Overview of the Anik C satellites and services

Science.gov (United States)

Smart, F. H.

An overview of the important technical characteristics of the Anik C series of Canadian communications satellites is presented. The system was launched as part of the Telesat Communications payload of the Space Shuttle in 1982. Among the services the system will in the near future provide are: a 27 MHz channel bandwidth television service for pay-TV distribution in Canada; two TV channels for hockey broadcasts and a transportable TV system; a heavy-voice route telephone service for five major Canadian cities; and a telephone system for business voice and data communications. Services anticipated for Anik-C satellites later in the decade include a Single Channel Per Carrier (SCPC) voice and data communications system for British Columbia and the Maritime Provinces, and a direct-to-home broadcast service to be sold to television markets in the United States.

Land mobile satellite services in Europe

Science.gov (United States)

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

The demand for land-mobile communications on a Europe-wide basis is an important and pressing problem. The pan-European cellular network now in the planning stage will be slow in coming and it will have its limitations. A regional satellite system for Europe to complement the cellular network is the only practical way to satisfy a specialised market that encompasses a population of several hundred thousand mobiles, including road vehicles, merchant shipping, fishing boats, and trains. The deployment of a regional system would take place in a number of phases, the first being based on a simple payload embarked on a host satellite belonging to a European organisation. Further phases will involve the development of more advanced payloads on dedicated satellites. For the long-term future, the use of satellites in highly inclined orbits is being considered as a means of improving their visibility and hence the service quality.

Definition of technology development missions for early space station satellite servicing, volume 1

Science.gov (United States)

1983-01-01

The testbed role of an early manned space station in the context of a satellite servicing evolutionary development and flight demonstration technology plan which results in a satellite servicing operational capability is defined. A satellite servicing technology development mission (a set of missions) to be performed on an early manned space station is conceptually defined.

47 CFR 25.213 - Inter-Service coordination requirements for the 1.6/2.4 GHz mobile-satellite service.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Inter-Service coordination requirements for the 1.6/2.4 GHz mobile-satellite service. 25.213 Section 25.213 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.213 Inter...

Servicing communication satellites in geostationary orbit

Science.gov (United States)

Russell, Paul K.; Price, Kent M.

1990-01-01

The econmic benefits of a LEO space station are quantified by identifying alternative operating scenarios utilizing the space station's transportation facilities and assembly and repair facilities. Particular consideration is given to the analysis of the impact of on-orbit assembly and servicing on a typical communications satellite is analyzed. The results of this study show that on-orbit servicing can increase the internal rate of return by as much as 30 percent.

47 CFR 25.148 - Licensing provisions for the Direct Broadcast Satellite Service.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Licensing provisions for the Direct Broadcast Satellite Service. 25.148 Section 25.148 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses Space Stations § 25.148...

47 CFR 25.211 - Analog video transmissions in the Fixed-Satellite Services.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Analog video transmissions in the Fixed-Satellite Services. 25.211 Section 25.211 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.211 Analog video transmissions...

Definition of technology development missions for early Space Station satellite servicing. Volume 1: Executive summary

Science.gov (United States)

1984-01-01

The Executive Summary volume 1, includes an overview of both phases of the Definition of Technology Development Missions for Early Space Station Satellite Servicing. The primary purpose of Phase 1 of the Marshall Space Flight Center (MSFC) Satellite Servicing Phase 1 study was to establish requirements for demonstrating the capability of performing satellite servicing activities on a permanently manned Space Station in the early 1990s. The scope of Phase 1 included TDM definition, outlining of servicing objectives, derivation of initial Space Station servicing support requirements, and generation of the associated programmatic schedules and cost. The purpose of phase 2 of the satellite servicing study was to expand and refine the overall understanding of how best to use the manned space station as a test bed for demonstration of satellite servicing capabilities.

Customer premise service study for 30/20 GHz satellite system

Science.gov (United States)

Milton, R. T.; Ross, D. P.; Harcar, A. R.; Freedenberg, P.; Schoen, D.

