Sample records for alouette satellites

  1. Characteristics of ionospheric bubbles determined from aspect sensitive scatter spread F observed with Alouette 1

    Aspect sensitive scatter from bubbles is observed on a large percentage of equatorial Alouette 1 ionograms. The occurrence frequency of bubbles increases sharply (from zero) after sunset and reaches a maximum at about 23--24 hours local time. Near midnight, bubbles are observed in the topside ionosphere on about 65% of American and African satellite passes and on about 50% of Asian passes. The frequency of occurrence decreases gradually throughout the postmidnight and morning periods and becomes almost zero near noon. Averaged over the whole day, the occurrence of bubbles at Asian logitudes is about one half that at American and African longitudes. The occurrence of bubbles peaks at the December solstice for American longitudes and at the June solstice for Asian longitudes. The above observations imply that bubbles are initiated by field-aligned currents at the steep density gradient at the bottom of the postsunset F layer by the mechanism proposed by K. D. Cole. After initiation the Rayleigh-Taylor instability takes over to raise the bubbles through the F layer. Alouette 1 observations indicate that the bubbles rise to a maximum height of about 600--1000 km near midnight. The height then decreases gradually until some time after sunrise. Ray tracing, assuming aspect sensitive scatter and a circular cross section for the field-aligned bubble, indicates that a particular, typical bubble was about 28 km in radius and intersected the vertical plane through the satellite in the magnetic east-west direction, about 550 km below and about 750 km to the east or west of the satellite. In the topside ionosphere below Alouette 1, bubbles never seem to occupy more than about 2% of the total space

  2. Density profiles from the Alouette 1, 2 and ISIS 1, 2 topside sounder instrument on CD-ROM and WWW

    A data base was assembled that includes all the topside electron density profiles from the Alouette and ISIS topside sounder missions that were archived at the National Space Science Data Center. The 176,622 profiles constitute a unique data resource for the modeling of the topside ionosphere covering more than one solar cycle from 1962 to 1979. This data set is more than 4 times the amount of data originally used by Bent and his colleagues for building the BENT topside model (Bent et al., 1972) that is still widely used for specifications of topside electron densities. The topside model in the International Reference Ionosphere (IRI) is based on an analytical evaluation of the Bent model and its underlying database. The original binary data sets were decoded at NSSDC and converted to a common ASCII data format (see APPENDIX). The data are available online on NSSDCs anonymous ftp site ( or can be provided on 1 CD-ROM. It is worth noting that there is an effort underway at NASA's Goddard Space Flight Center (R. Benson, PI) to digitize a large number of the original analog telemetry tapes. As of January 2000 more than 300,000 ionograms have been made available online in digital form (data access and project description at http://nssdc/space/isis/isis-status.html). A follow-on project (B. Reinisch, PI) is now working on the automated scaling and inversion of these ionograms into electron density profiles. (author)

  3. Satellite Geomagnetism

    Olsen, Nils; Stolle, Claudia


    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. 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 c...

  4. Centriolar satellites

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


    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....

  5. Satellite Geomagnetism

    Olsen, Nils; Stolle, Claudia


    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...

  6. Satellite Communications

    Pelton, Joseph N


    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

  7. Satellite observations


    In 1982 and 1983, six scientific satellites were operated successfully. Two of them, JIKIKEN and ISS-b, performed observations of the Earth's plasma environment. HINOTORI, the solar maximum satellite, observed a number of solar flares. HAKUCHO and newly launched TENMA conducted various observations of cosmic X-ray sources. HIMAWARI-2 is a meteorological satellite but its payload includes a solar particle monitor. EXOS-C was successfully launched in February, 1983, and participants in the MAP (Middle Atmosphere Program). Following these missions, the PLANET-A project comprising two missions, MS-T5 and PLANET-A, is under preparation for the participation in the international cooperative exploration of Comet P/Halley. The third X-ray astronomy satellite ASTRO-C is currently scheduled for 1987 launch.

  8. Some background about satellites

    Burns, Joseph A.


    Four tables of planetary and satellite data are presented which list satellite discoveries, planetary parameters, satellite orbits, and satellite physical properties respectively. A scheme for classifying the satellites is provided and it is noted that most known moons fall into three general classes: regular satellites, collisional shards, and irregular satellites. Satellite processes are outlined with attention given to origins, dynamical and thermal evolution, surface processes, and composition and cratering. Background material is provided for each family of satellites.

  9. Satellite description

    Gillett, F. C.; Clegg, P. E.; Neugebauer, G.; Langford, D.; Pouw, A.; Irace, W.; Houck, J.

    The onboard computers and their associated software, the attitude control system, and data recording and the communication links of the infrared astronomy satellite (TRAS) are discussed. The IRAS telescope system is considered in detail. Attention is directed towards the cryogenics, thermal control, optics, focal plane assembly, and electronics associated with the telescope system.

  10. Satellite Heart


    The usefulness of China’s own global navigation system is being extended by technological breakthroughs China has successfully developed the country’s first navigation chip that is expected to be the heart of the country’s satellite-based navigation system,according to a report released on February 21. The Navigation I chip,developed by the Shanghai Fukong Hualong Micro-system

  11. Solar satellites

    Poher, C.


    A reference system design, projected costs, and the functional concepts of a satellite solar power system (SSPS) for converting sunlight falling on solar panels of a satellite in GEO to a multi-GW beam which could be received by a rectenna on earth are outlined. Electricity transmission by microwaves has been demonstrated, and a reference design system for supplying 5 GW dc to earth was devised. The system will use either monocrystalline Si or concentrator GaAs solar cells for energy collection in GEO. Development is still needed to improve the lifespan of the cells. Currently, the cell performance degrades 50 percent in efficiency after 7-8 yr in space. Each SSPS satellite would weigh either 34,000 tons (Si) or 51,000 tons (GaAs), thereby requiring the fabrication of a heavy lift launch vehicle or a single-stage-to-orbit transport in order to minimize launch costs. Costs for the solar panels have been estimated at $500/kW using the GaAs technology, with transport costs for materials to GEO being $40/kg.

  12. Internetworking with satellite constellations

    Wood, L.


    Here, we examine networking and internetworking issues affecting satellite networking in complex satellite constellation networks, and determine what is needed in order to support services based on the TCP/IP suite well in satellite constellations.

  13. Geostationary Satellite (GOES) Images

    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...

  14. Iodine Satellite

    Kamhawi, Hani; Dankanich, John; Martinez, Andres; Petro, Andrew


    The Iodine Satellite (iSat) spacecraft will be the first CubeSat to demonstrate high change in velocity from a primary propulsion system by using Hall thruster technology and iodine as a propellant. The mission will demonstrate CubeSat maneuverability, including plane change, altitude change and change in its closest approach to Earth to ensure atmospheric reentry in less than 90 days. The mission is planned for launch in fall 2017. Hall thruster technology is a type of electric propulsion. Electric propulsion uses electricity, typically from solar panels, to accelerate the propellant. Electric propulsion can accelerate propellant to 10 times higher velocities than traditional chemical propulsion systems, which significantly increases fuel efficiency. To enable the success of the propulsion subsystem, iSat will also demonstrate power management and thermal control capabilities well beyond the current state-of-the-art for spacecraft of its size. This technology is a viable primary propulsion system that can be used on small satellites ranging from about 22 pounds (10 kilograms) to more than 1,000 pounds (450 kilograms). iSat's fuel efficiency is ten times greater and its propulsion per volume is 100 times greater than current cold-gas systems and three times better than the same system operating on xenon. iSat's iodine propulsion system consists of a 200 watt (W) Hall thruster, a cathode, a tank to store solid iodine, a power processing unit (PPU) and the feed system to supply the iodine. This propulsion system is based on a 200 W Hall thruster developed by Busek Co. Inc., which was previously flown using xenon as the propellant. Several improvements have been made to the original system to include a compact PPU, targeting greater than 80 percent reduction in mass and volume of conventional PPU designs. The cathode technology is planned to enable heaterless cathode conditioning, significantly increasing total system efficiency. The feed system has been designed to

  15. Asteroid Satellites

    Merline, W. J.


    Discovery and study of small satellites of asteroids or double asteroids can yield valuable information about the intrinsic properties of asteroids themselves and about their history and evolution. Determination of the orbits of these moons can provide precise masses of the primaries, and hence reliable estimates of the fundamental property of bulk density. This reveals much about the composition and structure of the primary and will allow us to make comparisons between, for example, asteroid taxonomic type and our inventory of meteorites. The nature and prevalence of these systems will also give clues as to the collisional environment in which they formed, and have further implications for the role of collisions in shaping our solar system. A decade ago, binary asteroids were more of a theoretical curiosity. In 1993, the Galileo spacecraft allowed the first undeniable detection of an asteroid moon, with the discovery of Dactyl, a small moon of Ida. Since that time, and particularly in the last year, the number of known binaries has risen dramatically. Previously odd-shaped and lobate near-Earth asteroids, observed by radar, have given way to signatures indicating, almost certainly, that at least four NEAs are binary systems. The tell-tale lightcurves of several other NEAs reveal a high likelihood of being double. Indications are that among the NEAs, there may be a binary frequency of several tens of percent. Among the main-belt asteroids, we now know of 6 confirmed binary systems, although their overall frequency is likely to be low, perhaps a few percent. The detections have largely come about because of significant advances in adaptive optics systems on large telescopes, which can now reduce the blurring of the Earth's atmosphere to compete with the spatial resolution of space-based imaging (which itself, via HST, is now contributing valuable observations). Most of these binary systems have similarities, but there are important exceptions. Searches among other

  16. Satellite data compression

    Huang, Bormin


    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-

  17. Trends in communications satellites

    Curtin, Denis J


    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

  18. Xichang Satellite Launch Center



    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.

  19. China's satellite communications discussed

    Ruhou, Z.


    In 1972, China began to enter the age of satellite comunications, and it was realized that satellites could play a large role in television transmission in China. The experimental broadcasting of satellite television programs was begun in 1978, and satisfactory results were obtained. The success of the television transmission demonstration has led to important decisions regarding development of a domestic satellite communications system. Before specialized communications satellites are launched, the decision was made to lease an international communications satellite transmitter. The responsibility of the ground stations were discussed.

  20. Variation of electron and ion density distribution along Earth's magnetic field line deduced from whistler mode (wm) sounding of image/rpi satellite below altitude 5000 km

    Hazra, Susmita

    This thesis provides a detailed survey and analysis of whistler mode (WM) echoes observed by IMAGE/RPI satellite during the years 2000-2005 below the altitude of 5000 km. Approximately 2500 WM echoes have been observed by IMAGE during this period. This includes mostly specularly reflected whistler mode (SRWM) echoes and ~400 magnetospherically reflected whistler mode (MRWM) echoes. Stanford 2D raytracing simulations and the diffusive equilibrium density model have been applied to 82 cases of MRWM echoes, observed during August-December of the year 2005 below 5000 km to determine electron and ion density measurements along Earth's magnetic field line. These are the first results of electron and ion density measurements from WM sounding covering L-shells ~1.6-4, a wide range of geomagnetic conditions (Kp 0+ to 7), and during solar minima (F10.2~70-120) in the altitude range 90 km to 4000 km. The electron and ion density profiles obtained from this analysis were compared with in situ measurements on IMAGE (passive recording; electron density (Ne)), DMSP (~850 km; Ne and ions), CHAMP (~350 km; Ne), Alouette (~500-2000 km; Ne and ions), ISIS-1, 2 (~600-3500 km; Ne, ions), AE (~130-2000 km; ions) satellites, bottom side sounding from nearby ionosonde stations (Ne), and those by GCPM (Global Core Plasma Model), IRI-2012 (International Reference Ionosphere). Based on this analysis it is found that: (1) Ne shows a decreasing trend from L-shell 1.6 to 4 on both the day and night sides of the plasmasphere up to altitude ~1000 km, which is also confirmed by the GCPM and IRI-2012 model. (2) Above ~2000 km altitude, GCPM underestimates Ne by ~30-90% relative to RPI passive measurements, WM sounding results. (3) Below 1500 km, the Ne is higher at day side than night side MLT (Magnetic Local Time). Above this altitude, significant MLT dependence of electron density is not seen. (4) Ion densities from WM sounding measurements are within 10-35% of those from the Alouette, AE, and

  1. Galileo satellite antenna modeling

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


    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.

  2. GPS Satellite Simulation Facility

    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...

  3. China's Recoverable Satellites

    Tang Boehang


    @@ 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.

  4. Satellite broadcasting in Europe

    Bartholome, P.


    Three main communications services are recognized by the International Telecommunications Union: the Fixed Service, the Mobile Service and the Broadcasting Service. In Europe, EUTELSAT has just begun to exploit the first ECS satellite. The ESA-launched satellite was originally designed to provide an international public telecommunication service, however, the satellite will be used now almost exclusively for TV program distribution, while a second ECS satellite will be used for telephony. Despite plans for the launch of a third, countries in Europe are looking to other organizations such as INTELSAT for greater satellite capacity. Other organizations include Unisat, DFS/Copernicus, GDL, and Videosat. Both satellite and cable networks will increase the program-viewing audience, thus encouraging plans for a pan-European television service intended for an international audience. Although the combination of cable networks and distribution satellites looks promising, high-power broadcasting satellites will play an important role because of flexibility and additional program distribution.

  5. Satellite Tags- Hawaii EEZ

    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...

  6. Satellite communication engineering

    Kolawole, Michael Olorunfunmi


    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

  7. Theory of geostationary satellites

    Zee, Chong-Hung


    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...

  8. Meteorological satellite systems

    Tan, Su-Yin


    “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.

  9. Communication satellite applications

    Pelton, Joseph N.

    The status and future of the technologies, numbers and services provided by communications satellites worldwide are explored. The evolution of Intelsat satellites and the associated earth terminals toward high-rate all-digital telephony, data, facsimile, videophone, videoconferencing and DBS capabilities are described. The capabilities, services and usage of the Intersputnik, Eutelsat, Arabsat and Palapa systems are also outlined. Domestic satellite communications by means of the Molniya, ANIK, Olympus, Intelsat and Palapa spacecraft are outlined, noting the fast growth of the market and the growing number of different satellite manufacturers. The technical, economic and service definition issues surrounding DBS systems are discussed, along with presently operating and planned maritime and aeronautical communications and positioning systems. Features of search and rescue and tracking, data, and relay satellite systems are summarized, and services offered or which will be offered by every existing or planned communication satellite worldwide are tabulated.

  10. GPS Satellites Orbits: Resonance

    Luiz Danilo Damasceno Ferreira


    Full Text Available The effects of perturbations due to resonant geopotential harmonics on the semimajor axis of GPS satellites are analyzed. For some GPS satellites, secular perturbations of about 4 m/day can be obtained by numerical integration of the Lagrange planetary equations considering in the disturbing potential the main secular resonant coefficients. Amplitudes for long-period terms due to resonant coefficients are also exhibited for some hypothetical satellites orbiting in the neighborhood of the GPS satellites orbits. The results are important to perform orbital maneuvers of GPS satellites such that they stay in their nominal orbits. Also, for the GPS satellites that are not active, the long-period effects due to the resonance must be taken into account in the surveillance of the orbital evolutions of such debris.

  11. Satellite communication engineering

    Kolawole, Michael Olorunfunmi


    Highlighting satellite and earth station design, links and communication systems, error detection and correction, and regulations and procedures for system modeling, integrations, testing, and evaluation, Satellite Communication Engineering provides a simple and concise overview of the fundamental principles common to information communications. It discusses block and feedback ciphering; covers orbital errors; evaluates multi-beam satellite networks; illustrates bus, electrical, and mechanical systems design; analyzes system reliability and availability; elucidates reflector/lens, phased array

  12. Methods of satellite oceanography

    Stewart, R. H.


    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.

  13. Artificial earth satellites

    V. R. Thiruvenkatachar


    Full Text Available A general discussion is given of the scientific and technological problems involved in the launching of earth satellites, covering various aspects such as the dynamical relationships involved, the propulsion and guidance systems, tracking and data transmission etc. The possible uses of satellites for scientific research as well as some of the likely future developments are also briefly indicated.

  14. Satellite communication systems

    Evans, BG


    The book is very clear and comprehensive. The scope of the book is very large: almost all aspects of current satellite communication systems are studied. Hence, the book keeps its promise in that it provides a quick start for someone who is new to the satellite communications business.

  15. Communications technology satellite


    A description of the Communications Technology Satellite (CTS), its planned orbit, its experiments, and associated ground facilities was given. The communication experiments, to be carried out by a variety of groups in both the United States and Canada, include tele-education, tele-medicine, community interaction, data communications and broadcasting. A historical summary of communications satellite development was also included.

  16. Beginnings of Satellite Navigation

    Miljenko Solarić


    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

  17. Overview of commercial satellite communications

    Beakley, G. W.


    A brief history of communications satellites is presented, taking into account the launching of Sputnik 1 in October 1957, the Explorer 1 in January of 1958, the launch of the Score as the world's first active communications satellite in December 1958, the Communications Satellite Act in 1962, and the launch of 'Early Bird' in 1964. The Intelsat satellites are considered along with maritime satellite communications, the U.S. domestic satellite systems, Alaskan satellite communications, cable television, broadcast TV stations, print media, the hotel/motel industry as a large market for satellite communications terminals, the opening of a minicable and satellite master antenna TV market for TV receive-only systems, and business telecommunications earth terminals. Attention is also given to future directions regarding satellite positions, the concept of 'video-plus', and direct broadcast satellites.

  18. Handbook of satellite applications

    Madry, Scott; Camacho-Lara, Sergio


    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...

