WorldWideScience

Sample records for satellite mediated station

  1. Blossom Point Satellite Tracking and Command Station

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: The Blossom Point Satellite Command and Tracking Facility (BP) provides engineering and operational support to several complex space systems for the Navy...

  2. POSITION ERROR IN STATION-KEEPING SATELLITE

    Science.gov (United States)

    of an error in satellite orientation and the sun being in a plane other than the equatorial plane may result in errors in position determination. The nature of the errors involved is described and their magnitudes estimated.

  3. 47 CFR 80.333 - Stations in the maritime mobile-satellite service.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Stations in the maritime mobile-satellite..., Alarm, Urgency and Safety Procedures § 80.333 Stations in the maritime mobile-satellite service. The...-satellite service....

  4. 78 FR 39200 - Federal Earth Stations-Non-Federal Fixed Satellite Service Space Stations; Spectrum for Non...

    Science.gov (United States)

    2013-07-01

    ...-11341; FCC 13-65] Federal Earth Stations--Non-Federal Fixed Satellite Service Space Stations; Spectrum... interference protection for Fixed-Satellite Service (FSS) and Mobile- Satellite Service (MSS) earth stations... and the important role it will play in our nation's economy and technological innovation now and in...

  5. 47 CFR 25.140 - Qualifications of fixed-satellite space station licensees.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Qualifications of fixed-satellite space station... CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses Space Stations § 25.140 Qualifications of fixed-satellite space station licensees. (a) New fixed-satellites shall comply with...

  6. 47 CFR 80.1185 - Supplemental eligibility for mobile-satellite stations.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Supplemental eligibility for mobile-satellite...-Satellite Stations § 80.1185 Supplemental eligibility for mobile-satellite stations. Stations in the maritime mobile-satellite service must meet the eligibility requirements contained in this section. (a)...

  7. Weather satellite picture receiving stations, APT digital scan converter

    Science.gov (United States)

    Vermillion, C. H.; Kamowski, J. C.

    1975-01-01

    The automatic picture transmission digital scan converter is used at ground stations to convert signals received from scanning radiometers to data compatible with ground equipment designed to receive signals from vidicons aboard operational meteorological satellites. Information necessary to understand the circuit theory, functional operation, general construction and calibration of the converter is provided. Brief and detailed descriptions of each of the individual circuits are included, accompanied by a schematic diagram contained at the end of each circuit description. Listings of integral parts and testing equipment required as well as an overall wiring diagram are included. This unit will enable the user to readily accept and process weather photographs from the operational meteorological satellites.

  8. 78 FR 14952 - Earth Stations Aboard Aircraft Communicating with Fixed-Satellite Service Geostationary-Orbit...

    Science.gov (United States)

    2013-03-08

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 2 Earth Stations Aboard Aircraft Communicating with Fixed-Satellite Service Geostationary-Orbit Space Stations AGENCY: Federal Communications Commission. ACTION: Proposed rule....

  9. Transportable IOT measurement station for direct-broadcast satellites

    Science.gov (United States)

    Ulbricht, Michael

    A transportable 11.7-12.5-GHz flux-density measurement facility for use in the in-orbit testing (IOT) of the FRG TV-Sat direct-broadcast satellites is described. Major components include a 1.2-m-diameter antenna, the fluxmeter, a radiometer to determine atmospheric attenuation, a weather station, and a control and data-processing computer; all of the components are mounted on a 5.10 x 2.35 x 2.70-m trailer. IOT performance parameters include gain/temperature ratio 15.9 dB/K, measurement range -97 to -117 dBW/sq m, measurement accuracy less than 0.5 dB rms, and measurement rate 250-650 msec. Photographs and a block diagram are provided.

  10. 47 CFR 25.215 - Technical requirements for space stations in the Direct Broadcast Satellite Service.

    Science.gov (United States)

    2010-10-01

    ... the Direct Broadcast Satellite Service. 25.215 Section 25.215 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.215 Technical requirements for space stations in the Direct Broadcast Satellite Service. In addition to §...

  11. Fault Detection and Isolation of Satellite Formations using a Ground Station Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal is for the development a fault detection and isolation (FDI) algorithm for a formation of satellites but processed at a ground station. The algorithm...

  12. Economic benefits of the Space Station to commercial communication satellite operators

    Science.gov (United States)

    Price, Kent M.; Dixson, John E.; Weyandt, Charles J.

    1987-01-01

    The economic and financial aspects of newly defined space-based activities, procedures, and operations (APOs) and associated satellite system designs are presented that have the potential to improve economic performance of future geostationary communications satellites. Launch insurance, launch costs, and the economics of APOs are examined. Retrieval missions and various Space Station scenarios are addressed. The potential benefits of the new APOs to the commercial communications satellite system operator are quantified.

  13. East–West GEO Satellite Station-Keeping with Degraded Thruster Response

    OpenAIRE

    Stoian Borissov; Yunhe Wu; Daniele Mortari

    2015-01-01

    The higher harmonic terms of Earth’s gravitational potential slowly modify the nominal longitude of geostationary Earth orbit (GEO) satellites, while the third-body presence (Moon and Sun) mainly affects their latitude. For this reason, GEO satellites periodically need to perform station-keeping maneuvers, namely, east–west and north–south maneuvers to compensate for longitudinal and latitudinal variations, respectively. During the operational lifetime of GEO satellites, the thrusters’ respon...

  14. 78 FR 19172 - Earth Stations Aboard Aircraft Communicating with Fixed-Satellite Service Geostationary-Orbit...

    Science.gov (United States)

    2013-03-29

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 2 and 25 Earth Stations Aboard Aircraft Communicating with Fixed-Satellite Service Geostationary-Orbit Space Stations AGENCY: Federal Communications Commission. ACTION: Proposed rule;...

  15. Optimal link budget to maximize data receiving from remote sensing satellite at different ground stations

    Science.gov (United States)

    Godse, Vinay V.; Rukmini, B.

    2016-10-01

    Earth observation satellite plays a significant role for global situation awareness. The earth observation satellite uses imaging payloads in RF and IR bands, which carry huge amount of data, needs to be transferred during visibility of satellite over the ground station. Location of ground station plays a very important role in communication with LEO satellites, as orbital speed of LEO satellite is much higher than earth rotation speed. It will be accessible for particular equatorial ground station for a very short duration. In this paper we want to maximize data receiving by optimizing link budget and receiving data at higher elevation links. Data receiving at multiple ground stations is preferred to counter less pass duration due to higher elevation links. Our approach is to calculate link budget for remote sensing satellite with a fixed power input and varying different minimum elevation angles to obtain maximum data. The minimum pass duration should be above 3 minutes for effective communication. We are proposing to start process of command handling as soon as satellite is visible to particular ground station with low elevation angle up to 5 degree and start receiving data at higher elevation angles to receive data with higher speed. Cartosat-2B LEO earth observation satellite is taken for the case study. Cartosat-2B will complete around 14 passes over equator in a day, out of which only 4-5 passes will be useful for near equator ground stations. Our aim is to receive data at higher elevation angles at higher speed and increase amount of data download, criteria being minimum pass duration of 3 minutes, which has been set for selecting minimum elevation angle.

  16. 37 CFR 258.4 - Royalty fee for secondary transmission of digital signals of broadcast stations by satellite...

    Science.gov (United States)

    2010-07-01

    ... transmission of digital signals of broadcast stations by satellite carriers. 258.4 Section 258.4 Patents... AND PROCEDURES ADJUSTMENT OF ROYALTY FEE FOR SECONDARY TRANSMISSIONS BY SATELLITE CARRIERS § 258.4 Royalty fee for secondary transmission of digital signals of broadcast stations by satellite carriers....

  17. 37 CFR 258.3 - Royalty fee for secondary transmission of analog signals of broadcast stations by satellite...

    Science.gov (United States)

    2010-07-01

    ... transmission of analog signals of broadcast stations by satellite carriers. 258.3 Section 258.3 Patents... AND PROCEDURES ADJUSTMENT OF ROYALTY FEE FOR SECONDARY TRANSMISSIONS BY SATELLITE CARRIERS § 258.3 Royalty fee for secondary transmission of analog signals of broadcast stations by satellite carriers....

  18. Optimization and Feasibility Analysis of Satellite Earth Station Power System Using Homer

    Directory of Open Access Journals (Sweden)

    Hassen T. Dorrah

    2012-06-01

    Full Text Available Satellite earth stations which located in remote areas are one of many applications powered by the renewable energy sources. Ground system consists of ground station and control centers working together to support the spacecraft and the data user. Earth station consists of major subsystems, transmitter, receiver, antenna, tracking equipment, terrestrial interface equipment and power supply. Power subsystem is an important part that required for supplying the earth station with electrical power to continue communicating with its remote sensing satellite. This paper deals with simulation and optimal sizing of earth station power system using HOMER software. A combination of two energy sources (solar, and wind to provide a continuous electric power production is used to determine the optimum system operation. Three system configurations are compared with respect to the total net present cost (NPC and levelized cost of energy (COE. Also, economical study will be analyzed for energy demand and sensitivity analysis will be performed.

  19. Optimization and Feasibility Analysis of Satellite Earth Station Power System Using Homer

    Directory of Open Access Journals (Sweden)

    Hassen T. Dorrah

    2012-06-01

    Full Text Available Satellite earth stations which located in remote areas are one of many applications powered by the renewable energy sources. Ground system consists of ground station and control centers working together to support the spacecraft and the data user. Earth station consists of major subsystems, transmitter, receiver, antenna, tracking equipment, terrestrial interface equipment and power supply. Power subsystem is an important part that required for supplying the earth station with electrical power to continue communicating with its remote sensing satellite. This paper deals with simulation and optimal sizing of earth station power system using HOMER software. A combination of two energy sources (solar, and wind to provide a continuous electric power production is used to determine the optimum system operation. Three system configurations are compared with respect to the total net present cost (NPC and levelized cost of energy (COE. Also, economical study will be analyzed for energy demand and sensitivity analysis will be performed.

  20. Global solar radiation: comparison of satellite-based climatology with station records

    Science.gov (United States)

    Skalak, Petr; Zahradnicek, Pavel; Stepanek, Petr; Farda, Ales

    2016-04-01

    We analyze surface incoming shortwave radiation (SIS) from the SARAH dataset prepared by the EUMETSAT Climate Monitoring Satellite Applications Facility from satellite observations of the visible channels of the MVIRI and SEVIRI instruments onboard the geostationary Meteosat satellites. The satellite SIS data are evaluated within the period 1984-2014 on various time scales: from individual months and years to long-term climate means. The validation is performed using the ground measurements of global solar radiation (GLBR) carried out on 11 meteorological stations of the Czech Hydrometeorological Institute in the Czech Republic with at least 30 years long data series. Our aim is to explore whether the SIS data could potentially serve as an alternative source of information on GLBR outside of a relatively sparse network of meteorological stations recording GLBR. Acknowledgement: Supported by the Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Program I (NPU I), grant number LO1415.

  1. Bit Error Rate Due to Misalignment of Earth Station Antenna Pointing to Satellite

    Directory of Open Access Journals (Sweden)

    Wahyu Pamungkas

    2010-04-01

    Full Text Available One problem causing reduction of energy in satellite communications system is the misalignment of earth station antenna pointing to satellite. Error in pointing would affect the quality of information signal to energy bit in earth station. In this research, error in pointing angle occurred only at receiver (Rx antenna, while the transmitter (Tx antennas precisely point to satellite. The research was conducted towards two satellites, namely TELKOM-1 and TELKOM-2. At first, measurement was made by directing Tx antenna precisely to satellite, resulting in an antenna pattern shown by spectrum analyzer. The output from spectrum analyzers is drawn with the right scale to describe swift of azimuth and elevation pointing angle towards satellite. Due to drifting from the precise pointing, it influenced the received link budget indicated by pattern antenna. This antenna pattern shows reduction of power level received as a result of pointing misalignment. As a conclusion, the increasing misalignment of pointing to satellite would affect in the reduction of received signal parameters link budget of down-link traffic.

  2. Determination of the position of the Station Borowiec No. 7811 by satellite laser observations.

    Science.gov (United States)

    Dobaczewská, W.; Drozyner, A.; Rutkowska, M.; Schillak, S.; Zieliňski, J. B.

    Laser observations were performed in Borowiec in three years 1977 - 79 of the satellites Geos A and Geos C. These data were processed by means of the program ORBITA and station coordinates were calculated by dynamical methods. Another solution was found with the processing by the program GRIPE of SAO. These two dynamical solutions are compared with the translocation solution Wettzel-Borowiec.

  3. 47 CFR 25.210 - Technical requirements for space stations in the Fixed-Satellite Service.

    Science.gov (United States)

    2010-10-01

    ... Service shall have a minimum capability to change transponder saturation flux densities by ground command... spatially independent beams. (g)-(h) (i)(1) Space station antennas in the Fixed-Satellite Service, other than antennas in the 17/24 GHz BSS, must be designed to provide a cross-polarization isolation...

  4. Piracy of Satellite Signals by Domestic Receive-Only Earth Stations.

    Science.gov (United States)

    Homan, Steven D.

    Innovations in technology have enabled homeowners to pirate satellite signals intended for cable television operators through the use of home earth-stations. Section 605 of the Communications Act of 1934, which governs reception of signals, is inadequate to regulate this situation because it appears that publication of received programing outside…

  5. East–West GEO Satellite Station-Keeping with Degraded Thruster Response

    Directory of Open Access Journals (Sweden)

    Stoian Borissov

    2015-09-01

    Full Text Available The higher harmonic terms of Earth’s gravitational potential slowly modify the nominal longitude of geostationary Earth orbit (GEO satellites, while the third-body presence (Moon and Sun mainly affects their latitude. For this reason, GEO satellites periodically need to perform station-keeping maneuvers, namely, east–west and north–south maneuvers to compensate for longitudinal and latitudinal variations, respectively. During the operational lifetime of GEO satellites, the thrusters’ response when commanded to perform these maneuvers slowly departs from the original nominal impulsive behavior. This paper addresses the practical problem of how to perform reliable east–west station-keeping maneuvers when thruster response is degraded. The need for contingency intervention from ground-based satellite operators is reduced by breaking apart the scheduled automatic station-keeping maneuvers into smaller maneuvers. Orbital alignment and attitude are tracked on-board during and in between sub-maneuvers, and any off nominal variations are corrected for with subsequent maneuvers. These corrections are particularly important near the end of the lifetime of GEO satellites, where thruster response is farthest from nominal performance.

  6. Space Station needs, attributes and architectural options. Volume 2, book 1, part 3: Manned Space Station relevance to commercial telecommunications satellites

    Science.gov (United States)

    1983-01-01

    A document containing a forecast of satellite traffic and revelant technology trends to the year 2000 was prepared which includes those space station capabilities and characteristics that should be provided to make the station useful to commercial satellite owners. The document was circulated to key representative organizations within the commercial telecommunications satellite and related communities of interest, including spacecraft manufacturers, commercial satellite owners, communications carriers, networks and risk insurers. The prospectus document is presented as well as the transmittal letter and the mailing list of the people and companies that were asked to review it. Key commercial telecommunications comments are summarized the actual response letters from the industry are included.

  7. Influence of urbanization on the thermal environment of meteorological station:Satellite-observed evidence

    Institute of Scientific and Technical Information of China (English)

    SHI Tao; HUANG Yong; WANG Hong; SHI Chun-E; YANG Yuan-Jian

    2015-01-01

    In this paper, five national meteorological stations in Anhui province are taken as typical examples to explore the effects of local urbanization on their thermal environment by using Landsat data from 1990 to 2010. Satellite-based land use/land cover (LULC), land surface temperature (LST), normalized difference vegetation index (NDVI) are used to investigate the effects. The study shows that LULC around meteorological stations changed significantly due to urban expansion. Fast urbanization is the main factor that affects the spatial-temporal distribution of thermal environment around meteorological stations. Moreover, the normalized LST and NDVI exhibit strong inverse correlations around meteorological stations, so the variability of LST can be monitored through evaluating the variability of NDVI. In addition, station-relocation plays an important role in improving representativeness of thermal environment. Notably, the environment representativeness was improved, but when using the data from the station to study climate change, the relocation-induced inhomogeneous data should be considered and adjusted. Consequently, controlling the scale and layout of the urban buildings and constructions around meteorological stations is an effective method to ameliorate observational thermal environment and to improve regional representativeness of station observation. The present work provides observational evidences that high resolution Landsat images can be used to evaluate the thermal environment of meteorological stations.

  8. Energy-Efficient Network Transmission between Satellite Swarms and Earth Stations Based on Lyapunov Optimization Techniques

    Directory of Open Access Journals (Sweden)

    Weiwei Fang

    2014-01-01

    Full Text Available The recent advent of satellite swarm technologies has enabled space exploration with a massive number of picoclass, low-power, and low-weight spacecraft. However, developing swarm-based satellite systems, from conceptualization to validation, is a complex multidisciplinary activity. One of the primary challenges is how to achieve energy-efficient data transmission between the satellite swarm and terrestrial terminal stations. Employing Lyapunov optimization techniques, we present an online control algorithm to optimally dispatch traffic load among different satellite-ground links for minimizing overall energy consumption over time. Our algorithm is able to independently and simultaneously make control decisions on traffic dispatching over intersatellite-links and up-down-links so as to offer provable energy and delay guarantees, without requiring any statistical information of traffic arrivals and link condition. Rigorous analysis and extensive simulations have demonstrated the performance and robustness of the proposed new algorithm.

  9. Paving the Way for Small Satellite Access to Orbit: Cyclops' Deployment of SpinSat, the Largest Satellite Ever Deployed from the International Space Station

    Science.gov (United States)

    Hershey, Matthew P.; Newswander, Daniel R.; Smith, James P.; Lamb, Craig R.; Ballard, Perry G.

    2015-01-01

    The Space Station Integrated Kinetic Launcher for Orbital Payload Systems (SSIKLOPS), known as "Cyclops" to the International Space Station (ISS) community, successfully deployed the largest satellite ever (SpinSat) from the ISS on November 28, 2014. Cyclops, a collaboration between the NASA ISS Program, NASA Johnson Space Center Engineering, and Department of Defense Space Test Program (DoD STP) communities, is a dedicated 10-100 kg class ISS small satellite deployment system. This paper will showcase the successful deployment of SpinSat from the ISS. It will also outline the concept of operations, interfaces, requirements, and processes for satellites to utilize the Cyclops satellite deployment system.

  10. M-cadherin-mediated intercellular interactions activate satellite cell division.

    Science.gov (United States)

    Marti, Merce; Montserrat, Núria; Pardo, Cristina; Mulero, Lola; Miquel-Serra, Laia; Rodrigues, Alexandre Miguel Cavaco; Andrés Vaquero, José; Kuebler, Bernd; Morera, Cristina; Barrero, María José; Izpisua Belmonte, Juan Carlos

    2013-11-15

    Adult muscle stem cells and their committed myogenic precursors, commonly referred to as the satellite cell population, are involved in both muscle growth after birth and regeneration after damage. It has been previously proposed that, under these circumstances, satellite cells first become activated, divide and differentiate, and only later fuse to the existing myofiber through M-cadherin-mediated intercellular interactions. Our data show that satellite cells fuse with the myofiber concomitantly to cell division, and only when the nuclei of the daughter cells are inside the myofiber, do they complete the process of differentiation. Here we demonstrate that M-cadherin plays an important role in cell-to-cell recognition and fusion, and is crucial for cell division activation. Treatment of satellite cells with M-cadherin in vitro stimulates cell division, whereas addition of anti-M-cadherin antibodies reduces the cell division rate. Our results suggest an alternative model for the contribution of satellite cells to muscle development, which might be useful in understanding muscle regeneration, as well as muscle-related dystrophies.

  11. The geo-control system for station keeping and colocation of geostationary satellites

    Science.gov (United States)

    Montenbruck, O.; Eckstein, M. C.; Gonner, J.

    1993-01-01

    GeoControl is a compact but powerful and accurate software system for station keeping of single and colocated satellites, which has been developed at the German Space Operations Center. It includes four core modules for orbit determination (including maneuver estimation), maneuver planning, monitoring of proximities between colocated satellites, and interference and event prediction. A simple database containing state vector and maneuver information at selected epochs is maintained as a central interface between the modules. A menu driven shell utilizing form screens for data input serves as the central user interface. The software is written in Ada and FORTRAN and may be used on VAX workstations or mainframes under the VMS operating system.

  12. Determination of the position of the station Borowiec Nr 7811 by satellite laser observations

    Science.gov (United States)

    Dobaczewska, W.; Drozyner, A.; Rutkowska, M.; Schillak, S.; Zielinski, J. B.

    Laser observations during 1977-1979 of the GEOS-1 and GEOS-3 satellites, used to determine the geocentric position of the Astronomical Latitude Observatory in Borowiec (station No. 7811) are examined. The data are processed by means of the ORBITA program and the GRIPE program elaborated at the Smithsonian Astrophysical Observatory. The coordinates of the station are calculated by a dynamical orbital method. Results of the ORBITA and GRIPE solutions are presented in tables. A comparison of these two solutions with the Wettzel-Borowiec translocation solution is considered.

  13. Climate Monitoring Network on Maunakea - Master Station at Summit and Lower Elevation Satellite Stations

    Science.gov (United States)

    McKenzie, M. M.; Klasner, F.; Giambelluca, T. W.; Businger, S.

    2014-12-01

    Maunakea, a dormant shield volcano on the Big Island of Hawai'i, rises 13,796 feet above sea level, making it the highest point in the Pacific Basin. From sea floor to summit, it's the tallest mountain in the world. The high elevation, low air and light pollution, as well as dry weather year round make it the best location in the world for astronomy observations. The summit is home to 13 ground based telescope facilities. Like all alpine regions, it is an extremely fragile and unique ecosystem because of the harsh conditions and short growing seasons located at high altitudes. The summit is home to several federal and/or state protected species. It supports 11 species of arthropods found nowhere else on Earth. Most noted of these is the Wēkiu bug, whose habitat has been altered by the infrastructural development on the mountain. Arthropod habitat model development has highlighted gaps in climate information, for example, lack of climate precipitation data, snow data and reliable temperature data. Furthermore, in tropical regions, precipitation is the most variable climate component due to topography and local winds. The telescopes collect weather data for the purpose of knowing when it is dry and clear for astronomical observation. Although existing weather stations associated with the telescopes meet some weather and climate monitoring needs, it cannot address the full range of issues needed due to technological limitation and site design. Precipitation does not occur often and is likely to be in the form of snow or ice. Snow cover data has not been directly recorded despite astronomical recording of other meteorological data that began in the1960s. Therefore, the need to monitor the weather and climate in a long-term and well-calibrated way is critical for management of the ecosystems on the slopes of Maunakea. Long-term weather and climate monitoring stations are the primary building blocks for research partnerships, which encourage collaboration and ultimately

  14. Comparison of microwave satellite humidity data and radiosonde profiles: a survey of European stations

    Directory of Open Access Journals (Sweden)

    V. O. John

    2005-03-01

    Full Text Available A method to compare upper tropospheric humidity (UTH from satellite and radiosonde data has been applied to the European radiosonde stations. The method uses microwave data as a benchmark for monitoring the performance of the stations. The present study utilizes three years (2002–2003 of data from channel 18 (183.31±1.00 GHz of the Advanced Microwave Sounding Unit-B (AMSU-B aboard the satellites NOAA-15 and NOAA-16. The comparison is done in the radiance space, the radiosonde data were transformed to the channel radiances using a radiative transfer model. The comparison results confirm that there is a dry bias in the UTH measured by the radiosondes. This bias is highly variable among the stations and the years. This variability is attributed mainly to the differences in the radiosonde humidity measurements. The results also hint at a systematic difference between the two satellites, the channel 18 brightness temperature of NOAA-15 is on average 1.0 K higher than that of NOAA-16. The difference of 1 K corresponds to approximately 7% relative error in UTH which is significant for climatological applications.

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

    Science.gov (United States)

    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.

  16. A compact and low cost TT&C S-Band Ground Station for low orbit satellites

    Science.gov (United States)

    Pacola, Luiz C.; Ferrari, Carlos A.

    Instituto Nacional de Pesquisas Espaciais (INPE's) S-Band Ground Station for satellite control and monitoring is revised consdiering the current software and hardware technology. A Ground Station concept for low orbit satellites is presented. The front-end uses a small antenna and low cost associated equipment without loss of performance. The baseband equipment is highly standardized and developed on a personal computer IBM compatible using extensively Digital Signal Processing (DSP). A link budget for ranging, telecommand and telemetry is also presented.

  17. Precise Orbit Determination of BeiDou Satellites with Contributions from Chinese National Continuous Operating Reference Stations

    Directory of Open Access Journals (Sweden)

    Ming Chen

    2017-08-01

    Full Text Available The precise orbit determination (POD for BeiDou satellites is usually limited by the insufficient quantity and poor distribution of ground tracking stations. To cope with this problem, this study used the GPS and BeiDou joint POD method based on Chinese national continuous operating reference stations (CNCORS and IGS/MGEX stations. The results show that the 3D RMS of the differences of overlapping arcs is better than 22 cm for geostationary orbit (GEO satellites and better than 10 cm for inclined geosynchronous orbit (IGSO and medium earth orbit (MEO satellites. The radial RMS is better than 2 cm for all three types of BeiDou satellites. The results of satellite laser ranging (SLR residuals show that the RMS of the IGSO and MEO satellites is better than 5 cm, whereas the GEO satellite has a systematic bias. This study investigates the contributions of CNCORS to the POD of BeiDou satellites. The results show that after the incorporation of CNCORS, the precision of overlapping arcs of the GEO, IGSO, and MEO satellites is improved by 15.5%, 57.5%, and 5.3%, respectively. In accordance with the improvement in the precision of overlapping arcs, the accuracy of the IGSO and MEO satellites assessed by the SLR is improved by 30.1% and 4.8%, respectively. The computation results and analysis demonstrate that the inclusion of CNCORS yields the biggest contribution in the improvement of orbit accuracy for IGSO satellites, when compared to GEO satellites, while the orbit improvement for MEO satellites is the lowest due to their global coverage.

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

    Energy Technology Data Exchange (ETDEWEB)

    S, Motty G, E-mail: mottygs@gmail.com; Satyanarayana, M., E-mail: mottygs@gmail.com; Krishnakumar, V., E-mail: mottygs@gmail.com; Dhaman, Reji k., E-mail: mottygs@gmail.com [Department of Optoelectronics, University of Kerala, Kariavattom, Trivandrum-695 581, Kerala (India)

    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.

  19. Minimum-fuel station-change for geostationary satellites using low-thrust considering perturbations

    Science.gov (United States)

    Zhao, ShuGe; Zhang, JingRui

    2016-10-01

    The objective of this paper is to find the minimum-fuel station change for geostationary satellites with low-thrust while considering significant perturbation forces for geostationary Earth orbit (GEO). The effect of Earth's triaxiality, lunisolar perturbations, and solar radiation pressure on the terminal conditions of a long duration GEO transfer is derived and used for establishing the station change model with consideration of significant perturbation forces. A method is presented for analytically evaluating the effect of Earth's triaxiality on the semimajor axis and longitude during a station change. The minimum-fuel problem is solved by the indirect optimization method. The easier and related minimum-energy problem is first addressed and then the energy-to-fuel homotopy is employed to finally obtain the solution of the minimum-fuel problem. Several effective techniques are employed in solving the two-point boundary-value problem with a shooting method to overcome the problem of the small convergence radius and the sensitivity of the initial costate variables. These methods include normalization of the initial costate vector, computation of the analytic Jacobians matrix, and switching detection. The simulation results show that the solution of the minimum-fuel station change with low-thrust considering significant perturbation forces can be obtained by applying these preceding techniques.

  20. Teachers guide for building and operating weather satellite ground stations for high school science

    Science.gov (United States)

    Summers, R. J.; Gotwald, T.

    1981-01-01

    A number of colleges and universities are operating APT direct readout stations. However, high school science teachers have often failed to realize the potential of meteorological satellites and their products as unique instructional tools. The ability to receive daily pictures from these satellites offers exciting opportunities for secondary school teachers and students to assemble the electronic hardware and to view real time pictures of Earth from outer space. The station and pictures can be used in the classroom to develop an approach to science teaching that could span many scientific disciplines and offer many opportunities for student research and participation in scientific processes. This can be accomplished with relatively small expenditures of funds for equipment. In most schools some of the equipment may already be available. Others can be constructed by teachers and/or students. Yet another source might be the purchase of used equipment from industry or through the government surplus channels. The information necessary for individuals unfamiliar with these systems to construct a direct readout for receiving real time APT photographs on a daily basis in the classroom is presented.

  1. The Design and Application of Data Storage System in Miyun Satellite Ground Station

    Science.gov (United States)

    Xue, Xiping; Su, Yan; Zhang, Hongbo; Liu, Bin; Yao, Meijuan; Zhao, Shu

    2015-04-01

    China has launched Chang'E-3 satellite in 2013, firstly achieved soft landing on moon for China's lunar probe. Miyun satellite ground station firstly used SAN storage network system based-on Stornext sharing software in Chang'E-3 mission. System performance fully meets the application requirements of Miyun ground station data storage.The Stornext file system is a sharing file system with high performance, supports multiple servers to access the file system using different operating system at the same time, and supports access to data on a variety of topologies, such as SAN and LAN. Stornext focused on data protection and big data management. It is announced that Quantum province has sold more than 70,000 licenses of Stornext file system worldwide, and its customer base is growing, which marks its leading position in the big data management.The responsibilities of Miyun satellite ground station are the reception of Chang'E-3 satellite downlink data and management of local data storage. The station mainly completes exploration mission management, receiving and management of observation data, and provides a comprehensive, centralized monitoring and control functions on data receiving equipment. The ground station applied SAN storage network system based on Stornext shared software for receiving and managing data reliable.The computer system in Miyun ground station is composed by business running servers, application workstations and other storage equipments. So storage systems need a shared file system which supports heterogeneous multi-operating system. In practical applications, 10 nodes simultaneously write data to the file system through 16 channels, and the maximum data transfer rate of each channel is up to 15MB/s. Thus the network throughput of file system is not less than 240MB/s. At the same time, the maximum capacity of each data file is up to 810GB. The storage system planned requires that 10 nodes simultaneously write data to the file system through 16

  2. The Role of Anchor Stations in the Validation of Earth Observation Satellite Data and Products. The Valencia and the Alacant Anchor Stations

    Science.gov (United States)

    Lopez-Baeza, Ernesto; Geraldo Ferreira, A.; Saleh-Contell, Kauzar

    Space technology facilitates humanity and science with a global revolutionary view of the Earth through the acquisition of Earth Observation satellite data. Satellites capture information over different spatial and temporal scales and assist in understanding natural climate processes and in detecting and explaining climate change. Accurate Earth Observation data is needed to describe climate processes by improving the parameterisations of different climate elements. Algorithms to produce geophysical parameters from raw satellite observations should go through selection processes or participate in inter-comparison programmes to ensure performance reliability. Geophysical parameter datasets, obtained from satellite observations, should pass a quality control before they are accepted in global databases for impact, diagnostic or sensitivity studies. Calibration and Validation, or simply "Cal/Val", is the activity that endeavours to ensure that remote sensing products are highly consistent and reproducible. This is an evolving scientific activity that is becoming increasingly important as more long-term studies on global change are undertaken, and new satellite missions are launched. Calibration is the process of quantitatively defining the system responses to known, controlled signal inputs. Validation refers to the process of assessing, by independent means, the quality of the data products derived from the system outputs. These definitions are generally accepted and most often used in the remote sensing context to refer specifically and respectively to sensor radiometric calibration and geophysical parameter validation. Anchor Stations are carefully selected locations at which instruments measure quantities that are needed to run, calibrate or validate models and algorithms. These are needed to quanti-tatively evaluate satellite data and convert it into geophysical information. The instruments collect measurements of basic quantities over a long timescale

  3. Relativistic electrons high doses at International Space Station and Foton M2/M3 satellites

    Science.gov (United States)

    Dachev, T. P.; Tomov, B.; Matviichuk, Yu.; Dimitrov, Pl.; Bankov, N.

    2009-12-01

    The paper presents observation of relativistic electrons. Data are collected by the Radiation Risk Radiometer-Dosimeters (R3D) B2/B3 modifications during the flights of Foton M2/M3 satellites in 2005 and 2007 as well as by the R3DE instrument at the European Technology Exposure Facility (EuTEF) on the Columbus External Payload Adaptor at the International Space Station (ISS) in the period February 20 - April 28, 2008. On the Foton M2/M3 satellites relativistic electrons are observed more frequently than on the ISS because of higher (62.8°) inclination of the orbit. At both Foton satellites the usual duration of the observations are a few minutes long. On the ISS the duration usually is about 1 min or less. The places of observations of high doses due to relativistic electrons are distributed mainly at latitudes above 50° geographic latitude in both hemispheres on Foton M2/M3 satellites. A very high maximum is found in the southern hemisphere at longitudinal range 0°-60°E. At the ISS the maximums are observed between 45° and 52° geographic latitude in both hemispheres mainly at longitudes equatorward from the magnetic poles. The measured absolute maximums of dose rates generated by relativistic electrons are found to be as follows: 304 μGy h -1 behind 1.75 g cm -2 shielding at Foton M2, 2314 μGy h -1 behind 0.71 g cm -2 shielding at Foton M3 and 19,195 μGy h -1 (Flux is 8363 cm -2 s -1) behind les than 0.4 g cm -2 shielding at ISS.

  4. 78 FR 14920 - Earth Stations Aboard Aircraft Communicating With Fixed-Satellite Service Geostationary-Orbit...

    Science.gov (United States)

    2013-03-08

    ... forwarding and receiving communications signals via a system of satellites or reselling satellite... specialized telecommunications services, such as satellite tracking, communications telemetry, and radar... of Subjects in 47 CFR Parts 2 and 25 Frequency allocations, Satellites. Federal Communications...

  5. Information management system: A summary discussion. [for use in the space shuttle sortie, modular space station and TDR satellite

    Science.gov (United States)

    Sayers, R. S.

    1972-01-01

    An information management system is proposed for use in the space shuttle sortie, the modular space station, the tracking data relay satellite and associated ground support systems. Several different information management functions, including data acquisition, transfer, storage, processing, control and display are integrated in the system.

  6. Determination of SLR station coordinates on the basis of tracking 45 GNSS satellites: benefits for future ITRF realizations

    Science.gov (United States)

    Sośnica, Krzysztof; Bury, Grzegorz; Zajdel, Radosław; Kaźmierski, Kamil; Drożdżewski, Mateusz

    2017-04-01

    The SLR station coordinates and SLR-derived Earth Rotation Parameters (ERPs) are typically derived on the basis of SLR tracking of four spherical geodetic satellites: two LAGEOS and two Etalons. Between 2014 and 2016, the International Laser Ranging Service (ILRS) initiated four intensive SLR tracking campaigns for Galileo and three campaigns devoted to tracking all GNSS spacecraft. As a result, the number of SLR observations and the number of tracked GNSS satellites have dramatically increased allowing for determining SLR station coordinates and ERPs solely on the basis of SLR tracking of GNSS satellites. This paper shows, for the first time, the solution in which the SLR station coordinates, geocenter motion, and ERPs are determined using the SLR observations to 26 GLONASS, 14 Galileo, 2 BeiDou IGSO, 2 BeiDou MEO, and 1 QZSS satellite. We compare the SLR station coordinate stability derived from GNSS-based results to the LAGEOS-only solution and from a combined 'SLR to GNSS+LAGEOS' solution. We address the issues related to the GNSS orbit determination using sparse SLR data and the issues related to handling range biases in the GNSS solutions. We found that the coordinate stability of those SLR stations which provide a large number of GNSS observations can remarkably be improved. The Length-of-day parameter can be derived from SLR-GNSS solutions with a much better accuracy than from the LAGEOS-only solutions. Finally, we show that the SLR tracking of GNSS satellites improves the consistency between SLR and GNSS solutions, and thus, can be beneficial for the future ITRF realizations.

  7. Merged dust climatology in Phoenix, Arizona based on satellite and station data

    Science.gov (United States)

    Lei, Hang; Wang, Julian X. L.; Tong, Daniel Q.; Lee, Pius

    2016-11-01

    In order to construct climate quality long-term dust storm dataset, merged dust storm climatology in Phoenix is developed based on three data sources: regular meteorological records, in situ air quality measurements, and satellite remote sensing observations. The result presented in this paper takes into account the advantages of each dataset and integrates individual analyses demonstrated and presented in previous studies that laid foundation to reconstruct a consistent and continuous time series of dust frequency. A key for the merging procedure is to determine analysis criteria suitable for each individual data source. A practical application to historic records of dust storm activities over the Phoenix area is presented to illustrate detailed steps, advantages, and limitations of the newly developed process. Three datasets are meteorological records from the Sky Harbor station, satellite observed aerosol optical depth data from moderate resolution imaging spectroradiometer, and the U.S. Environmental Protection Agency Air Quality System particulate matter data of eight sites surrounding Phoenix. Our purpose is to construct dust climatology over the Phoenix region for the period 1948-2012. Data qualities of the reconstructed dust climatology are assessed based on the availability and quality of the input data. The period during 2000-2012 has the best quality since all datasets are well archived. The reconstructed climatology shows that dust storm activities over the Phoenix region have large interannual variability. However, seasonal variations show a skewed distribution with higher frequency of dust storm activities in July and August and relatively quiet during the rest of months. Combining advantages of all the available datasets, this study presents a merged product that provides a consistent and continuous time series of dust storm activities suitable for climate studies.

  8. Correlation Between the "seeing FWHM" of Satellite Optical Observations and Meteorological Data at the OWL-Net Station, Mongolia

    Science.gov (United States)

    Bae, Young-Ho; Jo, Jung Hyun; Yim, Hong-Suh; Park, Young-Sik; Park, Sun-Youp; Moon, Hong Kyu; Choi, Young-Jun; Jang, Hyun-Jung; Roh, Dong-Goo; Choi, Jin; Park, Maru; Cho, Sungki; Kim, Myung-Jin; Choi, Eun-Jung; Park, Jang-Hyun

    2016-06-01

    The correlation between meteorological data collected at the optical wide-field patrol network (OWL-Net) Station No. 1 and the seeing of satellite optical observation data was analyzed. Meteorological data and satellite optical observation data from June 2014 to November 2015 were analyzed. The analyzed meteorological data were the outdoor air temperature, relative humidity, wind speed, and cloud index data, and the analyzed satellite optical observation data were the seeing full-width at half-maximum (FWHM) data. The annual meteorological pattern for Mongolia was analyzed by collecting meteorological data over four seasons, with data collection beginning after the installation and initial set-up of the OWL-Net Station No. 1 in Mongolia. A comparison of the meteorological data and the seeing of the satellite optical observation data showed that the seeing degrades as the wind strength increases and as the cloud cover decreases. This finding is explained by the bias effect, which is caused by the fact that the number of images taken on the less cloudy days was relatively small. The seeing FWHM showed no clear correlation with either temperature or relative humidity.

  9. Changes in satellite-derived impervious surface area at US historical climatology network stations

    Science.gov (United States)

    Gallo, Kevin; Xian, George

    2016-10-01

    The difference between 30 m gridded impervious surface area (ISA) between 2001 and 2011 was evaluated within 100 and 1000 m radii of the locations of climate stations that comprise the US Historical Climatology Network. The amount of area associated with observed increases in ISA above specific thresholds was documented for the climate stations. Over 32% of the USHCN stations exhibited an increase in ISA of ⩾20% between 2001 and 2011 for at least 1% of the grid cells within a 100 m radius of the station. However, as the required area associated with ISA change was increased from ⩾1% to ⩾10%, the number of stations that were observed with a ⩾20% increase in ISA between 2001 and 2011 decreased to 113 (9% of stations). When the 1000 m radius associated with each station was examined, over 52% (over 600) of the stations exhibited an increase in ISA of ⩾20% within at least 1% of the grid cells within that radius. However, as the required area associated with ISA change was increased to ⩾10% the number of stations that were observed with a ⩾20% increase in ISA between 2001 and 2011 decreased to 35 (less than 3% of the stations). The gridded ISA data provides an opportunity to characterize the environment around climate stations with a consistently measured indicator of a surface feature. Periodic evaluations of changes in the ISA near the USHCN and other networks of stations are recommended to assure the local environment around the stations has not significantly changed such that observations at the stations may be impacted.

  10. The Use of Chaff in Space as a Jamming Device between Ground Stations and Satellites

    Science.gov (United States)

    1988-12-01

    of Fi•Yu es Figure Page 1. Rasic Orbital Parameters . . . . . . . .... 2. Satellite Orientation for Cases I, II, III, and IV...Moti r on Spin Direction PCe of sot on c.SSO..!Path of notion Case.X AngLe of Tk~t Case-III Cast IV Figure 2. SatelLite Orientation for Cases I, II

  11. Satellite range scheduling with the priority constraint: An improved genetic algorithm using a station ID encoding method

    Directory of Open Access Journals (Sweden)

    Li Yuqing

    2015-06-01

    Full Text Available Satellite range scheduling with the priority constraint is one of the most important problems in the field of satellite operation. This paper proposes a station coding based genetic algorithm to solve this problem, which adopts a new chromosome encoding method that arranges tasks according to the ground station ID. The new encoding method contributes to reducing the complexity in conflict checking and resolving, and helps to improve the ability to find optimal resolutions. Three different selection operators are designed to match the new encoding strategy, namely random selection, greedy selection, and roulette selection. To demonstrate the benefits of the improved genetic algorithm, a basic genetic algorithm is designed in which two cross operators are presented, a single-point crossover and a multi-point crossover. For the purpose of algorithm test and analysis, a problem-generating program is designed, which can simulate problems by modeling features encountered in real-world problems. Based on the problem generator, computational results and analysis are made and illustrated for the scheduling of multiple ground stations.

  12. The SPectral Ocean Color (SPOC) Small Satellite Mission: From Payload to Ground Station Development and Everything in Between

    Science.gov (United States)

    Bernardes, S.; Cotten, D. L.

    2016-12-01

    This work introduces the mission concept, technologies, and development status for the measuring SPectral Ocean Color (SPOC) small satellite mission, which will use a hyperspectral imager to map sensitive coastal regions and off coast water quality near the state of Georgia and beyond. SPOC is being developed by The University of Georgia's Small Satellite Research Laboratory (SSRL) with funds from NASA's Undergraduate Student Instrument Project (USIP). The project is led by undergraduates from a wide range of backgrounds and supervised by a multidisciplinary team of Principal Investigators. Using optical components, electronics boards, a grating spectrometer, and a CMOS array the students will assemble and integrate the payload components and ensure their compatibility with the other subsystems. In-house development and assembly includes building the hyperspectral imager, as well integrating it into the satellite, and testing of the different subsystems of the satellite. The mission will collect spectral data along a 300 km swath using the grating spectrometer to diffract the incoming radiation into the 440-865 nm spectral range. The resulting images will be 75 km x 300 km in size, have a 120 m spatial resolution, and a spectral resolution of 2 nm, covering 100 spectral bands. The resulting dataset will allow for spectral analysis comparisons with some of NASA's legacy satellites. The work describes the timeline and current progress of the SPOC mission. Focus will be equally distributed to all the different systems of the satellite including their development, testing, and integration. Particular emphasis is given to Attitude Determination and Control System (ADCS), command and data handling (CDH), payload, power generation, S-Band/X-Band transceivers, and the development of ground station capabilities (S-Band/X-Band).

  13. Industry leading satellite based GNSS (Global Navigation Satellite System) positioning and monitoring solutions with real-time CORS (Continuously Operating Reference Station) networks

    Science.gov (United States)

    Janousek, Martin

    2010-05-01

    Real-Time CORS (Continuously Operating Reference Station Networks) today are typically GNSS networks for positioning and monitoring purposes. Real-Time networks can consist of a few stations for a local network up to nation- or continental wide networks with several hundred CORS stations. Such networks use wide area modeling of GNSS error sources including ionospheric, tropospheric and satellite orbit correction parameters to produce highest precision and efficiency method of positioning using GNSS. In 1998 Trimble Navigation Ltd. introduced a method of surveying with a non-physical or computed base station, called VRS (Virtual Reference Station). It is the most widely supported method of producing a network solution for precise carrier phase positioning in the industry. Surveying historically required one base as the fixed point of reference, and one or multiple rovers using that point of reference to compute their location by processing a vector result, either in real-time or in a postprocessed sense. Real-time survey is often referred to as RTK, short for real-time kinematic, and as the name suggests the results are in real time and you can move. The power of VRS is in the ability to compute a real-time wide-area solution to the factors that cause single base methods to degrade with distance. Namely, ionospheric and tropospheric modeling, and satellite orbit corrections. This is achieved by the reference network of CORS. A wide scattering of CORS across a state, typically 50-70km in mid-latitudes, creates a ground based sampling which significantly reduces the distance dependent errors that accumulate in the single base-rover relationship described early. Furthermore, GNSS networks can be used for real-time monitoring purposes at various distance range. Trimble Integrity Manager software provides a suite of motion engines designed to detect and quantify any movement in a range of scales from slow, creeping movement like subsidence, through sudden events such as

  14. Validation of three satellite-derived databases of surface solar radiation using measurements performed at 42 stations in Brazil

    Science.gov (United States)

    Thomas, Claire; Wey, Etienne; Blanc, Philippe; Wald, Lucien

    2016-06-01

    The SoDa website (www.soda-pro.com) is populated with numerous solar-related Web services. Among them, three satellite-derived irradiation databases can be manually or automatically accessed to retrieve radiation values within the geographical coverage of the Meteosat Second Generation (MSG) satellite: the two most advanced versions of the HelioClim-3 database (versions 4 and 5, respectively HC3v4 and HC3v5), and the CAMS radiation service. So far, these databases have been validated against measurements of several stations in Europe and North Africa only. As the quality of such databases depends on the geographical regions and the climates, this paper extends this validation campaign and proposes an extensive comparison on Brazil and global irradiation received on a horizontal surface. Eleven stations from the Brazilian Institute of Space Research (INPE) network offer 1 min observations, and thirty-one stations from the Instituto Nacional de Meteorologia (INMET) network offer hourly observations. The satellite-derived estimates have been compared to the corresponding observations on hourly, daily and monthly basis. The bias relative to the mean of the measurements for HC3v5 is mostly comprised between 1 and 3 %, and that for HC3v4 between 2 and 5 %. These are very satisfactory results and they demonstrate that HC3v5, and to a lesser extent HC3v4, may be used in studies of long-term changes in SSI in Brazil. The situation is not so good with CAMS radiation service for which the relative bias is mostly comprised between 5 and 10 %. For hourly irradiation, the relative RMSE ranges from 15 to 33 %. The correlation coefficient is very large for all stations and the three databases, with an average of 0.96. The three databases reproduce well the hour from hour changes in SSI. The errors show a tendency to increase with the viewing angle of the MSG satellite. They are greater in tropical areas where the relative humidity in the atmosphere is important. It is concluded

  15. Synchronized Position and Hold Reorient Experimental Satellites - International Space Station (SPHERES-ISS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Payload Systems Inc. (PSI) and the MIT Space Systems Laboratory (MIT-SSL) propose an innovative research program entitled SPHERES-ISS that uses their satellite...

  16. Satellite Cells Contribution to Exercise Mediated Muscle Hypertrophy and Repair

    Science.gov (United States)

    Bazgir, Behzad; Fathi, Rouhollah; Rezazadeh Valojerdi, Mojtaba; Mozdziak, Paul; Asgari, Alireza

    2017-01-01

    Satellite cells (SCs) are the most abundant skeletal muscle stem cells. They are widely recognized for their contributions to maintenance of muscle mass, regeneration and hypertrophy during the human life span. These cells are good candidates for cell therapy due to their self-renewal capabilities and presence in an undifferentiated form. Presently, a significant gap exists between our knowledge of SCs behavior and their application as a means for human skeletal muscle tissue repair and regeneration. Both physiological and pathological stimuli potentially affect SCs activation, proliferation, and terminal differentiation the former category being the focus of this article. Activation of SCs occurs following exercise, post-training micro-injuries, and electrical stimulation. Exercise, as a potent and natural stimulus, is at the center of numerous studies on SC activation and relevant fields. According to research, different exercise modalities end with various effects. This review article attempts to picture the state of the art of the SCs life span and their engagement in muscle regeneration and hypertrophy in exercise. PMID:28042532

  17. Satellite Cells Contribution to Exercise Mediated Muscle Hypertrophy and Repair

    Directory of Open Access Journals (Sweden)

    Behzad Bazgir

    2016-10-01

    Full Text Available Satellite cells (SCs are the most abundant skeletal muscle stem cells. They are widely recognized for their contributions to maintenance of muscle mass, regeneration and hypertrophy during the human life span. These cells are good candidates for cell therapy due to their self-renewal capabilities and presence in an undifferentiated form. Presently, a significant gap exists between our knowledge of SCs behavior and their application as a means for human skeletal muscle tissue repair and regeneration. Both physiological and pathological stimuli potentially affect SCs activation, proliferation, and terminal differentiation - the former category being the focus of this article. Activation of SCs occurs following exercise, post-training micro-injuries, and electrical stimulation. Exercise, as a potent and natural stimulus, is at the center of numerous studies on SC activation and relevant fields. According to research, different exercise modalities end with various effects. This review article attempts to picture the state of the art of the SCs life span and their engagement in muscle regeneration and hypertrophy in exercise.

  18. Earth rotation, station coordinates and orbit determination from satellite laser ranging

    Science.gov (United States)

    Murata, Masaaki

    The Project MERIT, a special program of international colaboration to Monitor Earth Rotation and Intercompare the Techniques of observation and analysis, has come to an end with great success. Its major objective was to evaluate the ultimate potential of space techniques such as VLBI and satellite laser ranging, in contrast with the other conventional techniques, in the determination of rotational dynamics of the earth. The National Aerospace Laboratory (NAL) has officially participated in the project as an associate analysis center for satellite laser technique for the period of the MERIT Main Campaign (September 1983-October 1984). In this paper, the NAL analysis center results are presented.

  19. Installing the earth station of Ka-band satellite frequency in Malaysia: conceptual framework for site decision

    Science.gov (United States)

    Mahmud, M. R.; Reba, M. N. M.; Jaw, S. W.; Arsyad, A.; Ibrahim, M. A. M.

    2017-05-01

    This paper developed a conceptual framework in determining the suitable location in installing the earth station for Ka-band satellite communication in Malaysia. This current evolution of high throughput satellites experienced major challenge due to Malaysian climate. Because Ka-band frequency is highly attenuated by the rainfall; it is an enormous challenge to define the most appropriate site for the static communication. Site diversity, a measure to anticipate this conflict by choosing less attenuated region and geographically change the transmission strategy on season basis require accurate spatio-temporal information on the geographical, environmental and hydro-climatology at local scale. Prior to that request, this study developed a conceptual framework to cater the needs. By using the digital spatial data, acquired from site measurement and remote sensing, the proposed framework applied a multiple criteria analysis to perform the tasks of site selection. With the advancement of high resolution remotely sensed data, site determination can be conducted as in Malaysia; accommodating a new, fast, and effective satellite communication. The output of this study is one of the pioneer contributions to create a high tech-society.

  20. Narrow multibeam satellite ground station antenna employing a linear array with a geosynchronous arc coverage of 60 deg. I - Theory

    Science.gov (United States)

    Amitay, N.; Gans, M. J.

    1982-11-01

    The feasibility of using an appropriately squinted linear scan in narrow multibeam satellite ground station antennas employing phased arrays is demonstrated. This linear scan has the potential of reducing the complexity of a narrow-beam planar array to that of a linear array. Calculations for such antennas placed at cities throughout the U.S. show that the peak beam pointing error in covering the 70 deg W to 130 deg W geosynchronous equatorial arc (GEA) is under 5/1000th of a degree. Communication at a 300 MBd rate in the 12/14 GHz band can be made feasible, for a grating lobe-free scan and 0.5 deg beamwidth antenna, by using a relatively simple time equalization.

  1. Role of Indian remote sensing imaging satellites for the Antarctic monitoring and mapping: a case study around Indian Antarctic research stations

    Science.gov (United States)

    Jayaprasad, P.; Mehra, Raghav; Chawla, Saket; Rajak, D. Ram; Oza, Sandip R.