1983-01-01

Satellite systems in which the space segment operates in the 30/20 GHz frequency band are defined and compared as to their potential for providing various types of communications services to customer premises and the economic and technical feasibility of doing so. Technical tasks performed include: market postulation, definition of the ground segment, definition of the space segment, definition of the integrated satellite system, service costs for satellite systems, sensitivity analysis, and critical technology. Based on an analysis of market data, a sufficiently large market for services is projected so as to make the system economically viable. A large market, and hence a high capacity satellite system, is found to be necessary to minimize service costs, i.e., economy of scale is found to hold. The wide bandwidth expected to be available in the 30/20 GHz band, along with frequency reuse which further increases the effective system bandwidth, makes possible the high capacity system. Extensive ground networking is required in most systems to both connect users into the system and to interconnect Earth stations to provide spatial diversity. Earth station spatial diversity is found to be a cost effective means of compensating the large fading encountered in the 30/20 GHz operating band.

Emerging markets for satellite data communications in the public service

Science.gov (United States)

Potter, J. G.

1978-01-01

The paper discusses some of the current and potential markets for satellite data communications as projected by the Public Service Satellite Consortium (PSSC). Organizations in the public service sector are divided into three categories, depending on their expected benefits and organizational changes due to increased satellite telecommunications use: A - modest institutional adjustments are necessary and significant productivity gains are likely; B - institutional requirements picture is promising, but more information is needed to assess benefits and risk; and C - major institutional adjustments are needed, risks are high but possible benefits are high. These criteria are applied to the U.S. health care system, continuing education, equipment maintenance, libraries, environmental monitoring, and other potential markets. The potential revenues are seen to be significant, but what is needed is a cooperative effort by common carriers and major public service institutions to aggregate the market.

National Oceanic and Atmospheric Administration: National Weather Service Modernization and Weather Satellite Program

National Research Council Canada - National Science Library

Willemssen, Joel

2000-01-01

...). At your request, we will discuss the status of the National Weather Service (NWS) systems modernization and the National Environmental Satellite, Data, and Information Service's Geostationary Operational Environmental Satellite (GOES) program...

LEOPACK The integrated services communications system based on LEO satellites

Science.gov (United States)

Negoda, A.; Bunin, S.; Bushuev, E.; Dranovsky, V.

LEOPACK is yet another LEO satellite project which provides global integrated services for 'business' communications. It utilizes packet rather then circuit switching in both terrestrial and satellite chains as well as cellular approach for frequencies use. Original multiple access protocols and decentralized network control make it possible to organize regionally or logically independent and world-wide networks. Relatively small number of satellites (28) provides virtually global network coverage.

The Satellite Data Thematic Core Service within the EPOS Research Infrastructure

Science.gov (United States)

Manunta, Michele; Casu, Francesco; Zinno, Ivana; De Luca, Claudio; Buonanno, Sabatino; Zeni, Giovanni; Wright, Tim; Hooper, Andy; Diament, Michel; Ostanciaux, Emilie; Mandea, Mioara; Walter, Thomas; Maccaferri, Francesco; Fernandez, Josè; Stramondo, Salvatore; Bignami, Christian; Bally, Philippe; Pinto, Salvatore; Marin, Alessandro; Cuomo, Antonio

2017-04-01

EPOS, the European Plate Observing System, is a long-term plan to facilitate the integrated use of data, data products, software and services, available from distributed Research Infrastructures (RI), for solid Earth science in Europe. Indeed, EPOS integrates a large number of existing European RIs belonging to several fields of the Earth science, from seismology to geodesy, near fault and volcanic observatories as well as anthropogenic hazards. The EPOS vision is that the integration of the existing national and trans-national research infrastructures will increase access and use of the multidisciplinary data recorded by the solid Earth monitoring networks, acquired in laboratory experiments and/or produced by computational simulations. The establishment of EPOS will foster the interoperability of products and services in the Earth science field to a worldwide community of users. Accordingly, the EPOS aim is to integrate the diverse and advanced European Research Infrastructures for solid Earth science, and build on new e-science opportunities to monitor and understand the dynamic and complex solid-Earth System. One of the EPOS Thematic Core Services (TCS), referred to as Satellite Data, aims at developing, implementing and deploying advanced satellite data products and services, mainly based on Copernicus data (namely Sentinel acquisitions), for the Earth science community. This work intends to present the technological enhancements, fostered by EPOS, to deploy effective satellite services in a harmonized and integrated way. In particular, the Satellite Data TCS will deploy five services, EPOSAR, GDM, COMET, 3D-Def and MOD, which are mainly based on the exploitation of SAR data acquired by the Sentinel-1 constellation and designed to provide information on Earth surface displacements. In particular, the planned services will provide both advanced DInSAR products (deformation maps, velocity maps, deformation time series) and value-added measurements (source model