  19. Biological satellite Kosmos-936

    Vedeshin, L. A.


    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.

  20. Small Satellite Transporter Project

    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...

  1. Epos TCS Satellite Data

    Manunta, Michele; Mandea, Mioara; Fernández-Turiel, José Luis; Stramondo, Salvatore; Wright, Tim; Walter, Thomas; Bally, Philippe; Casu, Francesco; Zeni, Giovanni; Buonanno, Sabatino; Zinno, Ivana; Tizzani, Pietro; Castaldo, Raffaele; Ostanciaux, Emilie; Diament, Michel; Hooper, Andy; Maccaferri, Francesco; Lanari, Riccardo


    TCS Satellite Data is devoted to provide Earth Observation (EO) services, transversal with respect to the large EPOS community, suitable to be used in several application scenarios. In particular, the main goal is to contribute with mature services that have already well demonstrated their effectiveness and relevance in investigating the physical processes controlling earthquakes, volcanic eruptions and unrest episodes as well as those driving tectonics and Earth surface dynamics. The TCS Satellite Data will provide two kinds of services: satellite products/services, and Value-added satellite products/services. The satellite products/services are composed of three (EPOSAR, GDM and COMET) well-identified and partly already operational elements for delivering Level 1 products. Such services will be devoted to the generation of SAR interferograms, DTM and ground displacement maps through the exploitation of different advanced EO techniques for InSAR and optical data analysis. The Value-added satellite products/services are composed of 4 elements (EPOSAR, 3D-Def, Mod and COMET) of Level 2 and 3 products. Such services integrate satellite and in situ measurements and observations to retrieve information on source mechanism, such as the geometry (spatial location, depth, volume changes) and the physical parameters of the deformation sources, through the exploitation of modelling approaches. The TCS Satellite Data will provide products in two different processing and delivery modes: 1- surveillance mode - routinely product generation; 2- on demand mode - product generation performed on demand by the user. Concerning the surveillance mode, the goal is providing continuous satellite measurements in areas of particular interest from a geophysical perspective (supersites). The objective is the detection of displacement patterns changing along time and their geophysical explanation. This is a valid approach for inter-seismic movements and volcanic unrest, post-seismic and post

  2. ASTRID II satellit projekt

    Jørgensen, John Leif; Primdahl, Fritz


    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....



    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

  4. China's Meteorological Satellite Application System

    Zhang Jiashen


    @@ 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.

  5. Satellite Imaging System

    AA Somaie


    Full Text Available The aim of this paper is to present the essential elements of the electro-optical imaging system EOIS for space applications and how these elements can affect its function. After designing a spacecraft for low orbiting missions during day time, the design of an electro-imaging system becomes an important part in the satellite because the satellite will be able to take images of the regions of interest. An example of an electro-optical satellite imaging system will be presented through this paper where some restrictions have to be considered during the design process. Based on the optics principals and ray tracing techniques the dimensions of lenses and CCD (Charge Coupled Device detector are changed matching the physical satellite requirements. However, many experiments were done in the physics lab to prove that the resizing of the electro optical elements of the imaging system does not affect the imaging mission configuration. The procedures used to measure the field of view and ground resolution will be discussed through this work. Examples of satellite images will be illustrated to show the ground resolution effects.

  6. Small satellites - An overview

    Ward, A. K.

    The present review of small satellites examines spacecraft activities in the U.K. and compiles a checklist of advantages and applications for the class. These advantages are illustrated with references to recent small satellite missions and technologies developed to facilitate such launches and projects. Specific programs examined include AMPTE-UKS, Viking, and the UoSAT program, and information is given regarding the Small Explorer program, the RAE Space Technology Research Vehicle, the AEA Argos Program, and space research programs in both Japan and India. Low-cost launches are shown to be available in the form of the Ariane Structure for Auxiliary Payloads, the Pegasus and Delta vehicles, and with the Shuttle Free-flying Getaway Special. Small-satellite technologies that play key roles in their effective implementation are: structure/thermal advances, attitude control systems, on-board communications, and power and data-handling systems.

  7. Solar Power Satellites

    Flournoy, Don M


    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.

  8. ESA's satellite communications programme

    Bartholome, P.


    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.

  9. Geostationary satellites collocation

    Li, Hengnian


    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.

  10. Satellite oceanography - The instruments

    Stewart, R. H.


    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.

  11. Oceanography from satellites

    Wilson, W. S.


    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.

  12. Satellites orbits and missions

    Capderou, Michel


    Introduction Keplerian motion 1.1 Preamble 1.2 Acceleration 1.3 Central acceleration 1.4 Newtonian acceleration 1.5 Keplerian motion : trajectory and period 1.6 The three anomalies 1.7 Representation of the anomalies 1.8 Integrals of motion 1.9 Historical note on universal attraction 1.10 Annex : Ellipses Satellites on keplerian orbit 2.1 Gravitational field 2.2 The N-body and the two-body problem 2.3 Orbital parameters 2.4 Case of quasi-circular orbits 2.5 Keplerian period Satellites on real o

  13. GPS satellite surveying

    Leick, Alfred; Tatarnikov, Dmitry


    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

  14. Multispectral satellite image understanding

    Unsalan, Cem


    This book presents a comprehensive review of image processing methods, for the analysis of land use in residential areas. Combining a theoretical framework with highly practical applications, this book describes a system for the effective detection of single houses and streets in very high resolution. It features a Foreword by Prof. Dr. Peter Reinartz of the German Aerospace Center. This title provides end-of-chapter summaries and review questions; presents a detailed review on remote sensing satellites; examines the multispectral information that can be obtained from satellite images, with a

  15. MIST Student Satellite

    Gårdebäck, Agnes; Haugdahl, Vincent


    In this report, parts of the systems engineering of a spacecraft are presented. In 2014 the Royal Institute of Technology KTH initiated a new space technology and research platform, the KTH Space Centre. The first student project at KTH Space Centre was the MIST student satellite with the scope of the system design and construction of a real satellite due for launch in 2017. As part of the MIST project this bachelor thesis covers the mission analysis and parts of the system design. The system...

  16. Satellite Control Laboratory

    Wisniewski, Rafal; Bak, Thomas


    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...

  17. Advances in satellite oceanography

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


    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.

  18. Learning Through Satellite Broadcasting

    Krishnamoorthy, P. V.


    SITE is an experimental project which would provide vital inputs in designing and executing a satellite-based instructional television system, particularly in rural areas, to stimulate national development in India with important managerial, economic, technological, and social implications. (Author/BP)

  19. Observations of artificial satellites



    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.

  20. Man-made Satellites



    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).

  1. Experimental Satellite Quantum Communications.

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


    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. PMID:26252672

  2. Perception via satellite

    Robinove, Charles J.


    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.

  3. Defense Meteorological Satellite Program (DMSP)

    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,...

  4. DFH Satellite Co.,Ltd.



    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.

  5. Cooperative and cognitive satellite systems

    Chatzinotas, Symeon; De Gaudenzi, Riccardo


    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

  6. Thematic mapping from satellite imagery

    Denègre, J


    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

  7. Satellite Control Laboratory

    Wisniewski, Rafal; Bak, Thomas


    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......-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...... 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...

  8. Declassified Intelligence Satellite Photographs

    U.S. Geological Survey


    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.

  9. Small Satellites Big Business?

    A. Marchetto, Carl


    Biography-Carl A. Marchetto is Senior Vice President and President, ATK Space Systems for Alliant Tech¬systems (ATK). Prior to joining ATK in January 2008, Carl was Executive Vice President and General Manager Space Sys¬tems group for Orbital Sciences, where he led an organization designing, building, and servicing communication, space research and earth imaging satellites for commercial, gov¬ernment and academic customers. Carl’s previous experience includes a decade at Eastman Kodak that sa...

  10. Satellite servicing economic study


    Previous studies have shown that satellite servicing is cost effective; however, all of these studies were of different formats, dollar year, learning rates, availability, etc. Therefore, it was difficult to correlate any useful trends from these studies. The reviewed study was initiated to correlate the economic data into a common data base, using a common set of assumptions. A selected set of existed funded programs was then analyzed to provide an independent analysis of the servicing options and potential economic benefits.

  11. STARBANDSM - Satellite Internet Service

    ECT Team, Purdue


    The Internet has become one of the most important communication systems in the present. However people across the continental United States have not been able to get broadband Internet service. StarBand service, with no special phone lines or cable modems required is a feasible solution. StarBand is America’s first consumer two-way, always-on, high-speed satellite Internet service.

  12. Laser ICESat-satellite

    Webredactie M&C


    The ICESat satellite, launched in 2003, is equipped with an altimeter that uses a laser beam to determine its distance from the Earth. Forty short laser pulses per second hit an area of Earth's surface that is 70 metres in diameter. These measurement circles are 170 metres apart. Each measurement represents the average vertical shift in the 70m measurement circle. ICESat can detect variations of 1.5 cm a year or more in the elevation of the ice surface.

  13. SAC-A Satellite

    Machado, Marcos; Roggero, Edgardo; Alonso, Roberto; Anigstein, Pablo; Caruso, Daniel; Bratina, Juan; Vega, Julio; Pena, Ricardo Sanchez


    The SAC-A is a Low Cost - Short Schedule - Small Bus dedicated to test equipment and new technologies which may be used in operational or scientific missions with more immunity to failures. The opportunity to fly in a low orbit for a reasonable period of time, allows the characterization of the behavior of this new instrumentation in real world applications and also to compute performance. The 68 kg satellite will have an almost octagonal configuration to be fitted within the Hitchhiker Motor...

  14. Binary Satellite Galaxies

    Evslin, Jarah


    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. Understanding satellite navigation

    Acharya, Rajat


    This book explains the basic principles of satellite navigation technology with the bare minimum of mathematics and without complex equations. It helps you to conceptualize the underlying theory from first principles, building up your knowledge gradually using practical demonstrations and worked examples. A full range of MATLAB simulations is used to visualize concepts and solve problems, allowing you to see what happens to signals and systems with different configurations. Implementation and applications are discussed, along with some special topics such as Kalman Filter and Ionosphere. W

  16. UCI Satellite-II

    Carroll, Keegan; Chen, Geoffrey Hsiao-Wei; Timilsina, Navin; Walter, Scott; Fimbres, Cristhian; Mai, Zaw; Phung, Diane; Kampley, Leann; Lasquete, Kevin W.S.; Patel, Akash; Dunford , Amy; Deason, Ross; Salazar, Eric Salaza; Tarif , Abdullaah R.; Shojaei, Kamran


    The principal idea involves the utilization of existing solar radiation to degrade model pollutants (midodrine and humic acid) in aqueous solution.  The decomposition of said pollutants will be observed through a photochemical effect known as “fluorescence”, whereby substances emit light after absorbing electromagnetic radiation.  The experiment will be carried out on a Class 2U Cube Satellite; hence the designation of “UCISAT-2.”  In addition, UCISAT-2 will utilize an electric propulsion sys...

  17. China Satellite Navigation Conference

    Liu, Jingnan; Fan, Shiwei; Wang, Feixue


    These Proceedings present selected research papers from CSNC2016, held during 18th-20th May in Changsha, China. The theme of CSNC2016 is Smart Sensing, Smart Perception. These papers discuss the technologies and applications of the Global Navigation Satellite System (GNSS), and the latest progress made in the China BeiDou System (BDS) especially. They are divided into 12 topics to match the corresponding sessions in CSNC2016, which broadly covered key topics in GNSS. Readers can learn about the BDS and keep abreast of the latest advances in GNSS techniques and applications.

  18. Satellite Network Hacking & Security Analysis

    Adam Ali.Zare Hudaib


    Full Text Available Satellites play a significant role in communication, early warning systems, global broadcasting, meteorology, navigation, reconnaissance, remote sensing, and surveillance.Satellite services cover practically every sector, from mobile cellular communication to telemedicine, so any interference with them could have a serious effect. Satellites are a strategic asset for any country and are considered as “critical infrastructure,” therefore they are considerable as privileged targets for a possible cyber attack.

  19. Vibration Testing for Small Satellites

    Wilson, Delbert


    Most people involved in the design and construction of small satellites are unfamiliar with vibration testing. Yet most satellites undergo vibration testing to qualify them for flight. Some familiarity with the basic aspects of vibration testing is needed to insure that a vibration test on a satellite is valid. This paper sets forth the basic equipment, practices and concepts of vibration testing. It provides guidelines for specifying a vibration test, designing fixtures, attaching instrument...

  20. Living antennas on communication satellites

    Lumholt, Michael


    Crises change the global pattern of communication. The communications problems occur because the satellites are optimized to cover specific geographic areas, and these areas cannot be altered once the satellites are in Earth orbit. An effective solution to the problem is to equip communication sa...... satellites with "living" antennas that can adjust their radiation coverage areas according to the new demands. The development of living antennas is, therefore, among the focus areas identified and supported by the European Space Agency, ESA....

  1. The power relay satellite

    Glaser, Peter E.

    The availability and use of renewable energy sources compatible with reducing risks to the global environment are key to sustainable development. Large-scale, renewable energy resources at undeveloped or underutilized sites are potentially available on several continents. The Power Relay Satellite (PRS) concept has the potential to access these remote energy resources by coupling primary electricity generation from terrestrial transmission lines. A global PRS network can be envisioned to provide a high degree of flexibility for supplying energy demands worldwide with wireless power transmitted from sites on Earth to geosynchronous orbit and then reflected to receivers interfacing with terrestrial power transmision networks. Past developments in wireless power transmission (WPT) are reviewed and recent successful results are noted. The origins of the PRS concept, and a possible configuration are discussed, principles of WPT at microwave frequencies, functional requirements, and system design contraints are outlined, and space transportation concepts presented. PRS assessments including applicable technologies, economic projections, and societal issues are highlighted. It is concluded that the PRS provides a promising option to access renewable resources at great distances from major markets, and represents an important stage in the future development in the future of solar power satellites.

  2. Solar power satellite

    Davis, H. P.


    The solar power satellite (SPS) concept, under evaluation by NASA since 1974, is discussed. A typical system providing a total of 10,000 MW of electrical power to the ground receiving stations is considered. Energy conversion systems, including the photovoltaic device category using single-crystal silicon cells, are taken into account, as are the 2.45-GHz microwave power-transmission link and the ground receiver (or rectenna). Concepts involving space construction of the satellite's large structures (5 x 25 km) are described, noting that a process similar to the familiar roll-forming of light sheet metal parts has been adapted to the space environment. Transportation vehicles are discussed, including the Space Shuttle planned to reach 60 flights per year by the mid 1980's. Electrical power forecasts and advanced systems cost projections are analyzed, together with a description of costs estimates. The indirect economics of energy research and development, and the present NASA/DOE SPS program are noted.

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

    Hoder, Douglas; Bergamo, Marcos


    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.

  4. Satellite-based internet: A tutorial

    Hu, Y.; Li, VOK


    In a satellite-based Internet system, satellites are used to interconnect heterogeneous network segments and to provide ubiquitous direct Internet access to homes and businesses. This article presents satellite-based Internet architectures and discusses multiple access control, routing, satellite transport, and integrating satellite networks into the global Internet.

  5. Satellite Control Laboratory

    Wisniewski, Rafal; Bak, Thomas


    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...... 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...... can be implemented in the laboratory, e.g. three-axis attitude control, slew manoeuvres, spins stabilization using magnetic actuation and/or reaction wheels. The spacecraft attitude can be determined applying magnetometer measurements....

  6. The solar power satellite

    Combes, P.F.


    The construction, launch, components, and operations of satellite solar power systems (SSPS) for direct beaming of solar energy converted to electricity to earth stations are outlined. The reference designs of either Si or concentrator GaAs solar cell assemblies large enough to project 5 GW of power are described. The beam will be furnished by klystrons or amplitrons for reception by rectennas on earth. Conforming to the law of amplitude and the equiphase law will permit high efficiencies, pointing accuracy, and low power deposition/sq cm, thus avoiding environmental problems, although some telecommunications systems may suffer interference. The construction of the dipole rectenna grid is sketched, noting that one receiver would be an ellipse sized at 10 x 13 km. Various forms of pollution which could result from the construction of an SSPS are examined.

  7. Integrated Satellite-HAP Systems

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


    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 for an...

  8. Multicast Routing in Satellite Network

    郭惠玲; 宋姝; 李磊; 刘志涛; 郭鹏程


    There are some problems in the dual-layer satellite MPLs metworks to be composed of LEO and MEO. In order to solve the problems, this paper presents a plan by means of unicast LSP to implement multicast in the dual-layer satellite MPLs networks. It has advantages of saving space and reducing extra charge.

  9. Accumulation of satellites

    Formation and evolution of circumplanetary satellite swarms are investigated. Characteristic times of various processes are estimated. The characteristic time for the accumulation of the bodies in the swarm was several orders of magnitude shorter than that of the planet, i.e. than the time of the replenishment of the material by the swarm (108 yr). The model of the accumulation of the swarm is constructed taking into account the increase of its mass due to trapping of heliocentrically moving particles and its decrease due to outfall of the inner part of the swarm onto the growing planet. The accumulation of circumplanetary bodies is also considered. The main features of the evolution of the swarm essentially depend on the size distribution of bodies in the swarm and in the zone of the planet and also on the degree of the concentration of the swarm mass toward the planet. If the sum of the exponents of the inverse power laws of these distributions is less than 7, the model of the transparent swarm developed in this paper should be preferred. When this sum is greater than 7, the model of opaque swarm suggested by A. Harris and W.M. Kaula is better. There is predominant trapping of small particles into the swarm due to their more frequent collisions. Optical thickness of the protoplanetary cloud in radial direction is estimated. It is shown that at the final stage of the planetary accumulation, the cloud was semitransparent in the region of terrestrial planets and volatile substances evaporated at collisions could be swept out from the outer parts of the satellite swarm by the solar wind

  10. Sky alert! when satellites fail

    Johnson, Les


    How much do we depend on space satellites? Defense, travel, agriculture, weather forecasting, mobile phones and broadband, commerce...the list seems endless. But what would our live be like if the unimaginable happened and, by accident or design, those space assets disappeared? Sky Alert! explores what our world would be like, looking in turn at areas where the loss could have catastrophic effects. The book - demonstrates our dependence on space technology and satellites; - outlines the effect on our economy, defense, and daily lives if satellites and orbiting spacecraft were destroyed; - illustrates the danger of dead satellites, spent rocket stages, and space debris colliding with a functioning satellites; - demonstrates the threat of dramatically increased radiation levels associated with geomagnetic storms; - introduces space as a potential area of conflict between nations.

