tensor values ??? is proposed to estimate a regional set of topographic heights. Several tests of recovery have been made by considering simulated gradiometry anomaly data, and for varying satellite altitudes and a priori levels of accuracy. In the case of GOCE-type gradiometry anomalies measured at an altitude of ~300 km, the search converges down to a stable and smooth topography after 20-30 iterations while the final r.m.s. error is ~100 m. The possibility of cumulating satellite information from different orbit geometries is also examined for improving the prediction.

  20. Networks for Autonomous Formation Flying Satellite Systems

    NASA Technical Reports Server (NTRS)

    Knoblock, Eric J.; Konangi, Vijay K.; Wallett, Thomas M.; Bhasin, Kul B.

    2001-01-01

    The performance of three communications networks to support autonomous multi-spacecraft formation flying systems is presented. All systems are comprised of a ten-satellite formation arranged in a star topology, with one of the satellites designated as the central or "mother ship." All data is routed through the mother ship to the terrestrial network. The first system uses a TCP/lP over ATM protocol architecture within the formation the second system uses the IEEE 802.11 protocol architecture within the formation and the last system uses both of the previous architectures with a constellation of geosynchronous satellites serving as an intermediate point-of-contact between the formation and the terrestrial network. The simulations consist of file transfers using either the File Transfer Protocol (FTP) or the Simple Automatic File Exchange (SAFE) Protocol. The results compare the IF queuing delay, and IP processing delay at the mother ship as well as application-level round-trip time for both systems, In all cases, using IEEE 802.11 within the formation yields less delay. Also, the throughput exhibited by SAFE is better than FTP.

  1. Cooling systems for satellite remote sensing instrumentation

    NASA Technical Reports Server (NTRS)

    Copeland, R. J.; Oren, J. A.

    1974-01-01

    The characteristics of a cryogenic cooling system for the Pollution Monitoring Satellite (PMS) are discussed. Studies were conducted to make the following determinations: (1) the characteristics and use of proven and state-of-the-art cryogenic cooling systems for six specified ranges of performance, (2) the system most applicable for each of the six cooling categories, and (3) conceptual designs for candidate system for each of the six representative cooling categories. The six cooling categories of electrical loads are defined. The desired mission life for the cooling system is two years with both continuous and intermittent operating conditions.

  2. Solar power satellite system definition study, volume 7

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Guidelines and assumptions used in the design of a system of geosynchronous satellites for transmitting solar power to earth were discussed as well as the design evolutions of the principle types of solar power satellites and space support systems.

  3. STABILITY OF SATELLITES IN CLOSELY PACKED PLANETARY SYSTEMS

    E-print Network

    Payne, Matthew J.

    We perform numerical integrations of four-body (star, planet, planet, satellite) systems to investigate the stability of satellites in planetary systems with tightly packed inner planets (STIPs). We find that the majority ...

  4. On the accuracy of longwave fluxes estimated from satellite IR window radiance observations

    NASA Astrophysics Data System (ADS)

    Ohring, G.; Gruber, A.; Ellingson, R. G.

    The NOAA polar orbiting satellites' scanning radiometer (SR) and Advanced Very High Resolution Radiometer (AVHRR) have been used to monitor the earth-atmosphere system's radiation budget, on the basis of the high correlation between narrow and broad band radiation observations. The total longwave flux to space is obtained from the IR window observations through the application of a regression relationship that is based on the computer simulations of Abel and Gruber (1979).

  5. Satellite observation and mapping of wintertime ozone variability in the lower stratosphere

    NASA Technical Reports Server (NTRS)

    Geller, M. A.; Chi, Yuechen; Rood, R. B.; Douglass, A. R.; Kaye, J. A.; Allen, D. J.

    1993-01-01

    Comparison is made between 30 mbar ozone fields that are generated by a transport chemistry model utilizing the winds from the Goddard Space Flight Center stratospheric data assimilation system (STRATAN), observations from the LIMS instrument on Nimbus-7, and the ozone fields that result from 'flying' a mathematical simulation of LIMS observations through the transport chemistry model ozone fields. The modeled ozone fields were found to resemble the LIMS observations, but the model fields show much more temporal and spatial structure than do the LIMS observations. The 'satellite mapped' model results resemble the LIMS observations much more closely. These results are very consistent with the earlier discussions of satellite space-time sampling by Salby.

  6. Satellite Situation Center data system for magnetospheric science planning

    SciTech Connect

    Aist-Sagara, L.; Cooper, J.F.; Mcguire, R.E.; Parthasarathy, R.; Peredo, M.

    1995-01-01

    Critical problems in planning coordinated observation campaigns for magnetospheric science include the need to predict time intervals when one or more observing satellites or ground stations will be connected along magnetic field lines to other observation sites, or when such sites will be located within magnetospheric regions of common interest. The Satellite Situation Center (SSC) was created at the National Space Science Data Center (NSSDC) during the International Magnetospheric Study in the 1970s to address these problems. The SSC Data System has evolved since that era to support potentially complex queries by SSC staff and has now been opened to NASA Science Internet access via the NSSDC On-line Data Information System (NODIS). The SSC software, ephemeris data base, and access modes are described for the Version 2.1 release in 1993.

  7. Maui Space Surveillance System Satellite Categorization Laboratory

    NASA Astrophysics Data System (ADS)

    Deiotte, R.; Guyote, M.; Kelecy, T.; Hall, D.; Africano, J.; Kervin, P.

    The MSSS satellite categorization laboratory is a fusion of robotics and digital imaging processes that aims to decompose satellite photometric characteristics and behavior in a controlled setting. By combining a robot, light source and camera to acquire non-resolved images of a model satellite, detailed photometric analyses can be performed to extract relevant information about shape features, elemental makeup, and ultimately attitude and function. Using the laboratory setting a detailed analysis can be done on any type of material or design and the results cataloged in a database that will facilitate object identification by "curve-fitting" individual elements in the basis set to observational data that might otherwise be unidentifiable. Currently the laboratory has created, an ST-Robotics five degree of freedom robotic arm, collimated light source and non-focused Apogee camera have all been integrated into a MATLAB based software package that facilitates automatic data acquisition and analysis. Efforts to date have been aimed at construction of the lab as well as validation and verification of simple geometric objects. Simple tests on spheres, cubes and simple satellites show promising results that could lead to a much better understanding of non-resolvable space object characteristics. This paper presents a description of the laboratory configuration and validation test results with emphasis on the non-resolved photometric characteristics for a variety of object shapes, spin dynamics and orientations. The future vision, utility and benefits of the laboratory to the SSA community as a whole are also discussed.

  8. Modeling Prairie Pothole Lakes: Linking Satellite Observation and Calibration (Invited)

    NASA Astrophysics Data System (ADS)

    Schwartz, F. W.; Liu, G.; Zhang, B.; Yu, Z.

    2009-12-01

    This paper examines the response of a complex lake wetland system to variations in climate. The focus is on the lakes and wetlands of the Missouri Coteau, which is part of the larger Prairie Pothole Region of the Central Plains of North America. Information on lake size was enumerated from satellite images, and yielded power law relationships for different hydrological conditions. More traditional lake-stage data were made available to us from the USGS Cottonwood Lake Study Site in North Dakota. A Probabilistic Hydrologic Model (PHM) was developed to simulate lake complexes comprised of tens-of-thousands or more individual closed-basin lakes and wetlands. What is new about this model is a calibration scheme that utilizes remotely-sensed data on lake area as well as stage data for individual lakes. Some ¼ million individual data points are used within a Genetic Algorithm to calibrate the model by comparing the simulated results with observed lake area-frequency power law relationships derived from Landsat images and water depths from seven individual lakes and wetlands. The simulated lake behaviors show good agreement with the observations under average, dry, and wet climatic conditions. The calibrated model is used to examine the impact of climate variability on a large lake complex in ND, in particular, the “Dust Bowl Drought” 1930s. This most famous drought of the 20th Century devastated the agricultural economy of the Great Plains with health and social impacts lingering for years afterwards. Interestingly, the drought of 1930s is unremarkable in relation to others of greater intensity and frequency before AD 1200 in the Great Plains. Major droughts and deluges have the ability to create marked variability of the power law function (e.g. up to one and a half orders of magnitude variability from the extreme Dust Bowl Drought to the extreme 1993-2001 deluge). This new probabilistic modeling approach provides a novel tool to examine the response of the behavior of a complex of closed lakes vary in scale from the footprint of a small house to that of a small city.

  9. Satellite observations support to disaster monitoring: the operational use of COSMO-SkyMed constellation

    NASA Astrophysics Data System (ADS)

    Candela, Laura; Cardaci, Chiara; Coletta, Alessandro; Corina, Angela; Di Bucci, Daniela; Giuliani, Roberta; Pagliara, Paola; Zoffoli, Simona; Boni, Giorgio

    2013-04-01

    The aim of this work is to show some experiences recently made by ASI and DPC, with the collaboration of Italian research institutes and academies, in using satellite observations to monitor different steps of emergency management in Italy: the 2012 Emilia earthquakes and the 2012 seismic sequence in the Mt. Pollino area, the volcano Stromboli eruption, the floods occurred in Tuscany and Lazio. The effectiveness of the satellite observations contribution to the disaster management is to day in phase of demonstration, and the encouraging results obtained up to now rely not only on the maturity of the data processing and interpretation techniques (more exploited), but also on the coordination in accessing and programming satellites systems. During the past year, COSMO-SkyMed has been successfully used to acquire, in very short times, high quality images of disaster areas. When the emergency evolution made it necessary, after the set up the monitoring service went on several months. Our experience confirmed how important is the availability of consistent series of satellite data, acquired on disaster prone areas in order to enable and facilitate post-disaster activities. Moreover, some results have been made possible thanks to science oriented initiatives sponsored by ASI and to the long-lasting cooperation among DPC and the national research institutions. In general, to meet civil protection needs after a disaster, typical activities based on earth observation techniques, as rapid mapping, recovery and first evaluation of damage, require the following observation capabilities: • medium-to-high spatial resolution • high revisit time, coupled with large spatial and spectral coverage • night/daylight and all-weather observations • capability of very short response time and frequent revisit opportunities for the study area • availability of a good reference archive • access and provision of satellite data for operational purposes, based on well defined rules and procedures. The experience made shows how all these characteristics play a key role during real emergencies. Many players, each with its specific role but working as a single team, are involved in the emergency management: the Italian Space Agency, the national Department of Civil Protection, and the scientific institutions that are in charge to elaborate and interpret satellite data. The work done up to now shows the importance of coordination for a sustained access to data source, in order to meet the requirements of the disaster monitoring and fully exploit the satellite system capabilities. This experience paves the way for a more effective and enlarged use of satellite observations in the civil protection domain.

  10. The Global Ocean Observing System

    NASA Technical Reports Server (NTRS)

    Kester, Dana

    1992-01-01

    A Global Ocean Observing System (GOOS) should be established now with international coordination (1) to address issues of global change, (2) to implement operational ENSO forecasts, (3) to provide the data required to apply global ocean circulation models, and (4) to extract the greatest value from the one billion dollar investment over the next ten years in ocean remote sensing by the world's space agencies. The objectives of GOOS will focus on climatic and oceanic predictions, on assessing coastal pollution, and in determining the sustainability of living marine resources and ecosystems. GOOS will be a complete system including satellite observations, in situ observations, numerical modeling of ocean processes, and data exchange and management. A series of practical and economic benefits will be derived from the information generated by GOOS. In addition to the marine science community, these benefits will be realized by the energy industries of the world, and by the world's fisheries. The basic oceanic variables that are required to meet the oceanic and predictability objectives of GOOS include wind velocity over the ocean, sea surface temperature and salinity, oceanic profiles of temperature and salinity, surface current, sea level, the extent and thickness of sea ice, the partial pressure of CO2 in surface waters, and the chlorophyll concentration of surface waters. Ocean circulation models and coupled ocean-atmosphere models can be used to evaluate observing system design, to assimilate diverse data sets from in situ and remotely sensed observations, and ultimately to predict future states of the system. The volume of ocean data will increase enormously over the next decade as new satellite systems are launched and as complementary in situ measuring systems are deployed. These data must be transmitted, quality controlled, exchanged, analyzed, and archived with the best state-of-the-art computational methods.

  11. Observations of the magnetosphere and ionosphere by Dynamics Explorer satellite. V - Unmanned operational system for receiving S-band signals from the DE-1

    NASA Astrophysics Data System (ADS)

    Yamamoto, Shin-Ichi; Sawada, Fumitake; Kasai, Katsuyuki

    1987-12-01

    During automatic reception of the DE-1 S-band signals by the Radio Research Laboratory station at Kashima (Japan), the telemetry receiver is often not phase-locked with the main carrier frequency (false lock), preventing the examination of the operational results without the use of human judgment. This paper describes an electronic circuit designed for receiving S-band signals from the DE-1 satellite, which avoids a false lock. Special consideration is given to the design considerations and an outline of the telemetry facilities improved for automatic unmanned operation.

  12. Anomalous event diagnosis for environmental satellite systems

    NASA Technical Reports Server (NTRS)

    Ramsay, Bruce H.

    1993-01-01

    The National Oceanic and Atmospheric Administration's (NOAA) National Environmental Satellite, Data, and Information Service (NESDIS) is responsible for the operation of the NOAA geostationary and polar orbiting satellites. NESDIS provides a wide array of operational meteorological and oceanographic products and services and operates various computer and communication systems on a 24-hour, seven days per week schedule. The Anomaly Reporting System contains a database of anomalous events regarding the operations of the Geostationary Operational Environmental Satellite (GOES), communication, or computer systems that have degraded or caused the loss of GOES imagery. Data is currently entered manually via an automated query user interface. There are 21 possible symptoms (e.g., No Data), and 73 possible causes (e.g., Sectorizer - World Weather Building) of an anomalous event. The determination of an event's cause(s) is made by the on-duty computer operator, who enters the event in a paper based daily log, and by the analyst entering the data into the reporting system. The determination of the event's cause(s) impacts both the operational status of these systems, and the performance evaluation of the on-site computer and communication operations contractor.

  13. Satellite observation of anomalous phytoplankton blooms in the Black Sea

    NASA Astrophysics Data System (ADS)

    Stanichny, Sergey; Stanychna, Rimma; Solovyov, Dmytro; Yasakova, Olga

    2013-04-01

    AVHRR, MODIS, MERIS, ASAR, ETM+ data were used for bloom detection in the Black Sea and investigation of phytoplankton impact on the water properties. Intensive blooms of the blue green algae were observed last years by satellite data in the north-western part of the Black Sea in summer season. Well detected in optical data blue - green algae affected on thermal properties of the sea upper layer too. Possible reason of the bloom occurrence and development are discussed. Summer coccolithophore bloom is typical for the Black Sea event, but duration and intensity of the bloom in May-July 2012 were unique and not observed earlier. Intercomparison of the satellite data with in situ biological measurements gave Emiliania huxleyi concentration more than 20*106 cells per liter in zones of the maximum bloom. Estimations of the coccolith concentration in water gave 4*10-3 g/liter. Total mass of the coccolith and related sediments during bloom period was higher than integral for the previous 15 years.

  14. Satellite Telemetry and Command using Big LEO Mobile Telecommunications Systems

    NASA Technical Reports Server (NTRS)

    Huegel, Fred

    1998-01-01

    Various issues associated with satellite telemetry and command using Big LEO mobile telecommunications systems are presented in viewgraph form. Specific topics include: 1) Commercial Satellite system overviews: Globalstar, ICO, and Iridium; 2) System capabilities and cost reduction; 3) Satellite constellations and contact limitations; 4) Capabilities of Globalstar, ICO and Iridium with emphasis on Globalstar; and 5) Flight transceiver issues and security.

  15. Indian Regional Navigation Satellites System (IRNSS) is the world's rst

    E-print Network

    Calgary, University of

    Indian Regional Navigation Satellites System (IRNSS) is the world's rst regional navigation system with its footprint primarily over the Indian subcontinent. The system is expected to have seven satellites satellite placing) available to the Indian Space Research Organization (ISRO), the agency responsible

  16. Evaluation of Long-Term Cloud-Resolving Model Simulations Using Satellite Radiance Observations and Multifrequency Satellite Simulators

    E-print Network

    Masunaga, Hirohiko

    Evaluation of Long-Term Cloud-Resolving Model Simulations Using Satellite Radiance Observations Three-Step Evaluation Framework (T3EF) for the systematic evaluation of precipitating cloud types and microphysics in a cloud-resolving model (CRM). T3EF utilizes multisensor satellite simulators and novel

  17. Aerosol Optical Depth from Satellite Observations during ACE-Asia

    NASA Astrophysics Data System (ADS)

    Nielsen, K. E.; Durkee, P. A.; Rocha, J.; Brown, B.

    2001-12-01

    Utilizing NOAA AVHRR, SeaWiFS and GMS-5 satellite-based measurements of the surface and atmosphere during ACE-Asia, we expect to better characterize the effects of dense (Gobi Desert) dust and anthropogenic (both biomass burning and industrial) aerosol plumes not observed during previous ACE campaigns. Further, characterization will be made of the complicated sea surface turbidities caused by enormous river outflows and other coastal effects. The observations made during ACE-Asia will allow us to better validate aerosol optical depth algorithms for the various aerosol types characteristic of the ACE-Asia experiment. Additionally, hourly GMS-5 imagery analysis proved useful during the experiment for monitoring and tracking elevated dust plumes as they formed over the continent and spread eastward toward the Pacific Ocean.

  18. South Atlantic anomaly filter for satellite UV observation

    NASA Astrophysics Data System (ADS)

    Niu, Jianguo; Flynn, Lawrence E.

    2011-10-01

    A South Atlantic Anomaly (SAA) filter has been developed to filter out large amounts of noise caused by high energy protons hitting onto the optical instrument focal plane when the satellite passes through the SAA region. The filter is based on the Principal Component Analysis (PCA)/Empirical Orthogonal Function (EOF) analysis. The EOF vectors derived from an orbit outside of the SAA region were used to represent the observations coming from the noisy SAA region. Then using the clear EOF vectors, the observations within SAA region are rebuilt with the most important principle components. The filter works well in UV region. Tests on L1B data from Global Ozone Monitoring Experiment-2 (GOME2) and Ozone Monitoring Instrument (OMI) have been conducted. It is expected that this filter can help to improve the measurements and retrievals for the Ozone Mapping and Profiler Suite (OMPS) nadir profiler in the SAA region.

  19. Satellite-observed characteristics of midwest severe thunderstorm anvils

    NASA Technical Reports Server (NTRS)

    Heymsfield, Gerald M.; Blackmer, Roy H., Jr.

    1988-01-01

    The cloud top and anvil structure of severe thunderstorms observed by the GOES satellite are analyzed for five SESAME cases in 1979 and four non-SESAME cases in 1980-1982. The data is compared with previous models and hypotheses, paying particular attention to the V feature and thermal couplets in the IR observations. The characteristics of the cases are examined and related to the upper-level temperature and wind conditions. It is found that the warm points downwind of the cloud top are due to subsidence. The anaylsis suggests the presence of subsidence due to mountainlike waves. A model in which the close-in warm point is produced by both internal cloud air motions and stratospheric flow around and over the cloud top. It is suggested that the distant warm point is due to either a wave perturbation from air flowing over the cloud top, or air flowing horizonatlly around the elevated portion of the cloud top and anvil.

  20. Satellite microwave observations of the Utah Great Salt Lake Desert

    NASA Technical Reports Server (NTRS)

    Ulaby, F. T.; Dellwig, L. F.; Schmugge, T. J.

    1975-01-01

    Microwave data acquired over the Great Salt Lake Desert by sensors aboard Skylab and Nimbus 5 indicate that microwave emission and backscatter were strongly influenced by contributions from subsurface layers of sediment saturated with brine. This phenomenon was observed by Skylab's S-194 radiometer operating at 1.4 GHz, S-193 RADSCAT (Radiometer-Scatterometer) operating at 13.9 GHz and the Nimbus 5 ESMR (Electrically Scanning Microwave Radiometer) operating at 19.35 GHz. The availability of ESMR data over an 18 month period allowed an investigation of temporal variations. Aircraft 1.4 GHz radiometer data acquired two days after one of the Skylab passes confirm the satellites observations. Data from the ESMR revealed similar responses over the Bolivian deserts, which have geologic features similar to those of the Utah desert.

  1. LCROSS: Lunar CRater Observation and Sensing Satellite Project

    NASA Technical Reports Server (NTRS)

    Marmie, John

    2010-01-01

    This slide presentation reviews the success of the Lunar Crater Observation and Sensing Satellite (LCROSS) project. The LCROSS mission science goals was to: (1) Confirm the presence or absence of water ice in a permanently shadowed region on the Moon (2) Identify the form/state of hydrogen observed by at the lunar poles (3) Quantify, if present, the amount of water in the lunar regolith, with respect to hydrogen concentrations (4) Characterize the lunar regolith within a permanently shadowed crater on the Moon. The mission confirmed the presence of water ice on the moon by impacting a part of the spent Centaur upper stage into the Cabeus crater.. The presentation includes pictures of the development of the spacecraft, testing, launch, impact site, impact and a section of what the author called "Lunacy" which showed joking cartoons.

  2. Satellite voice broadcase system study. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    Horstein, M.

    1985-01-01

    The feasibility of providing Voice of America (VOA) broadcasts by satellite relay was investigated. Satellite voice broadcast systems are described for three different frequency bands: HF, FHV, and L-band. Geostationary satellite configurations are considered for both frequency bands. A system of subsynchronous, circular satellites with an orbit period of 8 hours was developed for the HF band. The VHF broadcasts are provided by a system of Molniya satellites. The satellite designs are limited in size and weight to the capability of the STS/Centaur launch vehicle combination. At L-band, only four geostationary satellites are needed to meet the requirements of the complete broadcast schedule. These satellites are comparable in size and weight to current satellites designed for the direct broadcast of video program material.

  3. A Geostationary Satellite Constellation for Observing Global Air Quality: Status of the CEOS Activity

    NASA Astrophysics Data System (ADS)

    Al-Saadi, J. A.; Zehner, C.

    2011-12-01

    Several countries and space agencies are currently planning to launch geostationary satellites in the 2017-2022 time frame to obtain atmospheric composition measurements for characterizing anthropogenic and natural distributions of tropospheric ozone, aerosols, and their precursors, which are important factors in understanding air quality and climate change. While a single geostationary satellite can view only a portion of the globe, it is possible for a minimum of three geostationary satellites, positioned to view Europe/Middle East/Africa, Asia/Australasia, and the Americas, to collectively provide near-global coverage. Harmonizing the planned geostationary missions to be contemporaneous and have common observing capabilities and data distribution protocols would synergistically enable critically needed understanding of the interactions between regional and global atmospheric composition and of the implications for air quality and climate. Such activities would directly address societal benefit areas of the Global Earth Observation System of Systems (GEOSS), including Health, Energy, Climate, Disasters, and Ecosystems, and are responsive to the requirements of each mission to provide advanced user services and societal benefits. Over the past 2 years, the Atmospheric Composition Constellation (ACC) of the Committee on Earth Observation Satellites (CEOS) has developed a white paper describing such collaboration and the benefits to be derived from it. The resulting ACC recommendations were endorsed by CEOS in May 2011. Here we will present an update on collaborative activities and next steps. This presentation is envisioned to serve as an introduction to the oral sessions associated with Session A.25.

  4. Regional satellite systems - Required or redundant

    NASA Astrophysics Data System (ADS)

    Filep, R.

    1981-09-01

    It is shown that the development of such regional satellite systems as the Arab League's Arabsat, the South American Aseta, and the ASEAN nations' Palapa II, will be redundant if Intelsat moves ahead with its expanded service options with multiple frequency and beam configurations. Attention is given to direct broadcast satellite systems and the geostationary platform concept, which would incorporate C-band high-volume trunking, meteorological data relay, interplatform link, and Ku-band TV distribution and could be constructed in orbit by the Space Shuttle. The platform concept offers antenna reflectors that could be utilized by many 'feeds' or multiple-phase arrays, permitting frequency reuse many hundreds of times over.

  5. Subtropical Gyre Variability Observed by Ocean Color Satellites

    NASA Technical Reports Server (NTRS)

    McClain, Charles R.; Signorini, Sergio R.; Christian, James R.

    2002-01-01

    The subtropical gyres of the world are extensive, coherent regions that occupy about 40% of the surface of the earth. Once thought to be homogeneous and static habitats, there is increasing evidence that mid-latitude gyres exhibit substantial physical and biological variability on a variety of time scales. While biological productivity within these oligotrophic regions may be relatively small, their immense size makes their total contribution significant. Global distributions of dynamic height derived from satellite altimeter data, and chlorophyll concentration derived from satellite ocean color data, show that the dynamic center of the gyres, the region of maximum dynamic height where the thermocline is deepest, does not coincide with the region of minimum chlorophyll concentration. The physical and biological processes by which this distribution of ocean properties is maintained, and the spatial and temporal scales of variability associated with these processes, are analyzed using global surface chlorophyll-a concentrations, sea surface height, sea surface temperature and surface winds from operational satellite and meteorological sources, and hydrographic data from climatologies and individual surveys. Seasonal and interannual variability in the areal extent of the subtropical gyres are examined using 8 months (November 1996 - June 1997) of OCTS and nearly 5 years (September 1997 - June 02) of SeaWiFS ocean color data and are interpreted in the context of climate variability and measured changes in other ocean properties (i.e., wind forcing, surface currents, Ekman pumping, and vertical mixing). The North Pacific and North Atlantic gyres are observed to be shrinking over this period, while the South Pacific, South Atlantic, and South Indian Ocean gyres appear to be expanding.

  6. Single-satellite global positioning system

    NASA Astrophysics Data System (ADS)

    Bagrov, Alexander V.; Leonov, Vladislav A.; Mitkin, Alexander S.; Nasyrov, Alexander F.; Ponomarenko, Andreu D.; Pichkhadze, Konstantin M.; Sysoev, Valentin K.

    2015-12-01

    A new concept of a global positioning support system, based on only one satellite, was offered. Unlike all other GPS and GLONASS satellite systems that are in use, within the offered modification, all metrological support is provided by on-board measurements, which means, that it does not need any ground support of coordinate measurements or orbital characteristics of the satellite system. The cosmic-based angle-measuring instrument measures the arcs lengths between the measured ground-points, that are marked with light beacons, and navigation stars. Each measurement takes approximately 0.04 s, with the precision of 1 mm in recalculation to ground-relations. Long series of arc measurements between different objects on the ground and in the sky enable the solution of both determination of geodesic coordinates of the measured points and position of the spacecraft during the measuring process by using geodesic equation methods. In addition, it enables the qualification of the geopotential guaranties. The offered scheme will be used for the determination of the frame of selenocentric coordinates during the "Luna-Globe" and "Luna-Resource" missions for precise navigation of landing modules and maybe will be used for precise gridding of the Martian surface.

  7. Earth Observing System: Global Observations to Study the Earth's Environment

    NASA Technical Reports Server (NTRS)

    King, Michael D.