    2016-05-01

    Antarctic research station's existence largely depend on the supply of fuel, food and other commodities through Antarctic Scientific Expedition using ship voyage. Safer Ship Navigation demands high resolution satellite monitoring of the ice conditions which varies from 30 km to 200 km from the Antarctic coast of Research stations. During the last couple of years Indian Satellites play a major role in safer ship navigation in sea ice regions of the Arctic and the Antarctic. Specifically Indian Scientific Expedition to the Antarctica (ISEA) through National Centre for Antarctic and Oceanic Research (NCAOR) is one of the beneficiaries for safer ship navigation using information derived from Indian Satellite data. Space Applications Centre, Indian Space Research Organisation (SAC-ISRO) is providing Sea Ice Advisories for the safer optimum entry and exit for the expedition ship at two of the Research stations Bharati and Maitri. Two of the Indian Satellites namely Radar Imaging Satellite-1 (RISAT-1) and ResourceSAT-2 (RS-2) are the two major workhorses of ISRO for monitoring and mapping of the Antarctic terrain. The present study demonstrate the utilisation potential of these satellite images for various Polar Science Applications. Mosaic of the Antarctic Terrain was generated from RISAT-1 CRS data. The preliminary results of the mosaic from CRS- circular polarisation data is presented. Demonstration of the study is extended for other applications such as change detection studies, safer ship navigation and extreme events of Antarctica. The use of multi resolution multi sensor data is also shown in the study.

  2. UAS Satellite Earth Station Emission Limits for Terrestrial System Interference Protection

    Science.gov (United States)

    Kerczewski, Robert J.; Bishop, William D.

    2017-01-01

    Unmanned aircraft systems (UAS) will have a major impact on future aviation. Medium and large UA operating at altitudes above 3000 feet will require access to non-segregated, that is, controlled airspace. In order for unmanned aircraft to be integrated into the airspace and operate with other commercial aircraft, a very reliable command and control (C2, a. k. a. control and non-payload communications, (CNPC)) link is required. For operations covering large distances or over remote locations, a beyond-line-of-sight (BLOS) CNPC link would need to be implemented through satellite. Significant progress has taken place on several fronts to advance the integration of UAS into controlled airspace, including the recent completion of Minimum Operational Performance Standards (MOPS) for terrestrial line-of-sight (LOS) UAS command and control (C2) links. The development of MOPS for beyond line-of-sight C2 satellite communication links is underway. Meanwhile the allocation of spectrum for UAS C2 by the International Telecommunications Union Radiocommunication Sector (ITU-R) has also progressed. Spectrum for LOS C2 was allocated at the 2012 World Radiocommunication Conference (WRC-12), and for BLOS C2 an allocation was made at WRC-15, under WRC-15 Resolution 155. Resolution 155, however, does not come into effect until several other actions have been completed. One of these required actions is the identification of a power flux density (pfd) limit on the emissions of UAS Ku-Band satellite communications transmitters reaching the ground. The pfd limit is intended to protect terrestrial systems from harmful interference. WRC-19 is expected to finalize the pfd limit. In preparation for WRC-19, analyses of the required pfd limit are on-going, and supporting activities such as propagation modeling are also planned. This paper provides the status of these activities.

  3. Spatial and temporal variation of CO over Alberta using measurements from satellite, aircrafts, and ground stations

    Science.gov (United States)

    Marey, H. S.; Hashisho, Z.; Fu, L.; Gille, J.

    2014-12-01

    Alberta is Canada's largest oil producer and its oil sand deposits comprise 30% of the world's oil reserves. The process of bitumen extraction and upgrading releases trace gases and aerosols to the atmosphere. In this study we present satellite-based analysis to explore, for the first time, various contributing factors that affect tropospheric carbon monoxide (CO) levels over Alberta. The multispectral product that uses both near-infrared (NIR) and the thermal-infrared (TIR) radiances for CO retrieval from the Measurements of Pollution in the Troposphere (MOPITT) are examined for the 12 year period from 2002-2013. Moderate Resolution Imaging Spectroradiometer (MODIS) thermal anomaly product from 2001 to 2013 is employed to investigate the seasonal and temporal variations of forest fires. Additionally, in situ CO measurements at industrial and urban sites are compared to satellite data. Furthermore, the available MOZAIC/IAGOS (Measurement of Ozone, Water Vapor, Carbon Monoxide, Nitrogen Oxide by Airbus In-Service Aircraft/In service Aircraft for Global Observing System) aircraft CO profiles (April 2009-December 2011) are used to validate MOPITT CO data. The climatological time curtain plot and spatial maps for CO over northern Alberta indicate the signatures of transported CO for two distinct biomass burning seasons, summer and spring. Distinct seasonal patterns of CO at the urban site s (Edmonton and Calgary cities) point to the strong influence of traffic. Meteorological parameters play an important role on the CO spatial distribution at various pressure levels. Northern Alberta shows stronger upward lifting motion which leads to larger CO total column values while the poor dispersion in central and south Alberta exacerbates the surface CO pollution. Inter-annual variations of satellite data depict a slightly decreasing trend for both regions while the decline trend is more evident from ground observations, especially at the urban sites. MOPITT CO vertical

  4. Spatial and temporal variation in CO over Alberta using measurements from satellites, aircraft, and ground stations

    Science.gov (United States)

    Marey, H. S.; Hashisho, Z.; Fu, L.; Gille, J.

    2015-04-01

    Alberta is Canada's largest oil producer, and its oil sands deposits comprise 30% of the world's oil reserves. The process of bitumen extraction and upgrading releases trace gases and aerosols to the atmosphere. In this study we present satellite-based analysis to explore, for the first time, various contributing factors that affect tropospheric carbon monoxide (CO) levels over Alberta. The multispectral product that uses both near-infrared (NIR) and the thermal-infrared (TIR) radiances for CO retrieval from the Measurements of Pollution in the Troposphere (MOPITT) is examined for the 12-year period from 2002 to 2013. The Moderate Resolution Imaging Spectroradiometer (MODIS) thermal anomaly product from 2001 to 2013 is employed to investigate the seasonal and temporal variations in forest fires. Additionally, in situ CO measurements at industrial and urban sites are compared to satellite data. Furthermore, the available MOZAIC/IAGOS (Measurement of Ozone, Water Vapor, Carbon Monoxide, Nitrogen Oxide by Airbus In-Service Aircraft/In service Aircraft for Global Observing System) aircraft CO profiles (April 2009-December 2011) are used to validate MOPITT CO data. The climatological time curtain plot and spatial maps for CO over northern Alberta indicate the signatures of transported CO for two distinct biomass burning seasons: summer and spring. Distinct seasonal patterns of CO at the urban sites (Edmonton and Calgary) point to the strong influence of traffic. Meteorological parameters play an important role in the CO spatial distribution at various pressure levels. Northern Alberta shows a stronger upward lifting motion which leads to larger CO total column values, while the poor dispersion in central and southern Alberta exacerbates the surface CO pollution. Interannual variations in satellite data depict a slightly decreasing trend for both regions, while the decline trend is more evident from ground observations, especially at the urban sites. MOPITT CO vertical

  5. Spatial and temporal variation of CO over Alberta using measurements from satellite, aircrafts, and ground stations

    Directory of Open Access Journals (Sweden)

    H. S. Marey

    2014-12-01

    Full Text Available Alberta is Canada's largest oil producer and its oil sand deposits comprise 30% of the world's oil reserves. The process of bitumen extraction and upgrading releases trace gases and aerosols to the atmosphere. In this study we present satellite-based analysis to explore, for the first time, various contributing factors that affect tropospheric carbon monoxide (CO levels over Alberta. The multispectral product that uses both near-infrared (NIR and the thermal-infrared (TIR radiances for CO retrieval from the Measurements of Pollution in the Troposphere (MOPITT are examined for the 12 year period from 2002–2013. Moderate Resolution Imaging Spectroradiometer (MODIS thermal anomaly product from 2001 to 2013 is employed to investigate the seasonal and temporal variations of forest fires. Additionally, in situ CO measurements at industrial and urban sites are compared to satellite data. Furthermore, the available MOZAIC/IAGOS (Measurement of Ozone, Water Vapor, Carbon Monoxide, Nitrogen Oxide by Airbus In-Service Aircraft/In service Aircraft for Global Observing System aircraft CO profiles (April 2009–December 2011 are used to validate MOPITT CO data. The climatological time curtain plot and spatial maps for CO over northern Alberta indicate the signatures of transported CO for two distinct biomass burning seasons, summer and spring. Distinct seasonal patterns of CO at the urban site s (Edmonton and Calgary cities point to the strong influence of traffic. Meteorological parameters play an important role on the CO spatial distribution at various pressure levels. Northern Alberta shows stronger upward lifting motion which leads to larger CO total column values while the poor dispersion in central and south Alberta exacerbates the surface CO pollution. Inter-annual variations of satellite data depict a slightly decreasing trend for both regions while the decline trend is more evident from ground observations, especially at the urban sites. MOPITT CO

  6. Sphingosine-1-phosphate mediates epidermal growth factor-induced muscle satellite cell activation

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Yosuke, E-mail: cynagata@mail.ecc.u-tokyo.ac.jp; Ohashi, Kazuya; Wada, Eiji; Yuasa, Yuki; Shiozuka, Masataka; Nonomura, Yoshiaki; Matsuda, Ryoichi

    2014-08-01

    Skeletal muscle can regenerate repeatedly due to the presence of resident stem cells, called satellite cells. Because satellite cells are usually quiescent, they must be activated before participating in muscle regeneration in response to stimuli such as injury, overloading, and stretch. Although satellite cell activation is a crucial step in muscle regeneration, little is known of the molecular mechanisms controlling this process. Recent work showed that the bioactive lipid sphingosine-1-phosphate (S1P) plays crucial roles in the activation, proliferation, and differentiation of muscle satellite cells. We investigated the role of growth factors in S1P-mediated satellite cell activation. We found that epidermal growth factor (EGF) in combination with insulin induced proliferation of quiescent undifferentiated mouse myoblast C2C12 cells, which are also known as reserve cells, in serum-free conditions. Sphingosine kinase activity increased when reserve cells were stimulated with EGF. Treatment of reserve cells with the D-erythro-N,N-dimethylsphingosine, Sphingosine Kinase Inhibitor, or siRNA duplexes specific for sphingosine kinase 1, suppressed EGF-induced C2C12 activation. We also present the evidence showing the S1P receptor S1P2 is involved in EGF-induced reserve cell activation. Moreover, we demonstrated a combination of insulin and EGF promoted activation of satellite cells on single myofibers in a manner dependent on SPHK and S1P2. Taken together, our observations show that EGF-induced satellite cell activation is mediated by S1P and its receptor. - Highlights: • EGF in combination with insulin induces proliferation of quiescent C2C12 cells. • Sphingosine kinase activity increases when reserve cells are stimulated with EGF. • EGF-induced activation of reserve cells is dependent on sphingosine kinase and ERK. • The S1P receptor S1P2 is involved in EGF-induced reserve cell activation. • EGF-induced reserve cell activation is mediated by S1P and its

  7. Whistler-triggered VLF noise bursts observed on the DE-1 satellite and simultaneously at Antarctic ground stations

    Science.gov (United States)

    Smith, A. J.; Carpenter, D. L.; Inan, U. S.

    1985-01-01

    Simultaneous observations of whistler-triggered very low-frequency noise bursts on the ground at Anarctic stations, Halley and Siple, and on the high-altitude satellite DE-1 are reported. Results of a case study from June 25, 1982 in which the satellite data were recorded near 25 deg south magnetic latitude and the L = 4.7 magnetic shell, are presented. Analysis indicates that the chorus bursts that are triggered in whistler ducts travel downwards in the ducts to low altitudes in the ionosphere, and that propagation to DE-1 is by upward reflection into a nonducted mode. A means of estimating the propagation characteristics of the wave bursts is provided by comparisons of nonducted signals from the Siple transmitter and discrete periodic emissions. The ducted-nonducted mode conversion process is a mechanism for the large-scale spreading into the magnetosphere of coherent whistler-mode wave energy which is generated, amplified, or triggered in small localized ducts. The DE-1 data show that a strong interaction exists between whistler-triggered noise bursts and prevailing hiss levels.

  8. Telecom and scintillation first data analysis for DOMINO: laser communication between SOTA, onboard SOCRATES satellite, and MEO optical ground station

    Science.gov (United States)

    Phung, D.-H.; Samain, E.; Maurice, N.; Albanesse, D.; Mariey, H.; Aimar, M.; M. Lagarde, G.; Artaud, G.; Issler, J.-L.; Vedrenne, N.; Velluet, M.-T.; Toyoshima, M.; Akioka, M.; Kolev, D.; Munemasa, Y.; Takenaka, H.; Iwakiri, N.

    2016-03-01

    In collaboration between CNES, NICT, Geoazur, the first successful lasercom link between the micro-satellite SOCRATES and an OGS in Europe has been established. This paper presents some results of telecom and scintillation first data analysis for 4 successful links in June & July 2015 between SOTA terminal and MEO optical ground station (OGS) at Caussols France. The telecom and scintillation data have been continuously recorded during the passes by using a detector developed at the laboratory. An irradiance of 190 nW/m2 and 430 nW/m2 has been detected for 1549 nm and 976 nm downlinks at 35° elevation. Spectrums of power fluctuation measured at OGS are analyzed at different elevation angles and at different diameters of telescope aperture to determine fluctuations caused by pointing error (due to satellite & OGS telescope vibrations) and caused by atmospheric turbulence. Downlink & Uplink budgets are analyzed, the theoretical estimation matches well to measured power levels. Telecom signal forms and bit error rates (BER) of 1549 nm and 976 nm downlink are also shown at different diameters of telescope aperture. BER is 'Error Free' with full-aperture 1.5m telescope, and almost in `good channel' with 0.4 m sub-aperture of telescope. We also show the comparison between the expected and measured BER distributions.

  9. Global manifestations of a substorm onset observed by a multi-satellite and ground station network

    Directory of Open Access Journals (Sweden)

    H. Wang

    2006-12-01

    Full Text Available With a favorable constellation of spacecraft and ground stations, a study is made on the global manifestations of a substorm onset. The onset occurred simultaneously and conjugately in both hemispheres, confirmed by observations of the auroral breakup from IMAGE FUV-WIC and a sudden intensification of a westward electrojet from ground-based magnetometers. Concurrently with the onset, field-aligned and Hall currents in the auroral ionosphere are observed by CHAMP, which are consistent with the signature of a Harang discontinuity. Immediately after the onset a magnetic field dipolarization is clearly observed by Double Star TC-1, located near the central magnetotail and subsequently, by the Cluster quartet. The observations can be explained by a dawnward propagation of the substorm current wedge at a speed of about 300 km/s.

  10. Cargo transshipment stations as logistic mediators for the fertilizer industry/Estacao de transbordo de cargas como mediador da logistica de fertilizantes

    National Research Council Canada - National Science Library

    Moori, Roberto Giro; Riquetti, Alessandro

    2014-01-01

    ... logistics management absolutely necessary. Accordingly, this article verifies the importance of cargo transshipment stations as mediating variables between integrated logistics management and logistics performance in Brazilian companies that...

  11. Time-transfer experiments between satellite laser ranging ground stations via one-way laser ranging to the Lunar Reconnaissance Orbiter

    Science.gov (United States)

    Mao, D.; Sun, X.; Skillman, D. R.; Mcgarry, J.; Hoffman, E.; Neumann, G. A.; Torrence, M. H.; Smith, D. E.; Zuber, M. T.

    2014-12-01

    Satellite laser ranging (SLR) has long been used to measure the distance from a ground station to an Earth-orbiting satellite in order to determine the spacecraft position in orbit, and to conduct other geodetic measurements such as plate motions. This technique can also be used to transfer time between the station and satellite, and between remote SLR sites, as recently demonstrated by the Time Transfer by Laser Link (T2L2) project by the Centre National d'Etudes Spatiaes (CNES) and Observatorire de la Cote d'Azur (OCA) as well as the Laser Time Transfer (LTT) project by the Shanghai Astronomical Observatory, where two-way and one-way measurements were obtained at the same time. Here we report a new technique to transfer time between distant SLR stations via simultaneous one-way laser ranging (LR) to the Lunar Reconnaissance Orbiter (LRO) spacecraft at lunar distance. The major objectives are to establish accurate ground station times and to improve LRO orbit determination via these measurements. The results of these simultaneous LR measurements are used to compare the SLR station times or transfer time from one to the other using times-of-flight estimated from conventional radio frequency tracking of LRO. The accuracy of the time transfer depends only on the difference of the times-of-flight from each ground station to the spacecraft, and is expected to be at sub-nano second level. The technique has been validated by both a ground-based experiment and an experiment that utilized LRO. Here we present the results to show that sub-nanosecond precision and accuracy are achievable. Both experiments were carried out between the primary LRO-LR station, The Next Generation Satellite Laser Ranging (NGSLR) station, and its nearby station, Mobile Laser System (MOBLAS-7), both at Greenbelt, Maryland. The laser transmit time from both stations were recorded by the same event timer referenced to a Hydrogen maser. The results have been compared to data from a common All

  12. Geostatistical improvements of evapotranspiration spatial information using satellite land surface and weather stations data

    Science.gov (United States)

    de Carvalho Alves, Marcelo; de Carvalho, Luiz Gonsaga; Vianello, Rubens Leite; Sediyama, Gilberto C.; de Oliveira, Marcelo Silva; de Sá Junior, Arionaldo

    2013-07-01

    The objective of the present study was to use the simple cokriging methodology to characterize the spatial variability of Penman-Monteith reference evapotranspiration and Thornthwaite potential evapotranspiration methods based on Moderate Resolution Imaging Spetroradiometer (MODIS) global evapotranspiration products and high-resolution surfaces of WordClim temperature and precipitation data. The climatic element data referred to 39 National Institute of Meteorology climatic stations located in Minas Gerais state, Brazil and surrounding states. The use of geostatistics and simple cokriging technique enabled the characterization of the spatial variability of the evapotranspiration providing uncertainty information on the spatial prediction pattern. Evapotranspiration and precipitation surfaces were implemented for the climatic classification in Minas Gerais. Multivariate geostatistical determined improvements of evapotranspiration spatial information. The regions in the south of Minas Gerais derived from the moisture index estimated with the MODIS evapotranspiration (2000-2010), presented divergence of humid conditions when compared to the moisture index derived from the simple kriged and cokriged evapotranspiration (1961-1990), indicating climate change in this region. There was stronger pattern of crossed covariance between evapotranspiration and precipitation rather than temperature, indicating that trends in precipitation could be one of the main external drivers of the evapotranspiration in Minas Gerais state, Brazil.

  13. Tropospheric ozone variability during the East Asian summer monsoon as observed by satellite (IASI), aircraft (MOZAIC) and ground stations

    Science.gov (United States)

    Safieddine, Sarah; Boynard, Anne; Hao, Nan; Huang, Fuxiang; Wang, Lili; Ji, Dongsheng; Barret, Brice; Ghude, Sachin D.; Coheur, Pierre-François; Hurtmans, Daniel; Clerbaux, Cathy

    2016-08-01

    Satellite measurements from the thermal Infrared Atmospheric Sounding Interferometer (IASI), aircraft data from the MOZAIC/IAGOS project, as well as observations from ground-based stations, are used to assess the tropospheric ozone (O3) variability during the East Asian Summer Monsoon (EASM). Six years 2008-2013 of IASI data analysis reveals the ability of the instrument to detect the onset and the progression of the monsoon seen by a decrease in the tropospheric 0-6 km O3 column due to the EASM, and to reproduce this decrease from one year to the other. The year-to-year variability is found to be mainly dependent on meteorology. Focusing on the period of May-August 2011, taken as an example year, IASI data show clear inverse relationship between tropospheric 0-6 km O3 on one hand and meteorological parameters such as cloud cover, relative humidity and wind speed, on the other hand. Aircraft data from the MOZAIC/IAGOS project for the EASM of 2008-2013 are used to validate the IASI data and to assess the effect of the monsoon on the vertical distribution of the tropospheric O3 at different locations. Results show good agreement with a correlation coefficient of 0.73 (12 %) between the 0-6 km O3 column derived from IASI and aircraft data. IASI captures very well the inter-annual variation of tropospheric O3 observed by the aircraft data over the studied domain. Analysis of vertical profiles of the aircraft data shows a decrease in the tropospheric O3 that is more important in the free troposphere than in the boundary layer and at 10-20° N than elsewhere. Ground station data at different locations in India and China show a spatiotemporal dependence on meteorology during the monsoon, with a decrease up to 22 ppbv in Hyderabad, and up to 5 ppbv in the North China Plain.

  14. Concept for a Lunar Transfer Vehicle for Small Satellite Delivery to the Moon from the International Space Station

    Science.gov (United States)

    Elliott, John; Alkalai, Leon

    2010-01-01

    The International Space Station (ISS) has developed as a very capable center for scientific research in Lower Earth Orbit. An additional potential of the ISS that has not thus far been exploited, is the use of this orbiting plat-form for the assembly and launching of vehicles that could be sent to more distant destinations. This paper reports the results of a recent study that looked at an architecture and conceptual flight system design for a lunar transfer vehicle (LTV) that could be delivered to the ISS in segments, assembled, loaded with payload and launched from the ISS with the objective of delivering multiple small and micro satellites to lunar orbit. The design of the LTV was optimized for low cost and high payload capability, as well as ease of assembly. The resulting design would use solar electric propulsion (SEP) to carry a total payload mass of 250 kg from the ISS to a 100 km lunar orbit. A preliminary concept of operations was developed considering currently available delivery options and ISS capabili-ties that should prove flexible enough to accommodate a variety of payloads and missions. This paper will present an overview of the study, including key trades, mission and flight system design, and notional operational concept.

  15. Studies of Geomagnetic Pulsations Using Magnetometer Data from the CHAMP Low-Earth-Orbit Satellite and Ground-Based Stations: a Review

    Directory of Open Access Journals (Sweden)

    P R Sutcliffe

    2011-06-01

    Full Text Available We review research on geomagnetic pulsations carried out using magnetic field measurements from the CHAMP low-Earth-orbit (LEO satellite and ground-based stations in South Africa and Hungary. The high quality magnetic field measurements from CHAMP made it possible to extract and clearly resolve Pi2 and Pc3 pulsations in LEO satellite data. Our analyses for nighttime Pi2 pulsations are indicative of a cavity mode resonance. However, observations of daytime Pi2 pulsation events identified in ground station data show no convincing evidence of their occurrence in CHAMP data. We also studied low-latitude Pc3 pulsations and found that different types of field line resonant structure occur, namely discrete frequencies driven by a narrow band source and L-dependent frequencies driven by a broad band source.

  16. Low-cost approach for a software-defined radio based ground station receiver for CCSDS standard compliant S-band satellite communications

    Science.gov (United States)

    Boettcher, M. A.; Butt, B. M.; Klinkner, S.

    2016-10-01

    A major concern of a university satellite mission is to download the payload and the telemetry data from a satellite. While the ground station antennas are in general easy and with limited afford to procure, the receiving unit is most certainly not. The flexible and low-cost software-defined radio (SDR) transceiver "BladeRF" is used to receive the QPSK modulated and CCSDS compliant coded data of a satellite in the HAM radio S-band. The control software is based on the Open Source program GNU Radio, which also is used to perform CCSDS post processing of the binary bit stream. The test results show a good performance of the receiving system.

  17. 卫星便携站天线自动对星系统的设计与实现%Design and implement of satellite auto-aiming system on antenna of satellite portable station

    Institute of Scientific and Technical Information of China (English)

    胡明; 王星全; 郑振华; 杨华

    2012-01-01

    In the porcess of narrow-beam portable station antenna aiming the satellite, there are three problems: finding the satellite difficulty, aiming the satellite long-time and low-precision. In this article, an auto-aim instrument on equipment is designed and implemented. This instrument based on PIC singlechip can implement rapid, automatic and precise aiming the satellite by collecting and porcessing the data from GPS and sensors and signal strength module, controling stepping motors to adjust the azimuth and elevation of portable station antenna. Using this system, we can reduce the time, improve the precision in aiming the satellite and prove the efficiency of communication markedly.%针对卫星便携站窄波束天线找星难度大、对星耗时多、对星精度差的问题,设计并实现了一个附加在实装设备上的自动对星工具,以PIC单片机为核心,通过采集和处理GPS数据、方位俯仰传感器数据和卫星信号强度数据,控制高精度步进电机自动调整便携站天线方位角和俯仰角,从而实现快速、自动、精确对星.通过使用高精度步进电机代替传统手工操作,能够明显缩短对星时间、提高对星精度,且体积较小、安装拆卸容易、携带方便,显著提高了通信效能.

  18. Simultaneous Laser Ranging and Communication from an Earth-Based Satellite Laser Ranging Station to the Lunar Reconnaissance Orbiter in Lunar Orbit

    Science.gov (United States)

    Sun, Xiaoli; Skillman, David R.; Hoffman, Evan D.; Mao, Dandan; McGarry, Jan F.; Neumann, Gregory A.; McIntire, Leva; Zellar, Ronald S.; Davidson, Frederic M.; Fong, Wai H.; Krainak, Michael A.; Zuber, Maria T.; Smith, David E.

    2013-01-01

    We report a free space laser communication experiment from the satellite laser ranging (SLR) station at NASA Goddard Space Flight Center (GSFC) to the Lunar Reconnaissance Orbiter (LRO) in lunar orbit through the on board one-way Laser Ranging (LR) receiver. Pseudo random data and sample image files were transmitted to LRO using a 4096-ary pulse position modulation (PPM) signal format. Reed-Solomon forward error correction codes were used to achieve error free data transmission at a moderate coding overhead rate. The signal fading due to the atmosphere effect was measured and the coding gain could be estimated.

  19. Satellite RNA-mediated Reduction of Cucumber Mosaic Virus Genomic RNAs Accumulation in Nicotiana tabacum

    Institute of Scientific and Technical Information of China (English)

    Qiansheng LIAO; Liping ZHU; Zhiyou DU; Rong ZENG; Junli FENG; Jishuang CHEN

    2007-01-01

    Satellite RNAs (satRNAs) are molecular parasites that interfere with the pathogenesis of the helper viruses.In this study,the relative accumulation of cucumber mosaic virus (CMV)-Fny genomic RNAs with or without satRNAs were quantitatively analyzed by real-time RT-PCR.The results showed that satRs apparently attenuated the symptoms of CMV-Fny on Nicotiana tabacum by depressing the accumulation of CMV-Fny genomic RNAs,tested as open reading frames.The accumulation of CMV-Fny la,2a,2b,3a,and CP genes was much higher than that of CMV-Fny with satRs added(CMV-Fsat),at different inoculation times.CMV-Fny△2b,in which the complete 2b gene and 41 amino acids at the C-terminal of the 2a gene were deleted,caused only a slight mosaic effect on N.tabacum seedlings,similar to that of CMVFsat,but the addition of satRs to CMV-Fny△2b showed further decrease in the accumulation of CMVFny△2b genomic RNAs.Our results indicated that the attenuation of CMV,by adding satRs or deleting the 2b gene,was due to the low accumulation of CMV genomic RNAs,and that satRNA-mediated reduction of CMV genomic RNAs accumulation in N.tabacum was possibly related to the 2b gene.

  20. Comparison of satellite-derived land surface temperature and air temperature from meteorological stations on the Pan-Arctic scale

    NARCIS (Netherlands)

    Urban, M.; Eberle, J.; Hüttich, C.; Schmullius, C.; Herold, M.

    2013-01-01

    Satellite-based temperature measurements are an important indicator for global climate change studies over large areas. Records from Moderate Resolution Imaging Spectroradiometer (MODIS), Advanced Very High Resolution Radiometer (AVHRR) and (Advanced) Along Track Scanning Radiometer ((A)ATSR) are pr

  1. High altitude clouds impacts on the design of optical feeder link and optical ground station network for future broadband satellite services

    Science.gov (United States)

    Poulenard, S.; Ruellan, M.; Roy, B.; Riédi, J.; Parol, F.; Rissons, A.

    2014-03-01

    Optical links at 1.55μm are envisaged to cope with the increasing capacity demand from geostationary telecom satellite operators without the need of Radio Frequency (RF) coordination. Due to clouds blockages, site diversity techniques based on a network of Optical Ground Stations (OGS) are necessary to reach the commonly required link availability (e.g. 99.9% over the year). Evaluation of the N Optical Ground Station Network (N-OGSN) availability is based on Clouds Masks (CMs) and depends on the clouds attenuation taken in the optical communication budget link. In particular, low attenuation of high semitransparent clouds (i.e. cirrus) could be incorporated into the budget link at the price of larger or more powerful optical terminals. In this paper, we present a method for the calibration of the attenuation at 1.55 μm of high semitransparent clouds. We perform OGS localization optimization in Europe and we find that the incorporation of thin cirrus attenuation in the budget link reduces by 20% the number of handover (i.e. switches OGS) and the handover rate. It is also shown that the minimum number of station required in Europe to reach 99.9% link availability is 10 to 11. When the zone of research is enlarged the Africa, this number is reduced to 3 to 4.

  2. Hammerhead-mediated processing of satellite pDo500 family transcripts from Dolichopoda cave crickets.

    Science.gov (United States)

    Rojas, A A; Vazquez-Tello, A; Ferbeyre, G; Venanzetti, F; Bachmann, L; Paquin, B; Sbordoni, V; Cedergren, R

    2000-10-15

    This work reports the discovery and functional characterization of catalytically active hammerhead motifs within satellite DNA of the pDo500 family from several DOLICHOPODA: cave cricket species. We show that in vitro transcribed RNA of some members of this satellite DNA family do self-cleave in vitro. This self-cleavage activity is correlated with the efficient in vivo processing of long primary transcripts into monomer-sized RNA. The high sequence conservation of the satellite pDo500 DNA family among genetically isolated DOLICHOPODA: schiavazzii populations, as well as other DOLICHOPODA: species, along with the fact that satellite members are actively transcribed in vivo suggests that the hammerhead-encoding satellite transcripts are under selective pressure, perhaps because they fulfil an important physiological role or function. Remarkably, this is the third example of hammerhead ribozyme structures associated with transcribed repetitive DNA sequences from animals. The possibility that such an association may not be purely coincidental is discussed.

  3. A technique for measurement of earth station antenna G/T by radio stars and Applications Technology Satellites.

    Science.gov (United States)

    Kochevar, H. J.

    1972-01-01

    A new technique has been developed to accurately measure the G/T of a small aperture antenna using geostationary satellites and the well established radio star method. A large aperture antenna having the capability of accurately measuring its G/T by using a radio star of known power density is used to obtain an accurate G/T to use as a reference. The CNR of both the large and small aperture antennas are then measured using an Applications Technology Satellite (ATS). After normalizing the two C/N ratios to the large antenna system noise temperature the G/T or the gain G of the small aperture antenna can then be determined.

  4. A multievent study of broadband electrons observed by the DMSP satellites and their relation to red aurora observed at midlatitude stations

    Science.gov (United States)

    Shiokawa, K.; Meng, C.-I.; Reeves, G. D.; Rich, F. J.; Yumoto, K.

    1997-07-01

    Broadband electrons during magnetic storms are characterized by an unusually intense flux of precipitating electrons in the broadband energy range from 30 eV to 30 keV near the equatorward edge of the auroral oval (47°-66° magnetic latitude). Broadband electrons were first reported by Shiokawa et al. [1996]. In this paper, we report a multievent study of broadband electrons, using particle data obtained by the Defense Meteorological Satellite Program (DMSP) satellites during 23 magnetic storms from January 1989 through May 1992. Twelve broadband electron events are identified. Most of them are observed in the night sector, but some are observed in the morning sector. Particle data for successive polar passes of the DMSP multisatellites are used to show that broadband electrons generally last for less than 30 min and that for some events, they precipitate over a wide range of local times simultaneously. On the basis of a quantitative calculation of optical emissions from electrons in the neutral atmosphere, we conclude that broadband electrons are a possible cause of red auroras observed at midlatitude ground stations. We suggest that broadband electrons are associated with certain substorms during the main phase of magnetic storms. This conjecture comes from observations of H component positive bays and Pi 2 pulsations observed at low-latitude magnetic stations and from magnetic field variations observed at geosynchronous satellites. We conclude that the magnetospheric source of broadband electrons lies within the inner part of the plasma sheet. This conclusion is based on the facts that broadband electrons appear in latitudes where plasma sheet particles were observed before the event and that broadband electrons are observed poleward of the subauroral ion drifts, a position that corresponds to the inner edge of the injected particle layer during storms. High-energy particle data obtained at geosynchronous satellites show that both strong magnetopause

  5. Two-day period fluctuation of PMC occurrence over Syowa Station, Antarctica observed by a ground-based lidar and AIM satellite.

    Science.gov (United States)

    Nakamura, T.; Suzuki, H.; Tsutsumi, M.; Ejiri, M. K.; Tomikawa, Y.; Abo, M.; Kawahara, T.; Tsuda, T. T.; Nishiyama, T.

    2014-12-01

    A Rayleigh/Raman lidar system has been operated by the Japanese Antarctic Research Expedition (JARE) since February, 2011 (JARE 52nd) in Syowa Station Antarctica (69.0S, 39.5E). The lidar system consists of a pulsed Nd:YAG laser (355nm) as a transmitter and two telescopes with four photo multiplier tubes which are to detect Rayleigh scattered light from low and high atmosphere at 355 nm and N2 Raman emission at 387nm. Polar Mesospheric Cloud (PMC) was detected by the lidar at 22:30UT (+3hr for LT) on Feb 4th, 2011, the first day of a routine operation. This event was the first time to detect PMC over Syowa Station by a lidar [Suzuki et al., Ann. Geophys., 2013]. However, signal to noise ratio (SNR) of the PMC event was not so good due to large shot noises from daytime background signals. Moreover, a receiver system was designed mainly for nighttime observations. In this way, observation of PMC during the midnight sun, which also corresponds to most frequent PMC season, was difficult. Thus, to improve SNR of the PMC observation with the lidar during daytime, a narrow band-pass Fabry-Perot etalon unit has been developed and installed in the receiver system on Dec 2013 by JARE 55th. By using this new system, clear PMC signals were successfully detected under daylight condition during the period of summer operation of JARE55th. During this period of 53 days (from 17 Dec. 2013 to 7 Feb. 2014), only 11 days were with a clear sky and suitable for PMC observation. Thus, it was difficult to study temporal variations on a PMC activity only by using the lidar data. Fortunately, NASA's AIM satellite had passed near Syowa Station and provided with complimentary PMC data during observation gap of the lidar. By combining our lidar data with the AIM/CIPS data, nearly continuous monitoring of PMC variability over Syowa Station was achieved for period between 13th and 18th in January 2014. PMC occurrence with an interval of two days over Syowa Station during the period was clearly

  6. Comparison of Satellite-Derived Land Surface Temperature and Air Temperature from Meteorological Stations on the Pan-Arctic Scale

    Directory of Open Access Journals (Sweden)

    Christiane Schmullius

    2013-05-01

    Full Text Available Satellite-based temperature measurements are an important indicator for global climate change studies over large areas. Records from Moderate Resolution Imaging Spectroradiometer (MODIS, Advanced Very High Resolution Radiometer (AVHRR and (Advanced Along Track Scanning Radiometer ((AATSR are providing long-term time series information. Assessing the quality of remote sensing-based temperature measurements provides feedback to the climate modeling community and other users by identifying agreements and discrepancies when compared to temperature records from meteorological stations. This paper presents a comparison of state-of-the-art remote sensing-based land surface temperature data with air temperature measurements from meteorological stations on a pan-arctic scale (north of 60° latitude. Within this study, we compared land surface temperature products from (AATSR, MODIS and AVHRR with an in situ air temperature (Tair database provided by the National Climate Data Center (NCDC. Despite analyzing the whole acquisition time period of each land surface temperature product, we focused on the inter-annual variability comparing land surface temperature (LST and air temperature for the overlapping time period of the remote sensing data (2000–2005. In addition, land cover information was included in the evaluation approach by using GLC2000. MODIS has been identified as having the highest agreement in comparison to air temperature records. The time series of (AATSR is highly variable, whereas inconsistencies in land surface temperature data from AVHRR have been found.

  7. Design of a Free and Open Source Data Processing, Archiving, and Distribution Subsystem for the Ground Receiving Station of the Philippine Scientific Earth Observation Micro-Satellite

    Science.gov (United States)

    Aranas, R. K. D.; Jiao, B. J. D.; Magallon, B. J. P.; Ramos, M. K. F.; Amado, J. A.; Tamondong, A. M.; Tupas, M. E. A.

    2016-06-01

    The Philippines's PHL-Microsat program aims to launch its first earth observation satellite, DIWATA, on the first quarter of 2016. DIWATA's payload consists of a high-precision telescope (HPT), spaceborne multispectral imager (SMI) with liquid crystal tunable filter (LCTF), and a wide field camera (WFC). Once launched, it will provide information about the Philippines, both for disaster and environmental applications. Depending on the need, different remote sensing products will be generated from the microsatellite sensors. This necessitates data processing capability on the ground control segment. Rather than rely on commercial turnkey solutions, the PHL-Microsat team, specifically Project 3:DPAD, opted to design its own ground receiving station data subsystems. This paper describes the design of the data subsystems of the ground receiving station (GRS) for DIWATA. The data subsystems include: data processing subsystem for automatic calibration and georeferencing of raw images as well as the generation of higher level processed data products; data archiving subsystem for storage and backups of both raw and processed data products; and data distribution subsystem for providing a web-based interface and product download facility for the user community. The design covers the conceptual design of the abovementioned subsystems, the free and open source software (FOSS) packages used to implement them, and the challenges encountered in adapting the existing FOSS packages to DIWATA GRS requirements.

  8. DESIGN OF A FREE AND OPEN SOURCE DATA PROCESSING, ARCHIVING, AND DISTRIBUTION SUBSYSTEM FOR THE GROUND RECEIVING STATION OF THE PHILIPPINE SCIENTIFIC EARTH OBSERVATION MICRO-SATELLITE

    Directory of Open Access Journals (Sweden)

    R. K. D. Aranas

    2016-06-01

    Full Text Available The Philippines’s PHL-Microsat program aims to launch its first earth observation satellite, DIWATA, on the first quarter of 2016. DIWATA’s payload consists of a high-precision telescope (HPT, spaceborne multispectral imager (SMI with liquid crystal tunable filter (LCTF, and a wide field camera (WFC. Once launched, it will provide information about the Philippines, both for disaster and environmental applications. Depending on the need, different remote sensing products will be generated from the microsatellite sensors. This necessitates data processing capability on the ground control segment. Rather than rely on commercial turnkey solutions, the PHL-Microsat team, specifically Project 3:DPAD, opted to design its own ground receiving station data subsystems. This paper describes the design of the data subsystems of the ground receiving station (GRS for DIWATA. The data subsystems include: data processing subsystem for automatic calibration and georeferencing of raw images as well as the generation of higher level processed data products; data archiving subsystem for storage and backups of both raw and processed data products; and data distribution subsystem for providing a web-based interface and product download facility for the user community. The design covers the conceptual design of the abovementioned subsystems, the free and open source software (FOSS packages used to implement them, and the challenges encountered in adapting the existing FOSS packages to DIWATA GRS requirements.

  9. Retrieval and satellite intercomparison of O3 measurements from ground-based FTIR Spectrometer at Equatorial Station: Addis Ababa, Ethiopia

    Directory of Open Access Journals (Sweden)

    T. von Clarmann

    2013-02-01

    Full Text Available Since May 2009, high-resolution Fourier Transform Infrared (FTIR solar absorption spectra have been recorded at Addis Ababa (9.01° N latitude, 38.76° E longitude, 2443 m altitude above sea level, Ethiopia. The vertical profiles and total column amounts of ozone (O3 are deduced from the spectra by using the retrieval code PROFFIT (V9.5 and regularly determined instrumental line shape (ILS. A detailed error analysis of the O3 retrieval is performed. Averaging kernels of the target gas shows that the major contribution to the retrieved information comes from the measurement. The degrees of freedom for signals is found to be 2.1 on average for the retrieval of O3 from the observed FTIR spectra. The ozone Volume Mixing Ratio (VMR profiles and column amounts retrieved from FTIR spectra are compared with the coincident satellite observations of Microwave Limb Sounding (MLS, Michelson Interferometer for Passive Atmospheric Sounding (MIPAS, Tropospheric Emission Spectrometer (TES, Ozone Monitoring Instrument (OMI, Atmospheric Infrared Sounding (AIRS and Global Ozone Monitoring Experiment (GOME-2 instruments. The mean relative differences in ozone profiles of FTIR from MLS and MIPAS are generally lower than 15% within the altitude range of 27 to 36 km, whereas difference from TES is lower than 1%. Comparisons of measurements of column amounts from the satellite and the ground-based FTIR show very good agreement as exhibited by relative differences within +0.2% to +2.8% for FTIR versus MLS and GOME-2; and −0.9 to −9.0% for FTIR versus OMI, TES and AIRS. The corresponding standard deviations are within 2.0 to 2.8% for FTIR versus MLS and GOME-2 comparisons whereas that of FTIR versus OMI, TES and AIRS are within 3.5 to 7.3%. Thus, the retrieved O3 VMR and column amounts from a tropical site, Addis Ababa, is found to exhibit very good agreement with all coincident satellite observations over an approximate 3-yr period.

  10. Retrieval and satellite intercomparison of O3 measurements from ground-based FTIR Spectrometer at Equatorial Station: Addis Ababa, Ethiopia

    Science.gov (United States)

    Takele Kenea, S.; Mengistu Tsidu, G.; Blumenstock, T.; Hase, F.; von Clarmann, T.; Stiller, G. P.

    2013-02-01

    Since May 2009, high-resolution Fourier Transform Infrared (FTIR) solar absorption spectra have been recorded at Addis Ababa (9.01° N latitude, 38.76° E longitude, 2443 m altitude above sea level), Ethiopia. The vertical profiles and total column amounts of ozone (O3) are deduced from the spectra by using the retrieval code PROFFIT (V9.5) and regularly determined instrumental line shape (ILS). A detailed error analysis of the O3 retrieval is performed. Averaging kernels of the target gas shows that the major contribution to the retrieved information comes from the measurement. The degrees of freedom for signals is found to be 2.1 on average for the retrieval of O3 from the observed FTIR spectra. The ozone Volume Mixing Ratio (VMR) profiles and column amounts retrieved from FTIR spectra are compared with the coincident satellite observations of Microwave Limb Sounding (MLS), Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), Tropospheric Emission Spectrometer (TES), Ozone Monitoring Instrument (OMI), Atmospheric Infrared Sounding (AIRS) and Global Ozone Monitoring Experiment (GOME-2) instruments. The mean relative differences in ozone profiles of FTIR from MLS and MIPAS are generally lower than 15% within the altitude range of 27 to 36 km, whereas difference from TES is lower than 1%. Comparisons of measurements of column amounts from the satellite and the ground-based FTIR show very good agreement as exhibited by relative differences within +0.2% to +2.8% for FTIR versus MLS and GOME-2; and -0.9 to -9.0% for FTIR versus OMI, TES and AIRS. The corresponding standard deviations are within 2.0 to 2.8% for FTIR versus MLS and GOME-2 comparisons whereas that of FTIR versus OMI, TES and AIRS are within 3.5 to 7.3%. Thus, the retrieved O3 VMR and column amounts from a tropical site, Addis Ababa, is found to exhibit very good agreement with all coincident satellite observations over an approximate 3-yr period.

  11. Seasonal variation of near surface black carbon and satellite derived vertical distribution of aerosols over a semi-arid station in India

    Science.gov (United States)

    Kalluri, Raja Obul Reddy; Gugamsetty, Balakrishnaiah; Kotalo, Rama Gopal; Nagireddy, Siva Kumar Reddy; Tandule, Chakradhar Rao; Thotli, Lokeswara Reddy; Shaik, Nazeer Hussain; Maraka, Vasudeva Reddy; Rajuru, Ramakrishna Reddy; Surendran Nair, Suresh Babu

    2017-02-01

    Extensive measurements of aerosol black carbon mass concentration (BC) and vertical profiles of atmospheric aerosols have been carried out using Aethalometer and CALIPSO level - 2 satellite data from December 2012 to November 2014 over a semi-arid station, Anantapur. We found a bimodal distribution in the mass concentrations of BC aerosols on a diurnal scale. A sharp peak was observed during morning rush hours (7:00 to 8:00 LT) almost an hour after the local sunrise. After which, a broad nocturnal peak was found during 21:00 to 22:00 LT. The seasonal mean BC concentrations (Mixed layer height (ML)) were found to be 3.45 ± 1.44 μg/m3 (676 ± 117 m), 2.55 ± 0.85 μg/m3 (1215 ± 190 m), 1.22 ± 0.31 μg/m3 (1134 ± 194 m) and 1.75 ± 0.70 μg/m3 (612 ± 135 m), during the winter, summer, monsoon and post-monsoon respectively. The vertical profiles of aerosol extinction coefficient and back scattering ratio profiles were derived from Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) showed a strong seasonal variation with aerosols mostly confined below 2 km during the post-monsoon and winter seasons whereas in the other two seasons, the aerosol layer expands beyond 6 km. Depolarization ratios (> 0.2) are higher during summer and monsoon at higher altitude regions demonstrate the presence of dust particles, which contribute to the large aerosol extinction at higher levels. These results are further supported by the backward trajectory cluster analysis.

  12. Hepatocyte Growth Factor-mediated satellite cells niche perturbation promotes development of distinct sarcoma subtypes.

    Science.gov (United States)

    Morena, Deborah; Maestro, Nicola; Bersani, Francesca; Forni, Paolo Emanuele; Lingua, Marcello Francesco; Foglizzo, Valentina; Šćepanović, Petar; Miretti, Silvia; Morotti, Alessandro; Shern, Jack F; Khan, Javed; Ala, Ugo; Provero, Paolo; Sala, Valentina; Crepaldi, Tiziana; Gasparini, Patrizia; Casanova, Michela; Ferrari, Andrea; Sozzi, Gabriella; Chiarle, Roberto; Ponzetto, Carola; Taulli, Riccardo

    2016-03-17

    Embryonal Rhabdomyosarcoma (ERMS) and Undifferentiated Pleomorphic Sarcoma (UPS) are distinct sarcoma subtypes. Here we investigate the relevance of the satellite cell (SC) niche in sarcoma development by using Hepatocyte Growth Factor (HGF) to perturb the niche microenvironment. In a Pax7 wild type background, HGF stimulation mainly causes ERMS that originate from satellite cells following a process of multistep progression. Conversely, in a Pax7 null genotype ERMS incidence drops, while UPS becomes the most frequent subtype. Murine EfRMS display genetic heterogeneity similar to their human counterpart. Altogether, our data demonstrate that selective perturbation of the SC niche results in distinct sarcoma subtypes in a Pax7 lineage-dependent manner, and define a critical role for the Met axis in sarcoma initiation. Finally, our results provide a rationale for the use of combination therapy, tailored on specific amplifications and activated signaling pathways, to minimize resistance emerging from sarcomas heterogeneity.

  13. Point-surface fusion of station measurements and satellite observations for mapping PM2.5 distribution in China: methods and assessment

    CERN Document Server

    Li, Tongwen; Zeng, Chao; Yuan, Qiangqiang; Zhang, Liangpei

    2016-01-01

    Fine particulate matter (PM2.5) is associated with adverse human health effects, and China is currently suffering from serious PM2.5 pollution. To obtain spatially continuous ground-level PM2.5 concentrations, several models established by point-surface fusion of ground station and satellite observations have been developed. However, how well do these models perform at national scale in China? Is there space to improve the estimation accuracy of PM2.5 concentration? The contribution of this study is threefold. Firstly, taking advantage of the newly established national monitoring network, we develop a national-scale generalized regression neural network (GRNN) model to estimate PM2.5 concentrations. Secondly, different assessment experiments are undertaken in time and space, to comprehensively evaluate and compare the performance of the widely used models. Finally, to map the yearly and seasonal mean distribution of PM2.5 concentrations in China, a pixel-based merging strategy is proposed. The results indicat...

  14. Trends in communications satellites

    CERN Document Server

    Curtin, Denis J

    1979-01-01

    Trends in Communications Satellites offers a comprehensive look at trends and advances in satellite communications, including experimental ones such as NASA satellites and those jointly developed by France and Germany. The economic aspects of communications satellites are also examined. This book consists of 16 chapters and begins with a discussion on the fundamentals of electrical communications and their application to space communications, including spacecraft, earth stations, and orbit and wavelength utilization. The next section demonstrates how successful commercial satellite communicati

  15. Point-surface fusion of station measurements and satellite observations for mapping PM2.5 distribution in China: Methods and assessment

    Science.gov (United States)

    Li, Tongwen; Shen, Huanfeng; Zeng, Chao; Yuan, Qiangqiang; Zhang, Liangpei

    2017-03-01

    Fine particulate matter (PM2.5, particulate matters with aerodynamic diameters less than 2.5 μm) is associated with adverse human health effects, and China is currently suffering from serious PM2.5 pollution. To obtain spatially continuous ground-level PM2.5 concentrations, several models established by the point-surface fusion of station measurements and satellite observations have been developed. However, how well do these models perform at national scale in China? Is there space to improve the estimation accuracy of PM2.5 concentration? The contribution of this study is threefold. Firstly, taking advantage of the newly established national monitoring network, we develop a national-scale generalized regression neural network (GRNN) model to estimate PM2.5 concentrations. Secondly, different assessment experiments are undertaken in time and space, to comprehensively evaluate and compare the performance of the widely used models. Finally, to map the yearly and seasonal mean distribution of PM2.5 concentrations in China, a pixel-based merging strategy is proposed. The results indicate that the conventional models (linear regression, multiple linear regression, and semi-empirical model) do not obtain the expected results at national scale, with cross-validation R values of 0.49-0.55 and RMSEs of 30.80-31.51 μg /m3 , respectively. In contrast, the more advanced models (geographically weighted regression, back-propagation neural network, and GRNN) have great advantages in PM2.5 estimation, with R values ranging from 0.61 to 0.82 and RMSEs from 20.93 to 28.68 μg /m3 , respectively. In particular, the proposed GRNN model obtains the best performance. Furthermore, the mapped PM2.5 distribution retrieved from 3-km MODIS aerosol optical depth (AOD) products agrees quite well with the station measurements. The results also show that the approach used in this study has the capacity to provide reasonable information for the global monitoring of PM2.5 pollution in China.

  16. Research on Application Performance of Vehicle-mounted Station of Satellite Mobile Communication%卫星移动通信车载站应用性能研究

    Institute of Scientific and Technical Information of China (English)

    汪洋

    2012-01-01

    在对各类卫星移动通信系统性能分析比较的基础上,从系统造价和可实现程度的角度考虑,同步静止轨道(GEO)系统更适合于区域覆盖卫星移动通信系统,卫星移动通信车载站(简称动中通)是实现地面卫星移动通信系统的关键设备。给出了动中通系统设计中卫星转发器带宽占用率和功率占用率的计算,对动中通站型能力和天线口径的选取进行了分析和讨论,并结合相关计算给出了动中通站型和天线选取的建议。%Based on the system performance comparison among some kinds of satellite mobile communication systems and the consideration of the cost and the extent of realization,the GEO system is more propitious to regional satellite mobile communication system. Vehicle-mounted station of satellite mobile communication is the key device to realize land mobile satellite communication system. The calculation methods of occupancy rates of bandwidth and power of satellite transponder in mobile communication system design are described in this paper. How to choose the size of antenna and the type of the station is analyzed and discussed. Some suggestions are given for choosing antenna and type of the station.

  17. Space station, 1959 to . .

    Science.gov (United States)

    Butler, G. V.

    1981-04-01

    Early space station designs are considered, taking into account Herman Oberth's first space station, the London Daily Mail Study, the first major space station design developed during the moon mission, and the Manned Orbiting Laboratory Program of DOD. Attention is given to Skylab, new space station studies, the Shuttle and Spacelab, communication satellites, solar power satellites, a 30 meter diameter radiometer for geological measurements and agricultural assessments, the mining of the moons, and questions of international cooperation. It is thought to be very probable that there will be very large space stations at some time in the future. However, for the more immediate future a step-by-step development that will start with Spacelab stations of 3-4 men is envisaged.

  18. Skeletal muscle satellite cells: mediators of muscle growth during development and implications for developmental disorders.

    Science.gov (United States)

    Dayanidhi, Sudarshan; Lieber, Richard L

    2014-11-01

    Satellite cells (SCs) are the muscle stem cells responsible for longitudinal and cross-sectional postnatal growth and repair after injury and which provide new myonuclei when needed. We review their morphology and contribution to development and their role in sarcomere and myonuclear addition. SCs, similar to other tissue stem cells, cycle through different states, such as quiescence, activation, and self-renewal, and thus we consider the signaling mechanisms involved in maintenance of these states. The role of the SC niche and their interactions with other cells, such as fibroblasts and the extracellular matrix, are all emerging as major factors that affect aging and disease. Interestingly, children with cerebral palsy appear to have a reduced SC number, which could play a role in their reduced muscular development and even in muscular contracture formation. Finally, we review the current information on SC dysfunction in children with muscular dystrophy and emerging therapies that target promotion of myogenesis and reduction of fibrosis. © 2014 Wiley Periodicals, Inc.