  11. Induction studies with satellite data

    Olsen, Nils


    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...... 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 are...

  12. Polar-Orbiting Satellite (POES) Images

    National Oceanic and Atmospheric Administration, Department of Commerce — Visible and Infrared satellite imagery taken from camera systems or radiometer instruments on satellites in orbit around the poles. Satellite campaigns include...

  13. The exterior tidal potential acting on a satellite. [satellite orbits/satellite perturbation - gravitation effects

    Musen, P.


    A theory is presented that points out the existence of several long period and 'cross effects' in the coefficients in the expansion of the geopotential and in the motion of satellites. The tidal potential, defined as small periodic variations in the geopotential, was calculated. The influence of these geopotential variations on satellite perturbation is examined. Spherical harmonics were employed.

  14. Theory of satellite geodesy applications of satellites to geodesy

    Kaula, William M


    The main purpose of this classic text is to demonstrate how Newtonian gravitational theory and Euclidean geometry can be used and developed in the earth's environment. The second is to collect and explain some of the mathematical techniques developed for measuring the earth by satellite.Book chapters include discussions of the earth's gravitational field, with special emphasis on spherical harmonies and the potential of the ellipsoid; matrices and orbital geometry; elliptic motion, linear perturbations, resonance, and other aspects of satellite orbit dynamics; the geometry of satellite obser

  15. Multi-mission Satellite Management

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


    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.

  16. Advanced Communications Technology Satellite (ACTS)

    Gedney, Richard T.; Schertler, Ronald J.


    The NASA Advanced Communications Technology Satellite (ACTS) was conceived to help maintain U.S. leadership in the world's communications-satellite market. This experimental satellite is expected to be launched by NASA in 1992 and to furnish the technology necessary for establishing very small aperture terminal digital networks which provide on-demand full-mesh connectivity, and 1.544-MBPS services with only a single hop. Utilizing on-board switching and processing, each individual voice or data circuit can be separately routed to any location in the network. This paper provides an overview of the ACTS and discusses the value of the technology for future communications systems.

  17. Magnetic Satellite Missions and Data

    Olsen, Nils; Kotsiaros, Stavros


    Although the first satellite observations of the Earth’s magnetic field were already taken more than 50 years ago, continuous geomagnetic measurements from space are only available since 1999. The unprecedented time-space coverage of this recent data set opened revolutionary new possibilities for...... exploring the Earth’s magnetic field from space. In this chapter we discuss characteristics of satellites measuring the geomagnetic field and report on past, present and upcoming magnetic satellite missions. We conclude with some basics about space magnetic gradiometry as a possible path for future...

  18. Satellite communications principles and applications

    Calcutt, David


    Satellites are increasingly used for global communications, as well as for radio and television transmissions. With the growth of mobile communications, and of digital technology, the use of satellite systems is set to expand substantially and already all students of electronics or communications engineering must study the subject.This book steers a middle path between offering a basic understanding of the process of communication by satellite and the methodology used; and the extensive mathematical analysis normally adopted in similar texts. It presents the basic concepts, using as mu

  19. Leucocytes, cytokines and satellite cells

    Paulsen, Gøran; Mikkelsen, Ulla Ramer; Raastad, Truls;


    -damaging exercise', primarily eccentric exercise. We review the evidence for the notion that the degree of muscle damage is related to the magnitude of the cytokine response. In the third and final section, we look at the satellite cell response to a single bout of eccentric exercise, as well as the role of the...... variation in individual responses to a given exercise should, however be expected. The link between cytokine and satellite cell responses and exercise-induced muscle damage is not so clear The systemic cytokine response may be linked more closely to the metabolic demands of exercise rather than muscle...... damage. With the exception of IL-6, the sources of systemic cytokines following exercise remain unclear The satellite cell response to severe muscle damage is related to regeneration, whereas the biological significance of satellite cell proliferation after mild damage or non-damaging exercise remains...

  20. Virtual Satellite Integration Environment Project

    National Aeronautics and Space Administration — An integrated environment for rapid design studies of small satellite missions will be developed. This environment will be designed to streamline processes at the...

  1. Visual Data Analysis for Satellites

    Lau, Yee; Bhate, Sachin; Fitzpatrick, Patrick


    The Visual Data Analysis Package is a collection of programs and scripts that facilitate visual analysis of data available from NASA and NOAA satellites, as well as dropsonde, buoy, and conventional in-situ observations. The package features utilities for data extraction, data quality control, statistical analysis, and data visualization. The Hierarchical Data Format (HDF) satellite data extraction routines from NASA's Jet Propulsion Laboratory were customized for specific spatial coverage and file input/output. Statistical analysis includes the calculation of the relative error, the absolute error, and the root mean square error. Other capabilities include curve fitting through the data points to fill in missing data points between satellite passes or where clouds obscure satellite data. For data visualization, the software provides customizable Generic Mapping Tool (GMT) scripts to generate difference maps, scatter plots, line plots, vector plots, histograms, timeseries, and color fill images.

  2. Commercial satellite broadcasting for Europe

    Forrest, J. R.


    A review is presented of the current television broadcasting situation in European countries, which involves a varied mix of terrestrial VHF or UHF systems and cable networks. A small market has emerged in Europe for receivers using the low-power telecommunications satellite transmission between the program providers and cable network companies. This is expected to change with the launch of medium-power pan-European telecommunication satellites (e.g. ASTRA, EUTELSAT II), which are now directly addressing the market of home reception. DBS (direct broadcast satellite) in the UK, using the D-MAC transmission standard, will offer three additional television channels, data broadcasting services, and a planned evolution to compatible forms of wide-screen, high-definition television. Comments are given on receiver and conditional access system standardization. Some views are expressed on satellite broadcasting as part of an overall broadcasting framework for the future.

  3. Virtual Satellite Integration Environment Project

    National Aeronautics and Space Administration — Advatech Pacific proposes to develop a Virtual Satellite Integration Environment (VSIE) for the NASA Ames Mission Design Center. The VSIE introduces into NASA...

  4. Biogeography based Satellite Image Classification

    Panchal, V K; Kaur, Navdeep; Kundra, Harish


    Biogeography is the study of the geographical distribution of biological organisms. The mindset of the engineer is that we can learn from nature. Biogeography Based Optimization is a burgeoning nature inspired technique to find the optimal solution of the problem. Satellite image classification is an important task because it is the only way we can know about the land cover map of inaccessible areas. Though satellite images have been classified in past by using various techniques, the researchers are always finding alternative strategies for satellite image classification so that they may be prepared to select the most appropriate technique for the feature extraction task in hand. This paper is focused on classification of the satellite image of a particular land cover using the theory of Biogeography based Optimization. The original BBO algorithm does not have the inbuilt property of clustering which is required during image classification. Hence modifications have been proposed to the original algorithm and...

  5. Le miroir aux alouettes : destin sociologique des images du nu indigène

    Pouillon, François; Mégnin, Michel


    Les cartes postales de nus indigènes d’époque coloniale ont fait l’objet depuis les années 1980 d’un certain nombre d’ouvrages qui, au prétexte d’en condamner la fabrication et la diffusion, paradoxalement, les exhibent. Les présentations, rédigées par des auteurs fortement inscrits dans une diaspora intellectuelle, témoignent de la persistance de certains rapports des sociétés maghrébines d’aujourd’hui à leurs femmes. On y retrouve la forte pulsion méditerranéenne à l’endogamie, soulignée en...

  6. Radio interferometry and satellite tracking

    Kawase, Seiichiro


    Worldwide growth of space communications has caused a rapid increase in the number of satellites operating in geostationary orbits, causing overcrowded orbits. This practical resource is designed to help professionals overcome this problem. This timely book provides a solid understanding of the use of radio interferometers for tracking and monitoring satellites in overcrowded environments. Practitioners learn the fundamentals of radio interferometer hardware, including antennas, receiving equipment, signal processing and phase detection, and measurement accuracies. This in-depth volume describ

  7. NEGESAR: NEw GEneration Satellite Architecture

    Boer, Fabrizio; Borghesi, Giancarlo


    Reduce to the minimum any analog-based system on board the next generation satellites and replace them with the more performing and reliable digital platforms shall be the challenge for all the Space Business World in the next decade. The micro-size NEGESAT Company (2 experienced Space Engineers) has launched, since early 99, the project called NEGESAR (NEw GEneration Satellite ARchitecture) aiming at this objective: to give the Space User a way to launch active and complex Electronic Equipme...

  8. TERSat: Trapped Energetic Radiation Satellite

    Clements, Emily; Alvisio, Bruno; Babuscia, Alessandra; Casas, Zachary; Coffee, Brian; Giblin, Sydney; Hallock, Laura; Kingsbury, Ryan; Leaman, Michael; Lynch, Naomi; O'Connor, Michael; Qian, Elizabeth; Schmidt, Frank; de Soria-Santacruz, Maria; Sotomayor, Lionel


    Radiation damage caused by interactions with high-energy particles in the Van Allen Radiation Belts is a leading cause of component failures for satellites in low and medium Earth orbits (LEO, MEO). Very Low Frequency (VLF) electromagnetic waves have been shown to couple energy to high energy radiation belt particles and change their properties. For example, data from the IMAGE (Imager for Magnetopause-to-Aurora Global Exploration) satellite suggest that the gap between the inner ...

  9. Existence of undiscovered Uranian satellites

    Structure in the Uranian ring system as observed in recent occultations may contain indirect evidence for the existence of undiscovered satellites. Using the Alfven and Arrhenius (1975, 1976) scenario for the formation of planetary systems, the orbital radii of up to nine hypothetical satellites interior to Miranda are computed. These calculations should provide interesting comparisons when the results from the Voyager 2 encounter with Uranus are made public. 15 refs., 1 fig., 1 tab

  10. Gaussian Entanglement Distribution via Satellite

    Hosseinidehaj, Nedasadat; Malaney, Robert


    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 thi...

  11. Satellite medical centers project

    Aggarwal, Arvind


    World class health care for common man at low affordable cost: anywhere, anytime The project envisages to set up a national network of satellite Medical centers. Each SMC would be manned by doctors, nurses and technicians, six doctors, six nurses, six technicians would be required to provide 24 hour cover, each SMC would operate 24 hours x 7 days. It would be equipped with the Digital telemedicine devices for capturing clinical patient information and investigations in the form of voice, images and data and create an audiovisual text file - a virtual Digital patient. Through the broad band connectivity the virtual patient can be sent to the central hub, manned by specialists, specialists from several specialists sitting together can view the virtual patient and provide a specialized opinion, they can see the virtual patient, see the examination on line through video conference or even PCs, talk to the patient and the doctor at the SMC and controlle capturing of information during examination and investigations of the patient at the SMC - thus creating a virtual Digital consultant at the SMC. Central hub shall be connected to the doctors and consultants in remote locations or tertiary care hospitals any where in the world, thus creating a virtual hub the hierarchical system shall provide upgradation of knowledge to thedoctors in central hub and smc and thus continued medical education and benefit the patient thru the world class treatment in the smc located at his door step. SMC shall be set up by franchisee who shall get safe business opportunity with high returns, patients shall get Low cost user friendly worldclass health care anywhere anytime, Doctors can get better meaningful selfemplyment with better earnings, flexibility of working time and place. SMC shall provide a wide variety of services from primary care to world class Global consultation for difficult patients.

  12. ARJIS satellite demonstration project

    Severance, Steve; Williams, Carl


    In 2003, the California Space Authority (CSA) was provided funding by the U. S. Congress through the Defense Appropriations Act to develop a project that would demonstrate the U.S. space enterprise capability that would contribute to the effectiveness of those engaged in Homeland Security. The project was given broad latitude in selecting the area of Homeland Security to be addressed and the nature of the space technology to be applied. CSA became aware of a nascent law enforcement data-sharing project in the San Diego region known as the Automated Regional Justice Information System (ARJIS). First developed by the police departments in San Diego, ARJIS is an innovative system that shares criminal justice information among 50 federal, state, and local agencies. ARJIS was completing a pilot project that enabled officers to receive information on handheld computers, which was transmitted wirelessly through cellular networks. The accessed information came from several databases that collectively contained the entire region's crime and arrest reports, traffic citations, and incidents, as well as state and county wants and warrants. The fundamental limitations that plague all cellular-based devices caught CSA's attention and resulted in a cooperative effort to harden the communications link between the patrol officer and critical data. The principal goal of the SATCOM development task was to create a proof-of-concept application that would use SATCOM links to augment the current ARJIS handheld wireless (cellular) capability. The successful technical demonstration and the positive support for satellite communications from the law enforcement community showed that this project filled a need-both for improved information sharing and for highly reliable communications systems.

  13. A satellite for demonstration of Panel Extension Satellite (PETSAT)

    Sugawara, Yoshiki; Sahara, Hironori; Nakasuka, Shinichi; Greenland, Stephen; Morimoto, Takeshi; Koyama, Kanichi; Kobayashi, Chisato; Kikuchi, Hideaki; Okada, Takanori; Tanaka, Hidenori


    This paper presents the current status, configuration, architecture, and key technologies of SOHLA-2, the demonstration mission of the PETSAT (Panel ExTension SATellite) concept. The PETSAT proposal is for a modular satellite consisting of any number of unfolding functional panels. These panels are designed around an open architecture and connected through standardized interfaces. The interfaces between panels incorporate a reliable "plug-in" format, such that when combined, the integrated system takes on the intended satellite function in a redundant and distributed manner. By combining the different panel types in any number and configuration, flexibility to mission requirements is achieved. Some panels for performing basic satellite functions will be available as commercial-off-the-shelf components, and others custom developed dependent on the mission. During launch these panels are stowed in a folded low volume configuration, which is then extended on-orbit, realizing a satellite with a large area for the mounting of solar arrays, mission systems, extensible booms, or any other components. SOHLA-2 is both a concept demonstration and a lightning detection mission in the VHF band. It weighs less than 50 kg and consists of six panels: communication, attitude control, propulsion, mission, experiment and bus function. The bus function panel is based on the successful Cubesat XI developed at the University of Tokyo and this acts as the manager of the technology demonstration aspects for the mission. By basing the architecture upon a proven technology, the reliability of the satellite is increased. It is intended that the satellite be launched in early 2008.



    China placed 2 scientific experiment satellites into preset orbits atop a LM-4B launch vehicle on Sept. 9, 2004. A LM-4B blasted off at 7:14 am from Taiyuan Satellite Launch Center in Shanxi Province. Sources from the Xi'an Satellite Monitor and Control Center said that one satellite,

  15. China Launches First Ever Nano-satellite



    China successfully launched two scientific satellites, including a nano-satellite for the first time, heralding a breakthrough in space technology. A LM-2C rocket carrying Nano-Satellite I (NS-1), which weighs just 25kg and an Experiment Satellite I, weighing 204kg blasted off at 11:59 p.m. on April 18,

  16. Geostationary meteorological satellite systems - An overview

    Blersch, Donald J.; Probert, Todd C.

    Past and present geosynchronous meteorological satellites developed in the USA, Europe, Japan, India, and the Soviet Union are reviewed. Particular attention is given to the Applications Technology Satellite Program, GOES and SMS/GOES, METEOSAT, GMS/Himawari, the Indian National Satellite, and a Soviet geostationary meteorological satellite program, GOMS.

  17. Fast Development Of China's Small Satellite Industry

    Sun Hongjin


    @@ China Spacesat Co., Ltd of China Academy of Space Technology (CAST) recently said, along with the successful launch of HJ-1A/B for the environment and disaster monitoring and forecasting small satellite constellation and after years of efforts, small satellite development technology has achieved fruitful results, and the development status has been greatly improved.China's small satellite technology has realized a great-leap-forward in development from a single satellite model to series model, from the satellite program to space industry. China has explored a development road for China's small satellite industrialization, and a modern small satellite development base has resulted.



    China on Sept.25 recovered its 19th recoverable sci-tech experimental satellite 27 days after the satellite orbited in space. The satellite, which was launched on Aug.29 from the Jiuquan Satellite Launch Center in Gansu Province, northwest China, touched the ground at 7:55 a.m.on Sept.25. The satellite, atop a Long March 2C carrier rocket, is mainly for

  19. Using Cell Phones From Satellites

    Horan, Stephen


    During the past several years, an interest has grown in using commercial telecommunications techniques to supply Telemetry and Command (T&C) services. Recently, the National Aeronautics and Space Administration (NASA) Space Operations Management Office (SOMO) has outlined plans to utilize satellite-based telecommunications services to support space operations in space missions over the next several decades. NASA currently obtains the bulk of its telecommunications services for earth-orbiting satellites via the existing government-owned and controlled Space Network (SN) system. This system consists of the constellation of Tracking and Data Relay Satellites (TDRS) in Geostationary Earth Orbit (GEO) and the associated ground terminals and communications intrastructure. This system is valuable and effective for scientific satellites costing over one million dollars. However, for smaller satellites, this system becomes problematic due to the cost of transponders and support infrastructure. The nominal transponders for using the TDRS cannot be obtained for a cost in dollars, and size, weight, or power that the 3 Corner Satellite project can afford. For these types of nanosatellite missions, alternatives that fit the mission cost and satellite profiles are needed. In particular, low-cost access using existing commercial infrastructure would be useful to mission planners. In particular, the ability to obtain low data rate T&C services would be especially valuable. The nanosatellites generally have low T&C requirements and therefore would benefit from using commercial services that could operate in the 2400 bps - 9600 bps range, especially if contact times longer than the 5 - 10 minute ground station passes could be found.