    2001-01-01

    The Earth Observing System (EOS) is a space-based observing system comprised of a series of satellite sensors by which scientists can monitor the Earth, a Data and Information System (EOSDIS) enabling researchers worldwide to access the satellite data, and an interdisciplinary science research program to interpret the satellite data. During the last couple of years, four EOS science missions were launched, representing observations of (1) total solar irradiance, (2) Earth radiation budget, (3) land cover & land use change, (4) ocean processes (vector wind, sea surface temperature, and ocean color), (5) atmospheric processes (aerosol and cloud properties, water vapor, and temperature and moisture profiles), and (6) tropospheric chemistry. In succeeding years many more satellites will be launched that will contribute immeasurably to our understanding of the Earth's environment. In this presentation I will describe how scientists are using NASA's Earth science data to examine land use and natural hazards, environmental air quality, including dust storms over the world's deserts, cloud and radiation properties, sea surface temperature, and winds over the ocean.

  8. The global Earth observation system of systems

    NASA Astrophysics Data System (ADS)

    Achache, José

    2010-05-01

    Recognizing the growing need for improved Earth observations, 140 governments and leading international organizations have established the Group on Earth Observations, or GEO, to collaborate and implement a Global Earth Observation System of Systems (GEOSS) by the year 2015. Countries and organizations are contributing their respective Earth monitoring systems, from satellites in space and in situ instruments on land, in the oceans and in the atmosphere. They are interlinking these systems so that, together, they provide a more complete picture of Earth's systems dynamics. GEO is developing common technical standards to pool observations and ensure their cross calibration and validation. It is building a web-based infrastructure to ensure easy access to the wealth of data and services contributed to, or generated by, GEOSS. GEO has been promoting the free and open sharing and dissemination of Earth observation data which has already driven significant changes in data distribution policies of several key Earth observing satellites: Landsat, Cbers and the future Sentinels of GMES. GEO is also reflecting on solutions to transition research systems into operational observing systems and ensure their long-term sustainability. First, the current status of GEOSS implementation and these core activities of GEO will be presented. Then, examples of global data sets and information systems or services developed through GEOSS will be presented: - a high-resolution global digital elevation model (DEM) based on Aster data was released by Japan and the USA. In situ measurements are now being used to improve the model as well as the stacking procedure used to develop it; - the Supersites initiative ensures coordinated access to data and information on natural hazards in geologically active regions. In light of the recent tragedy in Haiti, this project created a dedicated web site regularly updated with maps of seismicity, tectonics, Coulomb stress changes, topography, real and synthetic interferograms, as well as damage maps, data, and space images. See http://supersites.unavco.org/haiti.php; - the global carbon observation and analysis system combines observations, reanalysis and product development to provide regional information on emission variations. It addresses the three components of the carbon cycle (atmosphere, land, ocean). The project includes the improvement of global networks of atmospheric CO2 observations, air-surface exchange flux networks, surface ocean CO2 and related marine biochemistry observations, as well as space-based measurements combining Sciamachy , Airs and the newly launched Japanese Gosat; - the Forest Carbon Tracking (FCT) project coordinates the acquisition of observations from multi-spectral and radar (X, C and L-band) satellites, their processing through different models and methodologies and their validation by in situ measurements in 7 selected countries. The aim is to demonstrate the feasibility of a global monitoring and verification system for carbon storage and change in forests. Data and results can be viewed on-line at www.geo-fct.org. This portal allows users to visualize the FCT National Demonstrators, the relevant validation sites and the inventory of the coordinated acquisitions of satellite and in-situ data. Maps and information resulting from the processing of the data will also be posted here when available.

  9. Cloudsat and MTSAT Satellites Observer Atsani - Duration: 25 seconds.

    NASA Video Gallery

    This Aug. 19 image combines cloud imagery from Japan's MTSAT satellite and NASA's CloudSat satellite. Areas of pink and red designate larger amounts of liquid and ice. Light blue indicate smaller c...

  10. Antartic sea ice, 1973 - 1976: Satellite passive-microwave observations

    NASA Technical Reports Server (NTRS)

    Zwally, H. J.; Comiso, J. C.; Parkinson, C. L.; Campbell, W. J.; Carsey, F. D.; Gloersen, P.

    1983-01-01

    Data from the Electrically Scanning Microwave Radiometer (ESMR) on the Nimbus 5 satellite are used to determine the extent and distribution of Antarctic sea ice. The characteristics of the southern ocean, the mathematical formulas used to obtain quantitative sea ice concentrations, the general characteristics of the seasonal sea ice growth/decay cycle and regional differences, and the observed seasonal growth/decay cycle for individual years and interannual variations of the ice cover are discussed. The sea ice data from the ESMR are presented in the form of color-coded maps of the Antarctic and the southern oceans. The maps show brightness temperatures and concentrations of pack ice averaged for each month, 4-year monthly averages, and month-to-month changes. Graphs summarizing the results, such as areas of sea ice as a function of time in the various sectors of the southern ocean are included. The images demonstrate that satellite microwave data provide unique information on large-scale sea ice conditions for determining climatic conditions in polar regions and possible global climatic changes.

  11. An Examination of Intertidal Temperatures Through Remotely Sensed Satellite Observations

    NASA Astrophysics Data System (ADS)

    Lakshmi, V.

    2010-12-01

    MODIS Aqua and Terra satellites produce both land surface temperatures and sea surface temperatures using calibrated algorithms. In this study, the land surface temperatures were retrieved during clear-sky (non-cloudy) conditions at a 1 km2 resolution (overpass time at 10:30 am) whereas the sea surface temperatures are also retrieved during clear-sky conditions at approximately 4 km resolution (overpass time at 1:30 pm). The purpose of this research was to examine remotely sensed sea surface (SST), intertidal (IST), and land surface temperatures (LST), in conjunction with observed in situ mussel body temperatures, as well as associated weather and tidal data. In Strawberry Hill, Oregon, it was determined that intertidal surface temperatures are similar to but distinctly different from land surface temperatures although influenced by sea surface temperatures. The air temperature and differential heating throughout the day, as well as location in relation to the shore, can greatly influence the remotely sensed surface temperatures. Therefore, remotely sensed satellite data is a very useful tool in examining intertidal temperatures for regional climatic changes over long time periods and may eventually help researchers forecast expected climate changes and help determine associated biological implications.

  12. Saturn's F ring and shepherd satellites a natural outcome of satellite system formation

    NASA Astrophysics Data System (ADS)

    Hyodo, Ryuki; Ohtsuki, Keiji

    2015-09-01

    Saturn's F ring is a narrow ring of icy particles, located 3,400 km beyond the outer edge of the main ring system. Enigmatically, the F ring is accompanied on either side by two small satellites, Prometheus and Pandora, which are called shepherd satellites. The inner regular satellites of giant planets are thought to form by the accretion of particles from an ancient massive ring and subsequent outward migration. However, the origin of a system consisting of a narrow ring and shepherd satellites remains poorly understood. Here we present N-body numerical simulations to show that a collision of two of the small satellites that are thought to accumulate near the main ring's outer edge can produce a system similar to the F ring and its shepherd satellites. We find that if the two rubble-pile satellites have denser cores, such an impact results in only partial disruption of the satellites and the formation of a narrow ring of particles between two remnant satellites. Our simulations suggest that the seemingly unusual F ring system is a natural outcome at the final stage of the formation process of the ring-satellite system of giant planets.

  13. Energy deposition in the ionosphere derived from LEO satellite observations

    NASA Astrophysics Data System (ADS)

    Stolle, Claudia; Park, Jaeheung; Buchert, Stephan; Trulik, Vladimir; Bilitza, Dieter

    2014-05-01

    Ten years of successful operation of the multi-instrument CHAMP satellite mission at a unique orbit altitude of about 400 km revealed many interesting features of the coupling between the thermosphere and ionosphere. Different processes contribute to the deposition of solar and magnetospheric energy into the thermosphere. One important venue is heating through thermal electrons transferring energy by collisions with ions and neutrals. In the ionospheric F region thermal electrons are heated primarily through photoelectrons by local or non-local processes. At high latitudes soft precipitation and electromagnetic heating play a major role. The energy deposition can be quantified by a family of chemo-physical equations (Schunk and Nagy, 2009) that depend on plasma and neutral densities and temperatures. One important indicator for the energy transfer is the difference between electron and ion- and neutral- temperatures. Electron cooling leads to thermospheric heating and and we expect that this process leads to a local enhancement of mass density (air drag). Sizable electron cooling rates in the F region have been published from EISCAT radar observations in the ionospheric cusp. Based on CHAMP observation of electron density and temperature we estimate the energy deposit in the F-region through cooling of the thermal electron gas caused by elastic and inelastic processes. We find that a significant deposition is present during day at mid latitudes. At low latitudes the energy flux remains important until midnight. Observed heating rates depend on the satellite altitudes, but they are globally available from the CHAMP data. Missing observations in the CHAMP dataset, e.g., ion temperature, are derived from empirical models as IRI or MSIS. We investigate the global distribution of the electron cooling rate, we quantify the contributions of the different processes (equations) to the total energy transfer, e.g., depending on height, and we intend to compare our results with radar observations. Our focus is to apply Swarm observations also including ion temperature. We are interested in evaluating possible improvements when using the new Swarm observations instead empirical model results. These activities are preceded by a validation study of the Swarm Level-1b data derived from the Langmuir probe, e.g., electron density and temperature against estimations from IRI. From this project we expect to quantify the quality of the accuracy of the Langmuir Probe data within 20 percent uncertainty.

  14. 47 CFR 5.64 - Special provisions for satellite systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Special provisions for satellite systems. 5.64 Section 5.64 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL EXPERIMENTAL RADIO SERVICE Applications and Licenses § 5.64 Special provisions for satellite systems. (a) Construction of proposed experimental satellite facilities may...

  15. Pseudo-coherent demodulation for mobile satellite systems

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Simon, Marvin K.

    1993-01-01

    This paper proposes three so-called pseudo-coherent demodulation schemes for use in land mobile satellite channels. The schemes are derived based on maximum likelihood (ML) estimation and detection of an N-symbol observation of the received signal. Simulation results for all three demodulators are presented to allow comparison with the performance of differential PSK (DPSK) and ideal coherent demodulation for various system parameter sets of practical interest.

  16. Mutual Events of the Uranian Satellites Observed with the Faulkes Telescopes

    NASA Astrophysics Data System (ADS)

    Christou, Apostolos; Lewis, F.; Hidas, M. G.; Brown, T. M.; Roche, P.

    2008-09-01

    The 2007 Uranian Equinox allowed unique observations of the planet, its rings and satellites, possible only twice during the planet's 84 year orbit. Among these were mutual eclipses and occultations between the 5 classical satellites Ariel, Umbriel, Titania, Oberon and Miranda. These ``mutual'' events are extremely useful as reality checks of satellite ephemerides. In addition, they provide an opportunity to improve our knowledge of the satellite orbits and the system constants. We observed several mutual events in 2007 using the 2m Faulkes Telescopes North (FTN) and South (FTS) located in Haleakala, Maui and Siding Spring, Australia respectively, operated by the Las Cumbres Observatory Global Telescope (LCOGT) network. To mitigate against Uranus' glare, we utilized wide-band imaging in the near-IR, a small image scale and a posteriori subtraction of the planet's PSF. We obtained positive detections of six mutual events, three occultations and three eclipses, among these satellites. Three of these events involved Miranda, a difficult target due to its proximity to Uranus. Furthermore, we recorded at least two events that were predicted to occur with high confidence but did not, in fact, occur. During this presentation we will describe our observing strategy, operational setup and data reduction techniques and present examples of obtained lightcurves. Our observational results have been compared with predictions based on ephemerides by Laskar and Jacobson (1987; GUST86), by Lainey and Arlot (2006; LA06) and by Rush and Jacobson (2007; RJ07). Offsets with respect to the Voyager-era GUST86 are quite significant, of the order of minutes in the event midtimes. Smaller, yet significant trends in the data also appear with respect to LA06 and RJ07. We will discuss the nature of these trends and how they can be interpreted in terms of potential improvements in our knowledge of the Uranian system.

  17. Ambiguity resolution for satellite Doppler positioning systems

    NASA Technical Reports Server (NTRS)

    Argentiero, P.; Marini, J.

    1979-01-01

    The implementation of satellite-based Doppler positioning systems frequently requires the recovery of transmitter position from a single pass of Doppler data. The least-squares approach to the problem yields conjugate solutions on either side of the satellite subtrack. It is important to develop a procedure for choosing the proper solution which is correct in a high percentage of cases. A test for ambiguity resolution which is the most powerful in the sense that it maximizes the probability of a correct decision is derived. When systematic error sources are properly included in the least-squares reduction process to yield an optimal solution the test reduces to choosing the solution which provides the smaller valuation of the least-squares loss function. When systematic error sources are ignored in the least-squares reduction, the most powerful test is a quadratic form comparison with the weighting matrix of the quadratic form obtained by computing the pseudoinverse of a reduced-rank square matrix. A formula for computing the power of the most powerful test is provided. Numerical examples are included in which the power of the test is computed for situations that are relevant to the design of a satellite-aided search and rescue system.

  18. 47 CFR 5.64 - Special provisions for satellite systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...disclosing that fact shall be included in the debris mitigation disclosure. Such systems shall also indicate the anticipated evolution over time of the orbit of the proposed satellite or satellites. Where a space station operator requests the...

  19. 47 CFR 5.64 - Special provisions for satellite systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...disclosing that fact shall be included in the debris mitigation disclosure. Such systems shall also indicate the anticipated evolution over time of the orbit of the proposed satellite or satellites. Where a space station operator requests the...

  20. Communications satellite systems operations with the space station, volume 2

    NASA Technical Reports Server (NTRS)

    Price, K.; Dixon, J.; Weyandt, C.

    1987-01-01

    A financial model was developed which described quantitatively the economics of the space segment of communication satellite systems. The model describes the economics of the space system throughout the lifetime of the satellite. The expected state-of-the-art status of communications satellite systems and operations beginning service in 1995 were assessed and described. New or enhanced space-based activities and associated satellite system designs that have the potential to achieve future communications satellite operations in geostationary orbit with improved economic performance were postulated and defined. Three scenarios using combinations of space-based activities were analyzed: a spin stabilized satellite, a three axis satellite, and assembly at the Space Station and GEO servicing. Functional and technical requirements placed on the Space Station by the scenarios were detailed. Requirements on the satellite were also listed.

  1. Tropospheric effects of satellite power systems

    NASA Astrophysics Data System (ADS)

    Brubaker, K. L.; Lee, J.

    1980-05-01

    The effects of the launching of large rockets and the existence and operation of ground-based rectennas for satellite solar power systems on the troposphere are discussed. Consideration is given to the effects of the ground cloud produced by the heavy lift launch vehicles and personnel launch vehicles on the atmospheric content and deposition of gaseous air pollutants, the possible meteorological effects of the presence of a rectenna covering approximately 100 sq km on air temperature, local and mesoscale circulation patterns and cloud population, and to inadvertent weather modification caused by the proposed high level of space flight activity. Although environmentally significant ground-level concentrations of nitrogen dioxide, a possible enhancement of convective activity and small weather and climatic effects comparable to other land use changes are expected, no clearly unacceptable environmental effects of satellite solar power stations on the troposphere are identified.

  2. The investigation of tethered satellite system dynamics

    NASA Technical Reports Server (NTRS)

    Lorenzini, E.

    1985-01-01

    A progress report is presented that deals with three major topics related to Tethered Satellite System Dynamics. The SAO rotational dynamics computer code was updated. The program is now suitable to deal with inclined orbits. The output has been also modified in order to show the satellite Euler angles referred to the rotating orbital frame. The three-dimensional high resolution computer program SLACK3 was developed. The code simulates the three-dimensional dynamics of a tether going slack taking into account the effect produced by boom rotations. Preliminary simulations on the three-dimensional dynamics of a recoiling slack tether are shown in this report. A program to evaluate the electric potential around a severed tether is immersed in a plasma. The potential is computed on a three-dimensional grid axially symmetric with respect to the tether longitudinal axis. The electric potential variations due to the plasma are presently under investigation.

  3. The Role of Satellite Earth Observation Data in Monitoring and Verifying International Environmental Treaties

    NASA Technical Reports Server (NTRS)

    Johnston, Shaida

    2004-01-01

    The term verification implies compliance verification in the language of treaty negotiation and implementation, particularly in the fields of disarmament and arms control. The term monitoring on the other hand, in both environmental and arms control treaties, has a much broader interpretation which allows for use of supporting data sources that are not necessarily acceptable or adequate for direct verification. There are many ways that satellite Earth observation (EO) data can support international environmental agreements, from national forest inventories to use in geographic information system (GIs) tools. Though only a few references to satellite EO data and their use exist in the treaties themselves, an expanding list of applications can be considered in support of multilateral environmental agreements (MEAs). This paper explores the current uses of satellite Earth observation data which support monitoring activities of major environmental treaties and draws conclusions about future missions and their data use. The scope of the study includes all phases of environmental treaty fulfillment - development, monitoring, and enforcement - and includes a multinational perspective on the use of satellite Earth observation data for treaty support.

  4. Survey of the ionospheric disturbances related with large seismic events in multi-satellite ionospheric observations

    NASA Astrophysics Data System (ADS)

    Ryu, K.; Chae, J.; Lee, E.; Kil, H.

    2013-12-01

    We survey the ionospheric disturbances in the plasma and electro-magnetic wave measurements during the simultaneous observation period of DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions), CHAMP (CHAllenging Minisatellite Payload) and DMSP(Defense Meteorological Satellite Program) missions. The multi-satellite observation around three large earthquakes that occurred between 2004 and 2005 were investigated. The observational evidences of the earth-quake precursory phenomena and the recent progress of physical modeling of the ionospheric disturbances caused by the coupling of the stressed rock, Earth surface charges, atmosphere, and ionosphere system are reviewed. Then, we focus on identifying the precursory disturbances from the well-studied plasma disturbances in the ionosphere, which are known to originate from various physical mechanism other than the seismic activities. Electron density/temperature, ion density/temperature, and electro-magnetic field/wave data measured by various instruments equipped in the satellites were analyzed in finding specific examples of anomaly caused by large seismic activities. Finally, the possibility of forecasting or predicting large earthquakes using the plasma measurements of LEO (low earth orbit) satellites will be discussed.

  5. State Estimation from Sparse Observation Networks and Satellite Measurement

    NASA Astrophysics Data System (ADS)

    Bathmann, Kristen Ashley

    Filtering is the process of determining the statistically best estimate of a true signal based on partial, noisy observations. It is a two-step predictor-corrector scheme consisting of a forecast step, followed by an analysis step that updates the prediction as observations become available. In this thesis, two different filtering methods are applied under two different scenarios. In the first setting, two-dimensional irregularly spaced, sparsely observed turbulent signals are assimilated through a hierarchical Bayesian reduced stochastic filter. This approach is tested using a two-layer quasi-geostrophic model on a two-dimensional domain with a small radius of deformation to mimic ocean turbulence. The hierarchical strategy consists of two steps, combining a data-driven interpolation with the Mean Stochastic Model filter (MSM). Two interpolation schemes, a piecewise linear interpolation and ordinary kriging, are compared in this first step. Filtered estimates obtained from ordinary kriging are superior to those obtained from the linear interpolation when the observation networks are not too sparse, and the dynamical constraint of the MSM becomes important when the observation noise variance is large. In the second half of this thesis, the potential for using cloud-impacted satellite observations to improve the analysis estimate of the Local Ensemble Transform Kalman filter is assessed. Most data assimilation schemes with satellite data utilize only clear sky infrared radiances. However, cloudy radiances contain significant information about the atmospheric state and could have a positive impact on weather prediction. This study is based on synthetic Atmospheric Infrared Sounder (AIRS) measurements, incorporating the temperature and humidity profiles of the multicloud model, a toy model that simulates tropical convection. The key parameters that induce filter bias in the presence of a cloud are identified. In particular, the cloud cover percent, and, more importantly, the cloud top pressure are the two most crucial parameters to estimate correctly. Furthermore, this study also provides error bounds on the analyses based on using cloud-impacted AIRS data. The findings here suggest that with reasonable estimates of cloud cover percent and cloud top pressure, cloudy AIRS data can be potentially as effective as clear sky data, and could enhance numerical weather prediction.

  6. Satellites - New global observing techniques for ice and snow

    NASA Technical Reports Server (NTRS)

    Gloersen, P.; Salomonson, V. V.

    1975-01-01

    The possibility that the variation in areal extent of the snow cover may be related by empirical means to the average monthly run-off in a given watershed was demonstrated by comparing run-off records from the Indus River Basin in south-east Asia with a series of snow-cover maps obtained from Nimbus-3 and 4 imagery. Similar studies using the higher spatial resolution available with ERTS-1 imagery were carried out for the Wind River Mountains watersheds in Wyoming, where it was found that the empirical relationship varied with mean elevation of the watershed. In addition, digital image enhancement techniques are shown to be useful for identifying glacier features thought to be related to extent of snow cover, moraine characteristics, debris coverage, and the like. Finally, longer wavelength observations using sensors on board the Nimbus-5 satellite are shown to be useful for indicating crystal size distributions and onset of melting on glacier snow cover.

  7. Terrestrial Myriametric Radio Burst Observed by IMAGE and Geotail Satellites

    NASA Technical Reports Server (NTRS)

    Fung, Shing F.; Hashimoto, KoZo; Kojima, Hirotsugu; Boardson, Scott A.; Garcia, Leonard N.; Matsumoto, Hiroshi; Green, James L.; Reinisch, Bodo W.

    2013-01-01

    We report the simultaneous detection of a terrestrial myriametric radio burst (TMRB) by IMAGE and Geotail on 19 August 2001. The TMRB was confined in time (0830-1006 UT) and frequency (12-50kHz). Comparisons with all known nonthermal myriametric radiation components reveal that the TMRB might be a distinct radiation with a source that is unrelated to the previously known radiation. Considerations of beaming from spin-modulation analysis and observing satellite and source locations suggest that the TMRB may have a fan beamlike radiation pattern emitted by a discrete, dayside source located along the poleward edge of magnetospheric cusp field lines. TMRB responsiveness to IMF Bz and By orientations suggests that a possible source of the TMRB could be due to dayside magnetic reconnection instigated by northward interplanetary field condition.

  8. Establishing the Antarctic Dome C community reference standard site towards consistent measurements from Earth observation satellites

    USGS Publications Warehouse

    Cao, C.; Uprety, S.; Xiong, J.; Wu, A.; Jing, P.; Smith, D.; Chander, G.; Fox, N.; Ungar, S.

    2010-01-01

    Establishing satellite measurement consistency by using common desert sites has become increasingly more important not only for climate change detection but also for quantitative retrievals of geophysical variables in satellite applications. Using the Antarctic Dome C site (75°06?S, 123°21?E, elevation 3.2 km) for satellite radiometric calibration and validation (Cal/Val) is of great interest owing to its unique location and characteristics. The site surface is covered with uniformly distributed permanent snow, and the atmospheric effect is small and relatively constant. In this study, the long-term stability and spectral characteristics of this site are evaluated using well-calibrated satellite instruments such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and Sea-viewing Wide Field-of-view Sensor (SeaWiFS). Preliminary results show that despite a few limitations, the site in general is stable in the long term, the bidirectional reflectance distribution function (BRDF) model works well, and the site is most suitable for the Cal/Val of reflective solar bands in the 0.4–1.0 µm range. It was found that for the past decade, the reflectivity change of the site is within 1.35% at 0.64 µm, and interannual variability is within 2%. The site is able to resolve calibration biases between instruments at a level of ~1%. The usefulness of the site is demonstrated by comparing observations from seven satellite instruments involving four space agencies, including OrbView-2–SeaWiFS, Terra–Aqua MODIS, Earth Observing 1 (EO-1) – Hyperion, Meteorological Operational satellite programme (MetOp) – Advanced Very High Resolution Radiometer (AVHRR), Envisat Medium Resolution Imaging Spectrometer (MERIS) – dvanced Along-Track Scanning Radiometer (AATSR), and Landsat 7 Enhanced Thematic Mapper Plus (ETM+). Dome C is a promising candidate site for climate quality calibration of satellite radiometers towards more consistent satellite measurements, as part of the framework for climate change detection and data quality assurance for the Global Earth Observation System of Systems (GEOSS).

  9. Earth Observatory Satellite (EOS) system definition study

    NASA Technical Reports Server (NTRS)

    1974-01-01

    An executive summary of a study on the Earth Observatory Satellite (EOS) was presented. It was concluded that the overall costs of space systems could be reduced significantly by the development of a modular shuttle compatible standard spacecraft, and the use of that spacecraft with the Shuttle Transportation System. It was also demonstrated that the development of the standard spacecraft is feasible, desirable, and cost effective if applied to a series of missions. The ability to initially retrieve, refurbish, and reuse the spacecraft and its payload, and ultimately to perform in-orbit servicing, would result in significant cost savings. A number of specific conclusions and recommendations were also suggested.

  10. Operational aspects of satellite data collection systems

    NASA Technical Reports Server (NTRS)

    Morakis, J. C.

    1979-01-01

    Operational aspects of satellite data collection systems (DCS) are discussed with consideration given to a cooperative program between the United States and France. The Tiros-N DCS is described which is a random access system providing operational capability for position location and/or data collection of 4000 to 16,000 moving and/or fixed platforms. The platform transmissions and processing of the data is designed to conform with the user needs. The position location is obtained through ground processing of Doppler measurements made by the data collection instrument on board the spacecraft.

  11. Satellite communications systems and technology. Executive Summary

    NASA Technical Reports Server (NTRS)

    Edelson, Burton I.; Pelton, Joseph N.; Bostian, Charles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Helm, Neil R.; Jennings, Raymond D.; Kwan, Robert; Mahle, Christoph E.

    1993-01-01

    NASA and the National Science Foundation (NSF) commissioned a panel of US experts to study the international status of satellite communications systems and technology. The study covers emerging systems concepts, applications, services, and the attendant technologies. The panel members travelled to Europe, Japan, and Russia to gather information first-hand. They visited 17 sites in Europe, 20 sites in Japan, and four in Russia. These included major manufacturers, government organizations, service providers, and associated R&D facilities. The panel's report was reviewed by the sites visited, by the panel, and by representatives of US industry. The report details the information collected and compares it to US activities.

  12. FIDEX: An expert system for satellite diagnostics

    NASA Technical Reports Server (NTRS)

    Durkin, John; Tallo, Donald; Petrik, Edward J.

    1991-01-01

    A Fault Isolation and Diagnostic Expert system (FIDEX) was developed for communication satellite diagnostics. It was designed specifically for the 30/20 GHz satellite transponder. The expert system was designed with a generic structure and features that make it applicable to other types of space systems. FIDEX is a frame based system that enjoys many of the inherent frame base features, such as hierarchy that describes the transponder's components, with other hierarchies that provide structural and fault information about the transponder. This architecture provides a flexible diagnostic structure and enhances maintenance of the system. FIDEX also includes an inexact reasoning technique and a primitive learning ability. Inexact reasoning was an important feature for this system due to the sparse number of sensors available to provide information on the transponder's performance. FIDEX can determine the most likely faulted component under the constraint of limited information. FIDEX learns about the most likely faults in the transponder by keeping a record of past established faults. FIDEX also has the ability to detect anomalies in the sensors that provide information on the transponders performance.