Definition of technology development missions for early space station satellite servicing, volume 2

Science.gov (United States)

1983-01-01

The results of all aspects of the early space station satellite servicing study tasks are presented. These results include identification of servicing tasks (and locations), identification of servicing mission system and detailed objectives, functional/operational requirements analyses of multiple servicing scenarios, assessment of critical servicing technology capabilities and development of an evolutionary capability plan, design and validation of selected servicing technology development missions (TDMs), identification of space station satellite servicing accommodation needs, and the cost and schedule implications of acquiring both required technology capability development and conducting the selected TDMs.

Individual Global Navigation Satellite Systems in the Space Service Volume

Science.gov (United States)

Force, Dale A.

2015-01-01

Besides providing position, navigation, and timing (PNT) to terrestrial users, GPS is currently used to provide for precision orbit determination, precise time synchronization, real-time spacecraft navigation, and three-axis control of Earth orbiting satellites. With additional Global Navigation Satellite Systems (GNSS) coming into service (GLONASS, Beidou, and Galileo), it will be possible to provide these services by using other GNSS constellations. The paper, "GPS in the Space Service Volume," presented at the ION GNSS 19th International Technical Meeting in 2006 (Ref. 1), defined the Space Service Volume, and analyzed the performance of GPS out to 70,000 km. This paper will report a similar analysis of the performance of each of the additional GNSS and compare them with GPS alone. The Space Service Volume, defined as the volume between 3,000 km altitude and geosynchronous altitude, as compared with the Terrestrial Service Volume between the surface and 3,000 km. In the Terrestrial Service Volume, GNSS performance will be similar to performance on the Earth's surface. The GPS system has established signal requirements for the Space Service Volume. A separate paper presented at the conference covers the use of multiple GNSS in the Space Service Volume.

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

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Technical requirements for space stations in the Fixed-Satellite Service. 25.210 Section 25.210 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.210 Technical...

Integration of Commercial Mobile Satellite Services into Naval Communications

National Research Council Canada - National Science Library

Stone, Cary

1997-01-01

Mobile Satellite Services (MSS) need to be integrated into Naval Communications. DoD SATCOM military owned systems fall well short of meeting DoD SATCOM requirements in general and mobile SATCOM specifically...

The determinations of remote sensing satellite data delivery service quality: A positivistic case study in Chinese context

Science.gov (United States)

Jin, Jiahua; Yan, Xiangbin; Tan, Qiaoqiao; Li, Yijun

2014-03-01

With the development of remote sensing technology, remote-sensing satellite has been widely used in many aspects of national construction. Big data with different standards and massive users with different needs, make the satellite data delivery service to be a complex giant system. How to deliver remote-sensing satellite data efficiently and effectively is a big challenge. Based on customer service theory, this paper proposes a hierarchy conceptual model for examining the determinations of remote-sensing satellite data delivery service quality in the Chinese context. Three main dimensions: service expectation, service perception and service environment, and 8 sub-dimensions are included in the model. Large amount of first-hand data on the remote-sensing satellite data delivery service have been obtained through field research, semi-structured questionnaire and focused interview. A positivist case study is conducted to validate and develop the proposed model, as well as to investigate the service status and related influence mechanisms. Findings from the analysis demonstrate the explanatory validity of the model, and provide potentially helpful insights for future practice.