  19. 河北电台大型数字卫星直播车的系统设计%System Design of Large Direct Broadcasting Satellite Car for Hebei Radio Station

    Institute of Scientific and Technical Information of China (English)

    牛晓静

    2013-01-01

      本文较系统地介绍了河北电台大型数字卫星直播车技术系统的设计思路、建设方案以及设计过程中的几项技术创新,为卫星直播车的设计、建设和使用提供了有益的借鉴。%Design ideas, construction programs and some technique innovation of large digital satellite direct broadcasting car for Hebei Radio Station were systematically introduced, which provided beneficial reference for the design, construction and use of satellite direct broadcasting car.

  20. CTCF-mediated reduction of vigilin binding affects the binding of HP1α to the satellite 2 locus.

    Science.gov (United States)

    Shen, Wen-Yan; Liu, Qiu-Ying; Wei, Ling; Yu, Xiao-Qin; Li, Ran; Yang, Wen-Li; Xie, Xiao-Yan; Liu, Wen-Quan; Huang, Yuan; Qin, Yang

    2014-05-02

    CCCTC-binding factor (CTCF) has been implicated in numerous aspects of chromosome biology, and vigilin, a multi-KH-domain protein, participates in heterochromatin formation and chromosome segregation. We previously showed that CTCF interacts with vigilin. Here, we show that human vigilin, but not CTCF, colocalizes with HP1α on heterochromatic satellite 2 and β-satellite repeats. CTCF up-regulates the transcription of satellite 2, while vigilin down-regulates it. Vigilin depletion or CTCF overexpression reduces the binding of HP1α on the satellite 2 locus. Furthermore, overexpression of CTCF resists the loading of vigilin onto the satellite 2 locus. Thus CTCF may regulate vigilin behavior and thus indirectly influence the binding of HP1α to the satellite 2 locus.

  1. 移动通信基站对C波段卫星信号接收的影响%Mobile Communication base Station of C-band Satellite Reception

    Institute of Scientific and Technical Information of China (English)

    李世杰

    2014-01-01

    卫星信号的传输,不可避免地会受到各种电磁波干扰,通过对宁波电视台C波段卫星信号被干扰情况的分析、查找,针对移动通信基站对C波段卫星电视信号的干扰进行分析,并提出解决办法。%Satellite signal transmission is affected inevitably by various kinds of electromagnetic interference . This article proposes a resolution for interference to C-band satellite signal at Ningbo TV station ,which is based on detail analysis on interference by mobile communication base stations .

  2. [Mediator effect analysis of the trait coping style on job stress and fatigue of the military personnel stationed in plateau and high cold region].

    Science.gov (United States)

    Zhang, J J; Jia, J M; Tao, N; Song, Z X; Ge, H; Jiang, Y; Tian, H; Qiu, E C; Tang, J H; Liu, J W

    2017-03-20

    Objective: To investigate the fatigue status of military personnel stationed in plateau and high cold region, and to analyze the mediator effect of trait coping style on job stress and fatigue. Methods: In October 2010, with the method of cluster random sampling survey, 531 military personnel stationed in plateau and high cold region were chosen as subject. The fatigue status were evaluated by the Chinese version multidimensional fatigue inventory (MFI-20) , job stress were evaluated by the Job Stress Survey (JSS) , and trait coping style were evaluated by the Trait Coping Style Questionnaire (TCSQ) . Results: According to the information of different population characteristics, mean rank of physical fatigue about the urban (town) group were higher than that of rural group (Z=-2.200, Pmilitary officers, sergeancy and soldier group (F=18.965, Pmilitary officers, sergeancy and soldier group (F=14.711, P<0.05) . The score of negative coping style were positively correlated with the score of physical fatigue (r(s)=0.129) , reduced activity (r(s)=0.123) , reduced motivation (r(s)=0.149) and general fatigue (r(s)=0.174) respectively, the score of organizational support lack strength were positively correlated with the score of physical fatigue (r(s)=0.090) , reduced activity (r(s)=0.098) , reduced motivation (r(s)=0.099) and general fatigue (r(s)=0.130) respectively. The mediator effect of negative coping style on the job stress and fatigue was 0.013 (P<0.01) . Conclusion: The fatigue statuses of the urban (town) group and the up or equal 20-years old age group are poor, and the negative coping style plays mediator effect on the job stress and fatigue.

  3. 液化天然气(LNG)卫星站设备选型分析%Analysis on Type Selection of Equipments for Satellite Stations of Liquefied Natural Gas

    Institute of Scientific and Technical Information of China (English)

    苏圣钧

    2015-01-01

    The main role of LNG satellite station is storage, gasification and liquefaction of natural gas, and transports natural gas to downstream users. In this paper, the composition and working principle of the main system in LNG satellite station were introduced; type selection of LNG tanker, LNG storage tanks, air temperature vaporizer and the water bath heater was analyzed. At last, the rationality of type selection was verified by an example.%LNG 卫星站主要作用为储存、气化液化天然气,并将气化后的气态天然气输送给下游用户。简单介绍了 LNG 卫星站主要系统组成及其工作原理,对卫星站主要设备 LNG 槽车、LNG 储罐、空温气化器和水浴加热器进行了选型分析,最后通过实例进行验证选型。

  4. Intercomparison of stratospheric nitrogen dioxide columns retrieved from ground-based DOAS and FTIR and satellite DOAS instruments over the subtropical Izana station

    OpenAIRE

    Robles-Gonzalez, Cristina; Navarro-Comas, Mónica; Puentedura, Olga; Schneider, Matthias; Hase, Frank; Garcia, Omaira; Blumenstock, Thomas; Gil-Ojeda, Manuel

    2016-01-01

    A 13-year analysis (2000–2012) of the NO2 vertical column densities derived from ground-based (GB) instruments and satellites has been carried out over the Izaña NDACC (Network for the Detection of the Atmospheric Composition Change) subtropical site. Ground-based DOAS (differential optical absorption spectroscopy) and FTIR (Fourier transform infrared spectroscopy) instruments are intercompared to test mutual consistency and then used for validation of stratospheric NO2 fro...

  5. Business earth stations for telecommunications

    Science.gov (United States)

    Morgan, Walter L.; Rouffet, Denis

    The current status of technology for small commercial satellite-communication earth stations is reviewed on the basis of an application study undertaken in the U.S. and Europe. Chapters are devoted to an overview of satellite communication networks, microterminal design and hardware implementation, microterminal applications, the advantages of microterminals, typical users, services provided, the U.S. market for small earth stations, network operators, and the economics of satellite and terrestrial communication services. Consideration is given to the operation of a microterminal network, standards and regulations, technological factors, space-segment requirements, and insurance aspects. Diagrams, graphs, tables of numerical data, and a glossary of terms are provided.

  6. Mediatization

    DEFF Research Database (Denmark)

    Hjarvard, Stig

    2017-01-01

    Mediatization research shares media effects studies' ambition of answering the difficult questions with regard to whether and how media matter and influence contemporary culture and society. The two approaches nevertheless differ fundamentally in that mediatization research seeks answers...... to these general questions by distinguishing between two concepts: mediation and mediatization. The media effects tradition generally considers the effects of the media to be a result of individuals being exposed to media content, i.e. effects are seen as an outcome of mediated communication. Mediatization...... research is concerned with long-term structural changes involving media, culture, and society, i.e. the influences of the media are understood in relation to how media are implicated in social and cultural changes and how these processes come to create new conditions for human communication and interaction...

  7. Atmosphere Impact and Ground Station Selection for Satellite-to-Ground Laser Communication%星地链路激光通信地面站址选择及大气影响研究

    Institute of Scientific and Technical Information of China (English)

    娄岩; 赵义武; 陈纯毅

    2014-01-01

    综合考虑我国方量的地理分布和气候特点,提出了一项星地激光通信的地面多址布站方案,仿真分析了大气散射引起的衰减及大气湍流对星地链路的影响.利用卫星工具包(STK)软件分析了地球静止轨道(GEO)卫星与5个地面站的链路特性.结果表明,西藏的阿里站同时具有最理想的经度和纬度,地平角为52°,最有利于开展星地激光通信.在一定天气条件下,随着波长的增加,对应的散射引起的功率衰减减小;随着能见度的降低,大气散射引起的光功率平均衰减增加;随着地平角的升高,大气引起的功率平均衰减减小;波长越长,闪烁指数越小;随着接收孔径直径的增大,闪烁指数快速减小;随着海拔高度的增加,闪烁方差减小.该研究为星地激光通信外场实验提供了一定的理论依据.%A multiple ground stations scheme satellite-to-ground laser communication is proposed with the geographical distribution of cloud cover and climatic features considered.The effect of attenuation caused by atmospheric scattering and atmospheric turbulence is analyzed for different paths from geosynchronous earth orbit (GEO) satellites to five ground stations.Link characteristics between the GEO satellite and the five ground stations are simulated using the satellite tool kit (STK) software.The results show that Ali region in Tibet has the best longitude and latitude conditions with a horizontal angle of 52 °,which is most beneficial to laser satelliteto-ground communications.The power attenuation shows a decreasing trend as the wavelength increases due to scattering under the same weather conditions.The optical power attenuation is intensified as visibility falls.The average power attenuation caused by atmosphere decreases along with the rise of horizontal angle.The longer the wavelength λ,the smaller the scintillation index; the scintillation index decreases rapidly when the diameter of receiving aperture

  8. Galileo satellite antenna modeling

    Science.gov (United States)

    Steigenberger, Peter; Dach, Rolf; Prange, Lars; Montenbruck, Oliver

    2015-04-01

    The space segment of the European satellite navigation system Galileo currently consists of six satellites. Four of them belong to the first generation of In-Orbit Validation (IOV) satellites whereas the other two are Full Operational Capability (FOC) satellites. High-precision geodetic applications require detailed knowledge about the actual phase center of the satellite and receiver antenna. The deviation of this actual phase center from a well-defined reference point is described by phase center offsets (PCOs) and phase center variations (PCVs). Unfortunately, no public information is available about the Galileo satellite antenna PCOs and PCVs, neither for the IOV, nor the FOC satellites. Therefore, conventional values for the IOV satellite antenna PCOs have been adopted for the Multi-GNSS experiment (MGEX) of the International GNSS Service (IGS). The effect of the PCVs is currently neglected and no PCOs for the FOC satellites are available yet. To overcome this deficiency in GNSS observation modeling, satellite antenna PCOs and PCVs are estimated for the Galileo IOV satellites based on global GNSS tracking data of the MGEX network and additional stations of the legacy IGS network. Two completely independent solutions are computed with the Bernese and Napeos software packages. The PCO and PCV values of the individual satellites are analyzed and the availability of two different solutions allows for an accuracy assessment. The FOC satellites are built by a different manufacturer and are also equipped with another type of antenna panel compared to the IOV satellites. Signal transmission of the first FOC satellite has started in December 2014 and activation of the second satellite is expected for early 2015. Based on the available observations PCO estimates and, optionally PCVs of the FOC satellites will be presented as well. Finally, the impact of the new antenna model on the precision and accuracy of the Galileo orbit determination is analyzed.

  9. Simulating Global AeroMACS Airport Ground Station Antenna Power Transmission Limits to Avoid Interference With Mobile Satellite Service Feeder Uplinks

    Science.gov (United States)

    Wilson, Jeffrey D.

    2013-01-01

    The Aeronautical Mobile Airport Communications System (AeroMACS), which is based upon the IEEE 802.16e mobile wireless standard, is expected to be implemented in the 5091 to 5150 MHz frequency band. As this band is also occupied by Mobile Satellite Service feeder uplinks, AeroMACS must be designed to avoid interference with this incumbent service. The aspects of AeroMACS operation that present potential interference are under analysis in order to enable the definition of standards that assure that such interference will be avoided. In this study, the cumulative interference power distribution at low Earth orbit from transmitters at global airports was simulated with the Visualyse Professional software. The dependence of the interference power on antenna distribution, gain patterns, duty cycle, and antenna tilt was simulated. As a function of these parameters, the simulation results are presented in terms of the limitations on transmitter power from global airports required to maintain the cumulative interference power under the established threshold.

  10. 星地光通信的天气可用性与地面站选址研究%Satellite-to-ground optical communication's usability with different weathers and ground station location

    Institute of Scientific and Technical Information of China (English)

    姜晓峰; 赵尚弘; 李勇军; 王翔; 李瑞欣

    2012-01-01

    The attenuation of satellite-to-ground optical link in fog, rain, snow and cloud is calculated with empirical formulas. The result of simulation shows the longer the length of the light wave, the smaller the attenuation of the laser in the fog; the attenuation in the snow is 10 -100 times higher than that in the rain; when the optical depth of cloud is 4. 7, the laser attenuation is higher than 20 dB. Considering the geographic distribution, meteorological features and cloud cover statistics, it is suggested that the Tarim basin, the desert of western Inner Mongolia and the northwestern part of Loess Plateau in northwest of China should be favorable for satellite-to-ground optical communication ground station location.%利用经验公式计算了星地光链路在雾、雨、雪、云天气中的衰减,仿真结果表明:波长越长,雾对激光的衰减越小;雪对激光的衰减量高于雨对激光衰减量1~2个数量级;当光学厚度达到4.7时,云层对激光的衰减已达到20 dB以上.综合考虑我国的地理分布和气候特点以及云层覆盖情况,建议我国星地光通信地面站选址可以考虑西北地区的塔里木盆地-内蒙古西部戈壁沙漠-黄土高原西北部一带.

  11. Intercomparison of stratospheric nitrogen dioxide columns retrieved from ground-based DOAS and FTIR and satellite DOAS instruments over the subtropical Izana station

    Science.gov (United States)

    Robles-Gonzalez, Cristina; Navarro-Comas, Mónica; Puentedura, Olga; Schneider, Matthias; Hase, Frank; Garcia, Omaira; Blumenstock, Thomas; Gil-Ojeda, Manuel

    2016-09-01

    A 13-year analysis (2000-2012) of the NO2 vertical column densities derived from ground-based (GB) instruments and satellites has been carried out over the Izaña NDACC (Network for the Detection of the Atmospheric Composition Change) subtropical site. Ground-based DOAS (differential optical absorption spectroscopy) and FTIR (Fourier transform infrared spectroscopy) instruments are intercompared to test mutual consistency and then used for validation of stratospheric NO2 from OMI (Ozone Monitoring Instrument) and SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY). The intercomparison has been carried out taking into account the various differences existing in instruments, namely temporal coincidence, collocation, sensitivity, field of view, etc. The paper highlights the importance of considering an "effective solar zenith angle" instead of the actual one when comparing direct-sun instruments with zenith sky ones for a proper photochemical correction. Results show that NO2 vertical column densities mean relative difference between FTIR and DOAS instruments is 2.8 ± 10.7 % for a.m. data. Both instruments properly reproduce the NO2 seasonal and the interannual variation. Mean relative difference of the stratospheric NO2 derived from OMI and DOAS is -0.2 ± 8.7 % and from OMI and FTIR is -1.6 ± 6.7 %. SCIAMACHY mean relative difference is of 3.7 ± 11.7 and -5.7 ± 11.0 % for DOAS and FTIR, respectively. Note that the days used for the intercomparison are not the same for all the pairs of instruments since it depends on the availability of data. The discrepancies are found to be seasonally dependent with largest differences in winter and excellent agreement in the spring months (AMJ). A preliminary analysis of NO2 trends has been carried out with the available data series. Results show increases in stratospheric NO2 columns in all instruments but larger values in those that are GB than that expected by nitrous oxide oxidation. The

  12. Waste Transfer Stations

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund

    2011-01-01

    tion and transport is usually the most costly part of any waste management system; and when waste is transported over a considerable distance or for a long time, transferring the waste from the collection vehicles to more efficient transportation may be economically beneficial. This involves...... a transfer station where the transfer takes place. These stations may also be accessible by private people, offering flexibility to the waste system, including facilities for bulky waste, household hazardous waste and recyclables. Waste transfer may also take place on the collection route from small...... satellite collection vehicles to large compacting vehicles that cannot effectively travel small streets and alleys within the inner city or in residential communities with narrow roads. However, mobile transfer is not dealt with in this chapter, which focuses on stationary transfer stations. This chapter...

  13. Report of study group 3.3 ''LNG and LPG peak shaving and satellite plants''; Rapport du groupe d'etude 3.3 ''usines d'ecretement de pointes et stations satellites GNL et GPL''

    Energy Technology Data Exchange (ETDEWEB)

    Klein Nagelvoort, R.

    2000-07-01

    This report presents a world-wide overview of LNG and LPG Peak Shaving and Satellite Plants, compiled by the study group 3.3 of the International Gas Union. The scope of the work of the study group includes: - LPG peak shavers (LPG + air, N{sub 2}) in gas distribution networks; - LPG peak shavers for start-up and back-up fuel for LNG terminals and power stations; - LNG peak shavers for gas distribution networks; - Small-scale liquefaction plants for distribution to satellites and dedicated consumers (e.g. power generators, chemical plants, trucking companies etc.); - LNG peak shavers as back-up for large consumers; - Alternative liquefaction technologies for LNG and LPG (e.g. refrigeration cycles, supersonic expansion, thermo-acoustic designs); - Alternative storage tank designs for LNG and LPG. The report presents an overview of current installations world-wide and considers the prospects of technological developments with respect to equipment, remote operations and safety constraints. It also includes where possible a review of capital and operating costs, regulations, and an identification of opportunities and trends. The report collates the information available to the study group at the time of the writing, which may explain some heterogeneity in the document. (author)

  14. Discussion on Time Reduction to Open Vehicular Base Station through Satellite Circuit%关于缩短通过卫星电路开通车载基站时间问题的浅谈

    Institute of Scientific and Technical Information of China (English)

    陈炳

    2015-01-01

    In CDMA emergency safeguard, the delay of vehicular CDMA network base station (BS) opening due to switch-off circuit of temporary scheduling happens more often than not. It degrades enterprise’s image and user’s perception. Based on operational lfow of opening vehicular CDMA network BS through satellite circuit, the main reasons to inlfuence emergency BS opening were discussed to investigate the approach to shortening time to open vehicular BS from aspects of lfow optimization and system construction.%在C网应急保障中,因临时调度的电路不通而延误车载C网基站开通的事情时有发生,给企业形象和用户感知造成一定的不良影响。通过分析经由卫星电路开通车载C网基站的操作全流程,查找到影响应急基站开通的主要原因,现尝试从操作流程优化和制度建设上探索如何缩短开通车载基站时间的办法。

  15. JERS-1 Workshop on the Ground Station for ASEAN

    Science.gov (United States)

    Peanvijarnpong, Chanchai

    1990-11-01

    Presented in viewgraph format, the present status of the ground station and future plan for utilizing earth observation satellites in Thailand is outlined. Topics addressed include: data acquisition system; operation status of LANDSAT, SPOT, and MOS-1 (Marine Observation Satellite-1); remote sensors of satellites; data output form; data correction level; data system in Thailand; ground station for MOS-1 satellite in Thailand; and future plan.

  16. Station Capacity

    DEFF Research Database (Denmark)

    Landex, Alex

    2011-01-01

    Stations are often limiting the capacity of railway networks. This is due to extra need of tracks when trains stand still, trains turning around, and conflicting train routes. Although stations are often the capacity bottlenecks, most capacity analysis methods focus on open line capacity. Therefore......, this paper presents methods to analyze station capacity. Four methods to analyze station capacity are developed. The first method is an adapted UIC 406 capacity method that can be used to analyze switch zones and platform tracks at stations that are not too complex. The second method examines the need...... the probability of conflicts and the minimum headway times into account. The last method analyzes how optimal platform tracks are used by examining the arrival and departure pattern of the trains. The developed methods can either be used separately to analyze specific characteristics of the capacity of a station...

  17. Space Station

    Science.gov (United States)

    Anderton, D. A.

    1985-01-01

    The official start of a bold new space program, essential to maintain the United States' leadership in space was signaled by a Presidential directive to move aggressively again into space by proceeding with the development of a space station. Development concepts for a permanently manned space station are discussed. Reasons for establishing an inhabited space station are given. Cost estimates and timetables are also cited.

  18. Man-made Satellites

    Institute of Scientific and Technical Information of China (English)

    郝昌明

    2005-01-01

    If you watch the sky about an hour after the sun goes down, you may see some “moving stars”. But they're not real stars. They're manmade satellites (卫星). And the biggest of all is the International Space Station (ISS国际空间站).

  19. The Space Station

    Science.gov (United States)

    Sharples, R.; Hieatt, J.

    1984-11-01

    The configuration of the Space Station under design studies by NASA is limited only by the capabilities of the Shuttle and the purposes to which it is applied. Once the standard interlocks, launch vibration modes, and pallet designs are fixed, all other assembly of modular components, testing, and trim will be performed in space. The Station will serve for long-term experiments, as a base for planetary missions asembly, launch, and retrieval, and for loading and launching multiple satellites on an orbital transfer vehicle. Materials processing research will be carried out in the Station, as will various scientific and commercial remote sensing activities. The first operational version (1990) will require four Shuttle launches to reach an assembled mass of 70,000 kg drawing 30 kWe from solar panels and housing a crew of five. By the year 2000 the station will support 10-12 crew members in five habitat modules, will be 31 m long, will have cost $18-20 billion, and will be returning $2 billion per year. The station will be periodically reboosted to higher orbits that decay suficiently for orbiter rendezvous for supplies and assignments.

  20. Satellite Communication.

    Science.gov (United States)

    Technology Teacher, 1985

    1985-01-01

    Presents a discussion of communication satellites: explains the principles of satellite communication, describes examples of how governments and industries are currently applying communication satellites, analyzes issues confronting satellite communication, links mathematics and science to the study of satellite communication, and applies…

  1. A New Approach for Enhanced Communication to LEO Satellites

    NARCIS (Netherlands)

    Gill, E.K.A.; Verhoeven, C.; Gill, K.; De Milliano, M.

    2010-01-01

    Operations of satellites in Low-Earth Orbit (LEO) have been based on exploiting the maximum time of visibility of satellites over their ground stations. In this paper, it is shown that a key parameter for communication between a satellite and a ground station is not the time of visibility but the am

  2. Station Capacity

    DEFF Research Database (Denmark)

    Landex, Alex

    2011-01-01

    Stations are often limiting the capacity of railway networks. This is due to extra need of tracks when trains stand still, trains turning around, and conflicting train routes. Although stations are often the capacity bottlenecks, most capacity analysis methods focus on open line capacity. Therefore......, this paper presents methods to analyze station capacity. Four methods to analyze station capacity are developed. The first method is an adapted UIC 406 capacity method that can be used to analyze switch zones and platform tracks at stations that are not too complex. The second method examines the need...... for platform tracks and the probability that arriving trains will not get a platform track immediately at arrival. The third method is a scalable method that analyzes the conflicts in the switch zone(s). In its simplest stage, the method just analyzes the track layout while the more advanced stages also take...

  3. Structural System Design of Mobile Satellite Communication System Vehicular Station Based on SUV Platform%某SUV平台动中通结构总体设计探讨

    Institute of Scientific and Technical Information of China (English)

    白旭东

    2011-01-01

    介绍了某运动型多功能车(Sport Utility Vehicle,SUV)平台动中通的结构总体设计。针对SUV平台的特点,结合系统使用要求,选择了中轮廓动中通天线和取力发电的供电方式,通过对设备分类布局来提高空间利用率的方法解决了载车空间小、上装设备多的问题。从人机工程的角度探讨了在行驶状态下操作的舒适性,并给出了设备机架的限制高度。阐述了上装设备采取的抗振设计考虑。对系统的整车载荷及行驶稳定性进行了分析计算。在满足系统使用要求的同时保持了原车的优越性能,使载车完整性、安全性、可靠性和舒适性最大化,实现了人机环境的和谐。%This paper introduces the structural system design of a mobile satellite communication system vehicular station based on SUV platform.According to the characteristics of SUV platform and the using requirements of system,medium contour antenna and engine driven generator system are selected.The problem of"many facilities in small space" is well solved through classifying facilities to improve space using efficiency.From the viewpoint of ergonomics,operating comfortableness under running condition is discussed and the height limit of rack is presented.Furthermore,the anti-vibration design of facilities are described,the traveling stability and the load of vehicular station are analyzed and calculated.The design retains the superior performance of SUV while satisfying the system requirements,thus maximizing the integrity,safety,reliability,comfortableness of the vehicle,realizing a harmonious human-machine environment.

  4. 卫星小站远程监控系统通信协议设计与实现%Communication Protocol Design and Realization for the Very Small Aperture Terminal Satellite Station Remote Monitoring System

    Institute of Scientific and Technical Information of China (English)

    贾本凯; 庄卉; 王国平; 郭随平; 陈志禄

    2012-01-01

    For the larger internet delay and higher data packet loss rate of telephone lines, we researched and designed communication protocol for the VSAT satellite station remote monitoring system. We designed 5 categories data frames 46 strips by referencing connection o-riented service serial interface communication protocol system structure and adopting classification first and definition after method. Referencing 802.3 protocol, we designed error retransmission to guarantee the reliability for data frame transmission, by using the data buffer and o-vertime setting. According to the VSAT station parameters actual reading and writing operation, we designed the data frames workflow, make sure the ultimate realization of the system communication protocol design. The test results show that the system communication protocol we designed can ensure system data safe, reliable and correct transmission.%针对电话线路网络延时较大和数据丢包率较高的情况,对VSAT卫星小站远程监控系统通信协议进行了设计研究;借鉴面向连接服务串口通信协议体系结构,采用先分类后定义的方法,设计了5类共46条数据帧;参照802.3协议,利用数据缓冲和超时设置对数据帧可靠性传输进行了出错重传设计;根据VSAT小站参数实际读写操作方式,对数据帧的工作流程进行设计,确保系统通信协议设计的最终实现;测试结果表明:设计的通信协议能够保障系统数据安全可靠正确地传输.

  5. Gaussian Entanglement Distribution via Satellite

    CERN Document Server

    Hosseinidehaj, Nedasadat

    2014-01-01

    In this work we analyse three quantum communication schemes for the generation of Gaussian entanglement between two ground stations. Communication occurs via a satellite over two independent atmospheric fading channels dominated by turbulence-induced beam wander. In our first scheme the engineering complexity remains largely on the ground transceivers, with the satellite acting simply as a reflector. Although the channel state information of the two atmospheric channels remains unknown in this scheme, the Gaussian entanglement generation between the ground stations can still be determined. On the ground, distillation and Gaussification procedures can be applied, leading to a refined Gaussian entanglement generation rate between the ground stations. We compare the rates produced by this first scheme with two competing schemes in which quantum complexity is added to the satellite, thereby illustrating the trade-off between space-based engineering complexity and the rate of ground-station entanglement generation...

  6. Gigabit Satellite Network for NASA's Advanced Communication Technology Satellite (ACTS)

    Science.gov (United States)

    Hoder, Douglas; Bergamo, Marcos

    1996-01-01

    The advanced communication technology satellite (ACTS) gigabit satellite network provides long-haul point-to-point and point-to-multipoint full-duplex SONET services over NASA's ACTS. at rates up to 622 Mbit/s (SONET OC-12), with signal quality comparable to that obtained with terrestrial fiber networks. Data multiplexing over the satellite is accomplished using time-division multiple access (TDMA) techniques coordinated with the switching and beam hopping facilities provided by ACTS. Transmissions through the satellite are protected with Reed-Solomon encoding. providing virtually error-free transmission under most weather conditions. Unique to the system are a TDMA frame structure and satellite synchronization mechanism that allow: (a) very efficient utilization of the satellite capacity: (b) over-the-satellite dosed-loop synchronization of the network in configurations with up to 64 ground stations: and (c) ground station initial acquisition without collisions with existing signalling or data traffic. The user interfaces are compatible with SONET standards, performing the function of conventional SONET multiplexers and. as such. can be: readily integrated with standard SONET fiber-based terrestrial networks. Management of the network is based upon the simple network management protocol (SNMP). and includes an over-the-satellite signalling network and backup terrestrial internet (IP-based) connectivity. A description of the ground stations is also included.

  7. Satellite Laser Ranging Photon-Budget Calculations for a Single Satellite Cornercube Retroreflector: Attitude Control Tolerance

    Science.gov (United States)

    2015-11-01

    UNCLASSIFIED Satellite Laser Ranging Photon-Budget Calculations for a Single Satellite Cornercube Retroreflector: Attitude Control Tolerance Philip C...the SLR station, and the direction of the satellite from the SLR station. The required attitude control tolerance is to within 17◦ of the optimal... attitude control strategy determined in the present work. A pre-launch measurement of the re- flectance (diffraction) pattern of each retroreflector is

  8. P2X7 receptors in satellite glial cells mediate high functional expression of P2X3 receptors in immature dorsal root ganglion neurons

    Directory of Open Access Journals (Sweden)

    Chen Yong

    2012-02-01

    Full Text Available Abstract Background The purinergic P2X3 receptor (P2X3R expressed in the dorsal root ganglion (DRG sensory neuron and the P2X7 receptor (P2X7R expressed in the surrounding satellite glial cell (SGC are two major receptors participating in neuron-SGC communication in adult DRGs. Activation of P2X7Rs was found to tonically reduce the expression of P2X3Rs in DRGs, thus inhibiting the abnormal pain behaviors in adult rats. P2X receptors are also actively involved in sensory signaling in developing rodents. However, very little is known about the developmental change of P2X7Rs in DRGs and the interaction between P2X7Rs and P2X3Rs in those animals. We therefore examined the expression of P2X3Rs and P2X7Rs in postnatal rats and determined if P2X7R-P2X3R control exists in developing rats. Findings We immunostained DRGs of immature rats and found that P2X3Rs were expressed only in neurons and P2X7Rs were expressed only in SGCs. Western blot analyses indicated that P2X3R expression decreased while P2X7R expression increased with the age of rats. Electrophysiological studies showed that the number of DRG neurons responding to the stimulation of the P2XR agonist, α,β-meATP, was higher and the amplitudes of α,β-meATP-induced depolarizations were larger in immature DRG neurons. As a result, P2X3R-mediated flinching responses were much more pronounced in immature rats than those found in adult rats. When we reduced P2X7R expression with P2X7R-siRNA in postnatal and adult rats, P2X3R-mediated flinch responses were greatly enhanced in both rat populations. Conclusions These results show that the P2X7R expression increases as rats age. In addition, P2X7Rs in SGCs exert inhibitory control on the P2X3R expression and function in sensory neurons of immature rats, just as observed in adult rats. Regulation of P2X7R expression is likely an effective way to control P2X3R activity and manage pain relief in infants.

  9. Myogenic-specific ablation of Fgfr1 impairs FGF2-mediated proliferation of satellite cells at the myofiber niche but does not abolish the capacity for muscle regeneration

    Directory of Open Access Journals (Sweden)

    Zipora eYablonka-Reuveni

    2015-05-01

    Full Text Available Skeletal muscle satellite cells (SCs are Pax7+ myogenic stem cells that reside between the basal lamina and the plasmalemma of the myofiber. In mature muscles, SCs are typically quiescent, but can be activated in response to muscle injury. Depending on the magnitude of tissue trauma, SCs may divide minimally to repair subtle damage within individual myofibers or produce a larger progeny pool that forms new myofibers in cases of overt muscle injury. SC transition through proliferation, differentiation and renewal is governed by the molecular blueprint of the cells as well as by the extracellular milieu at the SC niche. In particular, the role of the fibroblast growth factor (FGF family in regulating SCs during growth and aging is well recognized. Of the several FGFs shown to affect SCs, FGF1, FGF2 and FGF6 proteins have been documented in adult skeletal muscle. These prototypic paracrine FGFs transmit their mitogenic effect through the FGFRs, which are transmembrane tyrosine kinase receptors. Using the mouse model, we show here that of the four FGFRs, only Fgfr1 and Fgfr4 are expressed at relatively high levels in quiescent SCs and their proliferating progeny. To further investigate the role of FGFR1 in adult myogenesis, we have employed a genetic (Cre/loxP approach for myogenic-specific (MyoDCre-driven ablation of Fgfr1. Neither muscle histology nor muscle regeneration following cardiotoxin-induced injury were overtly affected in Fgfr1-ablated mice. This suggests that FGFR1 is not obligatory for SC performance in this acute muscle trauma model, where compensatory growth factor/cytokine regulatory cascades may exist. However, the SC mitogenic response to FGF2 is drastically repressed in isolated myofibers prepared from Fgfr1-ablated mice. Collectively, our study indicates that FGFR1 is important for FGF-mediated proliferation of SCs and its mitogenic role is not compensated by FGFR4 that is also highly expressed in SCs.

  10. A new method for determination of satellite orbits by transfer

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The original idea of a new method for determination of satellite orbits by transfer is from Two-Way Satellite Time and Frequency Transfer (TWSTFT). The original method is called "determination of satellite orbit by transfer". The method is not only for determination of satellite orbit but also for the time transfer with high accuracy and precision. The advantage is that the accuracy and the precision for determination of satellite orbit are very high and the new method is favorable for various applications. The combination of various signals disseminated and received forms various modes of satellite orbit determinations. If receivers at stations receive the own station-disseminated signals via a satellite transponder, it forms an orbit determination mode called "receiving the own station-disseminated signals mode". If receivers at all stations receive the signals disseminated from the master station via satellite transponders, it forms an orbit determination mode called "receiving the master station-disseminated signals mode". If all of receivers at stations receive all stations-disseminated signals via satellite transponders, it forms an orbit determination mode called "receiving all stations-disseminated signals mode". Also there are other combinations of signals for satellite orbit determination. For dif- ferent orbit determination modes with different signal combinations, their rigorous formulae of proc- essing are hereby presented in this paper. The accurate and the precise satellite orbit determination for both of the modes, "receiving the own station-disseminated signals mode" and "receiving the master station-disseminated signals mode" is attempted. It shows that the accuracy and precision for both of modes are nearly the same, the ranging accuracy is better than 1 cm, and the observation residuals of satellite orbit determination are better than 9 cm in the observation duration of 1 day.

  11. A new method for determination of satellite orbits by transfer

    Institute of Scientific and Technical Information of China (English)

    LI ZhiGang; YANG XuHai; AI GuoXiang; SI HuLi; QIAO RongChuan; FENG ChuGang

    2009-01-01

    The original idea of a new method for determination of satellite orbits by transfer is from Two-Way Satellite Time and Frequency Transfer (TWSTFT).The original method is called "determination of satellite orbit by transfer".The method is not only for determination of satellite orbit but also for the time transfer with high accuracy and precision.The advantage is that the accuracy and the precision for determination of satellite orbit are very high and the new method is favorable for various applications.The combination of various signals disseminated and received forms various modes of satellite orbit determinations.If receivers at stations receive the own station-disseminated signals via a satellite transponder,it forms an orbit determination mode called "receiving the own station-disseminated signals mode".If receivers at all stations receive the signals disseminated from the master station via satellite transponders,it forms an orbit determination mode called "receiving the master station-disseminated signals mode".If all of receivers at stations receive all stations-disseminated signals via satellite transponders,it forms an orbit determination mode called "receiving all stations-disseminated signals mode".Also there are other combinations of signals for satellite orbit determination.For different orbit determination modes with different signal combinations,their rigorous formulae of processing are hereby presented in this paper.The accurate and the precise satellite orbit determination for both of the modes,"receiving the own station-disseminated signals mode" and "receiving the master station-disseminated signals mode" is attempted.It shows that the accuracy and precision for both of modes are nearly the same,the ranging accuracy is better than 1 cm,and the observation residuals of satellite orbit determination are better than 9 cm in the observation duration of 1 day.

  12. Observation Station

    Science.gov (United States)

    Rutherford, Heather

    2011-01-01

    This article describes how a teacher integrates science observations into the writing center. At the observation station, students explore new items with a science theme and use their notes and questions for class writings every day. Students are exposed to a variety of different topics and motivated to write in different styles all while…

  13. women Contrlbute to Satellite Technology

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    IN the early morning of August 14, 1992, at the Xichang satellite launching center, China Central Television Station was about to do a live, worldwide broadcast on the launching of an Australian communications satellite made by the United States. With the order of the commander, "Ignition," people could watch the white rocket rise, pierce the blue sky and race toward the space with a long flaming tail trailing behind it.

  14. Geostationary satellites collocation

    CERN Document Server

    Li, Hengnian

    2014-01-01

    Geostationary Satellites Collocation aims to find solutions for deploying a safe and reliable collocation control. Focusing on the orbital perturbation analysis, the mathematical foundations for orbit and control of the geostationary satellite are summarized. The mathematical and physical principle of orbital maneuver and collocation strategies for multi geostationary satellites sharing with the same dead band is also stressed. Moreover, the book presents some applications using the above algorithms and mathematical models to help readers master the corrective method for planning station keeping maneuvers. Engineers and scientists in the fields of aerospace technology and space science can benefit from this book. Hengnian Li is the Deputy Director of State Key Laboratory of Astronautic Dynamics, China.

  15. Satellite-Based Sunshine Duration for Europe

    Directory of Open Access Journals (Sweden)

    Bodo Ahrens

    2013-06-01

    Full Text Available In this study, two different methods were applied to derive daily and monthly sunshine duration based on high-resolution satellite products provided by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT Satellite Application Facility on Climate Monitoring using data from Meteosat Second Generation (MSG SEVIRI (Spinning Enhanced Visible and Infrared Imager. The satellite products were either hourly cloud type or hourly surface incoming direct radiation. The satellite sunshine duration estimates were not found to be significantly different using the native 15-minute temporal resolution of SEVIRI. The satellite-based sunshine duration products give additional spatial information over the European continent compared with equivalent in situ-based products. An evaluation of the satellite sunshine duration by product intercomparison and against station measurements was carried out to determine their accuracy. The satellite data were found to be within ±1 h/day compared to high-quality Baseline Surface Radiation Network or surface synoptic observations (SYNOP station measurements. The satellite-based products differ more over the oceans than over land, mainly because of the treatment of fractional clouds in the cloud type-based sunshine duration product. This paper presents the methods used to derive the satellite sunshine duration products and the performance of the different retrievals. The main benefits and disadvantages compared to station-based products are also discussed.

  16. Discussion of the design of satellite-laser measurement stations in the eastern Mediterranean under the geological aspect. Contribution to the earthquake prediction research by the Wegener Group and to NASA's Crustal Dynamics Project

    Science.gov (United States)

    Paluska, A.; Pavoni, N.

    1983-01-01

    Research conducted for determining the location of stations for measuring crustal dynamics and predicting earthquakes is discussed. Procedural aspects, the extraregional kinematic tendencies, and regional tectonic deformation mechanisms are described.

  17. Satellite Upper Air Network (SUAN)

    Science.gov (United States)

    Reale, Tony L.; Thorne, Peter

    2004-10-01

    During the past 20 years of NOAA operational polar satellites, it has become evident that a growing problem concerning their utilization in Climate and also Numerical Weather Prediction (NWP) applications are the systematic errors and uncertainties inherent in the satellite measurements. Similar arguments can be made for global radiosonde observations. These uncertainties are often larger than the sensitive signals and processes, that satellite and radiosonde measurements are designed to reveal, particularly in the realm of climate. Possible strategies to quantify and compensate for these problems include the analysis of satellite overlap data and/or available collocations of satellite and ground truth (radiosonde) observations. However, overlap observations are typically not available except in extreme polar regions and current sampling strategies for compiling collocated radiosonde and satellite observations are insufficient, further compounding the inherent uncertainties in the ground-truth radiosonde data. A Satellite Upper Air Network is proposed to provide reference radiosonde launches coincident with operational polar satellite(s) overpass. The SUAN consist of 36 global radiosonde stations sub-sampled from the Global Upper Air Network (GUAN), and is designed to provide a robust, global sample of collocated radiosonde and satellite observations conducive to the monitoring and validation of satellite and radiosonde observations. The routine operation of such a network in conjunction with operational polar satellites would provide a long-term of performance for critical observations of particular importance for climate. The following report presents a candidate network of 36 upper-air sites that could comprise a SUAN. Their selection along with the mutual benefit across the satellite, radiosonde, climate, numerical weather prediction (NWP) and radiative transfer (RT) model areas are discussed.

  18. Induction studies with satellite data

    DEFF Research Database (Denmark)

    Olsen, Nils

    1999-01-01

    analysis of the geomagnetic field is performed, and the Q-response, which is the transfer function between the internal (induced) and the external (inducing) expansion coefficients is determined for a specific frequency. In the second approach, known as the geomagnetic depth sounding method, the C....... This paper reviews and discusses the possibilities for induction studies using high-precision magnetic measurements from low-altitude satellites. The different methods and various transfer functions are presented, with special emphasis on the differences in analysing data from ground stations and from...... satellites. The results of several induction studies with scalar satellite data (from the POGO satellites) and with vector data (from the Magsat mission) demonstrate the ability to probe the Earth's conductivity from space. However, compared to the results obtained with ground data the satellite results...

  19. Satellite RNAs and Satellite Viruses.

    Science.gov (United States)

    Palukaitis, Peter

    2016-03-01

    Satellite RNAs and satellite viruses are extraviral components that can affect either the pathogenicity, the accumulation, or both of their associated viruses while themselves being dependent on the associated viruses as helper viruses for their infection. Most of these satellite RNAs are noncoding RNAs, and in many cases, have been shown to alter the interaction of their helper viruses with their hosts. In only a few cases have the functions of these satellite RNAs in such interactions been studied in detail. In particular, work on the satellite RNAs of Cucumber mosaic virus and Turnip crinkle virus have provided novel insights into RNAs functioning as noncoding RNAs. These effects are described and potential roles for satellite RNAs in the processes involved in symptom intensification or attenuation are discussed. In most cases, models describing these roles involve some aspect of RNA silencing or its suppression, either directly or indirectly involving the particular satellite RNA.

  20. Centriolar satellites

    DEFF Research Database (Denmark)

    Tollenaere, Maxim A X; Mailand, Niels; Bekker-Jensen, Simon

    2015-01-01

    Centriolar satellites are small, microscopically visible granules that cluster around centrosomes. These structures, which contain numerous proteins directly involved in centrosome maintenance, ciliogenesis, and neurogenesis, have traditionally been viewed as vehicles for protein trafficking...... highlight newly discovered regulatory mechanisms targeting centriolar satellites and their functional status, and we discuss how defects in centriolar satellite components are intimately linked to a wide spectrum of human diseases....

  1. Satellite theory

    Science.gov (United States)

    Kozai, Y.

    1981-04-01

    The dynamical characteristics of the natural satellite of Mars, Jupiter, Saturn, Uranus and Neptune are analyzed on the basis of the solar tidal perturbation factor and the oblateness factor of the primary planet for each satellite. For the inner satellites, for which the value of the solar tidal factor is much smaller than the planetary oblateness factor, it is shown that the eccentricity and inclination of satellite orbits are generally very small and almost constant; several pairs of inner satellites are also found to exhibit commensurable mean motions, or secular accelerations in mean longitude. In the case of the outer satellites, for which solar perturbations are dominant, secular perturbations and long-period perturbations may be derived by the solution of equations of motion reduced to one degree of freedom. The existence of a few satellites, termed intermediary satellites, for which the solar tidal perturbation is on the order of the planetary oblateness factor, is also observed, and the pole of the orbital plane of the satellite is noted to execute a complex motion around the pole of the planet or the orbital plane of the planet.

  2. Testosterone inhibits transforming growth factor-β signaling during myogenic differentiation and proliferation of mouse satellite cells: potential role of follistatin in mediating testosterone action.

    Science.gov (United States)

    Braga, Melissa; Bhasin, Shalender; Jasuja, Ravi; Pervin, Shehla; Singh, Rajan

    2012-03-05

    Testosterone (T) administration is associated with increased satellite cell number and skeletal muscle hypertrophy, although there is considerable heterogeneity in the response of different skeletal muscle groups to T in vivo. We investigated the effects of T on the growth and differentiation of satellite cells isolated from levator ani (LA) and gastrocnemius (gastroc) muscles. T up regulated follistatin (Fst) expression, but down regulated the mRNA and protein expression of a number of genes in the transforming growth factor-beta (TGF-β)-signaling pathway. Inhibition of Fst expression by small interfering RNA (siRNA) inhibited myogenic differentiation and blocked the pro-myogenic effects of T. Treatment of satellite cells with T or Fst up regulated the expression of Pax7 and PCNA, and increased their proliferation. T and Fst blocked TGF-β induced inhibition of growth and myogenic differentiation and down regulated TGF-β-dependent transcriptome in both LA and gastroc cells. We conclude that T stimulation of satellite cell proliferation and myogenic differentiation are associated with up regulation of Fst and inhibition of TGF-β-signaling.

  3. An access alternative for mobile satellite networks

    Science.gov (United States)

    Wu, W. W.

    1988-05-01

    Conceptually, this paper discusses strategies of digital satellite communication networks for a very large number of low density traffic stations. These stations can be either aeronautical, land mobile, or maritime. The techniques can be applied to international, domestic, regional, and special purpose satellite networks. The applications can be commercial, scientific, military, emergency, navigational or educational. The key strategy is the use of a non-orthogonal access method, which tolerates overlapping signals. With n being either time or frequency partitions, and with a single overlapping signal allowed, a low cost mobile satellite system can be designed with n squared (n squared + n + 1) number of terminals.

  4. Multi-mission Satellite Management

    Science.gov (United States)

    Jamilkowski, M. L.; Teter, M. A.; Grant, K. D.; Dougherty, B.; Cochran, S.

    2015-12-01

    NOAA's next-generation environmental satellite, the Joint Polar Satellite System (JPSS) replaces the current Polar-orbiting Operational Environmental Satellites (POES). JPSS satellites carry sensors which collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The first JPSS satellite was launched in 2011 and is currently NOAA's primary operational polar satellite. The JPSS ground system is the Common Ground System (CGS), and provides command, control, and communications (C3) and data processing (DP). A multi-mission system, CGS provides combinations of C3/DP for numerous NASA, NOAA, DoD, and international missions. In preparation for the next JPSS satellite, CGS improved its multi-mission capabilities to enhance mission operations for larger constellations of earth observing satellites with the added benefit of streamlining mission operations for other NOAA missions. CGS's multi-mission capabilities allows management all of assets as a single enterprise, more efficiently using ground resources and personnel and consolidating multiple ground systems into one. Sophisticated scheduling algorithms compare mission priorities and constraints across all ground stations, creating an enterprise schedule optimized to mission needs, which CGS executes to acquire the satellite link, uplink commands, downlink and route data to the operations and data processing facilities, and generate the final products for delivery to downstream users. This paper will illustrate the CGS's ability to manage multiple, enterprise-wide polar orbiting missions by demonstrating resource modeling and tasking, production of enterprise contact schedules for NOAA's Fairbanks ground station (using both standing and ad hoc requests), deconflicting resources due to ground outages, and updating resource allocations through dynamic priority definitions.

  5. Beyond Factionalism? Cultural and Children's Programs on Palestinian Satellite TV

    NARCIS (Netherlands)

    M.O. AlMoghayer (Mohammed)

    2016-01-01

    markdownabstractThis study examines the production of Palestinian satellite television in the contemporary era. The focus is on cultural and children’s programs of two key stations, the Hamas-based Al Aqsa Satellite Channel (ASC) and the Fatah-based Palestine Satellite Channel (PSC). The study inter

  6. Geosynchronous Earth Orbit/Low Earth Orbit Space Object Inspection and Debris Disposal: A Preliminary Analysis Using a Carrier Satellite With Deployable Small Satellites

    OpenAIRE

    Crockett, Derick A.

    2013-01-01

    Detailed observations of geosynchronous satellites from earth are very limited. To better inspect these high altitude satellites, the use of small, refuelable satellites is proposed. The small satellites are stationed on a carrier platform in an orbit near the population of geosynchronous satellites. A carrier platform equipped with deployable, refuelable SmallSats is a viable option to inspect geosynchronous satellites. The propellant requirement to transfer to a targeted geosynchronous sate...

  7. 47 CFR 25.143 - Licensing provisions for the 1.6/2.4 GHz mobile-satellite service and 2 GHz mobile-satellite...

    Science.gov (United States)

    2010-10-01

    ...-satellite service and 2 GHz mobile-satellite service. 25.143 Section 25.143 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses Space Stations § 25.143 Licensing provisions for the 1.6/2.4 GHz mobile-satellite service and 2...

  8. Uplink Power Control For Earth/Satellite/Earth Communication

    Science.gov (United States)

    Chakraborty, Dayamoy

    1994-01-01

    Proposed control subsystem adjusts power radiated by uplink transmitter in Earth station/satellite relay station/ Earth station communication system. Adjustments made to compensate for anticipated changes in attenuation by rain. Raw input is a received downlink beacon singal, amplitude of which affected not only by rain fade but also by scintillation, attenuation in atmospheric gases, and diurnal effects.

  9. Effect of parallactic refraction correction on station height determination

    Science.gov (United States)

    Lerch, F. J.; Huston, H. A.

    1973-01-01

    The effect of omitting the parallactic refraction correction for satellite optical observations in the determination of station coordinates is analyzed for a large satellite data distribution. A significant error effect is seen in station heights. A geodetic satellite data distribution of 23 close earth satellites, containing 30,000 optical observations obtained by 13 principal Baker-Nunn camera sites, is employed. This distribution was used in a preliminary Goddard Earth Model (GEM 1) for the determination of the gravity field of the earth and geocentric tracking station locations. The parallactic refraction correction is modeled as an error on the above satellite data and a least squares adjustment for station locations is obtained for each of the 13 Baker-Nunn sites. Results show an average station height shift of +8 meters with a dispersion of plus or minus 0.7 meters for individual sites. Station latitude and longitude shifts amounted to less than a meter. Similar results are obtained from a theoretical method employing a probability distribution for the satellite optical observations.

  10. Satellite Communications

    CERN Document Server

    Pelton, Joseph N

    2012-01-01

    The field of satellite communications represents the world's largest space industry. Those who are interested in space need to understand the fundamentals of satellite communications, its technology, operation, business, economic, and regulatory aspects. This book explains all this along with key insights into the field's future growth trends and current strategic challenges. Fundamentals of Satellite Communications is a concise book that gives all of the key facts and figures as well as a strategic view of where this dynamic industry is going. Author Joseph N. Pelton, PhD, former Dean of the International Space University and former Director of Strategic Policy at Intelstat, presents a r

  11. Controle social e mediação de conflitos: as delegacias da mulher e a violência doméstica Social control and conflict mediation: women's police stations and domestic violence

    Directory of Open Access Journals (Sweden)

    Maria Teresa Nobre

    2008-12-01

    Full Text Available O artigo discute modos de funcionamento institucional das Delegacias da Mulher e dos Juizados Especiais Criminais no atendimento aos casos de violência doméstica, antes da Lei Maria da Penha, tomando como contraponto a apresentação de uma experiência desenvolvida em uma DEAM do Estado de Sergipe, na qual se implantou, por dois anos, em caráter experimental, um Núcleo de Mediação de Conflitos. O trabalho discute a função social da Polícia e da Justiça, para além da repressão à criminalidade, problematizando, por um lado, os limites das ações penais e, por outro, a aplicação do instrumento jurídico de mediação de conflitos em espaços policiais, voltada ao enfrentamento da violência contra a mulher. Por fim, faz algumas considerações sobre a nova legislação brasileira para o atendimento a mulheres em situação de violência doméstica.The article argues ways of institutional functioning of the Women's Police Stations and the Criminal Special Courts in the attendance to the cases of domestic violence, before the Maria da Penha Law, taking as counterpoint the presentation of an experience developed in one Women's Police Station of Sergipe State, in which was implanted, during two years, in experimental character, a Nucleus of Mediation of Conflicts. The work argues the social function of the Police and of Justice, for beyond the repression to crime, debating, on a hand, the limits of the penal actions, and on the other hand, the application of the legal instrument of mediation of conflicts in police spaces, faced to the confrontation of the violence against the woman. Finally, it makes some appreciations on the new Brazilian legislation for the attendance to the women in situation of domestic violence.

  12. Integration of mobile satellite and cellular systems

    Science.gov (United States)

    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.

  13. Satellite Geomagnetism

    DEFF Research Database (Denmark)

    Olsen, Nils; Stolle, Claudia

    2012-01-01

    Observations of Earth’s magnetic field from space began more than 50 years ago. A continuous monitoring of the field using low Earth orbit (LEO) satellites, however, started only in 1999, and three satellites have taken highprecision measurements of the geomagnetic field during the past decade...... ability to characterize and understand the many sources that contribute to Earth’s magnetic field. In this review, we summarize investigations of Earth’s interior and environment that have been possible through the analysis of high-precision magnetic field observations taken by LEO satellites........ The unprecedented time-space coverage of their data opened revolutionary new possibilities for monitoring, understanding, and exploring Earth’s magnetic field. In the near future, the three-satellite constellation Swarm will ensure continuity of such measurement and provide enhanced possibilities to improve our...