  13. Astrometric positions for 18 irregular satellites of giant planets from 23 years of observations

    NASA Astrophysics Data System (ADS)

    Gomes-Júnior, A. R.; Assafin, M.; Vieira-Martins, R.; Arlot, J.-E.; Camargo, J. I. B.; Braga-Ribas, F.; da Silva Neto, D. N.; Andrei, A. H.; Dias-Oliveira, A.; Morgado, B. E.; Benedetti-Rossi, G.; Duchemin, Y.; Desmars, J.; Lainey, V.; Thuillot, W.

    2015-08-01

    Context. The irregular satellites of the giant planets are believed to have been captured during the evolution of the solar system. Knowing their physical parameters, such as size, density, and albedo is important for constraining where they came from and how they were captured. The best way to obtain these parameters are observations in situ by spacecrafts or from stellar occultations by the objects. Both techniques demand that the orbits are well known. Aims: We aimed to obtain good astrometric positions of irregular satellites to improve their orbits and ephemeris. Methods: We identified and reduced observations of several irregular satellites from three databases containing more than 8000 images obtained between 1992 and 2014 at three sites (Observatório do Pico dos Dias, Observatoire de Haute-Provence, and European Southern Observatory - La Silla). We used the software Platform for Reduction of Astronomical Images Automatically (PRAIA) to make the astrometric reduction of the CCD frames. The UCAC4 catalog represented the International Celestial Reference System in the reductions. Identification of the satellites in the frames was done through their ephemerides as determined from the SPICE/NAIF kernels. Some procedures were followed to overcome missing or incomplete information (coordinates, date), mostly for the older images. Results: We managed to obtain more than 6000 positions for 18 irregular satellites: 12 of Jupiter, 4 of Saturn, 1 of Uranus (Sycorax), and 1 of Neptune (Nereid). For some satellites the number of obtained positions is more than 50% of what was used in earlier orbital numerical integrations. Conclusions: Comparison of our positions with recent JPL ephemeris suggests there are systematic errors in the orbits for some of the irregular satellites. The most evident case was an error in the inclination of Carme. Position tables are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/580/A76 and IAU NSDC database at http://www.imcce.fr/nsdcPartially based on observations made at Laboratório Nacional de Astrofísica (LNA), Itajubá-MG, Brazil.Partially based on observations through the ESO runs 079.A-9202(A), 075.C-0154, 077.C-0283 and 079.C-0345.Partially based on observations made at Observatoire de Haute Provence (OHP), 04870 Saint-Michel l'observatoire, France.

  14. Improvements and Extensions for Joint Polar Satellite System Algorithms

    NASA Astrophysics Data System (ADS)

    Grant, K. D.; Feeley, J. H.; Miller, S. W.; Jamilkowski, M. L.

    2014-12-01

    The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). JPSS replaced the afternoon orbit component and ground processing system of the old POES system managed by the NOAA. JPSS satellites will carry sensors designed to collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The ground processing system for the JPSS is the Common Ground System (CGS), and provides command, control, and communications (C3), data processing and product delivery. CGS's data processing capability processes the data from the JPSS satellites to provide environmental data products (including Sensor Data Records (SDRs) and Environmental Data Records (EDRs)) to the NOAA Satellite Operations Facility. The first satellite in the JPSS constellation, known as the Suomi National Polar-orbiting Partnership (S-NPP) satellite, was launched on 28 October 2011. CGS is currently processing and delivering SDRs and EDRs for S-NPP and will continue through the lifetime of the JPSS program. The EDRs for S-NPP are currently undergoing an extensive Calibration and Validation (Cal/Val) campaign. Changes identified by the Cal/Val campaign are coming available for implementation into the operational system in support of both S-NPP and JPSS-1 (scheduled for launch in 2017). Some of these changes will be available in time to update the S-NPP algorithm baseline, while others will become operational just prior to JPSS-1 launch. In addition, new capabilities, such as higher spectral and spatial resolution, will be exercised on JPSS-1. This paper will describe changes to current algorithms and products as a result of the Cal/Val campaign and related initiatives for improved capabilities. Improvements include Cross Track Infrared Sounder high spectral processing, extended spectral and spatial ranges for Ozone Mapping and Profiler Suite ozone Total Column and Nadir Profiles, and updates to Vegetation Index, Snow Cover, Active Fires, Suspended Matter, and Ocean Color. Updates will include Sea Surface Temperature, Cloud Mask, Cloud Properties, and other improvements.

  15. Observations of H? surges and ultraviolet jets above satellite sunspots

    NASA Astrophysics Data System (ADS)

    Chen, H. D.; Jiang, Y. C.; Ma, S. L.

    2008-02-01

    Aims:To know more about the physical origin of surges and jets, we investigated seven successive surge events, which occurred above the satellite sunspots of active region NOAA 10720 on 2005 January 15. Methods: Using data from the Transition Region and Coronal Explorer (TRACE), Big Bear Solar Observatory (BBSO) and Solar and Heliospheric Observatory (SOHO), we present a detailed study of the surges and their relations with the associated small arch filament, UV jets, flares and photospheric longitudinal magnetic fields. Results: The seven H? surges we studied repeatedly occurred where the photospheric longitudinal fluxes of opposite magnetic polarities emerged, converged and were canceled by each other. Correspondingly, a small satellite spot emerged, decayed and disappeared during a period of about 2 hours in the white-light observations. In morphology, all surges displayed almost linear ejective structures. Their dynamic properties, such as the transverse velocity, projected maximum length and lifetime, varied in wide ranges. They are 30-200 km s-1, 38 000-220 000 km and from several to tens of minutes, respectively. Correspondingly, the intensities of their correlated microflares were different too. The surges of major velocities or maximum lengths seemed to be accompanied by processes of more energy release. Prior to these surge events, a small H? arch filament connecting the opposite flux elements was found at the base region. Instead of erupting completely, it gradually disappeared during the surges. Its role in the surge activities is very like a bipolar flux, which contained the cool plasma and reconnected with the ambient magnetic fields. In 1600 Å, three surge events exhibited the composite structures of bright jets and nearby small flaring loops, which provides direct evidence of magnetic reconnection origin of the surges. A careful comparison revealed that the ends of the arch filament, the UV jets and the small flaring loops just corresponded to the interacting longitudinal fluxes in the photosphere. Conclusions: These observational results support the magnetic reconnection model of surges and jets.

  16. Earth observations satellite data policy: Process and outcome

    SciTech Connect

    Shaffer, L.R.

    1994-12-31

    The National Aeronautics and Space Administration (NASA) develops, launches, and operates satellites to observe and monitor the Earth and its environment. This study categorizes each program based on the relationship between NASA and external organizations. A program can be an autonomous mission undertaken for NASA`s own constituency, or it can involve a client agency or a partner. These relationships affect how data policy decisions are made and implemented, and how the valuable output of NASA`s Earth observations satellites is managed. The process in NASA for determining which programs will be approved is very informal. Ideas and concepts surface and reach the consciousness of NASA management; if sufficient support is achieved, a proposal can move to the feasibility study phase and from there become an approved and funded mission. The handling of data can be an important consideration in generating political support for program approval. Autonomous programs tend to have decisions made at lower levels and documented informally or not at all. Data policy is part of routine implementation of programs and does not generally rise to the visibility of the agency head or congressional staff or the Executive Office of the President. Responsibility for data management for autonomous missions is retained at NASA centers. Client programs involve higher level decision makers, and are the subject of political interest because they cross agency boundaries. The data policy process includes presidential statements on data access. As part of the client relationship, NASA often provides resources to the client for data handling and analysis, and shares these responsibilities. Data policy for partner programs is the result of bargaining between the partners, either foreign government agencies or private companies.

  17. Investigation of Interpolation for Solar Irradiation in Non-Observed Point Based on Satellite Images

    NASA Astrophysics Data System (ADS)

    Shinoda, Yukio; Fujisawa, Sei; Seki, Tomomichi

    Penetrating the Photovoltaic Power Generation System (PV) on an enormous scale over a next decade has some crucial problems which affect on, for example, power grid stabilization and operation including existing power stations for electric power utilities. It would be therefore important for future operation to estimate power output generated by PV in advance. We focus on interpolation using observed solar irradiation (SI) and brightness of pixel on a satellite visible image for estimating SI even in non-observed point. Our results by single regression analysis between observed SI and brightness on a satellite image as cloudiness show that a shift of highest determination coefficient on each hour would represent solar movement and this higher determination coefficient would indicate a position which SI and cloud would cross. Finally assessment of error in this interpolation shows enough accuracy at least in daytime period, which is important for electricity utilities.

  18. Committee on Earth Observation Satellites (CEOS) Systems Engineering Office (SEO). Ocean Surface Topography (OST) Workshop, Ruedesheim an Rhein, Germany. [CEOS SEO Status Report

    NASA Technical Reports Server (NTRS)

    Killough, Brian D., Jr.

    2008-01-01

    The CEOS Systems Engineering Office will present a 2007 status report of the CEOS constellation process, present a new systems engineering framework, and analysis results from the GEO Societal Benefit Area (SBA) assessment and the OST constellation requirements assessment.

  19. Satellites: New global observing techniques for ice and snow. [using erts-1 and nimbus 5 satellite

    NASA Technical Reports Server (NTRS)

    Gloersen, P.; Salomonson, V. V.

    1974-01-01

    The relation of aereal extent of snow cover to the average monthly runoff in a given watershed was investigated by comparing runoff records with a series of snowcover maps. Studies using the high spatial resolution available with ERTS-1 imagery were carried out for the Wind River Mountains watersheds in Wyoming, where it was found that the empirical relationship varied with mean elevation of the watershed. In addition, digital image enhancement techniques are shown to be useful for identifying glacier features related to extent of snowcover, moraine characteristics, and debris average. Longer wavelength observations using sensors on board the Nimbus 5 Satellite are shown to be useful for indicating crystal size distributions and onset of melting on glacier snow cover.

  20. ORIGIN OF THE DIFFERENT ARCHITECTURES OF THE JOVIAN AND SATURNIAN SATELLITE SYSTEMS

    SciTech Connect

    Sasaki, T.; Ida, S.; Stewart, G. R. E-mail: ida@geo.titech.ac.j

    2010-05-10

    The Jovian regular satellite system mainly consists of four Galilean satellites that have similar masses and are trapped in mutual mean-motion resonances except for the outer satellite, Callisto. On the other hand, the Saturnian regular satellite system has only one big icy body, Titan, and a population of much smaller icy moons. We have investigated the origin of these major differences between the Jovian and Saturnian satellite systems by semi-analytically simulating the growth and orbital migration of proto-satellites in an accreting proto-satellite disk. We set up two different disk evolution/structure models that correspond to Jovian and Saturnian systems, by building upon previously developed models of an actively supplied proto-satellite disk, the formation of gas giants, and observations of young stars. Our simulations extend previous models by including the (1) different termination timescales of gas infall onto the proto-satellite disk and (2) different evolution of a cavity in the disk, between the Jovian and Saturnian systems. We have performed Monte Carlo simulations and have shown that in the case of the Jovian systems, four to five similar-mass satellites are likely to remain trapped in mean-motion resonances. This orbital configuration is formed by type I migration, temporal stopping of the migration near the disk inner edge, and quick truncation of gas infall caused by Jupiter opening a gap in the solar nebula. The Saturnian systems tend to end up with one dominant body in the outer regions caused by the slower decay of gas infall associated with global depletion of the solar nebula. The total mass and compositional zoning of the predicted Jovian and Saturnian satellite systems are consistent with the observed satellite systems.

  1. Engineering calculations for communications satellite systems planning

    NASA Technical Reports Server (NTRS)

    Reilly, C. H.; Levis, C. A.; Buyukdura, O. M.; Mount-Campbell, C. A.

    1986-01-01

    Observed solution times were analyzed for the extended gradient and cyclic coordinate search procedures. The times used in the analysis come from computer runs made during a previously-reported experiment conducted to assess the quality of the solutions to a BSS synthesis problem found by the two search methods. The results of a second experiment with a Fixed Satellite Service (FSS) test problem are also presented. Computational results are summarized for mixed integer programming approaches for solving FSS synthesis problems. A promising heuristic algorithm is described. A synthesis model is discussed for orbital arc allotment optimization. Research plans for the near future are also presented.

  2. Advanced Microelectronics Technologies for Future Small Satellite Systems

    NASA Technical Reports Server (NTRS)

    Alkalai, Leon

    1999-01-01

    Future small satellite systems for both Earth observation as well as deep-space exploration are greatly enabled by the technological advances in deep sub-micron microelectronics technologies. Whereas these technological advances are being fueled by the commercial (non-space) industries, more recently there has been an exciting new synergism evolving between the two otherwise disjointed markets. In other words, both the commercial and space industries are enabled by advances in low-power, highly integrated, miniaturized (low-volume), lightweight, and reliable real-time embedded systems. Recent announcements by commercial semiconductor manufacturers to introduce Silicon On Insulator (SOI) technology into their commercial product lines is driven by the need for high-performance low-power integrated devices. Moreover, SOI has been the technology of choice for many space semiconductor manufacturers where radiation requirements are critical. This technology has inherent radiation latch-up immunity built into the process, which makes it very attractive to space applications. In this paper, we describe the advanced microelectronics and avionics technologies under development by NASA's Deep Space Systems Technology Program (also known as X2000). These technologies are of significant benefit to both the commercial satellite as well as the deep-space and Earth orbiting science missions. Such a synergistic technology roadmap may truly enable quick turn-around, low-cost, and highly capable small satellite systems for both Earth observation as well as deep-space missions.

  3. Cassini VIMS observations of the Galilean satellites including the VIMS calibration procedure

    USGS Publications Warehouse

    McCord, T.B.; Coradini, A.; Hibbitts, C.A.; Capaccioni, F.; Hansen, G.B.; Filacchione, G.; Clark, R.N.; Cerroni, P.; Brown, R.H.; Baines, K.H.; Bellucci, G.; Bibring, J.-P.; Buratti, B.J.; Bussoletti, E.; Combes, M.; Cruikshank, D.P.; Drossart, P.; Formisano, V.; Jaumann, R.; Langevin, Y.; Matson, D.L.; Nelson, R.M.; Nicholson, P.D.; Sicardy, B.; Sotin, C.

    2004-01-01

    The Visual and Infrared Mapping Spectrometer (VIMS) observed the Galilean satellites during the Cassini spacecraft's 2000/2001 flyby of Jupiter, providing compositional and thermal information about their surfaces. The Cassini spacecraft approached the jovian system no closer than about 126 Jupiter radii, about 9 million kilometers, at a phase angle of < 90 ??, resulting in only sub-pixel observations by VIMS of the Galilean satellites. Nevertheless, most of the spectral features discovered by the Near Infrared Mapping Spectrometer (NIMS) aboard the Galileo spacecraft during more than four years of observations have been identified in the VIMS data analyzed so far, including a possible 13C absorption. In addition, VIMS made observations in the visible part of the spectrum and at several new phase angles for all the Galilean satellites and the calculated phase functions are presented. In the process of analyzing these data, the VIMS radiometric and spectral calibrations were better determined in preparation for entry into the Saturn system. Treatment of these data is presented as an example of the VIMS data reduction, calibration and analysis process and a detailed explanation is given of the calibration process applied to the Jupiter data. ?? 2004 Elsevier Inc. All rights reserved.

  4. System implementation for Earth Radiation Budget Satellite System

    NASA Technical Reports Server (NTRS)

    Cooper, J. E.; Woerner, C. V.

    1978-01-01

    A description is presented of the instrument system which is needed for the Earth Radiation Budget Satellite System (ERBSS). The system is to be composed of instruments on two of NOAA's near-polar sun-synchronous Tiros-N/NOAA A through G series of operational satellites and on a NASA midinclination satellite of the Applications Explorer Mission (AEM) type referred to as ERBS-A/AEM. The Tiros-N/NOAA satellites will be in nominal 833 km altitude circular orbits with orbital inclinations of 98 deg. The AEM satellite will be in a circular orbit with an inclination of approximately 56 deg and a nominal altitude of 600 km. Each satellite will carry wide field-of-view (WFOV) and medium field-of-view (MFOV) sensors, a sensor for measuring the solar constant, and a narrow field-of-view (NFOV) cross-track scanner. The conceptual design of the W/MFOV instrument is discussed along with the conceptual design of the scanner.

  5. Determining the orbits of EGNOS satellites based on optical or microwave observations

    NASA Astrophysics Data System (ADS)

    Beutler, G.; Hugentobler, U.; Ploner, M.; Meindl, M.; Schildknecht, T.; Urschl, C.

    The satellites of geostationary navigation overlay systems such as EGNOS (European Geostationary Navigation Overlay System) are equipped with single-frequency microwave transponders. The tracking data contain a GPS-like signal corresponding to the GPS C/A-code (Clear Access code) in the GPS L1-band of the electromagnetic spectrum. This signal is tracked by (some of the) commercially available GPS receivers and may be used for orbit determination and for the estimation of EGNOS clock corrections. GPS and EGNOS observations, acquired by eight combined GPS/EGNOS receivers in a time interval of five days in spring 2004, were used (a) to precisely position the GPS/EGNOS tracking sites (using the conventional GPS observables) and (b) to determine the EGNOS orbits and clock corrections using the EGNOS C/A-code observable. The resulting orbit determination scheme proved to be robust and accurate in particular in view of the fact that only L1 C/A-code was analyzed. The quality of the procedure, which might be easily transformed into a routine EGNOS orbit determination scheme, is discussed in our article. The EGNOS satellites can also be observed with optical telescopes (situated in the appropriate geographical longitude sector). The observed astrometric places may be used to determine EGNOS orbits, as well. In spring 2004 an observation campaign using the 1-m telescope in Zimmerwald (near Bern in Switzerland) was organized to acquire observations for two EGNOS satellites. Based on these optical observations orbits were determined for one of the EGNOS spacecrafts. The quality of this complementary and independent orbit determination procedure is discussed, as well. Accurate EGNOS orbits may thus be derived with two independent methods. For the current study, however, no observations of the two types could be made available and orbits resulting from the two methods could not be compared directly. This step, as well as a combined processing of the two observation types, is planned for the future.

  6. Monitoring tropical cyclone evolution with NOAA satellite microwave observations

    NASA Technical Reports Server (NTRS)

    Velden, C.; Smith, W. L.

    1983-01-01

    NOAA satellite microwave soundings, which penetrate high clouds, delineate the development and dissipation of the upper tropospheric warm core associated with a tropical cyclone. The storm's 'core" may be detected from microwave imagery. Vertical cross sections reveal the intensification of the upper tropospheric warm core as the storm develops, and the downward propagation of the warm core as the storm dissipates. Excellent correlation is found between the horizontal Laplacian of an upper tropospheric temperature field and the intensity of the storm, as categorized by its surface central pressure and maximum sustained wind speed at the eye wall. The microwave monitoring of tropical cyclones is achieved in real time at the University of Wisconsin's Space Science and Engineering Center through high-speed teleconnections to direct readout receiving systems at Wallops Island, Virginia and Redwood City, California.

  7. Arctic Sea Ice Thickness from Satellite Observations, Aircraft Field Campaign Measurements, and Numerical Model Simulations

    NASA Astrophysics Data System (ADS)

    Wang, X.; Kwok, R.; Zhang, J.; Liu, Y.; Key, J.

    2013-12-01

    Sea ice is an important indicator and effective modulator of regional and global climate change because it significantly affects the complex exchanges of momentum, heat, and mass between the sea and atmosphere. At present, there are datasets for Arctic sea ice thickness from satellite observations, aircraft field campaign measurements, numerical model simulations, and some in-situ measurements. Among satellite derived data sets, one satellite ice thickness product has been generated using NASA's Ice, Cloud and Land Elevation Satellite (ICESat) Geoscience Laser Altimeter System (GLAS) observations (Kwok et al., 2009), another has been produced from long-term optical (visible, near-IR, and thermal IR) imager data from NOAA Polar Orbiting Satellites (Wang et al., 2010). The approaches are completely different: the ICESat product estimates ice thickness from surface elevation; the optical imager approach estimates ice thickness by solving the surface energy budget equation. NASA's IceBridge program fills the gap between the loss of ICESat in 2010 and the launch of ICESat-2 in 2016. IceBridge employs an aircraft for altimeter and other measurements of the ice sheets and sea ice. The IceBridge Snow Radar, Digital Mapping System (DMS), Continuous Airborne Mapping By Optical Translator (CAMBOT), and Airborne Topographic Mapper (ATM) instruments can be used to estimate ice thickness with a methodology similar to that used for ICESat. Ice thickness has also been modeled with the numerical model called Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) (Zhang and Rothrock, 2003). Arctic sea ice thickness estimates from these different data sources will be examined and inter-compared to evaluate their consistency and validity with in-situ measurements. Arctic sea ice thickness variations over time and space will be also investigated.

  8. Classification of Clouds and Deep Convection from GEOS-5 Using Satellite Observations

    NASA Technical Reports Server (NTRS)

    Putman, William; Suarez, Max

    2010-01-01

    With the increased resolution of global atmospheric models and the push toward global cloud resolving models, the resemblance of model output to satellite observations has become strikingly similar. As we progress with our adaptation of the Goddard Earth Observing System Model, Version 5 (GEOS-5) as a high resolution cloud system resolving model, evaluation of cloud properties and deep convection require in-depth analysis beyond a visual comparison. Outgoing long-wave radiation (OLR) provides a sufficient comparison with infrared (IR) satellite imagery to isolate areas of deep convection. We have adopted a binning technique to generate a series of histograms for OLR which classify the presence and fraction of clear sky versus deep convection in the tropics that can be compared with a similar analyses of IR imagery from composite Geostationary Operational Environmental Satellite (GOES) observations. We will present initial results that have been used to evaluate the amount of deep convective parameterization required within the model as we move toward cloud system resolving resolutions of 10- to 1-km globally.

  9. Orbital design strategy for domestic communication satellite systems.

    NASA Technical Reports Server (NTRS)

    Ramji, S.; Sawitz, P.

    1973-01-01

    Review of some of the considerations pertinent to efficient orbit utilization in the design of domestic communications satellite systems. A strategy is developed to efficiently locate a heterogeneous system of satellites within the available arc and provide room for future growth. A practical design is illustrated, using a computer simulation model, for the placement of 25 satellites within 73% of the available arc employing frequency and polarization coordination techniques. A number of widely variable factors that influence satellite spacing are examined. These factors include such critical system elements as telephony and television interference noise limits, frequency plan coordination, polarization plan coordination, ground antenna diameter, signal protection ratio, and satellite station keeping.

  10. Satellite microwave observations of soil moisture variations. [by the microwave radiometer on the Nimbus 5 satellite

    NASA Technical Reports Server (NTRS)

    Schmugge, T. J.; Rango, A.; Neff, R.

    1975-01-01

    The electrically scanning microwave radiometer (ESMR) on the Nimbus 5 satellite was used to observe microwave emissions from vegetated and soil surfaces over an Illinois-Indiana study area, the Mississippi Valley, and the Great Salt Lake Desert in Utah. Analysis of microwave brightness temperatures (T sub B) and antecedent rainfall over these areas provided a way to monitor variations of near-surface soil moisture. Because vegetation absorbs microwave emission from the soil at the 1.55 cm wavelength of ESMR, relative soil moisture measurements can only be obtained over bare or sparsely vegetated soil. In general T sub B increased during rainfree periods as evaporation of water and drying of the surface soil occurs, and drops in T sub B are experienced after significant rainfall events wet the soil. Microwave observations from space are limited to coarse resolutions (10-25 km), but it may be possible in regions with sparse vegetation cover to estimate soil moisture conditions on a watershed or agricultural district basis, particularly since daily observations can be obtained.

  11. Prospects for satellite and space debris observations with Pi of the Sky

    NASA Astrophysics Data System (ADS)

    ?wiek, A.; Batsch, T.; Majcher, A.; Mankiewicz, L.; Wrochna, G.; Zadro?ny, A.; ?arnecki, A. F.

    2015-09-01

    Pi of the Sky is a system of wide field-of-view robotic telescopes designed for observations of short timescale astrophysical phenomena, especially for prompt optical GRB emission. The apparatus designed for autonomous operation follows the predefined observing strategy and adopts to the actual running conditions, monitoring a large part of the sky with time resolution of the order of 1 - 10 seconds and range 12m-13m. Observation strategy and system design was successfully tested with a prototype detector in Chile and starting 2013 the final Pi of the Sky detector system in operation at the INTA El Arenosillo Test Centre in Spain. For the analysis of the data from a wide field-of-view system a set of dedicated algorithms have been developed, which allowed us to reduce photometry uncertainty for bright stars to the level of 0.015m- 0.02m. Design of the Pi of the Sky telescopes allows also for measurements of near-Earth objects as comets, asteroids, satellites and space debris. Precise determination of the orbit parameters of the geostationary satellites is possible when using a parallax measured with simultaneous observations from Spain and Chile. Dedicated tests have been performed recently to verify system capabilities for observation of objects on lower orbits, moving at higher speeds. First results are discussed in this contribution.

  12. Development of a Reduction Algorithm of GEO Satellite Optical Observation Data for Optical Wide Field Patrol (OWL)

    NASA Astrophysics Data System (ADS)

    Park, Sun-youp; Choi, Jin; Jo, Jung Hyun; Son, Ju Young; Park, Yung-Sik; Yim, Hong-Suh; Moon, Hong-Kyu; Bae, Young-Ho; Choi, Young-Jun; Park, Jang-Hyun

    2015-09-01

    An algorithm to automatically extract coordinate and time information from optical observation data of geostationary orbit satellites (GEO satellites) or geosynchronous orbit satellites (GOS satellites) is developed. The optical wide-field patrol system is capable of automatic observation using a pre-arranged schedule. Therefore, if this type of automatic analysis algorithm is available, daily unmanned monitoring of GEO satellites can be possible. For data acquisition for development, the COMS1 satellite was observed with 1-s exposure time and 1-m interval. The images were grouped and processed in terms of ¡°action¡±, and each action was composed of six or nine successive images. First, a reference image with the best quality in one action was selected. Next, the rest of the images in the action were geometrically transformed to fit in the horizontal coordinate system (expressed in azimuthal angle and elevation) of the reference image. Then, these images were median-combined to retain only the possible non-moving GEO candidates. By reverting the coordinate transformation of the positions of these GEO satellite candidates, the final coordinates could be calculated.

  13. Payload system tradeoffs for mobile communications satellites

    NASA Technical Reports Server (NTRS)

    Moody, H. J.

    1990-01-01

    System level trade-offs carried out during Mobile Satellite (M-SAT) design activities are described. These trade-offs relate to the use of low level beam forming, flexible power and spectrum distribution, and selection of the number of beams to cover the service area. It is shown that antenna performance can be improved by sharing horns between beams using a low level beam forming network (BFN). Additionally, greatly increased power utilization is possible using a hybrid matrix concept to share power between beams.

  14. Satellite Power System (SPS) student participation

    NASA Technical Reports Server (NTRS)

    Ladwig, A.; David, L.

    1978-01-01

    A assessment of methods which are appropriate to initiate student participation in the discussion of a satellite power system (SPS) is presented. Methods which are incorporated into the campus environment and the on-going learning experience are reported. The discussion of individual methods for student participation includes a description of the technique, followed by comments on its enhancing and limiting factors, references to situations where the method has been demonstrated, and a brief consideration of cost factors. The two categories of recommendations presented are: an outline of fourteen recommendations addressing specific activities related to student participation in the discussion of SPS, and three recommendations pertaining to student participation activities in general.