  20. VLBI observations of geosynchronous satellites

    Shu, Fengchun; Zhang, Xiuzhong; Zheng, Weimin

    The principle of determining spacecraft angular position with differential VLBI (Very Long Baseline Interferometry) technique is described. The first domestic differential VLBI observations of geosynchronous satellites were performed with participations of Shanghai, Urumqi and Kunming stations. Three strong quasars within angular separation of 15° from target satellites were selected as reference radio sources. The main purpose of such observations is to obtain interferometric fringes of the satellites, and to estimate accuracy of differential VLBI observations. A 2-station FX type correlator at SHAO (Shanghai Astronomical Observatory) was used to do cross-correlations of radio signals in MK3A-C tape format. Strong fringes of the satellites were detected to all stations. The precision of time delay and rate was derived from the correlator output. Based on system errors analysis, we estimated that ΔDOR (Delta Differential One-way Ranging) error was about 41 cm, and ΔDOD (Delta Differential One-way Doppler) error was about 0.148mm/s, which corresponded, respectively, to the position error of 8m and the velocity error of 2.8mm/s for the geosynchronous satellite on the plane of sky.

  1. Space Solar Power: Satellite Concepts

    Little, Frank E.


    Space Solar Power (SSP) applies broadly to the use of solar power for space related applications. The thrust of the NASA SSP initiative is to develop concepts and demonstrate technology for applying space solar power to NASA missions. Providing power from satellites in space via wireless transmission to a receiving station either on earth, another celestial body or a second satellite is one goal of the SSP initiative. The sandwich design is a satellite design in which the microwave transmitting array is the front face of a thin disk and the back of the disk is populated with solar cells, with the microwave electronics in between. The transmitter remains aimed at the earth in geostationary orbit while a system of mirrors directs sunlight to the photovoltaic cells, regardless of the satellite's orientation to the sun. The primary advantage of the sandwich design is it eliminates the need for a massive and complex electric power management and distribution system for the satellite. However, it requires a complex system for focusing sunlight onto the photovoltaic cells. In addition, positioning the photovoltaic array directly behind the transmitting array power conversion electronics will create a thermal management challenge. This project focused on developing designs and finding emerging technology to meet the challenges of solar tracking, a concentrating mirror system including materials and coatings, improved photovoltaic materials and thermal management.

  2. Commercial applications of satellite oceanography

    Montgomery, D. R.


    It is shown that in the next decade the oceans' commercial users will require an operational oceanographic satellite system or systems capable of maximizing real-time coverage over all ocean areas. Seasat studies suggest that three spacecraft are required to achieve this. Here, the sensor suite would measure surface winds, wave heights (and spectral energy distribution), ice characteristics, sea-surface temperature, ocean colorimetry, height of the geoid, salinity, and subsurface thermal structure. The importance of oceanographic data being distributed to commercial users within two hours of observation time is stressed. Also emphasized is the importance of creating a responsive oceanographic satellite data archive. An estimate of the potential dollar benefits of such an operational oceanographic satellite system is given.

  3. Gaussian Entanglement Distribution via Satellite

    Hosseinidehaj, Nedasadat


    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...

  4. The Mexican national satellite system

    Sanchez Ruiz, M. E.; Briskman, R. D.


    The satellites, tracking, telemetry, command, and monitoring facilities, and the earth station complex for the Mexican national satellite system, Morelos, are described. The spacecraft are intended to provide educational television, rural telephony, data transmission, and business and industrial services. Scheduled for 1985 launch, the satellites will be placed in GEO and use the C and Ku bands with 12 narrow band and six wideband transponders. Spin-stabilized and solar cell powered, the functional mass will be 666 kg, including propellant. The solar panels will provide 940 W of power and 830 W will be available from NiCd batteries during eclipse conditions. The earth station will be located at Iztapalapa, which will have a 12 m antenna, redundant uplink and downlink radios, and command and ranging equipment. Back-up capability will be provided by a station at Tulancingo. Ku band and C band stations are in planning.

  5. Dark Matter tested with satellites

    Combes, F


    Recently, the distribution of velocity dispersion as far as 400kpc around red isolated galaxies was derived from statistical studies of satellites in the SDSS (Klypin & Prada 2009). This could help to constrain dark matter models at intermediate scales. We compare the predictions of different DM distributions, LCDM with NFW or cored profiles, and also modified gravity models, with observations. It is shown how the freedom in the various parameters (radial distribution of satellites, velocity anisotropy, external field effect), prevents to disentangle the models, which all can give pretty good fits to the data. In all cases, realistic radial variations of velocity anisotropy are used for the satellites, and a constant stellar-mass to light ratio for the host galaxies.

  6. Satellite Data Transmission (SDT) requirement

    Chie, C. M.; White, M.; Lindsey, W. C.


    An 85 Mb/s modem/codec to operate in a 34 MHz C-band domestic satellite transponder at a system carrier to noise power ratio of 19.5 dB is discussed. Characteristics of a satellite channel and the approach adopted for the satellite data transmission modem/codec selection are discussed. Measured data and simulation results of the existing 50 Mbps link are compared and used to verify the simulation techniques. Various modulation schemes that were screened for the SDT are discussed and the simulated performance of two prime candidates, the 8 PSK and the SMSK/2 are given. The selection process that leads to the candidate codec techniques are documented and the technology of the modem/codec candidates is assessed. Costs of the modems and codecs are estimated.

  7. Small satellites and their regulation

    Jakhu, Ram S


    Since the launch of UoSat-1 of the University of Surrey (United Kingdom) in 1981, small satellites proved regularly to be useful, beneficial, and cost-effective tools. Typical tasks cover education and workforce development, technology demonstration, verification and validation, scientific and engineering research as well as commercial applications. Today the launch masses range over almost three orders of magnitude starting at less than a kilogram up to a few hundred kilograms, with budgets of less than US$ 100.00 and up to millions within very short timeframes of sometimes less than two years. Therefore each category of small satellites provides specific challenges in design, development and operations. Small satellites offer great potentials to gain responsive, low-cost access to space within a short timeframe for institutions, companies, regions and countries beyond the traditional big players in the space arena. For these reasons (particularly the low cost of construction, launch and operation), small (m...

  8. Reinventing the Solar Power Satellite

    Landis, Geoffrey A.


    The selling price of electrical power varies with time. The economic viability of space solar power is maximum if the power can be sold at peak power rates, instead of baseline rate. Price and demand of electricity was examined from spot-market data from four example markets: New England, New York City, suburban New York, and California. The data was averaged to show the average price and demand for power as a function of time of day and time of year. Demand varies roughly by a factor of two between the early-morning minimum demand, and the afternoon maximum; both the amount of peak power, and the location of the peak, depends significantly on the location and the weather. The demand curves were compared to the availability curves for solar energy and for tracking and non-tracking satellite solar power systems in order to compare the market value of terrestrial and solar electrical power. In part 2, new designs for a space solar power (SSP) system were analyzed to provide electrical power to Earth for economically competitive rates. The approach was to look at innovative power architectures to more practical approaches to space solar power. A significant barrier is the initial investment required before the first power is returned. Three new concepts for solar power satellites were invented and analyzed: a solar power satellite in the Earth-Sun L2 point, a geosynchronous no-moving parts solar power satellite, and a nontracking geosynchronous solar power satellite with integral phased array. The integral-array satellite had several advantages, including an initial investment cost approximately eight times lower than the conventional design.

  9. Natural Satellite Ephemerides at JPL

    Jacobson, Robert Arthur; Brozovic, Marina


    There are currently 176 known natural planetary satellites in the solar system; 150 are officially recognized by the IAU and 26 have IAU provisional designations. We maintain ephemerides for all of the satellites at NASA's Jet Propulsion Laboratory (JPL) and make them available electronically through the On-Line Solar System Data Service known as Horizons( and in the form of generic Spice Kernels (SPK files) from NASA's Navigation and Ancillary Information Facility ( General satellite information such as physical constants and descriptive orbital elements can be found on the JPL Solar System Dynamics Website ( JPL's ephemerides directly support planetary spacecraft missions both in navigation and science data analysis. They are also used in general scientific investigations of planetary systems. We produce the ephemerides by fitting numerically integrated orbits to observational data. Our model for the satellite dynamics accounts for the gravitational interactions within a planetary system and the external gravitational perturbations from the Sun and planets. We rely on an extensive data set to determine the parameters in our dynamical models. The majority of the observations are visual, photographic, and CCD astrometry acquired from Earthbased observatories worldwide and the Hubble Space Telescope. Additional observations include optical and photoelectric transits, eclipses, occultations, Earthbased radar ranging, spacecraft imaging,and spacecraft radiometric tracking. The latter data provide information on the planet and satellite gravity fields as well as the satellite position at the times of spacecraft close encounters. In this paper we report on the status of the ephemerides and our plan for future development, specifically that in support of NASA's Juno, Cassini, and New Horizons missions to Jupiter, Saturn, and Pluto, respectively.

  10. Small satellite solar array substrate

    Fiore, John N.; Rosanova, Giulio


    The SMall EXplorer (SMEX) Fast Auroral SnapshoT (FAST) spacecraft was developed to investigate plasma physics of auroral phenomena at high orbital altitude. The FAST satellite comprises a variety of deployable booms with sensors on the ends, and instruments that protrude from the main body of the spacecraft to obtain the plasma and electromagnetic fields data. This required the plasma disturbance around the satellite to be kept to a minimum. A non deployable, body mounted solar array was implemented. This led to the design of a light weight solar array substrate with a high degree of structural integrity.

  11. Telepresence systems for satellite servicing

    Telepresence system concepts for satellite servicing are described which are designed to perform complex tasks at remote worksites. Required performance characteristics are developed for specific satellite service functions, and technology issues are identified. Concepts with the operator both nearby and at a great distance from the worksite, with resulting significant time delays, are addressed. A laboratory program established to support the development of such systems is described and preliminary test conclusions are presented. Technology developments required to resolve outstanding technical issues are identified and associated future flight test programs are discussed

  12. Chameleon gravity and satellite geodesy

    Morris, J R


    We consider the possibility of the detection of a chameleon effect by an earth orbiting satellite such as LAGEOS, and possible constraints that might be placed on chameleon model parameters. Approximate constraints presented here result from using a simple monopole approximation for the gravitational field of the earth, along with results from the Khoury-Weltman chameleon model, solar system constraints obtained from the Cassini mission, and parameter bounds obtained from the LAGEOS satellite. It is furthermore suggested that a comparison of ground-based and space-based multipole moments of the geopotential could reveal a possible chameleon effect.

  13. Satellite voice broadcast system study, volume 2

    Horstein, M.


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

  14. Electric propulsion for small satellites

    Propulsion is required for satellite motion in outer space. The displacement of a satellite in space, orbit transfer and its attitude control are the task of space propulsion, which is carried out by rocket engines. Electric propulsion uses electric energy to energize or accelerate the propellant. The electric propulsion, which uses electrical energy to accelerate propellant in the form of plasma, is known as plasma propulsion. Plasma propulsion utilizes the electric energy to first, ionize the propellant and then, deliver energy to the resulting plasma leading to plasma acceleration. Many types of plasma thrusters have been developed over last 50 years. The variety of these devices can be divided into three main categories dependent on the mechanism of acceleration: (i) electrothermal, (ii) electrostatic and (iii) electromagnetic. Recent trends in space exploration associate with the paradigm shift towards small and efficient satellites, or micro- and nano-satellites. A particular example of microthruster considered in this paper is the micro-cathode arc thruster (µCAT). The µCAT is based on vacuum arc discharge. Thrust is produced when the arc discharge erodes some of the cathode at high velocity and is accelerated out the nozzle by a Lorentz force. The thrust amount is controlled by varying the frequency of pulses with demonstrated range to date of 1–50 Hz producing thrust ranging from 1 µN to 0.05 mN. (paper)

  15. Electric propulsion for small satellites

    Keidar, Michael; Zhuang, Taisen; Shashurin, Alexey; Teel, George; Chiu, Dereck; Lukas, Joseph; Haque, Samudra; Brieda, Lubos


    Propulsion is required for satellite motion in outer space. The displacement of a satellite in space, orbit transfer and its attitude control are the task of space propulsion, which is carried out by rocket engines. Electric propulsion uses electric energy to energize or accelerate the propellant. The electric propulsion, which uses electrical energy to accelerate propellant in the form of plasma, is known as plasma propulsion. Plasma propulsion utilizes the electric energy to first, ionize the propellant and then, deliver energy to the resulting plasma leading to plasma acceleration. Many types of plasma thrusters have been developed over last 50 years. The variety of these devices can be divided into three main categories dependent on the mechanism of acceleration: (i) electrothermal, (ii) electrostatic and (iii) electromagnetic. Recent trends in space exploration associate with the paradigm shift towards small and efficient satellites, or micro- and nano-satellites. A particular example of microthruster considered in this paper is the micro-cathode arc thruster (µCAT). The µCAT is based on vacuum arc discharge. Thrust is produced when the arc discharge erodes some of the cathode at high velocity and is accelerated out the nozzle by a Lorentz force. The thrust amount is controlled by varying the frequency of pulses with demonstrated range to date of 1-50 Hz producing thrust ranging from 1 µN to 0.05 mN.

  16. China Satcom: Innovating Satellite Communication


    China Satellite Communications Group Corporation (China Satcom) is a state-owned large-sized key enterprise formally established on Dec. 19, 2001 according to the general deployment of the State Council on telecommunication system reform. Relying on its complete service system, China Satcom provides various users with specialized and high quality information communication service.

  17. China's Meteorological Satellite Application System

    Zhang Jiashen


    @@ (Continued) Applications In Global Environment And Natural Disaster Monitoring 1) Application in world crop yield estimation China is now one of the few nations in the world that can provide operational service with both GEO and polar-orbit meteorological satellites.

  18. Introductory Course on Satellite Navigation

    Giger, Kaspar; Knogl, J. Sebastian


    Satellite navigation is widely used for personal navigation and more and more in precise and safety-critical applications. Thus, the subject is suited for attracting the interest of young people in science and engineering. The practical applications allow catching the students' attention for the theoretical background. Educational material on the…

  19. Overview of the meteorological satellite

    Kodaira, Nobuhiko


    The geostational meteorological satellite (Himawari) GMS-3 is now in activity. The next satellite GMS-4-4 is to be launched in 1989. GMS is a geostational meteorological satellite with rotates at 100 rpm by the spin stabilization system. The spin axis is perpendicular to the orbital plane across the earth. For imaging of the earth, GMS scans the earth from the west to the east, with a visible IR radiator. With the computer recently introduced, the observation can be successively made every 1 hour interval in the normal condition. The cloud-moving image obtained by the successive observation shows the cloud movement more smoothly, as compared with that obtained by conventional observation every 3 hour interval. The main meteorological observation items which can not be achieved by the present meteorological satellite include rainfall and ground atmospheric pressure. TRMM for measuring rainfalls is under co-investigation of U.S.A. and Japan. Measurement of atomospheric pressure has not reached the practical use stage yet. Typical measuring method utilizes the O/sub 2/ absorption wavelength range with a microwave. (6 figs, 2 tabs, 4 refs)

  20. Small satellites for tropical applications

    Montpetit, Marie-Jose; Bonn, Ferdinand


    A number of mission studies were performed to assess the suitability of small satellite systems for tropical data acquisition. These studies took into account the specifics of the tropical user communities and were focused on remote sensing and resource management issues. The requirements and potential solutions for four application areas are discussed. For monitoring of forest and agricultural vegetation, a small synthetic aperture radar is considered with P, C, or X band imaging, possibly supplemented by a high resolution multispectral imager. The radar would have the capability to monitor below cloud cover which is often found in tropical regions. Optical, microwave, or spectrographic imaging would also be useful in small satellites for disaster monitoring (notably of floods), land management, and air pollution monitoring. A small satellite with data storage and forwarding capability is also envisioned to collect data from dependable, low-power, and low-cost ground sensors via a simple ultrahigh frequency uplink and download the data on a very high frequency downlink. All the small satellites would be launched in low inclination orbits to ensure a number of consecutive passes over the targeted tropical area.

  1. Monitoring Global Temperatures From Satellites

    Spencer, Roy W.; Christy, John R.


    Report provides evidence that passive microwave radiometry from satellites provides more-precise information on atmospheric temperatures than sparse distribution of thermometers. Accurate temperatures needed for detection of "greenhouse" warming, evaluation of computer models of change in climate, and for understanding important factors in climate system.

  2. MEMOS - Mars Environment Monitoring Satellite

    Ott, T.; Barabash, S.; von Schéele, F.; Clacey, E.; Pokrupa, N.