  14. Technology for a quasi-GSO satellite communications system

    OpenAIRE

    Katagi, T.; Yonezawa, R.; Chiba, I.; Urasaki, S.

    1999-01-01

    In this paper, a satellite communications system using a Quasi Geostationary Satellite Orbit (Quasi-GSO) is proposed. A 24-hour period Quasi-GSO system could give high quality communication to high latitude regions with its satellites observed from earth stations having high elevation angles. In this paper, a system concept and a deployable flat antenna with light weight antenna elements are described proposing it to be a good candidate for mobile communications satellite use.

  15. Satellite (Natural)

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    In its most general sense, any celestial object in orbit around a similar larger object. Thus, for example, the Magellanic Clouds are satellite galaxies of our own Milky Way galaxy. Without qualification, the term is used to mean a body in orbit around a planet; an alternative term is moon. The term natural satellite distinguishes these bodies from artificial satellites—spacecraft placed in orbi...

  16. Workload characterization for the space station data communications system

    Science.gov (United States)

    Sevcik, K. C.

    1986-01-01

    NASA plans to launch a permanent manned space station in the early 1990's. The station will be used to support a wide variety of activities involving Earth and space observation, satellite maintenance, scientific experimentation, and commercial manufacturing. The control and monitoring of many of these activities will require extensive computer and communications system support. In order to identify an appropriate computer and communication system for supporting the space station, an attempt to characterize the space station's data communications subsystem workload is currently underway. Some of the special aspects of the workload characterization problem are discussed in connection with the space station, and some possible approaches are presented.

  17. Discussion on the Upgrading of L-band in Traditional Satellite Earth Station(1)%浅析传统卫星通信地球站的L频段升级(一)

    Institute of Scientific and Technical Information of China (English)

    石玉龙

    2014-01-01

    On account of the existing features of network in China United Network Communication Corp Beijing Branch, this paper analyzes the main indicators of satellite communication system, identified the key technical parameters of transmission; carefully studies and compares the performance of major equipments, complies with communication technology trends; considers many factors such as transmission, routing deployment, centralized network, online monitoring; makes plans of upgrading L-band of satellite communication system based on the general principles of cutting the cost, efifciency and energy conservation. Moreover, this paper has already carried out some practical researches. It will pave the way for the future development of satellite services.%本文针对北京联通卫星局现有卫星通信网络特点,分析了与承载业务相关的卫星通信系统主要指标,确定了保障业务正常传送的关键技术参数;细致研究、比较各类主流设备性能,顺应通信技术发展趋势;综合考虑业务传送、路由调配、集中网管、在线监测等各方面因素;立足于降本增效、节能减排的总体原则确定了卫星通信系统L频段升级的实施方案;并对其中相关方面进行了细致研究,为今后卫星业务发展铺平了道路。

  18. 浅析传统卫星通信地球站的L频段升级(二)%Discussion on the Upgrading of L-band in Traditional Satellite Earth Station(2)

    Institute of Scientific and Technical Information of China (English)

    石玉龙

    2014-01-01

    On account of the existing features of network in China United Network Communication Corp Beijing Branch, this paper analyzes the main indicators of satellite communication system, identified the key technical parameters of transmission; carefully studies and compares the performance of major equipments, complies with communication technology trends; considers many factors such as transmission, routing deployment, centralized network, online monitoring; makes plans of upgrading L-band of satellite communication system based on the general principles of cutting the cost, efifciency and energy conservation. Moreover, this paper has already carried out some practical researches. It will pave the way for the future development of satellite services.%本文针对北京联通卫星局现有卫星通信网络特点,分析了与承载业务相关的卫星通信系统主要指标,确定了保障业务正常传送的关键技术参数;细致研究、比较各类主流设备性能,顺应通信技术发展趋势;综合考虑业务传送、路由调配、集中网管、在线监测等各方面因素;立足于降本增效、节能减排的总体原则确定了卫星通信系统L频段升级的实施方案;并对其中相关方面进行了细致研究,为今后卫星业务发展铺平了道路。

  19. Automatic Weather Station (AWS) Lidar

    Science.gov (United States)

    Rall, Jonathan A.R.; Abshire, James B.; Spinhirne, James D.; Smith, David E. (Technical Monitor)

    2000-01-01

    An autonomous, low-power atmospheric lidar instrument is being developed at NASA Goddard Space Flight Center. This compact, portable lidar will operate continuously in a temperature controlled enclosure, charge its own batteries through a combination of a small rugged wind generator and solar panels, and transmit its data from remote locations to ground stations via satellite. A network of these instruments will be established by co-locating them at remote Automatic Weather Station (AWS) sites in Antarctica under the auspices of the National Science Foundation (NSF). The NSF Office of Polar Programs provides support to place the weather stations in remote areas of Antarctica in support of meteorological research and operations. The AWS meteorological data will directly benefit the analysis of the lidar data while a network of ground based atmospheric lidar will provide knowledge regarding the temporal evolution and spatial extent of Type la polar stratospheric clouds (PSC). These clouds play a crucial role in the annual austral springtime destruction of stratospheric ozone over Antarctica, i.e. the ozone hole. In addition, the lidar will monitor and record the general atmospheric conditions (transmission and backscatter) of the overlying atmosphere which will benefit the Geoscience Laser Altimeter System (GLAS). Prototype lidar instruments have been deployed to the Amundsen-Scott South Pole Station (1995-96, 2000) and to an Automated Geophysical Observatory site (AGO 1) in January 1999. We report on data acquired with these instruments, instrument performance, and anticipated performance of the AWS Lidar.

  20. Simultaneous single epoch satellite clock modelling in Global Navigation Satellite Systems

    Science.gov (United States)

    Thongtan, Thayathip

    In order to obtain high quality positions from navigation satellites, range errors have to be identified and either modelled or estimated. This thesis focuses on satellite clock errors, which are needed to be known because satellite clocks are not perfectly synchronised with navigation system time. A new approach, invented at UCL, for the simultaneous estimation, in a single epoch, of all satellite clock offsets within a Global Navigation Satellite System (GNSS) from range data collected at a large number of globally distributed ground stations is presented. The method was originally tested using only data from a limited number of GPS satellites and ground stations. In this work a total of 50 globally distributed stations and the whole GPS constellation are used in order to investigate more fully the capabilities of the method, in terms of both accuracy and reliability. A number of different estimation models have been tested. These include those with different weighting schemes, those with and without tropospheric bias parameters and those that include assumptions regarding prior knowledge of satellite orbits. In all cases conclusions have been drawn based on formal error propagation theory. Accuracy has been assessed largely through the sizes of the predicted satellite clock standard deviations and, in the case of simultaneously estimating satellite positions, their error ellipsoids. Both internal and external reliability have been assessed as these are important contributors to integrity, something that is essential for many practical applications. It has been found that the accuracy and reliability of satellite clock offsets are functions of the number of known ground station clocks and distance from them, quality of orbits and quality of range measurement. Also the introduction of tropospheric zenith delay parameters into the model reduces both accuracy and reliability by amounts depending on satellite elevation angles. (Abstract shortened by UMI.)

  1. LOD First Estimates In 7406 SLR San Juan Argentina Station

    Science.gov (United States)

    Pacheco, A.; Podestá, R.; Yin, Z.; Adarvez, S.; Liu, W.; Zhao, L.; Alvis Rojas, H.; Actis, E.; Quinteros, J.; Alacoria, J.

    2015-10-01

    In this paper we show results derived from satellite observations at the San Juan SLR station of Felix Aguilar Astronomical Observatory (OAFA). The Satellite Laser Ranging (SLR) telescope was installed in early 2006, in accordance with an international cooperation agreement between the San Juan National University (UNSJ) and the Chinese Academy of Sciences (CAS). The SLR has been in successful operation since 2011 using NAOC SLR software for the data processing. This program was designed to calculate satellite orbits and station coordinates, however it was used in this work for the determination of LOD (Length Of Day) time series and Earth Rotation speed.

  2. Heart Monitoring By Satellite

    Science.gov (United States)

    1978-01-01

    The ambulance antenna shown is a specially designed system that allows satellite-relayed two-way communications between a moving emergency vehicle and a hospital emergency room. It is a key component of a demonstration program aimed at showing how emergency medical service can be provided to people in remote rural areas. Satellite communication permits immediate, hospital- guided treatment of heart attacks or other emergencies by ambulance personnel, saving vital time when the scene of the emergency is remote from the hospital. If widely adopted, the system could save tens of thousands of lives annually in the U.S. alone, medical experts say. The problem in conventional communication with rural areas is the fact that radio signals travel in line of sight. They may be blocked by tall buildings, hills and mountains, or even by the curvature of the Earth, so signal range is sharply limited. Microwave relay towers could solve the problem, but a complete network of repeater towers would be extremely expensive. The satellite provides an obstruction-free relay station in space.

  3. Tactical Satellite 3

    Science.gov (United States)

    Davis, T. M.; Straight, S. D.; Lockwook, R. B.

    2008-08-01

    Tactical Satellite 3 is an Air Force Research Laboratory Science and Technology (S&T) initiative that explores the capability and technological maturity of small, low-cost satellites. It features a low cost "plug and play" modular bus and low cost militarily significant payloads - a Raytheon developed Hyperspectral imager and secondary payload data exfiltration provided by the Office of Naval Research. In addition to providing for ongoing innovation and demonstration in this important technology area, these S&T efforts also help mitigate technology risk and establish a potential concept of operations for future acquisitions. The key objectives are rapid launch and on-orbit checkout, theater commanding, and near-real time theater data integration. It will also feature a rapid development of the space vehicle and integrated payload and spacecraft bus by using components and processes developed by the satellite modular bus initiative. Planned for a late summer 2008 launch, the TacSat-3 spacecraft will collect and process images and then downlink processed data using a Common Data Link. An in-theater tactical ground station will have the capability to uplink tasking to spacecraft and will receive full data image. An international program, the United Kingdom Defence Science and Technology Laboratory (DSTL) and Australian Defence Science and Technology Organisation (DSTO) plan to participate in TacSat-3 experiments.

  4. An introduction to optimal satellite range scheduling

    CERN Document Server

    Vázquez Álvarez, Antonio José

    2015-01-01

    The satellite range scheduling (SRS) problem, an important operations research problem in the aerospace industry consisting of allocating tasks among satellites and Earth-bound objects, is examined in this book. SRS principles and solutions are applicable to many areas, including: Satellite communications, where tasks are communication intervals between sets of satellites and ground stations Earth observation, where tasks are observations of spots on the Earth by satellites Sensor scheduling, where tasks are observations of satellites by sensors on the Earth. This self-contained monograph begins with a structured compendium of the problem and moves on to explain the optimal approach to the solution, which includes aspects from graph theory, set theory, game theory and belief networks. This book is accessible to students, professionals and researchers in a variety of fields, including: operations research, optimization, scheduling theory, dynamic programming and game theory. Taking account of the distributed, ...

  5. Master station control and capacity assignment for Italsat network

    Science.gov (United States)

    Morris, Adrian; Sampson, Nicholas; Lopes, Antonino; di Martino, Roberto; Saitto, Antonio

    1990-11-01

    The design approach to developing a network-controller and capacity-assignment software package for the Italsat satellite switched/time division multiple-access (SS/TDMA) network is covered. The network consists of TDMA traffic stations (TS) allowing a full mesh connectivity between all sites; one of the TSs is designated as a control station (CS). The major processing elements of the network, the functions of the master station, and database configurations are discussed, along with TDMA-station control and traffic reconfiguration, the assignment of satellite capacity on demand, and interactions among these network elements. Emphasis is placed on the traffic reconfiguration process, and it is pointed out that the satellite network control processor and the CS overhead burst processor work together to provide the system with the necessary support to operate the network.

  6. Scientific Satellites

    Science.gov (United States)

    1967-01-01

    followed Hale’s into orbit. In 1879, Jules Verne wrote about launching small satellites with a gun possessing a muzzle velocity of 10 000 m/sec (ref. 3...was activated in 1950.11 It was located only a few tens of miles from the spot where Jules Verne had his Baltimore Gun Club fire a manned projectile to...principle, satellites can be launched by a single impulse applied at the Earth’s surface-say, with a large cannon, & la Jules Verne (sec. 8-3). In

  7. Future large broadband switched satellite communications networks

    Science.gov (United States)

    Staelin, D. H.; Harvey, R. R.

    1979-01-01

    Critical technical, market, and policy issues relevant to future large broadband switched satellite networks are summarized. Our market projections for the period 1980 to 2000 are compared. Clusters of switched satellites, in lieu of large platforms, etc., are shown to have significant advantages. Analysis of an optimum terrestrial network architecture suggests the proper densities of ground stations and that link reliabilities 99.99% may entail less than a 10% cost premium for diversity protection at 20/30 GHz. These analyses suggest that system costs increase as the 0.6 power of traffic. Cost estimates for nominal 20/30 GHz satellite and ground facilities suggest optimum system configurations might employ satellites with 285 beams, multiple TDMA bands each carrying 256 Mbps, and 16 ft ground station antennas. A nominal development program is outlined.

  8. A preliminary study on dead geostationary satellite removal

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The collision between satellites IRIDIUM 33 and COSMOS 2251 indicated that the clash of two on-orbit satellites was becoming an inevitable reality. Our calculation with the two-line orbit element by NORAD showed that some two geostationary satellites had approached very close in July 2009. Therefore, more attention should be given to avoid such collisions. This paper analyzes the orbital long-term variation of a dead satellite drifting in the geostationary orbit. Also, the negative effects posed by dead satellites upon the on-orbit operational geostationary satellites are studied. Then the paper proposes a novel idea to launch a satellite sweeper whose purpose is to collect the on-orbit dead satellites and help them de-orbit to a "graveyard". The satellite sweeper consists of a parent satellite and a child satellite. The child satellite collects a dead satellite and transfers it to a higher orbit. The parent satellite stationed in the geostationary orbit is in charge of refueling the child satellite. The strategy of maneuver and rendezvous is presented and a series of formulas are derived. The analysis results show that our method to clean the geostationary orbital zone is practical and fuel-saving. With the help of just a few satellite sweepers, we can gain a clean environment of geostationary orbit environment again.

  9. Improved gravity field and station-coordinate estimates from laser tracking data

    Science.gov (United States)

    Gaposchkin, E. M.

    1976-01-01

    Knowledge of the long-wavelength features of the geopotential and the geocentric coordinates of satellite-tracking stations is significantly improved by the use of precision satellite tracking with lasers. Tracking data on nine satellites are combined with terrestrial gravimetry to obtain a spherical-harmonics representation of the geopotential complete through degree and order 24. Laser tracking data are used to determine the coordinates of tracking stations. This coordinate system is referred to an inertial reference frame by use of camera observations and observations of deep-space probes. Resulting geodetic parameters provide better satellite ephemerides and a reference for analyzing satellite-to-sea-surface altimetry.

  10. Satellite and lunar laser ranging in infrared

    Science.gov (United States)

    Courde, Clement; Torre, Jean-Marie; Samain, Etienne; Martinot-Lagarde, Gregoire; Aimar, Mourad; Albanese, Dominique; Maurice, Nicolas; Mariey, Hervé; Viot, Hervé; Exertier, Pierre; Fienga, Agnes; Viswanathan, Vishnu

    2017-05-01

    We report on the implementation of a new infrared detection at the Grasse lunar laser ranging station and describe how infrared telemetry improves the situation. We present our first results on the lunar reflectors and show that infrared detection permits us to densify the observations and allows measurements during the new and the full moon periods. We also present the benefit obtained on the ranging of Global Navigation Satellite System (GNSS) satellites and on RadioAstron which have a very elliptic orbit.

  11. Astrometry and Geostationary Satellites in Venezuela

    Science.gov (United States)

    Lacruz, E.; Abad, C.

    2015-10-01

    We present the current status and the first results of the astrometric project CIDA - ABAE for tracking geo-stationary satellites. This project aims to determine a preliminary orbit for the Venezuelan satellite VENESAT-1, using astrometric positions obtained from an optical telescope. The results presented here are based on observations from the Luepa space tracking ground station in Venezuela, which were processed using astrometric procedures.

  12. The Omninet mobile satellite system

    Science.gov (United States)

    Salmasi, A.; Curry, W.

    Mobile Satellite System (MSS) design offering relatively low cost voice, data, and position location services to nonmetropolitan areas of North America is proposed. The system provides spectrally efficient multiple access and modulation techniques, and flexible user interconnection to public and private switched networks. Separate UHF and L-band satellites employing two 9.1 m unfurlable antennas each, achieve a 6048 channel capacity and utilize spot beams. Mobile terminals have modular design and employ 5 dBi omnidirectional antennas. Gateway stations (with two 5 m Ku-band antennas) and base stations (with a single 1.8 m Ku-band antenna) transmit terrestrial traffic to the satellite, where traffic is then transponded via an L-band or UHF downlink to mobile users. The Network Management Center uses two 5-m antennas and incorporates the Integrated-Adaptive Mobile Access Protocol to assure demand assignment of satellite capacity. Preliminary implementation of this low-risk system involves a mobile alphanumeric data service employing receive-only terminals at Ku-band projected for 1987, and plans for the launching of L-band receive-only packages as early as 1988.

  13. Benefits Derived From Laser Ranging Measurements for Orbit Determination of the GPS Satellite Orbit

    Science.gov (United States)

    Welch, Bryan W.

    2007-01-01

    While navigation systems for the determination of the orbit of the Global Position System (GPS) have proven to be very effective, the current research is examining methods to lower the error in the GPS satellite ephemerides below their current level. Two GPS satellites that are currently in orbit carry retro-reflectors onboard. One notion to reduce the error in the satellite ephemerides is to utilize the retro-reflectors via laser ranging measurements taken from multiple Earth ground stations. Analysis has been performed to determine the level of reduction in the semi-major axis covariance of the GPS satellites, when laser ranging measurements are supplemented to the radiometric station keeping, which the satellites undergo. Six ground tracking systems are studied to estimate the performance of the satellite. The first system is the baseline current system approach which provides pseudo-range and integrated Doppler measurements from six ground stations. The remaining five ground tracking systems utilize all measurements from the current system and laser ranging measurements from the additional ground stations utilized within those systems. Station locations for the additional ground sites were taken from a listing of laser ranging ground stations from the International Laser Ranging Service. Results show reductions in state covariance estimates when utilizing laser ranging measurements to solve for the satellite s position component of the state vector. Results also show dependency on the number of ground stations providing laser ranging measurements, orientation of the satellite to the ground stations, and the initial covariance of the satellite's state vector.

  14. Spacecraft design project: High latitude communications satellite

    Science.gov (United States)

    Josefson, Carl; Myers, Jack; Cloutier, Mike; Paluszek, Steve; Michael, Gerry; Hunter, Dan; Sakoda, Dan; Walters, Wes; Johnson, Dennis; Bauer, Terry

    1989-01-01

    The spacecraft design project was part of AE-4871, Advanced Spacecraft Design. The project was intended to provide experience in the design of all major components of a satellite. Each member of the class was given primary responsibility for a subsystem or design support function. Support was requested from the Naval Research Laboratory to augment the Naval Postgraduate School faculty. Analysis and design of each subsystem was done to the extent possible within the constraints of an eleven week quarter and the design facilities (hardware and software) available. The project team chose to evaluate the design of a high latitude communications satellite as representative of the design issues and tradeoffs necessary for a wide range of satellites. The High-Latitude Communications Satellite (HILACS) will provide a continuous UHF communications link between stations located north of the region covered by geosynchronous communications satellites, i.e., the area above approximately 60 N latitude. HILACS will also provide a communications link to stations below 60 N via a relay Net Control Station (NCS), which is located with access to both the HILACS and geosynchronous communications satellites. The communications payload will operate only for that portion of the orbit necessary to provide specified coverage.

  15. Monitoring of the orbital position of a geostationary satellite by the spatially separated reception of signals of digital satellite television

    Science.gov (United States)

    Kaliuzny, M. P.; Bushuev, F. I.; Sibiriakova, Ye. S.; Shulga, O. V.; Shakun, L. S.; Bezrukovs, V.; Kulishenko, V. F.; Moskalenko, S. S.; Malynovsky, Ye. V.; Balagura, O. A.

    2017-02-01

    The results of the determination of the geostationary satellite "Eutelsat-13B" orbital position obtained during 2015-2016 years using European stations' network for reception of DVB-S signals from the satellite are presented. The network consists of five stations located in Ukraine and Latvia. The stations are equipped with a radio engineering complex developed by the RI "MAO". The measured parameter is a time difference of arrival (TDOA) of the DVB-S signals to the stations of the network. The errors of TDOA determination and satellite coordinates, obtained using a numerical model of satellite motion, are equal ±2.6 m and ±35 m respectively. Software implementation of the numerical model is taken from the free space dynamics library OREKIT.

  16. Experimental millimeter-wave satellite communications system

    Science.gov (United States)

    Suzuki, Yoshiaki; Shimada, Masaaki; Arimoto, Yoshinori; Shiomi, Tadashi; Kitazume, Susumu

    This paper describes an experimental system of millimeter-wave satellite communications via Japan's Engineering Test Satellite-VI (ETS-VI) and a plan of experiments. Two experimental missions are planned using ETS-VI millimeter-wave (43/38 GHz bands) transponder, considering the millimeter-wave characteristics such as large transmission capacity and possibility to construct a small earth station with a high gain antenna. They are a personal communication system and an inter-satellite communication system. Experimental system including the configuration and the fundamental functions of the onboard transponder and the outline of the experiments are presented.

  17. Handbook on satellite communications and broadcasting

    Science.gov (United States)

    Askinazi, G. B.; Bykov, V. L.; Vodopianov, G. V.; D'Iachkova, M. N.; Kantor, L. Ia.; Model, A. M.; Pokras, A. M.; Timofeev, V. V.; Tsirlin, V. M.; Tsirlin, I. S.

    Principles underlying the design and operation of satellite communications systems (SCSs) are reviewed with emphasis on multiple-access techniques. Particular consideration is given to the quality characteristics of CSCs, the frequency ranges assigned to SCSs, an energy analysis of satellite lines, EMC aspects, and the effective utilization of the geostationary orbit. Also examined are the design of earth-station equipment, waveguides and multiplexing equipment, satellite antennas, reliability issues, the Ekran receiving installation, and Gradient-N and Gruppa multiple-access equipment.

  18. Advanced tracking and data relay satellite system

    Science.gov (United States)

    Stern, Daniel

    1992-01-01

    The purpose of this communication satellite system are as follows: to provide NASA needs for satellite tracking and communications through the year 2012; to maintain and augment the current TDRS system when available satellite resources are expended in the latter part of the decade; to provide the necessary ground upgrade to support the augmented services; and to introduce new technology to reduce the system life cycle cost. It is concluded that no ATDRS spacecraft requirement for new modulation techniques, that data rate of 650 MBps is required, and that Space Station Freedom requirement is for 650 MBps data some time after the year 2000.

  19. The SPOT satellite

    Science.gov (United States)

    Fouquet, J.-P.

    1981-03-01

    The background, objectives and data products of the French SPOT remote sensing satellite system are presented. The system, which was developed starting in 1978 with the subsequent participation of Sweden and Belgium, is based on a standard multimission platform with associated ground control station and a mission-specific payload, which includes two High-Resolution Visible range instruments allowing the acquisition of stereoscopic views from different orbits. Mission objectives include the definition of future remote sensing systems, the compilation of a cartographic and resources data base, the study of species discrimination and production forecasting based on frequent access and off-nadir viewing, the compilation of a stereoscopic data base, and platform and instrument qualification, for possible applications in cartography, geology and agriculture. Standard data products will be available at three levels of preprocessing: radiometric correction only, precision processing for vertical viewing, and cartographic quality processing.

  20. Real-time monitoring of seismic data using satellite telemetry

    Directory of Open Access Journals (Sweden)

    L. Merucci

    1997-06-01

    Full Text Available This article describes the ARGO Satellite Seismic Network (ARGO SSN as a reliable system for monitoring, collection, visualisation and analysis of seismic and geophysical low-frequency data, The satellite digital telemetry system is composed of peripheral geophysical stations, a centraI communications node (master sta- tion located in CentraI Italy, and a data collection and processing centre located at ING (Istituto Nazionale di Geofisica, Rome. The task of the peripheral stations is to digitalise and send via satellite the geophysical data collected by the various sensors to the master station. The master station receives the data and forwards them via satellite to the ING in Rome; it also performs alI the monitoring functions of satellite communications. At the data collection and processing centre of ING, the data are received and analysed in real time, the seismic events are identified and recorded, the low-frequency geophysical data are stored. In addition, the generaI sta- tus of the satellite network and of each peripheral station connected, is monitored. The procedure for analysjs of acquired seismic signals allows the automatic calculation of local magnitude and duration magnitude The communication and data exchange between the seismic networks of Greece, Spain and Italy is the fruit of a recent development in the field of technology of satellite transmission of ARGO SSN (project of European Community "Southern Europe Network for Analysis of Seismic Data"

  1. Fire Stations - 2007

    Data.gov (United States)

    Kansas Data Access and Support Center — Fire Station Locations in Kansas Any location where fire fighters are stationed at or based out of, or where equipment that such personnel use in carrying out their...

  2. Big Game Reporting Stations

    Data.gov (United States)

    Vermont Center for Geographic Information — Point locations of big game reporting stations. Big game reporting stations are places where hunters can legally report harvested deer, bear, or turkey. These are...

  3. Water Level Station History

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Images contain station history information for 175 stations in the National Water Level Observation Network (NWLON). The NWLON is a network of long-term,...

  4. Streamflow Gaging Stations

    Data.gov (United States)

    Department of Homeland Security — This map layer shows selected streamflow gaging stations of the United States, Puerto Rico, and the U.S. Virgin Islands, in 2013. Gaging stations, or gages, measure...

  5. Hammond Bay Biological Station

    Data.gov (United States)

    Federal Laboratory Consortium — Hammond Bay Biological Station (HBBS), located near Millersburg, Michigan, is a field station of the USGS Great Lakes Science Center (GLSC). HBBS was established by...

  6. Fire Stations - 2009

    Data.gov (United States)

    Kansas Data Access and Support Center — Fire Stations in Kansas Any location where fire fighters are stationed or based out of, or where equipment that such personnel use in carrying out their jobs is...

  7. Capacity at Railway Stations

    DEFF Research Database (Denmark)

    Landex, Alex

    2011-01-01

    Stations do have other challenges regarding capacity than open lines as it is here the traffic is dispatched. The UIC 406 capacity method that can be used to analyse the capacity consumption can be exposed in different ways at stations which may lead to different results. Therefore, stations need...... special focus when conducting UIC 406 capacity analyses.This paper describes how the UIC 406 capacity method can be expounded for stations. Commonly for the analyses of the stations it is recommended to include the entire station including the switch zone(s) and all station tracks. By including the switch...... is changed, this paper recommends that the railway lines are not always be divided. In case trains turn around on open (single track) line, the capacity consumption may be too low if a railway line is divided. The same can be the case if only few trains are overtaken at an overtaking station. For dead end...

  8. Weather Radar Stations

    Data.gov (United States)

    Department of Homeland Security — These data represent Next-Generation Radar (NEXRAD) and Terminal Doppler Weather Radar (TDWR) weather radar stations within the US. The NEXRAD radar stations are...

  9. Reference Climatological Stations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Reference Climatological Stations (RCS) network represents the first effort by NOAA to create and maintain a nationwide network of stations located only in areas...

  10. Newport Research Station

    Data.gov (United States)

    Federal Laboratory Consortium — The Newport Research Station is the Center's only ocean-port research facility. This station is located at Oregon State University's Hatfield Marine Science Center,...

  11. Satellite communications for the next generation telecommunication services and networks

    Science.gov (United States)

    Chitre, D. M.

    1991-01-01

    Satellite communications can play an important role in provisioning the next-generation telecommunication services and networks, provided the protocols specifying these services and networks are satellite-compatible and the satellite subnetworks, consisting of earth stations interconnected by the processor and the switch on board the satellite, interwork effectively with the terrestrial networks. The specific parameters and procedures of frame relay and broadband integrated services digital network (B-ISDN) protocols which are impacted by a satellite delay. Congestion and resource management functions for frame relay and B-ISDN are discussed in detail, describing the division of these functions between earth stations and on board the satellite. Specific onboard and ground functions are identified as potential candidates for their implementation via neural network technology.

  12. Data capture and processing. [for Space Station

    Science.gov (United States)

    Lyon, John; Smith, Gene; Carper, Richard

    1987-01-01

    A systems concept developed in response to the specific requirements imposed by the Space Station and affiliated instrumentation is described. Particular attention is given to those subsystems associated with initial data capture, handling, routing, and distribution control for return link data via the Tracking and Data Relay Satellite System. The conceived approach, designated the Customer Data and Operations System, includes a data interface facility and a data handling center whose functions are data capture, demultiplexing and routing, early preprocessing, and ancillary data handling.

  13. Station Climatic Summaries, Asia

    Science.gov (United States)

    1989-07-01

    OCDS) ................................................... 077 BIRJAND 408090 8612 (OCDS) ............................................. ( 381 BUSHEHR...ALL HOURS # 2 1 0 1 0 # 0 # 1 # 1 1 CACECR-IB 080 OPERATIONAL CLIMATIC DATA SUMM ARY STATION: BIRJAND , IRAN STATION #: 408090 ICAO ID...082. L@ OPERATIONAL CLIMATIC DATA SIJ44ARY STATION: BIRJAND , IRAN STATION #: 408090 ICAO ID: OIMB LOCATION: 32054’N, 59016’E ELEVATION (FEET): 4823 LST

  14. 47 CFR 101.145 - Interference to geostationary-satellites.

    Science.gov (United States)

    2010-10-01

    ... in the bands 2655-2690 MHz, 5925-7075 MHz, and 12.7-13.25 GHz on board geostationary-space stations... in these bands on board geostationary space stations. (b) 2655 to 2690 MHz and 5925 to 7075 MHz. No... degrees of the geostationary-satellite orbit, taking into account atmospheric refraction....

  15. Digital, Satellite-Based Aeronautical Communication

    Science.gov (United States)

    Davarian, F.

    1989-01-01

    Satellite system relays communication between aircraft and stations on ground. System offers better coverage with direct communication between air and ground, costs less and makes possible new communication services. Carries both voice and data. Because many data exchanged between aircraft and ground contain safety-related information, probability of bit errors essential.

  16. ACSSB land mobile earth station

    Science.gov (United States)

    Taira, Shinichi; Ikegami, Tetsushi; Suzuki, Ryutaro; Suzuki, Shoichi; Kawahara, Hideki; Tada, Shun-Ichi

    1990-03-01

    This paper describes the performance of the land mobile earth station using the Amplitude Companded Single Sideband (ACSSB) modulation technique developed for mobile satellite communications and results of the field experiments which were conducted in rural, suburban, and urban areas. This ACSSB system uses a 3-kHz pilot tone, and the voice frequency band is from 300 to 2500 Hz. The experiments show that the required C/N0 for voice communications is 40 dBHz and the required C/N0 for pilot signal tracking is 34 dBHz. Voice quality in rural and suburban areas was degraded slightly. In urban areas shadowings due to the presence of large buildings and trees caused signal losses. A comparison of the ACSSB system with the conventional narrow-band frequency-modulation system indicates that the ACSSB system can transmit voice signals more efficiently.

  17. A Review on Inter-satellite Link in Inter-satellite Optical Wireless Communication

    Science.gov (United States)

    Arora, Heena; Goyal, Rakesh

    2017-06-01

    In this paper, inter-satellite optical wireless communication (IsOWC) system is proposed, one of the imperative utilizations of free space optics/wireless space optics (FSO)/WSO innovation. IsOWC frameworks give a high bandwidth, small size, small weight, low power and minimal effort different option for present microwave satellite frameworks. Optical communications systems have evolved from lengthy fibers to powerful wireless system. This has hence resulted in the use of optical wireless communication system in space communications. As the quantity of satellites circling the Earth expands year by year, a system between the satellites gives a strategy to them to correspond with one another. This is vital for satellites to send data to each other furthermore to hand off the data starting with one satellite then onto the next satellite and after that to the ground stations. By utilizing laser satellite correspondence, the satellites can be joined with information rates up to a few Gbps. The system performance including bit rates, input power, wavelength and distance on an inter-satellite link was analyzed. Various issues such as bit rates, input power, wavelength and distance were presented in IsOWC.

  18. A MEO Tracking and Data Relay Satellite System Constellation Scheme for China

    Institute of Scientific and Technical Information of China (English)

    WU Ting-yong; WU Shi-qi; LING Xiang

    2005-01-01

    A medium earth orbit (MEO) tracking and data relay satellite system (TDRSS) constellation scheme for China is proposed. This system consists of MEO satellite constellation, inter-satellite links (ISLs) and terrestrial gateway station, which can provide continuous bidirectional data transmission links between low altitude spacecrafts and the terrestrial gateway station in China. Theoretical analysis and simulation results indicate that the proposed constellation can cover the global low altitude space sphere and earth surface of China continuously, and has a preferable practical perspective.

  19. Permanent GNSS Observations at Agh-Ust Satellite Observatory

    Science.gov (United States)

    Kudrys, Jacek

    2016-06-01

    GPS satellite observations at the Faculty of Mining Surveying and Environmental Engineering AGH-UST are conducted since the early 90s of the last century. In 2001, efforts have been made on getting permanently functioning GPS station. At present, observatory is EPN operational center for two GNSS stations KRAW and KRA1. Moreover, KRA1 station is one of fundamental control points in polish horizontal network. The article gives the history and scope of the research carried out in the satellite observatory AGH-UST during the period 2001 - 2015.

  20. Engineering Test Satellite VI (ETS-VI)

    Science.gov (United States)

    Horii, M.; Funakawa, K.

    1991-01-01

    The Engineering Test Satellite-VI (ETS-VI) is being developed as the third Japanese three-axis stabilized engineering test satellite to establish the 2-ton geostationary operational satellite bus system and to demonstrate the high performance satellite communication technology for future operational satellites. The satellite is expected to be stationed at 154 deg east latitude. It will be launched from the Tanegashima Space Center in Japan by a type H-II launch vehicle. The Deep Space Network (DSN) will support the prelaunch compatibility test, data interface verification testing, and launch rehersals. The DSN primary support period is from launch through the final AEF plus 1 hour. Contingency support is from final AEF plus 1 hour until launch plus 1 month. The coverage will consist of all the 26-m antennas as prime and the 34-m antennas at Madrid and Canberra as backup. Maximum support will consist of two 8-hour tracks per station for a 7-day period, plus the contingency support, if required. Information is given in tabular form for DSN support, telemetry, command, and tracking support responsibility.

  1. Non-Coop Station History

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Station history documentation for stations outside the US Cooperative Observer network. Primarily National Weather Service stations assigned WBAN station IDs. Other...

  2. Geostationary Satellite (GOES) Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Visible and Infrared satellite imagery taken from radiometer instruments on SMS (ATS) and GOES satellites in geostationary orbit. These satellites produced...

  3. Neptune's small satellites

    Science.gov (United States)

    Thomas, P.

    1992-04-01

    The small satellites of Neptune and other planets discovered during the Voyager 2 mission are discussed in terms of their composition and relationship to the planetary systems. The satellite Proteus is described in terms of its orbit, five other satellites are described, and they are compared to ther small satellites and systems. Neptune's satellites are hypothesized to be related to the ring system, and the satellite Galatea is related to the confinement of the rings.

  4. Cooperative Station History Forms

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Various forms, photographs and correspondence documenting the history of Cooperative station instrumentation, location changes, inspections, and...

  5. Amtrak Rail Stations (National)

    Data.gov (United States)

    Department of Transportation — Updated database of the Federal Railroad Administration's (FRA) Amtrak Station database. This database is a geographic data set containing Amtrak intercity railroad...

  6. A figure of merit for competing communications satellite designs

    Science.gov (United States)

    Lovell, R. R.; Fordyce, S. W.

    1983-01-01

    Trends in launch schedules, weights, power, and space segment costs per transponder year for Intelsats and North American domsats (domestic communications satellites) are discussed. The Intelsat system currently services 25,000 point to point telephone links at any one moment, and a $3 billion order has been placed for Intelsat VIs, which feature 36,000 telephone circuits each. The Intelsat VI spacecraft will weigh 1670 kg in orbit, a continuance of the trend to heavier satellites, while the domsats will stay at 650 kg due to launch vehicle limitations. Direct television broadcast satellites are being designed for receive only (R/O) earth stations, with each satellite capable of servicing 50,000 individual ground stations. Competition is growing for C and Ku band satellite transponders for DBS, with costs $350,000 each. No standardized design has yet emerged.

  7. Global satellite composites - 20 years of evolution

    Science.gov (United States)

    Kohrs, Richard A.; Lazzara, Matthew A.; Robaidek, Jerrold O.; Santek, David A.; Knuth, Shelley L.

    2014-01-01

    For two decades, the University of Wisconsin Space Science and Engineering Center (SSEC) and the Antarctic Meteorological Research Center (AMRC) have been creating global, regional and hemispheric satellite composites. These composites have proven useful in research, operational forecasting, commercial applications and educational outreach. Using the Man computer Interactive Data System (McIDAS) software developed at SSEC, infrared window composites were created by combining Geostationary Operational Environmental Satellite (GOES), and polar orbiting data from the SSEC Data Center and polar data acquired at McMurdo and Palmer stations, Antarctica. Increased computer processing speed has allowed for more advanced algorithms to address the decision making process for co-located pixels. The algorithms have evolved from a simplistic maximum brightness temperature to those that account for distance from the sub-satellite point, parallax displacement, pixel time and resolution. The composites are the state-of-the-art means for merging/mosaicking satellite imagery.

  8. Satellite Cell Heterogeneity in Skeletal Muscle Homeostasis.

    Science.gov (United States)

    Tierney, Matthew T; Sacco, Alessandra

    2016-06-01

    The cellular turnover required for skeletal muscle maintenance and repair is mediated by resident stem cells, also termed satellite cells. Satellite cells normally reside in a quiescent state, intermittently entering the cell cycle to fuse with neighboring myofibers and replenish the stem cell pool. However, the mechanisms by which satellite cells maintain the precise balance between self-renewal and differentiation necessary for long-term homeostasis remain unclear. Recent work has supported a previously unappreciated heterogeneity in the satellite cell compartment that may underlie the observed variability in cell fate and function. In this review, we examine the work supporting this notion as well as the potential governing principles, developmental origins, and principal determinants of satellite cell heterogeneity.

  9. Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2016 April-July

    Science.gov (United States)

    Warner, Brian D.

    2016-10-01

    Lightcurves for 31 near-Earth asteroids (NEAs), obtained at the Center for Solar System Studies-Palmer Divide Station (CS3-PDS) from 2016 April-July, were analyzed for rotation period and signs of satellites or tumbling.

  10. Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2016 October-December

    Science.gov (United States)

    Warner, Brian D.

    2017-04-01

    Lightcurves for 33 near-Earth asteroids (NEAs) obtained at the Center for Solar System Studies-Palmer Divide Station (CS3-PDS) from 2016 October through December were analyzed for rotation period and signs of satellites or tumbling.

  11. Visibility conflict resolution for multiple antennae and multi-satellites via genetic algorithm

    Science.gov (United States)

    Lee, Junghyun; Hyun, Chung; Ahn, Hyosung; Wang, Semyung; Choi, Sujin; Jung, Okchul; Chung, Daewon; Ko, Kwanghee

    Satellite mission control systems typically are operated by scheduling missions to the visibility between ground stations and satellites. The communication for the mission is achieved by interacting with satellite visibility and ground station support. Specifically, the satellite forms a cone-type visibility passing over a ground station, and the antennas of ground stations support the satellite. When two or more satellites pass by at the same time or consecutively, the satellites may generate a visibility conflict. As the number of satellites increases, solving visibility conflict becomes important issue. In this study, we propose a visibility conflict resolution algorithm of multi-satellites by using a genetic algorithm (GA). The problem is converted to scheduling optimization modeling. The visibility of satellites and the supports of antennas are considered as tasks and resources individually. The visibility of satellites is allocated to the total support time of antennas as much as possible for users to obtain the maximum benefit. We focus on a genetic algorithm approach because the problem is complex and not defined explicitly. The genetic algorithm can be applied to such a complex model since it only needs an objective function and can approach a global optimum. However, the mathematical proof of global optimality for the genetic algorithm is very challenging. Therefore, we apply a greedy algorithm and show that our genetic approach is reasonable by comparing with the performance of greedy algorithm application.

  12. Secure base stations

    NARCIS (Netherlands)

    Bosch, Peter; Brusilovsky, Alec; McLellan, Rae; Mullender, Sape; Polakos, Paul

    2009-01-01

    With the introduction of the third generation (3G) Universal Mobile Telecommunications System (UMTS) base station router (BSR) and fourth generation (4G) base stations, such as the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) Evolved Node B (eNB), it has become important to se

  13. SPS rectifier stations

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    The first of the twelves SPS rectifier stations for the bending magnets arrived at CERN at the end of the year. The photograph shows a station with the rectifiers on the left and in the other three cubicles the chokes, capacitors and resistor of the passive filter.

  14. "Inventive" Learning Stations

    Science.gov (United States)

    Jarrett, Olga

    2010-01-01

    Learning stations can be used for myriad purposes--to teach concepts, integrate subject matter, build interest, and allow for inquiry--the possibilities are limited only by the imagination of the teacher and the supplies available. In this article, the author shares suggestions and a checklist for setting up successful learning stations. In…

  15. "Inventive" Learning Stations

    Science.gov (United States)

    Jarrett, Olga

    2010-01-01

    Learning stations can be used for myriad purposes--to teach concepts, integrate subject matter, build interest, and allow for inquiry--the possibilities are limited only by the imagination of the teacher and the supplies available. In this article, the author shares suggestions and a checklist for setting up successful learning stations. In…

  16. Meyrin Petrol Station

    CERN Multimedia

    2006-01-01

    Please note that the Meyrin petrol station will be closed for maintenance work on Tuesday 19 and Wednesday 20 December 2006. If you require petrol during this period we invite you to use the Prévessin petrol station, which will remain open. TS-IC-LO Section Tel.: 77039 - 73793

  17. The Roman stational liturgy

    Directory of Open Access Journals (Sweden)

    Janusz Mieczkowski

    2012-03-01

    Full Text Available The papal stational liturgy in Rome was a particular kind of worship service from the Christian Antiquity to the XIV century. Its essential elements are four. Its always took place under the leadership of the pope or his representative. This form of liturgy was mobile: it was celebrated in different basilicas or churches of Rome. Third, the choice of church depended on the feast, liturgical seasons or commemoration being celebrated. Fourth, the stational liturgy was the urban liturgical celebration of the day. The highpoint of this system was Lent. Throughout the entire system Church of Rome manifested its own unity. The station was usually the Pope’s solemn mass in the stational church for the whole city. But on certain days in the year the Pope went in another church (collecta, from which a solemn procession was made to the stational church.

  18. Central Station Design Options

    DEFF Research Database (Denmark)

    2011-01-01

    The purpose of EDISON Work Package 4.1 is the evaluation of possible Central (charging) Stations design options for making possible the public charging of Electric Vehicles (EVs). A number of scenarios for EVs are assessed, with special emphasis on the options of Fast Charging and Battery Swapping....... The work identifies the architecture, sizing and siting of prospective Central Stations in Denmark, which can be located at shopping centers, large car parking lots or gas stations. Central Stations are planned to be integrated in the Danish distribution grid. The Danish island of Bornholm, where a high.......g. due to vandalism, the charge supply circuit is disconnected. More electrical vehicles on the market are capable today of quick charging up to 50 kW power level. The feasibility of Central Stations with fast charging/swapping option, their capacity, design, costs and grid impact, as well as battery...

  19. Concept design of HAYATE : Small satellite for supporting Antarctic geophysical observation

    OpenAIRE

    Yoshihara, Keisuke; Sugiura, Yoshiki; Sekiguchi,Masato; Ui, Kyoichi; Tsurumi,Singo; Nakaya, Koji; Mori, Makoto; Matsunaga, Saburo; Ohkami, Yoshiaki

    1999-01-01

    This paper presents the results of conceptual design of a small communication satellite (HAYATE) for supporting research in Antarctica and remote islands. The HAY ATE satellite collects environmental data from unmanned probes located on the Antarctic ice plate and also transmits data from Syowa Station in Antarctica to Japan and the United States. Through the satellite mission analyses, we confirmed that the HAYATE satellite would be able to gather data for GPS baseline analysis and to observ...

  20. Preliminary Electrical Designs for CTEX and AFIT Satellite Ground Station

    Science.gov (United States)

    2010-03-01

    activated failsafe marker != 0 = 0 Tube 2 Tube 3 Shutdown Describes the primary operation of the experiment control system. [DiS01] Tube Processes: Each...the 400-1,200 nm range. This band is known to contain peaks for Hematites , Geothites and other iron bearing minerals [2]. Looking at this data and...Motion Controllers Motor Amplifier PSU DCCU Power 12-30V DC 56V AC USB General Purpose I/O 32-PIN Proprietary Connection Ethernet Primary Data

  1. Al-Manar and Alhurra: Competing Satellite Stations and Ideologies

    Science.gov (United States)

    2006-10-01

    Other programmes for children include American movies such as Rain Man and Disney cartoons.53 Some programmes are religiously-oriented. One game...are from the point of the view of that enemy, rubbing salt in the wound, as it were. Al-Manar does not conform to stereotypes of it (or of Hizbullah

  2. NUTS: Ground station with GNU Radio and USRP

    OpenAIRE

    Vea, Karl David

    2015-01-01

    Study and describe GNU Radio together with USRP as alternative ground station. Describe and analyze GMSK signal. NGHam link protcol implementation. Simulation on demodulation considering how frequency synchronization can be achieved. Discuss if and how GNU Radio suits the uneversity satellite project.

  3. 47 CFR 22.507 - Number of transmitters per station.

    Science.gov (United States)

    2010-10-01

    ..., stand-alone transmitter is linked to the system via a control/repeater facility or by satellite... 47 Telecommunication 2 2010-10-01 2010-10-01 false Number of transmitters per station. 22.507 Section 22.507 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES...

  4. An enhanced algorithm to estimate BDS satellite's differential code biases

    Science.gov (United States)

    Shi, Chuang; Fan, Lei; Li, Min; Liu, Zhizhao; Gu, Shengfeng; Zhong, Shiming; Song, Weiwei

    2016-02-01

    This paper proposes an enhanced algorithm to estimate the differential code biases (DCB) on three frequencies of the BeiDou Navigation Satellite System (BDS) satellites. By forming ionospheric observables derived from uncombined precise point positioning and geometry-free linear combination of phase-smoothed range, satellite DCBs are determined together with ionospheric delay that is modeled at each individual station. Specifically, the DCB and ionospheric delay are estimated in a weighted least-squares estimator by considering the precision of ionospheric observables, and a misclosure constraint for different types of satellite DCBs is introduced. This algorithm was tested by GNSS data collected in November and December 2013 from 29 stations of Multi-GNSS Experiment (MGEX) and BeiDou Experimental Tracking Stations. Results show that the proposed algorithm is able to precisely estimate BDS satellite DCBs, where the mean value of day-to-day scattering is about 0.19 ns and the RMS of the difference with respect to MGEX DCB products is about 0.24 ns. In order to make comparison, an existing algorithm based on IGG: Institute of Geodesy and Geophysics, China (IGGDCB), is also used to process the same dataset. Results show that, the DCB difference between results from the enhanced algorithm and the DCB products from Center for Orbit Determination in Europe (CODE) and MGEX is reduced in average by 46 % for GPS satellites and 14 % for BDS satellites, when compared with DCB difference between the results of IGGDCB algorithm and the DCB products from CODE and MGEX. In addition, we find the day-to-day scattering of BDS IGSO satellites is obviously lower than that of GEO and MEO satellites, and a significant bias exists in daily DCB values of GEO satellites comparing with MGEX DCB product. This proposed algorithm also provides a new approach to estimate the satellite DCBs of multiple GNSS systems.

  5. 75 FR 44198 - Implementation of Section 203 of the Satellite Television Extension and Localism Act of 2010...

    Science.gov (United States)

    2010-07-28

    ...\\ See Cable Television Report and Order, FCC 72-108, 37 FR 3252, February 3, 1972 (adopting the concept... precondition to satellite carriage of the HD programming of an SV station affiliated with the same network. We... signal of a broadcast station access to broadcast programming via satellite.\\19\\ The 1988 SHVA...

  6. Satellite B-ISDN traffic analysis

    Science.gov (United States)

    Shyy, Dong-Jye; Inukai, Thomas

    1991-01-01

    The impact of asynchronous transfer mode (ATM) traffic on the advanced satellite broadband integrated services digital network (B-ISDN) with onboard processing is reported. Simulation models were built to analyze the cell transfer performance through the statistical multiplexer at the earth station and the fast packet switch at the satellite. The effectiveness of ground ATM cell preprocessing was established, as well as the performance of several schemes for improving the down-link beam utilization when the space segment employs a fast packet switch.

  7. Satellite data compression

    CERN Document Server

    Huang, Bormin

    2011-01-01

    Satellite Data Compression covers recent progress in compression techniques for multispectral, hyperspectral and ultra spectral data. A survey of recent advances in the fields of satellite communications, remote sensing and geographical information systems is included. Satellite Data Compression, contributed by leaders in this field, is the first book available on satellite data compression. It covers onboard compression methodology and hardware developments in several space agencies. Case studies are presented on recent advances in satellite data compression techniques via various prediction-

  8. Waste Transfer Stations

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund

    2011-01-01

    tion and transport is usually the most costly part of any waste management system; and when waste is transported over a considerable distance or for a long time, transferring the waste from the collection vehicles to more efficient transportation may be economically beneficial. This involves...... a transfer station where the transfer takes place. These stations may also be accessible by private people, offering flexibility to the waste system, including facilities for bulky waste, household hazardous waste and recyclables. Waste transfer may also take place on the collection route from small...... describes the main features of waste transfer stations, including some considerations about the economical aspects on when transfer is advisable....

  9. Space station operations management

    Science.gov (United States)

    Cannon, Kathleen V.

    1989-01-01

    Space Station Freedom operations management concepts must be responsive to the unique challenges presented by the permanently manned international laboratory. Space Station Freedom will be assembled over a three year period where the operational environment will change as significant capability plateaus are reached. First Element Launch, Man-Tended Capability, and Permanent Manned Capability, represent milestones in operational capability that is increasing toward mature operations capability. Operations management concepts are being developed to accomodate the varying operational capabilities during assembly, as well as the mature operational environment. This paper describes operations management concepts designed to accomodate the uniqueness of Space Station Freedoom, utilizing tools and processes that seek to control operations costs.

  10. Integration of Quantum Cryptography through Satellite Networks Transmission

    Directory of Open Access Journals (Sweden)

    Skander Aris

    2011-01-01

    Full Text Available Problem statement: The security of the telecommunications satellite has become a crucial issue. The telecommunications can be set using the classical cryptography. But this so-called classical cryptography provides cryptographic security. This means that security is based on the difficulty of some mathematics problems. On the other hand, quantum cryptography provides security without conditions based on the law of quantum physics. This method, called the theoretic information security is evidenced using the theory of information. Approach: In this study, we study whether quantum cryptography can be applied in the frame of the satellite telecommunications network. To do this in our project, we present theories regarding the following issues: Telecommunications Station and Satellite Communication Networks, Quantum Key Distribution, Open Space and Satellites, Analyses in different Scenarios between the Satellite and Earth station. Results: Quantum communications offers many advantages for secure data transmission, in our implementation study, we presented different scenarios of quantum key exchange between satellites and ground stations for possible approach to subsystem with quantum communication in space, capable of generating and detecting entangled photons as well as faint laser pulses. Conclusion: The use of satellites to distribute quantum photon provides a unique solution for long-distance. Moreover, quantum cryptography is a satisfactory solution to improve the safety problem. So, the quantum transmissions are the future of telecommunications.

  11. Seamless Handovers in Cobra Teardrop Satellite Arrays

    Science.gov (United States)

    Draim, John E.; Cefola, Paul J.; Ernandes, Kenneth J.