  15. The precision of today's satellite laser ranging systems

    NASA Technical Reports Server (NTRS)

    Dunn, Peter J.; Torrence, Mark H.; Hussen, Van S.; Pearlman, Michael R.

    1993-01-01

    Recent improvements in the accuracy of modern satellite laser ranging (SLR) systems are strengthened by the new capability of many instruments to track an increasing number of geodetic satellite targets without significant scheduling conflict. This will allow the refinement of some geophysical parameters, such as solid Earth tidal effects and GM, and the improved temporal resolution of others, such as Earth orientation and station position. Better time resolution for the locations of fixed observatories will allow us to monitor more subtle motions at the stations, and transportable systems will be able to provide indicators of long term trends with shorter occupations. If we are to take advantage of these improvements, care must be taken to preserve the essential accuracy of an increasing volume of range observations at each stage of the data reduction process.

  16. Space Weathering on Icy Satellites in the Outer Solar System

    NASA Astrophysics Data System (ADS)

    Clark, Roger N.; Perlman, Zachary; Pearson, Neil; Cruikshank, Dale P.

    2014-11-01

    Space weathering produces well-known optical effects in silicate minerals in the inner Solar System, for example, on the Moon. Space weathering from solar wind and UV is expected to be weaker in the outer Solar System simply because intensities are lower. However, cosmic rays from inner to outer solar system would be similar to first order. Similarly with micrometeoroid bombardment. That, combined with the much higher volatility of icy surfaces means there is the potential for space weathering on icy outer Solar System surfaces to show optical effects. The Cassini spacecraft orbiting Saturn is providing evidence for space weathering on icy bodies. The Cassini VIMS instrument has spatially mapped satellite surfaces and the rings from .35-5 microns and the UVIS instrument from 0.1 to 0.2 microns. These data have sampled a complex mixing space between H2O ice and non-ice components and they show some common spectral properties. Similarly, spectra of the icy Galilean satellites and satellites in the Uranian system have some commonality in spectral properties with those in the Saturn system. The UV absorber is spectrally similar on many surfaces. VIMS has identified CO2, H2 and trace organics in varying abundances on Saturn's satellites. We postulate that through the spatial relationships of some of these compounds that they are created and destroyed through space weathering effects. For example, the trapped H2 and CO2 observed by VIMS in regions with high concentrations of dark material may in part be space weathering products from the destruction of H2O and organic molecules. The dark material, particularly on Iapetus which has the highest concentration in the Saturn system, is well matched by space-weathered silicates in the .4-2.6 micron range, and the spectral shapes closely match those of the most mature lunar soils, another indicator of space weathered material.

  17. THE THREE-DIMENSIONAL STRUCTURE OF THE M31 SATELLITE SYSTEM; STRONG EVIDENCE FOR AN INHOMOGENEOUS DISTRIBUTION OF SATELLITES

    SciTech Connect

    Conn, A. R.; Parker, Q. A.; Zucker, D. B.; Lewis, G. F.; Ibata, R. A.; Martin, N. F.; McConnachie, A. W.; Valls-Gabaud, D.; Tanvir, N.; Irwin, M. J.; Ferguson, A. M. N.; Chapman, S. C.

    2013-04-01

    We undertake an investigation into the spatial structure of the M31 satellite system utilizing the distance distributions presented in a previous publication. These distances make use of the unique combination of depth and spatial coverage of the Pan-Andromeda Archaeological Survey to provide a large, homogeneous sample consisting of 27 of M31's satellites, as well as M31 itself. We find that the satellite distribution, when viewed as a whole, is no more planar than one would expect from a random distribution of equal size. A disk consisting of 15 of the satellites is however found to be highly significant, and strikingly thin, with an rms thickness of just 12.34{sup +0.75}{sub -0.43} kpc. This disk is oriented approximately edge-on with respect to the Milky Way and almost perpendicular to the Milky Way disk. It is also roughly orthogonal to the disk-like structure regularly reported for the Milky Way satellite system and in close alignment with M31's Giant Stellar Stream. A similar analysis of the asymmetry of the M31 satellite distribution finds that it is also significantly larger than one would expect from a random distribution. In particular, it is remarkable that 20 of the 27 satellites most likely lie on the Milky Way side of the galaxy, with the asymmetry being most pronounced within the satellite subset forming the aforementioned disk. This lopsidedness is all the more intriguing in light of the apparent orthogonality observed between the satellite disk structures of the Milky Way and M31.

  18. Trend detection in satellite observations of formaldehyde tropospheric columns

    NASA Astrophysics Data System (ADS)

    De Smedt, I.; Stavrakou, T.; Müller, J.-F.; van der A, R. J.; Van Roozendael, M.

    2010-09-01

    Being an intermediate product in the oxidation of a large number of non-methane volatile organic compounds (NMVOCs), formaldehyde (H2CO) is a useful indicator of biogenic, pyrogenic and anthropogenic hydrocarbon emissions. We present the first trend study performed on H2CO satellite columns, retrieved from the GOME and SCIAMACHY instruments between 1997 and 2009. A linear model with a seasonal component is used to fit the time series of monthly averaged columns. The error and statistical significance of the inferred trends are estimated. The study focuses on Asia but results are also provided for large cities worldwide. Statistically significant positive trends of formaldehyde columns are observed over northeastern China (4% yr-1) and India (1.6% yr-1), related to strong increases in anthropogenic NMVOC emissions, whereas negative trends of about -3% yr-1 are observed over Tokyo as well as over cities of the northeast U.S. urban corridor as a result of effective pollution regulation measures.

  19. Satellite Observations of Antarctic Sea Ice Thickness and Volume

    NASA Technical Reports Server (NTRS)

    Kurtz, Nathan; Markus, Thorsten

    2012-01-01

    We utilize satellite laser altimetry data from ICESat combined with passive microwave measurements to analyze basin-wide changes in Antarctic sea ice thickness and volume over a 5 year period from 2003-2008. Sea ice thickness exhibits a small negative trend while area increases in the summer and fall balanced losses in thickness leading to small overall volume changes. Using a five year time-series, we show that only small ice thickness changes of less than -0.03 m/yr and volume changes of -266 cu km/yr and 160 cu km/yr occurred for the spring and summer periods, respectively. The calculated thickness and volume trends are small compared to the observational time period and interannual variability which masks the determination of long-term trend or cyclical variability in the sea ice cover. These results are in stark contrast to the much greater observed losses in Arctic sea ice volume and illustrate the different hemispheric changes of the polar sea ice covers in recent years.

  20. Satellite observations of large power plants and megacities from GOSAT

    NASA Astrophysics Data System (ADS)

    Oda, Tom; Maksyutov, Shamil; Boesch, Hartmut; Butz, Andre; Ganshin, Alexander; Guerlet, Sandrine; Parker, Robert; O'Dell, Chris; Oshchepkov, Sergey; Yoshida, Yukio; Zhuravlev, Ruslan; Yokota, Tatsuya

    2013-04-01

    Fossil fuel CO2 emissions are a major source of CO2 to the global carbon cycle over decadal time scales and international efforts to curb those missions are required for mitigating climate change. Although emissions from nations are estimated and reported to help monitor their compliance of emission reductions, we still lack an objective method to monitor emissions directly. Future carbon-observing space missions are thus expected to provide an independent tool for directly measuring emissions. We proposed and have implemented satellite observations specifically over intense large point sources (LPS), including large fossil-fueled power plants and megacities, worldwide (N > 300) using the Japanese Greenhouse Gases Observing SATelllite (GOSAT). Our target LPS sites have been occasionally included in the observation schedule of GOSAT and the measurements are made using the target observation mode. This proposal was officially accepted by the GOSAT project office and we have attempted to use these data to detect signatures of man-made greenhouse gas emissions. We have submitted our locations of interest on a monthly basis two month prior to observation. We calculated the X_CO2 concentration enhancement due to the LPS emissions. We analyzed GOSAT X_CO2 retrievals from four research groups (five products total): the National Institute for Environmental Studies (NIES) (both the NIES standard Level 2 and NIES-PPDF products), the NASA Atmospheric CO2 from Space (ACOS) team (ACOS Level 2 product), the Netherlands Institute for Space Research (SRON)/Karlsruhe Institute of Technology, Germany (RemoTeC), and the University of Leicester, UK (Full-Physics CO2 retrieval dataset). Although we obtained fewer retrieved soundings relative to what we requested (probably due to geophysical difficulties in the retrievals), we did obtain statistically significant enhancements at some LPS sites where weather condition were ideal for viewing. We also implemented simulations of enhanced X_CO2 using a global Eulerian-Lagrangian coupled atmospheric transport model (GELCA) and a high-resolution fossil fuel emissions dataset (Odiac). Odiac includes emissions information on the power plants requested in our target observations. Our model simulations tend to underestimate the enhancements, but showed good correlation with observed enhancements.

  1. Monitoring of global geodynamic processes using satellite observations

    NASA Astrophysics Data System (ADS)

    Tatevian, S. K.; Attia, G. F.; Abou-Aly, N.; Ghoneim, R.; Hegazy, M.

    2014-06-01

    To study mechanisms of destructive geodynamic phenomena including determination of places of possible severe earthquakes, volcano eruptions and some other natural hazards, it is important to have means to evolve areas where maximum changes of the displacement velocities and the terrestrial crust vertical movements are possible. The previous experience has shown that the satellite geodesy techniques including global navigation systems and satellite laser ranging are the most effective for research activities in this field. Permanent control of secular movement of GPS-stations of the international geodynamic network, located in Russia, has allowed improving the reference coordinate frame for North Eurasia since Russian network stations provide representative covering of the largest stable areas (the Siberian and the East European) of the Eurasian plate. Along its southern border, there is a zone consisting of a great number of microplates surrounding the South-Eurasian stable plate. Interaction of these small plates and blocks influences distribution of seismic stresses in internal parts of the continent that is confirmed by the highest seismic activity of the triangle bordered by thrusts of the Himalayas and faults of the Pamirs, the Tien-Shan, the Baikal and the North-Eastern China. One of the active tectonic zones of Egypt located in Aswan, is characterized by regional basement rock uplift and regional faulting. In 1997, the African Regional Geodynamic Network was developed around the northern part of Lake Nasser, consists of 11 points, on both sides of the Lake. Its main goal is to study the geodynamical behavior around the northern part of the lake. The collected data were processed using the Bernese software version 5.0. From the velocity results, including also the African plate motion, it can be noticed that all stations of this network are moved to the northeast direction and it is typically the direction of the African plate motion.

  2. Spectroradiometric considerations for advanced land observing systems

    NASA Technical Reports Server (NTRS)

    Slater, P. N.

    1986-01-01

    Research aimed at improving the inflight absolute radiometric calibration of advanced land observing systems was initiated. Emphasis was on the satellite sensor calibration program at White Sands. Topics addressed include: absolute radiometric calibration of advanced remote sensing; atmospheric effects on reflected radiation; inflight radiometric calibration; field radiometric methods for reflectance and atmospheric measurement; and calibration of field relectance radiometers.

  3. Assimilating multi-sensor satellite observations for initializing hydrologic and agricultural forecasts

    NASA Astrophysics Data System (ADS)

    Andreadis, Konstantinos; Das, Narendra; Granger, Stephanie; Han, Eunjin; Ines, Amor; Stampoulis, Dimitrios

    2015-04-01

    The application of data assimilation techniques in hydrologic studies has been gaining traction in the last 10-15 years. Most of these studies have focused on a single water cycle component, while few studies have examined methods of assimilating multiple observations from different sensors and of different hydrologic variables. The latter is challenging since any potential disparities in the observations could lead to suboptimal estimates after assimilation. The optimal estimates of hydrologic states, such as soil moisture, can be used as initial conditions for hydrologic forecasting systems. A multi-sensor and multivariate data assimilation forecast system has been developed at JPL (RHEAS, Regional Hydrologic Extremes Assessment System) with an initial focus on forecasting drought characteristics. The core of RHEAS is the VIC hydrology model, which has been widely used for many water resources applications. Apart from hydrologic forecasts, RHEAS can produce agricultural forecasts by coupling VIC with the DSSAT crop growth model. The modeling system is supported by a spatial database component, which provides access to multiple in-situ and satellite observations and allows data to be delivered to users through web-GIS or mobile application interfaces. The satellite observations, which include soil moisture, water storage, evapotranspiration, and snow cover, are assimilated into the VIC model to update the initial state of seasonal hydrologic and crop growth forecasts. We demonstrate the value of ingesting satellite observations by performing a series of hindcast experiments over both the United States (California and Upper Colorado basins) and Kenya (Nzoia basin). In-situ measurements along with a simulation with the best available datasets are used as the benchmark to evaluate the hindcasts against. The impact of each observation type or sensor is quantified, allowing for evaluating their relative contribution to improving the forecast skill. Particular case studies that are discussed in more detail include the ongoing California as well as the 2011 East Africa droughts.

  4. Climate studies from satellite observations - Special problems in the verification of earth radiation balance, cloud climatology, and related climate experiments

    NASA Technical Reports Server (NTRS)

    Vonder Haar, T. H.

    1982-01-01

    A body of techniques that have been developed and planned for use during the Earth Radiation Budget Experiment (ERBE), the International Satellite Cloud Climatology Project (ISCCP), and related climate experiments of the 1980's are reviewed. Validation and verification methods must apply for systems of satellites. They include: (1) use of a normalization or intercalibration satellite, (2) special intensive observation areas located over ground-truth sites, and (3) monitoring of sun and earth by several satellites and/or several instruments at the same time. Since each climate application area has a hierarchy of user communities, validation techniques vary from very detailed methods to those that simply assure high relative accuracy in detecting space and time variations for climate studies. It is shown that climate experiments generally require more emphasis on long-term stability and internal consistency of satellite data sets than high absolute accuracy.

  5. Detailed Analysis of Indian Summer Monsoon Rainfall Processes with Modern/High-Quality Satellite Observations

    NASA Technical Reports Server (NTRS)

    Smith, Eric A.; Kuo, Kwo-Sen; Mehta, Amita V.; Yang, Song

    2007-01-01

    We examine, in detail, Indian Summer Monsoon rainfall processes using modernhigh quality satellite precipitation measurements. The focus here is on measurements derived from three NASA cloud and precipitation satellite missionslinstruments (TRMM/PR&TMI, AQUNAMSRE, and CLOUDSATICPR), and a fourth TRMM Project-generated multi-satellite precipitation measurement dataset (viz., TRMM standard algorithm 3b42) -- all from a period beginning in 1998 up to the present. It is emphasized that the 3b42 algorithm blends passive microwave (PMW) radiometer-based precipitation estimates from LEO satellites with infi-ared (IR) precipitation estimates from a world network of CEO satellites (representing -15% of the complete space-time coverage) All of these observations are first cross-calibrated to precipitation estimates taken from standard TRMM combined PR-TMI algorithm 2b31, and second adjusted at the large scale based on monthly-averaged rain-gage measurements. The blended approach takes advantage of direct estimates of precipitation from the PMW radiometerequipped LEO satellites -- but which suffer fi-om sampling limitations -- in combination with less accurate IR estimates from the optical-infrared imaging cameras on GEO satellites -- but which provide continuous diurnal sampling. The advantages of the current technologies are evident in the continuity and coverage properties inherent to the resultant precipitation datasets that have been an outgrowth of these stable measuring and retrieval technologies. There is a wealth of information contained in the current satellite measurements of precipitation regarding the salient precipitation properties of the Indian Summer Monsoon. Using different datasets obtained from the measuring systems noted above, we have analyzed the observations cast in the form of: (1) spatially distributed means and variances over the hierarchy of relevant time scales (hourly I diurnally, daily, monthly, seasonally I intra-seasonally, and inter-annually), (2) time series at these different time scales taken as area-averages over the hierarchy of relevant space scales (Indian sub-Division, Indian sub-continent, and Circumambient Indian Ocean), (3) principal autocorrelation and cross-correlation structures over various monsoon space-time domains, (4) diurnally modulated amplitude-phase properties of rain rates over different monsoon space-time domains, (5) foremost rain rate probability distributions intrinsic to monsoon precipitation, and (6) behavior of extreme events including occurrences of flood and drought episodes throughout the course of inter-annual monsoon processes.

  6. New Constraints on Additional Satellites of the Pluto System

    E-print Network

    A. J. Steffl; M. J. Mutchler; H. A. Weaver; S. A. Stern; D. D. Durda; D. Terrell; W. J. Merline; L. A. Young; E. F. Young; M. W. Buie; J. R. Spencer

    2006-05-23

    Observations of Pluto and its solar-tidal stability zone were made using the Advanced Camera for Surveys' (ACS) Wide Field Channel (WFC) on the Hubble Space Telescope on UT 2005 May 15 and UT 2005 May 18. Two small satellites of Pluto, provisionally designated S/2005 P 1 and S/2005 P 2, were discovered, as discussed by Weaver et al. (2006) and Stern et al. (2006a). Confirming observations of the newly discovered moons were obtained using the ACS in the High Resolution Channel (HRC) mode on 2006 Feb 15 (Mutchler et al. 2006). Both sets of observations provide strong constraints on the existence of any additional satellites in the Pluto system. Based on the May 2005 observations using the ACS/WFC, we place a 90%-confidence lower limit of m_V = 26.8 (m_V = 27.4 for a 50%-confidence lower limit) on the magnitude of undiscovered satellites greater than 5" (1.1x10^5 km) from Pluto. Using the 2005 Feb 15 ACS/HRC observations we place 90%-confidence lower limits on the apparent magnitude of any additional satellites of m_V = 26.4 between 3"-5" (6.9x10^4-1.1x10^5 km) from Pluto, m_V = 25.7 between 1"-3" (2.3x10^4-6.9x10^4 km) from Pluto, and m_V = 24. between 0.3"-1" (6.9x10^3-2.3x10^4 km) from Pluto. The 90%-confidence magnitude limits translate into upper limits on the diameters of undiscovered satellites of 29 km outside of 5" from Pluto, 36 km between 3"-5" from Pluto, 49 km between 1"-3" from Pluto, and 115 km between 0.3"-1" for a comet-like albedo of p_V = 0.04. If potential satellites are assumed to have a Charon-like albedo of p_V = 0.38, the diameter limits are 9 km, 12 km, 16 km, and 37 km, respectively.

  7. National Satellite Forest Monitoring systems for REDD+

    NASA Astrophysics Data System (ADS)

    Jonckheere, I. G.

    2012-12-01

    Reducing Emissions from Deforestation and Forest Degradation (REDD) is an effort to create a financial value for the carbon stored in forests, offering incentives for developing countries to reduce emissions from forested lands and invest in low-carbon paths to sustainable development. "REDD+" goes beyond deforestation and forest degradation, and includes the role of conservation, sustainable management of forests and enhancement of forest carbon stocks. In the framework of getting countries ready for REDD+, the UN-REDD Programme assists developing countries to prepare and implement national REDD+ strategies. For the monitoring, reporting and verification, FAO supports the countries to develop national satellite forest monitoring systems that allow for credible measurement, reporting and verification (MRV) of REDD+ activities. These are among the most critical elements for the successful implementation of any REDD+ mechanism. The UN-REDD Programme through a joint effort of FAO and Brazil's National Space Agency, INPE, is supporting countries to develop cost- effective, robust and compatible national monitoring and MRV systems, providing tools, methodologies, training and knowledge sharing that help countries to strengthen their technical and institutional capacity for effective MRV systems. To develop strong nationally-owned forest monitoring systems, technical and institutional capacity building is key. The UN-REDD Programme, through FAO, has taken on intensive training together with INPE, and has provided technical help and assistance for in-country training and implementation for national satellite forest monitoring. The goal of the support to UN-REDD pilot countries in this capacity building effort is the training of technical forest people and IT persons from interested REDD+ countries, and to set- up the national satellite forest monitoring systems. The Brazilian forest monitoring system, TerraAmazon, which is used as a basis for this initiative, allows countries to adapt it to country needs and the training on the TerraAmazon system is a tool to enhance existing capacity on carbon monitoring systems. The support with the National Forest Monitoring System will allow these countries to follow all actions related to the implementation of its national REDD+ policies and measures. The monitoring system will work as a platform to obtain information on their REDD+ results and actions, related directly or indirectly to national REDD+ strategies and may also include actions unrelated to carbon assessment, such as forest law enforcement. With the technical assistance of FAO, INPE and other stakeholders, the countries will set up an autonomous operational forest monitoring system. An initial version and the methodologies of the system for DRC and PNG has been launched in Durban, South Africa during COP 17 and in 2012 Paraguay, Viet Nam and Zambia will be launched in Doha, Qatar at COP 18. The access to high-quality satellite data for these countries is crucial for the set-up.

  8. Jupiter System Observer

    NASA Technical Reports Server (NTRS)

    Senske, Dave; Prockter, Louise

    2008-01-01

    This slide presentation reviews the scientific philosophy that is guiding the planning behind the Jupiter System Observer (JSO). The JSO would be a long-term platform for studying Jupiter and the complete Jovian system. The goal is to advance the understanding of the fundamental processes of planetary systems, their formation and evolution.

  9. Joint Polar Satellite System (JPSS) System Architecture: Suomi-NPP to the Future

    NASA Astrophysics Data System (ADS)

    Furgerson, J.; Layns, A.; Feeley, J. H.; Griffin, A.; Trumbower, G.

    2014-12-01

    The National Oceanic and Atmospheric Administration (NOAA) is acquiring the next-generation weather and environmental satellite system, named the Joint Polar Satellite System (JPSS). NOAA has overall responsibility for the system including funding and requirements while the National Aeronautics and Space Administration (NASA) serves as the acquisition and development agent. The Suomi National Polar-orbiting Partnership (S-NPP) satellite was launched on 28 October, 2011, and is a pathfinder for JPSS and provides continuity for the NASA Earth Observation System and the NOAA Polar-orbiting Operational Environmental Satellite (POES) system. S-NPP and the follow-on JPSS satellites will operate in the 1330 LTAN orbit. JPSS-1 is scheduled to launch in early 2017. NASA is developing the Common Ground System which will process JPSS data and has the flexibility to process data from other satellites. This poster will provide a top level status update of the program, as well as an overview of the JPSS system architecture. The space segment carries a suite of sensors that collect meteorological, oceanographic, and climatological observations of the earth and atmosphere. The system design allows centralized mission management and delivers high quality environmental products to military, civil and scientific users through a Command, Control, and Communication Segment (C3S). The data processing for S-NPP/JPSS is accomplished through an Interface Data Processing Segment (IDPS)/Field Terminal Segment (FTS) that processes S-NPP/JPSS satellite data to provide environmental data products to U.S. and international partners as well as remote terminal users throughout the world.

  10. Satellite power system (SPS) public outreach experiment

    SciTech Connect

    McNeal, S.R.

    1980-12-01

    To improve the results of the Satellite Power System (SPS) Concept Development and Evaluation Program, an outreach experiment was conducted. Three public interest groups participated: the L-5 Society (L-5), Citizen's Energy Project (CEP), and the Forum for the Advancement of Students in Science and Technology (FASST). Each group disseminated summary information about SPS to approximately 3000 constituents with a request for feedback on the SPS concept. The objectives of the outreach were to (1) determine the areas of major concern relative to the SPS concept, and (2) gain experience with an outreach process for use in future public involvement. Due to the combined efforts of all three groups, 9200 individuals/organizations received information about the SPS concept. Over 1500 receipients of this information provided feedback. The response to the outreach effort was positive for all three groups, suggesting that the effort extended by the SPS Project Division to encourage an information exchange with the public was well received. The general response to the SPS differed with each group. The L-5 position is very much in favor of SPS; CEP is very much opposed and FASST is relatively neutral. The responses are analyzed, and from the responses some questions and answers about the satellite power system are presented in the appendix. (WHK)

  11. Satellite-aided land mobile communications system implementation considerations

    NASA Technical Reports Server (NTRS)

    Leroy, B. E.

    1982-01-01

    It was proposed that a satellite-based land mobile radio system could effectively extend the terrestrial cellular mobile system into rural and remote areas. The market, technical and economic feasibility for such a system is studied. Some of the aspects of implementing an operational mobile-satellite system are discussed. In particular, two key factors in implementation are examined: (1) bandwidth requirements; and (2) frequency sharing. Bandwidth requirements are derived based on the satellite antenna requirements, modulation characteristics and numbers of subscribers. Design trade-offs for the satellite system and potential implementation scenarios are identified. Frequency sharing is examined from a power flux density and modulation viewpoint.

  12. 218 IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, VOL. 22, NO. 2, FEBRUARY 2004 Cache Satellite Distribution Systems: Modeling,

    E-print Network

    Levy, Hanoch

    218 IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, VOL. 22, NO. 2, FEBRUARY 2004 Cache Satellite observed by Web clients. Cache satellite distribution systems (CSDSs) have emerged as a technology. The central station selects a collection of Web documents, which are "pushed" via a satellite broadcast

  13. Observational capabilities of solar satellite "Coronas-Photon"

    NASA Astrophysics Data System (ADS)

    Kotov, Yu.

    Coronas-Photon mission is the third satellite of the Russian Coronas program on solar activity observation The main goal of the Coronas-Photon is the study of solar hard electromagnetic radiation in the wide energy range from UV up to high energy gamma-radiation sim 2000MeV Scientific payload for solar radiation observation consists of three type of instruments 1 monitors Natalya-2M Konus-RF RT-2 Penguin-M BRM Phoka Sphin-X Sokol for spectral and timing measurements of full solar disk radiation with timing in flare burst mode up to one msec Instruments Natalya-2M Konus-RF RT-2 will cover the wide energy range of hard X-rays and soft Gamma rays 15keV to 2000MeV and will together constitute the largest area detectors ever used for solar observations Detectors of gamma-ray monitors are based on structured inorganic scintillators with energy resolution sim 5 for nuclear gamma-line band to 35 for GeV-band PSD analysis is used for gamma neutron separation for solar neutron registration T 30MeV Penguin-M has capability to measure linear polarization of hard X-rays using azimuth are measured by Compton scattering asymmetry in case of polarization of an incident flux For X-ray and EUV monitors the scintillation phoswich detectors gas proportional counter CZT assembly and Filter-covered Si-diodes are used 2 Telescope-spectrometer TESIS for imaging solar spectroscopy in X-rays with angular resolution up to 1 in three spectral lines and RT-2 CZT assembly of CZT

  14. Engineering calculations for communications satellite systems planning

    NASA Technical Reports Server (NTRS)

    Reilly, Charles H.; Walton, Eric K.; Kohnhorst, Paul

    1987-01-01

    A procedure is described that was used to calculate minimum required satellite separations based on total link carrier to interference requirements. Also summarized are recent results with a switching algorithm for satellite synthesis problems. Analytic solution value bounds for two of the satellite synthesis models studied are described. Preliminary results from an empirical study of alternate mixed integer programming models for satellite synthesis are presented. Research plans for the near future are discussed.