    The Swedish Institute of Space Physics (IRF) in cooperation with the Swedish Space Corporation (SSC) has conducted first studies on a Mars Environment Monitoring Satellite (MEMOS). The MEMOS microsatellite (mass budget. The low thrust level enables precise and active nutation damping. Moreover the system offers the possibility of implementing active orbit control or formation flight demonstrations at Mars. Attitude will be determined on-board with an accuracy based on MEMS-technology. TM/TC will be relayed via the parent satellite in the UHF frequency range. Therefore the Electra Lite (ELT) Proximity-1 transceiver will autonomously communicate with the parent satellite at inter-satellite ranges 2 kbit/s. The transceiver also implements a coherent transponding mode for orbit determination through two-way Doppler ranging between the parent satellite and MEMOS. In addition ELT is compatible with a future Martian communication and navigation network pursued by NASA, which could be taken advantage of in the future for relaying data or performing ranging via other satellites part of the network. A system design driver for inter-satellite communication at Mars is the high demand of power. This leads to a disk-shape and thus easy to accommodate spacecraft configuration of MEMOS comprising a single sun-pointing solar array favourable in terms of power and spin stability. Multi-junction solar cells, which currently have an efficiency of ~29% under laboratory conditions are a key factor to keep MEMOS solar array area of ~1.15 m2 small compared to the worst case system power requirements of ~105 W. During eclipse periods high-efficient Li-ion batteries (6 x 20 Wh) will ensure power supply. The spacecraft and payload design will incorporate new technology developments such as autonomous navigation, MicroElectroMechanical Systems MEMS, Micro- Opto-ElectroMechanical Systems MOEMS and new materials to achieve low mass at high performance. Thereby it will profit from Swedish

  3. DIORAMA Model of Satellite Body Orientation

    Werley, Kenneth Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    The DIORAMA GPS satellite platform orientation model is described. Satellites need to keep sensors pointed towards the earth and solar panels oriented to face the sun (when not in the earth’s shadow) while they orbit the earth.

  4. Space Environment Deteation of Chinese Meteorological Satellites

    XU Ying; WANG Shijin; ZHU Guangwu; LIANG Jinbao


    This paper presents the space environment detection of Chinese geosynchronous and sun-synchronous meteorological satellites and gives a short perspective of space environment observations on board meteorological satellites.

  5. Satellite Tags- Guam/CNMI EEZ

    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...

  6. Highly Enhanced Risk Management Emergency Satellite

    Dalmeir, Michael; Gataullin, Yunir; Indrajit, Agung;

    HERMES (Highly Enhanced Risk Management Emergency Satellite) is potential European satellite mission for global flood management, being implemented by Technical University Munich and European Space Agency. With its main instrument - a reliable and precise Synthetic Aperture Radar (SAR) antenna...

  7. New Equipment Training Center-Satellite Facility

    Federal Laboratory Consortium — The ARDEC Satellite Facility is a 24-hour on-site military satellite transmission and downlink capability to Southwest Asia and all other military OCONUS and CONUS...

  8. A new small satellite goes into orbit


    @@ On 5 November, 2008,a rocket launched the Chuangxin-1(02), a small satellite built by the Shanghai Engineering Center for MicroSatellite under the CAS Shanghai Institute of Microsystem and Information Technology, into its preset orbit.

  9. RFP for the italien satellite AGILE

    Madsen, Peter Buch; Jørgensen, John Leif; Riis, Troels;


    The document descibes the ASC Star Tracker (performance, functionality, requirements etc.) to the Italian satellite AGILE.......The document descibes the ASC Star Tracker (performance, functionality, requirements etc.) to the Italian satellite AGILE....

  10. Specifics of Small Satellite Propulsion: Part 1

    Zakirov, Vadim; Sweeting, Martin; Erichsen, Peter; Lawrence, Timothy


    Small satellite propulsion is a subject of unique constraints and requirements. Based on University of Surrey experience in small satellite building and operation, these features are listed and explained. Available volume is often identified as the most severe constraint for a small satellite with power and cost being the other two major constraints. Mass is often only of secondary importance for small satellites. Propulsion dry mass fraction for a spacecraft grows upon the system scaling-dow...

  11. User Validation of VIIRS Satellite Imagery

    Don Hillger; Tom Kopp; Curtis Seaman; Steven Miller; Dan Lindsey; Eric Stevens; Jeremy Solbrig; William Straka III; Melissa Kreller; Arunas Kuciauskas; Amanda Terborg


    Visible/Infrared Imaging Radiometer Suite (VIIRS) Imagery from the Suomi National Polar-orbiting Partnership (S-NPP) satellite is the finest spatial resolution (375 m) multi-spectral imagery of any operational meteorological satellite to date. The Imagery environmental data record (EDR) has been designated as a Key Performance Parameter (KPP) for VIIRS, meaning that its performance is vital to the success of a series of Joint Polar Satellite System (JPSS) satellites that will carry this instr...

  12. Mobility Extension for Broadband Satellite Multimedia

    Hu, Y.Fun; Pillai, Prashant; Berioli, Matteo


    This paper presents an extension for Broadband Satellite Multimedia (BSM) to support Mobility Management (MM). To support seamless handovers, mobility related entities are proposed in the Satellite Independent Access Function (SIAF) defined over the SI-SAP interface. This enables the mapping of the mobility related primitives between the higher layer and the satellite dependant lower layers via the Satellite Dependent Access Function (SDAF). The proposed MM architecture incorporates the Media...

  13. Sustained Satellite Missions for Climate Data Records

    Halpern, David


    Satellite CDRs possess the accuracy, longevity, and stability for sustained moni toring of critical variables to enhance understanding of the global integrated Earth system and predict future conditions. center dot Satellite CDRs are a critical element of a global climate observing system. center dot Satellite CDRs are a difficult challenge and require high - level managerial commitment, extensive intellectual capital, and adequate funding.

  14. Small Satellite Space Environments Effects Test Facility

    Dennison, JR; Hartley, Kent; Montierth Phillipps, Lisa; Johnson, Robert; Dekany, Justin; Dyer, James


    A versatile space environments test facility has been designed and built to study the effects on small satellites and system components. Testing for potentially environmental-induced modifications of small satellites is critical to avoid possible deleterious or catastrophic effects over the duration of space missions. This is increasingly more important as small satellite programs have longer mission lifetimes, expand to more hash env...

  15. 14 CFR 141.91 - Satellite bases.


    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Satellite bases. 141.91 Section 141.91... OTHER CERTIFICATED AGENCIES PILOT SCHOOLS Operating Rules § 141.91 Satellite bases. The holder of a... assistant chief instructor is designated for each satellite base, and that assistant chief instructor...

  16. When does a satellite knot fiber?

    Hirasawa, Mikami; Murasugi, Kunio; Silver, Daniel S.


    Necessary and sufficient conditions are given for a satellite knot to be fibered. Any knot $\\tilde k$ embeds in an unknotted solid torus $\\tilde V$ with arbitrary winding number in such a way that no satellite knot with pattern $(\\tilde V, \\tilde k)$ is fibered. In particular, there exist nonfibered satellite knots with fibered pattern and companion knots and nonzero winding number.

  17. China Launches Two Natural Disaster Monitoring Satellites


    @@ China launched two satellites, HJ-1A and HJ-1B, to monitor the environment and natural disasters at 11:25am on September 6 (Beijing time) from the Taiyuan Satellite Launch Center in Shanxi Province. The two satellites are expected to improve the country's ability in the rapid monitoring of environmental changes and reducing calamities.

  18. Processor Units Reduce Satellite Construction Costs


    As part of the effort to build the Fast Affordable Science and Technology Satellite (FASTSAT), Marshall Space Flight Center developed a low-cost telemetry unit which is used to facilitate communication between a satellite and its receiving station. Huntsville, Alabama-based Orbital Telemetry Inc. has licensed the NASA technology and is offering to install the cost-cutting units on commercial satellites.

  19. QRM, Packet Satellites and Spread Spectrum

    Cobb, Stewart


    Digital messaging satellites designed for general use may attract considerable user interest. High interest will mean heavy interference on the satellite uplink channels, which could make the satellite useless. This paper discusses the characteristics of this interference, and proposes a solution using spread-spectrum technology.

  20. An Overview Of Operational Satellites Built By China: Communications Satellites (Part1)

    Guang Bo


    @@ Communications satellite technology has seen great advances since Decemher 1958 when the Americans launched the first experimental communications satellite.Currently, satellite communications account for over 80 percent of the intercontinental communications traffic and 100 percent of international live TV broadcast, while taking part in domestic and regional services. Moreover, the satellite communication service is showing a favorable continuous growth tendency.

  1. Attitude control of a nano satellite


    The CubeSTAR satellite is a student satellite project at the University of Oslo. The main mission is to measure the turbulence in the electron plasma using a novel Multi Needle Langmuir Probe system developed at the University of Oslo. In order to get correct measurements, it’s important that the probes are located in the front of the satellite in the orbit velocity direction. In this thesis, the attitude control problem of the CubeSTAR nano-satellite is the main topic. The satellite wil...

  2. Satellite communications network design and analysis

    Jo, Kenneth Y


    This authoritative book provides a thorough understanding of the fundamental concepts of satellite communications (SATCOM) network design and performance assessments. You find discussions on a wide class of SATCOM networks using satellites as core components, as well as coverage key applications in the field. This in-depth resource presents a broad range of critical topics, from geosynchronous Earth orbiting (GEO) satellites and direct broadcast satellite systems, to low Earth orbiting (LEO) satellites, radio standards and protocols.This invaluable reference explains the many specific uses of

  3. Satellite television analogue and digital reception techniques

    Benoit, Herve


    Satellite television is part of the lives of millions of television viewers worldwide and its influence is set to increase significantly with the launch of digital satellite television services.This comprehensive reference book, written by the author of the highly successful 'Digital Television', provides a technical overview of both analogue and digital satellite TV. Written concisely and thoroughly, it covers all aspects of satellite TV necessary to understand its operation and installation. It also covers the evolution of satellite television, and contains a detailed glossary of tec

  4. Sweeping and shaking dwarf satellites

    Mayer, L; Mayer, Lucio; Wadsley, James


    We present the first high-resolution N-Body/SPH simulations that follow the evolution of low surface brightness disk satellites in a primary halo containing both dark matter and a hot gas component. Tidal shocks turn the stellar disk into a spheroid with low $v/\\sigma$ and remove most of the outer dark and baryonic mass. In addition, by weakening the potential well of the dwarf, tides enhance the effect of ram pressure, and the gas is stripped down to radius three times smaller than the stellar component A very low gas/stars ratio results after several Gyr, similarly to what seen in dwarf spheroidal satellites of the Milky Way and M31.

  5. Desert dust satellite retrieval intercomparison

    E. Carboni


    Full Text Available This work provides a comparison of satellite retrievals of Saharan desert dust aerosol optical depth (AOD during a strong dust event through March 2006. In this event, a large dust plume was transported over desert, vegetated, and ocean surfaces. The aim is to identify and understand the differences between current algorithms, and hence improve future retrieval algorithms. The satellite instruments considered are AATSR, AIRS, MERIS, MISR, MODIS, OMI, POLDER, and SEVIRI. An interesting aspect is that the different algorithms make use of different instrument characteristics to obtain retrievals over bright surfaces. These include multi-angle approaches (MISR, AATSR, polarisation measurements (POLDER, single-view approaches using solar wavelengths (OMI, MODIS, and the thermal infrared spectral region (SEVIRI, AIRS. Differences between instruments, together with the comparison of different retrieval algorithms applied to measurements from the same instrument, provide a unique insight into the performance and characteristics of the various techniques employed. As well as the intercomparison between different satellite products, the AODs have also been compared to co-located AERONET data. Despite the fact that the agreement between satellite and AERONET AODs is reasonably good for all of the datasets, there are significant differences between them when compared to each other, especially over land. These differences are partially due to differences in the algorithms, such as assumptions about aerosol model and surface properties. However, in this comparison of spatially and temporally averaged data, at least as significant as these differences are sampling issues related to the actual footprint of each instrument on the heterogeneous aerosol field, cloud identification and the quality control flags of each dataset.

  6. Satellite altimetry and ocean dynamics

    Fu, Lee Lueng; Le Traon, Pierre-Yves


    This paper provides a summary of recent results derived from satellite altimetry. It is focused on altimetry and ocean dynamics with synergistic use of other remote sensing techniques, in-situ data and integration aspects through data assimilation. Topics include mean ocean circulation and geoid issues, tropical dynamics and large-scale sea level and ocean circulation variability, high-frequency and intraseasonal variability, Rossby waves and mesoscale variability. To cite this article: L.L. ...

  7. Tourism Satellite Account for India

    Rajesh Shukla


    With the growing recognition of tourism as a source of employment generating growth in the country, improved understanding of what tourism is, its role in the economy and its relationship to other parts of the economy is important. The Tourism Satellite Account (TSA) is a new framework recently adopted by the United Nations Statistical Commission that provides an important platform towards forging improved understanding of the structure and role of tourism in the economy. Estimates using the ...

  8. Laser Payloads on Small Satellites

    Lingvay, L.S.; Bowman, A.P.; Wallace, A. S.


    Laser payloads on satellites have the ability to enhance our communications capabilities and information gathering power from space. Implementation of lasers to Lightsats provides one method to assess the effectiveness of these technologies at reduced risk. This paper will focus on the main applications of lasers in space and how laser systems may be adapted to the Lightsat environment. This will include a discussion of the different types of lasers, which types are suitable for space based p...

  9. Marine Corps Tactical Satellite Communications

    Daniel, Walter; Rivas, Gavino; Bruninga, Robert


    A tactical satellite communications exercise using the DARPA Microsats was conducted by Naval Academy personnel at the Quantico Marine Corps Base in Virginia. Midshipmen used a military UHF radio, a modified amateur radio transmitter, and scanner receivers while a station in Annapolis communicated with them. Voice communications were clear and understandable even when the tactical teams were in the woods. Amateur radio operators and scanner enthusiasts around the eastern half of the United St...

  10. Weather Satellite Pictures and How to Obtain Them.

    Petit, Noel J.; Johnson, Philip


    An introduction to satellite meteorology is presented to promote use of live weather satellite photographs in the classroom. Topics addressed include weather satellites, how they work, earth emissions, satellite photography, satellite image analysis, obtaining satellite pictures, and future considerations. Includes sources for materials to…

  11. The Giant Planet Satellite Exospheres

    McGrath, Melissa A.


    Exospheres are relatively common in the outer solar system among the moons of the gas giant planets. They span the range from very tenuous, surface-bounded exospheres (e.g., Rhea, Dione) to quite robust exospheres with exobase above the surface (e.g., lo, Triton), and include many intermediate cases (e.g., Europa, Ganymede, Enceladus). The exospheres of these moons exhibit an interesting variety of sources, from surface sputtering, to frost sublimation, to active plumes, and also well illustrate another common characteristic of the outer planet satellite exospheres, namely, that the primary species often exists both as a gas in atmosphere, and a condensate (frost or ice) on the surface. As described by Yelle et al. (1995) for Triton, "The interchange of matter between gas and solid phases on these bodies has profound effects on the physical state of the surface and the structure of the atmosphere." A brief overview of the exospheres of the outer planet satellites will be presented, including an inter-comparison of these satellites exospheres with each other, and with the exospheres of the Moon and Mercury.

  12. Jupiter and Its Galilean Satellites

    McGrath, Melissa A.


    Jupiter is one of the two most studied planets other than Earth in our Solar System. It is the largest, fastest rotating, has the strongest magnetic field, and an incredibly diverse set of satellites, most prominent of which are the four Galilean satellites discovered in 1610. Io, Europa, Ganymede and Callisto encompass some of the most bizarre environments known in the solar system, from Io, the most volcanically active and perhaps the most inhospitable body known, to Europa, currently thought to be the most likely extraterrestrial abode for habitability, to Ganymede, which is larger than Mercury, and Callisto, which has the oldest surface known in the solar system with the widest array of crater morphologies known. One of the premier areas of scientific return in solar system research in the past 15 years, due in large part to the Galileo mission and observations by the Hubble Space Telescope, has been a remarkable increase in our knowledge about these satellites. Discoveries have been made of tenuous molecular oxygen atmospheres on Europa and Ganymede, a magnetic field and accompanying auroral emissions at the poles of Ganymede, and of ozone and sulfur dioxide embedded in the surfaces of Europa, Ganymede and Callisto. Io's unusual sulfur dioxide atmosphere, including its volcanic plumes and strong electrodynamic interaction with magnetospheric plasma, has finally been quantitatively characterized. This talk will present highlights from the recent discoveries and advances in our understanding of these fascinating objects.