    2007-06-01

    Satellite systems provide the most efficient and possibly the only means of achieving two-way global communications with mobile systems (ships, aircraft, and vehicular traffic). To date, such systems have used only circular orbits, either GEO or LEO. Medium altitude elliptical constellations, on the other hand, can provide an efficient and affordable alternative to these architectures. Users also benefit from their very high average and minimum elevation angles, resulting in minimum signal attenuation. Cobra Teardrop is unique in that it employs time synchronized 8-h left- and right-leaning elliptical orbits giving mid-latitude observers the illusion of viewing a single satellite continuously orbiting almost directly overhead! In reality, observers see six different satellites per day, for 4 h each (while in their active duty cycles). By design, Teardrop satellites are physically in very close proximity at the handover points. This favorable geometry can be utilized to achieve a seamless handover from one satellite to the other (not requiring any electronic buffering). Handover is accomplished at the precise instant that the total path lengths from the transmitting station through both satellites to the receiving station are exactly equal. In these improved Cobra Teardrop arrays, an order of magnitude increase in global communications capacity (equivalent GEO slots) can be realized over earlier Basic Cobra systems. For decades into the future, these new orbital systems could satisfy a widely expanding range of commercial, government, and military high data rate communication requirements. These would include, but not be limited to, satellite cellular, air traffic control, meteorological, and combat net radio systems. With these arrays, a much larger number of system operators could be supported, without mutual electronic interference, than would ever be possible with circular orbits.

  12. Platelet satellitism in infectious disease?

    Science.gov (United States)

    Laskaj, Renata; Sikiric, Dubravka; Skerk, Visnja

    2015-01-01

    Background Platelet satellitism is a phenomenon of unknown etiology of aggregating platelets around polymorphonuclear neutrophils and other blood cells which causes pseudothrombocytopenia, visible by microscopic examination of blood smears. It has been observed so far in about a hundred cases in the world. Case subject and methods Our case involves a 73-year-old female patient with a urinary infection. Biochemical serum analysis (CRP, glucose, AST, ALT, ALP, GGT, bilirubin, sodium, potassium, chloride, urea, creatinine) and blood cell count were performed with standard methods on autoanalyzers. Serum protein fractions were examined by electrophoresis and urinalysis with standard methods on autoanalyzer together with microscopic examination of urine sediment. Erythrocyte sedimentation rate, blood culture and urine culture tests were performed with standard methods. Results Due to typical pathological values for bacterial urinary infection, the patient was admitted to the hospital. Blood smear examination revealed phenomenon, which has persisted for three weeks after the disease has been cured. Blood smears with EDTA as an anticoagulant had platelet satellitism whereas the phenomenon was not observed in tubes with different anticoagulants (Na, Li-heparin) and capillary blood. Discussion We hypothesize that satellitism was induced by some immunological mechanism through formation of antibodies which have mediated platelets binding to neutrophil membranes and vice versa. Unfortunately we were unable to determine the putative trigger for this phenomenon. To our knowledge this is the second case of platelet satellitism ever described in Croatia. PMID:26110042

  13. 47 CFR 25.220 - Non-conforming transmit/receive earth station operations.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Non-conforming transmit/receive earth station... CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.220 Non-conforming transmit/receive... operator acknowledging that the proposed operation of the subject non-conforming earth station with...

  14. Signal Station Inspection Reports

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Handwritten reports resulting from detailed inspections of US Army Signal Service Stations, 1871-1889. Features reported included instrument exposure and condition,...

  15. FEMA DFIRM Station Start

    Data.gov (United States)

    Minnesota Department of Natural Resources — This table contains information about station starting locations. These locations indicate the reference point that was used as the origin for distance measurements...

  16. "Central Station" Londonis

    Index Scriptorium Estoniae

    2000-01-01

    Londoni galeriis Milch seitsme läti, leedu ja eesti kunstniku projekt "Central Station". Kuraatorid Lisa Panting, Sally Tallant. Eestist osalevad Hanno Soans (Catarina Campinoga koostöös valminud video), Kiwa, Kai Kaljo

  17. Realtime USGS Streamflow Stations

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Approximately 5,000 of the 6,900 U.S. Geological Survey sampling stations are equipped with telemetry to transmit data on streamflow, temperature, and other...

  18. "Central Station" Londonis

    Index Scriptorium Estoniae

    2000-01-01

    Londoni galeriis Milch seitsme läti, leedu ja eesti kunstniku projekt "Central Station". Kuraatorid Lisa Panting, Sally Tallant. Eestist osalevad Hanno Soans (Catarina Campinoga koostöös valminud video), Kiwa, Kai Kaljo

  19. ASOS Station Photos

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The images contained in this library are of stations in the Automated Surface Observing System (ASOS) network. These images were taken between 1998-2001 for the ASOS...

  20. Master Station History Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Standard/Legacy MSHR, formally identified as the DSI-9767 dataset, is the legacy dataset/report sorted by NCDC Station ID and period of record. This...

  1. Materials Test Station

    Data.gov (United States)

    Federal Laboratory Consortium — When completed, the Materials Test Station at the Los Alamos Neutron Science Center will meet mission need. MTS will provide the only fast-reactor-like irradiation...

  2. Natural Weathering Exposure Station

    Data.gov (United States)

    Federal Laboratory Consortium — The Corps of Engineers' Treat Island Natural Weathering Exposure Station is a long-term natural weathering facility used to study concrete durability. Located on the...

  3. Station Management Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The following plan is the result of a recent initiative in Region 5 to produce general management guidance based on stated objectives for individual field stations....

  4. Maine Field Station

    Data.gov (United States)

    Federal Laboratory Consortium — In 2000 NOAA's National Marine Fisheries Service established the Maine Field Station in Orono, ME to have more direct involvement in the conservation of the living...

  5. Electrostatic pickup station

    CERN Multimedia

    CERN PhotoLab

    1982-01-01

    Electrostatic pickup station, with 4 interleaved electrodes, to measure beam position in the horizontal and vertical plane. This type is used in the transfer lines leaving the PS (TT2, TT70, TTL2). See also 7904075.

  6. USRCRN Station Information

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Documentation of United States Regional Climate Reference Network (USRCRN) installations in 2009. Installations documented are for USRCRN pilot project stations in...

  7. Space Station Food System

    Science.gov (United States)

    Thurmond, Beverly A.; Gillan, Douglas J.; Perchonok, Michele G.; Marcus, Beth A.; Bourland, Charles T.

    1986-01-01

    A team of engineers and food scientists from NASA, the aerospace industry, food companies, and academia are defining the Space Station Food System. The team identified the system requirements based on an analysis of past and current space food systems, food systems from isolated environment communities that resemble Space Station, and the projected Space Station parameters. The team is resolving conflicts among requirements through the use of trade-off analyses. The requirements will give rise to a set of specifications which, in turn, will be used to produce concepts. Concept verification will include testing of prototypes, both in 1-g and microgravity. The end-item specification provides an overall guide for assembling a functional food system for Space Station.

  8. Mukilteo Research Station

    Data.gov (United States)

    Federal Laboratory Consortium — Research at the Mukilteo Research Station focuses on understanding the life cycle of marine species and the impacts of ecosystem stressors on anadromous and marine...

  9. TV Analog Station Transmitters

    Data.gov (United States)

    Department of Homeland Security — This file is an extract from the Consolidated Database System (CDBS) licensed by the Media Bureau. It consists of Analog Television Stations (see Rule Part47 CFR...

  10. Public Transit Stations

    Data.gov (United States)

    Department of Homeland Security — fixed rail transit stations within the Continental United States, Alaska, Hawaii, the District of Columbia, and Puerto Rico. The modes of transit that are serviced...

  11. Routes and Stations

    Data.gov (United States)

    Department of Homeland Security — he Routes_Stations table is composed of fixed rail transit systems within the Continental United States, Alaska, Hawaii, the District of Columbia, and Puerto Rico....

  12. Active Marine Station Metadata

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Active Marine Station Metadata is a daily metadata report for active marine bouy and C-MAN (Coastal Marine Automated Network) platforms from the National Data...

  13. Enhanced Master Station History Report

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Enhanced Master Station History Report (EMSHR) is a compiled list of basic, historical information for every station in the station history database, beginning...

  14. LARES succesfully launched in orbit: satellite and mission description

    CERN Document Server

    Paolozzi, Antonio

    2013-01-01

    On February 13th 2012, the LARES satellite of the Italian Space Agency (ASI) was launched into orbit with the qualification flight of the new VEGA launcher of the European Space Agency (ESA). The payload was released very accurately in the nominal orbit. The name LARES means LAser RElativity Satellite and summarises the objective of the mission and some characteristics of the satellite. It is, in fact, a mission designed to test Einstein's General Relativity Theory (specifically 'frame dragging' and Lense-Thirring effect). The satellite is passive and covered with optical retroreflectors that send back laser pulses to the emitting ground station. This allows accurate positioning of the satellite, which is important for measuring the very small deviations from Galilei-Newton's laws. In 2008, ASI selected the prime industrial contractor for the LARES system with a heavy involvement of the universities in all phases of the programme, from the design to the construction and testing of the satellite and separation...

  15. Leadership at Antarctic Stations.

    Science.gov (United States)

    1987-03-01

    Claseification 6. No. Pegees LEADERSHIP AT ANTARTIC STATIONS hxIs i4 5, C =r~eta(C), 17 Rfs~W (R, Udusiied U)J 7. No Refs 8. Author(s) Edocumesnt I...whether there is a "best" approach to leadership at an Antartic Station and what leadership style may have the most to offer. 3~~ __ ___ Tipesis to be

  16. LAERTIS, a multidisciplinary station

    Science.gov (United States)

    Aggouras, G.; Anassontzis, E. G.; Ball, A. E.; Chinowsky, W.; Fahrun, E.; Grammatikakis, G.; Green, C.; Grieder, P.; Katrivanos, P.; Koske, P.; Markopoulos, E.; Minkowsky, P.; Nygren, D.; Papageorgiou, K.; Przybylski, G.; Resvanis, L. K.; Siotis, I.; Sopher, J.; Tsagli, V.; Zhukov, V. A.

    2006-11-01

    LAERTIS, designed to collect environmental data from the deep-sea, is operated since 1999 and has been deployed several time at 4000 m depth at the NESTOR site. Power and data were transferred through a 30-km electro-optical cable to the Shore Station. In this report, we describe briefly the LAERTIS instrumentation and present typical data that were collected successfully during those deployment demonstrating the importance of a deep-sea station permanently connected to shore.

  17. Satellite ATM Networks: Architectures and Guidelines Developed

    Science.gov (United States)

    vonDeak, Thomas C.; Yegendu, Ferit

    1999-01-01

    An important element of satellite-supported asynchronous transfer mode (ATM) networking will involve support for the routing and rerouting of active connections. Work published under the auspices of the Telecommunications Industry Association (http://www.tiaonline.org), describes basic architectures and routing protocol issues for satellite ATM (SATATM) networks. The architectures and issues identified will serve as a basis for further development of technical specifications for these SATATM networks. Three ATM network architectures for bent pipe satellites and three ATM network architectures for satellites with onboard ATM switches were developed. The architectures differ from one another in terms of required level of mobility, supported data rates, supported terrestrial interfaces, and onboard processing and switching requirements. The documentation addresses low-, middle-, and geosynchronous-Earth-orbit satellite configurations. The satellite environment may require real-time routing to support the mobility of end devices and nodes of the ATM network itself. This requires the network to be able to reroute active circuits in real time. In addition to supporting mobility, rerouting can also be used to (1) optimize network routing, (2) respond to changing quality-of-service requirements, and (3) provide a fault tolerance mechanism. Traffic management and control functions are necessary in ATM to ensure that the quality-of-service requirements associated with each connection are not violated and also to provide flow and congestion control functions. Functions related to traffic management were identified and described. Most of these traffic management functions will be supported by on-ground ATM switches, but in a hybrid terrestrial-satellite ATM network, some of the traffic management functions may have to be supported by the onboard satellite ATM switch. Future work is planned to examine the tradeoffs of placing traffic management functions onboard a satellite as

  18. The Princess Elisabeth Station

    Science.gov (United States)

    Berte, Johan

    2012-01-01

    Aware of the increasing impact of human activities on the Earth system, Belgian Science Policy Office (Belspo) launched in 1997 a research programme in support of a sustainable development policy. This umbrella programme included the Belgian Scientific Programme on Antarctic Research. The International Polar Foundation, an organization led by the civil engineer and explorer Alain Hubert, was commissioned by the Belgian Federal government in 2004 to design, construct and operate a new Belgian Antarctic Research Station as an element under this umbrella programme. The station was to be designed as a central location for investigating the characteristic sequence of Antarctic geographical regions (polynia, coast, ice shelf, ice sheet, marginal mountain area and dry valleys, inland plateau) within a radius of 200 kilometers (approx.124 miles) of a selected site. The station was also to be designed as "state of the art" with respect to sustainable development, energy consumption, and waste disposal, with a minimum lifetime of 25 years. The goal of the project was to build a station and enable science. So first we needed some basic requirements, which I have listed here; plus we had to finance the station ourselves. Our most important requirement was that we decided to make it a zero emissions station. This was both a philosophical choice as we thought it more consistent with Antarctic Treaty obligations and it was also a logistical advantage. If you are using renewable energy sources, you do not have to bring in all the fuel.

  19. Applications of two-way satellite time and frequency transfer in the BeiDou navigation satellite system

    Science.gov (United States)

    Zhou, ShanShi; Hu, XiaoGong; Liu, Li; Guo, Rui; Zhu, LingFeng; Chang, ZhiQiao; Tang, ChengPan; Gong, XiuQiang; Li, Ran; Yu, Yang

    2016-10-01

    A two-way satellite time and frequency transfer (TWSTFT) device equipped in the BeiDou navigation satellite system (BDS) can calculate clock error between satellite and ground master clock. TWSTFT is a real-time method with high accuracy because most system errors such as orbital error, station position error, and tropospheric and ionospheric delay error can be eliminated by calculating the two-way pseudorange difference. Another method, the multi-satellite precision orbit determination (MPOD) method, can be applied to estimate satellite clock errors. By comparison with MPOD clock estimations, this paper discusses the applications of the BDS TWSTFT clock observations in satellite clock measurement, satellite clock prediction, navigation system time monitor, and satellite clock performance assessment in orbit. The results show that with TWSTFT clock observations, the accuracy of satellite clock prediction is higher than MPOD. Five continuous weeks of comparisons with three international GNSS Service (IGS) analysis centers (ACs) show that the reference time difference between BeiDou time (BDT) and golbal positoning system (GPS) time (GPST) realized IGS ACs is in the tens of nanoseconds. Applying the TWSTFT clock error observations may obtain more accurate satellite clock performance evaluation in the 104 s interval because the accuracy of the MPOD clock estimation is not sufficiently high. By comparing the BDS and GPS satellite clock performance, we found that the BDS clock stability at the 103 s interval is approximately 10-12, which is similar to the GPS IIR.

  20. 心理咨询技术在基层派出所治安调解中的应用%The Application of Psychological Consultation Technology When Conducting Security Mediations in Police Stations

    Institute of Scientific and Technical Information of China (English)

    杨青

    2016-01-01

    To deeply enhance the effectiveness of public order mediation work and improve police-community relations, this research explored the applications of psychological counseling technology in public order mediation work.The polices on basic level do paper interview by two issues, one is the problems in public order mediation, the other is the feedback and tips of psychological consulting methods'application in public order mediation.The conclusion is that, using listening technology, empathy technology, endoplasmic technology, self-open technology in public order mediation work can significantly improve basic level polices'work efficiency.The application of psychological con-sultation technology has brought new vitality in public order mediation work.%为进一步增强基层派出所治安调解工作的有效性,帮助改善警民关系,研究探索了将心理咨询技术引入治安调解工作中的具体应用方法与注意事项。通过对基层民警在进行治安调解时面临的主要问题和使用心理咨询技术的反馈与心得进行访谈发现,倾听技术、共情技术、面质技术、自我开放技术的应用可以有效提高基层民进治安调解工作的实际效果,为基层治安案件的调解工作注入了新的活力。

  1. Xichang Satellite Launch Center

    Institute of Scientific and Technical Information of China (English)

    LiuJie

    2004-01-01

    Xichang Satellite Launch Center(XSLC) is mainly for geosynchronous orbit launches. The main purpose of XSLC is to launch spacecraft, such as broadcasting,communications and meteorological satellites, into geo-stationary orbit.Most of the commercial satellite launches of Long March vehicles have been from Xichang Satellite Launch Center. With 20 years' development,XSLC can launch 5 kinds of launch vehicles and send satellites into geostationary orbit and polar orbit. In the future, moon exploration satellites will also be launched from XSLC.

  2. Handbook of satellite applications

    CERN Document Server

    Madry, Scott; Camacho-Lara, Sergio

    2017-01-01

    The first edition of this ground breaking reference work was the most comprehensive reference source available about the key aspects of the satellite applications field. This updated second edition covers the technology, the markets, applications and regulations related to satellite telecommunications, broadcasting and networking—including civilian and military systems; precise satellite navigation and timing networks (i.e. GPS and others); remote sensing and meteorological satellite systems. Created under the auspices of the International Space University based in France, this brand new edition is now expanded to cover new innovative small satellite constellations, new commercial launching systems, innovation in military application satellites and their acquisition, updated appendices, a useful glossary and more.

  3. Preliminary Results of the Ground/Orbiter Lasercomm Demonstration Experiment between Table Mountain and teh ETS-V1 Satellite

    Science.gov (United States)

    Wilson, K. E.; Lesh, J. R.; Araki, K.; Arimoto, Y.

    1996-01-01

    The Ground/Orbiter Lasercomm Demonstration (GOLD) is an optical communications demonstration between the Japanese Engineering Test Satellite (ETS-V1) and an optical ground transmitting and receiving station at the Table Mountain FAcility in Wrightwood California. Laser transmissions to the satellite are performed approximately four hours every third night when the satellite is at apogee above Table Mountain.

  4. Preliminary Results of the Ground/Orbiter Lasercomm Demonstration Experiment between Table Mountain and teh ETS-V1 Satellite

    Science.gov (United States)

    Wilson, K. E.; Lesh, J. R.; Araki, K.; Arimoto, Y.

    1996-01-01

    The Ground/Orbiter Lasercomm Demonstration (GOLD) is an optical communications demonstration between the Japanese Engineering Test Satellite (ETS-V1) and an optical ground transmitting and receiving station at the Table Mountain FAcility in Wrightwood California. Laser transmissions to the satellite are performed approximately four hours every third night when the satellite is at apogee above Table Mountain.

  5. Artificial Satellites and How to Observe Them

    CERN Document Server

    Schmude, Jr , Richard

    2012-01-01

    Astronomers' Observing Guides provide up-to-date information for amateur astronomers who want to know all about what it is they are observing. This is the basis for the first part of the book. The second part details observing techniques for practical astronomers, working with a range of different instruments. Every amateur astronomer sees "stars" that aren't natural objects steadily slide across the background of the sky. Artificial satellites can be seen on any night, and some are as bright as the planets. But can you identify which satellite or spent launch vehicle casing you are seeing? Do you know how to image it? Artificial Satellites and How to Observe Them describes all of the different satellites that can be observed, including communication, scientific, spy satellites, and of course, the International Space Station. Richard Schmude describes how to recognize them and even how to predict their orbits. The book tells how to observe artificial satellites with the unaided eye, binoculars and with telesc...

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

    Science.gov (United States)

    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. Observing tectonic plate motions and deformations from satellite laser ranging

    Science.gov (United States)

    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.

  8. STRUVE arc and EUPOS® stations

    Science.gov (United States)

    Lasmane, Ieva; Kaminskis, Janis; Balodis, Janis; Haritonova, Diana

    2013-04-01

    The Struve Geodetic Arc was developed in Years 1816 to 1855, 200 years ago. Historic information on the points of the Struve Geodetic Arc are included in the UNESCO World Heritage list in 2005. Nevertheless, the sites of many points are still not identified nor included in the data bases nowadays. Originally STRUVE arc consisted of 258 main triangles with 265 triangulation points. Currently 34 of the original station points are identified and included in the in the UNESCO World Heritage list. identified original measurement points of the Meridian Arc are located in Sweden (7 points), Norway (15), Finland (83), Russia (1), Estonia (22), Latvia (16), Lithuania (18), Belorussia (28), Ukraine (59) and Moldova (27). In Year 2002 was initiated another large coverage project - European Position Determination System "EUPOS®". Currently there are about 400 continuously operating GNSS (Global Navigation Satellite Systems) stations covering EU countries Estonia, Latvia, Lithuania, Poland, Czech Republic, Slovakia, Hungary, Bulgaria, Romania and East European countries Ukraine and Moldavia. EUPOS® network is a ground based GNSS augmentation system widely used for geodesy, land surveying, geophysics and navigation. It gives the opportunity for fast and accurate position determination never available before. It is an honorable task to use the EUPOS® system for research of the Struve triangulation former sites. Projects with Struve arc can popularize geodesy, geo-information and its meaning in nowadays GIS and GNSS systems. Struve Arc and its points is unique cooperation cross-border object which deserve special attention because of their natural beauty and historical value for mankind. GNSS in geodesy discovers a powerful tool for the verification and validation of the height values of geodetic leveling benchmarks established historically almost 200 years ago. The differential GNSS and RTK methods appear very useful to identify vertical displacement of landscape by means of

  9. Estimation of Satellite PCO Offsets for BeiDou based on MGEX Net Solution

    Science.gov (United States)

    Yize, Zhang; Junping, Chen; Bin, Wu; Jiexian, Wang

    2015-04-01

    BeiDou Satellite Navigation System currently has a total 14 satellites including GEO/IGSO/MEO satellites and providing a regional PNT service. Due to a lack of publicly available antenna phase center offsets (PCO) for the BeiDou satellites, conventional values of (+0.6 m, 0.0 m, +1.1 m) are recommended for orbit and clock determination of the GEO/IGSO/MEO satellites, which needs to be further estimation and refinement. In this paper, we propose a multi-GNSS network solution for the estimation of BeiDou satellite PCO. More than 35 ground stations of International GNSS MGEX tracking network are used to determine the BeiDou satellite PCO. In this strategy, the GPS and BeiDou satellite orbits and clocks are derived from IGS final products, and GPS satellite PCO and PCV are fixed according to igs08.atx. The BeiDou satellites PCO are estimated together with the station clock, troposphere delay and LC combination ambiguity parameter. Result shows that the RMS of phase residuals for all stations is 1.8cm and is 1.6m for code residual, respectively. The estimated PCO is different for each satellite. Appling the new PCO for precise point positioning, we found that the positioning error improves from 6cm to 2cm in height.

  10. Propagation considerations in the American Mobile Satellite system design

    Science.gov (United States)

    Kittiver, Charles; Sigler, Charles E., Jr.

    1993-01-01

    An overview of the American Mobile Satellite Corporation (AMSC) mobile satellite services (MSS) system with special emphasis given to the propagation issues that were considered in the design is presented. The aspects of the voice codec design that effect system performance in a shadowed environment are discussed. The strategies for overcoming Ku-Band rain fades in the uplink and downlink paths of the gateway station are presented. A land mobile propagation study that has both measurement and simulation activities is described.

  11. Determining the Cost Effectiveness of Nano-Satellites

    Science.gov (United States)

    2014-09-01

    Control Network, which has eight Remote Tracking Stations around the globe to communicate with satellites ( Hodges and Woll 2008). The resulting raw...Logan, Utah: AIAA/USU, 2014. Hodges , Len, and Ron Woll. “Air Force Satellite Control Network (AFSCN) Support For Operational Responsive Space (ORS...Warfare Systems Command, 2010. Stacy, Nick . “6U Radar Altimeter Concept.” Paper presented at 6U Cubesat Low Cost Space Missions Workshop. Canberra

  12. Building Flexible Download Plans for Agile Earth-Observing Satellites

    OpenAIRE

    Maillard, A.; Verfaillie, G.; Pralet, C.; J. Jaubert; Desmousceaux, T.

    2014-01-01

    International audience; We consider the problem of downloading observa-tions for a next-generation agile Earth-observing satellite. The goal is to schedule file downloads during ground re-ception station visibility windows while minimizing infor-mation age and promoting the fair sharing of the satellite between users. It is a complex scheduling problem with constraints ranging from unsharable resources to time-dependent processing times. Usually, planning and sche-duling are done on the groun...

  13. UMTS Network Stations

    Science.gov (United States)

    Hernandez, C.

    2010-09-01

    The weakness of small island electrical grids implies a handicap for the electrical generation with renewable energy sources. With the intention of maximizing the installation of photovoltaic generators in the Canary Islands, arises the need to develop a solar forecasting system that allows knowing in advance the amount of PV generated electricity that will be going into the grid, from the installed PV power plants installed in the island. The forecasting tools need to get feedback from real weather data in "real time" from remote weather stations. Nevertheless, the transference of this data to the calculation computer servers is very complicated with the old point to point telecommunication systems that, neither allow the transfer of data from several remote weather stations simultaneously nor high frequency of sampling of weather parameters due to slowness of the connection. This one project has developed a telecommunications infrastructure that allows sensorizadas remote stations, to send data of its sensors, once every minute and simultaneously, to the calculation server running the solar forecasting numerical models. For it, the Canary Islands Institute of Technology has added a sophisticated communications network to its 30 weather stations measuring irradiation at strategic sites, areas with high penetration of photovoltaic generation or that have potential to host in the future photovoltaic power plants connected to the grid. In each one of the stations, irradiance and temperature measurement instruments have been installed, over inclined silicon cell, global radiation on horizontal surface and room temperature. Mobile telephone devices have been installed and programmed in each one of the weather stations, which allow the transfer of their data taking advantage of the UMTS service offered by the local telephone operator. Every minute the computer server running the numerical weather forecasting models receives data inputs from 120 instruments distributed

  14. PRMT7 Preserves Satellite Cell Regenerative Capacity.

    Science.gov (United States)

    Blanc, Roméo Sébastien; Vogel, Gillian; Chen, Taiping; Crist, Colin; Richard, Stéphane

    2016-02-16

    Regeneration of skeletal muscle requires the continued presence of quiescent muscle stem cells (satellite cells), which become activated in response to injury. Here, we report that whole-body protein arginine methyltransferase PRMT7(-/-) adult mice and mice conditionally lacking PRMT7 in satellite cells using Pax7-CreERT2 both display a significant reduction in satellite cell function, leading to defects in regenerative capacity upon muscle injury. We show that PRMT7 is preferentially expressed in activated satellite cells and, interestingly, PRMT7-deficient satellite cells undergo cell-cycle arrest and premature cellular senescence. These defects underlie poor satellite cell stem cell capacity to regenerate muscle and self-renew after injury. PRMT7-deficient satellite cells express elevated levels of the CDK inhibitor p21CIP1 and low levels of its repressor, DNMT3b. Restoration of DNMT3b in PRMT7-deficient cells rescues PRMT7-mediated senescence. Our findings define PRMT7 as a regulator of the DNMT3b/p21 axis required to maintain muscle stem cell regenerative capacity.

  15. PRMT7 Preserves Satellite Cell Regenerative Capacity

    Directory of Open Access Journals (Sweden)

    Roméo Sébastien Blanc

    2016-02-01

    Full Text Available Regeneration of skeletal muscle requires the continued presence of quiescent muscle stem cells (satellite cells, which become activated in response to injury. Here, we report that whole-body protein arginine methyltransferase PRMT7−/− adult mice and mice conditionally lacking PRMT7 in satellite cells using Pax7-CreERT2 both display a significant reduction in satellite cell function, leading to defects in regenerative capacity upon muscle injury. We show that PRMT7 is preferentially expressed in activated satellite cells and, interestingly, PRMT7-deficient satellite cells undergo cell-cycle arrest and premature cellular senescence. These defects underlie poor satellite cell stem cell capacity to regenerate muscle and self-renew after injury. PRMT7-deficient satellite cells express elevated levels of the CDK inhibitor p21CIP1 and low levels of its repressor, DNMT3b. Restoration of DNMT3b in PRMT7-deficient cells rescues PRMT7-mediated senescence. Our findings define PRMT7 as a regulator of the DNMT3b/p21 axis required to maintain muscle stem cell regenerative capacity.

  16. Satellite-Delivered Learning.

    Science.gov (United States)

    Arnall, Gail C.

    1987-01-01

    Discusses the application of satellite information delivery to training. Describes a new trend, horizontal programming. Also discusses vertical programming and in-house production of training materials. Lists vendors of satellite-based training. (CH)

  17. GPS Satellite Simulation Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The GPS satellite simulation facility consists of a GPS satellite simulator controlled by either a Silicon Graphics Origin 2000 or PC depending upon unit under test...

  18. China's Recoverable Satellites

    Institute of Scientific and Technical Information of China (English)

    Tang Boehang

    2008-01-01

    @@ By the end of 2006, China had launched 24 recoverable satellites (FSW) in total. Among them, 23 were launched successfully, of which all but one were successfully recovered. Recoverable satellites launched by China are listed in Table 1.

  19. Satellite Tags- Hawaii EEZ

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Satellite tagging was implemented in 2013. Satellite tagging is conducted using a Dan Inject air rifle and deployment arrows designed by Wildlife Computers. Two...

  20. Technical comparison of several global mobile satellite communications systems

    Science.gov (United States)

    Comparetto, Gary M.

    The era of satellite-based mobile satellite communications (MSC) systems started with the first MARISAT satellite which was launched into a geostationary orbit over the Pacific Ocean in 1976 to provide communications between ships and shore stations. The combination of high cost and unacceptably large equipment has kept the space-based MSC systems from appealing to the wider market of personal mobile communications. The progress made over the last ten years, however, in digital voice processing, satellite technology, and component miniaturization has resulted in the viability of satellite-based mobile satellite communications systems to meet the growing market in personal mobile communications using handsets similar to those currently in use with land-based cellular systems. Three of the more mature LEO/MEO satellite systems are addressed in this paper including GLOBALSTAR, Iridium, and Odyssey. The system architectures of each system are presented along with a description of the satellite and user handset designs and the multiaccess techniques employed. It will be shown that, although a number of similarities exist among the system addressed, each system is unique in a variety of significant design areas. It is concluded that the technical feasibility of satellite-based mobile satellite communications systems seems to be secure. It will be challenging, however, for the vendors to actually develop and deploy these systems in a cost effective, timely, and reliable way that meets a continually evolving set of requirements based upon a rapidly changing technology base.

  1. The Integration of Small Satellites in Maritime Interdiction Operations (MIO)

    Science.gov (United States)

    2012-09-01

    BLANK xiii LIST OF ACRONYMS AND ABBREVIATIONS AIS Automatic Identification system BER Bit Error Rate BGAN Broadband Global Area Network bps...was the Broadband Global Area Network ( BGAN ), a global-coverage network that uses three satellites in geostationary orbits and is provided by...NOCTW WR BGAN Mutualink station Target Ship Interdiction Boat Interdiction Boat GPS Tracking Nuc/Rad Sensor Collaboration Station Nuc/Rad Sensor IP

  2. Satellite communication engineering

    CERN Document Server

    Kolawole, Michael Olorunfunmi

    2013-01-01

    An undeniably rich and thorough guide to satellite communication engineering, Satellite Communication Engineering, Second Edition presents the fundamentals of information communications systems in a simple and succinct way. This book considers both the engineering aspects of satellite systems as well as the practical issues in the broad field of information transmission. Implementing concepts developed on an intuitive, physical basis and utilizing a combination of applications and performance curves, this book starts off with a progressive foundation in satellite technology, and then moves on

  3. Hydrogen Fuelling Stations

    DEFF Research Database (Denmark)

    Rothuizen, Erasmus Damgaard

    This thesis concerns hydrogen fuelling stations from an overall system perspective. The study investigates thermodynamics and energy consumption of hydrogen fuelling stations for fuelling vehicles for personal transportation. For the study a library concerning the components in a hydrogen fuelling...... station has been developed in Dymola. The models include the fuelling protocol (J2601) for hydrogen vehicles made by Society of Automotive Engineers (SAE) and the thermodynamic property library CoolProp is used for retrieving state point. The components in the hydrogen fuelling library are building up....... A system consisting of one high pressure storage tank is used to investigate the thermodynamics of fuelling a hydrogen vehicle. The results show that the decisive parameter for how the fuelling proceeds is the pressure loss in the vehicle. The single tank fuelling system is compared to a cascade fuelling...

  4. Hydrogen vehicle fueling station

    Energy Technology Data Exchange (ETDEWEB)

    Daney, D.E.; Edeskuty, F.J.; Daugherty, M.A. [Los Alamos National Lab., NM (United States)] [and others

    1995-09-01

    Hydrogen fueling stations are an essential element in the practical application of hydrogen as a vehicle fuel, and a number of issues such as safety, efficiency, design, and operating procedures can only be accurately addressed by a practical demonstration. Regardless of whether the vehicle is powered by an internal combustion engine or fuel cell, or whether the vehicle has a liquid or gaseous fuel tank, the fueling station is a critical technology which is the link between the local storage facility and the vehicle. Because most merchant hydrogen delivered in the US today (and in the near future) is in liquid form due to the overall economics of production and delivery, we believe a practical refueling station should be designed to receive liquid. Systems studies confirm this assumption for stations fueling up to about 300 vehicles. Our fueling station, aimed at refueling fleet vehicles, will receive hydrogen as a liquid and dispense it as either liquid, high pressure gas, or low pressure gas. Thus, it can refuel any of the three types of tanks proposed for hydrogen-powered vehicles -- liquid, gaseous, or hydride. The paper discusses the fueling station design. Results of a numerical model of liquid hydrogen vehicle tank filling, with emphasis on no vent filling, are presented to illustrate the usefulness of the model as a design tool. Results of our vehicle performance model illustrate our thesis that it is too early to judge what the preferred method of on-board vehicle fuel storage will be in practice -- thus our decision to accommodate all three methods.

  5. Taiyuan Satellite Launch Center

    Institute of Scientific and Technical Information of China (English)

    LiuJie

    2004-01-01

    There are three major space launch bases in China, the Jiuquan Satellite Launch Center,the Taiyuan Satellite Launch Center and the Xichang Satellite Launch Center. All the three launch centers are located in sparsely populated areas where the terrain is even and the field of vision is broad. Security, transport conditions and the influence of the axial rotation

  6. Geodetic Secor Satellite

    Science.gov (United States)

    1974-06-01

    simple, and had low-power lem. 17 14. Satellite Orientation . The satellite was designed to maintain a constant relationship between the antenna...the same satellite orientation . Further considerations were Th oscillations, however, when higher orbital ranges (500-2500 nautical miles) -, 3 a

  7. TC-2 Satellite Delivered

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    On April 18, 2005, TC-2, the second satellite of Double Star Program (DSP), which was jointly developed by CNSA and ESA, was approved to be delivered to the user after the on-board test and trial operation. The satellite is working well and the performance can meet the user's need. The satellite has collected large amount of valuable scientific data

  8. Phytoplankton Bloom Phenology near Palmer Station Antarctica

    Science.gov (United States)

    Crews, L.; Doney, S. C.; Kavanaugh, M.; Ducklow, H. W.; Schofield, O.; Glover, D. M.

    2015-12-01

    West Antarctic Peninsula (WAP) phytoplankton bloom phenology is coupled to growing season water column stratification precipitated by seasonal warming and the melting of winter sea-ice. Previous studies document declining bloom magnitude over decadal timescales in conjunction with decreasing sea-ice extent and duration in the Northern WAP, but less work has been to done explain the observed inter-annual variability in this region. Here we use a high-resolution in situ time series collected by the Palmer Station Antarctica Long Term Ecological Research program and satellite ocean color imagery to investigate the underlying mechanisms controlling phytoplankton bloom timing and magnitude near Palmer Station. We pair chlorophyll and CTD measurements collected twice per week during the austral summer, 1992—2003, with satellite ocean color and ice fractional cover data to examine bloom development and within-season trends in mixed layer depth. Initial results suggest a possible shift over time with spring/summer blooms occurring earlier in the growing season reflecting earlier sea-ice free conditions. Net phytoplankton accumulation rates are also computed and compared against growth estimates. Our results can be used to develop and validate models of coastal Antarctic primary production that better represent inter-annual primary production variability.

  9. Satellite Contributions to Global Change Studies

    Science.gov (United States)

    Parkinson, Claire L.

    2009-01-01

    By providing a global view with a level playing field (no region missed because of unfavorable surface conditions or political boundaries), satellites have made major contributions to improved monitoring and understanding of our constantly changing planet. The global view has allowed surprising realizations like the relative sparsity of lightning strikes over oceans and the large-scale undulations on the massive Antarctic ice sheet. It has allowed the tracking of all sorts of phenomena, including aerosols, both natural and anthropogenic, as they move with the atmospheric circulation and impact weather and human health. But probably nothing that the global view allows is more important in the long term than its provision. of unbiased data sets to address the issue of global change, considered by many to be among the most important issues facing humankind today. With satellites we can monitor atmospheric temperatures at all latitudes and longitudes, and obtain a global average that lessens the likelihood of becoming endlessly mired in the confusions brought about by the certainty of regional differences. With satellites we can monitor greenhouse gases such as CO2 not just above individual research stations but around the globe. With satellites we can monitor the polar sea ice covers, as we have done since the late 1970s, determining and quantifying the significant reduction in Arctic sea ice and the slight growth in Antarctic sea ice over that period, With satellites we can map the full extent and changes in the Antarctic stratospheric ozone depletions that were first identified from using a single ground station; and through satellite data we have witnessed from afar land surface changes brought about by humans both intentionally, as with wide-scale deforestation, and unintentionally, as with the decay of the Aral Sea. The satellite data are far from sufficient for all that we need in order to understand the global system and forecast its changes, as we also need

  10. A method of time transfer between remote stations via LRO

    Science.gov (United States)

    Hoffman, Evan; Sun, Xiaoli; Skillman, David R.; McGarry, Jan F.; Mao, Dandan

    2014-05-01

    Satellite Laser Ranging (SLR) is a standard geodetic technique that uses the round trip time of light from a ground station to a satellite to determine distance. When combined with a spacecraft detector and timing system, this technique can also be used to transfer time between ground stations, demonstrated by the Time Transfer by Laser Link (T2L2) project by the Centre National d'Etudes Spatiaes (CNES) and Observatorire de la Cote d'Azur (OCA) as well as the Laser Time Transfer (LTT) project by the Shanghai Astronomical Observatory. We describe an additional method of time transfer using simultaneous one-way laser ranging (LR) by two or more ground stations to the Lunar Reconnaissance Orbiter (LRO). A one way ranging is necessary, as two way ranging via retroreflectors for time transfer becomes impractical at lunar distances. The method will utilize the one-way LR currently being performed as a part of the LRO mission, allowing time transfer to be a by-product of the conventional usage of the data. Each ground station is referenced to a Master Clock using a multifrequency all-view GPS receiver at both the ground station and Master Clock locations.The Master Clock is located close enough to the ground station to make ionospheric differences in signal path negligible. Two or more stations range to LRO at the same time and their times of arrival are compared. Results from a ground-based experiment are shown, with sub-nanosecond precision shown to be achievable. Ultimately this measurement will provide a more precise and accurate relation of timing standards between stations, leading to a marked improvement in orbit determination.

  11. Next generation communications satellites: multiple access and network studies

    Science.gov (United States)

    Meadows, H. E.; Schwartz, M.; Stern, T. E.; Ganguly, S.; Kraimeche, B.; Matsuo, K.; Gopal, I.

    1982-01-01

    Efficient resource allocation and network design for satellite systems serving heterogeneous user populations with large numbers of small direct-to-user Earth stations are discussed. Focus is on TDMA systems involving a high degree of frequency reuse by means of satellite-switched multiple beams (SSMB) with varying degrees of onboard processing. Algorithms for the efficient utilization of the satellite resources were developed. The effect of skewed traffic, overlapping beams and batched arrivals in packet-switched SSMB systems, integration of stream and bursty traffic, and optimal circuit scheduling in SSMB systems: performance bounds and computational complexity are discussed.

  12. The Coverage Analysis for Low Earth Orbiting Satellites at Low Elevation

    Directory of Open Access Journals (Sweden)

    Shkelzen Cakaj

    2014-07-01

    Full Text Available Low Earth Orbit (LEO satellites are used for public networking and for scientific purposes. Communication via satellite begins when the satellite is positioned in its orbital position. Ground stations can communicate with LEO satellites only when the satellite is in their visibility region. The duration of the visibility and the communication vary for each LEO satellite pass over the station, since LEO satellites move too fast over the Earth. The satellite coverage area is defined as a region of the Earth where the satellite is seen at a minimum predefined elevation angle. The satellite’s coverage area on the Earth depends on orbital parameters. The communication under low elevation angles can be hindered by natural barriers. For safe communication and for savings within a link budget, the coverage under too low elevation is not always provided. LEO satellites organized in constellations act as a convenient network solution for real time global coverage. Global coverage model is in fact the complementary networking process of individual satellite’s coverage. Satellite coverage strongly depends on elevation angle. To conclude about the coverage variation for low orbiting satellites at low elevation up to 10º, the simulation for attitudes from 600km to 1200km is presented through this paper.

  13. INTERACT Station Catalogue - 2015

    DEFF Research Database (Denmark)

    INTERACT stations are located in all major environmental envelopes of the Arctic providing an ideal platform for studying climate change and its impact on the environment and local communities. Since alpine environments face similar changes and challenges as the Arctic, the INTERACT network also ...

  14. Electrostatic pickup station

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    Electrostatic pickup station, with 4 electrodes, to measure beam position in the horizontal and vertical plane. This type is used in the transfer lines leaving the PS (TT2, TTL2, TT70). See also 8206063, where the electrode shapes are clearly visible.

  15. Kiowa Creek Switching Station

    Energy Technology Data Exchange (ETDEWEB)

    1990-03-01

    The Western Area Power Administration (Western) proposes to construct, operate, and maintain a new Kiowa Creek Switching Station near Orchard in Morgan County, Colorado. Kiowa Creek Switching Station would consist of a fenced area of approximately 300 by 300 feet and contain various electrical equipment typical for a switching station. As part of this new construction, approximately one mile of an existing 115-kilovolt (kV) transmission line will be removed and replaced with a double circuit overhead line. The project will also include a short (one-third mile) realignment of an existing line to permit connection with the new switching station. In accordance with the Council on Environmental Quality (CEQ) regulations for implementing the procedural provisions of the National Environmental Policy Act of 1969 (NEPA), 40 CFR Parts 1500--1508, the Department of Energy (DOE) has determined that an environmental impact statement (EIS) is not required for the proposed project. This determination is based on the information contained in this environmental assessment (EA) prepared by Western. The EA identifies and evaluates the environmental and socioeconomic effects of the proposed action, and concludes that the advance impacts on the human environment resulting from the proposed project would not be significant. 8 refs., 3 figs., 1 tab.

  16. Designing a Weather Station

    Science.gov (United States)

    Roman, Harry T.

    2012-01-01

    The collection and analysis of weather data is crucial to the location of alternate energy systems like solar and wind. This article presents a design challenge that gives students a chance to design a weather station to collect data in advance of a large wind turbine installation. Data analysis is a crucial part of any science or engineering…

  17. Summit Station Skiway Review

    Science.gov (United States)

    2013-03-01

    operating procedures (SOPs) for future construction and maintenance efforts. DISCLAIMER: The contents of this report are not to be used for...Runway Construction .......................................................... 22 Appendix B: Rammsonde Instructions...13. Snow accumulation at Summit Station in the Bamboo Forest. .......................................... 13 Figure 14. Strength of Summit skiway

  18. Galileo Station Keeping Strategy

    Science.gov (United States)

    Perez-Cambriles, Antonio; Bejar-Romero, Juan Antonio; Aguilar-Taboada, Daniel; Perez-Lopez, Fernando; Navarro, Daniel

    2007-01-01

    This paper presents analyses done for the design and implementation of the Maneuver Planning software of the Galileo Flight Dynamics Facility. The station keeping requirements of the constellation have been analyzed in order to identify the key parameters to be taken into account in the design and implementation of the software.

  19. Kiowa Creek Switching Station

    Energy Technology Data Exchange (ETDEWEB)

    1990-03-01

    The Western Area Power Administration (Western) proposes to construct, operate, and maintain a new Kiowa Creek Switching Station near Orchard in Morgan County, Colorado. Kiowa Creek Switching Station would consist of a fenced area of approximately 300 by 300 feet and contain various electrical equipment typical for a switching station. As part of this new construction, approximately one mile of an existing 115-kilovolt (kV) transmission line will be removed and replaced with a double circuit overhead line. The project will also include a short (one-third mile) realignment of an existing line to permit connection with the new switching station. In accordance with the Council on Environmental Quality (CEQ) regulations for implementing the procedural provisions of the National Environmental Policy Act of 1969 (NEPA), 40 CFR Parts 1500--1508, the Department of Energy (DOE) has determined that an environmental impact statement (EIS) is not required for the proposed project. This determination is based on the information contained in this environmental assessment (EA) prepared by Western. The EA identifies and evaluates the environmental and socioeconomic effects of the proposed action, and concludes that the advance impacts on the human environment resulting from the proposed project would not be significant. 8 refs., 3 figs., 1 tab.

  20. Meteorological satellite systems

    CERN Document Server

    Tan, Su-Yin

    2014-01-01

    “Meteorological Satellite Systems” is a primer on weather satellites and their Earth applications. This book reviews historic developments and recent technological advancements in GEO and polar orbiting meteorological satellites. It explores the evolution of these remote sensing technologies and their capabilities to monitor short- and long-term changes in weather patterns in response to climate change. Satellites developed by various countries, such as U.S. meteorological satellites, EUMETSAT, and Russian, Chinese, Japanese and Indian satellite platforms are reviewed. This book also discusses international efforts to coordinate meteorological remote sensing data collection and sharing. This title provides a ready and quick reference for information about meteorological satellites. It serves as a useful tool for a broad audience that includes students, academics, private consultants, engineers, scientists, and teachers.

  1. Theory of geostationary satellites

    CERN Document Server

    Zee, Chong-Hung

    1989-01-01

    Geostationary or equatorial synchronous satellites are a daily reminder of our space efforts during the past two decades. The nightly television satellite weather picture, the intercontinental telecommunications of television transmissions and telephone conversations, and the establishrnent of educational programs in remote regions on Earth are constant reminders of the presence of these satellites. As used here, the term 'geo­ stationary' must be taken loosely because, in the long run, the satellites will not remain 'stationary' with respect to an Earth-fixed reference frame. This results from the fact that these satellites, as is true for all satellites, are incessantly subject to perturbations other than the central-body attraction of the Earth. Among the more predominant pertur­ bations are: the ellipticity of the Earth's equator, the Sun and Moon, and solar radiation pressure. Higher harmonics of the Earth's potential and tidal effects also influence satellite motion, but they are of second­ order whe...

  2. Formulation of geopotential difference determination using optical-atomic clocks onboard satellites and on ground based on Doppler cancellation system

    Science.gov (United States)

    Shen, Ziyu; Shen, Wen-Bin; Zhang, Shuangxi

    2016-08-01

    In this study, we propose an approach for determining the geopotential difference using high-frequency-stability microwave links between satellite and ground station based on Doppler cancellation system. Suppose a satellite and a ground station are equipped with precise optical-atomic clocks (OACs) and oscillators. The ground oscillator emits a signal with frequency fa towards the satellite and the satellite receiver (connected with the satellite oscillator) receives this signal with frequency fb which contains the gravitational frequency shift effect and other signals and noises. After receiving this signal, the satellite oscillator transmits and emits, respectively, two signals with frequencies fb and fc towards the ground station. Via Doppler cancellation technique, the geopotential difference between the satellite and the ground station can be determined based on gravitational frequency shift equation by a combination of these three frequencies. For arbitrary two stations on ground, based on similar procedures as described above, we may determine the geopotential difference between these two stations via a satellite. Our analysis shows that the accuracy can reach 1 m2 s- 2 based on the clocks' inaccuracy of about 10-17 (s s-1) level. Since OACs with instability around 10-18 in several hours and inaccuracy around 10-18 level have been generated in laboratory, the proposed approach may have prospective applications in geoscience, and especially, based on this approach a unified world height system could be realized with one-centimetre level accuracy in the near future.

  3. A global satellite-assisted precipitation climatology

    Science.gov (United States)

    Funk, C.; Verdin, A.; Michaelsen, J.; Peterson, P.; Pedreros, D.; Husak, G.

    2015-10-01

    Accurate representations of mean climate conditions, especially in areas of complex terrain, are an important part of environmental monitoring systems. As high-resolution satellite monitoring information accumulates with the passage of time, it can be increasingly useful in efforts to better characterize the earth's mean climatology. Current state-of-the-science products rely on complex and sometimes unreliable relationships between elevation and station-based precipitation records, which can result in poor performance in food and water insecure regions with sparse observation networks. These vulnerable areas (like Ethiopia, Afghanistan, or Haiti) are often the critical regions for humanitarian drought monitoring. Here, we show that long period of record geo-synchronous and polar-orbiting satellite observations provide a unique new resource for producing high-resolution (0.05°) global precipitation climatologies that perform reasonably well in data-sparse regions. Traditionally, global climatologies have been produced by combining station observations and physiographic predictors like latitude, longitude, elevation, and slope. While such approaches can work well, especially in areas with reasonably dense observation networks, the fundamental relationship between physiographic variables and the target climate variables can often be indirect and spatially complex. Infrared and microwave satellite observations, on the other hand, directly monitor the earth's energy emissions. These emissions often correspond physically with the location and intensity of precipitation. We show that these relationships provide a good basis for building global climatologies. We also introduce a new geospatial modeling approach based on moving window regressions and inverse distance weighting interpolation. This approach combines satellite fields, gridded physiographic indicators, and in situ climate normals. The resulting global 0.05° monthly precipitation climatology, the Climate

  4. A global satellite assisted precipitation climatology

    Directory of Open Access Journals (Sweden)

    C. Funk

    2015-05-01

    Full Text Available Accurate representations of mean climate conditions, especially in areas of complex terrain, are an important part of environmental monitoring systems. As high-resolution satellite monitoring information accumulates with the passage of time, it can be increasingly useful in efforts to better characterize the earth's mean climatology. Current state-of-the-science products rely on complex and sometimes unreliable relationships between elevation and station-based precipitation records, which can result in poor performance in food and water insecure regions with sparse observation networks. These vulnerable areas (like Ethiopia, Afghanistan, or Haiti are often the critical regions for humanitarian drought monitoring. Here, we show that long period of record geo-synchronous and polar-orbiting satellite observations provide a unique new resource for producing high resolution (0.05° global precipitation climatologies that perform reasonably well in data sparse regions. Traditionally, global climatologies have been produced by combining station observations and physiographic predictors like latitude, longitude, elevation, and slope. While such approaches can work well, especially in areas with reasonably dense observation networks, the fundamental relationship between physiographic variables and the target climate variables can often be indirect and spatially complex. Infrared and microwave satellite observations, on the other hand, directly monitor the earth's energy emissions. These emissions often correspond physically with the location and intensity of precipitation. We show that these relationships provide a good basis for building global climatologies. We also introduce a new geospatial modeling approach based on moving window regressions and inverse distance weighting interpolation. This approach combines satellite fields, gridded physiographic indicators, and in situ climate normals. The resulting global 0.05° monthly precipitation climatology

  5. A global satellite assisted precipitation climatology

    Science.gov (United States)

    Funk, Christopher C.; Verdin, Andrew P.; Michaelsen, Joel C.; Pedreros, Diego; Husak, Gregory J.; Peterson, P.