  15. Observations in the thermal IR and visible of a retired satellite in the graveyard orbit, and comparisons to active satellites in GEO

    NASA Astrophysics Data System (ADS)

    Skinner, Mark A.; Russell, Ray W.; Kelecy, Tom; Gregory, Steve; Rudy, Richard J.; Kim, Daryl L.; Crawford, Kirk

    2014-12-01

    There exists a population of defunct satellites in the geo-stationary arc that potentially pose a hazard to current and future operational satellites. These drifting, non-station-kept objects have a variety of ages and sizes, and many are trapped in libration orbits around the Earth's two gravitational potential wells (the non-spherical nature of the Earth gives rise to two geo-potential wells or "stable points" that affect objects in geostationary and geosynchronous orbits), whereas others were boosted to higher altitudes into so-called "graveyard" orbits. We have observed several of the approximately 49 objects in libration orbits about the Western stable point (R. Choc, T. Flohrer, and B. Bastida, "Classification of Geosynchronous Objects," Issue 13, ESA/ESOC, February 2011), as well as objects in graveyard orbits. We have carried out an observational campaign utilizing The Aerospace Corporation's 3-13 ?m Broadband Array Spectrograph System (BASS), as well as with several optical sensors to collect data on a representative sample of these objects at a variety of solar phase angles. Here we report on recent BASS observations of a retired satellite in the "graveyard" orbit, and compare them with data we had collected over six years ago, while the satellite was still active. Data are also presented on similar satellites that are still active. We describe our methods, the data collected, our results, and our future plans.

  16. Satellite-derived normalized difference convection index for typhoon observations

    NASA Astrophysics Data System (ADS)

    Liu, Chung-Chih; Shyu, Tian-Yow; Lin, Tang-Huang; Liu, Chian-Yi

    2015-01-01

    This study used the spectral features of the geostationary satellite infrared window channel and the water vapor channel data to calculate a new parameter, normalized difference convection index (NDCI), to help determine the overshooting areas in typhoon cloud systems and the centers and intensity of typhoons. The results showed that the two-dimensional NDCI analysis helped to identify typhoon convective cloud systems and the positions of overshooting areas. In addition, because the NDCI values near a typhoon eye were rather significant, if a typhoon eye was formed, the NDCI cross-section analysis could help to confirm its position. When the center of a typhoon was covered by the high anvils and cirrus layers, it could still be qualitatively found through two-dimensional analysis. As for determining the intensity of typhoons, this study also tried to perform correlation analyses with NDCI and maximum sustained wind speed. The result showed that in the ranges within circles of 200 to 250 km radii with a typhoon eye as the center, the correlation between the area with the NDCI values <0 and the maximum sustained wind speed is high with a coefficient 0.7. Thus, the NDCI value could be a referential index to determine the intensity of a typhoon.

  17. Retrofitting a fine-pointing system to satellite optics

    NASA Technical Reports Server (NTRS)

    Woods, Robert O.

    1995-01-01

    This paper describes a system added to an existing satellite-borne telescope design for the purpose of compensating the boresight errors that had been observed in earlier flights of similar instruments. Those errors had been found to be caused by thermal distortion of the spaceframe. This retrofit design was subjected to severe volume restrictions because it was fitted into an already tightly-packaged instrument envelope. It was found practical to improve the basic design by converting a redundant structure into a statically-determinate one. It was also possible to use portions of the mechanical actuation system to facilitate the position encoding needed for computer interfacing.

  18. Mars Operational Environmental Satellite (MOES): A post-Mars Observer discovery mission

    NASA Technical Reports Server (NTRS)

    Limaye, Sanjay S.

    1993-01-01

    Mars Operational Environmental Satellite (MOES) is a Discovery concept mission that is designed to observe the global short-term weather phenomena on Mars in a systematic fashion. Even after the Mariner, Viking, and, soon, Mars Observer missions, crucial aspects of the martian atmosphere will remain unobserved systematically. Achieving a better understanding of the cycles of dust, water vapor, and ices on Mars requires detailed information about atmospheric transports of those quantities associated with the weather systems, particularly those arising in mid latitudes during fall and winter. It also requires a quantitive understanding of the processes responsible for the onset and evolution of dust storms on all scales. Whereas on Earth the system of geosynchronous and polar orbiting satellites provides continuous coverage of the weather systems, on Mars the time history of important events such as regional and global dust storms remains unobserved. To understand the transport of tracers in the martian atmosphere and particularly to identify their sources and sinks, it is necessary to have systematic global, synoptic observations that have yet to be attained. Clearly these requirements are not easy to achieve from a single spacecraft in orbit, but if we focus on specific regions of the planet, e.g., polar vs. low and mid latitudes, then it is possible to attain a nearly ideal coverage at a reasonable spatial and temporal resolution with a system of just two satellites. Mars Observer is about to yield good coverage of the polar latitudes, so we focus initially on the region not covered well in terms of diurnal coverage, and in terms of desired observations will provide the initial data for the numerical models of the martian weather and climate that can be verified only with better temporal and spatial data.

  19. Observing System Simulation Experiments

    NASA Technical Reports Server (NTRS)

    Prive, Nikki

    2015-01-01

    This presentation gives an overview of Observing System Simulation Experiments (OSSEs). The components of an OSSE are described, along with discussion of the process for validating, calibrating, and performing experiments. a.

  20. Making Data Visible: Satellite Observations of Arctic Change (SOAC)

    NASA Astrophysics Data System (ADS)

    Beitler, J.; Tanner, S.; Barrett, A. P.; Savoie, M. H.; Wilcox, H.; Hoyer, T.; Beam, K.

    2014-12-01

    A new Web site, Satellite Observations of Arctic Change (SOAC, http://nsidc.org/soac), was developed to open up NASA Earth science data that show changes taking place in the Arctic over time to a broader range of users. The site was designed to be used by decision makers, teachers, non-specialist scientists, and the motivated public without the need for technical tools or expertise in manipulating data. The data are displayed on interactive maps, allowing users to explore how and where conditions in the Arctic have changed from the 1970s to the present. Users may animate a time series, zoom in or out, and view a bar graph of anomalies over time. Supporting pages provide brief scientific discussion and background to help users understand the data and the significance of the changes. Links to the source data and documentation are also included. Initial data products for SOAC include anomalies associated with near-surface air temperature; water vapor; sea ice concentration; snow cover; and several others. The potential for use and for inclusion of more data will be discussed.

  1. First Satellite Observations of Lower Tropospheric Ammonia and Methanol

    NASA Technical Reports Server (NTRS)

    Beer, Reinhard; Shephard, Mark W.; Kulawik, Susan S.; Clough, Shepard A.; Eldering, Annmarie; Bowman, Kevin W.; Sander, Stanley P.; Fisher, Brendan M.; Payne, Vivienne H.; Luo, Mingzhao; Osterman, Gregory B.; Worden, John R.

    2008-01-01

    The Tropospheric Emission Spectrometer (TES) on the EOS Aura satellite makes global measurements of infrared radiances which are used to derive profiles of species such as O3, CO, H2O, HDO and CH4 as routine standard products. In addition, TES has a variety of special modes that provide denser spatial mapping over a limited geographical area. A continuous-coverage mode (called ''transect'', about 460 km long) has now been used to detect additional molecules indicative of regional air pollution. On 10 July 2007 at about 05:37 UTC (13:24 LMST) TES conducted such a transect observation over the Beijing area in northeast China. Examination of the residual spectral radiances following the retrieval of the TES standard products revealed surprisingly strong features attributable to enhanced concentrations of ammonia (NH3) and methanol (CH3OH), well above the normal background levels. This is the first time that these molecules have been detected in space-based nadir viewing measurements that penetrate into the lower atmosphere.

  2. Multipath study for a low altitude satellite utilizing a data relay satellite system

    NASA Technical Reports Server (NTRS)

    Eggert, D.

    1970-01-01

    Technical considerations associated with a low altitude satellite operating in conjuction with a data relay satellite system are reported. Emphasis was placed on the quantitative characterization of multipath phenomenon and determination of power received via both the direct and earth reflection paths. Attempts were made to develop a means for estimating the magnitude and nature of the reflected power.

  3. SAW based systems for mobile communications satellites

    NASA Technical Reports Server (NTRS)

    Peach, R. C.; Miller, N.; Lee, M.

    1993-01-01

    Modern mobile communications satellites, such as INMARSAT 3, EMS, and ARTEMIS, use advanced onboard processing to make efficient use of the available L-band spectrum. In all of these cases, high performance surface acoustic wave (SAW) devices are used. SAW filters can provide high selectivity (100-200 kHz transition widths), combined with flat amplitude and linear phase characteristics; their simple construction and radiation hardness also makes them especially suitable for space applications. An overview of the architectures used in the above systems, describing the technologies employed, and the use of bandwidth switchable SAW filtering (BSSF) is given. The tradeoffs to be considered when specifying a SAW based system are analyzed, using both theoretical and experimental data. Empirical rules for estimating SAW filter performance are given. Achievable performance is illustrated using data from the INMARSAT 3 engineering model (EM) processors.

  4. The 'INMARSAT' international maritime satellite communication system

    NASA Astrophysics Data System (ADS)

    Atserov, Iu. S.

    1982-12-01

    The history, design, operating characteristics, achievements, and prospects of INMARSAT are discussed. More than 1300 ships are presently equipped to operate within the system, and this number is expected to rise to about 5000 by 1986. The principle of operation involves single coordinating earth stations allocating telephone channels in their zones between other earth stations. The messages reach a common signalling channel with which all ship stations keep in touch. The ship stations are connected to the international telex network. The INMARSAT system enables ships in the automated mode of operation to establish telephone and telegraph comunication with any subscriber on the shore of any country. The quality of the communication is practically independent of the distance between ship and shore at any time of year and under any meteorological conditions. Estimates indicate that the use of satellite communication with ships reduces losses from accidents by 10 percent per year.

  5. NATO III satellite communications system control

    NASA Astrophysics Data System (ADS)

    Sanli, N.; Lo, S. C.; Kota, S. L.; Aronson, M. H.

    1984-04-01

    The System Control concepts to improve channel utilization and the recent progress of the design, development and integration of the Control Subsystem for the NATO III network are reported. The network operates with a large number of single destination TDM/QPSK/FDMA carriers to provide voice, low speed telegraph and medium speed data circuits. A power control algorithm to keep the link quality at the desired nominal level as well as improve satellite capacity and a traffic control algorithm allowing reconfiguration of the network to accommodate fluctuating traffic are presented. The System Control Software development cycle, consisting of top level design, which includes functional decomposition and software module structure, detailed design, integration and testing phases, is discussed. Various functional flow diagrams are provided illustrating the information interfaces to external communications, inter-component communications, the network database and the physical devices. An example illustrating the performance of power control and traffic control software is presented.

  6. Cirrus cloud-temperature interactions over a tropical station, Gadanki from lidar and satellite observations

    SciTech Connect

    S, Motty G Satyanarayana, M. Krishnakumar, V. Dhaman, Reji k.

    2014-10-15

    The cirrus clouds play an important role in the radiation budget of the earth's atmospheric system and are important to characterize their vertical structure and optical properties. LIDAR measurements are obtained from the tropical station Gadanki (13.5{sup 0} N, 79.2{sup 0} E), India, and meteorological indicators derived from Radiosonde data. Most of the cirrus clouds are observed near to the tropopause, which substantiates the strength of the tropical convective processes. The height and temperature dependencies of cloud height, optical depth, and depolarization ratio were investigated. Cirrus observations made using CALIPSO satellite are compared with lidar data for systematic statistical study of cirrus climatology.

  7. System architecture for an advanced Canadian communications satellite demonstration mission

    NASA Astrophysics Data System (ADS)

    Takats, P.; Irani, S.

    1992-03-01

    An advanced communications satellite system that provides single hop interconnectivity and interworking for both a personal communications network and an advanced private business network in the Ka and Ku bands respectively, is presented. An overall network perspective is discussed that studies the interface of such an advanced satellite communication system to the terrestrial network in the context of the Open Systems Interconnection model. It is shown that this proposed satellite system can dynamically establish links and efficiently allocate the satellite resource amongst the user terminal population for a mix of data and voice traffic.

  8. Alternative force structuring strategies for military satellite communication systems

    NASA Astrophysics Data System (ADS)

    Murdock, William P., Jr.

    1987-12-01

    The purpose of this study was to determine and examine alternative force structuring strategies for military satellite communication (MILSATCOM) systems. The study was undertaken due to the United States' reliance on relatively few, expensive satellites as critical communication links. Current anti-satellite weapons pose a definite threat to missions using this type of strategy. In response to this situation, proliferated MILSATCOM designs using low Earth circular orbits and a highly elliptical (Molniya) orbit were defined and analyzed. The objective of this effort was to compare the proliferated alternative systems' performance and cost with a current MILSATCOM system. The Fleet Satellite Communication (FLTSATCOM) system was used as the baseline system for comparison. Overall, both alternative force structuring strategies provided superior Earth coverage when subjected to satellite losses. This was especially evident in the European and Mideast theaters. The Molyniya constellation was the best alternative when considering system performance, system cost, current MILSATCOM system compatibility and the technology required for system implementation.

  9. Daily OLR Climate Data Record - A Challenge to Homogenize Operational Satellite Observations for Climate Applications

    NASA Astrophysics Data System (ADS)

    Lee, Hai-Tien

    2014-05-01

    A data set of daily mean outgoing longwave radiation (OLR) at 1°x1° grid spanning from 1979 to 2012 was generated using infrared radiance observations from the High resolution Infrared Radiation Sounder (HIRS) and Imaging instruments onboard the international operational polar-orbiting and geostationary satellites. The instantaneous OLR can be accurately estimated by the multi-spectral regression model using narrow band radiance observations (Ellingson et al., 1989), however, there are challenges for constructing a climate data record that is homogeneous in both space and time, while maintaining radiometric accuracy. The synergy of polar-orbiting and geostationary observation systems provides advantages that much improve the homogeneity of the temporal and spatial sampling. Bias correction methodologies have been devised to maintain the radiometric accuracy. The HIRS OLR algorithm is revised to handle the problems caused by the configuration variations in the HIRS instruments over time. This removes scene-dependent inter-satellite biases. Incorporating OLR estimated from Imager instruments onboard geostationary satellites not only sufficiently resolves the diurnal variation that is critical for daily integral purpose, but it also helps to remove the artificial trends resulted from the polar-orbiter's orbital drift effects. This work produced a continuous daily OLR climate data record of more than three decades that can be very useful for climate variation and numerical model simulation assessment purposes.

  10. Improving the Transition of Earth Satellite Observations from Research to Operations

    NASA Technical Reports Server (NTRS)

    Goodman, Steven J.; Lapenta, William M.; Jedlovec, Gary J.

    2004-01-01

    There are significant gaps between the observations, models, and decision support tools that make use of new data. These challenges include: 1) Decreasing the time to incorporate new satellite data into operational forecast assimilation systems, 2) Blending in-situ and satellite observing systems to produce the most accurate and comprehensive data products and assessments, 3) Accelerating the transition from research to applications through national test beds, field campaigns, and pilot demonstrations, and 4) Developing the partnerships and organizational structures to effectively transition new technology into operations. At the Short-term Prediction Research and Transition (SPORT) Center in Huntsville, Alabama, a NASA-NOAA-University collaboration has been developed to accelerate the infusion of NASA Earth science observations, data assimilation and modeling research into NWS forecast operations and decision-making. The SPoRT Center research focus is to improve forecasts through new observation capability and the regional prediction objectives of the US Weather Research Program dealing with 0-1 day forecast issues such as convective initiation and 24-hr quantitative precipitation forecasting. The near real-time availability of high-resolution experimental products of the atmosphere, land, and ocean from the Moderate Resolution Imaging Spectroradiometer (MODIS), the Advanced Infrared Spectroradiometer (AIRS), and lightning mapping systems provide an opportunity for science and algorithm risk reduction, and for application assessment prior to planned observations from the next generation of operational low Earth orbiting and geostationary Earth orbiting satellites. This paper describes the process for the transition of experimental products into forecast operations, current products undergoing assessment by forecasters, and plans for the future. The SPoRT Web page is at (http://www.ghcc.msfc.nasa.gov/sport).

  11. Interleaved Observation Execution and Rescheduling on Earth Observing Systems

    NASA Technical Reports Server (NTRS)

    Khatib, Lina; Frank, Jeremy; Smith, David; Morris, Robert; Dungan, Jennifer

    2003-01-01

    Observation scheduling for Earth orbiting satellites solves the following problem: given a set of requests for images of the Earth, a set of instruments for acquiring those images distributed on a collecting of orbiting satellites, and a set of temporal and resource constraints, generate a set of assignments of instruments and viewing times to those requests that satisfy those constraints. Observation scheduling is often construed as a constrained optimization problem with the objective of maximizing the overall utility of the science data acquired. The utility of an image is typically based on the intrinsic importance of acquiring it (for example, its importance in meeting a mission or science campaign objective) as well as the expected value of the data given current viewing conditions (for example, if the image is occluded by clouds, its value is usually diminished). Currently, science observation scheduling for Earth Observing Systems is done on the ground, for periods covering a day or more. Schedules are uplinked to the satellites and are executed rigorously. An alternative to this scenario is to do some of the decision-making about what images are to be acquired on-board. The principal argument for this capability is that the desirability of making an observation can change dynamically, because of changes in meteorological conditions (e.g. cloud cover), unforeseen events such as fires, floods, or volcanic eruptions, or un-expected changes in satellite or ground station capability. Furthermore, since satellites can only communicate with the ground between 5% to 10% of the time, it may be infeasible to make the desired changes to the schedule on the ground, and uplink the revisions in time for the on-board system to execute them. Examples of scenarios that motivate an on-board capability for revising schedules include the following. First, if a desired visual scene is completely obscured by clouds, then there is little point in taking it. In this case, satellite resources, such as power and storage space can be better utilized taking another image that is higher quality. Second, if an unexpected but important event occurs (such as a fire, flood, or volcanic eruption), there may be good reason to take images of it, instead of expending satellite resources on some of the lower priority scheduled observations. Finally, if there is unexpected loss of capability, it may be impossible to carry out the schedule of planned observations. For example, if a ground station goes down temporarily, a satellite may not be able to free up enough storage space to continue with the remaining schedule of observations. This paper describes an approach for interleaving execution of observation schedules with dynamic schedule revision based on changes to the expected utility of the acquired images. We describe the problem in detail, formulate an algorithm for interleaving schedule revision and execution, and discuss refinements to the algorithm based on the need for search efficiency. We summarize with a brief discussion of the tests performed on the system.

  12. 1993 Earth Observing System reference handbook

    NASA Technical Reports Server (NTRS)

    Asrar, Ghassem (editor); Dokken, David Jon (editor)

    1993-01-01

    Mission to Planet Earth (MTPE) is a NASA-sponsored concept that uses space- and ground-based measurement systems to provide the scientific basis for understanding global change. The space-based components of MTPE will provide a constellation of satellites to monitor the Earth from space. Sustained observations will allow researchers to monitor climate variables overtime to determine trends; however, space-based monitoring alone is not sufficient. A comprehensive data and information system, a community of scientists performing research with the data acquired, and extensive ground campaigns are all important components. Brief descriptions of the various elements that comprise the overall mission are provided. The Earth Observing System (EOS) - a series of polar-orbiting and low-inclination satellites for long-term global observations of the land surface, biosphere, solid Earth, atmosphere, and oceans - is the centerpiece of MTPE. The elements comprising the EOS mission are described in detail.

  13. Ionospheric electron density irregularities observed by satellite-to-satellite, dual-frequency, low-low Doppler tracking link

    NASA Technical Reports Server (NTRS)

    Estes, R. D.; Grossi, M. D.

    1984-01-01

    A low-low, satellite-to-satellite, dual-frequency, Doppler tracking experiment was performed. The data are analyzed here for irregularities in electron density at the altitude of 212 km. The differential Doppler data with the relative motion term removed are integrated to obtain a representation of the electron density variation along the satellite path. Well-known large-scale features such as the equatorial geomagnetic anomaly and day/night ionization level differences are clearly observed in the integrated data. The larger crest of the morning geomagnetic anomaly is seen to occur in the southern (winter) hemisphere in agreement with previous observations. In addition, a sharp peak in the electron density at the day-to-night transition point is observed in two consecutive revolutions. This effect may be due to the previously postulated atmospheric shock wave generated by supersonic motion of the terminator.

  14. DCS: A global satellite environmental data collection system study

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Cost analysis and technical feasibility data are presented on five medium orbiting and six geosynchronous satellite data collection systems with varying degrees of spacecraft and local user terminal complexity. Data are also provided on system approaches, user requirements, and user classes. Systems considered include orbiting ERTS and EOS type satellites and geosynchronous SmS and SEOS type data collectors.

  15. Feasibility of microminiature satellites

    NASA Astrophysics Data System (ADS)

    Imai, Ryouichi

    1991-07-01

    A conceptual study is conducted on technical problems and system design techniques to accomplish higher performance microminiature satellites by smaller systems. Applications of microminiature satellite technology to practical satellite mission are mentioned. Concepts of microminiature satellites, measures to miniaturize satellites, and micro-miniaturization technologies for communication and data processing, electric solar power paddle, attitude and orbit control, structure, thermal control, propulsion, and instrumentation systems are outlined. Examples of miniaturizing satellite missions such as planet exploration, low-altitude communication networks, space positioning system, low-altitude earth observation mission, clustered satellites, tethered satellites, and timely observation are described. Satellite miniaturizing technology can also be used to launch systems by lasers, and superconductive linear catapults (space escalator). It is pointed out that keys to promote satellite miniaturization are electronics, precision machining, raw material, electric power source technologies, and system design technology to integrate those technologies.

  16. Observations of satellite environment on ETS-V of Japan

    NASA Astrophysics Data System (ADS)

    Nishimoto, Hironobu; Matsumoto, Haruhisa; Fukuda, Toshiyuki

    This paper present the results of space and spacecraft environment measurements from the Technical Acquisition Equipment (TEDA) on the Engineering TEST Satellite-V (ETS-V). An empirical model is proposed to analyze the characteristics of spacecraft environments.

  17. An observational philosophy for GEOS-C satellite altimetry

    NASA Technical Reports Server (NTRS)

    Weiffenbach, G. C.

    1972-01-01

    The parameters necessary for obtaining a 10 cm accuracy for GEOS-C satellite altimetry are outlined. These data include oceanographic parameters, instrument calibration, pulse propagation, sea surface effects, and optimum design.

  18. Texstar: The all-Texas educational satellite system

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Longhorn Satellite Company (LSC) has designed Texstar, and educational satellite communications system which will be considered as a means of equalizing the distribution of educational resources throughout the state of Texas. Texstar will be capable of broadcasting live lectures and documentaries in addition to transmitting data from a centralized receiving-transmitting station. Included in the design of Texstar is the system and subsystem design for the satellite and the design of the ground stations. The launch vehicle used will be the Texas-built Conestoga 421-48. The Texstar system incorporates three small satellites in slightly inclined geosynchronous orbits. Due to the configuration and spacing of these satellites, the system will be accessed as if it were one large, geostationary satellite. Texstar is shown to be a viable option to the educational crisis in the state of Texas.

  19. Landsat--Earth Observation Satellites Since 1972, Landsat satellites have continuously acquired space-

    E-print Network

    reception, data archiving, product generation, and data distribution. The result of this program the sunlit side of the Earth in a sun synchronous orbit. Each satellite makes a complete orbit every 99

  20. Estimation of the cirrus cloud scattering phase function from satellite observations

    E-print Network

    Baum, Bryan A.

    Estimation of the cirrus cloud scattering phase function from satellite observations Chenxi Wang: Thin cirrus clouds Optical properties Cloud phase function Satellite observations a b s t r a c columns provide the best match for cirrus clouds over ocean, whereas droxtals may exist in optically thin

  1. Solar power satellite system definition study, volume 4, phase 2

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Results of an overall evaluation of the solar power satellite concept are reported. Specific topics covered include: solid state sandwich configuration; parametric development of reliability design; power distribution system for solid state solar power satellites; multibeam transmission; GEO base system configuration; suppression of the heavy lift launch vehicle trajectory; conceptual design of an offshore space center facility; solar power satellite development and operations scenario; and microwave power transmission technology, advancement, development, and facility requirements.

  2. Comparison between GPS radio occultation electron densities and in situ satellite observations

    NASA Astrophysics Data System (ADS)

    Pedatella, N. M.; Yue, X.; Schreiner, W. S.

    2015-06-01

    Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) Global Positioning System (GPS) radio occultation (RO) electron densities are compared with collocated in situ observations from the CHAllenging Minisatellite Payload (CHAMP) and Communications/Navigation Outage Forecasting System (C/NOFS) satellites. The comparison is restricted to observations occurring within 2° latitude and longitude and 15 min local time. The in situ observations occur at altitudes of ˜300-800 km, and the results of the present study represent the first global comparison of COSMIC electron densities at altitudes ranging from near the F region peak to the topside ionosphere. The correlation coefficient between the COSMIC and in situ observations is greater than 0.90, indicating an overall good agreement between GPS RO electron densities and CHAMP and C/NOFS satellite observations. Furthermore, when averaged over all latitudes and local times, we find a near-zero mean bias and root-mean-square difference of typically less than ±30% between the COSMIC electron densities and collocated in situ observations. The overall good agreement demonstrates that the COSMIC GPS RO observations provide an accurate measure of electron density in the topside ionosphere. The results also reveal a systematic structure to the error in the equatorial and low-latitude daytime ionosphere. This structure is related to the equatorial ionization anomaly and is consistent with the error introduced by the Abel inversion spherical symmetry assumption used to retrieve the COSMIC electron density profiles. The present study thus provides direct observational evidence of the Abel inversion error on GPS RO electron densities.

  3. Evaluation of sulfate aerosol optical depths over the North Atlantic and comparison with satellite observations

    SciTech Connect

    Berkowitz, C.M.; Ghan, S.J.; Benkovitz, C.M.; Wagener, R.; Nemesure, S.; Schwartz, S.E.

    1993-11-01

    It has been postulated that scattering of sunlight by aerosols can significantly reduce the amount of solar energy absorbed by the climate system. Aerosol measurement programs alone cannot provide all the information needed to evaluate the radiative forcing due to anthropogenic aerosols. Thus, comprehensive global-scale aerosol models, properly validated against surface-based and satellite measurements, are a fundamental tool for evaluating the impacts of aerosols on the planetary radiation balance. Analyzed meteorological fields from the European Centre for Medium-Range Weather Forecasts are used to drive a modified version of the PNL Global Chemistry Model, applied to the atmospheric sulfur cycle. The resulting sulfate fields are used to calculate aerosol optical depths, which in turn are compared to estimates of aerosol optical depth based on satellite observations.

  4. Climate Observing Systems: Data System Challenges

    NASA Astrophysics Data System (ADS)

    Karl, T. R.