  13. Satellite-based laser windsounder

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project''s primary objective is to determine the technical feasibility of using satellite-based laser wind sensing systems for detailed study of winds, aerosols, and particulates around and downstream of suspected proliferation facilities. Extensive interactions with the relevant operational organization resulted in enthusiastic support and useful guidance with respect to measurement requirements and priorities. Four candidate wind sensing techniques were evaluated, and the incoherent Doppler technique was selected. A small satellite concept design study was completed to identify the technical issues inherent in a proof-of-concept small satellite mission. Use of a Mach-Zehnder interferometer instead of a Fabry-Perot would significantly simplify the optical train and could reduce weight, and possibly power, requirements with no loss of performance. A breadboard Mach-Zehnder interferometer-based system has been built to verify these predictions. Detailed plans were made for resolving other issues through construction and testing of a ground-based lidar system in collaboration with the University of Wisconsin, and through numerical lidar wind data assimilation studies

  14. Detection and surveillance by satellite

    In parallel with the conventional methods used for detecting nuclear explosions and revealing signs of proliferation and, as a consequence, the monitoring of human activities. Among the main advantages of satellites is their ability to carry out non-intrusive observations of any part of the Earth's surface at all times, while remaining in full compliance with legal requirements. Satellite-based detection is based on the electromagnetic pulse (EMP) and various optical effects. The modification of signals as they traverse the atmosphere and ionosphere should also be taken into account, but such changes in no way hinder the detection. Ultra-high frequencies are the most suitable for detection since they are less affected by the ionosphere. Signals propagated in this way are characteristic and can be distinguished from those due to lightning storms. However, some important questions arise because of the recent discovery of a new type of lightning which propagates from the tops of clouds towards the ionosphere. The electromagnetic signal in some respects is similar to that produced by an explosion. Site surveillance depends on the analysis and processing of satellite imagery such as obtained by SPOT, Landsat or ERSI. More precise measurements obtained by interferometry (ERSI) enable the observation of small-amplitude strains with can lead to the discrimination of natural seismic events from nuclear explosions. (authors)

  15. Satellite-based laser windsounder

    Schultz, J.F.; Czuchlewski, S.J.; Quick, C.R. [and others


    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project`s primary objective is to determine the technical feasibility of using satellite-based laser wind sensing systems for detailed study of winds, aerosols, and particulates around and downstream of suspected proliferation facilities. Extensive interactions with the relevant operational organization resulted in enthusiastic support and useful guidance with respect to measurement requirements and priorities. Four candidate wind sensing techniques were evaluated, and the incoherent Doppler technique was selected. A small satellite concept design study was completed to identify the technical issues inherent in a proof-of-concept small satellite mission. Use of a Mach-Zehnder interferometer instead of a Fabry-Perot would significantly simplify the optical train and could reduce weight, and possibly power, requirements with no loss of performance. A breadboard Mach-Zehnder interferometer-based system has been built to verify these predictions. Detailed plans were made for resolving other issues through construction and testing of a ground-based lidar system in collaboration with the University of Wisconsin, and through numerical lidar wind data assimilation studies.

  16. Satellite Attitude Control System Simulator

    G.T. Conti


    Full Text Available Future space missions will involve satellites with great autonomy and stringent pointing precision, requiring of the Attitude Control Systems (ACS with better performance than before, which is function of the control algorithms implemented on board computers. The difficulties for developing experimental ACS test is to obtain zero gravity and torque free conditions similar to the SCA operate in space. However, prototypes for control algorithms experimental verification are fundamental for space mission success. This paper presents the parameters estimation such as inertia matrix and position of mass centre of a Satellite Attitude Control System Simulator (SACSS, using algorithms based on least square regression and least square recursive methods. Simulations have shown that both methods have estimated the system parameters with small error. However, the least square recursive methods have performance more adequate for the SACSS objectives. The SACSS platform model will be used to do experimental verification of fundamental aspects of the satellite attitude dynamics and design of different attitude control algorithm.

  17. Configurable software for satellite graphics

    Hartzman, P D


    An important goal in interactive computer graphics is to provide users with both quick system responses for basic graphics functions and enough computing power for complex calculations. One solution is to have a distributed graphics system in which a minicomputer and a powerful large computer share the work. The most versatile type of distributed system is an intelligent satellite system in which the minicomputer is programmable by the application user and can do most of the work while the large remote machine is used for difficult computations. At New York University, the hardware was configured from available equipment. The level of system intelligence resulted almost completely from software development. Unlike previous work with intelligent satellites, the resulting system had system control centered in the satellite. It also had the ability to reconfigure software during realtime operation. The design of the system was done at a very high level using set theoretic language. The specification clearly illustrated processor boundaries and interfaces. The high-level specification also produced a compact, machine-independent virtual graphics data structure for picture representation. The software was written in a systems implementation language; thus, only one set of programs was needed for both machines. A user can program both machines in a single language. Tests of the system with an application program indicate that is has very high potential. A major result of this work is the demonstration that a gigantic investment in new hardware is not necessary for computing facilities interested in graphics.

  18. Binning of satellite magnetic anomalies

    Goyal, H. K.; Vonfrese, R. R. B.; Hinze, W. J.


    Crustal magnetic anomaly signals over satellite orbits were simulated to investigate numerical averaging as an anomaly estimator. Averaging as an anomaly estimator involves significant problems concerning spatial and amplitude smoothing of the satellite magnetic observations. The results of simulations suggest that the error of numerical averaging constitutes a small and relatively minor component of the total error-budget of higher orbital anomaly estimates, whereas for lower orbital estimates numerical averaging error increases substantially. As an alternative to numerical averaging, least-squares collocation was investigated and observed to produce substantially more accurate anomaly estimates, particularly as the orbital elevation of prediction was decreased towards the crustal sources. In contrast to averaging, collocation is a significantly more resource-intensive procedure to apply because of the practical, but surmountable problems related to establishing and inverting the covariance matrix for accurate anomaly prediction. However, collocation may be much more effectively used to exploit the anomaly details contained in the lower orbital satellite magnetic data for geologic analysis.

  19. Satellite remote sensing of vegetation

    Mahr, Tobias; Peper, Eva; Schubert, Alexander; Warnach, Simon; Pöhler, Denis; Horbanski, Martin; Beirle, Steffen; Mies, Kornelia; Platt, Ulrich; Wagner, Thomas


    DOAS (Differential Optical Absorption Spectroscopy) allows to determine the concentration of trace gases based on their specific absorptions cross-sections along a light path. Since 1995, this principle is employed successfully on satellite-based instruments like GOME, GOME-2 and SCIAMACHY for the global measurement of stratospheric and tropospheric trace gases like ozone and nitrogen oxides. Usually, spectral signatures from the ground, where a big part of the sunlight is reflected, are neglected in the evaluation. This can lead to errors in the trace gas determination. However, these structures offer the opportunity to identify surface properties of the earth and different types of vegetation. To analyse spectral reflectance properties, high resolved reflection spectra (FWHM 0.29 nm) from 95 plants were measured between 350 and 1050 nm. They can serve as a basis for the analysis of satellite data. Including different vegetation reference spectra, it is possible to determine groups of plants with similar optical properties. This allows to derive global maps of the spatio-temporal variation of plant distribution by satellite remote sensing. We present first results of this technique based on SCIAMACHY observations.

  20. Discs of Satellites: the new dwarf spheroidals

    Metz, Manuel; Jerjen, Helmut


    The spatial distributions of the most recently discovered ultra faint dwarf satellites around the Milky Way and the Andromeda galaxy are compared to the previously reported discs-of-satellites (DoS) of their host galaxies. In our investigation we pay special attention to the selection bias introduced due to the limited sky coverage of SDSS. We find that the new Milky Way satellite galaxies follow closely the DoS defined by the more luminous dwarfs, thereby further emphasizing the statistical significance of this feature in the Galactic halo. We also notice a deficit of satellite galaxies with Galactocentric distances larger than 100 kpc that are away from the disc-of-satellites of the Milky Way. In the case of Andromeda, we obtain similar results, naturally complementing our previous finding and strengthening the notion that the discs-of-satellites are optical manifestations of a phase-space correlation of satellite galaxies.

  1. An Algorithm of Inter Satellite Two-Way Time Transfer Based on Mobile Satellite

    Feijiang Huang


    Full Text Available Two-way time transfer is one of the most accurate time synchronization methods applied to spacecrafts and ground stations to carry out time transfer. As this method doesn’t require the knowledge of locations of two satellites in advance and it offsets the negative influence of transmission path and other additional delays, this method has boosted the time synchronization accuracy. However, in the process of time synchronization, this method demands that the aircrafts, who conduct time synchronization, could be relatively static. So it is mainly used in GEO satellites for satellite-ground two-way time transfer. Based on the establishment of mobile satellite mutual visual model, the simulation of satellite mutual visual time on mobile satellite, including IGSO (Inclined Geo Synchronous Orbit satellite and MEO (Medium Earth Orbit satellite, has been conducted. The visual time and the variation range of IGSO-MEO link distance have been gained. The characteristics of the propagation delay of two-way time transfer signals between IGSO satellite and MEO satellite varying with inter satellite range were analyzed and the rule of inter satellite clock offset varying with inter satellite range obtained with this algorithm was deduced. This study presents a inter satellite dynamic two-way time transfer algorithm based on mobile satellite. The high-accuracy inter satellite clock offset is solved through the combination of inter satellite pseudo-range polynomial fitting and clock-offset polynomial fitting. Simulation results showed that with the algorithm the inter satellite time transfer error can be controlled within 1ns. The algorithm can be used high-accuracy time transfer between mobile satellites.

  2. Prediction of GNSS satellite clocks

    This thesis deals with the characterisation and prediction of GNSS-satellite-clocks. A prerequisite to develop powerful algorithms for the prediction of clock-corrections is the thorough study of the behaviour of the different clock-types of the satellites. In this context the predicted part of the IGU-clock-corrections provided by the Analysis Centers (ACs) of the IGS was compared to the IGS-Rapid-clock solutions to determine reasonable estimates of the quality of already existing well performing predictions. For the shortest investigated interval (three hours) all ACs obtain almost the same accuracy of 0,1 to 0,4 ns. For longer intervals the individual predictions results start to diverge. Thus, for a 12-hours- interval the differences range from nearly 10 ns (GFZ, CODE) until up to some 'tens of ns'. Based on the estimated clock corrections provided via the IGS Rapid products a simple quadratic polynomial turns out to be sufficient to describe the time series of Rubidium-clocks. On the other hand Cesium-clocks show a periodical behaviour (revolution period) with an amplitude of up to 6 ns. A clear correlation between these amplitudes and the Sun elevation angle above the orbital planes can be demonstrated. The variability of the amplitudes is supposed to be caused by temperature-variations affecting the oscillator. To account for this periodical behaviour a quadratic polynomial with an additional sinus-term was finally chosen as prediction model both for the Cesium as well as for the Rubidium clocks. The three polynomial-parameters as well as amplitude and phase shift of the periodic term are estimated within a least-square-adjustment by means of program GNSS-VC/static. Input-data are time series of the observed part of the IGU clock corrections. With the estimated parameters clock-corrections are predicted for various durations. The mean error of the prediction of Rubidium-clock-corrections for an interval of six hours reaches up to 1,5 ns. For the 12-hours

  3. Satellite-Based Sunshine Duration for Europe

    Bodo Ahrens


    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.

  4. German telecommunications satellite (Deutscher fernmelde satellit) (DFS-1 and -2)

    Hiendlmeier, G.; Schmeller, H.


    The German Telecommunications Satellite (DFS) Program is to provide telecommunications service for high data rate transmission of text and video data to the Federal Republic of Germany within the 11-14 GHz and 20-30 GHz bands. The space segment of this program is composed of three satellites, DFS-1, DFS-2, and DFS-3, which will be located at 23.5 degrees E longitude of the geostationary orbit. The DFS will be launched from the Center Spatial Guyanis in French Giana on an Ariane launch vehicle. The mission follows the typical injection sequence: parking orbit, transfer orbit, and earth orbit. Attitude maneuvers will be performed to orient the spacecraft prior to Apogee Kick Motor (AKM) firing. After AKM firing, drift phase orbital and attitude maneuvers will be performed to place the spacecraft in its final geostationary position. The Deep Space Network (DSN) will support the transfer and drift orbit mission phases. Information is presented in tabular form for the following areas: DSN support, compatibility testing, frequency assignments, telemetry, command, and tracking support responsibilities.

  5. Solar power satellite cost estimate

    Harron, R. J.; Wadle, R. C.


    The solar power configuration costed is the 5 GW silicon solar cell reference system. The subsystems identified by work breakdown structure elements to the lowest level for which cost information was generated. This breakdown divides into five sections: the satellite, construction, transportation, the ground receiving station and maintenance. For each work breakdown structure element, a definition, design description and cost estimate were included. An effort was made to include for each element a reference that more thoroughly describes the element and the method of costing used. All costs are in 1977 dollars.

  6. NOAA's future GOES satellite program

    Howard, Edward; Heymann, Roger; Dittberner, Gerald J.; Kirkner, Steven


    Future weather satellites for NOAA at geosynchronous orbit may be smaller, less costly, and developed by a different process than is currently done. This path is sometimes called the 'smaller, cheaper and faster' process being pursued by NASA. We believe in the future there will be less money, a focus on using the right technology and the desire to get the most value for the resources invested in space missions. In this paper we give an update on our progress to define future GOES. It will include our efforts to trade on user requirement early, to use evolutionary technology, and to consider new cost reduction and program management techniques.

  7. Satellite spectra of heliumlike nickel

    Spectra of heliumlike nickel, NiXXVII, have been observed from Tokamak Fusion Test Reactor (TFTR) plasmas with a high resolution crystal spectrometer. The experimental arrangement permits simultaneous observation of the heliumlike resonance line, the intercombination and forbidden lines, and all the associated satellites due to transitions 1s2nl - 1s2l'nl'' with N ≥ 2. Relative wavelengths and line intensities can thus be determined very accurately. The observed spectral data are in good agreement with results from the present Hartree-Fock-Slater atomic model calculations and predictions from the Z-expansion method

  8. Bringing satellite winds to hub-height

    Badger, Merete; Pena Diaz, Alfredo; Bredesen, Rolv Erlend; Berge, Erik; Hahmann, Andrea N.; Badger, Jake; Karagali, Ioanna; Hasager, Charlotte Bay; Mikkelsen, Torben


    Satellite observations of the ocean surface can provide detailed information about the spatial wind variability over large areas. This is very valuable for the mapping of wind resources offshore where other measurements are costly and sparse. Satellite sensors operating at microwave frequencies...... measure the amount of radar backscatter from the sea surface, which is a function of the instant wind speed, wind direction, and satellite viewing geometry. A major limitation related to wind retrievals from satellite observations is that existing empirical model functions relate the radar backscatter to...... wind speed at the height 10 m only. The extrapolation of satellite wind fields to higher heights, which are more relevant for wind energy, remains a challenge which cannot be addressed by means of satellite data alone. As part of the EU-NORSEWInD project (2008-12), a hybrid method has been developed...

  9. SATELLITE FORMATION from ancient massive rings

    Crida, Aurélien; Charnoz, Sébastien


    When a planetary tidal disk - like Saturn's rings - spreads beyond the Roche radius (inside which planetary tides prevent aggregation), satellites form and migrate away. Here, we show that most regular satellites in the solar system probably formed in this way. According to our analytical model, when the spreading is slow, a retinue of satellites appear with masses increasing with distance to the Roche radius, in excellent agreement with Saturn's, Uranus', and Neptune's satellite systems. This suggests that Uranus and Neptune used to have massive rings that disappeared to give birth to most of their regular satellites. In contrast, when the spreading is fast, only one large satellite forms, as was the case for Pluto and Earth. This conceptually bridges the gap between terrestrial and giant planet systems. (Ref: Crida & Charnoz 2012, Science, 338, 1196-1199)

  10. Kagawa Satellite “STARS” in Shikoku

    Nohmi, Masahiro; Yamamoto, Takeshi; Andatsu, Akira; Takagi, Yohei; Nishikawa, Yusuke; Kaneko, Takashi; Kunitom, Daisuke

    The Space Tethered Autonomous Robotic Satellite (STARS) is being developed in Kagawa University, and it will be launched by the H-IIA rocket by Japan Aerospace Exploration Agency (JAXA) in summer 2008. STARS is the first satellite developed in Shikoku, and its specific characteristics are: (i) mother and daughter satellites, which have basic satellite system respectively, and those are launched at the same time; (ii) large space system more than 5m by extending tether; (iii) robotic system, the daughter satellite controls its arm link and the mother satellite controls tether extension. Development of STARS in Kagawa University demonstrates space technology in local community, which has been considered to be a national project. Also, it promotes popularization, enlightenment, and understanding of space technology in local area of the Kagawa prefecture and around it.

  11. An introduction to optimal satellite range scheduling

    Vázquez Álvarez, Antonio José


    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, ...

  12. The lopsided distribution of satellite galaxies

    Libeskind, Noam I; Tempel, Elmo; Ibata, Rodrigo


    The distribution of smaller satellite galaxies around large central galaxies has attracted attention because peculiar spatial and kinematic configurations have been detected in some systems. A particularly striking example of such behavior is seen in the satellite system of the Andromeda galaxy, where around 80\\% are on the nearside of that galaxy, facing the Milky Way. Motivated by this departure from anisotropy, we examined the spatial distribution of satellites around pairs of galaxies in the SDSS. By stacking tens of thousands of satellites around galaxy pairs we found that satellites tend to bulge towards the other central galaxy, preferably occupying the space between the pair, rather than being spherically or axis-symmetrically distributed around each host. The bulging is a function of the opening angle examined and is fairly strong -- there are up to $\\sim$10\\% more satellites in the space between the pair, than expected from uniform. Consequently, it is a statistically very strong signal, being incon...

  13. Satellite information for wind energy applications

    Nielsen, M.; Astrup, Poul; Hasager, Charlotte Bay; R. J. Barthelmie; S. C. Pryor


    An introduction to satellite information relevant for wind energy applications is given. It includes digital elevation model (DEM) data based on satellite observations. The Shuttle Radar Topography Mission (SRTM) is useful for regional scale wind resourcestudies. Comparison results from complex terrain in Spain and flat terrain in Denmark are found to be acceptable for both sites. Also land cover type information can be retrieved from satellite observations. Land cover type maps have to be co...

  14. Tethered satellite system dynamics and control

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


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

  15. SaVi: satellite constellation visualization

    Wood, Lloyd


    SaVi, a program for visualizing satellite orbits, movement, and coverage, is maintained at the University of Surrey. This tool has been used for research in academic papers, and by industry companies designing and intending to deploy satellite constellations. It has also proven useful for demonstrating aspects of satellite constellations and their geometry, coverage and movement for educational and teaching purposes. SaVi is introduced and described briefly here.