The determinations of remote sensing satellite data delivery service quality: A positivistic case study in Chinese context

International Nuclear Information System (INIS)

Jin, Jiahua; Yan, Xiangbin; Tan, Qiaoqiao; Li, Yijun

2014-01-01

With the development of remote sensing technology, remote-sensing satellite has been widely used in many aspects of national construction. Big data with different standards and massive users with different needs, make the satellite data delivery service to be a complex giant system. How to deliver remote-sensing satellite data efficiently and effectively is a big challenge. Based on customer service theory, this paper proposes a hierarchy conceptual model for examining the determinations of remote-sensing satellite data delivery service quality in the Chinese context. Three main dimensions: service expectation, service perception and service environment, and 8 sub-dimensions are included in the model. Large amount of first-hand data on the remote-sensing satellite data delivery service have been obtained through field research, semi-structured questionnaire and focused interview. A positivist case study is conducted to validate and develop the proposed model, as well as to investigate the service status and related influence mechanisms. Findings from the analysis demonstrate the explanatory validity of the model, and provide potentially helpful insights for future practice

Telecommunications: Issues in Providing Cable and Satellite Television Services

Science.gov (United States)

2002-10-01

This report provides information on (1) whether the availability of cable modem Internet access service appears to be affecting the competitiveness of direct broadcast satellite (DBS) companies in the provision of video services, (2) whether cable prices and DBS penetration rates appear to be affected in areas where the DBS companies offer local broadcast channels, and (3) whether the two individual DBS companies are technologically capable of expanding local broadcast channel services into all 210 television markets in the United States.

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

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Technical requirements for space stations in the Direct Broadcast Satellite Service. 25.215 Section 25.215 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards § 25.215...

47 CFR 25.142 - Licensing provisions for the non-voice, non-geostationary mobile-satellite service.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Licensing provisions for the non-voice, non-geostationary mobile-satellite service. 25.142 Section 25.142 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses Space...

Satellites vs. fiber optics based networks and services - Road map to strategic planning

Science.gov (United States)

Marandi, James H. R.

An overview of a generic telecommunications network and its components is presented, and the current developments in satellite and fiber optics technologies are discussed with an eye on the trends in industry. A baseline model is proposed, and a cost comparison of fiber- vs satellite-based networks is made. A step-by-step 'road map' to the successful strategic planning of telecommunications services and facilities is presented. This road map provides for optimization of the current and future networks and services through effective utilization of both satellites and fiber optics. The road map is then applied to different segments of the telecommunications industry and market place, to show its effectiveness for the strategic planning of executives of three types: (1) those heading telecommunications manufacturing concerns, (2) those leading communication service companies, and (3) managers of telecommunication/MIS departments of major corporations. Future networking issues, such as developments in integrated-services digital network standards and technologies, are addressed.

Satellite switching concepts for European business services in the nineties

Science.gov (United States)

Lombard, D.; Rouffet, D.

A first generation of business communication satellites are now operational or to be launched. Increased demands for communication satellite facilities will develop, if special services, such as videoconferencing, can be provided at a reasonable cost. For such developments, it will be necessary to define a second generation of business communication satellites. The present investigation evaluates briefly the size of the expected European market for 1995. A study is conducted of the payload structure for the required satellite system, and aspects related to link budgets and power consumption are explored. It is found that system dimensioning is determined by the up-link and by technology. Critical factors are related to the output and input multiplexors for the link budget, the switching matrix, and implications for the mass budget. The best trade-off between technological, mass, and link budget limitations is achieved in connection with the employment of a hinged antennas satellite, using an intermediate number of spot beams and associated earth stations of reasonable size.

47 CFR 25.149 - Application requirements for ancillary terrestrial components in the mobile-satellite service...

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Application requirements for ancillary terrestrial components in the mobile-satellite service networks operating in the 1.5./1.6 GHz, 1.6/2.4 GHz and 2 GHz mobile-satellite service. 25.149 Section 25.149 Telecommunication FEDERAL COMMUNICATIONS...

Pattern Decomposition Method and a New Vegetation Index for Hyper-Multispectral Satellite Data Analysis

Science.gov (United States)

Muramatsu, K.; Furumi, S.; Hayashi, A.; Shiono, Y.; Ono, A.; Fujiwara, N.; Daigo, M.; Ochiai, F.