    2001-12-01

    Existing observing and data systems have provided considerable information about past climate variations and changes. The recent reports by the Intergovernmental Panel on Climate Change, the National Research Council, and the USGCRP National Assessment of Climate Variability and Change are testaments to a vast array of knowledge. These reports also expose some serious deficiencies in our ability to discern past climate variations and change which lead to substantial uncertainties in key climate state, climate feedback, and climate forcing variables. How significant are these uncertainties? For climate trends that have our highest confidence, like the change in mean global surface temperature, the 95 percent confidence intervals amount to about two-thirds of the calculated change. With such large uncertainties it is exceedingly difficult to discern accelerated changes. For other variables, especially variables related to climate feedbacks and forcings (with exceptions for long-lived and well-mixed greenhouse gases like CO2 or CH4) or climate and weather extremes, we often have little or no information to discern trends or cannot objectively assess confidence intervals. Do we know how to reduce existing uncertainties? First and foremost, a climate observation oversight and monitoring capability is needed that tracks the gathering of the data, the processing system, and the performance of the observations, especially time-dependent biases. An organized capability does not now exist, but could be developed at a new and/or existing centers. This center(s) should then have the means and influence to fix problems and be able to establish requirements for new in-situ and satellite observing including related data systems. Such a capability should complement the following: (1) Climate observations from both space-based and in-situ platforms that are taken in ways that address climate needs and adhere to the ten principles outlined by the NRC (1999 Adequacy of Climate Observing Systems) and GCOS. An international framework is vital. (2) A global telecommunications network and satellite data telemetry capacity to enable data and products to be disseminated. (3) A climate observations analysis capability that produces global and regional analyses of various products for the atmosphere, oceans, land surface and hydrology, and the cryosphere. (4) Four dimensional data assimilation capabilities that process the multivariate data in a physically consistent framework to enable production of the analyses, not just for the atmosphere but also for the oceans, land surface and so on. (5) Global climate models that encompass all parts of the climate system and which are utilized to design effective sampling strategies and evaluate observations. These improvements primarily relate to the data system, after the observation has been made, but they must be accompanied with a concerted effort to improve our instrumentation, platforms, and sampling resolutions for key climate variables. How much would such a data system cost? Practical experience has shown that an effective archive and access system can be designed for about 5 to 10 percent of the total cost of the observing system. Building on a solid investment in data management infrastructure and hardware (including data quality control, access, and long-term stewardship), a comparable investment would be required to address oversight, monitoring, data analysis, data assimilation, and adherence to the ten principles. An implementation time frame on the order of five to ten years is probably a realistic time frame, similar to the planning and implementation horizon of major new observing systems.

  5. Feature Detection Systems Enhance Satellite Imagery

    NASA Technical Reports Server (NTRS)

    2009-01-01

    In 1963, during the ninth orbit of the Faith 7 capsule, astronaut Gordon Cooper skipped his nap and took some photos of the Earth below using a Hasselblad camera. The sole flier on the Mercury-Atlas 9 mission, Cooper took 24 photos - never-before-seen images including the Tibetan plateau, the crinkled heights of the Himalayas, and the jagged coast of Burma. From his lofty perch over 100 miles above the Earth, Cooper noted villages, roads, rivers, and even, on occasion, individual houses. In 1965, encouraged by the effectiveness of NASA s orbital photography experiments during the Mercury and subsequent Gemini manned space flight missions, U.S. Geological Survey (USGS) director William Pecora put forward a plan for a remote sensing satellite program that would collect information about the planet never before attainable. By 1972, NASA had built and launched Landsat 1, the first in a series of Landsat sensors that have combined to provide the longest continuous collection of space-based Earth imagery. The archived Landsat data - 37 years worth and counting - has provided a vast library of information allowing not only the extensive mapping of Earth s surface but also the study of its environmental changes, from receding glaciers and tropical deforestation to urban growth and crop harvests. Developed and launched by NASA with data collection operated at various times by the Agency, the National Oceanic and Atmospheric Administration (NOAA), Earth Observation Satellite Company (EOSAT, a private sector partnership that became Space Imaging Corporation in 1996), and USGS, Landsat sensors have recorded flooding from Hurricane Katrina, the building boom in Dubai, and the extinction of the Aral Sea, offering scientists invaluable insights into the natural and manmade changes that shape the world. Of the seven Landsat sensors launched since 1972, Landsat 5 and Landsat 7 are still operational. Though both are in use well beyond their intended lifespans, the mid-resolution satellites, which provide the benefit of images detailed enough to reveal large features like highways while still broad enough for global coverage, continue to scan the entirety of the Earth s surface. In 2012, NASA plans to launch the Landsat Data Continuity Mission (LDCM), or Landsat 8, to extend the Landsat program s contributions to cartography, water management, natural disaster relief planning, and more.

  6. Retrieval of Aerosol Absorption Properties from Satellite Observations

    NASA Technical Reports Server (NTRS)

    Torres, Omar; Bhartia, Pawan K.; Jethva, H.; Ahn, Chang-Woo

    2012-01-01

    The Angstrom Absorption Exponent (AAE) is a parameter commonly used to characterize the wavelength-dependence of aerosol absorption optical depth (AAOD). It is closely related to aerosol composition. Black carbon (BC) containing aerosols yield AAE values near unity whereas Organic carbon (OC) aerosol particles are associated with values larger than 2. Even larger AAE values have been reported for desert dust aerosol particles. Knowledge of spectral AAOD is necessary for the calculation of direct radiative forcing effect of aerosols and for inferring aerosol composition. We have developed a satellitebased method of determining the spectral AAOD of absorbing aerosols. The technique uses multi-spectral measurements of upwelling radiation from scenes where absorbing aerosols lie above clouds as indicated by the UV Aerosol Index. For those conditions, the satellite measurement can be explained, using an approximations of Beer's Law (BL), as the upwelling reflectance at the cloud top attenuated by the absorption effects of the overlying aerosol layer. The upwelling reflectance at the cloud-top in an aerosol-free atmospheric column is mainly a function of cloud optical depth (COD). In the proposed method of AAE derivation, the first step is determining COD which is retrieved using a previously developed color-ratio based approach. In the second step, corrections for molecular scattering effects are applied to both the observed ad the calculated cloud reflectance terms, and the spectral AAOD is then derived by an inversion of the BL approximation. The proposed technique will be discussed in detail and application results making use of OMI multi-spectral measurements in the UV-Vis. will be presented.

  7. The Martian satellites - 100 years on. [Phobos and Deimos observational history

    NASA Technical Reports Server (NTRS)

    Hunt, G. E.; Michael, W. H., Jr.; Pascu, D.; Veverka, J.; Wilkins, G. A.; Woolfson, M.

    1978-01-01

    Studies of Phobos and Deimos, the two satellites of Mars, may provide the best observations yet of the material populating the asteroid belt. Viking observations of Phobos showing crater chains and striations are analyzed, and Mariner-9 photometry exhibiting the albedo of the satellite is discussed. A mass determination for Phobos results in a value of 1.1 times 10 to the 19th power g; the mean density of the satellite is set at about 2 g per cu cm, a value suggesting formation of the satellite from material in the asteroid belt.

  8. Engineering calculations for communications satellite systems planning

    NASA Technical Reports Server (NTRS)

    Walton, E.; Aebker, E.; Mata, F.; Reilly, C.

    1991-01-01

    The final phase of a satellite synthesis project is described. Several methods for generating satellite positionings with improved aggregate carrier to interference characteristics were studied. Two general methods for modifying required separation values are presented. Also, two methods for improving aggregate carrier to interference (C/I) performance of given satellite synthesis solutions are presented. A perturbation of the World Administrative Radio Conference (WARC) synthesis is presented.

  9. Cloud cover as derived from surface observations, sunshine duration, and satellite observations

    SciTech Connect

    Moriarty, W.W. )

    1991-01-01

    The proportion of the sky visibly covered by low and middle level clouds increases towards the horizon, due to their vertical extent, and this was considered in relation to its effect on direct solar radiation. The increase was found as a function of elevation above the horizon and of cloud amount, and it was shown to follow from its functional form that photographs from polar-orbiting satellites would give lower estimates of cloud cover than ground observations, and so would sunshine duration measurements in low latitudes. In high latitudes sunshine duration would yield higher estimates than ground observations. Other investigators had found that both the other methods gave lower estimates than surface observations at all latitudes, and the discrepancies were larger than those in this study. The differing results could be seen as due at least in part to differing treatments of high cloud.

  10. Satellite Power System (SPS) financial/management scenarios

    NASA Technical Reports Server (NTRS)

    Vajk, J. P.

    1978-01-01

    The possible benefits of a Satellite Power System (SPS) program, both domestically and internationally, justify detailed and imaginative investigation of the issues involved in financing and managing such a large-scale program. In this study, ten possible methods of financing a SPS program are identified ranging from pure government agency to private corporations. The following were analyzed and evaluated: (1) capital requirements for SPS; (2) ownership and control; (3) management principles; (4) organizational forms for SPS; (5) criteria for evaluation; (6) detailed description and preliminary evaluation of alternatives; (7) phased approaches; and (8) comparative evaluation. Key issues and observations and recommendations for further study are also presented.

  11. KAGLVis - On-line 3D Visualisation of Earth-observing-satellite Data

    NASA Astrophysics Data System (ADS)

    Szuba, Marek; Ameri, Parinaz; Grabowski, Udo; Maatouki, Ahmad; Meyer, Jörg

    2015-04-01

    One of the goals of the Large-Scale Data Management and Analysis project is to provide a high-performance framework facilitating management of data acquired by Earth-observing satellites such as Envisat. On the client-facing facet of this framework, we strive to provide visualisation and basic analysis tool which could be used by scientists with minimal to no knowledge of the underlying infrastructure. Our tool, KAGLVis, is a JavaScript client-server Web application which leverages modern Web technologies to provide three-dimensional visualisation of satellite observables on a wide range of client systems. It takes advantage of the WebGL API to employ locally available GPU power for 3D rendering; this approach has been demonstrated to perform well even on relatively weak hardware such as integrated graphics chipsets found in modern laptop computers and with some user-interface tuning could even be usable on embedded devices such as smartphones or tablets. Data is fetched from the database back-end using a ReST API and cached locally, both in memory and using HTML5 Web Storage, to minimise network use. Computations, calculation of cloud altitude from cloud-index measurements for instance, can depending on configuration be performed on either the client or the server side. Keywords: satellite data, Envisat, visualisation, 3D graphics, Web application, WebGL, MEAN stack.

  12. Cloud invigoration and suppression by aerosols over the tropical region based on satellite observations

    NASA Astrophysics Data System (ADS)

    Niu, F.; Li, Z.

    2011-02-01

    Aerosols may modify cloud properties and precipitation via a variety of mechanisms with varying and contradicting consequences. Using a large ensemble of satellite data acquired by the Moderate Resolution Imaging Spectroradiometer onboard the Earth Observing System's Aqua platform, the CloudSat cloud profiling radar and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite over the tropical oceans, we identified two distinct responses of clouds and precipitation to increases in aerosol loading. Cloud-top temperatures decrease significantly with increasing aerosol index (AI) over oceans and aerosol optical depth (AOT) over land for mixed-phase clouds with warm cloud bases; no significant changes were found for liquid clouds. The distinct responses are explained by two mechanisms, namely, the aerosol invigoration effect and the microphysical effect. Aerosols can significantly invigorate convection mainly through ice processes, while precipitation from liquid clouds is suppressed through aerosol microphysical processes. Precipitation rates are found to increase with AI for mixed-phase clouds, but decrease for liquid clouds, suggesting that the dominant effect differs for the two types of clouds. These effects change the overall distribution of precipitation rates, leading to more or heavier rains in dirty environments than in cleaner ones.

  13. Computer-Aided Communication Satellite System Analysis and Optimization.

    ERIC Educational Resources Information Center

    Stagl, Thomas W.; And Others

    Various published computer programs for fixed/broadcast communication satellite system synthesis and optimization are discussed. The rationale for selecting General Dynamics/Convair's Satellite Telecommunication Analysis and Modeling Program (STAMP) in modified form to aid in the system costing and sensitivity analysis work in the Program on…

  14. System requirements for laser power beaming to geosynchronous satellites

    SciTech Connect

    Neal, R.D.; McKechnie, T.S.; Neal, D.R.

    1994-03-01

    Geosynchronous satellites use solar arrays as their primary source of electrical power. During earth eclipse, which occurs 90 times each year, the satellites are powered by batteries, but the heavy charge-discharge cycle decreases their life expectancy. By beaming laser power to satellites during the eclipses, satellite life expectancy can be significantly increased. In this paper, the authors investigate the basic system parameters and trade-offs of using reactor pumped laser technology to beam power from the Nevada Test Site. A first order argument is used to develop a consistent set of requirements for such a system.

  15. Earth Observatory Satellite system definition study. Report 5: System design and specifications. Volume 2: EOS-A system specification

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The objectives of the Earth Observatory Satellite (EOS) program are defined. The system specifications for the satellite payload are examined. The broad objectives of the EOS-A program are as follows: (1) to develop space-borne sensors for the measurement of land resources, (2) to evolve spacecraft systems and subsystems which will permit earth observation with greater accuracy, coverage, spatial resolution, and continuity than existing systems, (3) to develop improved information processing, extraction, display, and distribution systems, and (4) to use space transportation systems for resupply and retrieval of the EOS.

  16. Satellite services system analysis study. Volume 3: Service equipment requirements

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Service equipment mission requirements are discussed. On-orbit operations, satellite classes, and reference missions are included. Service equipment usage and requirements are considered. Equipment identification methodology is discussed. Service equipment usage is analyzed, including initial launch, revisit, Earth return, and orbital storage. A summary of service requirements and equipment is presented, including service equipment status, even interaction, satellite features, and observations.

  17. Engineering calculations for communications satellite systems planning

    NASA Technical Reports Server (NTRS)

    Levis, C. A.; Martin, C. H.; Reilly, C. H.; Gonsalvez, D. J.; Yamaura, Y.

    1985-01-01

    An extended gradient search code for broadcasting satellite service (BSS) spectrum/orbit assignment synthesis is discussed. Progress is also reported on both single-entry and full synthesis computational aids for fixed satellite service (FSS) spectrum/orbit assignment purposes.

  18. Adding a Mission to the Joint Polar Satellite System (JPSS) Common Ground System (CGS)

    NASA Astrophysics Data System (ADS)

    Miller, S. W.; Grant, K. D.; Jamilkowski, M. L.

    2014-12-01

    The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation civilian weather and environmental satellite system: the Joint Polar Satellite System (JPSS). The Joint Polar Satellite System will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA. The JPSS satellites will carry a suite of sensors designed to collect meteorological, oceanographic, climatological and geophysical observations of the Earth. The ground processing system for JPSS is known as the JPSS Common Ground System (JPSS CGS). Developed and maintained by Raytheon Intelligence, Information and Services (IIS), the CGS is a multi-mission enterprise system serving NOAA, NASA and their national and international partners. The CGS provides a wide range of support to a number of missions: 1) Command and control and mission management for the Suomi National Polar-orbiting Partnership (S-NPP) mission today, expanding this support to the JPSS-1 satellite and the Polar Free Flyer mission in 2017 2) Data acquisition via a Polar Receptor Network (PRN) for S-NPP, the Japan Aerospace Exploration Agency's (JAXA) Global Change Observation Mission - Water (GCOM-W1), POES, and the Defense Meteorological Satellite Program (DMSP) and Coriolis/WindSat for the Department of Defense (DoD) 3) Data routing over a global fiber Wide Area Network (WAN) for S-NPP, JPSS-1, Polar Free Flyer, GCOM-W1, POES, DMSP, Coriolis/WindSat, the NASA Space Communications and Navigation (SCaN, which includes several Earth Observing System [EOS] missions), MetOp for the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), and the National Science Foundation (NSF) 4) Environmental data processing and distribution for S-NPP, GCOM-W1 and JPSS-1 With this established infrastructure and existing suite of missions, the CGS is extensible to a wider array of potential new missions. This paper will describe the basic steps for adding a mission to the CGS, addressing the existing types of support defined above.

  19. Synchronization of system-of-systems interfaces in military satellite communications

    E-print Network

    Davis, Mark J. (Mark Jeffrey)

    2008-01-01

    Military systems continue to become more complex and nearly all are now part of one or more system of systems (SoS). Military satellite communications programs have expanded over the last decade from three distinct satellite ...

  20. Committee on Earth Observation Satellites (CEOS) perspectives about the GEO Supersite initiative

    NASA Astrophysics Data System (ADS)

    Lengert, Wolfgang; Zoffoli, Simona; Giguere, Christine; Hoffmann, Joern; Lindsay, Francis; Seguin, Guy

    2014-05-01

    This presentation is outlining the effort of the Committee on Earth Observation Satellites (CEOS) using its global collaboration structure to support implementing the GEO priority action DI-01 Informing Risk Management and Disaster Reduction addressing the component: C2 Geohazards Monitoring, Alert, and Risk Assessment. A CEOS Supersites Coordination Team (SCT) has been established in order to make best use of the CEOS global satellite resources. For this, the CEOS SCT has taken a holistic view on the science data needs and availability of resources, considering the constraints and exploitation potentials of synergies. It is interfacing with the Supersites Science Advisory Group and the Principle Investigators to analyze how the satellite data associated with seismic and Global Navigation Satellite System (GNSS) data can support national authorities and policy makers in risk assessment and the development of mitigation strategies. CEOS SCT aims to support the establishment of a fully integrated approach to geohazards monitoring, based on collaboration among existing networks and international initiatives, using new instrumentation such as in-situ sensors, and aggregating space (radar, optical imagery) and ground-based (subsurface) observations. The three Supersites projects which are funded under the EC FP7 action, namely (i) FUTUREVOLC: A European volcanological supersite in Iceland: a monitoring system and network for the future Geohazards Monitoring, Alert, and Risk Assessment, (ii) MARsite: New Directions in Seismic Hazard assessment through Focused Earth Observation in the Marmara Supersite, (iii) MED-SUV: MEDiterranean Volcanoes and related seismic risks, have been examined as a vehicle to fulfill these ambitious objectives. FUTUREVOLC has already been granted CEOS support. This presentation will outline CEOS agreed process and criteria applied by the Supersites Coordination Team (SCT), for selecting these Supersites in the context of the GSNL initiative, as well provide information about the satellite data provided by CEOS for the different Supersites. ASI - COSMO-Skymed CNES - SPOT-5, Pleiades CSA - Radarsat-2 DLR - TerraSAR-X, TanDEM-X ESA - ERS-1/2, Envisat, Sentinel (on behalf of EC - Copernicus) JAXA - ALOS-2, ALOS-1, J-ERS NASA - ASTER

  1. Evaluation of CDMA system capacity for mobile satellite system applications

    NASA Technical Reports Server (NTRS)

    Smith, Partrick O.; Geraniotis, Evaggelos A.

    1988-01-01

    A specific Direct-Sequence/Pseudo-Noise (DS/PN) Code-Division Multiple-Access (CDMA) mobile satellite system (MSAT) architecture is discussed. The performance of this system is evaluated in terms of the maximum number of active MSAT subscribers that can be supported at a given uncoded bit-error probability. The evaluation decouples the analysis of the multiple-access capability (i.e., the number of instantaneous user signals) from the analysis of the multiple-access mutliplier effect allowed by the use of CDMA with burst-modem operation. We combine the results of these two analyses and present numerical results for scenarios of interest to the mobile satellite system community.

  2. ASPECTS OF ARCTIC SEA ICE OBSERVABLE BY SEQUENTIAL PASSIVE MICROWAVE OBSERVATIONS FROM THE NIMBUS-5 SATELLITE.

    USGS Publications Warehouse

    Campbell, William J.; Gloersen, Per; Zwally, H. Jay

    1984-01-01

    Observations made from 1972 to 1976 with the Electrically Scanning Microwave Radiometer on board the Nimbus-5 satellite provide sequential synoptic information of the Arctic sea ice cover. This four-year data set was used to construct a fairly continuous series of three-day average 19-GHz passive microwave images which has become a valuable source of polar information, yielding many anticipated and unanticipated discoveries of the sea ice canopy observed in its entirety through the clouds and during the polar night. Short-term, seasonal, and annual variations of key sea ice parameters, such as ice edge position, ice types, mixtures of ice types, ice concentrations, and snow melt on the ice, are presented for various parts of the Arctic.

  3. Geodetic positioning using a global positioning system of satellites

    NASA Technical Reports Server (NTRS)

    Fell, P. J.

    1980-01-01

    Geodetic positioning using range, integrated Doppler, and interferometric observations from a constellation of twenty-four Global Positioning System satellites is analyzed. A summary of the proposals for geodetic positioning and baseline determination is given which includes a description of measurement techniques and comments on rank deficiency and error sources. An analysis of variance comparison of range, Doppler, and interferometric time delay to determine their relative geometric strength for baseline determination is included. An analytic examination to the effect of a priori constraints on positioning using simultaneous observations from two stations is presented. Dynamic point positioning and baseline determination using range and Doppler is examined in detail. Models for the error sources influencing dynamic positioning are developed. Included is a discussion of atomic clock stability, and range and Doppler observation error statistics based on random correlated atomic clock error are derived.

  4. Satellite communications systems and technology. Volume 1: Analytical chapters

    NASA Technical Reports Server (NTRS)

    Edelson, Burton I. (editor); Pelton, Joseph N. (editor); Bostian, Charles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Helm, Neil R.; Jennings, Raymond D.; Kwan, Robert K.; Mahle, Christoph E.

    1993-01-01

    This is Volume 1 (Analytical Chapters) of the final report of the NASA/NSF Panel Satellite Communications Systems and Technology. The panel surveyed advanced technology being developed for commercial use in the satellite communications field in Europe, Japan, and Russia. All aspects of satellite communications were considered, including fixed, broadcast, mobile, personal communications, navigation, low earth orbit, and small satellites. The focus was on experimental and advanced technology being developed in R&D and demonstration programs rather than on today's production capabilities. Focus was on commercial satellite technology, and does not review defense-related or other confidential satellite communications capabilities. The NASA/NSF panel concluded that the United States has lost its leading position in many critical satellite communications technologies. Although U.S. industry retains a leading position in today's marketplace for satellite communications systems and services, this position is largely founded on technologies and capabilities developed in the 1960's and 1970's. Because the United States is losing ground with respect to a wide range of technologies and systems that will be key to future communications markets, the market share of the U.S. satellite communications industry is at risk.

  5. Satellite communications systems and technology. Volume 1; Analytic Chapters

    NASA Technical Reports Server (NTRS)

    Jennings, Raymond D.; Mahle, Christoph E.; Miller, Edward F.; Riley, Lance; Pelton, Joseph N.; Bostian, Charles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Edelson, Burton I.; Kwan, Robert K.; Helm, Neil R.

    1993-01-01

    Volume 1 (Analytical Chapters) of the final report of the NASA/NSF Panel Satellite Communications Systems and Technology is presented. The panel surveyed advanced technology being developed for commercial use in the satellite communications field in Europe, Japan, and Russia. All aspects of satellite communications were considered, including fixed, broadcast, mobile, personal communications, navigation, low earth orbit, and small satellites. The focus of the study was on experimental and advanced technology being developed in R&D and demonstration programs rather than on today's production capabilities. The report focuses on commercial satellite technology, and does not review defense-related or other confidential satellite communications capabilities. The NASA/NSF panel concluded that the United States has lost its leading position in many critical satellite communications technologies. Although U.S. industry retains a leading position in today's marketplace for satellite communications systems and services, this position is largely founded on technologies and capabilities developed in the 1960s and 1970s. Because the United States is losing ground with respect to a wide range of technologies and systems that will be key to future communications markets, the market share of the U.S. satellite communications industry is at risk.

  6. Introducing Multisensor Satellite Radiance-Based Evaluation for Regional Earth System Modeling

    NASA Technical Reports Server (NTRS)

    Matsui, T.; Santanello, J.; Shi, J. J.; Tao, W.-K.; Wu, D.; Peters-Lidard, C.; Kemp, E.; Chin, M.; Starr, D.; Sekiguchi, M.; Aires, F.

    2014-01-01

    Earth System modeling has become more complex, and its evaluation using satellite data has also become more difficult due to model and data diversity. Therefore, the fundamental methodology of using satellite direct measurements with instrumental simulators should be addressed especially for modeling community members lacking a solid background of radiative transfer and scattering theory. This manuscript introduces principles of multisatellite, multisensor radiance-based evaluation methods for a fully coupled regional Earth System model: NASA-Unified Weather Research and Forecasting (NU-WRF) model. We use a NU-WRF case study simulation over West Africa as an example of evaluating aerosol-cloud-precipitation-land processes with various satellite observations. NU-WRF-simulated geophysical parameters are converted to the satellite-observable raw radiance and backscatter under nearly consistent physics assumptions via the multisensor satellite simulator, the Goddard Satellite Data Simulator Unit. We present varied examples of simple yet robust methods that characterize forecast errors and model physics biases through the spatial and statistical interpretation of various satellite raw signals: infrared brightness temperature (Tb) for surface skin temperature and cloud top temperature, microwave Tb for precipitation ice and surface flooding, and radar and lidar backscatter for aerosol-cloud profiling simultaneously. Because raw satellite signals integrate many sources of geophysical information, we demonstrate user-defined thresholds and a simple statistical process to facilitate evaluations, including the infrared-microwave-based cloud types and lidar/radar-based profile classifications.

  7. An analysis of satellite state vector observability using SST tracking data

    NASA Technical Reports Server (NTRS)

    Englar, T. S., Jr.; Hammond, C. L.

    1976-01-01

    Observability of satellite state vectors, using only SST tracking data was investigated by covariance analysis under a variety of satellite and station configurations. These results indicate very precarious observability in most short arc cases. The consequences of this are large variances on many state components, such as the downrange component of the relay satellite position. To illustrate the impact of observability problems, an example is given of two distinct satellite orbit pairs generating essentially the same data arc. The physical bases for unobservability are outlined and related to proposed TDRSS configurations. Results are relevant to any mission depending upon TDRSS to determine satellite state. The required mathematical analysis and the software used is described.

  8. Astrometry of the main satellites of Uranus: 18 years of observations

    E-print Network

    Camargo, J I B; Vieira-Martins, R; Assafin, M; Braga-Ribas, F; Dias-Oliveira, A; Benedetti-Rossi, G; Gomes-Júnior, A R; Andrei, A H; Neto, D N da Silva

    2015-01-01

    We determine accurate positions of the main satellites of Uranus: Miranda, Ariel, Umbriel, Titania, and Oberon. Positions of Uranus, as derived from those of these satellites, are also determined. The observational period spans from 1992 to 2011. All runs were made at the Pico dos Dias Observatory, Brazil. We used the software called Platform for Reduction of Astronomical Images Automatically (PRAIA) to minimise (digital coronography) the influence of the scattered light of Uranus on the astrometric measurements and to determine accurate positions of the main satellites. The positions of Uranus were then indirectly determined by computing the mean differences between the observed and ephemeris positions of these satellites. A series of numerical filters was applied to filter out spurious data. These filters are mostly based on the comparison between the positions of Oberon with those of the other satellites and on the offsets as given by the differences between the observed and ephemeris positions of all sate...

  9. The National Polar-orbiting Operational Environmental Satellite System

    NASA Astrophysics Data System (ADS)

    Bloom, H.