  16. MICROSAT: A New, Small Satellite Bus Concept

    Duncan, Courtney


    The Radio Amateur Satellite Corporation of North America (AMSAT-NA) is pioneering a new, small satellite bus concept known as "Microsat." The product is roughly a nine inch cube, exclusive of antennas, with five sub-assemblies. Four are standard: radio transmitter(s), radio receiver(s), power system, and onboard computer. The fifth module is reserved for payload or special application hardware. Design goals dictate that the cost of the satellites and the cost and complexity of ground terminal...

  17. Global navigation satellite systems and their applications

    Madry, Scott


    Dr. Madry, one of the world's leading experts in the field, provides in a condensed form a quick yet comprehensive overview of satellite navigation. This book concisely addresses the latest technology, the applications, the regulatory issues, and the strategic implications of satellite navigation systems. This assesses the strengths and weaknesses of satellite navigation networks and review of all the various national systems now being deployed and the motivation behind the proliferation of these systems.


    We conducted a satellite search around the dwarf planet 1 Ceres using Hubble Space Telescope and ground-based Palomar data. No candidate objects were found orbiting Ceres in its entire stability region down to ∼500 km from the surface of Ceres. Assuming a satellite would have the same albedo as Ceres, which has a visual geometric albedo of 0.07-0.10, our detection limit is sensitive to satellites larger than 1-2 km in diameter.

  19. Satellite Sanitary Systems in Kampala, Uganda

    Letema, S.; Van Vliet, B.; Van Lier, J.B.


    Satellite sewage collection and treatment systems have been independently developed and managed in East African cities outside the centrally planned and sewered areas. A satellite approach is a promising provisioning option parallel to public sewerage for middle- and high-income residential areas, endowed institutions, and government facilities. Although the studied satellite systems offer localized solutions that fit the situation of Kampala, better treatment and management arrangements are ...

  20. Identifying true satellites of the Magellanic Clouds

    Sales, Laura V.; Navarro, Julio F.; Kallivayalil, Nitya; Frenk, Carlos S.


    The hierarchical nature of LCDM suggests that the Magellanic Clouds must have been surrounded by a number of satellites before their infall into the Milky Way. Many of those satellites should still be in close proximity to the Clouds, but some could have dispersed ahead/behind the Clouds along their Galactic orbit. Either way, prior association with the Clouds results in strong restrictions on the present-day positions and velocities of candidate Magellanic satellites: they must lie close to ...

  1. Alignments between galaxies, satellite systems and haloes

    Shao, Shi; Cautun, Marius; Frenk, Carlos S.; Gao, Liang; Crain, Robert A.; Schaller, Matthieu; Schaye, Joop; Theuns, Tom


    The spatial distribution of the satellite populations of the Milky Way and Andromeda are puzzling in that they are nearly perpendicular to the disks of their central galaxies. To understand the origin of such configurations we study the alignment of the central galaxy, satellite system and dark matter halo in the largest of the "Evolution and Assembly of GaLaxies and their Environments" (EAGLE) simulation. We find that centrals and their satellite systems tend to be well aligned with their ha...

  2. Pakistan National Student Satellite Program (PNSSP)

    Alvi, Bilal Ahmad


    Micro-satellite development at University environment provides hands-on experience of building a satellite from design through launch and orbit operations for students in a cost effective way. Since multi-disciplinary efforts are required for satellite program are normally available in Universities therefore this kind of projects coupled with team building would provide valuable contribution to aerospace field. It would not only involve traini...

  3. Satellite radiation observations and climate theory

    Ohring, G.; Gruber, A.


    The representative applications of satellite observations of the earth radiation budget in climate studies are discussed. Consideration is given to the use of satellite observational data for validating numerical estimates of the sensitivity of longwave radiation, surface temperature, and cloud amount to changes in the radiation budget. Particular emphasis is given to the application of satellite observations to the validation of temperature estimates obtained from the NOAA Seasonal Hemispheric Zonal Average Model (SZHAM).

  4. Field Command of a Tactical Satellite System

    Turner, Ron; Hopkins, Stephen


    One way to ensure tactical satellite systems remain fully responsive to a field commander's needs would be to place all command and control aspects of the system under direct field control. This paper presents the results of a study to evaluate the feasibility of field command of a notional tactical imaging satellite system. The study indicates that such a system is feasible. A satellite constellation can be designed to provide the field commander with significant, timely, tactical data. The ...

  5. Satellite Remote Sensing in Seismology. A Review

    Andrew A. Tronin


    A wide range of satellite methods is applied now in seismology. The first applications of satellite data for earthquake exploration were initiated in the ‘70s, when active faults were mapped on satellite images. It was a pure and simple extrapolation of airphoto geological interpretation methods into space. The modern embodiment of this method is alignment analysis. Time series of alignments on the Earth's surface are investigated before and after the earthquake. A further application of sate...

  6. Towards generic satellite payloads: software radio

    Morlet, Catherine; Boucheret, Marie-Laure; Calmettes, Vincent; Paillassa, Béatrice; Pérennou, Tanguy


    Satellite payloads are becoming much more complex with the evolution towards multimedia applications. Moreover satellite lifetime increases while standard and services evolve faster, necessitating a hardware platform that can evolves for not developing new systems on each change. The same problem occurs in terrestrial systems like mobile networks and a foreseen solution is the software defined radio technology. In this paper we describe a way of introducing this concept at satellite level to ...

  7. Regulation of satellite cell function in sarcopenia

    Alway, Stephen E.; Myers, Matthew J.; Mohamed, Junaith S.


    The mechanisms contributing to sarcopenia include reduced satellite cell (myogenic stem cell) function that is impacted by the environment (niche) of these cells. Satellite cell function is affected by oxidative stress, which is elevated in aged muscles, and this along with changes in largely unknown systemic factors, likely contribute to the manner in which satellite cells respond to stressors such as exercise, disuse or rehabilitation in sarcopenic muscles. Nutritional intervention provides...

  8. Regulation of Satellite Cell Function in Sarcopenia

    Alway, Stephen E.; Myers, Matthew J.; Mohamed, Junaith S.


    The mechanisms contributing to sarcopenia include reduced satellite cell (myogenic stem cell) function that is impacted by the environment (niche) of these cells. Satellite cell function is affected by oxidative stress, which is elevated in aged muscles, and this along with changes in largely unknown systemic factors, likely contribute to the manner in which satellite cells respond to stressors such as exercise, disuse, or rehabilitation in sarcopenic muscles. Nutritional intervention provide...

  9. Some Mathematical Problems of Satellite Networks

    Lo, Martin


    Economic forces and technology development have made low-earth-orbit satellite constellations extremely attractive to the emergent personal communications industry. These constellations range from 2 to nearly 1000 satellites. Even though none of the constellations are as yet completely deployed, design on second generation constellations have already begun. The satellite coverage and network links provide some interesting mathematical problems. We examine some of the geometric and combinatorial problems associated with these networks.

  10. Star Tracker Cost Reduction for Small Satellites

    Delabie, Tjorven; DE SCHUTTER, JORIS; Vandenbussche, Bart


    In recent years, the great potential of small satellites has become ever clearer and small satellites are selected to perform increasingly complex missions. With this rise in mission complexity, the requirements on the Attitude Determination and Control System of the satellite increase as well. Of all the attitude determination sensors, the star tracker is by far the most accurate one. The accuracy of this sensor is in the order of arc seconds. The disadvantages of this sensor are that it...

  11. Formation and evolution of Pluto's small satellites

    Walsh, Kevin J.; Levison, Harold F.


    Pluto's system of 5 known satellites are in a puzzling orbital configuration. Each of the four small satellites are on low-eccentricity and low-inclination orbits situated near a mean motion resonance with the largest satellite Charon. The Pluto-Charon binary likely formed as a result of a giant impact and so the simplest explanation for the small satellites is that they accreted from debris of that collision. The Pluto-Charon binary has evolved outward since its formation due to tidal forces...

  12. Blossom Point Satellite Tracking and Command Station

    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...

  13. Commissioning of the Tevatron Satellite Refrigeration system

    This chapter describes the cooling of the new Fermilab 6 km circumference superconducting proton accelerator by a 5000 L/h central helium liquefier (CHL) coupled with 24 satellite refrigerators (966W each). The Tevatron Satellite Refrigeration system includes a liquid helium/liquid nitrogen transfer line made up of twenty six-250 m long sections. Topics considered include transfer line operation, compressor system operation, satellite refrigeration operational experience, contamination, expansion engine efficiency, control loop stability, pressure drop, the magnet system operational experience, magnet cooldown, vacuum deficiencies, and magnet excitation. It is concluded that the satellite refrigerator concept has proven to be a reliable design for the Tevatron

  14. TUBSAT-1, satellite technology for educational purposes

    Ginati, A.


    TUBSAT-1 (Technical University of Berlin Satellite) is an experimental low-cost satellite within the NASA Get Away Special (GAS) program. This project is being financed by the German BMFT (Federal Ministry for Research and Technology), mainly for student education. The dimensions and weight are determined by GAS requirements and the satellite will be ejected from the space shuttle into an approximately 300-km circular orbit. It is a sun/star oriented satellite with an additional spin stabilization mode. The first planned payload is to be used for observing flight paths of migratory birds from northern Europe to southern Africa and back.

  15. International Satellite Cloud Climatology Project (ISCCP)

    National Aeronautics and Space Administration — International Satellite Cloud Climatology Project (ISCCP) focuses on the distribution and variation of cloud radiative properties to improve the understanding of...

  16. Ravens satellite mission concept study

    Donovan, Eric F


    The concept for Ravens satellite mission was proposed in response to a CSA AO for potential Canadian mission contributions to the International Living With a Star (ILWS) program. Ravens was conceived of to fill an important gap in the ILWS program: global imaging. Ravens will build on the heritage of world-class global imaging carried out in Canada. It would do much more than provide global observations to complete the system level capabilities of ILWS. Ravens would be comprised of two satellites on elliptical polar orbits, relatively phased on those orbits to provide the first-ever continuous (ie., 24 hours per day 7 days per week) global imaging of the northern hemisphere auroral and polar cap regions. This would provide the first-ever unbroken sequences of global images of the auroral response during long duration geomagnetic processes like storms and steady magnetospheric convection events. Ravens could track the spatio-temporal evolution of the global electron and proton auroral distribution, and would o...

  17. Automated satellite telemetry processing system

    Parunakian, David; Kalegaev, Vladimir; Barinova, Vera

    In this paper we describe the design and important implementation details of the new automated system for processing satellite telemetry developedat Skobeltsyn Institute of Nuclear Physics of Moscow State University (SINP MSU) . We discuss the most common tasks and pitfall for such systems built around data stream from a single spacecraft or a single instrument, and suggest a solution that allows to quickly develop telemetry processing modules and to integrate them with an existing polling mechanism, support infrastructure and data storage in Oracle or MySQL database systems. We also demonstrate the benefits of this approach using modules for processing three different spacecraft data streams: Coronas-Photon (2009-003A), Tatiana-2 (2009-049D) and Meteor-M no.1 (2009-049A). The data format and protocols used by each of these spacecraft have distinct peculiarities, which nevertheless did not pose a problem for integrating their modules into the main system. Remote access via web interface to Oracle databases and sophisticated visualization tools create a possibility of efficient scientific exploitation of satellite data. Such a system is already deployed at the web portal of the Space Monitoring Data Center (SMDC) of SINP MSU (

  18. The Canadian mobile satellite program

    Boudreau, P. M.; Breithaupt, R. W.; McNally, J. L.

    The progressions and selection of design features for the Canadian segment of a mobile satellite (MSAT) communications system are traced. The feasibility study for a satellite-based public and government mobile communications service to underserved areas was carried out between 1980-82. The results covered the market demand, commercial viability, user cost-benefit, and spacecraft concepts. A subsequent 2 yr study was initiated to proceed with project definition. A market of 1.1 million users was identified in all of Canada, with MSAT replacing other systems for 50 percent of the market. Operations would be in the 806-890 MHz range. Traffic will be routed through gateway links functioning in the 8/7 GHz SHF band while the mobile units will be connected through an 821-825 MHz up link and an 866-870 MH downlink. New technologies will be needed for a central control station, the gateway stations, and the base stations for the mobile radio service, the mobile user terminals, and data collection platforms.

  19. Interim Service ISDN Satellite (ISIS) simulator development for advanced satellite designs and experiments

    Pepin, Gerard R.


    The simulation development associated with the network models of both the Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) and the Full Service ISDN Satellite (FSIS) architectures is documented. The ISIS Network Model design represents satellite systems like the Advanced Communications Technology Satellite (ACTS) orbiting switch. The FSIS architecture, the ultimate aim of this element of the Satellite Communications Applications Research (SCAR) Program, moves all control and switching functions on-board the next generation ISDN communications satellite. The technical and operational parameters for the advanced ISDN communications satellite design will be obtained from the simulation of ISIS and FSIS engineering software models for their major subsystems. Discrete event simulation experiments will be performed with these models using various traffic scenarios, design parameters, and operational procedures. The data from these simulations will be used to determine the engineering parameters for the advanced ISDN communications satellite.

  20. Doppler factors in satellite-to-satellite tracking. [with relativistic effects

    Marini, J. W.


    The Doppler factors occurring in range rate satellite-to-satellite tracking measurements are derived with special relativistic effects included. The error resulting from the use of simplified expressions for these factors is discussed.

  1. Economics of satellite communications systems

    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

  2. Satellite orbit determination using satellite gravity gradiometry observations in GOCE mission perspective

    Bobojć, A.; Drożyner, A.


    Between the years 2004 and 2005 the launch of the first gradiometric satellite is planned. This satellite will be an important element of the Gravity Field and Steady ? State Ocean Circulation Explorer Mission (GOCE). This mission is one of the reasons for performing the simulation research of the Satellite Gravity Gradiometry. Our work contains the theory description and simulation results of the satellite orbit determination using the gravity tensor observations. In the process of the satel...

  3. Satellite orbit determination using satellite gravity gradiometry observations in GOCE mission perspective

    Bobojć, A.; Drożyner, A.


    Between the years 2004 and 2005 the launch of the first gradiometric satellite is planned. This satellite will be an important element of the Gravity Field and Steady – State Ocean Circulation Explorer Mission (GOCE). This mission is one of the reasons for performing the simulation research of the Satellite Gravity Gradiometry. Our work contains the theory description and simulation results of the satellite orbit determination using the gravity tensor observations. In ...

  4. China Land Observation Satellite Third User Conference Promotes The Applications Of Domestic Satellite Data

    Zong He


    @@ China Land Observation Satellite Third User Conference with the theme of "Strengthening cooperation,enlarging sharing and promoting the application of domestic satellite data" was held on July 16,2009 in Beijing. The conference was hosted by China Centre for Resources Satellite Data and Applications(CRESDA),a subsidiary of China Aerospace Science and Technology Corporation (CASC).

  5. Determination of the number of navigation satellites within satellite acquisition range

    The problem of determination of the number of navigation satellites within acquisition range with regard to antenna systems configuration and stochastic land remote sensing satellite maneuvers is the subject considered in the paper. Distribution function and density function of the number of navigation satellites within acquisition range are obtained

  6. History of Satellite TV Broadcasting and Satellite Broadcasting Market in Turkey

    Mihalis KUYUCU


    The present study analyses the satellite broadcasting that is the first important development that emerged as a result of digitalization in communication technologies and its reflections in Turkey. As the first milestone in the globalization of television broadcasting, satellite broadcasting provided substantial contribution towards the development of the media. Satellite bro adcasting both increased the broadcasting qualit...

  7. Synchronized Position Hold, Engage, Reorient, Experimental Satellites

    Miller, David W.; Wilson, Edward; How, Jonathan; Sanenz-Otero, Alvar; Chamitoff, Gregory


    Synchronized Position Hold, Engage, Reorient, Experimental Satellites (SPHERES) are bowling-ball sized spherical satellites. They will be used inside the space station to test a set of well-defined instructions for spacecraft performing autonomous rendezvous and docking maneuvers. Three free-flying spheres will fly within the cabin of the station, performing flight formations. Each satellite is self-contained with power, propulsion, computers and navigation equipment. The results are important for satellite servicing, vehicle assembly and formation flying spacecraft configurations. SPHERES is a testbed for formation flying by satellites, the theories and calculations that coordinate the motion of multiple bodies maneuvering in microgravity. To achieve this inside the ISS cabin, bowling-ball-sized spheres perform various maneuvers (or protocols), with one to three spheres operating simultaneously . The Synchronized Position Hold, Engage, Reorient, Experimental Satellites (SPHERES) experiment will test relative attitude control and station-keeping between satellites, re-targeting and image plane filling maneuvers, collision avoidance and fuel balancing algorithms, and an array of geometry estimators used in various missions. SPHERES consists of three self-contained satellites, which are 18 sided polyhedrons that are 0.2 meter in diameter and weigh 3.5 kilograms. Each satellite contains an internal propulsion system, power, avionics, software, communications, and metrology subsystems. The propulsion system uses CO2, which is expelled through the thrusters. SPHERES satellites are powered by AA batteries. The metrology subsystem provides real-time position and attitude information. To simulate ground station-keeping, a laptop will be used to transmit navigational data and formation flying algorithms. Once these data are uploaded, the satellites will perform autonomously and hold the formation until a new command is given.