We have developed the ``pattern decomposition method'' based on linear spectral mixing of ground objects for n-dimensional satellite data. In this method, spectral response patterns for each pixel in an image are decomposed into three components using three standard spectral shape patterns determined from the image data. Applying this method to AMSS (Airborne Multi-Spectral Scanner) data, eighteen-dimensional data are successfully transformed into three-dimensional data. Using the three components, we have developed a new vegetation index in which all the multispectral data are reflected. We consider that the index should be linear to the amount of vegetation and vegetation vigor. To validate the index, its relations to vegetation types, vegetation cover ratio, and chlorophyll contents of a leaf were studied using spectral reflectance data measured in the field with a spectrometer. The index was sensitive to vegetation types and vegetation vigor. This method and index are very useful for assessment of vegetation vigor, classifying land cover types and monitoring vegetation changes

Method and associated apparatus for capturing, servicing, and de-orbiting earth satellites using robotics

Science.gov (United States)

Cepollina, Frank J. (Inventor); Burns, Richard D. (Inventor); Holz, Jill M. (Inventor); Corbo, James E. (Inventor); Jedhrich, Nicholas M. (Inventor)

2009-01-01

This invention is a method and supporting apparatus for autonomously capturing, servicing and de-orbiting a free-flying spacecraft, such as a satellite, using robotics. The capture of the spacecraft includes the steps of optically seeking and ranging the satellite using LIDAR; and matching tumble rates, rendezvousing and berthing with the satellite. Servicing of the spacecraft may be done using supervised autonomy, which is allowing a robot to execute a sequence of instructions without intervention from a remote human-occupied location. These instructions may be packaged at the remote station in a script and uplinked to the robot for execution upon remote command giving authority to proceed. Alternately, the instructions may be generated by Artificial Intelligence (AI) logic onboard the robot. In either case, the remote operator maintains the ability to abort an instruction or script at any time, as well as the ability to intervene using manual override to teleoperate the robot.In one embodiment, a vehicle used for carrying out the method of this invention comprises an ejection module, which includes the robot, and a de-orbit module. Once servicing is completed by the robot, the ejection module separates from the de-orbit module, leaving the de-orbit module attached to the satellite for de-orbiting the same at a future time. Upon separation, the ejection module can either de-orbit itself or rendezvous with another satellite for servicing. The ability to de-orbit a spacecraft further allows the opportunity to direct the landing of the spent satellite in a safe location away from population centers, such as the ocean.

The Development of a Materials Distribution Service for a Satellite-Based Educational Telecommunications Experiment. Satellite Technology Demonstration, Technical Report No. 0501.

Science.gov (United States)

Lonsdale, Helen C.

Because 16mm film programs for classroom use are expensive and distribution is unpredictable, the Satellite Technology Demonstration (STD) established a Materials Distribution Service (MDS) to transmit material via satellite to rural sites in the Rocky Mountains. The STD leased 300 programs from Encyclopedia Britannica Educational Corporation and…

47 CFR 25.144 - Licensing provisions for the 2.3 GHz satellite digital audio radio service.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Licensing provisions for the 2.3 GHz satellite digital audio radio service. 25.144 Section 25.144 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses Space Stations § 25...

76 FR 50425 - Service Rules and Policies for the Broadcasting Satellite Service (BSS)

Science.gov (United States)

2011-08-15

... video-on-demand, to consumers in the United States and promote increased competition among satellite and... innovative services, including video, audio, data, and video-on-demand, to consumers in the United States and... variation is 26.3 km. Thus, the measurement range of 30[deg] from the X axis in the X-Z plane proposed by...

47 CFR 25.214 - Technical requirements for space stations in the satellite digital audio radio service and...

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Technical requirements for space stations in the satellite digital audio radio service and associated terrestrial repeaters. 25.214 Section 25.214 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS...

Anticipated prospects and civilian applications of Indian satellite navigation services in Sri Lanka

Directory of Open Access Journals (Sweden)

I.P. Senanayake

2013-06-01

In this paper, positive impacts of 3 Indian Navigational Satellite programmes (GAGAN, IRNSS and INSAT-MSS reporting system for the civilian applications over Sri Lanka are discussed. Other neighbouring countries covered under the footprint of Indian navigational satellite programmes can also employ these services for the location based applications productively.