    The tri-agency Integrated Program Office (IPO) is responsible for managing the development of the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS will replace the current military and civilian operational polar-orbiting ``weather'' satellites. The Northrop Grumman Space Technology - Raytheon team was competitively selected in 2002 as the Acquisition and Operations contractor team to develop, integrate, deploy, and operate NPOESS satellites to meet the tri-agency user requirements for NPOESS over the 10-year (2009-2018) operational life of the program. Beginning in 2009, NPOESS spacecraft will be launched into three orbital planes to provide significantly improved operational capabilities and benefits to satisfy critical civil and national security requirements for space-based, remotely sensed environmental data. With the development of NPOESS, we are evolving operational ``weather'' satellites into integrated environmental observing systems by expanding our capabilities to observe, assess, and predict the total Earth system - atmosphere, ocean, land, and the space environment. In recent years, the operational weather forecasting and climate science communities have levied more rigorous requirements on space-based observations of the Earth's system that have significantly increased demands on performance of the instruments, spacecraft, and ground systems required to deliver NPOESS data, products, and information to end users. The ``end-to-end'' system consists of: the spacecraft; instruments and sensors on the spacecraft; launch support capabilities; the command, control, communications, and data routing infrastructure; and data processing hardware and software. NPOESS will observe significantly more phenomena simultaneously from space than its operational predecessors. NPOESS is expected to deliver large volumes of more accurate measurements at higher spatial (horizontal and vertical) and temporal resolution at much higher data rates and with more frequent space-to-ground data communications than are currently in use. When NPOESS reaches full operational capability in 2013, spacecraft in all three orbital planes will provide global coverage with a data refresh rate of approximately four hours for most observations. User demands for more real-time data from NPOESS are driving the space and ground-based architectures for data routing and retrieval that will dramatically shorten data latency. To meet user-validated requirements for 55 geophysical parameters, NPOESS will deliver global data to four U.S. centers for processing and distribution to end users. Global data will be down-linked to 15 globally-distributed, low-cost, unmanned ground stations that will be tied to these four processing centers via commercial fiber-optic networks. This innovative ground system will deliver 75% of the global (daily average) within 15 minutes and 95% of the data (daily average) within 26 minutes from the time of on-orbit collection. NPOESS spacecraft will also simultaneously broadcast two types of real-time data to suitably equipped ground stations. Early flight-testing of instruments will reduce development risk and demonstrate and validate global imaging and sounding instruments, algorithms, and pre-operational ground systems prior to the first NPOESS flight in 2009. Four NPOESS sensors are scheduled to fly on the joint National Aeronautics and Space Administration (NASA)/IPO NPOESS Preparatory Project (NPP) mission in 2006. Early system-level integration and testing will provide ``lessons learned'' and allow for any required modifications in time to support readiness for the first NPOESS launch in 2009. NPP will demonstrate the utility of improved imaging and radiometric data in short-term weather ``nowcasting'' and forecasting and in other oceanic and terrestrial applications, such as harmful algal blooms, volcanic ash, and wildfire detection. NPP will help ensure continuity of important climate-quality measurements during the transition from NASA's Earth Observing System Terra and Aqua research mis

  10. Reusable Reentry Satellite (RRS) system design study

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Reusable Reentry Satellite (RRS) is intended to provide investigators in several biological disciplines with a relatively inexpensive method to access space for up to 60 days with eventual recovery on Earth. The RRS will permit totally intact, relatively soft, recovery of the vehicle, system refurbishment, and reflight with new and varied payloads. The RRS is to be capable of three reflights per year over a 10-year program lifetime. The RRS vehicle will have a large and readily accessible volume near the vehicle center of gravity for the Payload Module (PM) containing the experiment hardware. The vehicle is configured to permit the experimenter late access to the PM prior to launch and rapid access following recovery. The RRS will operate in one of two modes: (1) as a free-flying spacecraft in orbit, and will be allowed to drift in attitude to provide an acceleration environment of less than 10(exp -5) g. the acceleration environment during orbital trim maneuvers will be less than 10(exp -3) g; and (2) as an artificial gravity system which spins at controlled rates to provide an artificial gravity of up to 1.5 Earth g. The RRS system will be designed to be rugged, easily maintained, and economically refurbishable for the next flight. Some systems may be designed to be replaced rather than refurbished, if cost effective and capable of meeting the specified turnaround time. The minimum time between recovery and reflight will be approximately 60 days. The PMs will be designed to be relatively autonomous, with experiments that require few commands and limited telemetry. Mass data storage will be accommodated in the PM. The hardware development and implementation phase is currently expected to start in 1991 with a first launch in late 1993.

  11. A simple time dissemination system via the TV satellite.

    NASA Astrophysics Data System (ADS)

    Song, Jinan

    1996-06-01

    A simple time dissemination system via the TV satellite is proposed. Just adding a set of ranging device to the TV broadcasting system, then it will have the timing function with a accuracy of better than 15 ?s in China.

  12. Disaster warning system study summary. [cost estimates using NOAA satellites

    NASA Technical Reports Server (NTRS)

    Leroy, B. F.; Maloy, J. E.; Braley, R. C.; Provencher, C. E.; Schumaker, H. A.; Valgora, M. E.

    1977-01-01

    A conceptual satellite system to replace or complement NOAA's data collection, internal communications, and public information dissemination systems for the mid-1980's was defined. Program cost and cost sensitivity to variations in communications functions are analyzed.

  13. Multi-stakeholder Interactive Simulation for Federated Satellite Systems

    E-print Network

    Grogan, Paul Thomas

    Federated satellite systems (FSS) are a new class of space-based systems which emphasize a distributed architecture. New information exchanging functions among FSS members enable data transportation, storage, and processing ...

  14. Automated tracking for advanced satellite laser ranging systems

    NASA Astrophysics Data System (ADS)

    McGarry, Jan F.; Degnan, John J.; Titterton, Paul J., Sr.; Sweeney, Harold E.; Conklin, Brion P.; Dunn, Peter J.

    1996-06-01

    NASA's Satellite Laser Ranging Network was originally developed during the 1970's to track satellites carrying corner cube reflectors. Today eight NASA systems, achieving millimeter ranging precision, are part of a global network of more than 40 stations that track 17 international satellites. To meet the tracking demands of a steadily growing satellite constellation within existing resources, NASA is embarking on a major automation program. While manpower on the current systems will be reduced to a single operator, the fully automated SLR2000 system is being designed to operate for months without human intervention. Because SLR2000 must be eyesafe and operate in daylight, tracking is often performed in a low probability of detection and high noise environment. The goal is to automatically select the satellite, setup the tracking and ranging hardware, verify acquisition, and close the tracking loop to optimize data yield. TO accomplish the autotracking tasks, we are investigating (1) improved satellite force models, (2) more frequent updates of orbital ephemerides, (3) lunar laser ranging data processing techniques to distinguish satellite returns from noise, and (4) angular detection and search techniques to acquire the satellite. A Monte Carlo simulator has been developed to allow optimization of the autotracking algorithms by modeling the relevant system errors and then checking performance against system truth. A combination of simulator and preliminary field results will be presented.

  15. Ephemerides of the major Neptunian satellites determined from earth-based astrometric and Voyager imaging observations

    NASA Technical Reports Server (NTRS)

    Jacobson, R. A.; Lewis, G. D.; Owen, W. M.; Riedel, J. E.; Roth, D. C.; Synnott, S. P.; Taylor, A. H.

    1990-01-01

    The Voyager project used Neptunian satellite ephemerides to support both navigation and acquisition of scientific data. The development of postencounter ephemerides for the satellites Triton, Nereid, and 1989N1 is discussed. Primary results are the final set of model parameters which generate orbits that best fit both the earth-based satellite observations and data acquired by Voyager. The ephemerides are compared with those generated preencounter, and the accuracy of the final ephemerides is assessed. Mean orbital elements are also provided as a geometrical representation for the satellite orbits.

  16. Astrometric observations of Saturn's satellites from McDonald Observatory, 1972. [using reference stars

    NASA Technical Reports Server (NTRS)

    Abbot, R. I.; Mulholland, J. D.; Shelus, P. J.

    1974-01-01

    Observations of Saturn's satellites were reduced by means of secondary reference stars obtained by reduction of Palomar Sky Survey (PSS) plates. This involved the use of 39 SAO stars and plate overlap technique to determine the coordinates of 59 fainter stars in the satellite field. Fourteen plate constants were determined for each of the two PSS plates. Comparison of two plate measurement and reduction techniques on the satellite measurements demonstrate the existence of a serious background gradient effect and the utility of microdensitometry to eliminate this error source in positional determinations of close satellites.

  17. Synergy of Satellite-Surface Observations for Studying the Properties of Absorbing Aerosols in Asia

    NASA Technical Reports Server (NTRS)

    Tsay, Si-Chee

    2010-01-01

    Through interaction with clouds and alteration of the Earth's radiation budget, atmospheric aerosols significantly influence our weather and climate. Monsoon rainfalls, for example, sustain the livelihood of more than half of the world's population. Thus, understanding the mechanism that drives the water cycle and freshwater distribution is high-lighted as one of the major near-term goals in NASA's Earth Science Enterprise Strategy. Every cloud droplet/ice-crystal that serves as an essential element in portraying water cycle and distributing freshwater contains atmospheric aerosols at its core. In addition, the spatial and temporal variability of atmospheric aerosol properties is complex due to their dynamic nature. In fact, the predictability of the tropical climate system is much reduced during the boreal spring, which is associated with the peak season of biomass burning activities and regional/long-range transport of dust aerosols. Therefore, to accurately assess the impact of absorbing aerosols on regional-to-global climate requires not only modeling efforts but also continuous observations from satellites, aircraft, networks of ground-based instruments and dedicated field experiments. Since 1997 NASA has been successfully launching a series of satellites the Earth Observing System - to intensively study, and gain a better understanding of, the Earth as an integrated system. Through participation in many satellite remote-sensing/retrieval and validation projects over the years, we have gradually developed and refined the SMART (Surface-sensing Measurements for Atmospheric Radiative Transfer) and COMMIT (Chemical, Optical & Microphysical Measurements of In-situ Troposphere) mobile observatories, a suite of surface remote sensing and in-situ instruments that proved to be vital in providing high temporal measurements, which complement the satellite observations. In this talk, we will present SMART-COMMIT which has played key roles, serving as network or supersite, in major international research projects such as the Joint Aerosol Monsoon Experiment (JAM EX), a core element of the Asian Monsoon Years (AMY, 2008-2012). SMART-COMMIT deployments during 2008 AMY/JAMEX were conducted in northwestern China to characterize the properties of dust-laden aerosols and in the vicinity of Beijing for mega-city aerosols. In 2009, SMART-COMMIT also participated in the JAMEX/RAJO-MEGHA (Radiation, Aerosol Joint Observations-Monsoon Experiment in the Gangetic-Himalayan Area; Sanskrit for Dust-Cloud) to study the aerosol properties, solar absorption and the associated atmospheric warming, and the climatic impact of elevated aerosols during the pre-monsoon season in South Asia. We will show results from these field experiments, as well as discuss a new initiative of 7-SEAS (7 South East Asian Studies) to study the interaction of anthropogenic aerosols with regional meteorology, particularly with clouds.

  18. Validation of satellite observed thermal emission with in-situ measurements over an urban surface

    E-print Network

    Wunderle, Stefan

    and validations of thermal satellite imagery are conducted in rural, mostly homogeneous areas (Sobrino et alValidation of satellite observed thermal emission with in-situ measurements over an urban surface daytime imagery at about the same time of MODIS overpass is available. This enables the validation

  19. Recent glacier changes in the Alps observed by satellite: Consequences for future monitoring strategies

    E-print Network

    Kääb, Andreas

    Recent glacier changes in the Alps observed by satellite: Consequences for future monitoring satellite-derived Swiss glacier inventory revealed that mean glacier area loss per decade from 1985 to 1998 display much evidence that down- wasting (i.e. stationary thinning) has become a major source of glacier

  20. Satellite observations of chlorophyll, phytoplankton biomass, and Ekman pumping in nonlinear mesoscale eddies

    E-print Network

    Kurapov, Alexander

    Satellite observations of chlorophyll, phytoplankton biomass, and Ekman pumping in nonlinear of chlorophyll-a, enhanced primary production and phytoplankton communities generally associated with nutrient-replete environments. From analysis of 9 years of concurrent satellite measurements of sea surface height, chlorophyll

  1. Observational Datasets We use two different satellite soil moisture datasets, one derived from the Advanced Microwave

    E-print Network

    Guichard, Francoise

    Observational Datasets We use two different satellite soil moisture datasets, one derived from of the datasets. Whilst the AMSRE soil moisture product is gridded at 0.25°, the footprint of the sensor different precipitation datasets which use a combination of satellite data and, in some cases, surface

  2. Spaceborne observations of a changing Earth - Contribution from ESÁ s operating and approved satellite missions.

    NASA Astrophysics Data System (ADS)

    Johannessen, J. A.

    2009-04-01

    The overall vision for ESÁs Earth Observation activities is to play a central role in developing the global capability to understand planet Earth, predict changes, and mitigate negative effects of global change on its populations. Since Earth observation from space first became possible more than forty years ago, it has become central to monitoring and understanding how the dynamics of the Earth System work. The greatest progress has been in meteorology, where space-based observations have become indispensable, but it is now also progressively penetrating many of the fields making up Earth sciences. Exploiting Earth observation from space presents major multidisciplinary challenges to the researches working in the Earth sciences, to the technologists who build the state-of-the-art sensors, and to the scientists interpreting measurements made of processes occurring on or within the Earth's surface and in its atmosphere. The scientific community has shown considerable imagination in rising to these challenges, and in exploiting the latest technological developments to measure from space the complex processes and interactions that occur in the Earth System. In parallel, there has been significant progress in developing computer models that represent the many processes that make up the Earth System, and the interactions and feedback between them. Success in developing this holistic view is inextricably linked to the data provided by Earth Observation systems. Satellites provide the fundamental, consistent, regular and global measurements needed to drive, parameterise, test and improve those Earth System models. These developments, together with changes in society's awareness of the need for information on a changing world, have repetitively supported the decisions on how ESA can best focus its resources, and those of the European community that it serves, in order to address critical issues in Earth System science. Moreover, it is a fact that many operational, managerial and regulatory activities (i.e. weather forecasting, deforestation, flooding, etc.) essential to the safe exploitation of global resources, conservation of sustainable ecosystems, and the compliance with numerous international treaties and conventions, depend absolutely on continuity of satellite missions to maximise socio-economic and environmental benefits. This presentation will highlight some of the multidisciplinary Earth science achievements and operational applications using ESA satellite missions. It will also address some of the key scientific challenges and need for operational monitoring services in the years to come. It capitalizes on the knowledge and awareness outlined in "The Changing Earth - New scientific challenges for ESÁs Living Planet Programme" issued in 2006 together with updated views and approved plans expressed during ESÁs Earth Sciences Advisory Committee (ESAC) meetings and agreed at the recent User Consultation meeting in January 2009.

  3. A practical system for regional mobile satellite services

    NASA Technical Reports Server (NTRS)

    Glein, Randall; Leverson, Denis; Olmstead, Dean

    1993-01-01

    The Regional Mobile Satellite (MSAT) concept proposes a worldwide, interconnected mobile satellite service (MSS) network in which MSAT-type satellites provide the space segment services to separate regions (i.e., one or a few countries). Using this concept, mobile communications users across entire continents can now be served by a handful of regionally controlled satellites in geostationary earth orbit (GEO). All requirements, including hand-held telephone capabilities, can be cost-effectively provided using proven technologies. While other concepts of regional or global mobile communications continue to be explored, the Hughes Regional MSAT system demonstrates the near-term viability of the GEO approach.

  4. Some 'lost' observations from McDonald Observatory of the faint outer satellites of Jupiter

    NASA Astrophysics Data System (ADS)

    Shelus, Peter J.; Whipple, Arthur L.; Benedict, G. F.; Mulholland, J. D.

    1992-08-01

    Attention is given to a number of photographic exposures of the faint outer satellites of Jupiter that were taken with the 2.1-m Otto Struve reflector at McDonald Observatory in the late 1970s and early 1980s. The plates, together with the relevant observing logs, were measured and reduced. Observed positions and corrected and deleted observations of Jovian satellites are presented.

  5. The investigation of tethered satellite system dynamics

    NASA Technical Reports Server (NTRS)

    Lorenzini, E.

    1985-01-01

    The tether control law to retrieve the satellite was modified in order to have a smooth retrieval trajectory of the satellite that minimizes the thruster activation. The satellite thrusters were added to the rotational dynamics computer code and a preliminary control logic was implemented to simulate them during the retrieval maneuver. The high resolution computer code for modelling the three dimensional dynamics of untensioned tether, SLACK3, was made fully operative and a set of computer simulations of possible tether breakages was run. The distribution of the electric field around an electrodynamic tether in vacuo severed at some length from the shuttle was computed with a three dimensional electrodynamic computer code.

  6. Formation of multiple-satellite systems from circumplanetary particle disks

    NASA Astrophysics Data System (ADS)

    Hyodo, Ryuki; Ohtsuki, K.; Takeda, T.

    2013-10-01

    In the solar system, most of the planets have satellite systems around them. In systems with a single satellite such as Earth-Moon system, satellite mass is relatively high compared to the host planet’s mass. On the other hand, giant planets such as Jupiter, Saturn have multiple-satellite systems. Generally, their inner major satellites called regular satellites exist outside their Roche limit with relatively small mass ratio to the host planet. Those inner satellites are on nearly circular prograde orbits with low inclination. Formation of large regular satellites of Jupiter and Saturn has been explained by accretion in a circumplanetary gas disk (Canup & Ward 2009). On the other hand, it has been recently shown that regular satellites of Saturn, Uranus and Neptune can be formed from a circumplanetary particle disks within the Roche limit (Crida & Charnoz 2012). Formation of satellites from those particle disks was first studied in the context of lunar formation (Ida, S., et al., 1997). Initially, particles are distributed within the Roche limit and their accretion is prohibited. Then, the disk spreads with time. As the disk spreads and the disk materials diffuse beyond the Roche limit, the materials start to form gravitationally bound aggregates. In the case of relatively massive disk, a large single satellite is its outcome (Ida, S., et al., 1997). However, if the initial disk is less massive, the viscosity of the disk is low and the time scale of disk diffusion is much longer. These aspects expect to lead to the different outcomes. Crida and Charnoz (2012) developed an analytic model for the formation of multiple satellites from a circumplanetary particle disk, with the assumption that the mass flow through the Roche limit is constant. Their model successfully explains the characteristics of the masses and orbits in the satellite systems of Saturn, Uranus and Neptune. However, the details of the evolution of less massive disk are still unclear. In the present work, we perform N-body simulations in order to see the evolution of less massive circumplanetary particle disks, and show that another satellite is secondly formed from a residual disk after the formation of the first satellite.

  7. Satellite power system (SPS) brightness due to reflected sunlight

    SciTech Connect

    1980-10-01

    The development and operation of a Satellite Power System would place very large structures in orbit around earth for several decades. Sunlight reflected off such structures, particularly specular components from large flat areas, is expected to create ground illumination that will attract observers. In order to assure that this illumination does not exceed the irradiance tolerances of the eye, reflections from these satellites must be carefully controlled by vehicle orientation and surface specifications. The solar power satellite (SPS) at geosynchronous earth orbit (GEO) has 55 km/sup 2/ of glass covered solar cells that are oriented normal to the sun, as well as a 1 km/sup 2/ microwave antenna. Transportation of construction materials from low earth orbit (LEO) to GEO requires 23 Orbit Transfer Vehicles (OTVs) that have 1.6 km/sup 2/ solar panels oriented normal to the sun during their 6 month transits. The Staging Base (SB) at LEO, that accommodates OTV fabrication and cargo transfer, consists of 0.5 km arms protruding from a .44 km/sup 2/ open grid aligned with its orbit plane. Diffuse reflections would make the SB/OTVs readily discernible in the daytime and the OTVs and SPSs observable all night (except during eclipse). Sporadic specular glints would appear on the ground from the OTVs and SPSs near the midnight meridian, from the solar panel surfaces of OTVs during LEO fabrication around midday, and from OTVs near LEO at dawn and dusk. The ground level irradiance has been evaluated for several unusually bright configurations using the present system design. Procedures and results are presented and discussed.

  8. CEOS WGISS Integrated Catalog, A Catalog for Earth Observation Satellite Data

    NASA Astrophysics Data System (ADS)

    Enloe, Y.; Yapur, M.

    2011-12-01

    The Committee on Earth Observation Satellites (CEOS) was formed in 1984 to coordinate the world's civil space-borne observations of the Earth. More recently, CEOS and its member agencies have committed to provide the implementation of the space-based component of the Group on Earth Observation (GEO) Global Earth Observation System of Systems (GEOSS) Common Infrastructure (GCI). In the case of CEOS, there are a number of challenges in directly connecting the components and services of its member agencies to the GCI. In many cases, the existing catalog systems of the member agencies do not support the OGC Catalog Service for the Web (CSW) that has been selected as the standard for the GCI. Another challenge is related to the fact that collections of satellite data products are extremely large and constantly growing with millions of individual products. Harvesting the associated metadata into the clearinghouse of the GCI is not a practical alternative. In addition, the collection/granule hierarchy and unique spatial/temporal characteristics of satellite data and the user registration and asynchronous access requirements of the agency systems pose additional challenges. The CEOS approach has been to design and implement a CEOS WGISS Integrated Catalog (CWIC) that will serve as a community catalog of the products and services that are offered through its member's systems. CWIC will be based on a distributed search architecture and serve as a gateway between the GEO portal or community portals and clients and the CEOS agency systems. CWIC will receive standard search queries from these portals or clients all using the GEO supported catalog standard, the OGC CSW 2.0.2 and the WGISS Search Criteria for granule search and translate them into the native protocols of the underlying catalogs. Likewise, the result sets from the CEOS agency catalogs will be converted to the form that will be compatible with the portals and clients. The CWIC data provider partners include NOAA, NASA, USGS, INPE (Brazil), and two Chinese data centers coordinated by the Chinese Academy of Science have joined the engineering team and their systems are accessible via CWIC. In addition, multiple other CEOS agencies are or plan to be members of the teams developing community portals and clients that will access CWIC. Recently, NASA initiated development of a prototype client to access CWIC. The ultimate goal of the CEOS WGISS effort is to make the satellite data and services of its member agencies more accessible and useful to the broad set of GEO research programs and applications and this is most effectively approached by harmonization within the satellite community. This kind of community-based development with the harmonization occurring first within the community and then being offered to the broader GEO systems fits the original GEO vision of becoming "a system of systems", clearly representing a contribution towards achieving full interoperability in a standards-based manner.

  9. Earth observing system implementation

    NASA Technical Reports Server (NTRS)

    Donohoe, M. J.; Walton, B. A.; Vane, D.

    1985-01-01

    The Earth Observing System (EOS) is a planned major earth science program initiative using the Polar Platforms of the Space Station. The Polar Platform resource capabilities will allow a multi-disciplinary, long term mission life approach to future earth science measurements. The EOS will be the subject of an Announcement of Opportunity (AO) in 1986. The EOS concept and the planned implementation approach is outlined.

  10. An observation of a mutual event between two satellites of Uranus

    E-print Network

    M. G. Hidas; A. A. Christou; T. M. Brown

    2007-11-13

    We present observations of the occultation of Umbriel by Oberon on 4 May, 2007. We believe this is the first observed mutual event between satellites of Uranus. Fitting a simple geometric model to the lightcurve, we measure the mid-event time with a precision of 4 seconds. We assume previously measured values for the albedos of the two satellites (Karkoschka 2001), and measure the impact parameter to be 500 +/- 80 km. These measurements are more precise than estimates based on current ephemerides for these satellites. Therefore observations of additional mutual events during the 2007-2008 Uranian equinox will provide improved estimates of their orbital and physical parameters.

  11. 78 FR 31576 - Enforcement Proceeding; Certain Two-Way Global Satellite Communication Devices, System and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-24

    ...Proceeding; Certain Two-Way Global Satellite Communication Devices, System and Components...importation of certain two-way global satellite communication devices, system and components...after importation any two-way global satellite communication devices, system,...

  12. Navstar GPS and GLONASS. Global satellite navigation systems

    NASA Astrophysics Data System (ADS)

    Daly, P.

    Both the Navstar GPS and GLONASS satellite navigation systems developed respectively by the U.S.A. and the Soviet Union are now planned to become operational by 1995. Both systems are capable of providing the civil community with high-precision position-fixes and/or timing references on a continuous, world-wide basis. Already both systems have several satellites in orbit in order for pre-operational testing to be conducted. The paper discusses (i) the widely-differing launch histories of both systems, (ii) developments in planned use of orbits, (iii) the deliberate degradation of accuracy by the use of selective availability, (iv) progress in plans to provide a joint Navstar GPS/GLONASS civil satellite navigation system possibly integrated with other satellite ranging systems and (v) current status of both systems.

  13. Antenna dimensions of synthetic aperture radar systems on satellites

    NASA Technical Reports Server (NTRS)

    Richter, K. R.

    1973-01-01

    Design of a synthetic aperture radar (SAR) for a satellite must take into account the limitation in weight and dimensions of the antenna. The lower limits of the antenna area are derived from the conditions of unambiguity of the SAR system. This result is applied to estimate the antenna requirements for SARs on satellites in circular orbits of various altitudes around Earth and Venus.

  14. The Globalstar satellite cellular communication system design and status

    NASA Astrophysics Data System (ADS)

    Dietrich, Fred J.

    1998-01-01

    The Globalstar cellular communication satellite system is described, including its use of Code Division Multiple Access (CDMA) as the basic modulation scheme. Use of diversity for signal quality, as well as power control, is described. Complex phased arrays on the satellite are also described.

  15. Passive synthesis of the antenna aperture for satellite systems

    NASA Astrophysics Data System (ADS)

    Shumskii, P. O.; Meshcheryakov, A. A.; Sharygin, G. S.

    2012-08-01

    The possibility of passive synthesis of the antenna aperture for satellite systems of monitoring ground-based radio radiation sources is discussed. Experimental data on the inverse passive synthesis on the Space-Earth paths are presented for reception of GPS navigation satellite radiation. The data confirm the possibility of developing the passive synthesized aperture radar and interference phase signal processing.

  16. Satellite communications systems and technology. Volume 2; Site Reports

    NASA Technical Reports Server (NTRS)

    Edelson, Burton I.; Pelton, Joseph N.; Bostian, Carles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Helm, Neil R.; Jennings, Raymond D.; Kwan, Robert K.; Mahle, Christoph E.; Miller, Edward F.; Riley, Lance

    1993-01-01

    Volume 2 of the final report of the NASA/NSF Panel on Satellite Communications Systems and Technology is presented. It consists of the site reports from the panel's visits to satellite communications facilities and laboratories in Europe, Japan, and Russia.

  17. Monitoring Global Precipitation Using Satellite Observations: Status and Future

    NASA Technical Reports Server (NTRS)

    Adler, Robert F.; Huffman, George; Curtis, Scott; Bolvin, David; Nelkin, Eric

    2002-01-01

    The current status of monitoring global precipitation amounts and patterns is described using data sets from the Global Precipitation Climatology Project (GPCP) of the World Climate Research Program (WCRP) and from recent research satellites, especially the Tropical Rainfall Measuring Mission (TRMM). The GPCP monthly (and pentad) data set is a 23-year, globally complete precipitation analysis that is used to explore global and regional variations and trends. The data set is a blend of data mainly from low-orbit microwave satellites and geosynchronous infrared satellites, with additional input from satellite sounder data, Outgoing Longwave Radiation (OLR) data and raingauges. The monthly GPCP data set shows no significant global trend in precipitation over the twenty years, unlike the positive trend in global surface temperatures over the past century. Regional trends are also analyzed. A trend pattern that is a combination of both El Nino and La Nina precipitation features is evident in the 23-year data set. This pattern is related to an increase with time in the number of combined months of El Nino and La Nina during the 23-year period. This apparent trend may be a short-term variation, but also might be related to the increase with time of extreme precipitation events reported elsewhere. Patterns of precipitation variation related to ENSO and other phenomena are shown with clear signals extending from the Tropics into middle and high latitudes of both hemispheres. Also shown, as an example of higher time resolution data is the GPCP daily analysis, which is available for the last six years. A second focus of the talk is on TRMM precipitation data and how these newer data sets incorporating information from the first space-borne meteorological radar compare with the established GPCP data sets.