    2015-01-01

    Accurate representations of mean climate conditions, especially in areas of complex terrain, are an important part of environmental monitoring systems. As high-resolution satellite monitoring information accumulates with the passage of time, it can be increasingly useful in efforts to better characterize the earth's mean climatology. Current state-of-the-science products rely on complex and sometimes unreliable relationships between elevation and station-based precipitation records, which can result in poor performance in food and water insecure regions with sparse observation networks. These vulnerable areas (like Ethiopia, Afghanistan, or Haiti) are often the critical regions for humanitarian drought monitoring. Here, we show that long period of record geo-synchronous and polar-orbiting satellite observations provide a unique new resource for producing high resolution (0.05°) global precipitation climatologies that perform reasonably well in data sparse regions. Traditionally, global climatologies have been produced by combining station observations and physiographic predictors like latitude, longitude, elevation, and slope. While such approaches can work well, especially in areas with reasonably dense observation networks, the fundamental relationship between physiographic variables and the target climate variables can often be indirect and spatially complex. Infrared and microwave satellite observations, on the other hand, directly monitor the earth's energy emissions. These emissions often correspond physically with the location and intensity of precipitation. We show that these relationships provide a good basis for building global climatologies. We also introduce a new geospatial modeling approach based on moving window regressions and inverse distance weighting interpolation. This approach combines satellite fields, gridded physiographic indicators, and in situ climate normals. The resulting global 0.05° monthly precipitation climatology, the Climate

  6. The New Very Broadband Seismic Station TROLL, Antarctica

    Science.gov (United States)

    Kvaerna, Tormod; Schweitzer, Johannes; Pirli, Myrto; Roth, Michael

    2013-04-01

    Troll is the name of the Norwegian permanent research station in Dronning Maud Land, Antarctica. The research base is located inside the continent, at an elevation of about 1300 m and at a distance of about 230 km from the shelf ice border. In the first week of February 2012, a new very broadband seismic station was installed at TROLL. Contrary to many other seismic stations inside the Antarctic continent, the new seismic sensor could be installed on bedrock (migmatite), on a hill at about 300 m distance from the main buildings of the Troll research base. A bedrock installation has the advantage that seismic signals are not disturbed by multiples due to the thick Antarctic ice sheet. The equipment consists of a Streckeisen STS-2.5 broadband sensor and a Quanterra Q330HR 26 bit digitizer. All data are transferred in real time via a satellite link to NORSAR for analysis and further distribution. During the first year, the new seismic station and corresponding data transmission has been running very stably. Initial analysis of the station's event detection capability shows that the performance is comparable to, and sometimes better than, the best performing three-component stations of the International Monitoring System (IMS). We will present examples of diurnal and seasonal variations in the background noise level of the station, the observed global, regional and local seismicity, and the very exciting monitoring capabilities of icebergs drifting along the coast of Dronning Maud Land.

  7. Hydrogen Filling Station

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. The Freedom CAR and Freedom FUEL initiatives emphasize the importance of hydrogen as a future transportation fuel. Presently, Las Vegas has one hydrogen fueling station powered by natural gas. However, the use of traditional sources of energy to produce hydrogen does not maximize the benefit. The hydrogen fueling station developed under this grant used electrolysis units and solar energy to produce hydrogen fuel. Water and electricity are furnished to the unit and the output is hydrogen and oxygen. Three vehicles were converted to utilize the hydrogen produced at the station. The vehicles were all equipped with different types of technologies. The vehicles were used in the day-to-day operation of the Las Vegas Valley Water District and monitoring was performed on efficiency, reliability and maintenance requirements. The research and demonstration utilized for the reconfiguration of these vehicles could lead to new technologies in vehicle development that could make hydrogen-fueled vehicles more cost effective, economical, efficient and more widely used. In order to advance the development of a hydrogen future in Southern Nevada, project partners recognized a need to bring various entities involved in hydrogen development and deployment together as a means of sharing knowledge and eliminating duplication of efforts. A road-mapping session was held in Las Vegas in June 2006. The Nevada State Energy Office, representatives from DOE, DOE contractors and LANL, NETL, NREL were present. Leadership from the National hydrogen Association Board of Directors also attended. As a result of this session, a roadmap for hydrogen development was created. This roadmap has the ability to become a tool for use by other road-mapping efforts in the hydrogen community. It could also become a standard template for other states or even countries to approach planning for a hydrogen

  8. Hydrogen Filling Station

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Robert F; Sabacky, Bruce; Anderson II, Everett B; Haberman, David; Al-Hassin, Mowafak; He, Xiaoming; Morriseau, Brian

    2010-02-24

    Hydrogen is an environmentally attractive transportation fuel that has the potential to displace fossil fuels. The Freedom CAR and Freedom FUEL initiatives emphasize the importance of hydrogen as a future transportation fuel. Presently, Las Vegas has one hydrogen fueling station powered by natural gas. However, the use of traditional sources of energy to produce hydrogen does not maximize the benefit. The hydrogen fueling station developed under this grant used electrolysis units and solar energy to produce hydrogen fuel. Water and electricity are furnished to the unit and the output is hydrogen and oxygen. Three vehicles were converted to utilize the hydrogen produced at the station. The vehicles were all equipped with different types of technologies. The vehicles were used in the day-to-day operation of the Las Vegas Valley Water District and monitoring was performed on efficiency, reliability and maintenance requirements. The research and demonstration utilized for the reconfiguration of these vehicles could lead to new technologies in vehicle development that could make hydrogen-fueled vehicles more cost effective, economical, efficient and more widely used. In order to advance the development of a hydrogen future in Southern Nevada, project partners recognized a need to bring various entities involved in hydrogen development and deployment together as a means of sharing knowledge and eliminating duplication of efforts. A road-mapping session was held in Las Vegas in June 2006. The Nevada State Energy Office, representatives from DOE, DOE contractors and LANL, NETL, NREL were present. Leadership from the National hydrogen Association Board of Directors also attended. As a result of this session, a roadmap for hydrogen development was created. This roadmap has the ability to become a tool for use by other road-mapping efforts in the hydrogen community. It could also become a standard template for other states or even countries to approach planning for a hydrogen

  9. An operational satellite remote sensing system for ocean fishery

    Institute of Scientific and Technical Information of China (English)

    MAOZhihua; ZHUQiankun; PANDelu

    2004-01-01

    Ocean environmental information is very important to supporting the fishermen in fishing and satellite remote sensing technology can provide it in large scale and in near real-time. Ocean fishery locations are always far away beyond the coverage of the satellite data received by a land-based satellite receiving station. A nice idea is to install the satellite ground station on a fishing boat. When the boat moves to a fishery location, the station can receive the satellite data to cover the fishery areas. One satellite remote sensing system was once installed in a fishing boat and served fishing in the North Pacific fishery areas when the boat stayed there. The system can provide some oceanic environmental charts such as sea surface temperature (SST) and relevant derived products which are in most popular use in fishery industry. The accuracy of SST is the most important and affects the performance of the operational system, which is found to be dissatisfactory. Many factors affect the accuracy of SST and it is difficult to increase the accuracy by SST retrieval algorithms and clouds detection technology. A new technology of temperature error control is developed to detect the abnormity of satellite-measured SST. The performance of the technology is evaluated to change the temperature bias from-3.04 to 0.05 ℃ and the root mean square (RMS) from 5.71 to 1.75 ℃. It is suitable for employing in an operational satellite-measured SST system and improves the performance of the system in fishery applications. The system has been running for 3 a and proved to be very useful in fishing. It can help to locate the candidates of the fishery areas and monitor the typhoon which is very dangerous to the safety of fishing boats.

  10. Battery charging stations

    Energy Technology Data Exchange (ETDEWEB)

    Bergey, M.

    1997-12-01

    This paper discusses the concept of battery charging stations (BCSs), designed to service rural owners of battery power sources. Many such power sources now are transported to urban areas for recharging. A BCS provides the opportunity to locate these facilities closer to the user, is often powered by renewable sources, or hybrid systems, takes advantage of economies of scale, and has the potential to provide lower cost of service, better service, and better cost recovery than other rural electrification programs. Typical systems discussed can service 200 to 1200 people, and consist of stations powered by photovoltaics, wind/PV, wind/diesel, or diesel only. Examples of installed systems are presented, followed by cost figures, economic analysis, and typical system design and performance numbers.

  11. 47 CFR 76.127 - Satellite sports blackout.

    Science.gov (United States)

    2010-10-01

    ... rights to a sports event, or its agent, no satellite carrier shall retransmit to subscribers within the...” carrying the live television broadcast of a sports event if the event is not available live on a television... television station licensed to the community in which the sports event is taking place, the...

  12. Two-way time transfers between NRC/NBS and NRC/USNO via the Hermes (CTS) satellite

    Science.gov (United States)

    Costain, C. C.; Daams, H.; Boulanger, J. S.; Hanson, D. W.; Klepczynski, W. J.

    1978-01-01

    At each station the differences were measured between the local UTC seconds pulse and the remote UTC pulse received by satellite. The difference between the readings, if station delays are assumed to be symmetrical, is two times the difference between the clocks at the two ground station sites. Over a 20-minute period, the precision over the satellite is better than 1 ns. The time transfer from NRC to the CRC satellite terminal near Ottawa and from NBS to the Denver HEW terminal was examined.

  13. Weigh-in-Motion Stations

    Data.gov (United States)

    Department of Homeland Security — The data included in the GIS Traffic Stations Version database have been assimilated from station description files provided by FHWA for Weigh-in-Motion (WIM), and...

  14. Mesocarnivore Photo Stations [ds26

    Data.gov (United States)

    California Department of Resources — This database was established to record furbearer and raptor presence through photographs taken at camera stations. The general study area where camera stations were...

  15. Emergency Medical Service (EMS) Stations

    Data.gov (United States)

    Kansas Data Access and Support Center — EMS Locations in Kansas The EMS stations dataset consists of any location where emergency medical services (EMS) personnel are stationed or based out of, or where...

  16. Automatic Traffic Recorder (ATR) Stations

    Data.gov (United States)

    Department of Homeland Security — The data included in the GIS Traffic Stations Version database have been assimilated from station description files provided by FHWA for Weigh-in-Motion (WIM), and...

  17. Genetic Algorithms for Satellite Scheduling Problems

    Directory of Open Access Journals (Sweden)

    Fatos Xhafa

    2012-01-01

    Full Text Available Recently there has been a growing interest in mission operations scheduling problem. The problem, in a variety of formulations, arises in management of satellite/space missions requiring efficient allocation of user requests to make possible the communication between operations teams and spacecraft systems. Not only large space agencies, such as ESA (European Space Agency and NASA, but also smaller research institutions and universities can establish nowadays their satellite mission, and thus need intelligent systems to automate the allocation of ground station services to space missions. In this paper, we present some relevant formulations of the satellite scheduling viewed as a family of problems and identify various forms of optimization objectives. The main complexities, due highly constrained nature, windows accessibility and visibility, multi-objectives and conflicting objectives are examined. Then, we discuss the resolution of the problem through different heuristic methods. In particular, we focus on the version of ground station scheduling, for which we present computational results obtained with Genetic Algorithms using the STK simulation toolkit.

  18. Space Station fluid management logistics

    Science.gov (United States)

    Dominick, Sam M.

    1990-01-01

    Viewgraphs and discussion on space station fluid management logistics are presented. Topics covered include: fluid management logistics - issues for Space Station Freedom evolution; current fluid logistics approach; evolution of Space Station Freedom fluid resupply; launch vehicle evolution; ELV logistics system approach; logistics carrier configuration; expendable fluid/propellant carrier description; fluid carrier design concept; logistics carrier orbital operations; carrier operations at space station; summary/status of orbital fluid transfer techniques; Soviet progress tanker system; and Soviet propellant resupply system observations.

  19. Station Climatic Summaries, Latin America.

    Science.gov (United States)

    1987-11-01

    265 MEXICO - Acapulco 768056 8403 ................................ 267 Campeche 766950 8403................271 Chetumal 767500...0 0 1 # # I I # or I OPERATIONAL CLIMATIC DATA SUMMARY STATION: CHETUMAL , MEXICO STATIONS #: 767500 1CAO ID: NILC LOCATION: 18030’N, 88*18’W...0 0 0 0 0 0 # ALL HOURS I # # 1 # # # # # # 1 1 ]% OPERATIONAL CLIMATIC DATA SUMMARY SUPPLEMENT STATION: CHETUMAL , MEXICO STATIONS #: 767500 ICAO ID

  20. Mobile satellite communications handbook

    CERN Document Server

    Cochetti, Roger

    2014-01-01

    With a Preface by noted satellite scientist Dr. Ahmad Ghais, the Second Edition reflects the expanded user base for this technology by updating information on historic, current, and planned commercial and military satellite systems and by expanding sections that explain the technology for non-technical professionals.   The book begins with an introduction to satellite communications and goes on to provide an overview of the technologies involved in mobile satellite communications, providing basic introductions to RF Issues, power Issues, link issues and system issues. It describes

  1. Satellite communication antenna technology

    Science.gov (United States)

    Mittra, R. (Editor); Imbriale, W. A. (Editor); Maanders, E. J. (Editor)

    1983-01-01

    A general overview of current technology in the field of communication satellite antennas is presented. Among the topics discussed are: the design of multiple beam systems; frequency reuse; and polarization control of antenna measurements. Consideration is also given to: contour beam synthesis; dual shaped reflector synthesis; beam shaping; and offset reflector design. The applications of the above technologies to present and future generations of communications satellites is considered, with emphasis given to such systems as: the Intelsats; the Defense Satellite Communications System, (DSCS-III); Satellite Business System (SBS), and Comstar.

  2. Methods of satellite oceanography

    Science.gov (United States)

    Stewart, R. H.

    1985-01-01

    The theoretical basis for remote sensing measurements of climate and ocean dynamics is examined. Consideration is given to: the absorption of electromagnetic radiation in the atmosphere; scattering in the atmosphere; and satellite observations using visible light. Consideration is also given to: the theory of radio scatter from the sea; scatter of centimeter waves from the sea; and the theory of operation of synthetic aperture radars. Additional topics include: the coordinate systems of satellite orbits for oceanographic remote sensing applications; the operating features of the major U.S. satellite systems for viewing the ocean; and satellite altimetry.

  3. Build Your Own Space Station

    Science.gov (United States)

    Bolinger, Allison

    2016-01-01

    This presentation will be used to educate elementary students on the purposes and components of the International Space Station and then allow them to build their own space stations with household objects and then present details on their space stations to the rest of the group.

  4. Air and radiation monitoring stations

    CERN Multimedia

    AUTHOR|(SzGeCERN)582709

    2015-01-01

    CERN has around 100 monitoring stations on and around its sites. New radiation measuring stations, capable of detecting even lower levels of radiation, were installed in 2014. Two members of HE-SEE group (Safety Engineering and Environment group) in front of one of the new monitoring stations.

  5. Thermal management of space stations

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Thermal management aims at making full use of energy resources available in the space station to reduce energy consumption, waste heat rejection and the weight of the station. It is an extension of the thermal control. This discussion introduces the concept and development of thermal management, presents the aspects of thermal management and further extends its application to subsystems of the space station.

  6. 47 CFR 80.519 - Station identification.

    Science.gov (United States)

    2010-10-01

    ... MARITIME SERVICES Private Coast Stations and Marine Utility Stations § 80.519 Station identification. (a) Stations must identify transmissions by announcing in the English language the station's assigned call sign...) Marine utility stations, private coast stations, and associated hand-held radios, when...

  7. Two way satellite communication for telemetrology and remote control

    Science.gov (United States)

    Hanebrekke, H.

    Low-data-rate satellite communication to fixed and floating buoys at sea, remote observation stations, and fishing vessels is studied. Particular attention is paid to Norwegian conditions, that is, high latitude and high mountains. Coverage and reliability measurements utilizing Inmarsat C and Prodat stations have been done along the coast of western and northern Norway, and on major roads in southern Norway. Good coverage is found in the coastal areas, with only 5 percent loss of messages when both the AOR and IOR satellites are used from the same location, whereas the land mobile experiments gave 40 percent to 70 percent loss, depending on the elevation angle. The possibility of using Inmarsat C or Prodat stations in the major fishing areas between Norway, Greenland, and Svalbard and in the Barents Sea are also being investigated. A method of data collection from ocean areas based on the fishing fleet is proposed.

  8. TOLNET – A Tropospheric Ozone Lidar Profiling Network for Satellite Continuity and Process Studies

    Directory of Open Access Journals (Sweden)

    Newchurch Michael J.

    2016-01-01

    Full Text Available Ozone lidars measure continuous, high-resolution ozone profiles critical for process studies and for satellite validation in the lower troposphere. However, the effectiveness of lidar validation by using single-station data is limited. Recently, NASA initiated an interagency ozone lidar observation network under the name TOLNet to promote cooperative multiple-station ozone-lidar observations to provide highly timeresolved (few minutes tropospheric-ozone vertical profiles useful for air-quality studies, model evaluation, and satellite validation. This article briefly describes the concept, stations, major specifications of the TOLNet instruments, and data archiving.

  9. Economics of satellite communications systems

    Science.gov (United States)

    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

  10. Laser experiments in light cloudiness with the geostationary satellite ARTEMIS

    Science.gov (United States)

    Kuzkov, V.; Kuzkov, S.; Sodnik, Z.

    2016-08-01

    The geostationary satellite ARTEMIS was launched in July 2001. The satellite is equipped with a laser communication terminal, which was used for the world's first inter-satellite laser communication link between ARTEMIS and the low earth orbit satellite SPOT-4. Ground-to-space laser communication experiments were also conducted under various atmospheric conditions involving ESA's optical ground station. With a rapidly increasing volume of information transferred by geostationary satellites, there is a rising demand for high-speed data links between ground stations and satellites. For ground-to-space laser communications there are a number of important design parameters that need to be addressed, among them, the influence of atmospheric turbulence in different atmospheric conditions and link geometries. The Main Astronomical Observatory of NAS of Ukraine developed a precise computer tracking system for its 0.7 m AZT-2 telescope and a compact laser communication package LACES (Laser Atmosphere and Communication experiments with Satellites) for laser communication experiments with geostationary satellites. The specially developed software allows computerized tracking of the satellites using their orbital data. A number of laser experiments between MAO and ARTEMIS were conducted in partial cloudiness with some amount of laser light observed through clouds. Such conditions caused high break-up (splitting) of images from the laser beacon of ARTEMIS. One possible explanation is Raman scattering of photons on molecules of a water vapor in the atmosphere. Raman scattering causes a shift in a wavelength of the photons.In addition, a different value for the refraction index appears in the direction of the meridian for the wavelength-shifted photons. This is similar to the anomalous atmospheric refraction that appears at low angular altitudes above the horizon. We have also estimated the atmospheric attenuation and the influence of atmospheric turbulence on observed results

  11. Optimizing Satellite Communications With Adaptive and Phased Array Antennas

    Science.gov (United States)

    Ingram, Mary Ann; Romanofsky, Robert; Lee, Richard Q.; Miranda, Felix; Popovic, Zoya; Langley, John; Barott, William C.; Ahmed, M. Usman; Mandl, Dan

    2004-01-01

    A new adaptive antenna array architecture for low-earth-orbiting satellite ground stations is being investigated. These ground stations are intended to have no moving parts and could potentially be operated in populated areas, where terrestrial interference is likely. The architecture includes multiple, moderately directive phased arrays. The phased arrays, each steered in the approximate direction of the satellite, are adaptively combined to enhance the Signal-to-Noise and Interference-Ratio (SNIR) of the desired satellite. The size of each phased array is to be traded-off with the number of phased arrays, to optimize cost, while meeting a bit-error-rate threshold. Also, two phased array architectures are being prototyped: a spacefed lens array and a reflect-array. If two co-channel satellites are in the field of view of the phased arrays, then multi-user detection techniques may enable simultaneous demodulation of the satellite signals, also known as Space Division Multiple Access (SDMA). We report on Phase I of the project, in which fixed directional elements are adaptively combined in a prototype to demodulate the S-band downlink of the EO-1 satellite, which is part of the New Millennium Program at NASA.

  12. Determination of the tectonic plate motion by satellite laser ranging in 1999-2003

    Science.gov (United States)

    Schillak, S.; Wnuk, E.

    The paper presents results of the tectonic plates motion determination from satellite laser ranging in the period 1999-2003 The SLR station velocities were calculated from station geocentric coordinates determined from one month orbital arcs of Lageos-1 and Lageos-2 satellites for the first day of each arc The mean orbital RMS-of-fit for 5 years was equal to 15 mm The station velocities were determined for 29 stations and points in 1999-2003 it means for all SLR stations with data time span longer than 20 months The accuracy of station velocities determination varied from 0 4 mm year to 3 mm year dependent on quality of data and data span The difference of station velocities between ITRF2000 and the presented results were in the range 0-5 mm year Only for four stations Riyad Maidanak-2 Beijng and Arequipa after earthquake in 2001 the differences were statistically significant For the most stations is a good agreement with the NUVEL1A model of tectonic plates motion The significant differences were detected for stations Arequipa Concepcion Shanghai and Simosato The results differs from the model NUVEL1A in the station velocities and azimuths for South America tectonic plate and Japan

  13. Design description report for a photovoltaic power system for a remote satellite earth terminal

    Science.gov (United States)

    Marshall, N. A.; Naff, G. J.

    1987-01-01

    A photovoltaic (PV) power system has been installed as an adjunct to an agricultural school at Wawatobi on the large northern island of the Republic of Indonesia. Its purpose is to provide power for a satellite earth station and a classroom. The renewable energy developed supports the video and audio teleconferencing systems as well as the facility at large. The ground station may later be used to provide telephone service. The installation was made in support of the Agency for International Development's Rural Satellite Program, whose purpose is to demonstrate the use of satellite communications for rural development assistance applications. The objective of this particular PV power system is to demonstrate the suitability of a hybrid PV engine-generator configuration for remote satellite earth stations.

  14. Advanced spacecraft tracking techniques using the Tracking and Data Relay Satellite System /TDRSS/

    Science.gov (United States)

    Teles, J.; Ayres, C.

    1977-01-01

    The TDRSS will consist initially of two geosynchronous satellites and a common ground station at White Sands, New Mexico. According to current schedules, operations are to begin in November 1980. The overall TDRSS will provide high and low bit-rate telemetry, commands, and satellite-to-satellite tracking services. Each Tracking and Data Relay Satellite (TDRS) will have four antenna systems for NASA use. The common ground station at White Sands will have three 18-meter K-band antennas. The tracking equipment at the ground station is required to meet the following specifications: (1) 0.1-radian root-mean-square (rms) phase noise on nondestruct Doppler measurements; (2) 10-nanosecond rms range noise; (3) 50-nanosecond maximum systematic range error. Attention is given to two-way range and Doppler measurements, the bilateration tracking of TDRS, and an experiment using differenced one-way Doppler measurements.

  15. Satellites of spiral galaxies

    Science.gov (United States)

    Zaritsky, Dennis; Smith, Rodney; Frenk, Carlos; White, Simon D. M.

    1993-01-01

    We present a survey of satellites around a homogeneous set of late-type spirals with luminosity similar to that of the Milky Way. On average, we find fewer than 1.5 satellites per primary, but we argue that we can treat the survey as an ensemble and so derive the properties of the halo of a 'typical' isolated spiral. The projected density profile of the ensemble falls off approximately as 1/r. Within 50 kpc the azimuthal distribution of satellites shows some evidence for the 'Holmberg effect', an excess near the minor axis of the primary; however, at larger projected distances, the distribution appears isotropic. There is a weak but significant correlation between the size of a satellite and its distance from its primary, as expected if satellites are tidally truncated. Neither Hubble type nor spectral characteristics correlate with apparent separation. The ensemble of satellites appears to be rotating at about 30 km/s in the same direction as the galactic disk. Satellites on prograde orbits tend to be brighter than those on retrograde orbits. The typical velocity difference between a satellite and its primary shows no clear dependence either on apparent separation, or on the rotation speed of the primary. Thus our survey demonstrates that isolated spiral galaxies have massive halos that extend to many optical radii.

  16. Communication satellite technology trends

    Science.gov (United States)

    Cuccia, Louis

    1986-01-01

    A chronology of space-Earth interconnectivity is presented. The Advanced Communications Technology Satellite (ACTS) system, Land Mobile Satellite, space-Earth antennas, impact of antenna size on coverage, intersatellite links are outlined. This presentation is represented by graphs and charts only.

  17. Soviet satellite communications science and technology

    Energy Technology Data Exchange (ETDEWEB)

    Birch, J.N.; Campanella, S.J.; Gordon, G.D.; McElroy, D.R.; Pritchard, W.L.; Stamminger, R.

    1991-08-01

    This is a report by six US scientists and engineers concerning the current state of the art and projections of future Soviet satellite communications technologies. The panel members are experts in satellite stabilization, spacecraft environments, space power generation, launch systems, spacecraft communications sciences and technologies, onboard processing, ground stations, and other technologies that impact communications. The panel assessed the Soviet ability to support high-data-rate space missions at 128 Mbps by evaluating current and projected Soviet satellite communications technologies. A variety of space missions were considered, including Earth-to-Earth communications via satellites in geostationary or highly elliptical orbits, those missions that require space-to-Earth communications via a direct path and those missions that require space-to-Earth communications via a relay satellite. Soviet satellite communications capability, in most cases, is 10 years behind that of the United States and other industrialized nations. However, based upon an analysis of communications links needed to support these missions using current Soviet capabilities, it is well within the current Soviet technology to support certain space missions outlined above at rates of 128 Mbps or higher, although published literature clearly shows that the Soviet Union has not exceeded 60 Mbps in its current space system. These analyses are necessary but not sufficient to determine mission data rates, and other technologies such as onboard processing and storage could limit the mission data rate well below that which could actually be supported via the communications links. Presently, the Soviet Union appears to be content with data rates in the low-Earth-orbit relay via geostationary mode of 12 Mbps. This limit is a direct result of power amplifier limits, spacecraft antenna size, and the utilization of K{sub u}-band frequencies. 91 refs., 16 figs., 15 tabs.

  18. Estimating Tropical Cyclone Precipitation from Station Observations

    Institute of Scientific and Technical Information of China (English)

    REN Fumin; WANG Yongmei; WANG Xiaoling; LI Weijing

    2007-01-01

    In this paper, an objective technique for estimating the tropical cyclone (TC) precipitation from station observations is proposed. Based on a comparison between the Original Objective Method (OOM) and the Expert Subjective Method (ESM), the Objective Synoptic Analysis Technique (OSAT) for partitioning TC precipitation was developed by analyzing the western North Pacific (WNP) TC historical track and the daily precipitation datasets. Being an objective way of the ESM, OSAT overcomes the main problems in OOM,by changing two fixed parameters in OOM, the thresholds for the distance of the absolute TC precipitation (D0) and the TC size (D1), into variable parameters.Case verification for OSAT was also carried out by applying CMORPH (Climate Prediction Center MORPHing technique) daily precipitation measurements, which is NOAA's combined satellite precipitation measurement system. This indicates that OSAT is capable of distinguishing simultaneous TC precipitation rain-belts from those associated with different TCs or with middle-latitude weather systems.

  19. Results of the Ongoing Monitoring of the Position of a Geostationary Telecommunication Satellite by the Method of Spatially Separated Basis Receiving of Digital Satellite Television Signals

    Science.gov (United States)

    Bushuev, F.; Kaliuzhnyi, M.; Sybiryakova, Y.; Shulga, O.; Moskalenko, S.; Balagura, O.; Kulishenko, V.

    2016-10-01

    The results of the ongoing monitoring of the position of geostationary telecommunication satellite Eutelsat-13B (13° East) are presented in the article. The results were obtained using a radio engineering complex (RC) of four stations receiving digital satellite television and a data processing centre. The stations are located in Kyiv, Mukachevo, Kharkiv and Mykolaiv. The equipment of each station allows synchronous recording (by the GPS) of fragments of DVB-S signal from the quadrature detector output of the satellite television receiver. Samples of the complex signal are archived and sent to the data processing center through the Internet. Here three linearly independent slant range differences (Δr) for three pairs of the stations are determined as a result of correlation processing of received signals. Every second measured values of Δr are used to calculate Cartesian coordinates (XYZ) of the satellite in the coordinate system WGS84 by multilateration method. The time series of Δr, X, Y and Z obtained during continuous observations from March to May 2015 are presented in the article. Single-measurement errors of Δr, X, Y and Z are equal to 2.6 m, 3540 m, 705 m and 455 m, respectively. The complex is compared with known analogues. Ways of reduction of measurement errors of satellite coordinates are considered. The radio engineering complex could be considered a prototype of a system of independent ongoing monitoring of the position of geostationary telecommunication satellites.

  20. Large Deployable Reflector (LDR) Requirements for Space Station Accommodations

    Science.gov (United States)

    Crowe, D. A.; Clayton, M. J.; Runge, F. C.

    1985-01-01

    Top level requirements for assembly and integration of the Large Deployable Reflector (LDR) Observatory at the Space Station are examined. Concepts are currently under study for LDR which will provide a sequel to the Infrared Astronomy Satellite and the Space Infrared Telescope Facility. LDR will provide a spectacular capability over a very broad spectral range. The Space Station will provide an essential facility for the initial assembly and check out of LDR, as well as a necessary base for refurbishment, repair and modification. By providing a manned platform, the Space Station will remove the time constraint on assembly associated with use of the Shuttle alone. Personnel safety during necessary EVA is enhanced by the presence of the manned facility.

  1. Land mobile satellite services in Europe

    Science.gov (United States)

    Bartholome, P.; Rogard, R.; Berretta, G.

    1988-10-01

    The potential role of satellite communication as a complement to the pan-European cellular telephone network being developed to replace the current national or regional networks in the mid 1990s is discussed. The design concept and capabilities of the all-digital cellular network are reviewed; the requirements not covered by the network are listed; market-survey results indicating business interest in these additional services are summarized; and particular attention is given to the ESA demonstration system PRODAT. PRODAT uses the Marecs satellite to provide low-rate two-way data transmission for mobile terminals; the CDMA technique is used for the return links from mobile unit to hub station.

  2. Compressor station layout considerations

    Energy Technology Data Exchange (ETDEWEB)

    Kurz, Rainer; Ohanian, Sebouh; Lubomirsky, Matt [Solar Turbines Incorporated, San Diego, CA (United States)

    2003-07-01

    This paper discusses issues that influence the decision on the arrangement of compressors and the type of equipment in gas pipeline compressor stations. Different concepts such as multiple small units versus single large units are considered, both regarding their impact on the individual station and the overall pipeline. The necessity of standby units is discussed. Various concepts for drivers (gas turbine, gas motor and electric motor) and compressors (centrifugal and reciprocating) are analyzed. The importance of considering all possible operating conditions is stressed. With the wide range of possible operating conditions for the pipeline in mind, the discussion is brought into the general context of operational flexibility, availability, reliability, installation issues, remote control, and operability of gas turbine driven centrifugal compressors compared to other solutions such as electric motor driven compressors or gas engine driven reciprocating compressors. The impact of different concepts on emissions and fuel cost is discussed. Among the assumptions in this paper are the performance characteristics of the compressor. This paper outlines how these performance characteristics influence the conclusions. (author)

  3. Satellite laser ranging measurements in South Africa: Contributions to earth system sciences

    Directory of Open Access Journals (Sweden)

    Christina M. Botai

    2015-03-01

    Full Text Available This contribution reassesses progress in the development of satellite laser ranging (SLR technology and its scientific and societal applications in South Africa. We first highlight the current global SLR tracking stations within the framework of the International Laser Ranging Service (ILRS and the artificial satellites currently being tracked by these stations. In particular, the present work focuses on analysing SLR measurements at Hartebeesthoek Radio Astronomy Observatory (HartRAO, South Africa, based on the MOBLAS-6 SLR configuration. Generally, there is a weak geometry of ILRS stations in the southern hemisphere and the SLR tracking station at HartRAO is the only active ILRS station operating on the African continent. The SLR-derived products such as station positions and velocities, satellite orbits, components of earth's gravity field and their temporal variations, earth orientation parameters are collected, merged, achieved and distributed by the ILRS under the Crustal Dynamic Data Information System. These products are used in various research fields such as detection and monitoring of tectonic plate motion, crustal deformation, earth rotation, polar motion, and the establishment and monitoring of International Terrestrial Reference Frames, as well as modelling of the spatio-temporal variations of the earth's gravity field. The MOBLAS-6 tracking station is collocated with other geodetic techniques such as very long baseline interferometry and Global Navigation Satellite Systems, thus making this observatory a fiducial geodetic location. Some applications of the SLR data products are described within the context of earth system science.

  4. Global maritime mobile service via satellite - The INMARSAT system now and in the future

    Science.gov (United States)

    Snowball, A. E.

    1986-06-01

    The business and technical aspects of the INMARSAT (International Maritime Satellite Organization) system are reviewed along with its present capabilities and services and future developments now being considered. The initial phase of maritime mobile satellite communications began with the introduction by the U.S. of the Marisat system in 1976, satisfying a commitment made by COMSAT (Communications Satellite Corp.) in 1973 to provide a maritime satellite service. The Marisat Consortium, spun off by COMSAT, launched three satellites in 1973 - one to serve shipping in the Atlantic, one for the Pacific, and the third as a spare; the spare was subsequently positioned over the Indian Ocean so that the three provided almost global coverage. Each satellite was served by a coast earth station with a 13-m antenna; satellite-earth station links operated in the 6 and 4-GHz bands and the ship-satellite links were at 1.5 and 1.6 GHz. Superceding the limited Marisat system, the INMARSAT Organization, established in July 1979 and first in service on Feb. 1, 1982, now provides communications through a system of Marecs, Intelsat-V, and Marisat satellites. With 41 Signatories by mid-1985, the organization consists of an Assembly, a Council, and a Directorate. Services provided include: telephone; facsimile; low-speed data; high-speed data; telex; telegram; distress, urgency and safety communications; shore-to-ship group calls; various information and assistance services. Coast earth stations, ship earth stations, network coordination stations, and the London headquarters and operations control center are described. Future developments will include an expanded capacity network, digital services, and a role in the Future Global Maritime Distress and Safety System that will use radio beacons that will automatically transmit distress messages to land-based emergency centers in the event of a disaster at sea.

  5. 622 Mbps High-speed satellite communication system for WINDS

    Science.gov (United States)

    Ogawa, Yasuo; Hashimoto, Yukio; Yoshimura, Naoko; Suzuki, Ryutaro; Gedney, Richard T.; Dollard, Mike

    2006-07-01

    WINDS is the experimental communications satellite currently under joint development by Japanese Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT). The high-speed satellite communication system is very effective for quick deployment of high-speed networks economically. The WINDS will realize ultra high-speed networking and demonstrate operability of satellite communication systems in high-speed internet. NICT is now developing high-speed satellite communication system for WINDS. High-speed TDMA burst modem with high performance TPC error correction is underdevelopment. Up to the DAC on the transmitter and from the ADC on the receiver, all modem functions are performed in the digital processing technology. Burst modem has been designed for a user data rate up to 1244 Mbps. NICT is developing the digital terminal as a user interface and a network controller for this earth station. High compatibility with the Internet will be provided.

  6. Beginnings of Satellite Navigation

    Directory of Open Access Journals (Sweden)

    Miljenko Solarić

    2008-05-01

    Full Text Available The first satellite navigation system called the Navy Navigation Satellite System (NNSS or TRANSIT was planned in the USA in 1958. It consisted of 5-6 artificial Earth satellites, was set in motion for the USA military in 1964, and in 1967 for civilian purposes. The frequency shift of received radio waves emitted from the satellite and caused by the Doppler effect was measured. The TRANSIT satellite speed of approaching or moving away was derived from that; the TRANSIT satellites emmited also their own coordinates. Then the ship's position was determined by an intersection of three hyperboloids, which were determined from differences of distances in three time intervals. Maintenance of this navigation system was stopped in 1996, but it is still being used in the USA Navy for exploring the ionosphere. Furthermore, results of Doppler measurements in international projects at the Hvar Observatory from 1982 and 1983. This was the first time in Croatia and the former country that the coordinates of the Hvar Observatory were determined in the unique world coordinate system WGS'72. The paper ends with a brief representation of the Tsiklon Doppler navigation system produced in the former Soviet Union, and there is a list of some of numerous produced and designed satellite navigation systems.Ključne riječi

  7. Potential Interference to the Deep Space Network Stations in Spain from NPOESS in the 25.5- to 27.0-GHz Band

    Science.gov (United States)

    Tsou, H.

    2008-08-01

    A new Instituto Nacional de Tecnica Aeroespacial (INTA) station, located about 70 km east of the Deep Space Network (DSN) Madrid complex (Robledo), is planned to support National Polar-orbiting Operational Environmental Satellite System (NPOESS) satellites. The 26.7-GHz NPOESS Ka-band downlink to this proposed station can potentially interfere with the DSN Madrid station that may support the future lunar and Sun-Earth Lagrange point missions operating in the 25.5- to 27.0-GHz band. A preliminary compatibility analysis has been conducted to assess the potential impact to the DSN Madrid complex from the NPOESS Ka-band downlink to the planned INTA station.

  8. Tracking on non-active collaborative objects from San Fernando Laser station

    Science.gov (United States)

    Catalán, Manuel; Quijano, Manuel; Cortina, Luis M.; Pazos, Antonio A.; Martín-Davila, José

    2016-04-01

    The Royal Observatory of the Spanish Navy (ROA) works on satellite geodesy from the early days of the space age, when the first artificial satellite tracking telescope was installed in 1958: the Baker-Nunn camera. In 1975 a French satellite Laser ranging (SLR) station was installed and operated at ROA . Since 1980, ROA has been operating this instrument which was upgraded to a third generation and it is still keep into a continuous update to reach the highest level of operability. Since then ROA has participated in different space geodesy campaigns through the International Laser Service Stations (ILRS) or its European regional organization (EUROLAS), tracking a number of artificial satellites types : ERS, ENVISAT, LAGEOS, TOPEX- POSEIDON to name but a few. Recently we opened a new field of research: space debris tracking, which is receiving increasing importance and attention from international space agencies. The main problem is the relatively low accuracy of common used methods. It is clear that improving the predicted orbit accuracy is necessary to fulfill our aims (avoiding unnecessary anti-collision maneuvers,..). Following results obtained by other colleagues (Austria, China, USA,...) we proposed to share our time-schedule using our satellite ranging station to obtain data which will make orbital elements predictions far more accurate (sub-meter accuracy), while we still keep our tracking routines over active satellites. In this communication we report the actions fulfill until nowadays.

  9. The rise and fall of COMSAT technology, business, and government in satellite communications

    CERN Document Server

    Whalen, D

    2014-01-01

    Satellite communications grosses over 100 billion annually and is heading toward 200 billion. COMSAT started all of this in 1963 when it was organized in compliance with the Communications Satellite Act of 1962. COMSAT was responsible for choosing geosynchronous earth orbit (GEO), forming INTELSAT, and generally promoting the technological change that saw satellite power increase from the 40 watts of Early Bird (INTELSAT I) to the almost 10 kilowatts of INTELSAT IX; earth station antennas were reduced from 30 meters to 1 meter. The business of satellite communications was expanded to mobile co

  10. Photochemical Assessment Monitoring Stations (PAMS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Photochemical Assessment Monitoring Stations (PAMS). This file provides information on the numbers and distribution (latitude/longitude) of air monitoring sites...

  11. The Calern atmospheric turbulence station

    Science.gov (United States)

    Chabé, Julien; Ziad, Aziz; Fantéï-Caujolle, Yan; Aristidi, Éric; Renaud, Catherine; Blary, Flavien; Marjani, Mohammed

    2016-07-01

    From its long expertise in Atmospheric Optics, the Observatoire de la Côte d'Azur and the J.L. Lagrange Laboratory have equipped the Calern Observatory with a station of atmospheric turbulence measurement (CATS: Calern Atmospheric Turbulence Station). The CATS station is equipped with a set of complementary instruments for monitoring atmospheric turbulence parameters. These new-generation instruments are autonomous within original techniques for measuring optical turbulence since the first meters above the ground to the borders of the atmosphere. The CATS station is also a support for our training activities as part of our Masters MAUCA and OPTICS, through the organization of on-sky practical works.

  12. Laser ranging ground station development

    Science.gov (United States)

    Faller, J. E.

    1973-01-01

    The employment of ground to conduct radar range measurements of the lunar distance is discussed. The advantages of additional ground stations for this purpose are analyzed. The goals which are desirable for any new type of ranging station are: (1) full time availability of the station for laser ranging, (2) optimization for signal strength, (3) automation to the greatest extent possible, (4) the capability for blind pointing, (5) reasonable initial and modest operational costs, and (6) transportability to enhance the value of the station for geophysical purposes.

  13. Application for the Tape Station

    CERN Document Server

    Solero, A

    2003-01-01

    The Tape Station is used as an Isolde facility to observe the variations of intensity and the lifespan of certain isotopes. A Siemens Simatic FM-352-5 module controls the Tape Station in a PLC system then a DSC controls the PLC, which will be controlled the Tape station program. During the Isolde consolidation project, the Tape Station has been rebuilt, and the control system has been fully integrated in the PS control. Finally, a new application has been written in JAVA Development kit 1.4 and the PS Java environment. The main purpose of this note is to explain how to use this program.

  14. Intercultural Mediation

    OpenAIRE

    Dragos Marian Radulescu; Denisa Mitrut

    2012-01-01

    The Intercultural Mediator facilitates exchanges between people of different socio-cultural backgrounds and acts as a bridge between immigrants and national and local associations, health organizations, services and offices in order to foster integration of every single individual. As the use mediation increases, mediators are more likely to be involved in cross-cultural mediation, but only the best mediators have the opportunity to mediate cross border business disputes or international poli...

  15. Trends In Satellite Communication

    Science.gov (United States)

    Poley, William A.; Stevens, Grady H.; Stevenson, Steven M.; Lekan, Jack; Arth, Clifford H.; Hollansworth, James E.; Miller, Edward F.

    1988-01-01

    Report assesses trends in satellite communication from present to year 2010. Examines restrictions imposed by limited spectrum resource and technology needs created by trends. Personal communications, orbiting switchboards, and videophones foreseen.

  16. Domestic Communication Satellites

    Science.gov (United States)

    Horowitz, Andrew

    1974-01-01

    A discussion of the Federal Communications Commission's new policy on domestic satellites in light of our 1) military and economic history; 2) corporate interests; 3) citizen surveillance; and 4) media control. (HB)

  17. Handbook of satellite applications

    CERN Document Server

    Madry, Scott; Camacho-Lara, Sergio

    2013-01-01

    Top space experts from around the world have collaborated to produce this comprehensive, authoritative, and clearly illustrated reference guide to the fast growing, multi-billion dollar field of satellite applications and space communications. This handbook, done under the auspices of the International Space University based in France, addresses not only system technologies but also examines market dynamics, technical standards and regulatory constraints. The handbook is a completely multi-disciplinary reference book that covers, in an in-depth fashion, the fields of satellite telecommunications, Earth observation, remote sensing, satellite navigation, geographical information systems, and geosynchronous meteorological systems. It covers current practices and designs as well as advanced concepts and future systems. It provides a comparative analysis of the common technologies and design elements for satellite application bus structures, thermal controls, power systems, stabilization techniques, telemetry, com...

  18. Biological satellite Kosmos-936

    Science.gov (United States)

    Vedeshin, L. A.

    1978-01-01

    A description is given of physiological experiments performed on the biological satellite Kosmos-936. Other experiments to determine the electrostatic and dielectric responses to the effects of cosmic radiation are discussed.

  19. Small Satellite Transporter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The primary objective is to determine whether this small satellite transporter is capable of transporting at least four 6U CubeSats is possible for a given set of...

  20. The BDS iGMAS RIOS station at Observatório Nacional, Rio de Janeiro

    Science.gov (United States)

    Humberto Andrei, Alexandre; Song, Shuli; Junqueira, Selma; Beauvalet, Laurene

    2016-07-01

    GNSS navigation satellites are currently being developed by all major players in the science and technology scene, to compete with the GPS system. Because their applications span many different areas, from traffic and cargo control, to geodesy and seismic monitoring, it is required to assess the coherence between the different constellations. BDS is the GNSS system currently developed in China. Its first generation of satellites consisted of 3 geostationnary satellites allowing geolocalisation in China only. In addition to these satellites, other satellites have been launched in geostationnary and geosynchronous orbits, as well as satellites orbiting with a classical GNSS semi-major axis. With these additions, the BDS system possesses 19 operating satellites, and though the system is mostly efficient for geolocalisation in Asia, the satellites are also visible in other parts of the globe. In parallel to the development of the BDS constellation, China has launched the iGMAS (International GNSS Monitoring and Assessment Service) project to develop a global tracking network of multi-GNSS geodetic receivers. One of the goals of this project is to evaluate the efficiency of the BDS constellation as well as the efficiency of the receivers developed by the Chinese laboratories. As part of the Brazilian program COSBAN leaded by the Foreign Affairs Ministry to foster up the science and technology partnership with China, materialized by the collaboration between the Shanghai Astronomical Observatory/CAS and the Observatório Nacional/MCTI, in Rio de Janeiro. Through it the RIOS-iGMAS station was installed at Observatório Nacional, where the RJEP GNSS station already operates as part of the Brazilian reference system. Thus at the Observatório Nacional can be observed satellites from any constellation with both systems of reception, leading to a direct, efficient way to compare the results obtained for each network. In this communication we focus on the determination of the

  1. DFH-3 Satellite Platform

    Institute of Scientific and Technical Information of China (English)

    RenShufang

    2005-01-01

    The DFH-3 satellite platform is designed and developed by China Academy of Space Technology (CAST). It is a medium capability communications satellite platform. The platform adopts threeaxis attitude stabilization control system, having solar array output power of 1.7kW by the end of its design lifetime of 8 years. Its mass is 2100kg with payload capacity of 220kg.

  2. The Archimedes satellite system

    Science.gov (United States)

    Taylor, Stuart C.; Shurvinton, William D.

    1992-03-01

    Archimedes is a satellite system conceived by the European Space Agency (ESA) to effectively serve the European market for Mobile Radio Services (MRS). This paper describes the requirements and technical design of the Archimedes satellite system. The underlying assumptions and trade-offs behind the design are detailed and the design is compared and contrasted against alternative design solutions, both technically and economically. A path forward for the development of the system is indicated.

  3. ASTRID II satellit projekt

    DEFF Research Database (Denmark)

    Jørgensen, John Leif; Primdahl, Fritz

    1997-01-01

    The report describes the instruments developed for the Swedish micro satellite "ASTRID II". Specifications of the two instruments realized under this contract, a Stellar Compass and a CSC magnetometer are given follwed by a description of the project status and plan.......The report describes the instruments developed for the Swedish micro satellite "ASTRID II". Specifications of the two instruments realized under this contract, a Stellar Compass and a CSC magnetometer are given follwed by a description of the project status and plan....

  4. Satellite formation. II

    Science.gov (United States)

    Harris, A. W.

    1978-01-01

    A satellite formation model is extended to include evolution of planetary ring material and elliptic orbital motion. In this model the formation of the moon begins at a later time in the growth of the earth, and a significant fraction of the lunar material is processed through a circumterrestrial debris cloud where volatiles might have been lost. Thus, the chemical differences between the earth and moon are more plausibly accounted for. Satellites of the outer planets probably formed in large numbers throughout the growth of those planets. Because of rapid inward evolution of the orbits of small satellites, the present satellite systems represent only satellites formed in the last few percent of the growths of their primaries. The rings of Saturn and Uranus are most plausibly explained as the debris of satellites disrupted within the Roche limit. Because such a ring would collapse onto the planet in the course of any significant further accretion by the planet, the rings must have formed very near or even after the conclusion of accretion.

  5. Mobile satellite news gathering (SNG) system; Soko SNG (Satellite News Gathering) shasaikyoku

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    Commercialization was made for broadcasting stations on a mobile station system capable of capturing a satellite automatically while the system is moving. Its feature is the enhanced tracking accuracy as a result of using the Company's original null-sensor (see Note), and detecting and controlling intersecting polarized waves of reference signals from the satellite. The material for transmission is digitally transmitted by MPEG2, making it possible to transmit more data than by conventional systems. The system is being used for live broadcasting of marathon races and emergency news broadcasting. It is expected that the system may be applied to applications other than broadcasting stations, such as automobiles and ships. (Note: A null-sensor is a unit used for adjusting antenna directions for an SNG transmitter. It uses IF receiving signals of H/V polarized waves of parabolic antenna as an input, and outputs the main polarized wave level and the intersecting polarized wave level.) (translated by NEDO)

  6. Stanwell power station project

    Energy Technology Data Exchange (ETDEWEB)

    Mills, David R; J Dey, Christopher [University of Sidney, Sidney (Australia); Morrison, Graham L [University of New South Wales, Sidney (Australia)

    2000-07-01

    This paper describes the Compact Linear Fresnel Reflector (CLFR) being developed for installation at the Stanwell power station in Queensland Australia. Stanwell Corporation Limited (SCL). Solahart International, Solsearch Pty. Ltd. And the universities of Sidney and New South Wales are cooperating in the project, and this first plant being partly funded by the Australian Greenhouse Office. The solar plant will be attached to a 1440 MW(e) coal fired plant. The 17000 m{sup 2} array will be the largest array in Australia, producing a peak of 13 MW of thermal energy which will offset the use of coal in the generation of electricity. It will use direct steam generation and will feed either steam or hot water at 265 Celsius degrees directly into the power station preheating cycle. The CLFR system, first developed by the University of Sidney and Solsearch Pty. Ltd., is simple and offers small reflector size, low structural cost, fixed receiver geometry. Initial installed plant costs are approximately US$1000 per kWe, but this includes the effect of high up-front design costs and the cost should drop substantially in the second and subsequent plants. [Spanish] Proyecto de la Planta Electrica Stanwell este articulo describe el Reflector Lineal Compacto Fresnel (CLFR, siglas en ingles) que se esta desarrollando para la instalacion de la planta electrica Stanwell en Queensland, Australia. La Corporacion Stanwell Limited (SCL), Solahart International, Solsearch Pty. Ltd., las universidades de Sidney y de New South Wales estan cooperando en este proyecto, y esta primera planta esta parcialmente auspiciada por la Australian Greenhouse Office. La planta solar sera anexa a una planta de carbon de 1440 MW(e). Este arreglo de 17000 m{sup 2} sera el mayor en Australia y producira un maximo de 13 MW en energia termica la cual contrarrestara el uso del carbon en la generacion de electricidad. Utilizara generacion con vapor directo y alimentara ya sea vapor o agua caliente a 265 grados

  7. CHINA LAUNCHES NEW SCIENTIFIC SATELLITE

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    China on Sept. 27, 2004 launched a scientific satellite atop a Long March 2D carrier rocket from Jiuquan Satellite Launch Center in Gansu province. 10 minutes after the launch, the satellite entered a preset orbit and is running sound at the orbit. It is the 20th recoverable satellite for scientific and technological

  8. Multivariate Regression Approach To Integrate Multiple Satellite And Tide Gauge Data For Real Time Sea Level Prediction

    DEFF Research Database (Denmark)

    Cheng, Yongcun; Andersen, Ole Baltazar; Knudsen, Per

    2010-01-01

    The Sea Level Thematic Assembly Center in the EUFP7 MyOcean project aims at build a sea level service for multiple satellite sea level observations at a European level for GMES marine applications. It aims to improve the sea level related products to guarantee the sustainability and the quality o...... stations with satellite altimetry....

  9. Dependent surveillance through an experimental satellite data link system

    Science.gov (United States)

    Cobley, G. A.

    The development and testing of an experimental dependent aircraft-surveillance system using a satellite data link is reported. In this system, the aircraft position is determined onboard using GPS or inertial navigation, enclosed in a message block using a data-link system, and transmitted to an Inmarsat GEO communication satellites; the ground station receives and analyzes the data to keep constant track of the aircraft position. The hardware implementation and the results of demonstrations performed on flights from Iowa to Wisconsin and the North Atlantic are discussed, and diagrams and maps are provided.

  10. Search and rescue satellite-aided tracking system

    Science.gov (United States)

    Trudell, B.; Gutwein, J. M.; Vollmers, R.; Wammer, D.

    1980-10-01

    The objective of Sarsat is to demonstrate that satellites can greatly facilitate the monitoring, detection, and location of distress incidents alerted by Emergency Locator Transmitters (ELTs) and Emergency Position Indicating Radio Beacons (EPIRBs) carried on commercial, military, and general aviation aircraft and some marine vessels. The detection and location will be accomplished by relaying, via satellite, ELT/EPIRB distress information to ground stations, which will complete the data processing and forward alert and position location data to rescue coordination services. This paper presents a Sarsat system description and a summary of Coast Guard and USAF objectives for the initial demonstration and evaluation tests of Sarsat.

  11. The improved CFDAMA protocol with predictive request strategy via satellite

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xi; JIA Shi-lou

    2005-01-01

    The novel satellite Multiple Access scheme called Combined Free/Demand Assignment Multiple Access-Predictive Request (CFDAMA-PR) is proposed in this paper. In the CFDAMA-PR scheme, the ground station requests the demand assignment slots by predicting the positive varying trend of the traffic source. The delay performances between CFDAMA-PR and CFDAMA-RR (Round Robin request) schemes were compared by computer simulation. Simulations were carried out with the Interrupted Poisson Process (IPP) and the Interrupted Fluid Process (IFP) traffic models. Simulation results demonstrate that compared to CFDAMA-RR protocol, the CFDAMA-PR scheme achieves a better delay/throughput of satellite channel.

  12. Automation and robotics for the Space Station - The influence of the Advanced Technology Advisory Committee

    Science.gov (United States)

    Nunamaker, Robert R.; Willshire, Kelli F.

    1988-01-01

    The reports of a committee established by Congress to identify specific systems of the Space Station which would advance automation and robotics technologies are reviewed. The history of the committee, its relation to NASA, and the reports which it has released are discussed. The committee's reports recommend the widespread use of automation and robotics for the Space Station, a program for technology development and transfer between industries and research and development communities, and the planned use of robots to service and repair satellites and their payloads which are accessible from the Space Station.