    Francisco Sacristán Romero


    Full Text Available SUMMARY This article comprises of an investigation that approaches a so complex subject and in process as the trajectory, from its birth like project, of the Spanish satellite of communications HISPASAT. HISPASAT supposes to enter in the more fascinating world of the technologies out poste with the risk of believing have approval part of the possibilities that it offers, when in fact not we have begun the study of a plan in transition. The investigators that come behind us will extend and enrich the information on the great legacy which, from already, are leaving net Spanish technical and human resources. HISPASAT offers the possibility that the languages and the cultures of our country transfer the international borders and they enter in corners of Europe, America and Africa where it had a superficial knowledge of our customs, wealthy and stronger traditions.

  9. Satellite-Derived Management Zones

    Lepoutre, Damien; Layrol, Laurent


    The term "satellite-derived management zones" (SAMZ) denotes agricultural management zones that are subdivisions of large fields and that are derived from images of the fields acquired by instruments aboard Earth-orbiting satellites during approximately the past 15 years. "SAMZ" also denotes the methodology and the software that implements the methodology for creating such zones. The SAMZ approach is one of several products of continuing efforts to realize a concept of precision agriculture, which involves optimal variations in seeding, in application of chemicals, and in irrigation, plus decisions to farm or not to farm certain portions of fields, all in an effort to maximize profitability in view of spatial and temporal variations in the growth and health of crops, and in the chemical and physical conditions of soils. As used here, "management zone" signifies, more precisely, a subdivision of a field within which the crop-production behavior is regarded as homogeneous. From the perspective of precision agriculture, management zones are the smallest subdivisions between which the seeding, application of chemicals, and other management parameters are to be varied. In the SAMZ approach, the main sources of data are the archives of satellite imagery that have been collected over the years for diverse purposes. One of the main advantages afforded by the SAMZ approach is that the data in these archives can be reused for purposes of precision agriculture at low cost. De facto, these archives contain information on all sources of variability within a field, including weather, crop types, crop management, soil types, and water drainage patterns. The SAMZ methodology involves the establishment of a Web-based interface based on an algorithm that generates management zones automatically and quickly from archival satellite image data in response to requests from farmers. A farmer can make a request by either uploading data describing a field boundary to the Web site or else

  10. Astrophysics with small satellites in Scandinavia

    Lund, Niels


    The small-satellites activities in the Scandinavian countries are briefly surveyed with emphasis on astrophysics research. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.......The small-satellites activities in the Scandinavian countries are briefly surveyed with emphasis on astrophysics research. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved....

  11. Satellite Remote Sensing in Offshore Wind Energy

    Hasager, Charlotte Bay; Badger, Merete; Astrup, Poul;


    Satellite remote sensing of ocean surface winds are presented with focus on wind energy applications. The history on operational and research-based satellite ocean wind mapping is briefly described for passive microwave, scatterometer and synthetic aperture radar (SAR). Currently 6 GW installed...


    Stojce Ilcev


    Full Text Available Abstract. This paper introduces development and implementation of new Local Satellite AugmentationSystem as an integration component of the Regional Satellite Augmentation System (RSAS employingcurrent and new Satellite Communications, Navigation and Surveillance (CNS for improvement of the AirTraffic Control (ATC and Air Traffic Management (ATM and for enhancement safety systems includingtransport security and control of flights in all stages, airport approaching, landing, departures and allmovements over airport surface areas. The current first generation of the Global Navigation Satellite SystemGNSS-1 applications are represented by fundamental military solutions for Position, Velocity and Time ofthe satellite navigation and determination systems such as the US GPS and Russian GLONASS (Former-USSR requirements, respectively. The establishment of Aeronautical CNS is also discussed as a part ofGlobal Satellite Augmentation Systems of GPS and GLONASS systems integrated with existing and futureRSAS and LSAS in airports areas. Specific influence and factors related to the Comparison of the Currentand New Aeronautical CNS System including the Integration of RSAS and GNSS solutions are discussedand packet of facts is determined to maximize the new satellite Automatic Dependent Surveillance System(ADSS and Special Effects of the RSAS Networks. The possible future integration of RSAS and GNSS andthe common proposal of the satellite Surface Movement Guidance and Control are presented in thechangeless ways as of importance for future enfacements of ATC and ATM for any hypothetical airportinfrastructure.Keywords: ADSS, ATC, ATM, CNS, GSAS, LRAS, RSAS, SMGC, Special Effects of RSAS.

  13. Astrophysics with small satellites in Scandinavia

    Lund, Niels

    The small-satellites activities in the Scandinavian countries are briefly surveyed with emphasis on astrophysics research. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.......The small-satellites activities in the Scandinavian countries are briefly surveyed with emphasis on astrophysics research. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved....

  14. RFP for CNES micro satellite program

    Jørgensen, John Leif; Jørgensen, Finn E; Betto, Maurizio;


    This document descibes the ASC STAR TRACKER (performance, functionality, requirements etc.) to the Centre National d'Etudes Spatiales (CNES) for their micro Satellites.......This document descibes the ASC STAR TRACKER (performance, functionality, requirements etc.) to the Centre National d'Etudes Spatiales (CNES) for their micro Satellites....

  15. Interim Service ISDN Satellite (ISIS) hardware experiment design for advanced ISDN satellite design and experiments

    Pepin, Gerard R.


    The Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) Hardware Experiment Design for Advanced Satellite Designs describes the design of the ISDN Satellite Terminal Adapter (ISTA) capable of translating ISDN protocol traffic into time division multiple access (TDMA) signals for use by a communications satellite. The ISTA connects the Type 1 Network Termination (NT1) via the U-interface on the line termination side of the CPE to the V.35 interface for satellite uplink. The same ISTA converts in the opposite direction the V.35 to U-interface data with a simple switch setting.

  16. Future Satellite Gravimetry and Earth Dynamics

    Flury, Jakob


    Currently, a first generation of dedicated satellite missions for the precise mapping of the Earth’s gravity field is in orbit (CHAMP, GRACE, and soon GOCE). The gravity data from these satellite missions provide us with very new information on the dynamics of planet Earth. In particular, on the mass distribution in the Earth’s interior, the entire water cycle (ocean circulation, ice mass balance, continental water masses, and atmosphere), and on changes in the mass distribution. The results are fascinating, but still rough with respect to spatial and temporal resolution. Technical progress in satellite-to-satellite tracking and in gravity gradiometry will allow more detailed results in the future. In this special issue, Earth scientists develop visions of future applications based on follow-on high-precision satellite gravimetry missions.

  17. Capture of Irregular Satellites at Jupiter

    Nesvorny, D; Deienno, R


    The irregular satellites of outer planets are thought to have been captured from heliocentric orbits. The exact nature of the capture process, however, remains uncertain. We examine the possibility that irregular satellites were captured from the planetesimal disk during the early Solar System instability when encounters between the outer planets occurred (Nesvorny, Vokrouhlicky & Morbidelli 2007, AJ 133; hereafter NVM07). NVM07 already showed that the irregular satellites of Saturn, Uranus and Neptune were plausibly captured during planetary encounters. Here we find that the current instability models present favorable conditions for capture of irregular satellites at Jupiter as well, mainly because Jupiter undergoes a phase of close encounters with an ice giant. We show that the orbital distribution of bodies captured during planetary encounters provides a good match to the observed distribution of irregular satellites at Jupiter. The capture efficiency for each particle in the original transplanetary d...

  18. Air and sea rescue via satellite systems

    Scales, W. C.; Swanson, R.


    Two approaches to a satellite system for air and sea rescue to be put into use by the 1990s, one employing polar-orbiting satellites and the other using fixed geosynchronous satellites over the equator, are discussed. A battery-powered transmitter on a ship or aircraft would be activated in an accident to emit a low-power omnidirectional signal that would be relayed by a satellite to an earth station. The polar-orbiting approach, now being evaluated on a small-scale with the Cospas-Sarsat system, allows complete coverage of the earth, including the poles, and provides a fix on the origin of the distress signals by means of the Doppler shift. A parallel effort for the testing of geostationary satellites to measure system sensitivity to various interference sources, to optimize design, and to measure land and sea performance is reviewed.

  19. High power communication satellites power systems study

    This paper discusses a DOE-funded study to evaluate the commercial attractiveness of high power communication satellites and assesses the attributes of both conventional photovoltaic and reactor power systems. This study brings together a preeminent US Industry/Russian team to cooperate on the role of high power communication satellites in the rapidly expanding communications revolution. These high power satellites play a vital role in assuring availability of universally accessible, wide bandwidth communications, for high definition TV, super computer networks and other services. Satellites are ideally suited to provide the wide bandwidths and data rates required and are unique in the ability to provide services directly to the users. As new or relocated markets arise, satellites offer a flexibility that conventional distribution services cannot match, and it is no longer necessary to be near population centers to take advantage of the telecommunication revolution. The geopolitical implications of these substantially enhanced communications capabilities will be significant

  20. Temperature diagnostics using lithium-like satellites

    A 60-kJ theta-pinch was operated at a filling pressure of 16 mtorr using a gas mixture of 2% neon and 98% helium. The resonance and intercombination lines from Ne IX and the Li-like satellites were observed with a Bragg crystal monochromator. The electron temperature of the plasma was deduced from the intensity ratios of the Ne IX resonance line and the dielectronic satellites using recent theoretical calculations. The temperature values ranged from 210 eV to 340 eV during the time of occurrence of these satellites. The temperature measured at 1.0 μs by laser scattering for a similar plasma condition was in close agreement with that obtained by the resonance line/satellite ratio. This lends confidence to use of the satellite technique for temperature measurements in other plasmas

  1. Regulation of satellite cell function in sarcopenia

    Stephen E Alway


    Full Text Available The mechanisms contributing to sarcopenia include reduced satellite cell (myogenic stem cell function that is impacted by the environment (niche of these cells. Satellite cell function is affected by oxidative stress, which is elevated in aged muscles, and this along with changes in largely unknown systemic factors, likely contribute to the manner in which satellite cells respond to stressors such as exercise, disuse or rehabilitation in sarcopenic muscles. Nutritional intervention provides one therapeutic strategy to improve the satellite cell niche and systemic factors, with the goal of improving satellite cell function in aging muscles. Although many elderly persons consume various nutraceuticals with the hope of improving health, most of these compounds have not been thoroughly tested, and the impacts that they might have on sarcopenia, and satellite cell function are not clear. This review discusses data pertaining to the satellite cell responses and function in aging skeletal muscle, and the impact that three compounds: resveratrol, green tea catechins and β-Hydroxy-β-methylbutyrate have on regulating satellite cell function and therefore contributing to reducing sarcopenia or improving muscle mass after disuse in aging. The data suggest that these nutraceutical compounds improve satellite cell function during rehabilitative loading in animal models of aging after disuse (i.e., muscle regeneration. While these compounds have not been rigorously tested in humans, the data from animal models of aging provide a strong basis for conducting additional focused work to determine if these or other nutraceuticals can offset the muscle losses, or improve regeneration in sarcopenic muscles of older humans via improving satellite cell function.

  2. Regulation of satellite cell function in sarcopenia.

    Alway, Stephen E; Myers, Matthew J; Mohamed, Junaith S


    The mechanisms contributing to sarcopenia include reduced satellite cell (myogenic stem cell) function that is impacted by the environment (niche) of these cells. Satellite cell function is affected by oxidative stress, which is elevated in aged muscles, and this along with changes in largely unknown systemic factors, likely contribute to the manner in which satellite cells respond to stressors such as exercise, disuse, or rehabilitation in sarcopenic muscles. Nutritional intervention provides one therapeutic strategy to improve the satellite cell niche and systemic factors, with the goal of improving satellite cell function in aging muscles. Although many elderly persons consume various nutraceuticals with the hope of improving health, most of these compounds have not been thoroughly tested, and the impacts that they might have on sarcopenia and satellite cell function are not clear. This review discusses data pertaining to the satellite cell responses and function in aging skeletal muscle, and the impact that three compounds: resveratrol, green tea catechins, and β-Hydroxy-β-methylbutyrate have on regulating satellite cell function and therefore contributing to reducing sarcopenia or improving muscle mass after disuse in aging. The data suggest that these nutraceutical compounds improve satellite cell function during rehabilitative loading in animal models of aging after disuse (i.e., muscle regeneration). While these compounds have not been rigorously tested in humans, the data from animal models of aging provide a strong basis for conducting additional focused work to determine if these or other nutraceuticals can offset the muscle losses, or improve regeneration in sarcopenic muscles of older humans via improving satellite cell function. PMID:25295003

  3. Design of the ISAT-1 Satellite Thermal Control System

    Clay, Joseph


    Satellite technology improves the daily lives of almost all human beings. Satellites aid in communication, weather prediction, and global positioning. Other uses for satellites include conducting scientific experiments in micro gravity and space exploration missions. A major constraint placed on all satellites is the cost of launch. With a larger or heavier satellite, a larger more powerful launch vehicle is need. This larger launch vehicle increases the overall satellite cost. The developmen...

  4. Myostatin negatively regulates satellite cell activation and self-renewal

    McCroskery, Seumas; Thomas, Mark; Maxwell, Linda; Sharma, Mridula; Kambadur, Ravi


    Satellite cells are quiescent muscle stem cells that promote postnatal muscle growth and repair. Here we show that myostatin, a TGF-β member, signals satellite cell quiescence and also negatively regulates satellite cell self-renewal. BrdU labeling in vivo revealed that, among the Myostatin-deficient satellite cells, higher numbers of satellite cells are activated as compared with wild type. In contrast, addition of Myostatin to myofiber explant cultures inhibits satellite cell activation. Ce...

  5. Satellite Meteorology Education & Training Resources from COMET

    Abshire, W. E.; Dills, P. N.; Weingroff, M.; Lee, T. F.


    The COMET® Program ( receives funding from NOAA NESDIS as well as EUMETSAT and the Meteorological Service of Canada to support education and training in satellite meteorology. These partnerships enable COMET to create educational materials of global interest on geostationary and polar-orbiting remote sensing platforms. These materials focus on the capabilities and applications of current and next-generation satellites and their relevance to operational forecasters and other user communities. By partnering with experts from the Naval Research Laboratory, NOAA-NESDIS and its Cooperative Institutes, Meteorological Service of Canada, EUMETSAT, and other user communities, COMET stimulates greater use of satellite data observations and products. This presentation provides an overview of COMET's recent satellite education efforts in the area of polar orbiting satellites. COMET has a new module on Suomi NPP, which describes the satellite system and discusses the improvements that it is bringing to forecasting, numerical weather prediction, and environmental monitoring. COMET has also published an updated version of its module on the VIIRS instrument. "Imaging with VIIRS: A Convergence of Technologies and Experience, 2nd Edition" covers the instrument's enhanced capabilities by examining the systems that contributed to its development. Special attention is paid to the Day/Night Visible channel as VIIRS is the first instrument on a civilian satellite to image atmospheric and terrestrial features with and without moonlight. An upcoming module will exclusively focus on nighttime imaging with the VIIRS Day/Night Band (DNB). "Applications of the VIIRS Day-Night Band" will introduce the capabilities of DNB imagery to a wide audience ranging from forecasters and emergency managers to wildfire fighters and oceanographers. DNB products will be compared to traditional satellite products made from infrared data, including the "fog" product. Users will learn how DNB

  6. Satellite antenna management system and method

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


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

  7. Alignments between galaxies, satellite systems and haloes

    Shao, Shi; Frenk, Carlos S; Gao, Liang; Crain, Robert A; Schaller, Matthieu; Schaye, Joop; Theuns, Tom


    The spatial distribution of the satellite populations of the Milky Way and Andromeda are puzzling in that they are nearly perpendicular to the disks of their central galaxies. To understand the origin of such configurations we study the alignment of the central galaxy, satellite system and dark matter halo in the largest of the "Evolution and Assembly of GaLaxies and their Environments" (EAGLE) simulation. We find that centrals and their satellite systems tend to be well aligned with their haloes, with a median misalignment angle of $33^{\\circ}$ in both cases. While the centrals are better aligned with the inner $10$ kpc halo, the satellite systems are better aligned with the entire halo indicating that satellites preferentially trace the outer halo. The central - satellite alignment is weak (median misalignment angle of $52^{\\circ}$) and we find that around $20\\%$ of systems have a misalignment angle larger than $78^{\\circ}$, which is the value for the Milky Way. The central - satellite alignment is a conseq...

  8. Satellite power system salvage and disposal alternatives


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

  9. PRMT7 Preserves Satellite Cell Regenerative Capacity

    Roméo Sébastien Blanc


    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.

  10. Optimization of satellite constellation reconfiguration maneuvers

    Appel, Leonid; Guelman, Moshe; Mishne, David


    Constellation satellites are required to perform orbital transfer maneuvers. Orbital transfer maneuvers, as opposed to orbital correction maneuvers, are seldom performed but require a substantial amount of propellant for each maneuver. The maneuvers are performed in order to obtain the desired constellation configuration that satisfies the coverage requirements. In most cases, the single-satellite position is immaterial; rather the relative position between constellation multiple-satellites is to be controlled. This work deals with the solution to the coupled optimization problem of multiple-satellite orbital transfer. The studied problem involves a coupled formulation of the terminal conditions of the satellites. The solution was achieved using functional optimization techniques by a combined algorithm. The combined algorithm is based on the First Order Gradient and Neighboring-Extremals Algorithms. An orbital transfer optimization tool was developed. This software has the ability to consider multiple satellites with coupled terminal conditions. A solution to the multiple-satellite orbital transfer optimization problem is presented. A comparison of this solution to the uncoupled case is presented in order to review the benefits of using this approach. It is concluded that the coupled transfer maneuver solution approach is more computationally efficient and more accurate. Numerical solutions for a number of representative cases are presented.