  18. Multiple-satellite observation of the high-latitude auroral activity on January 11, 1983

    SciTech Connect

    Gorney, D.J.; Evans, D.S.; Gussenhoven, M.S.; Mizera, P.F.

    1986-01-01

    Unusual high-latitude auroral activity occurred on January 11, 1983, during a period of persistent interplanetary magnetic field Bz > 0, By > 0, and Bx > 0. This activity, which lasted from 0600 to 2100 UT, was characterized by numerous high-latitude sun-aligned arcs and a diffuse oval. Near 1500 UT, a single broad (250 km) sun-aligned arc was observed by the optical line scan system on Defense Meteorological Satellite Program (DMSP) F6. The arc was continguous with the dawn auroral oval and extended across the northern polar cap, similar to previously reported theta aurora configurations. The fortunate orbital locations of the DMSP F6, NOAA 7, and NOAA 6 satellites allow a detailed analysis of the precipitating-particle populations responsible for both the sun-aligned arc and oval auroras. Specifically, NOAA 7 and DMSP F6 cross the broad sun-aligned arc almost simultaneously in the northern hemisphere, with NOAA 7 crossing the arc 1500 km farther toward the dayside. During the arc crossing, NOAA 7 observes electron fluxes, temperatures, and accelerations similar to those observed by DMSP F6 but observes ion fluxes diminished by a factor of 50 in comparison with DMSP. Almost simultaneously, NOAA 6 crosses the southern polar cap and observes flux levels in an apparent high-latitude arc comparable to those observed by DMSP. The results are consistent with, but supplementary to, previous observations of high-latitude auroral observations and thus place meaningful constraints on emerging theoretical concepts of this phenomenon.

  19. Malvinas Current variability as observed by satellite altimetry data

    NASA Astrophysics Data System (ADS)

    Saraceno, Martin; Artana, Camila; Bodichon, Renaud; Provost, Christine

    The Malvinas Current (MC) is the northernmost extension of the Antarctic Circumpolar Current that carries cold and nutrient-rich waters. The MC is thought to be a major source of nutrients to the SW South Atlantic. The interaction of the MC with the sloping bottom is presumably responsible for sustaining upwelling along the shelf-break. Numerical and analytical models indicate that the upwelling intensity and mean transport along the Patagonian continental shelf is modulated by the MC transport. Apart from its regional influence, the MC contributes to regulate the climate since it helps the exchange of heat and salt as is a crucial component of the Meridional Overturning Circulation. Satellite altimetry data in conjunction with in-situ data allowed monitoring the transport of the MC at 41ºS. A CNES founded program will repeat those measures and will measure at the same time currents over the continental shelf under a satellite altimetry track. First deployment of instruments will occur in November 2014. In this work we use satellite altimetry data to explore the relationship between the MC and continental shelf transports and the correspondence between the variability of the MC and the mesoscale activity in the SW South Atlantic. Results suggest that (i) the large decreases of the MC transport are associated to eddies that interact with the MC and (ii) the first mode associated to the variability of the transport over the Patagonian continental shelf is significantly correlated to the first mode of variability of the MC transport.

  20. Radiative Transfer Simulations Using Mesoscale Cloud Model Outputs: Comparisons with Passive Microwave and Infrared Satellite Observations for Midlatitudes

    E-print Network

    Chaboureau, Jean-Pierre

    Radiative Transfer Simulations Using Mesoscale Cloud Model Outputs: Comparisons with Passive Microwave and Infrared Satellite Observations for Midlatitudes INGO MEIROLD-MAUTNER, CATHERINE PRIGENT Transmission at Microwave (ATM) radiative transfer model. Satellite-observed brightness temperatures (TBs) from

  1. Solar power satellite system definition study. Volume 3: Reference system description, phase 1

    NASA Technical Reports Server (NTRS)

    1979-01-01

    An analysis of the solar power satellite system is presented. The satellite solar energy conversion and microwave power transmission systems are discussed including the structure, power distribution, thermal control, and energy storage. Space construction and support systems are described including the work support facilities and construction equipment. An assessment of the space transportation system for the satellite and the ground receiving station is presented.

  2. Solar power satellite system definition study. Volume 2, phase 1: Systems analyses tradeoffs.

    NASA Technical Reports Server (NTRS)

    1979-01-01

    A systems definition study of the solar power satellite system is presented. The satellite solar energy conversion and microwave power transmission systems are discussed. Space construction and support systems are examined including a series construction and equipment characteristics analysis. Space transportation for the satellite and the ground receiving station are assessed.

  3. Evaluation of Long-Term Cloud-Resolving Model Simulations Using Satellite Radiance Observations and Multi-Frequency Satellite Simulators

    NASA Technical Reports Server (NTRS)

    Matsui, Toshihisa; Zeng, Xiping; Tao, Wei-Kuo; Masunaga, Hirohiko; Olson, William S.; Lang, Stephen

    2008-01-01

    This paper proposes a methodology known as the Tropical Rainfall Measuring Mission (TRMM) Triple-Sensor Three-step Evaluation Framework (T3EF) for the systematic evaluation of precipitating cloud types and microphysics in a cloud-resolving model (CRM). T3EF utilizes multi-frequency satellite simulators and novel statistics of multi-frequency radiance and backscattering signals observed from the TRMM satellite. Specifically, T3EF compares CRM and satellite observations in the form of combined probability distributions of precipitation radar (PR) reflectivity, polarization-corrected microwave brightness temperature (Tb), and infrared Tb to evaluate the candidate CRM. T3EF is used to evaluate the Goddard Cumulus Ensemble (GCE) model for cases involving the South China Sea Monsoon Experiment (SCSMEX) and Kwajalein Experiment (KWAJEX). This evaluation reveals that the GCE properly captures the satellite-measured frequencies of different precipitating cloud types in the SCSMEX case but underestimates the frequencies of deep convective and deep stratiform types in the KWAJEX case. Moreover, the GCE tends to simulate excessively large and abundant frozen condensates in deep convective clouds as inferred from the overestimated GCE-simulated radar reflectivities and microwave Tb depressions. Unveiling the detailed errors in the GCE s performance provides the best direction for model improvements.

  4. Earth Observation Convoy: Synergetic Observations with Satellites Flying in Formation with European Operational Missions - Possibilities for New Science

    NASA Astrophysics Data System (ADS)

    Regan, A.; Silvestrin, P.; Fernandez, D.; Leveque, N.; Eves, S.

    2012-04-01

    Over the next few years a number of new long-term operational Earth Observation (EO) satellites will be launched by Europe. These missions include the GMES (Global Monitoring for Environment and Security) Sentinel spacecraft and the EUMETSAT operated Metop satellite series. These missions will provide global, continuous and long-term European capability for systematic observation of a panoply of Earth system parameters. If additional cost-effective missions could be flown together with these operational missions then the possibilities for meeting new Earth science and application objectives could be far-reaching e.g. fulfilling observational gaps, multipoint measurement of Earth system phenomena, etc. Therefore, the European Space Agency (ESA) is funding three exploratory activities (known as the EO-Convoy studies). The aim of these studies is two fold: Firstly, to identify scientific and operational objectives and needs which would benefit from additional in-orbit support. Secondly, to identify and develop a number of cost-effective mission concepts that would meet these identified objectives and needs. Each EO Convoy study is dedicated to a specific theme: • Study 1: Ocean and Ice • Study 2: Land • Study 3: Atmosphere Each study is based on a comprehensive user needs analysis derived from Earth science analysis, applications and identification of novel data products. Based on this analysis a number of preliminary mission concepts are derived together with possible formation and constellation options. Up to three mission concepts per theme are then selected for detailed analysis including a roadmap for development. For the Ocean and Ice EO Convoy study the scientific analysis identified a number of areas where support measurements from additional satellites would prove valuable e.g. ocean topography and ocean currents, ocean colour, sea surface salinity, sea-ice drift and thickness, sea-ice melt on-set and duration, snow accumulation on ice sheets, freeze and thaw cycles, snow albedo and the measurement of snow microphysical properties. Based on this analysis over ten mission convoy concepts were identified and subsequently three concepts were selected for detailed analysis: • A passive C-band SAR to fly with Sentinel-1 • A laser altimeter to fly with Sentinel-3 • A Ku-band Scatterometer to fly with Metop SG. This paper will present the latest results of the Ocean and Ice EO-Convoy study which will include an overview of the user needs analysis and derived mission concepts (with an emphasis on the three selected concepts) and the resulting roadmaps for further research and development. For the Land EO Convoy the user needs analysis has identified a number of areas where support measurements from additional satellites would be useful e.g. carbon stocks and flux estimation at improved spatial scales, vegetation height estimation, surface albedo measurement, biomass characterisation, emissivity and land surface temperature measurement at high spatial resolution and improved fire products. The user needs consultation phase has now been completed and the consolidated results will be presented. A number of preliminary convoy concepts comprising additional satellites flying together with GMES Sentinels 1,2 and 3 have been identified based on this user needs analysis and will be presented. Examples include a high-resolution thermal infrared imager flying with either Sentinel-2 or 3 and additional SAR satellites flying with Sentinel-1.

  5. A new CM SAF Solar Surface Radiation Climate Data Set derived from Meteosat Satellite Observations

    NASA Astrophysics Data System (ADS)

    Trentmann, J.; Mueller, R. W.; Pfeifroth, U.; Träger-Chatterjee, C.; Cremer, R.

    2014-12-01

    The incoming surface solar radiation has been defined as an essential climate variable by GCOS. It is mandatory to monitor this part of the earth's energy balance, and thus gain insights on the state and variability of the climate system. In addition, data sets of the surface solar radiation have received increased attention over the recent years as an important source of information for the planning of solar energy applications. The EUMETSAT Satellite Application Facility on Climate Monitoring (CM SAF) is deriving surface solar radiation from geostationary and polar-orbiting satellite instruments. While CM SAF is focusing on the generation of high-quality long-term climate data records, also operationally data is provided in short time latency within 8 weeks. Here we present SARAH (Solar Surface Radiation Dataset - Heliosat), i.e. the new CM SAF Solar Surface Radiation data set based on Meteosat satellite observations. SARAH provides instantaneous, daily- and monthly-averaged data of the effective cloud albedo (CAL), the direct normalized solar radiation (DNI) and the solar irradiance (SIS) from 1983 to 2013 for the full view of the Meteosat satellite (i.e, Europe, Africa, parts of South America, and the Atlantic ocean). The data sets are generated with a high spatial resolution of 0.05 deg allowing for detailed regional studies, and are available in netcdf-format at no cost without restrictions at www.cmsaf.eu. We provide an overview of the data sets, including a validation against reference measurements from the BSRN and GEBA surface station networks.

  6. The Positions, Colors, and Photometric Variability of Pluto's Small Satellites from HST Observations 2005-2006

    E-print Network

    S. A. Stern; M. J. Mutchler; H. A. Weaver; A. J. Steffl

    2006-05-02

    Pluto's two small satellites, temporarily designated S/2005 P 1 and S/2005 P 2, were observed on four dates (15.1 and 18.1 May 2005, 15.7 February 2006, and 2.8 March 2006) using the Hubble Space Telescope's (HST) Advanced Camera for Surveys (ACS). Here we collect together the astrometric positions of these two satellites (henceforth P1 and P2), as well as a single color measurement for each satellite and initial constraints on their photometric variability obtained during these observations. We find that both satellites have essentially neutral (grey) reflectivities, like Charon. We also find that neither satellite exhibited strong photometric variation, which might suggest that P1 and P2 are toward the large end of their allowable size range, and therefore may have far lower reflectivities than Charon.

  7. Comparison of satellite-derived and in-situ observations of ice and snow surface temperatures over Greenland

    E-print Network

    Box, Jason E.

    Comparison of satellite-derived and in-situ observations of ice and snow surface temperatures over temperature in the data-sparse cryosphere is by satellite remote sensing. The uncertainties in satellite) records needed for climate studies. In this work we assess satellite-derived "clear-sky" LST products from

  8. Model Evaluation with Multi-wavelength Satellite Observations Using a Neural Network

    NASA Astrophysics Data System (ADS)

    Kolassa, Jana; Jimenez, Carlos; Aires, Filipe

    2013-04-01

    A methodology has been developed to evaluate fields of modelled parameters against a set of satellite observations. The method employs a Neural Network (NN) to construct a statistical model capturing the relationship between the satellite observations and the parameter from a land surface model, in this case the Soil Moisture (SM). This statistical model is then used to estimate the parameter of interest from the set of satellite observations. These estimates are compared to the modelled parameter in order to detect local deviations indicating a possible problem in the model or in the satellite observations. Several synthetic tests, during which an artificial error was added to the"true" soil moisture fields, showed that the methodology is able to correct the errors (Jimenez et al., submitted, 2012). This evaluation technique is very general and can be applied to any modelled parameter for which sensitive satellite observations are available. The use of NNs simplifies the evaluation of the model against satellite observations and is particularly well-suited to utilize the synergy from the observations at different wavelengths (Aires et al., 2005, 2012). In this study the proposed methodology has been applied to evaluate SM fields from a number of land surface models against a synergy of satellite observations from passive and active microwave, infrared and visible sensors. In an inter-comparison of the performance of several land surface models (ORCHIDEE (de Rosnay et al., 2002), HTESSEL (Balsamo et al., 2009), JULES (Best et al., 2011) ) it was found that the soil moisture fields from JULES, HTESSEL and ORCHIDEE are very consistent with the observations, but ORCHIDEE soil moisture shows larger local deviations close to some river basins (Kolassa et al., in press, 2012; Jimenez et al., submitted, 2012). Differences between all models and the observations could also be observed in the Eastern US and over mountainous regions, however, the errors here are more likely linked to the retrieved SM uncertainties. The proposed methodology can also be used to evaluate the quality of the model forcings: two soil moisture fields from ORCHIDEE using WATCH (Weedon et al., 2011) and ERA-interim (Balsamo et al., 2010) forcings were analysed. It was shown that the WATCH forcing data are more optimal, underlining the importance of forcing data for the accuracy of model predictions (Kolassa et al., in press, 2012). References Aires, F., Prigent, C., and Rossow, W.B. (2005), Sensitivity of satellite microwave and infrared observations to soil moisture at a global scale: 2. Global statistical relationships, J. Geophys. Res., 110, D11103, doi:10.1029/2004JD005094. Aires, F., O. Aznay, C. Prigent, M. Paul, F. Bernardo, Synergetic multi-wavelegnth remote sensing versus a posteriori combination of retrieved products: Application for the retrieval of atmospheric profiles using MetOp measurements, J. Geophys. Res., 2011 Balsamo, G., Viterbo, P., Beljaars, A., van den Hurk, B., Hirschi, M., Betts, A. and Scipa,l K. (2009) A Revised Hydrology for the ECMWF Model: Verification from Field Site to Terrestrial Water Storage and Impact in the Integrated Forecast System, J. Hydrol., 10, 623-643 Balsamo, G., Boussetta, S., Lopez, P., and Ferranti, L. (2010), Evaluation of ERA-Interim and ERA- Interim-GPCP-rescaled precipitation over the U.S.A., ERA-Report Series, 5, pp. 10. Best, M. J., M. Pryor, D. B. Clark, G. G. Rooney, R .L. H. Essery, C. B. Ménard, J. M. Edwards, M. A. Hendry, A. Porson, N. Gedney, L. M. Mercado, S. Sitch, E. Blyth, O. Boucher, P. M. Cox, C. S. B. Grimmond, and R. J. Harding (2011), The Joint UK Land Environment Simulator (JULES), model description - Part 1: Energy and water fluxes, Geosci. Model Dev., 4 Jimenez, C., Clark, D., Kolassa, J., Aires, F., Prigent, C., and Blyth, E. (2012), A joint analysis of modeled soil moisture fields and satellite observations (2012), J. Geophys. Res., Kolassa, J., Aires, F., Polcher, J., Prigent, C., and Pereira, J. (2012), Soil moisture Retrieval from Multi-instrument Observations: Inform

  9. Augmentation of a commercial satellite system for military communications

    NASA Astrophysics Data System (ADS)

    Butte, Eric G.; Thorburn, Michael

    2005-06-01

    Future U.S. MILSATCOM will rely on a complex satellite design to implement the TSAT satellite system that was developed on the Transformational Communication Architecture program. TSAT will deliver secured IP based, on-demand communication system to meet the needs of the military and the warfighter and will demand a very large satellite system, program, and an anticipated lengthy deployment time. An alternate system is proposed that can give IP based communications in a significantly shorter time frame. A constellation of commercial-like satellites, with transponded Ka-, Ku- and X-band, would nicely complement the MILSATCOM fleet. The services provided by these satellites would enable widespread communications services such as IP to the theatre, augmenting the DSCS, Wideband Gapfiller, and protected communications systems of MILSTAR and Advanced EHF. The capacity provided by the dedicated commercial satellites would help provide the capacity demanded by the warfighter as MILSATCOM transitions from today's technology to the TSAT system of tomorrow's Transformational Communications Architecture. This paper will discuss the satellite concept design and how it can augment the MILSATCOM fleet and show a more flexible approach of bandwidth management to support fixed and COTM terminals.

  10. Copernicus benefits the Norwegian Satellite Earth Observation Database for Marine and Polar Research

    NASA Astrophysics Data System (ADS)

    Korosov, Anton; Johannessen, Johnny

    2014-05-01

    The Norwegian Satellite Earth Observation Database for Marine and Polar Research (NORMAP) is developed for creating and maintaining a repository of Earth Observation data over the high latitude and Arctic regions to facilitate, stimulate and strengthen high quality and original multidisciplinary Earth System research, application, exploitation and education in marine, polar and climate sciences. As such it is complementing and supporting the Norwegian strategy for advancing these science disciplines in the high latitude and Arctic regions. In the international arena, NORMAP benefits and complements the EU GMES MyOcean project, and other previous GMES downstream services such as AQUAMAR, MONARCH-A, SIDARUS, etc. With the launch of the first Sentinel-1 mission NORMAP will be reinforced by the new data flow from the Copernicus Space Component. NORMAP is also acquiring data from a multitude of other satellites through the unified Copernicus system and will become one of the national thematic information services designed to benefit the environmental monitoring and support effective policy-making.

  11. A satellite system for land-mobile communications in Europe

    NASA Technical Reports Server (NTRS)

    Bartholome, P.; Rogard, R.

    1988-01-01

    There exists a great unsatisified demand for land mobile communications in Europe, particularly in sectors of business activity such as the road transport industry. This demand could best be satisfied by means of satellite-based private networks providing voice and data communications in a hub configuration. The potential market is estimated to encompass several hundred thousand road vehicles and the transmission capacity required would be several thousand channels. ESA is currently demonstrating the potential of satellite communications for this type of application, using a system called PRODAT. System studies are being performed with the aim of defining the architecture of a regional satellite system for Europe.

  12. Shuttle/tethered satellite system conceptual design study

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A closed-loop control system was added to the tether reel which improves control over the tethered satellite. In addition to increasing the stability of the tethered satellite along local vertical, this control system is used for deployment and retrieval of tethered satellites. This conceptual design study describes a tether system for suspending a science payload at an altitude of 120 km from space shuttle orbiter flying at an altitude of 200 km. In addition to the hardware conceptual designs, various aspects concerning Orbiter accommodations are discussed.

  13. Suitability of ANSI standards for quantifying communication satellite system performance

    NASA Technical Reports Server (NTRS)

    Cass, Robert D.

    1988-01-01

    A study on the application of American National Standards X3.102 and X3.141 to various classes of communication satellite systems from the simple analog bent-pipe to NASA's Advanced Communications Technology Satellite (ACTS) is discussed. These standards are proposed as means for quantifying the end-to-end communication system performance of communication satellite systems. An introductory overview of the two standards are given followed by a review of the characteristics, applications, and advantages of using X3.102 and X3.141 to quantify with a description of the application of these standards to ACTS.

  14. Connecting Satellite Observations with Water Cycle Variables Through Land Data Assimilation: Examples Using the NASA GEOS-5 LDAS

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf H.; De Lannoy, Gabrielle J. M.; Forman, Barton A.; Draper, Clara S.; Liu, Qing

    2013-01-01

    A land data assimilation system (LDAS) can merge satellite observations (or retrievals) of land surface hydrological conditions, including soil moisture, snow, and terrestrial water storage (TWS), into a numerical model of land surface processes. In theory, the output from such a system is superior to estimates based on the observations or the model alone, thereby enhancing our ability to understand, monitor, and predict key elements of the terrestrial water cycle. In practice, however, satellite observations do not correspond directly to the water cycle variables of interest. The present paper addresses various aspects of this seeming mismatch using examples drawn from recent research with the ensemble-based NASA GEOS-5 LDAS. These aspects include (1) the assimilation of coarse-scale observations into higher-resolution land surface models, (2) the partitioning of satellite observations (such as TWS retrievals) into their constituent water cycle components, (3) the forward modeling of microwave brightness temperatures over land for radiance-based soil moisture and snow assimilation, and (4) the selection of the most relevant types of observations for the analysis of a specific water cycle variable that is not observed (such as root zone soil moisture). The solution to these challenges involves the careful construction of an observation operator that maps from the land surface model variables of interest to the space of the assimilated observations.

  15. Satellite power system: Engineering and economic analysis summary

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A system engineering and economic analysis was conducted to establish typical reference baselines for the photovoltaic, solar thermal, and nuclear satellite power systems. Tentative conclusions indicate that feasibility and economic viability are characteristic of the Satellite Power System. Anticipated technology related to manufacturing, construction, and maintenance operations is described. Fuel consumption, environmental effects, and orbital transfer are investigated. Space shuttles, local space transportation, and the heavy lift launch vehicle required are also discussed.

  16. Temporal variation of the cloud top height over the tropical Pacific observed by geostationary satellites

    NASA Astrophysics Data System (ADS)

    Nishi, N.; Hamada, A.

    2012-12-01

    Stratiform clouds (nimbostratus and cirriform clouds) in the upper troposphere accompanied with cumulonimbus activity cover large part of the tropical region and largely affect the radiation and water vapor budgets there. Recently new satellites (CloudSat and CALIPSO) can give us the information of cloud height and cloud ice amount even over the open ocean. However, their coverage is limited just below the satellite paths; it is difficult to capture the whole shape and to trace the lifecycle of each cloud system by using just these datasets. We made, as a complementary product, a dataset of cloud top height and visible optical thickness with one-hour resolution over the wide region, by using infrared split-window data of the geostationary satellites (AGU fall meeting 2011) and released on the internet (http://database.rish.kyoto-u.ac.jp/arch/ctop/). We made lookup tables for estimating cloud top height only with geostationary infrared observations by comparing them with the direct cloud observation by CloudSat (Hamada and Nishi, 2010, JAMC). We picked out the same-time observations by MTSAT and CloudSat and regressed the cloud top height observation of CloudSat back onto 11?m brightness temperature (Tb) and the difference between the 11?m Tb and 12?m Tb. We will call our estimated cloud top height as "CTOP" below. The area of our coverage is 85E-155W (MTSAT2) and 80E-160W(MTSAT1R), and 20S-20N. The accuracy of the estimation with the IR split-window observation is the best in the upper tropospheric height range. We analyzed the formation and maintenance of the cloud systems whose top height is in the upper troposphere with our CTOP analysis, CloudSat 2B-GEOPROF, and GSMaP (Global Satellite Mapping of Precipitation) precipitation data. Most of the upper tropospheric stratiform clouds have their cloud top within 13-15 km range. The cloud top height decreases slowly when dissipating but still has high value to the end. However, we sometimes observe that a little lower cloud top height (6-10 km) is kept within one-two days. A typical example is observed on 5 January 2011 in a dissipating cloud system with 1000-km scale. This cluster located between 0-10N just west of the International Date Line and moved westward with keeping relatively lower cloud top (6-10 km) over one day. This top height is lower than the ubiquitous upper-tropospheric stratiform clouds but higher than the so-called 'congestus cloud' whose top height is around 0C. CloudSat data show the presence of convective rainfall. It suggests that this cloud system continuously kept making new anvil clouds in a little lower height than usual. We examined the seasonal variation of the distribution of cloud systems with a little lower cloud top height (6-11 km) during 2010-11. The number of such cloud systems is not constant with seasons but frequently increased in some specific seasons. Over the equatorial ocean region (east of 150E), they were frequently observed during the northern winter.

  17. NPP: Why Another Earth-Observing Satellite? - Duration: 2 minutes, 54 seconds.

    NASA Video Gallery

    NPP will soon be NASA's newest Earth-observing satellite. To showcase how NPP will be used for both understanding the health of our planet now -- as well as how things might change in the future --...

  18. Aerosol loading in the Southeastern United States: reconciling surface and satellite observations

    E-print Network

    Ford, B.

    We investigate the seasonality in aerosols over the Southeastern United States using observations from several satellite instruments (MODIS, MISR, CALIOP) and surface network sites (IMPROVE, SEARCH, AERONET). We find that ...

  19. Expert system for on-board satellite scheduling and control

    NASA Technical Reports Server (NTRS)

    Barry, John M.; Sary, Charisse

    1988-01-01

    An Expert System is described which Rockwell Satellite and Space Electronics Division (S&SED) is developing to dynamically schedule the allocation of on-board satellite resources and activities. This expert system is the Satellite Controller. The resources to be scheduled include power, propellant and recording tape. The activities controlled include scheduling satellite functions such as sensor checkout and operation. The scheduling of these resources and activities is presently a labor intensive and time consuming ground operations task. Developing a schedule requires extensive knowledge of the system and subsystems operations, operational constraints, and satellite design and configuration. This scheduling process requires highly trained experts anywhere from several hours to several weeks to accomplish. The process is done through brute force, that is examining cryptic mnemonic data off line to interpret the health and status of the satellite. Then schedules are formulated either as the result of practical operator experience or heuristics - that is rules of thumb. Orbital operations must become more productive in the future to reduce life cycle costs and decrease dependence on ground control. This reduction is required to increase autonomy and survivability of future systems. The design of future satellites require that the scheduling function be transferred from ground to on board systems.

  20. Satellite-aided land mobile communications system implementation considerations

    NASA Technical Reports Server (NTRS)

    Leroy, B. E.

    1982-01-01

    It was proposed that a satellite-based land mobile radio system could effectively extend the terrestrial cellular mobile system into rural and remote areas. The market, technical and economic feasibility for such a system is studied. Some of the aspects of implementing an operational mobile-satellite system are discussed. In particular, two key factors in implementation are examined: (1) bandwidth requirements; and (2) frequency sharing. Bandwidth requirements are derived based on the satellite antenna requirements, modulation characteristics and numbers of subscribers. Design trade-offs for the satellite system and potential implementation scenarios are identified. Frequency sharing is examined from a power flux density and modulation viewpoint. Previously announced in STAR as N82-25290