  13. Data Collection Satellite Application in Precision Agriculture

    Science.gov (United States)

    Durào, O.

    2002-01-01

    Agricultural Instrumentation Research Center, Brazilian Agricultural Research Corporation; Space Programs Brazil launched in 1993 its first satellite partially built and entirely designed, integrated, tested and operated in the country. It was the SCD-1 satellite, a small (115 kg. and an octagonal prism with 80 cm. height and an external diameter of 100 cm.) with a payload transponder that receives data from ground platforms spread all over the country (including its sea shore). These data are then retransmitted to a receiving station at every satellite pass. Data collected and received are processed at Data Collection Mission Center for distribution via internet at most 30 min after the satellite pass. The ground platforms are called PCD's and differ in the parameters measured according to its purpose and location. Thus, they are able to measure temperature, rain level, wind direction, solar radiation, carbon monoxide as well as many others, beyond its own location. SCD- 1 had a nominal designed life of one year, but is still functioning. It is a LEO satellite with inclination of 25°. In 1998, the country launched SCD-2, with the same purpose, but in phase with SCD-1 . Other differences were a higher index of Brazilian made components and an active attitude control subsystem for the spin rate provided by the magnetic torque coils (these in accordance with a development strategy previously planned). In 1999 the country launched in cooperation with China a remote sensing satellite (mass of 1.4 ton.) called CBERS-1. This satellite is sun synchronous (98° inclination) and also carries a transponder for data collection/transmission as a secondary payload. Thus, the country has now three satellites with data collection/transmission capabilities, two in low inclination phased orbits and one in polar orbit, providing a nice coverage both geographical and temporal not only to its territory but also to other regions of the world.. At first there were not too many PCD

  14. Position surveillance using one active ranging satellite and time-of-arrival of a signal from an independent satellite

    Science.gov (United States)

    Anderson, R. E.; Frey, R. L.; Lewis, J. R.

    1980-01-01

    Position surveillance using one active ranging/communication satellite and the time-of-arrival of signals from an independent satellite was shown to be feasible and practical. A towboat on the Mississippi River was equipped with a tone-code ranging transponder and a receiver tuned to the timing signals of the GOES satellite. A similar transponder was located at the office of the towing company. Tone-code ranging interrogations were transmitted from the General Electric Earth Station Laboratory through ATS-6 to the towboat and to the ground truth transponder office. Their automatic responses included digital transmissions of time-of-arrival measurements derived from the GOES signals. The Earth Station Laboratory determined ranges from the satellites to the towboat and computed position fixes. The ATS-6 lines-of-position were more precise than 0.1 NMi, 1 sigma, and the GOES lines-of-position were more precise than 1.6 NMi, 1 sigma. High quality voice communications were accomplished with the transponders using a nondirectional antenna on the towboat. The simple and effective surveillance technique merits further evaluation using operational maritime satellites.

  15. Sighting the International Space Station

    Science.gov (United States)

    Teets, Donald

    2008-01-01

    This article shows how to use six parameters describing the International Space Station's orbit to predict when and in what part of the sky observers can look for the station as it passes over their location. The method requires only a good background in trigonometry and some familiarity with elementary vector and matrix operations. An included…

  16. Naval Weapons Station Earle Reassessment

    Science.gov (United States)

    2013-12-01

    surveys for their Section 110 compliance: Architectural Resources Survey, Naval Weapons Station Earle, Monmouth County, New Jersey (Louis Berger 1999...text within brackets. Berger Report 1999 Architectural Resources Survey, Naval Weapons Station Earle, Monmouth County, New Jersey (Louis Berger... architectural treatment of buildings at NWS Earle: a traditional vernacular theme with minimal decorative detailing. This so-called minimal traditional

  17. Sighting the International Space Station

    Science.gov (United States)

    Teets, Donald

    2008-01-01

    This article shows how to use six parameters describing the International Space Station's orbit to predict when and in what part of the sky observers can look for the station as it passes over their location. The method requires only a good background in trigonometry and some familiarity with elementary vector and matrix operations. An included…

  18. Satellite Communications for ATM

    Science.gov (United States)

    Shamma, Mohammed A.

    2003-01-01

    This presentation is an overview on Satellite Communication for the Aeronautical Telecommunication Management (ATM) research. Satellite Communications are being considered by the FAA and NASA as a possible alternative to the present and future ground systems supporting Air Traffic Communications. The international Civil Aviation Organization (ICAO) have in place Standards and Recommended Practices (SARPS) for the Aeronautical Mobile Satellite Services (AMSS) which is mainly derived from the pre-existing Inmarsat service that has been in service since the 1980s. The Working Group A of the Aeronautical Mobile Communication Panel of ICAO has also been investigating SARPS for what is called the Next Generation Satellite Service (NGSS) which conforms less to the Inmarsat based architecture and explores wider options in terms of satellite architectures. Several designs are being proposed by Firms such as Boeing, ESA, NASA that are geared toward full or secondary usage of satellite communications for ATM. Satellite communications for ATM can serve several purposes ranging from primary usage where ground services would play a minimal backup role, to an integrated solution where it will be used to cover services, or areas that are less likely to be supported by the proposed and existing ground infrastructure. Such Integrated roles can include usage of satellite communications for oceanic and remote land areas for example. It also can include relieving the capacity of the ground network by providing broadcast based services of Traffic Information Services messages (TIS-B), or Flight Information Services (FIS-B) which can take a significant portion of the ground system capacity. Additionally, satellite communication can play a backup role to support any needs for ground replacement, or additional needed capacity even after the new digital systems are in place. The additional bandwidth that can be provided via satellite communications can also open the door for many new

  19. Satellite cells from dystrophic muscle retain regenerative capacity

    Directory of Open Access Journals (Sweden)

    Luisa Boldrin

    2015-01-01

    Full Text Available Duchenne muscular dystrophy is an inherited disorder that is characterized by progressive skeletal muscle weakness and wasting, with a failure of muscle maintenance/repair mediated by satellite cells (muscle stem cells. The function of skeletal muscle stem cells resident in dystrophic muscle may be perturbed by being in an increasing pathogenic environment, coupled with constant demands for repairing muscle. To investigate the contribution of satellite cell exhaustion to this process, we tested the functionality of satellite cells isolated from the mdx mouse model of Duchenne muscular dystrophy. We found that satellite cells derived from young mdx mice contributed efficiently to muscle regeneration within our in vivo mouse model. To then test the effects of long-term residence in a dystrophic environment, satellite cells were isolated from aged mdx muscle. Surprisingly, they were as functional as those derived from young or aged wild type donors. Removing satellite cells from a dystrophic milieu reveals that their regenerative capacity remains both intact and similar to satellite cells derived from healthy muscle, indicating that the host environment is critical for controlling satellite cell function.

  20. Experimental Satellite 2 Successfully Launched

    Institute of Scientific and Technical Information of China (English)

    LiuJie

    2004-01-01

    Small satellite Experimental Satellite 2 (SY-2) was launched by LM-2C launch vehicle from Xichang Satellite Launch Center on Nov. 18, 2004. Later the satellite entered the preset sun-synchronous orbit, which is 700 kilometers above the earth. The launch was the eighthmission this year by China Aerospace Science and Technology Corporation(CASC), which aims to test the technology of the satellite, conduct survey and monitoring of the land and resources and geographical environment on a trial basis.

  1. China's Meteorological Satellite Application System

    Institute of Scientific and Technical Information of China (English)

    Zhang Jiashen

    2008-01-01

    @@ China's meteorological satellite program consists of five systems,namely the satellite system,the launch vehicle system,the launch center system,TT&C and the ground application system.The satellite system consists of FengYun (FY) polar orbiting series and FY geostationary series,which are launched by LM launch vehicles from Taiyan Satellite Launch Center (TSLC) and Xichang Satellite Launch Center (XSLC) respectively.

  2. Practical experience of telehealth between an Antarctic station and Japan.

    Science.gov (United States)

    Ohno, Giichiro; Watanabe, Kentaro; Okada, Yutaka; Higuchi, Kazuo

    2012-12-01

    The Japanese Antarctic Research Expedition (JARE) has had a presence in Antarctica since 1956. The Syowa station is 15,000 km from Japan and evacuation of patients is impossible during the winter months. From 1956 to 2003, a total of 4932 telemedical consultations were undertaken, i.e. every member of the station needed an average of 4 medical consultations each winter. Forty five percent of the consultations were surgical or orthopaedic cases, 23% were for internal medicine and 12% were for dental problems. In the early 1980s, satellite radio-telephony was found to be useful for consultations, but did not have the ability to transmit medical pictures. Email was transmitted by the International Mobile Satellite Organization (INMARSAT) but the connection was only available every 2 hours and the maximum message size was 100 kByte. In 2004, the International Telecommunications Satellite (INTELSAT) system made a connection constantly available, and increased the maximum message size to 10 MByte. Transmission of still and moving pictures became possible. Scheduled consultations are performed monthly. A doctor in Japan can ask the patient questions and perform a proxy examination with the assistance of the Antarctic doctor. Real-time telemedicine is very effective in orthopaedic and surgical cases, skin, eye and dental troubles. Still pictures are more effective for understanding in detail skin and eye problems. Emergency consultations are effective if adequate consulting staff are available.

  3. An Integrated Approach for Site Selection of Snow Measurement Stations

    Directory of Open Access Journals (Sweden)

    Bahram Saghafian

    2016-11-01

    Full Text Available Snowmelt provides a reliable water resource for meeting domestic, agricultural, industrial and hydropower demands. Consequently, estimating the available snow water equivalent is essential for water resource management of snowy regions. Due to the spatiotemporal variability of the snowfall pattern in mountainous areas and difficult access to high altitudes areas, snow measurement is one of the most challenging hydro-meteorological data collection efforts. Development of an optimum snow measurement network is a complex task that requires integration of meteorological, hydrological, physiographical and economic studies. In this study, site selection of snow measurement stations is carried out through an integrated process using observed snow course data and analysis of historical snow cover images from National Oceanic Atmospheric Administration Advanced Very High Resolution Radiometer (NOAA-AVHRR at both regional and local scales. Several important meteorological and hydrological factors, such as monthly and annual rainfall distribution, spatial distribution of average frequency of snow observation (FSO for two periods of snow falling and melting season, as well as priority contribution of sub-basins to annual snowmelt runoff are considered for selecting optimum station network. The FSO maps representing accumulation of snowfall during falling months and snowpack persistence during melting months are prepared in the GIS based on NOAA-AVHRR historical snow cover images. Basins are partitioned into 250 m elevation intervals such that within each interval, establishment of new stations or relocation/removing of the existing stations were proposed. The decision is made on the basis of the combination of meteorological, hydrological and satellite information. Economic aspects and road access constraints are also considered in determining the station type. Eventually, for the study area encompassing a number of large basins in southwest of Iran

  4. Spacecraft Modularity for Serviceable Satellites

    Science.gov (United States)

    Rossetti, Dino; Keer, Beth; Panek, John; Reed, Benjamin; Cepollina, Frank; Ritter, Robert

    2015-01-01

    Satellite servicing has been a proven capability of NASA since the first servicing missions in the 1980s with astronauts on the space shuttle. This capability enabled the on-orbit assembly of the International Space Station (ISS) and saved the Hubble Space Telescope (HST) mission following the discovery of the flawed primary mirror. The effectiveness and scope of servicing opportunities, especially using robotic servicers, is a function of how cooperative a spacecraft is. In this paper, modularity will be presented as a critical design aspect for a spacecraft that is cooperative from a servicing perspective. Different features of modularity are discussed using examples from HST and the Multimission Modular Spacecraft (MMS) program from the 1980s and 1990s. The benefits of modularity will be presented including those directly related to servicing and those outside of servicing including reduced costs and increased flexibility. The new Reconfigurable Operational spacecraft for Science and Exploration (ROSE) concept is introduced as an affordable implementation of modularity that provides cost savings and flexibility. Key aspects of the ROSE architecture are discussed such as the module design and the distributed avionics architecture. The ROSE concept builds on the experience from MMS and due to its modularity, would be highly suitable as a future client for on-orbit servicing.

  5. Satellite-Friendly Protocols and Standards

    Science.gov (United States)

    Koudelka, O.; Schmidt, M.; Ebert, J.; Schlemmer, H.; Kastner, S.; Riedler, W.

    2002-01-01

    We are currently observing a development unprecedented with other services, the enormous growth of the Internet. Video, voice and data applications can be supported via this network in high quality. Multi-media applications require high bandwidth which may not be available in many areas. When making proper use of the broadcast feature of a communications satellite, the performance of the satellite-based system can compare favourably to terrestrial solutions. Internet applications are in many cases highly asymmetric, making them very well suited to applications using small and inexpensive terminals. Data from one source may be used simultaneously by a large number of users. The Internet protocol suite has become the de-facto standard. But this protocol family in its original form has not been designed to support guaranteed quality of service, a prerequisite for real-time, high quality traffic. The Internet Protocol has to be adapted for the satellite environment, because long roundtrip delays and the error behaviour of the channel could make it inefficient over a GEO satellite. Another requirement is to utilise the satellite bandwidth as efficiently as possible. This can be achieved by adapting the access system to the nature of IP frames, which are variable in length. In the framework of ESA's ARTES project a novel satellite multimedia system was developed which utilises Multi-Frequency TDMA in a meshed network topology. The system supports Quality of Service (QoS) by reserving capacity with different QoS requirements. The system is centrally controlled by a master station with the implementation of a demand assignment (DAMA) system. A lean internal signalling system has been adopted. Network management is based on the SNMP protocol and industry-standard network management platforms, making interfaces to standard accounting and billing systems easy. Modern communication systems will have to be compliant to different standards in a very flexible manner. The

  6. The Architecture of the Laser Communications Relay Demonstration Ground Stations: An Overview

    Science.gov (United States)

    Moores, John D.; Wilson, Keith E.

    2013-01-01

    NASA's Laser Communication Relay Demonstration (LCRD) will be NASA's first long-duration demonstration of laser communications (lasercom) in space, providing geosynchronous-satellite-hosted bidirectional relay services between two Earth ground stations. LCRD will leverage and enhance existing ground stations. Ground Station 1 (GS-1) will leverage the Optical Communications Telescope Laboratory (OCTL) built by JPL, while Ground Station 2 (GS-2) will leverage the Lunar Laser Communications Demonstration (LLCD) Ground Terminal (LLGT) built by MIT Lincoln Laboratory. While each ground system has unique telescopes and integrated optics, many of the backend subsystems (e.g., communications, environmental monitoring, control, user simulators) will be common to both terminals. Here we provide an overview of the architecture of the LCRD ground stations, and the planned enhancements to the existing facilities.

  7. Astronaut Franklin R. Chang-Diaz, payload commander, is busy at the pilots station during operations

    Science.gov (United States)

    1996-01-01

    Astronaut Franklin R. Chang-Diaz, payload commander, is busy at the pilots station during operations to deploy the Tethered Satellite System (TSS). His five crew mates (out of frame) were also on the flight deck, of the Earth-orbiting Space Shuttle Columbia, during the busy deployment activities.

  8. SLR Station Recovery, Center of Frame Motion, and Time Varying Gravity

    Science.gov (United States)

    Zelensky, Nikita P.; Lemoine, Frank G.; Chinn, Douglas S.; Melachroinos, Stavros; Wiser Beall, Jennifer; Larson, Jordan D.

    2012-01-01

    Weekly station position estimates, beginning with 1993, are derived from the ITRF2008-based SLR processing of up to four satellites: Lageos 1, Lageos2, Starlette, and Stella. Helmert parameters obtained from c omparison of weekly SLR station positions and the a-priori SLRF2008 station complement are evaluated for geocenter motion and scale. Two me thods for modeling time varying gravity are employed in the SLR satel lite POD processing, with GGM03S serving as the static gravity field. Both methods forward model atmosphere gravity derived from 6-hour ECM WF pressure data. The standard approach applies an annual 20x20 field estimated from 4 years of GRACE data, and the IERS2003 recommended linear rates for C20, C30, C40, C21, and S21. The alternate approach us es a new set of low-order/degree 4x4 coefficients estimated weekly fr om SLR & DORIS processing to 10 satellites from 1993-2012. This exper imental tvg4x4 model has been shown to improve the TOPEX, Jason-1, and Jason-2 altimeter satellite orbits,. In this paper we apply the more detailed time-variable gravity modeling to the SLR satellite POD pro cessing and subsequent reference frame analyses. For this study we will evaluate the orbit differences (periodic and secular) for the satel lites concerned, characterize the impact on the station coordinate solutions, and the impact on reference frame parameters (geocenter and s cale).

  9. Satellite co-locations as a link between SLR, GPS and Low Earth Orbiting (LEO) satellites

    Science.gov (United States)

    Melachroinos, S. A.; Lemoine, F. G.; Chinn, D. S.; Nicolas, J. B.; Zelensky, N. P.; Wimert, J.; Radway, Y.

    2013-12-01

    The procedure applied for the determination of the International Terrestrial Reference Frame (ITRF) requires the combination of all four major techniques of Space Geodesy. This combination is only possibly realized by the introduction of the local-ties between co-located techniques. A local-tie is the lever arm vector between the marker points on the sites where two or more space geodesy instruments operate. The local ties are used as additional observations with proper variances. They are usually derived from local surveys using either classical geodesy or the global navigation satellite systems (GNSS). The Global Positioning System (GPS) plays a major role in the ITRF combination by linking together all the other three techniques SLR, DORIS and VLBI (Altamimi and Collilieux 2009). However, discrepancies between local ties and space geodesy estimates are well known although the reasons for these discrepancies are often not clear. These discrepancies could be either due to errors in local ties and in coordinate estimates or in both. In this study, we use the tracking to G05-35 and G06-36 and one LEO by SLR sites and their combined orbits, earth rotation parameters (ERPs) and station positions in order to establish space-based co-location ties on the stations. The LEO satellite used in this experiment is Jason-2, which carries both GPS and SLR. Therefore from the data-processing point of view the LEO satellite is used as a fast moving station (Thaller et al. 2011). Jason-2 is also equipped with DORIS, but it will be included into another combined analysis. Subsequently, we compare the consistency of our space-based co-locations to the ones from ITRF08 and SLRF08 - IGb08 solutions.

  10. Radiofrequency testing of satellite segment of simulated 30/20 GHz satellite communications system

    Science.gov (United States)

    Leonard, R. F.; Kerczewski, R.

    1985-01-01

    A laboratory communications system has been developed that can serve as a test bed for the evaluation of advanced microwave (30/20 GHz) components produced under NASA technology programs. The system will ultimately permit the transmission of a stream of high-rate (220 Mbps) digital data from the originating user, through a ground terminal, through a hardware-simulated satellite, to a receiving ground station, to the receiving user. This report contains the results of radiofrequency testing of the satellite portion of that system. Data presented include output spurious responses, attainable signal-to-noise ratios, a baseline power budget, usable frequency bands, phase and amplitude response data for each of the frequency bands, and the effects of power level variation.

  11. Remote Synchronization Experiments for Quasi-Senith Satellite System Using Current Geostationary Satellites

    Directory of Open Access Journals (Sweden)

    Toshiaki Iwata

    2010-01-01

    Full Text Available The remote synchronization system for the onboard crystal oscillator (RESSOX realizes accurate synchronization between an atomic clock at a ground station and the QZSS onboard crystal oscillator, reduces overall cost and satellite power consumption, as well as onboard weight and volume, and is expected to have a longer lifetime than a system with onboard atomic clocks. Since a QZSS does not yet exist, we have been conducting synchronization experiments using geostationary earth orbit satellites (JCSAT-1B or Intelsat-4 to confirm that RESSOX is an excellent system for timing synchronization. JCSAT-1B, the elevation angle of which is 46.5 degrees at our institute, is little affected by tropospheric delay, whereas Intelsat-4, the elevation angle of which is 7.9 degrees, is significantly affected. The experimental setup and the results of uplink experiments and feedback experiments using mainly Intelsat-4 are presented. The results show that synchronization within 10 ns is realized.

  12. Satellite-based detection of global urban heat-island temperature influence

    Science.gov (United States)

    Gallo, K.P.; Adegoke, Jimmy O.; Owen, T.W.; Elvidge, C.D.

    2002-01-01

    This study utilizes a satellite-based methodology to assess the urban heat-island influence during warm season months for over 4400 stations included in the Global Historical Climatology Network of climate stations. The methodology includes local and regional satellite retrievals of an indicator of the presence green photosynthetically active vegetation at and around the stations. The difference in local and regional samples of the normalized difference vegetation index (NDVI) is used to estimate differences in mean air temperature. Stations classified as urban averaged 0.90??C (N. Hemisphere) and 0.92??C (S. Hemisphere) warmer than the surrounding environment on the basis of the NDVI-derived temperature estimates. Additionally, stations classified as rural averaged 0.19??C (N. Hemisphere) and 0.16??C (S. Hemisphere) warmer than the surrounding environment. The NDVI-derived temperature estimates were found to be in reasonable agreement with temperature differences observed between climate stations. The results suggest that satellite-derived data sets can be used to estimate the urban heat-island temperature influence on a global basis and that a more detailed analysis of rural stations and their surrounding environment may be necessary to assure that temperature trends derived from assumed rural environments are not influenced by changes in land use/land cover. Copyright 2002 by the American Geophysical Union.

  13. Recent Korean R&D in Satellite Communications

    Science.gov (United States)

    Lee, Ho-Jin; Kim, Jae Moung; Lee, Byung-Seub; Lee, Han; Ryoo, Jang-Soo

    The R&D in satellite communications in Korea has been driven mainly by KCC (Korea Communications Commission) but in a small scale compared to Korea space development program organized by MEST (Ministry of Education, Science and Technology). Public and civilian satcom sector R&D has been led mainly by ETRI with small/medium companies contrary to rare investment in private sector while military sector R&D has been orchestrated by ADD with defense industry. By the COMS (Communication, Ocean and Meteorological Satellite) experimental Ka-band payload, Korea pursues a space qualification of own technology for national infrastructure evolution as well as industrialization of space R&D results. Once COMS launched and space qualified in 2009, subsequent application experiments and new technology R&D like UHDTV will entail service and industry promotion. The payload technology is expected for the next Korean commercial satellites or for new OBP satellites. The COMS ground control system and GNSS ground station technologies are under development for COMS operation and enhanced GNSS services along with advent of Galileo respectively. Satellite broadband mobile VSAT based on DVB-S2/RCS (+M) and low profile tracking antennas have been developed for trains, ships, and planes. While APSI is developing GMR-1 based Thuraya handset functions, ETRI is designing IMT-Advanced satellite radio interface for satellite and terrestrial dual-mode handheld communication system like Japanese STICS, with universities' satellite OFDM researches. A 21GHz Ka-band higher-availability scalable HD broadcasting technology and SkyLife's hybrid satellite IPTV technology are being developed. In near term Korea will extend R&D programs to upgrade the space communication infrastructure for universal access to digital opportunity and safer daily life from disaster, and to promote space green IT industrialization, national security, and space resources sovereign. Japanese stakeholders are invited to establish

  14. Small satellites for global coverage: Potential and limits

    Science.gov (United States)

    Sandau, Rainer; Brieß, Klaus; D'Errico, Marco

    2010-11-01

    There is an increasing need for Earth Observation (EO) missions to meet the information requirements in connection with Global Change Studies. Small and cost-effective missions are powerful tools to flexibly react to information requirements with space-borne solutions. Small satellite missions can be conducted relatively quickly and inexpensively by using commercial off-the-shelf-technologies, or they can be enhanced by using advanced technologies. A new class of advanced small satellites, including autonomously operating "intelligent" satellites may be created, opening new fields of application. The increasing number of small satellites and their applications drive developments in the fields of small launchers, small ground station networks, cost-effective data distribution methods, and cost-effective management and quality assurance procedures. There are many advantages of small satellite missions, like more frequent mission opportunities, a faster return of data, larger variety of missions, more rapid expansion of the technical and/or scientific knowledge base, greater involvement of small industry, feasibility by universities and others. This paper deals with general trends in the field of small satellite missions for Earth observation. Special attention is given to the potential of spatial, spectral, and temporal resolution of small satellite based systems. Examples show small satellites offer also the unique possibility to install affordable constellations to provide good daily coverage of the globe and/or allow us to observe dynamic phenomena. The facts and examples given in this paper lead to the conclusion: Small satellites are already powerful tools for monitoring global, regional and local phenomena. In the future, their application spectrum will even broaden based on the ongoing development in many areas of technology and observation techniques.

  15. The Italian contribution to the CSES satellite

    Science.gov (United States)

    Conti, Livio

    2016-04-01

    parameters and stability of Van Allen belt are constantly modified by natural non-seismic and man-made processes. Therefore, in order to identify seismo-associated perturbations, it is needed to reject the "normal" background effects of the e.m. emissions due to: geomagnetic storms, tropospheric phenomena, and artificial sources (such as power lines, VLF transmitters, HF stations, etc.). Currently, the only available large database is that collected by the Demeter satellite and by rare observations made by some previous space missions, non-dedicated to this purpose. The CSES satellite aims at continuing the exploration started by Demeter with advanced multi-parametric measurements. The configuration of the CSES sensors foresees measurements of energetic particle fluxes, ionospheric plasma parameters and electromagnetic fields, in a wide range of energy and frequencies. The main sensors onboard the satellite are: the HEPD (High Energy Particle Detector) developed by the Italian participants, and the following Chinese sensors: LEPD (Low Energy Particle Detector), LP (Langmuir Probes), IDM (Ion Drift Meter), ICM (Ion Capture Meter), RPA (Retarding Potential Analyzer), EFD (Electric Field Detectors) developed in collaboration with Italian team, HPM (High Precision Magnetometer) and SCM (Search-Coil Magnetometer). The research activity is at an advanced phase, being the various payloads already built and, right now, an intense activity is going on for calibration of the various sensors. In particular, the Italian payload HEPD is under test at the laboratories of the National Institute for Nuclear Physics (INFN) and the Chinese payloads LP, IDM, ICM, RPA and EFD are tested at the INAF-IAPS "Plasma Chamber" in Rome, which is a facility where the response of the sensors, and their compatibility with ionospheric plasma, can be verified in environmental conditions very similar to those met by the satellite in orbit.

  16. 47 CFR 97.207 - Space station.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Space station. 97.207 Section 97.207... SERVICE Special Operations § 97.207 Space station. (a) Any amateur station may be a space station. A holder of any class operator license may be the control operator of a space station, subject to...

  17. 47 CFR 97.109 - Station control.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Station control. 97.109 Section 97.109... SERVICE Station Operation Standards § 97.109 Station control. (a) Each amateur station must have at least one control point. (b) When a station is being locally controlled, the control operator must be at...

  18. Solar Power Satellites

    CERN Document Server

    Flournoy, Don M

    2012-01-01

    Communication satellites are a $144 billion industry. Is there any space-based industry that could possibly beat that market? 'Solar Power Satellites' shows why and how the space satellite industry will soon begin expanding its market from relaying signals to Earth to generating energy in space and delivering it to the ground as electricity. In all industrialized nations, energy demand is growing exponentially. In the developing world, the need for energy is as basic as food and water. The Sun's energy is available everywhere, and it is non-polluting. As business plans demonstrate its technical feasibility, commercial potential, and environmental acceptability, every country on Earth will look to space for the power it needs.

  19. ESA's satellite communications programme

    Science.gov (United States)

    Bartholome, P.

    1985-02-01

    The developmental history, current status, and future plans of the ESA satellite-communications programs are discussed in a general survey and illustrated with network diagrams and maps. Consideration is given to the parallel development of national and European direct-broadcast systems and telecommunications networks, the position of the European space and electronics industries in the growing world market, the impact of technological improvements (both in satellite systems and in ground-based networks), and the technological and commercial advantages of integrated space-terrestrial networks. The needs for a European definition of the precise national and international roles of satellite communications, for maximum speed in implementing such decisions (before the technology becomes obsolete), and for increased cooperation and standardization to assure European equipment manufacturers a reasonable share of the market are stressed.

  20. AVS on satellite

    Science.gov (United States)

    Zhao, Haiwu; Wang, Guozhong; Hou, Gang

    2005-07-01

    AVS is a new digital audio-video coding standard established by China. AVS will be used in digital TV broadcasting and next general optical disk. AVS adopted many digital audio-video coding techniques developed by Chinese company and universities in recent years, it has very low complexity compared to H.264, and AVS will charge very low royalty fee through one-step license including all AVS tools. So AVS is a good and competitive candidate for Chinese DTV and next generation optical disk. In addition, Chinese government has published a plan for satellite TV signal directly to home(DTH) and a telecommunication satellite named as SINO 2 will be launched in 2006. AVS will be also one of the best hopeful candidates of audio-video coding standard on satellite signal transmission.

  1. Satellite Control Laboratory

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Bak, Thomas

    2001-01-01

    The Satellite Laboratory at the Department of Control Engineering of Aalborg University (SatLab) is a dynamic motion facility designed for analysis and test of micro spacecraft. A unique feature of the laboratory is that it provides a completely gravity-free environment. A test spacecraft...... is suspended on an air bearing, and rotates freely in 3 degrees of freedom. In order to avoid any influence of the gravitational force the centre of mass of the satellite is placed in the geometric centre of the air bearing by an automatic balancing system. The test spacecraft is equipped with a three......-axis magnetometer, three piezoelectric gyros, and four reaction wheels in a tetrahedron configuration. The operation of the spacecraft is fully autonomous. The data flow between the transducers and the onboard computer placed physically outside the satellite is provided by a radio link. The purpose...

  2. Biotechnology opportunities on Space Station

    Science.gov (United States)

    Deming, Jess; Henderson, Keith; Phillips, Robert W.; Dickey, Bernistine; Grounds, Phyllis

    1987-01-01

    Biotechnology applications which could be implemented on the Space Station are examined. The advances possible in biotechnology due to the favorable microgravity environment are discussed. The objectives of the Space Station Life Sciences Program are: (1) the study of human diseases, (2) biopolymer processing, and (3) the development of cryoprocessing and cryopreservation methods. The use of the microgravity environment for crystal growth, cell culturing, and the separation of biological materials is considered. The proposed Space Station research could provide benefits to the fields of medicine, pharmaceuticals, genetics, agriculture, and industrial waste management.

  3. Communication Systems through Artificial Earth Satellites (Selected Pages)

    Science.gov (United States)

    1987-02-05

    POX Fs (8.2.11) is 0(F) dF If on input of weighing circuit fluctuation noise with uniform spectrum acts, spectral power density in numerator and...Possibly also realization MV with asynchronous operation of terrestrial stations, that we will designate through MVA . In the case MVA each terrestrial...according to the frequcrncy. With MVA through receiving-transmitting equipment of satellite into some tiMe intervals simultaneous possible passage of signals

  4. The international maritime satellite communications system INMARSAT (Handbook)

    Science.gov (United States)

    Zhilin, Viktor A.

    The organization and services provided by the INMARSAT satellite communications system are summarized. The structure and operation of the system are described with reference to transmission line parameters, frequency assignment, signals, telex communications, electrical parameters of communication channels, modulation, synchronization, and methods of protection against errors in the transmission of discrete messages. The discussion also covers the principal components of the INMARSAT system and the operation of ship-based stations.

  5. GPS satellite surveying

    CERN Document Server

    Leick, Alfred; Tatarnikov, Dmitry

    2015-01-01

    THE MOST COMPREHENSIVE, UP-TO-DATE GUIDE ON GPS TECHNOLOGY FOR SURVEYING Three previous editions have established GPS Satellite Surveying as the definitive industry reference. Now fully updated and expanded to reflect the newest developments in the field, this Fourth Edition features cutting-edge information on GNSS antennas, precise point positioning, real-time relative positioning, lattice reduction, and much more. Expert authors examine additional tools and applications, offering complete coverage of geodetic surveying using satellite technologies. The past decade has seen a major evolut

  6. Declassified intelligence satellite photographs

    Science.gov (United States)

    ,

    1998-01-01

    Recently declassified photographs from spy satellites are an important addition to the record of the Earth?s land surface held by the U.S. Geological Survey (USGS). More than 800,000 high-resolution photos taken between 1959 through 1972 were made available by Executive Order of the President. The collection is held at the USGS EROS Data Center, near Sioux Falls, S. Dak., and are offered for public sale. For some purposes in earth science studies, these photos extend the record of changes in the land surface another decade back in time from the advent of the Landsat earth-observing satellite program.

  7. Oceanography from satellites

    Science.gov (United States)

    Wilson, W. S.

    1981-01-01

    It is pointed out that oceanographers have benefited from the space program mainly through the increased efficiency it has brought to ship operations. For example, the Transit navigation system has enabled oceanographers to compile detailed maps of sea-floor properties and to more accurately locate moored subsurface instrumentation. General descriptions are given of instruments used in satellite observations (altimeter, color scanner, infrared radiometer, microwave radiometer, scatterometer, synthetic aperture radar). It is pointed out that because of the large volume of data that satellite instruments generate, the development of algorithms for converting the data into a form expressed in geophysical units has become especially important.

  8. Satellite oceanography - The instruments

    Science.gov (United States)

    Stewart, R. H.

    1981-01-01

    It is pointed out that no instrument is sensitive to only one oceanographic variable; rather, each responds to a combination of atmospheric and oceanic phenomena. This complicates data interpretation and usually requires that a number of observations, each sensitive to somewhat different phenomena, be combined to provide unambiguous information. The distinction between active and passive instruments is described. A block diagram illustrating the steps necessary to convert data from satellite instruments into oceanographic information is included, as is a diagram illustrating the operation of a radio-frequency radiometer. Attention is also given to the satellites that carry the various oceanographic instruments.

  9. Integrated Satellite-HAP Systems

    DEFF Research Database (Denmark)

    Cianca, Ernestina; De Sanctis, Mauro; De Luise, Aldo

    2005-01-01

    for an efficient hybrid terrestrial-satellite communication system. Two integrated HAP-satellite scenarios are presented, in which the HAP is used to overcome some of the shortcomings of satellite- based communications. Moreover, it is shown that the integration of HAPs with satellite systems can be used......Thus far, high-altitude platform (HAP)-based systems have been mainly conceived as an alternative to satellites for complementing the terrestrial network. This article aims to show that HAP should no longer be seen as a competitor technology by investors of satellites, but as a key element...

  10. Spatial Cloud Detection and Retrieval System for Satellite Images

    Directory of Open Access Journals (Sweden)

    Ayman Nasr

    2013-01-01

    Full Text Available In last the decade we witnessed a large increase in data generated by earth observing satellites. Hence, intelligent processing of the huge amount of data received by hundreds of earth receiving stations, with specific satellite image oriented approaches, presents itself as a pressing need. One of the most important steps in earlier stages of satellite image processing is cloud detection. Satellite images having a large percentage of cloud cannot be used in further analysis. While there are many approaches that deal with different semantic meaning, there are rarely approaches that deal specifically with cloud detection and retrieval. In this paper we introduce a novel approach that spatially detect and retrieve clouds in satellite images using their unique properties .Our approach is developed as spatial cloud detection and retrieval system (SCDRS that introduce a complete framework for specific semantic retrieval system. It uses a Query by polygon (QBP paradigm for the content of interest instead of using the more conventional rectangular query by image approach. First, we extract features from the satellite images using multiple tile sizes using spatial and textural properties of cloud regions. Second, we retrieve our tiles using a parametric statistical approach within a multilevel refinement process. Our approach has been experimentally validated against the conventional ones yielding enhanced precision and recall rates in the same time it gives more precise detection of cloud coverage regions.

  11. The First Chinese Ocean Color Satellite HY-1A

    Institute of Scientific and Technical Information of China (English)

    PAN Delu; HE Xianqiang

    2004-01-01

    HY-1A is China's first ocean color satellite, and was launched on 15 May 2002as a piggyback satellite on the FY-1D satellite using the Long March rocket.There are two sensors on the satellite: China's Ocean Color and Temperature Scanner (COCTS), and the CCD Coastal Zone Imager (CZI). In the report,first, the properties and characteristics of HY-1A are briefly introduced; Second, the quality and availability of the data are evaluated by the mean of the Complex Signal Noise Ratio (CSNR) which is simulated theoretically; Third,the received HY-1A data are compared with SeaSTAR data to understand the accuracy of radiance measurement by the HY-1A; Finally, the remote sensing products of ocean color and temperature are mapped by HY-1A to study its application potentiality. The results show that the HY-1A has a latent capability for the application of marine environment detection, the management and protection of marine resources, and the furthering of national rights and interests.Meanwhile, some modifications are proposed for the next ocean satellite, suchas adding the case of tilt scanning, modification of the CCD element uniformity,and adding more ocean satellite receiving stations.

  12. Monte Carlo simulations of precise timekeeping in the Milstar communication satellite system

    Science.gov (United States)

    Camparo, James C.; Frueholz, R. P.

    1995-01-01

    The Milstar communications satellite system will provide secure antijam communication capabilities for DOD operations into the next century. In order to accomplish this task, the Milstar system will employ precise timekeeping on its satellites and at its ground control stations. The constellation will consist of four satellites in geosynchronous orbit, each carrying a set of four rubidium (Rb) atomic clocks. Several times a day, during normal operation, the Mission Control Element (MCE) will collect timing information from the constellation, and after several days use this information to update the time and frequency of the satellite clocks. The MCE will maintain precise time with a cesium (Cs) atomic clock, synchronized to UTC(USNO) via a GPS receiver. We have developed a Monte Carlo simulation of Milstar's space segment timekeeping. The simulation includes the effects of: uplink/downlink time transfer noise; satellite crosslink time transfer noise; satellite diurnal temperature variations; satellite and ground station atomic clock noise; and also quantization limits regarding satellite time and frequency corrections. The Monte Carlo simulation capability has proven to be an invaluable tool in assessing the performance characteristics of various timekeeping algorithms proposed for Milstar, and also in highlighting the timekeeping capabilities of the system. Here, we provide a brief overview of the basic Milstar timekeeping architecture as it is presently envisioned. We then describe the Monte Carlo simulation of space segment timekeeping, and provide examples of the simulation's efficacy in resolving timekeeping issues.

  13. Satellite orbit determination and gravity field recovery from satellite-to-satellite tracking

    Science.gov (United States)

    Wakker, K. F.; Ambrosius, B. A. C.; Leenman, H.

    1989-07-01

    Studies on satellite-to-satellite tracking (SST) with POPSAT (a geodetic satellite concept) and a ERS-class (Earth observation) satellite, a Satellite-to-Satellite Tracking (SST) gravity mission, and precise gravity field determination methods and mission requirements are reported. The first two studies primarily address the application of SST between the high altitude POPSAT and an ERS-class or GRM (Geopotential Research Mission) satellite to the orbit determination of the latter two satellites. Activities focussed on the determination of the tracking coverage of the lower altitude satellite by ground based tracking systems and by POPSAT, orbit determination error analysis and the determination of the surface forces acting on GRM. The third study surveys principles of SST, uncertainties of existing drag models, effects of direct luni-solar attraction and tides on orbit and the gravity gradient observable. Detailed ARISTOTELES (which replaced POPSAT) orbit determination error analyses were performed for various ground based tracking networks.

  14. Gravity Station Data for Portugal

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data total 3064 records. This data base was received in April 1997. Principal gravity parameters include Free-air Anomalies which have been...

  15. Interior Alaska Gravity Station Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data total 9416 records. This data base was received in March 1997. Principal gravity parameters include Free-air Anomalies which have been...

  16. Gravity Station Data for Spain

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The gravity station data total 28493 records. This data base was received in April 1997. Principal gravity parameters include Free-air Anomalies which have been...

  17. WVU Hydrogen Fuel Dispensing Station

    Energy Technology Data Exchange (ETDEWEB)

    Davis, William [West Virginia University Research Corporation, Morgantown, WV (United States)

    2015-09-01

    The scope of this project was changed during the course of the project. Phase I of the project was to construct a site similar to the site at Central West Virginia Regional Airport in Charleston, WV to show that duplication of the site was a feasible method of conducting hydrogen stations. Phase II of the project was necessitated due to a lack of funding that was planned for the development of the station in Morgantown. The US Department of Energy determined that the station in Charleston would be dismantled and moved to Morgantown and reassembled at the Morgantown site. This necessitated storage of the components of the station for almost a year at the NAFTC Headquarters which caused a number of issues with the equipment that will be discussed in later portions of this report. This report will consist of PHASE I and PHASE II with discussions on each of the tasks scheduled for each phase of the project.

  18. Non-Coop Station History (Unindexed)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Station history documentation for stations outside the US Cooperative Observer network. Documents should be compared with those in the Non-Coop Station History...

  19. Space stations systems and utilization

    CERN Document Server

    Messerschmid, Ernst

    1999-01-01

    The design of space stations like the recently launched ISS is a highly complex and interdisciplinary task. This book describes component technologies, system integration, and the potential usage of space stations in general and of the ISS in particular. It so adresses students and engineers in space technology. Ernst Messerschmid holds the chair of space systems at the University of Stuttgart and was one of the first German astronauts.

  20. Internationalization of the Space Station

    Science.gov (United States)

    Lottmann, R. V.

    1985-01-01

    Attention is given to the NASA Space Station system elements whose production is under consideration by potential foreign partners. The ESA's Columbus Program declaration encompasses studies of pressurized modules, unmanned payload carriers, and ground support facilities. Canada has expressed interest in construction and servicing facilities, solar arrays, and remote sensing facilities. Japanese studies concern a multipurpose experimental module concept. Each of these foreign investments would expand Space Station capabilities and lay the groundwork for long term partnerships.

  1. Gas Compressor Station Economic Optimization

    Directory of Open Access Journals (Sweden)

    Rainer Kurz

    2012-01-01

    Full Text Available When considering gas compressor stations for pipeline projects, the economic success of the entire operation depends to a significant extent on the operation of the compressors involved. In this paper, the basic factors contributing to the economics are outlined, with particular emphasis on the interaction between the pipeline and the compressor station. Typical scenarios are described, highlighting the fact that pipeline operation has to take into account variations in load.

  2. Gas Compressor Station Economic Optimization

    OpenAIRE

    2012-01-01

    When considering gas compressor stations for pipeline projects, the economic success of the entire operation depends to a significant extent on the operation of the compressors involved. In this paper, the basic factors contributing to the economics are outlined, with particular emphasis on the interaction between the pipeline and the compressor station. Typical scenarios are described, highlighting the fact that pipeline operation has to take into account variations in load.

  3. Conveying International Space Station Science

    Science.gov (United States)

    Goza, Sharon P.

    2017-01-01

    Over 1,000 experiments have been completed, and others are being conducted and planed on the International Space Station (ISS). In order to make the information on these experiments accessible, the IGOAL develops mobile applications to easily access this content and video products to convey high level concepts. This presentation will feature the Space Station Research Explorer as well as several publicly available video examples.

  4. Experimental study of mountain lee—waves by means of satellite photographs and aircraft measurements

    OpenAIRE

    Cruette, Denise

    2011-01-01

    This paper is a summary of a Ph.D. Thesis1 which was a systematic study of the influence of various meteorological factors on the occurrence and characteristics of mountain waves, more specifically of lee-waves of great horizontal extent. The data used are, beside classical meteorological informations, that given by satellite pictures completed by quasi-simultaneous measurements from planes or gliders. The analysis of many satellite pictures received at the french station of Lannion (Brittany...

  5. Theory of experimental location of ionospheric inhomogeneities at medium latitudes by satellite radioholography

    Energy Technology Data Exchange (ETDEWEB)

    Dubovoi, A.P.; Sinelnikov, V.M.

    1980-08-01

    A theory is developed for a quasiholographic experiment which uses a differential-phase signal derived from radio signals transmitted at two coherent frequencies to obtain information on ionospheric inhomogeneities in a plane connecting the ground station and a part of the satellite orbit. The method makes it possible to determine the size and location of small-scale inhomogeneities with a radius of 100-500 m from ground-based measurements of spaced satellite signals transmitted at sufficiently high coherent frequencies.

  6. Delay analysis for interlan traffic using two suitable TDMA satellite access schemes

    OpenAIRE

    Celandroni, Nedo; Ferro, Erina; Potort?, Francesco; Maral, Gerard

    1997-01-01

    This paper presents Faded Environments Effective Distributed Engineering Redundant Signalling (FEEDERS), an access scheme for sharing, in time division multiple access (TDMA) mode, the capacity of a satellite channel among a number of stations, on the basis of user demand, This scheme and its companion Distributed Allocation with Request In Fixed Slots (DRIFS), result from a study carried out by the authors on distributed-control protocols for geostationary satellite access. Both protocols de...

  7. An adaptive linearizer for 16-QAM transmission over non-linear satellite channels

    Science.gov (United States)

    Shanmugan, K. Sam; Ruggles, M. J.

    An adaptive nonlinear equalization scheme that consists of a predistorter located at the transmitting earth station and a linear equalizer at the receiving earth station is described. Algorithms for automatically adjusting the predistorter and the linear equalizer are presented. The effectiveness of the scheme is evaluated using simulations. It is shown that the scheme improves the performance of a 16-queued access memory system operating over a typical satellite channel by minimizing degradations in the signal as it is transmitted over a band-limited satellite channel.

  8. Satellite triangulation in Europe from WEST and ISAGEX data. [computer programs

    Science.gov (United States)

    Leick, A.; Arur, M.

    1975-01-01

    Observational data that was acquired during the West European Satellite Triangulation (WEST) program and the International Satellite Geodesy Experiment (ISAGEX) campaign was obtained for the purpose of performing a geometric solution to improve the present values of coordinates of the European stations in the OSU WN14 solutions, adding some new stations and assessing the quality of the WN14 solution with the help of the additional data available. The status of the data as received, the preprocessing required and the preliminary tests carried out for the initial screening of the data are described. The adjustment computations carried out and the results of the adjustments are discussed.

  9. Fade durations in satellite-path mobile radio propagation

    Science.gov (United States)

    Schmier, Robert G.; Bostian, Charles W.

    1986-01-01

    Fades on satellite to land mobile radio links are caused by several factors, the most important of which are multipath propagation and vegetative shadowing. Designers of vehicular satellite communications systems require information about the statistics of fade durations in order to overcome or compensate for the fades. Except for a few limiting cases, only the mean fade duration can be determined analytically, and all other statistics must be obtained experimentally or via simulation. This report describes and presents results from a computer program developed at Virginia Tech to simulate satellite path propagation of a mobile station in a rural area. It generates rapidly-fading and slowly-fading signals by separate processes that yield correct cumulative signal distributions and then combines these to simulate the overall signal. This is then analyzed to yield the statistics of fade duration.

  10. An Orbiting Standards Platform for communication satellite system RF measurements

    Science.gov (United States)

    Wallace, R. G.; Woodruff, J. J.

    1978-01-01

    The Orbiting Standards Platform (OSP) is a proposed satellite dedicated to performing RF measurements on space communications systems. It would consist of a quasi-geostationary spacecraft containing an ensemble of calibrated RF sources and field strength meters operating in several microwave bands, and would be capable of accurately and conveniently measuring critical earth station and satellite RF performance parameters, such as EIRP, gain, figure of merit (G/T), crosspolarization, beamwidth, and sidelobe levels. The feasibility and utility of the OSP concept has been under joint study by NASA, NBS, Comsat and NTIA. A survey of potential OSP users was conducted by NTIA as part of this effort. The response to this survey, along with certain trends in satellite communications system design, indicates a growing need for such a measurement service.

  11. The principle of the positioning system based on communication satellites

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    It is a long dream to realize the communication and navigation functionality in a satellite system in the world. This paper introduces how to establish the system, a positioning system based on communication satellites called Chinese Area Positioning System (CAPS). Instead of the typical navigation satellites, the communication satellites are configured firstly to transfer navigation signals from ground stations, and can be used to obtain service of the positioning, velocity and time, and to achieve the function of navigation and positioning. Some key technique issues should be first solved; they include the accuracy position determination and orbit prediction of the communication satellites, the measur- ing and calculation of transfer time of the signals, the carrier frequency drift in communication satellite signal transfer, how to improve the geometrical configuration of the constellation in the system, and the integration of navigation & communication. Several innovative methods are developed to make the new system have full functions of navigation and communication. Based on the development of crucial techniques and methods, the CAPS demonstration system has been designed and developed. Four communication satellites in the geosynchronous orbit (GEO) located at 87.5°E, 110.5°E, 134°E, 142°E and barometric altimetry are used in the CAPS system. The GEO satellites located at 134°E and 142°E are decommissioned GEO (DGEO) satellites. C-band is used as the navigation band. Dual frequency at C1=4143.15 MHz and C2=3826.02 MHz as well as dual codes with standard code (CA code and precision code (P code)) are adopted. The ground segment consists of five ground stations; the master station is in Lintong, Xi’an. The ground stations take a lot of responsibilities, including monitor and management of the operation of all system components, determination of the satellite position and prediction of the satellite orbit, accomplishment of the virtual atomic clock

  12. Satellite delivered cable television - A Warner-Amex experience

    Science.gov (United States)

    Stasi, D.; Setos, A.

    1984-03-01

    Operational aspects of the ground reception of C-band satellite transmissions by CATV operators are discussed. The current C-band network with 20 transmitters and 6000 receivers is shown to have been made possible by the relaxation of the earth-station licensing requirements, while economic factors have been responsible for the introduction of sophisticated and less sophisticated techniques to obtain 'adequate' picture quality with smaller antennas located in more difficult reception sites. The adoption of a quality standard of -18 dB C/I on the basis of empirical tests of viewer perception is considered reasonable, but further lowering of the standard (beyond -15 dB) is questioned. It is pointed out that antenna systems providing only minimal reception with 4-deg satellite spacing may be rendered useless by satellite video-traffic interference when 2-deg spacing is introduced over the next two years.

  13. Planning and Scheduling for Fleets of Earth Observing Satellites

    Science.gov (United States)

    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.

  14. Observations of artificial satellites

    Directory of Open Access Journals (Sweden)

    A. MAMMANO

    1964-06-01

    Full Text Available The following publication gives the results of photographic
    observations of artificial satellites made at Asiago during the second
    and third year of this programme. The fixed camera technique and that
    with moving film (the latter still in its experimental stage have been used.

  15. Experimental Satellite Quantum Communications.

    Science.gov (United States)

    Vallone, Giuseppe; Bacco, Davide; Dequal, Daniele; Gaiarin, Simone; Luceri, Vincenza; Bianco, Giuseppe; Villoresi, Paolo

    2015-07-24

    Quantum communication (QC), namely, the faithful transmission of generic quantum states, is a key ingredient of quantum information science. Here we demonstrate QC with polarization encoding from space to ground by exploiting satellite corner cube retroreflectors as quantum transmitters in orbit and the Matera Laser Ranging Observatory of the Italian Space Agency in Matera, Italy, as a quantum receiver. The quantum bit error ratio (QBER) has been kept steadily low to a level suitable for several quantum information protocols, as the violation of Bell inequalities or quantum key distribution (QKD). Indeed, by taking data from different satellites, we demonstrate an average value of QBER=4.6% for a total link duration of 85 s. The mean photon number per pulse μ_{sat} leaving the satellites was estimated to be of the order of one. In addition, we propose a fully operational satellite QKD system by exploiting our communication scheme with orbiting retroreflectors equipped with a modulator, a very compact payload. Our scheme paves the way toward the implementation of a QC worldwide network leveraging existing receivers.

  16. Perception via satellite

    Science.gov (United States)

    Robinove, Charles J.

    1970-01-01

    The earth resources observation satellite (EROS) program in the Department of the Interior is intended to gather and use data from satellites and aircraft on natural and man-made features of the earth's surface. Earth resources technology satellite will provide the EROS program with data for use in dealing with natural resource problems and understanding the interaction between man and the environment. Applications will include studies of tectonic features, hydrologic problems, location of fish schools, determination of the conditions of range land, mapping land use for urban planning, studies of erosion and change along coastlines and major streams, and inventories of land use and land forms. In addition, the ERTS data may be used for detecting forest and crop diseases and inventorying crops. The ERTS satellite will be in a polar, sun-synchronous orbit so that each point on the earth's surface will be sensed every 17 to 20 days, at the same time of day. Multispectral photography is being investigated for its usefulness in hydrology. Side-looking airborne radar has not yet been widely used in hydrologic studies, although it is an excellent tool for all-weather, day or night, coverage of large areas. Other techniques being investigated include passive microwave radiometry, ultraviolet and visible stimulated luminescence, and absorption spectroscopy.

  17. Satellite Photometric Error Determination

    Science.gov (United States)

    2015-10-18

    of nearly specular reflections from most solar panels. Our primary purpose in presenting these two plots is to demonstrate the usefulness of...than a transformation for stars because the spectral energy distribution of satellites can change with phase angle and is subject to specular

  18. Creating Better Satellite Conferences.

    Science.gov (United States)

    Horner, Tommy

    1998-01-01

    Presents four ways to improve broadcasts of company satellite conferences, including creative site selection (using facilities at educational institutions rather than hotel rooms); creative programming (using graphics and other interruptions to break up lectures or speeches); creative crew selection; and creative downlink site activities (to…

  19. Ocean surveillance satellites

    Science.gov (United States)

    Laurent, D.

    Soviet and U.S. programs involving satellites for surveillance of ships and submarines are discussed, considering differences in approaches. The Soviet program began with the Cosmos 198 in 1967 and the latest, the Cosmos 1400 series, 15 m long and weighing 5 tons, carry radar for monitoring ships and a nuclear reactor for a power supply. Other Soviet spacecraft carrying passive microwave sensors and ion drives powered by solar panels have recently been detonated in orbit for unknown reasons. It has also been observed that the Soviet satellites are controlled in pairs, with sequential orbital changes for one following the other, and both satellites then overflying the same points. In contrast, U.S. surveillance satellites have been placed in higher orbits, thus placing greater demands on the capabilities of the on-board radar and camera systems. Project White Cloud and the Clipper Bow program are described, noting the continued operation of the White Cloud spacecraft, which are equipped to intercept radio signals from surface ships. Currently, the integrated tactical surveillance system program has completed its study and a decision is expected soon.

  20. OMV With Satellite

    Science.gov (United States)

    1986-01-01

    This 1986 artist's concept shows the Orbital Maneuvering Vehicle (OMV) towing a satellite. As envisioned by Marshall Space Flight Center plarners, the OMV would be a remotely-controlled free-flying space tug which would place, rendezvous, dock, and retrieve orbital payloads.

  1. Advances in satellite oceanography

    Science.gov (United States)

    Brown, O. B.; Cheney, R. E.

    1983-01-01

    Technical advances and recent applications of active and passive satellite remote sensing techniques to the study of oceanic processes are summarized. The general themes include infrared and visible radiometry, active and passive microwave sensors, and buoy location systems. The surface parameters of sea surface temperature, windstream, sea state, altimetry, color, and ice are treated as applicable under each of the general methods.

  2. 47 CFR 80.107 - Service of private coast stations and marine-utility stations.

    Science.gov (United States)

    2010-10-01

    ...-utility stations. 80.107 Section 80.107 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED... Operating Procedures-Land Stations § 80.107 Service of private coast stations and marine-utility stations. A private coast station or a marine-utility station is authorized to transmit messages necessary for...

  3. 47 CFR 73.6016 - Digital Class A TV station protection of TV broadcast stations.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Digital Class A TV station protection of TV... Class A TV station protection of TV broadcast stations. Digital Class A TV stations must protect authorized TV broadcast stations, applications for minor changes in authorized TV broadcast stations filed...

  4. Cibola flight experiment satellite

    Science.gov (United States)

    Davies, P.; Liddle, Doug; Paffett, John; Sweeting, Martin; Curiel, A.; Sun, Wei; Eves, Stuart

    2004-11-01

    In order to achieve an "economy of scale" with respect to payload capacity the major trend in telecommunications satellites is for larger and larger platforms. With these large platforms the level of integration between platform and payload is increasing leading to longer delivery schedules. The typical lifecycle for procurement of these large telecommunications satellites is now 3-6 years depending on the level of non-recurring engineering needed. Surrey Satellite Technology Ltd (SSTL) has designed a low-cost platform aimed at telecommunications and navigation applications. SSTL's Geostationary Minisatellite Platform (GMP) is a new entrant addressing the lower end of the market with payloads up to 250kg requiring less than 1.5 kW power. The British National Space Centre through the MOSAIC Small Satellite Initiative supported the development of GMP. The main design goals for GMP are low-cost for the complete mission including launch and operations and a platform allowing flexible payload accommodation. GMP is specifically designed to allow rapid development and deployment with schedules typically between 1 and 2 years from contract signature to flight readiness. GMP achieves these aims by a modular design where the level of integration between the platform and payload is low. The modular design decomposes the satellite into three major components - the propulsion bay, the avionics bay and the payload module. Both the propulsion and avionics bays are reusable, largely unchanged, and independent of the payload configuration. Such a design means that SSTL or a 3rd party manufacturer can manufacture the payload in parallel to the platform with integration taking place quite late in the schedule. In July 2003 SSTL signed a contract for ESA's first Galileo navigation satellite known as GSTBV2/A. The satellite is based on GMP and ESA plan to launch it into a MEO orbit late in 2005. The second flight of GMP is likely to be in 2006 carrying a geostationary payload

  5. Astrometric positioning and orbit determination of geostationary satellites

    Science.gov (United States)

    Montojo, F. J.; López Moratalla, T.; Abad, C.

    2011-03-01

    In the project titled “Astrometric Positioning of Geostationary Satellite” (PASAGE), carried out by the Real Instituto y Observatorio de la Armada (ROA), optical observation techniques were developed to allow satellites to be located in the geostationary ring with angular accuracies of up to a few tenths of an arcsec. These techniques do not necessarily require the use of large telescopes or especially dark areas, and furthermore, because optical observation is a passive method, they could be directly applicable to the detection and monitoring of passive objects such as space debris in the geostationary ring.By using single-station angular observations, geostationary satellite orbits with positional uncertainties below 350 m (2 sigma) were reconstructed using the Orbit Determination Tool Kit software, by Analytical Graphics, Inc. This software is used in collaboration with the Spanish Instituto Nacional de Técnica Aeroespacial.Orbit determination can be improved by taking into consideration the data from other stations, such as angular observations alone or together with ranging measurements to the satellite. Tests were carried out combining angular observations with the ranging measurements obtained from the Two-Way Satellite Time and Frequency Transfer technique that is used by ROA’s Time Section to carry out time transfer with other laboratories. Results show a reduction of the 2 sigma uncertainty to less than 100 m.

  6. Air quality performed with satellite measurement within the QUITSAT project

    Science.gov (United States)

    Masieri, Samuele; Petritoli, Andrea; Premuda, Margarita; Kostadinov, Ivan; Bortoli, Daniele; Ravegnani, Fabrizio; Giovanelli, Giorgio

    Ground pollutants monitoring, using satellite observation, represents an interesting and high potential approach to air quality that could be inserted into Global monitoring systems. The QUITSAT Italian pilot project (air QUality with Integration of ground based and SAtellite measurements and chemical Transport and multiphase model), funded by the Italian Space Agency (ASI), proposes a new approach producing some interesting results in this frame. The approach focuses in the integration of the satellite observations (ENVISAT/SCIAMACHY and AURA/OMI) with the outputs of the GAMES (Gas Aerosol Modelling Evaluation System) chemical transport model, to provide the evaluation of the tropospheric profiles of some atmo-spheric compounds such as NO2 , O3 , HCHO and SO2 . This activity appears to be very useful to retrieve the surface concentration of trace gases from tropospheric columns of atmospheric compounds obtained with satellite instrumentation. The comparison with the in situ analyzer network over the Po' Valley shows a good correlation between the two data set. The corre-spondence can be improved taking into account also concentration gradients between different stations, classifying the ground base stations according to their rural or urban characteristics and considering the general orography of the ground. Results and methodology are presented and discussed.

  7. Defense Meteorological Satellite Program (DMSP)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Defense Meteorological Satellite Program (DMSP) satellites collect visible and infrared cloud imagery as well as monitoring the atmospheric, oceanographic,...

  8. Improvement and Simulation of an Autonomous Time Synchronization Algorithm for a Layered Satellite Constellation

    Directory of Open Access Journals (Sweden)

    Feijiang Huang

    2013-01-01

    Full Text Available Autonomous time synchronization for satellite constellations is a key technology to establish a constellation system time without the use of a ground station. The characteristics of satellite visibility time for layered satellite constellations containing geostationary earth orbit (GEO, inclined geosynchronous orbit (IGSO, and medium earth orbit (MEO satellites are simulated by establishing a visible satellite model. Based on the satellite visible simulation results for a layered constellation, this study investigates the autonomous time synchronization algorithm that corresponds to the layered constellation structure, analyzes the main error of the time synchronization algorithm, and proposes methods to improve the characteristics of satellite movement in the constellation. This study uses an improved two-way time synchronization algorithm for autonomous time synchronization in the GEO-MEO satellite layer of a layered satellite constellation. The simulation results show that in a condition with simulation errors, the time synchronization precision of this improved algorithm can be controlled within 5 ns and used in high-precision autonomous time synchronization between layered satellite constellations.

  9. DFH Satellite Co.,Ltd.

    Institute of Scientific and Technical Information of China (English)

    SunQing

    2004-01-01

    DFH Satellite Co.,Ltd. is a hi-tech enterprise founded and sponsored by China Aerospace Science and Technology Corporation(CASC) and one of CASC subsidiaries,China Academy of Space Technology (CAST). The company is mainly engaged in the research and development of small satellites and micro-satellites, Osystem designs and product development for satellite application projects as well as the international exchanges and cooperation.

  10. Telelibrary: Library Services via Satellite.

    Science.gov (United States)

    Liu, Rosa

    1979-01-01

    Investigates the provision of library services via satellite, explains briefly the operation and advantages of communication satellites, and discusses the various telecommunications equipment and services which, when coupled with satellite transmission, will enhance library activities. Demand trend projections for telecommunications services…

  11. Mobile satellite service for Canada

    Science.gov (United States)

    Sward, David

    1988-05-01

    The Mobile Satellite (MSAT) system and a special program designed to provide interim mobile satellite services (IMSS) during the construction phase of MSAT are described. A mobile satellite system is a key element in extending voice and and data telecommunications to all Canadians.

  12. Satellite Aerodynamics and Density Determination from Satellite Dynamic Response

    Science.gov (United States)

    Karr, G. R.

    1972-01-01

    The aerodynamic drag and lift properties of a satellite are first expressed as a function of two parameters associated with gas-surface interaction at the satellite surface. The dynamic response of the satellite as it passes through the atmosphere is then expressed as a function of the two gas-surface interaction parameters, the atmospheric density, the satellite velocity, and the satellite orientation to the high speed flow. By proper correlation of the observed dynamic response with the changing angle of attack of the satellite, it is found that the two unknown gas-surface interaction parameters can be determined. Once the gas-surface interaction parameters are known, the aerodynamic properties of the satellite at all angles of attack are also determined.

  13. 驻疆官兵成就动机对职业倦怠的影响:社会支持的中介作用%Effect of achievement motivation on job burnout of soldiers in military stations of Xinjiang:Mediating role of social support

    Institute of Scientific and Technical Information of China (English)

    丁魁; 秦天; 李权超

    2015-01-01

    Objective To explore the relationship between achievement motivation, social support and job burnout of soldiers in military stations of Xinjiang, and examine the mediating effect of social support.Methods A total of 757 soldiers from 2 militory stations in Xinjiang were recruited through random cluster sampling. The Achievement Motivation Scale, the Chinese Military Personnel Social Support Scale and the Job Burnout Scale were used to conduct investigation, and the correlation between achievement motivation, social support and job burnout was analyzed.Results (1)Each factor of job burnout showed positive correlations with the motivation of pursuing success(P﹤0.01), and negative correlations with the motivation of avoiding failure and the total score and each factor of social support (P﹤0.05,P﹤0.01). (2)Hierarchical regression analysis showed that social support played a mediating role between achievement motivation and job burnout. (3)Path analysis showed that the motivation of pursuing success had direct negative effect on the job burnout(-0.174). The motivation of pursuing success through social support had indigo effect on job burnout, accounting for 21.2% of total variation. The motivation of avoiding failure had direct positive effect on job burnout(0.286). The motivation of avoiding failure through social support had indigo effect on job burnout, accounting for 26.5% of total variation. Social support had direct negative effect on the job burnout(-0.468). Conclusions Achievement motivation and social support are important factors on job burnout. Social support played a partly mediating role between achievement motivation and job burnout.%目的:探讨驻疆官兵成就动机、社会支持与职业倦怠之间的关系,并检验社会支持的中介作用。方法采用随机整群抽样方法,选取驻疆官兵757名,运用成就动机量表、军人社会支持量表和军人职业倦怠量表进行调查,分析成就动机、社会支持

  14. Introduction to Space Station Freedom

    Science.gov (United States)

    Kohrs, Richard

    NASA field centers and contractors are organized to develop 'work packages' for Space Station Freedom. Marshall Space Flight Center and Boeing are building the U.S. laboratory and habitation modules, nodes, and environmental control and life support system; Johnson Space Center and McDonnell Douglas are responsible for truss structure, data management, propulsion systems, thermal control, and communications and guidance; Lewis Research Center and Rocketdyne are developing the power system. The Canadian Space Agency (CSA) is contributing a Mobile Servicing Center, Special Dextrous Manipulator, and Mobile Servicing Center Maintenance Depot. The National Space Development Agency of Japan (NASDA) is contributing a Japanese Experiment Module (JEM), which includes a pressurized module, logistics module, and exposed experiment facility. The European Space Agency (ESA) is contributing the Columbus laboratory module. NASA ground facilities, now in various stages of development to support Space Station Freedom, include: Marshall Space Flight Center's Payload Operations Integration Center and Payload Training Complex (Alabama), Johnson Space Center's Space Station Control Center and Space Station Training Facility (Texas), Lewis Research Center's Power System Facility (Ohio), and Kennedy Space Center's Space Station Processing Facility (Florida). Budget appropriations impact the development of the Space Station. In Fiscal Year 1988, Congress appropriated only half of the funds that NASA requested for the space station program ($393 million vs. $767 million). In FY 89, NASA sought $967 million for the program, and Congress appropriated $900 million. NASA's FY 90 request was $2.05 billion compared to an appropriation of $1.75 billion; the FY 91 request was $2.45 billion, and the appropriation was $1.9 billion. After NASA restructured the Space Station Freedom program in response to directions from Congress, the agency's full budget request of $2.029 billion for Space Station

  15. Current Trends and Challenges in Satellite Laser Ranging

    Science.gov (United States)

    Appleby, Graham M.; Bianco, Giuseppe; Noll, Carey E.; Pavlis, Erricos C.; Pearlman, Michael R.

    2016-12-01

    Satellite Laser Ranging (SLR) is used to measure accurately the distance from ground stations to retro-reflectors on satellites and on the Moon. SLR is one of the fundamental space-geodetic techniques that define the International Terrestrial Reference Frame (ITRF), which is the basis upon which many aspects of global change over space, time, and evolving technology are measured; with VLBI the two techniques define the scale of the ITRF; alone the SLR technique defines its origin (geocenter). The importance of the reference frame has recently been recognized at the inter-governmental level through the United Nations, which adopted in February 2015 the Resolution "Global Geodetic Reference Frame for Sustainable Development." Laser Ranging provides precision orbit determination and instrument calibration and validation for satellite-borne altimeters for the better understanding of sea level change, ocean dynamics, ice mass-balance, and terrestrial topography. It is also a tool to study the dynamics of the Moon and fundamental constants and theories. With the exception of the currently in-orbit GPS constellation, all GNSS satellites now carry retro-reflectors for improved orbit determination, harmonization of reference frames, and in-orbit co-location and system performance validation; the next generation of GPS satellites due for launch from 2019 onwards will also carry retro-reflectors. The ILRS delivers weekly realizations that are accumulated sequentially to extend the ITRF and the Earth Orientation Parameter series with a daily resolution. SLR technology continues to evolve towards the next-generation laser ranging systems and it is expected to successfully meet the challenges of the GGOS2020 program for a future Global Space Geodetic Network. Ranging precision is improving as higher repetition rate, narrower pulse lasers, and faster detectors are implemented within the network. Automation and pass interleaving at some stations is expanding temporal coverage and

  16. The principle of the positioning system based on communication satellites

    Institute of Scientific and Technical Information of China (English)

    AI GuoXiang; SHI HuLi; WU HaiTao; LI ZhiGang; GUO Ji

    2009-01-01

    It is a long dream to realize the communication and navigation functionality in a satellite system in the world.This paper introduces how to establish the system,a positioning system based on communication satellites called Chinese Area Positioning System (CAPS).Instead of the typical navigation satelIites,the communication satellites are configured firstly to transfer navigation signals from ground stations,and can be used to obtain service of the positioning,velocity and time,and to achieve the function of navigation and positioning.Some key technique issues should be first solved; they include the accuracy position determination and orbit prediction of the communication satellites,the measuring and calculation of transfer time of the signals,the carrier frequency drift in communication satellite ignal transfer,how to improve the geometrical configuration of the constellation in the system,and the integration of navigation & communication.Several innovative methods are developed to make the new system have full functions of navigation and communication.Based on the development of crucial techniques and methods,the CAPS demonstration system has been designed and developed.Four communication satellites in the geosynchronous orbit (GEO) located at 87.5°E,110.5°E,134°E,142°E and barometric altimetry are used in the CAPS system.The GEO satellites located at 134°E and 142°E re decommissioned GEO (DGEO) satellites.C-band is used as the navigation band.Dual frequency at C1=4143.15 MHz and C2=3826.02 MHz as well as dual codes with standard code (CA code and precision code (P code)) are adopted.The ground segment consists of five ground stations; the master station is in Lintong,Xi'an.The ground stations take a lot of responsibilities,including monitor and management of the operation of all system components,determination of the satellite position and prediction of the satellite orbit,accomplishment of the virtual atomic clock measurement,transmission and receiving

  17. Thematic mapping from satellite imagery

    CERN Document Server

    Denègre, J

    2013-01-01

    Thematic Mapping from Satellite Imagery: A Guidebook discusses methods in producing maps using satellite images. The book is comprised of five chapters; each chapter covers one stage of the process. Chapter 1 tackles the satellite remote sensing imaging and its cartographic significance. Chapter 2 discusses the production processes for extracting information from satellite data. The next chapter covers the methods for combining satellite-derived information with that obtained from conventional sources. Chapter 4 deals with design and semiology for cartographic representation, and Chapter 5 pre

  18. Cooperative and cognitive satellite systems

    CERN Document Server

    Chatzinotas, Symeon; De Gaudenzi, Riccardo

    2015-01-01

    Cooperative and Cognitive Satellite Systems provides a solid overview of the current research in the field of cooperative and cognitive satellite systems, helping users understand how to incorporate state-of-the-art communication techniques in innovative satellite network architectures to enable the next generation of satellite systems. The book is edited and written by top researchers and practitioners in the field, providing a comprehensive explanation of current research that allows users to discover future technologies and their applications, integrate satellite and terrestrial systems

  19. Direct Measurements of Laser Communication Point-Ahead Angles from the ARTEMIS Geostationary Satellite Through Clouds

    Science.gov (United States)

    Kuzkov, V.; Sodnik, Z.; Kuzkov, S.

    2017-01-01

    Laser experiments with ARTEMIS geostationary satellite have been performed in partly cloudy weather using the developed system for the telescope. It has been found that the part of the laser beam is observed simultaneously at the points in direction of the velocity vector where the satellite would arrive at when the laser light reaches the telescope. These results agree with the theory of relativity for light aberration in transition from fixed to moving coordinate system.Observation results open the way for research and development of systems to compensate atmospheric turbulence in laser communications between ground stations and satellites through the atmosphere.

  20. Direct Measurements of Laser Communication Point-Ahead Angles from the Artemis Geostationary Satellite Through Clouds

    Directory of Open Access Journals (Sweden)

    Kuzkov, V.P.

    2017-01-01

    Full Text Available Laser experiments with ARTEMIS geostationary satellite have been performed in partly cloudy weather using the developed system for the telescope. It has been found that the part of the laser beam is observed simultaneously at the points in direction of the velocity vector where the satellite would arrive at when the laser light reaches the telescope. These results agree with the theory of relativity for light aberration in transition from fixed to moving coordinate system. Observation results open the way for research and development of systems to compensate atmospheric turbulence in laser communications between ground stations and satellites through the atmosphere.

  1. Satellite Control Laboratory

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Bak, Thomas

    2001-01-01

    The Satellite Laboratory at the Department of Control Engineering of Aalborg University (SatLab) is a dynamic motion facility designed for analysis and test of micro spacecraft. A unique feature of the laboratory is that it provides a completely gravity-free environment. A test spacecraft...... is suspended on an air bearing, and rotates freely in 3 degrees of freedom. In order to avoid any influence of the gravitational force the centre of mass of the satellite is placed in the geometric centre of the air bearing by an automatic balancing system. The test spacecraft is equipped with a three...... of the laboratory is to conduct dynamic tests of the control and attitude determination algorithms during nominal operation and in abnormal conditions. Further it is intended to use SatLab for validation of various algorithms for fault detection, accommodation and supervisory control. Different mission objectives...

  2. Declassified Intelligence Satellite Photographs

    Science.gov (United States)

    ,

    2008-01-01

    Declassified photographs from U.S. intelligence satellites provide an important worldwide addition to the public record of the Earth's land surface. This imagery was released to the National Archives and Records Administration (NARA) and the U.S. Geological Survey (USGS) in accordance with Executive Order 12951 on February 23, 1995. The NARA has the original declassified film and a viewing copy. The USGS has another copy of the film to complement the Landsat archive. The declassified collection involves more than 990,000 photographs taken from 1959 through 1980 and was released on two separate occasions: February 1995 (Declass 1) and September 2002 (Declass 2). The USGS copy is maintained by the Earth Resources Observation and Science (EROS) Center, near Sioux Falls, South Dakota. Both the NARA and EROS provide public access to this unique collection that extends the record of land-surface change back another decade from the advent of the Landsat program that began satellite operations in 1972.

  3. Satellites in Canadian broadcasting

    Science.gov (United States)

    Siocos, C. A.

    The involvement of Canadian broadcasting and related enterprises in satellite telecommunications is surveyed. This includes point-to-point transmissions and direct ones to the general public. The mode of such utilizations is indicated in both these cases. For the forthcoming DBS systems the many types of service offerings and utilization concepts under discussion elasewhere are presented as well as the business prospects and regulatory climate offering them.

  4. Neptune: Minor Satellites

    Science.gov (United States)

    Murdin, P.

    2003-04-01

    All but one of Neptune's minor satellites orbit within or just outside its ringsystem; the exception is the distant object Nereid. Some of them are betterdescribed as `mid-sized' rather than `minor', but are included under thisheading as little is known of them. The inner four, with approximatediameters, are Naiad (60 km), Thalassa (80 km), Despina (150 km) and Galatea(160 km). The first three lie...

  5. Satellite Surveillance: Domestic Issues

    Science.gov (United States)

    2010-02-01

    earthquake and tsunami in the Indian Ocean and Hurricane Katrina in 2005, when the NGA provided graphics for “relief efforts that depicted the locations of...that show the damage resulting from an earthquake , fire, flood, hurricane, oil spill, or volcanic eruption.8 Bush Administration Policies...Satellite information has continued to have important civil applications in such disparate areas as the movement of glaciers in Yakutat Bay in Alaska

  6. Hungarian repeat station survey, 2010

    Directory of Open Access Journals (Sweden)

    Péter Kovács

    2013-03-01

    Full Text Available The last Hungarian repeat station survey was completed between October 2010 and February 2011. Declination, inclination and the total field were observed using one-axial DMI fluxgate magnetometer mounted on Zeiss20A theodolite and GSM 19 Overhauser magnetometer. The magnetic elements of the sites were reduced to the epoch of 2010.5 on the basis of the continuous recordings of Tihany Geophysical Observatory. In stations located far from the reference observatory, the observations were carried out in the morning and afternoon in order to decrease the effect of the distant temporal correction. To further increase the accuracy, on-site dIdD variometer has also been installed near the Aggtelek station, in the Baradla cave, during the survey of the easternmost sites. The paper presents the technical details and the results of our last campaign. The improvement of the accuracy of the temporal reduction by the use of the local variometer is also reported.

  7. Global satellite triangulation and trilateration results

    Science.gov (United States)

    Mueller, I. I.

    1974-01-01

    Summary of the results of the Ohio State University geometric adjustment for the coordinates at 158 satellite tracking stations. In the solution the origin of the coordinate system is defined through the 'inner' adjustment procedure, whereas the orientation is through the Conventional International Origin and the Greenwich Mean Astronomical Meridian, both as defined by the Bureau International de l'Heure. The scale is implemented through Secor observations and weighted height constraints. Chord distances derived from C-band radar observations and from electronic distance measurements are also included, but they seem to have very little effect. The scale selected corresponds to a best fitting ellipsoid of a = 6,378,142 m and 1/f = 298.25. The average standard deviation of a single coordinate is 3.9 m.

  8. 47 CFR 73.1820 - Station log.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Station log. 73.1820 Section 73.1820... Rules Applicable to All Broadcast Stations § 73.1820 Station log. (a) Entries must be made in the station log either manually by a person designated by the licensee who is in actual charge of...

  9. 47 CFR 78.69 - Station records.

    Science.gov (United States)

    2010-10-01

    ... notice was given. (v) Date and time notice was given to the Flight Service Station (Federal Aviation... SERVICE General Operating Requirements § 78.69 Station records. Each licensee of a CARS station shall... time of the beginning and end of each period of transmission of each channel; (b) For all stations,...

  10. Communications satellites - The experimental years

    Science.gov (United States)

    Edelson, B. I.

    1983-10-01

    Only eight years after the launc of Sputnik-1 by the Soviet Union, the first commercial satellite, 'Early Bird', entered service. In just twelve years commercial satellite service extended around the earth and became profitable. The reasons for the successful development of the communications satellite services in a comparatively short time are considered. These reasons are related to the presence of three ingredients, taking into account technology to create the system, communications requirements to form a market, and a management structure to implement the system. The formation of the concept of using earth orbiting satellites for telecommunications is discussed. It is pointed out that the years from 1958 to 1964 were the true 'experimental years' for satellite communications. The rapid development of technology during this crucial period is described, giving attention to passive satellites, active systems, and development satellites.

  11. Low-latitude Pi2 oscillations observed by polar Low Earth Orbiting satellite

    Science.gov (United States)

    Thomas, Neethal; Vichare, Geeta; Sinha, A. K.; Rawat, Rahul

    2015-09-01

    Low-latitude Pi2 pulsations in the topside ionosphere are investigated using vector magnetic field measurements from LEO satellite, CHAMP, and underneath ground station. Substorm-associated Pi2s are initially identified using high-resolution data from Indian station Shillong, during 2007-2009, and are further classified into three subgroups of Pi2 band (6-25 mHz), based on its frequency. During nighttime, coherent in-phase oscillations are observed in the compressional component at satellite and horizontal component at underneath ground station for all the Pi2 events, irrespective of the Pi2 frequency. We observe that the identification of daytime Pi2s at CHAMP (compressional component) depends on the frequency of Pi2 oscillation; i.e., 40%, 45%, and 100% of Pi2 events observed in dayside ground station with frequency between 6-10 mHz, 10-15 mHz, and 15-25 mHz were identified at satellite, respectively. At CHAMP during daytime, the presence of a dominant power in the lower frequencies of Pi2 band, which is unique to satellite, is consistently observed and can modify the Pi2 oscillations. Pi2s having frequency >15 mHz are less affected by these background frequencies, and a clear signature of daytime Pi2s at CHAMP is possible to observe, provided that contribution from non-Pi2 frequencies at satellite from the lower end of Pi2 band is eliminated. Daytime Pi2s identified in the topside ionosphere showed coherent but mostly opposite phase oscillations with underneath ground station, and satellite-to-ground amplitude ratio is, in general, found to be less than 1. Present results indicate that a combination of fast cavity-mode oscillations and an instantaneous transmission of Pi2 electric field from high- to low-latitude ionosphere is responsible for the observation of daytime Pi2s.

  12. Tethered satellite design

    Science.gov (United States)

    Manarini, G.

    1986-01-01

    The capability of the satellite to perform a variety of space operations to be accomplished from the shuttle is reviewed considering use of the satellite with man-in-loop and closed loop modes and deployment (toward or away from Earth, up to 100 km), stationkeeping, retrieval and control of the satellite. Scientific payloads are to be used to perform experiments and scientific investigation for applications such as magnetometry, electrodynamics, atmospheric science, chemical release, communications, plasmaphysics, dynamic environment, and power and thrust generation. The TSS-S will be reused for at least 3 missions after reconfiguration and refurbishment by changing the peculiar mission items such as thermal control, fixed boom for experiments, aerodynamic tail for yaw attitude control, external skin, experiments, and any other feature. The TSS-S is to be composed of three modules in order to allow independent integration of a single module and to facilitate the refurbishment and reconfiguration between flights. The three modules are service, auxiliary propulsion, and payload modules.

  13. A satellite anemometer

    Science.gov (United States)

    Hanson, W. B.; Heelis, R. A.

    1995-01-01

    This report describes the design, development, and testing of components of a satellite anemometer, an instrument for measuring neutral winds in the upper atmosphere from a satellite platform. The device, which uses four nearly identical pressure sensors, measures the angle of arrival of the bulk neutral flow in the satellite frame of reference. It could also be used in a feedback loop to control spacecraft attitude with respect to the ram velocity direction. We have now developed miniaturized ionization pressure gauges that will work well from the slip flow region near 115 km up to the base of the exosphere, which covers the entire altitude range currently being considered for Tether. Laboratory tests have demonstrated a very linear response to changes in ram angle out to +/- 20 deg. (transverse wind component of 2.7 km s(exp -1)) from the ram, and a monotonic response to out beyond 45 deg. Pitch (vertical wind) and yaw (horizontal wind) can be sampled simultaneously and meaningfully up to 10 Hz. Angular sensitivity of 30 arc seconds (approximately 1 ms(exp -1) is readily attainable, but absolute accuracy for winds will be approximately 1 deg (130 m/s) unless independent attitude knowledge is available. The critical elements of the design have all been tested in the laboratory.

  14. Binary Satellite Galaxies

    CERN Document Server

    Evslin, Jarah

    2013-01-01

    Suggestions have appeared in the literature that the following five pairs of Milky Way and Andromeda satellite galaxies are gravitationally bound: Draco and Ursa Minor, Leo IV and V, Andromeda I and III, NGC 147 and 185, and the Magellanic clouds. Under the assumption that a given pair is gravitationally bound, the Virial theorem provides an estimate of its total mass and so its instantaneous tidal radius. For all of these pairs except for the Magellanic clouds the resulting total mass is 2 to 4 orders of magnitude higher than that within the half light radius. Furthermore in the case of each pair except for Leo IV and Leo V, the estimated tidal radius is inferior to the separation between the two satellites. Therefore all or almost all of these systems are not gravitationally bound. We note several possible explanations for the proximities and similar radial velocities of the satellites in each pair, for example they may have condensed from the same infalling structure or they may be bound by a nongravitatio...

  15. Satellite augmentation of cellular type mobile radio telephone systems

    Science.gov (United States)

    Anderson, Roy E.

    NASA's ATS-6 satellite relayed voice bandwidth communications between five trucks and the trucking company dispatchers as the trucks traveled throughout the north-eastern quarter of the contiguous United States. The experiment, conducted over a seven month period, demonstrated that propagation characteristics are much different for the satellite-mobile links than for terrestrial-mobile links. A properly designed satellite system can provide high quality, reliable voice and data communications except where the vehicle-satellite path is shadowed by a structure or terrain feature. Mobile equipment in the experiment was adapted from commercial mobile radios. The vehicle antennas were 75 cm tall, 2 cm diam. Another experiment proved the feasibility of vehicle position surveillance using active two-way tone-code ranging through ATS-6 to provide one line of position and passive one-way ranging by measuring the time-of-arrival of a signal from an independent satellite. A position fix was printed out at an earth station 1 sec after it sent the interrogation signal to the distant vehicle, a towboat on the Mississippi River. The line of position from ATS-6 was accurate to 0.1 nautical mile using a voice bandwidth ranging signal. The line of position from the NOAA GOES satellite was accurate to 2 miles, using 100 Hz signal bandwidth. If the signal from the independent satellite had the same bandwidth and signal-to-noise ratio as ATS-6, the fixes would have been accurate to about 0.1 nautical mile. A concept study concluded that satellites might be a cost effective augmentation of terrestrial cellular type mobile radio telephone systems. The satellites would serve thinly populated areas where terrestrial systems are not cost effective. In the United States, the satellites would serve about 90% of the land area where 20% of the population resides. A multibeam satellite with many channels in each beam would be compatible with the urban terrestrial systems and together they would

  16. An analysis of the wide area differential method of geostationary orbit satellites

    Institute of Scientific and Technical Information of China (English)

    CAI ChengLin; LI XiaoHui; WU HaiTao

    2009-01-01

    This work aims to obtain a wide area differential method for geostationary orbit (GEO) constellation. A comparison between the dilution of precision (DOP) of four-dimensional (4D) calculation including satellite clock errors and ephemeris errors and that of three-dimensional (3D) calculation only including ephemeris errors with the inverse positioning theory of GPS shows the conclusion that all the 3D PDOPs are greatly reduced. Based on this, a basic idea of correcting satellite clock errors and ephem-eris errors apart is put forward, and moreover, a specific method of separation is proposed. Satellite clock errors are separated in a master station with time synchronization, and all the remaining pseudo-range errors after the satellite clock errors have been deducted are used to work out ephemeris corrections of all GEO satellites. By a comparative analysis of user positioning accuracy before and after differential, the wide area differential method is verified to be quite valid for GEO constellation.

  17. Single-Station Sigma for the Iranian Strong Motion Stations

    Science.gov (United States)

    Zafarani, H.; Soghrat, M. R.

    2017-07-01

    In development of ground motion prediction equations (GMPEs), the residuals are assumed to have a log-normal distribution with a zero mean and a standard deviation, designated as sigma. Sigma has significant effect on evaluation of seismic hazard for designing important infrastructures such as nuclear power plants and dams. Both aleatory and epistemic uncertainties are involved in the sigma parameter. However, ground-motion observations over long time periods are not available at specific sites and the GMPEs have been derived using observed data from multiple sites for a small number of well-recorded earthquakes. Therefore, sigma is dominantly related to the statistics of the spatial variability of ground motion instead of temporal variability at a single point (ergodic assumption). The main purpose of this study is to reduce the variability of the residuals so as to handle it as epistemic uncertainty. In this regard, it is tried to partially apply the non-ergodic assumption by removing repeatable site effects from total variability of six GMPEs driven from the local, Europe-Middle East and worldwide data. For this purpose, we used 1837 acceleration time histories from 374 shallow earthquakes with moment magnitudes ranging from M w 4.0 to 7.3 recorded at 370 stations with at least two recordings per station. According to estimated single-station sigma for the Iranian strong motion stations, the ratio of event-corrected single-station standard deviation (Φ ss) to within-event standard deviation (Φ) is about 0.75. In other words, removing the ergodic assumption on site response resulted in 25% reduction of the within-event standard deviation that reduced the total standard deviation by about 15%.

  18. Development of the European Small Geostationary Satellite SGEO

    Science.gov (United States)

    Lübberstedt, H.; Schneider, A.; Schuff, H.; Miesner, Th.; Winkler, A.

    2008-08-01

    The SGEO product portfolio, ranging from Satellite platform delivery up to in-orbit delivery of a turnkey system including satellite and ground control station, is designed for applications ranging from TV Broadcast to multimedia applications, Internet access, mobile or fixed services in a wide range of frequency bands. Furthermore, Data Relay missions such as the European Data Relay Satellite (EDRS) as well as other institutional missions are targeted. Key design features of the SGEO platform are high flexibility and modularity in order to accommodate a very wide range of future missions, a short development time below two years and the objective to build the system based on ITAR free subsystems and components. The system will provide a long lifetime of up to 15 years in orbit operations with high reliability. SGEO is the first European satellite to perform all orbit control tasks solely by electrical propulsion (EP). This design provides high mass efficiency and the capability for direct injection into geostationary orbit without chemical propulsion (CP). Optionally, an Apogee Engine Module based on CP will provide the perigee raising manoeuvres in case of a launch into geostationary transfer orbit (GTO). This approach allows an ideal choice out of a wide range of launcher candidates in dependence of the required payload capacity. SGEO will offer to the market a versatile and high performance satellite system with low investment risk for the customer and a short development time. This paper provides an overview of the SGEO system key features and the current status of the SGEO programme.

  19. Satellite switching concepts for European business services in the nineties

    Science.gov (United States)

    Lombard, D.; Rouffet, D.

    A first generation of business communication satellites are now operational or to be launched. Increased demands for communication satellite facilities will develop, if special services, such as videoconferencing, can be provided at a reasonable cost. For such developments, it will be necessary to define a second generation of business communication satellites. The present investigation evaluates briefly the size of the expected European market for 1995. A study is conducted of the payload structure for the required satellite system, and aspects related to link budgets and power consumption are explored. It is found that system dimensioning is determined by the up-link and by technology. Critical factors are related to the output and input multiplexors for the link budget, the switching matrix, and implications for the mass budget. The best trade-off between technological, mass, and link budget limitations is achieved in connection with the employment of a hinged antennas satellite, using an intermediate number of spot beams and associated earth stations of reasonable size.

  20. On Chinese National Continuous Operating Reference Station System of GNSS

    Directory of Open Access Journals (Sweden)

    CHEN Junyong

    2007-11-01

    Full Text Available Objective: Global navigation satellite system (GNSS Continuous Operating Reference Station (CORS System can maintain a accurate, 3D, geocentric and dynamic reference coordinate frame in the corresponding area, can provide positioning and navigation service. It can also serve for the meteorology, geodynamics, earthquake monitoring and Location Based services (LBS etc in the same area. Until now, our country can’t provide a facing National CORS System serving for every profession and trade, and the national sharing platform of CORS System resources has not been established. So this paper discusses some valuable insight how to construct the National CORS System in China. Method: Constructing goal、Service object、CORS distribution、CORS geographic、geology and communication environment and other factors, are major considerations for the Constructing the National CORS System. Moreover, constructing GNSS CORS is more specific, mainly from four aspects, namely site-selection、civil construction、security measures and equipment-selection for consideration. Outcome: The project of the Constructing Global navigation satellite system (GNSS Continuous Operating Reference Station (CORS System in china is put forward, and is discussed from goal、principle、project and other for construction. Some meaning thought how to construct the National CORS System is submitted Conclusion: The Global navigation satellite system (GNSS Continuous Operating Reference Station (CORS System in china is the lack of a unified planning and design in the national level. So far, the national CORS system serving all walks of life has not been provided, and the national sharing platform of CORS System resources has not been established The primary mission of the Global navigation satellite system (GNSS Continuous Operating Reference Station (CORS System in china is as follows: using data set of GNSS and receiving, transport, process, integration, transmit information and

  1. A Method for Estimating BeiDou Inter-frequency Satellite Clock Bias

    Directory of Open Access Journals (Sweden)

    LI Haojun

    2016-02-01

    Full Text Available A new method for estimating the BeiDou inter-frequency satellite clock bias is proposed, considering the shortage of the current methods. The constant and variable parts of the inter-frequency satellite clock bias are considered in the new method. The data from 10 observation stations are processed to validate the new method. The characterizations of the BeiDou inter-frequency satellite clock bias are also analyzed using the computed results. The results of the BeiDou inter-frequency satellite clock bias indicate that it is stable in the short term. The estimated BeiDou inter-frequency satellite clock bias results are molded. The model results show that the 10 parameters of model for each satellite can express the BeiDou inter-frequency satellite clock bias well and the accuracy reaches cm level. When the model parameters of the first day are used to compute the BeiDou inter-frequency satellite clock bias of the second day, the accuracy also reaches cm level. Based on the stability and modeling, a strategy for the BeiDou satellite clock service is presented to provide the reference of our BeiDou.

  2. Mediatized Humanitarianism

    DEFF Research Database (Denmark)

    Vestergaard, Anne

    2014-01-01

    The article investigates the implications of mediatization for the legitimation strategies of humanitarian organizations. Based on a (full population) corpus of ~400 pages of brochure material from 1970 to 2007, the micro-textual processes involved in humanitarian organizations' efforts to legiti......The article investigates the implications of mediatization for the legitimation strategies of humanitarian organizations. Based on a (full population) corpus of ~400 pages of brochure material from 1970 to 2007, the micro-textual processes involved in humanitarian organizations' efforts...... legitimation by accountancy, legitimation by institutionalization, and legitimation by compensation. The analysis relates these changes to a problem of trust associated with mediatization through processes of mediation....

  3. 47 CFR 25.260 - Time sharing between DoD meteorological satellite systems and non-voice, non-geostationary...

    Science.gov (United States)

    2010-10-01

    ... NVNG licensee shall use an earth station elevation angle of five degrees towards the DoD satellite and... of zero degrees towards the NVNG licensee's satellite, overlapping the DoD protection area. A NVNG... and its directors, officers, employees, affiliates, agents and subcontractors may incur or suffer in...

  4. BeiDou satellite's differential code biases estimation based on uncombined precise point positioning with triple-frequency observable

    Science.gov (United States)

    Fan, Lei; Li, Min; Wang, Cheng; Shi, Chuang

    2017-02-01

    The differential code bias (DCB) of BeiDou satellite is an important topic to make better use of BeiDou system (BDS) for many practical applications. This paper proposes a new method to estimate the BDS satellite DCBs based on triple-frequency uncombined precise point positioning (UPPP). A general model of both triple-frequency UPPP and Geometry-Free linear combination of Phase-Smoothed Range (GFPSR) is presented, in which, the ionospheric observable and the combination of triple-frequency satellite and receiver DCBs (TF-SRDCBs) are derived. Then the satellite and receiver DCBs (SRDCBs) are estimated together with the ionospheric delay that is modeled at each individual station in a weighted least-squares estimator, and the satellite DCBs are determined by introducing the zero-mean condition of all available BDS satellites. To validate the new method, 90 day's real tracking GNSS data (from January to March in 2014) collected from 9 Multi-GNSS Experiment (MGEX) stations (equipped with Trimble NETR9 receiver) is used, and the BDS satellite DCB products from German Aerospace Center (DLR) are taken as reference values for comparison. Results show that the proposed method is able to precisely estimate BDS satellite DCBs: (1) the mean value of the day-to-day scattering for all available BDS satellites is about 0.24 ns, which is reduced in average by 23% when compared with the results derived by only GFPSR. Moreover, the mean value of the day-to-day scattering of IGSO satellites is lower than that of GEO and MEO satellites; (2) the mean value of RMS of the difference with respect to DLR DCB products is about 0.39 ns, which is improved by an average of 11% when compared with the results derived by only GFPSR. Besides, the RMS of IGSO and MEO satellites is at the same level which is better than that of GEO satellites.

  5. The Advanced Communication Technology Satellite and ISDN

    Science.gov (United States)

    Lowry, Peter A.

    1996-01-01

    This paper depicts the Advanced Communication Technology Satellite (ACTS) system as a global central office switch. The ground portion of the system is the collection of earth stations or T1-VSAT's (T1 very small aperture terminals). The control software for the T1-VSAT's resides in a single CPU. The software consists of two modules, the modem manager and the call manager. The modem manager (MM) controls the RF modem portion of the T1-VSAT. It processes the orderwires from the satellite or from signaling generated by the call manager (CM). The CM controls the Recom Laboratories MSPs by receiving signaling messages from the stacked MSP shelves ro units and sending appropriate setup commands to them. There are two methods used to setup and process calls in the CM; first by dialing up a circuit using a standard telephone handset or, secondly by using an external processor connected to the CPU's second COM port, by sending and receiving signaling orderwires. It is the use of the external processor which permits the ISDN (Integrated Services Digital Network) Signaling Processor to implement ISDN calls. In August 1993, the initial testing of the ISDN Signaling Processor was carried out at ACTS System Test at Lockheed Marietta, Princeton, NJ using the spacecraft in its test configuration on the ground.

  6. The Medicina Station Status Report

    Science.gov (United States)

    Orfei, Alessandro; Orlati, Andrea; Maccaferri, Giuseppe

    2013-01-01

    General information about the Medicina Radio Astronomy Station, the 32-m antenna status, and the staff in charge of the VLBI observations is provided. In 2012, the data from geodetic VLBI observations were acquired using the Mark 5A recording system with good results. Updates of the hardware were performed and are briefly described.

  7. 77 FR 16175 - Station Blackout

    Science.gov (United States)

    2012-03-20

    ... turbine trip and unavailability of the onsite emergency ac power system). Station blackout does not... plant achieves safe shutdown by relying on components that are not ac powered, such as turbine- or..., or seismic activity and that preexisting licensing requirements specified sufficient...

  8. Remote input/output station

    CERN Multimedia

    1972-01-01

    A general view of the remote input/output station installed in building 112 (ISR) and used for submitting jobs to the CDC 6500 and 6600. The card reader on the left and the line printer on the right are operated by programmers on a self-service basis.

  9. Mobile Alternative Fueling Station Locator

    Energy Technology Data Exchange (ETDEWEB)

    2009-04-01

    The Department of Energy's Alternative Fueling Station Locator is available on-the-go via cell phones, BlackBerrys, or other personal handheld devices. The mobile locator allows users to find the five closest biodiesel, electricity, E85, hydrogen, natural gas, and propane fueling sites using Google technology.

  10. Mobile Lunar Laser Ranging Station

    Science.gov (United States)

    Intellect, 1977

    1977-01-01

    Harlan Smith, chairman of the University of Texas's Astronomy Department, discusses a mobile lunar laser ranging station which could help determine the exact rates of movement between continents and help geophysicists understand earthquakes. He also discusses its application for studying fundamental concepts of cosmology and physics. (Editor/RK)

  11. Barrow Meteoroloigcal Station (BMET) Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Ritsche, MT

    2004-11-01

    The Barrow meteorology station (BMET) uses mainly conventional in situ sensors mounted at four different heights on a 40 m tower to obtain profiles of wind speed, wind direction, air temperature, and humidity. It also obtains barometric pressure, visibility, and precipitation data.

  12. OMV Deployed From Space Station

    Science.gov (United States)

    1986-01-01

    In this 1986 artist's concept, the Orbital Maneuvering Vehicle (OMV), at right, prepares to reboost the Hubble Space Telescope after being deployed from an early Space Station configuration (left). As envisioned by Marshall Space Flight Center plarners, the OMV would be a remotely-controlled free-flying space tug which would place, rendezvous, dock, and retrieve orbital payloads.

  13. "Artificial intelligence" at streamgaging stations

    Science.gov (United States)

    R. B. Thomas

    1985-01-01

    Two types of problems are related to collecting hydrologic data at stream gaging stations. One includes the technical/logistical questions associated with measuring and transferring data for processing. Effort spent on these problems ranges from improving devices for sensing data to using electronic data loggers.

  14. The Gravity Fields of the Saturnian Satellites

    Science.gov (United States)

    Iess, L.

    2011-12-01

    In its tour of the Saturnian system, begun on July 1st, 2004, the Cassini spacecraft had many close flybys of Saturn's main satellites. However, due to impossibility to carry out simultaneously remote sensing observations and microwave tracking from ground, only a small fraction of those flybys could be exploited for gravity measurements. So far, the quadrupole field has been mapped only for Titan, Rhea and Enceladus, while for Hyperion and Iapetus the mass was the only accessible parameter. For Titan and Enceladus, the only satellites targeted more than once for gravity observations, also a rough geoid to degree and order 3 has been determined. Satellite gravity investigations rely upon accurate measurements of the spacecraft range rate, enabled by coherent, two-way radio links at X and Ka band (8.4 and 32.5 GHz). The use of hydrogen masers frequency standards at the ground station and the consid-erable suppression of plasma noise at X and Ka band frequen-cies provide range rate accuracies of 10-30 micron/s at integra-tion times of 60 s. Thanks to the higher frequency of the radio link, these measurement accuracies are in the average a factor of 10 better than those attained by Galileo in its tour of the Jovian system. However, in order to attain a reliable determination of the low degree field, good measurements must be combined with appropriate flyby geometries and adequate sampling, a condition that necessarily requires multiple flybys. We review the main results obtained so far by Cassini for Titan, Rhea and Enceladus, and discuss the methods of analysis used by the Radio Science Team.

  15. A novel emergency system for low earth orbit satellites using Galileo GNSS

    NARCIS (Netherlands)

    Gill, E.K.A.; Helderweirt, A.

    2010-01-01

    Low Earth Orbit (LEO) satellites have a limited direct contact time with the stations of their ground segment. This fundamentally constraints a timeliness reaction of the mission control center in case of emergency situations onboard the LEO spacecraft. To enable such a rapid reaction to emergency s

  16. Low-tech Highly Efficient Radiotechnical Solutions for Meteors and Satellite Observations

    Directory of Open Access Journals (Sweden)

    Vovk, V.S.

    2017-01-01

    Full Text Available Single-station technique of meteors’ observation using inexpensive receivers is developed. The receivers are also suitable for observing active artificial Earth’s satellites on solar-synchronous orbits when measuring the Doppler shift frequency at which they emit.

  17. Mapping Offshore Winds Around Iceland Using Satellite Synthetic Aperture Radar and Mesoscale Model Simulations

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Badger, Merete; Nawri, Nikolai

    2015-01-01

    The offshore wind climate in Iceland is examined based on satellite synthetic aperture radar (SAR), coastal meteorological station measurements, and results from two atmospheric model data sets, HARMONIE and NORA10. The offshore winds in Iceland are highly influenced by the rugged coastline. Lee...

  18. TOLNet - A Tropospheric Ozone Lidar Profiling Network for Satellite Continuity and Process Studies

    Science.gov (United States)

    Newchurch, Michael J.; Kuang, Shi; Wang, Lihua; LeBlanc, Thierry; Alvarez II, Raul J.; Langford, Andrew O.; Senff, Christoph J.; Brown, Steve; Johnson, Bryan; Burris, John F.; hide

    2015-01-01

    NASA initiated an interagency ozone lidar observation network under the name TOLNet to promote cooperative multiple-station ozone-lidar observations to provide highly time-resolved (few minutes) tropospheric-ozone vertical profiles useful for air-quality studies, model evaluation, and satellite validation.

  19. Analysis of BeiDou Satellite Measurements with Code Multipath and Geometry-Free Ionosphere-Free Combinations.

    Science.gov (United States)

    Zhao, Qile; Wang, Guangxing; Liu, Zhizhao; Hu, Zhigang; Dai, Zhiqiang; Liu, Jingnan

    2016-01-20

    Using GNSS observable from some stations in the Asia-Pacific area, the carrier-to-noise ratio (CNR) and multipath combinations of BeiDou Navigation Satellite System (BDS), as well as their variations with time and/or elevation were investigated and compared with those of GPS and Galileo. Provided the same elevation, the CNR of B1 observables is the lowest among the three BDS frequencies, while B3 is the highest. The code multipath combinations of BDS inclined geosynchronous orbit (IGSO) and medium Earth orbit (MEO) satellites are remarkably correlated with elevation, and the systematic "V" shape trends could be eliminated through between-station-differencing or modeling correction. Daily periodicity was found in the geometry-free ionosphere-free (GFIF) combinations of both BDS geostationary Earth orbit (GEO) and IGSO satellites. The variation range of carrier phase GFIF combinations of GEO satellites is -2.0 to 2.0 cm. The periodicity of carrier phase GFIF combination could be significantly mitigated through between-station differencing. Carrier phase GFIF combinations of BDS GEO and IGSO satellites might also contain delays related to satellites. Cross-correlation suggests that the GFIF combinations' time series of some GEO satellites might vary according to their relative geometries with the sun.

  20. Analysis of BeiDou Satellite Measurements with Code Multipath and Geometry-Free Ionosphere-Free Combinations

    Directory of Open Access Journals (Sweden)

    Qile Zhao

    2016-01-01

    Full Text Available Using GNSS observable from some stations in the Asia-Pacific area, the carrier-to-noise ratio (CNR and multipath combinations of BeiDou Navigation Satellite System (BDS, as well as their variations with time and/or elevation were investigated and compared with those of GPS and Galileo. Provided the same elevation, the CNR of B1 observables is the lowest among the three BDS frequencies, while B3 is the highest. The code multipath combinations of BDS inclined geosynchronous orbit (IGSO and medium Earth orbit (MEO satellites are remarkably correlated with elevation, and the systematic “V” shape trends could be eliminated through between-station-differencing or modeling correction. Daily periodicity was found in the geometry-free ionosphere-free (GFIF combinations of both BDS geostationary Earth orbit (GEO and IGSO satellites. The variation range of carrier phase GFIF combinations of GEO satellites is −2.0 to 2.0 cm. The periodicity of carrier phase GFIF combination could be significantly mitigated through between-station differencing. Carrier phase GFIF combinations of BDS GEO and IGSO satellites might also contain delays related to satellites. Cross-correlation suggests that the GFIF combinations’ time series of some GEO satellites might vary according to their relative geometries with the sun.