Mobile satellite services for public safety, disaster mitigation and disaster medicine

Science.gov (United States)

Freibaum, Jerry

1990-01-01

Between 1967 and 1987 nearly three million lives were lost and property damage of $25 to $100 billion resulted form natural disasters that adversely affected more than 829 million people. The social and economic impacts have been staggering and are expected to grow more serious as a result of changing demographic factors. The role that the Mobile Satellite Service can play in the International Decade is discussed. MSS was not available for disaster relief operations during the recent Loma Prieta/San Francisco earthquake. However, the results of a review of the performance of seven other communication services with respect to public sector operations during and shortly after the earthquake are described. The services surveyed were: public and private telephone, mobile radio telephone, noncellular mobile radio, broadcast media, CB radio, ham radio, and government and nongovernment satellite systems. The application of MSS to disaster medicine, particularly with respect to the Armenian earthquake is also discussed.

47 CFR 101.85 - Transition of the 18.3-19.3 GHz band from the terrestrial fixed services to the fixed-satellite...

Science.gov (United States)

2010-10-01

... terrestrial fixed services to the fixed-satellite service (FSS). 101.85 Section 101.85 Telecommunication... Transition of the 18.3-19.3 GHz band from the terrestrial fixed services to the fixed-satellite service (FSS...-satellite service (FSS). The rules in this section provide for a transition period during which FSS...

Advanced payload concepts and system architecture for emerging services in Indian National Satellite Systems

Science.gov (United States)

Balasubramanian, E. P.; Rao, N. Prahlad; Sarkar, S.; Singh, D. K.

2008-07-01

Over the past two decades Indian Space Research Organization (ISRO) has developed and operationalized satellites to generate a large capacity of transponders for telecommunication service use in INSAT system. More powerful on-board transmitters are built to usher-in direct-to-home broadcast services. These have transformed the Satcom application scenario in the country. With the proliferation of satellite technology, a shift in the Indian market is witnessed today in terms of demand for new services like Broadband Internet, Interactive Multimedia, etc. While it is imperative to pay attention to market trends, ISRO is also committed towards taking the benefits of technological advancement to all round growth of our population, 70% of which dwell in rural areas. The initiatives already taken in space application related to telemedicine, tele-education and Village Resource Centres are required to be taken to a greater height of efficiency. These targets pose technological challenges to build a large capacity and cost-effective satellite system. This paper addresses advanced payload concepts and system architecture along with the trade-off analysis on design parameters in proposing a new generation satellite system capable of extending the reach of the Indian broadband structure to individual users, educational and medical institutions and enterprises for interactive services. This will be a strategic step in the evolution of INSAT system to employ advanced technology to touch every human face of our population.

47 CFR 25.145 - Licensing conditions for the Fixed-Satellite Service in the 20/30 GHz bands.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Licensing conditions for the Fixed-Satellite Service in the 20/30 GHz bands. 25.145 Section 25.145 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses Space Stations § 25...

US development and commercialization of a North American mobile satellite service

Science.gov (United States)

Arnold, Ray J.; Gray, Valerie; Freibaum, Jerry

1990-01-01

U.S. policies promoting applications and commercialization of space technology for the 'benefit of mankind,' and emphasis on international competitiveness, formed the basis of NASA's Mobile Satellite (MSAT) R&D and user experiments program to develop a commercial U.S. Mobile Satellite Service. Exemplifying this philosophy, the MSAT program targets the reduction of technical, regulatory, market, and financial risks that inhibit commercialization. The program strategy includes industry and user involvement in developing and demonstrating advanced technologies, regulatory advocacy, and financial incentives to industry. Approximately two decades of NASA's satellite communications development and demonstrations have contributed to the emergence of a new multi-billion dollar industry for land, aeronautical, and maritime mobile communications via satellite. NASA's R&D efforts are now evolving from the development of 'enabling' ground technologies for VHF, UHF, and L-Band mobile terminals, to Ka-Band terminals offering additional mobility and user convenience.

US development and commercialization of a North American mobile satellite service

Science.gov (United States)

Arnold, Ray J.; Gray, Valerie; Freibaum, Jerry

U.S. policies promoting applications and commercialization of space technology for the 'benefit of mankind,' and emphasis on international competitiveness, formed the basis of NASA's Mobile Satellite (MSAT) R&D and user experiments program to develop a commercial U.S. Mobile Satellite Service. Exemplifying this philosophy, the MSAT program targets the reduction of technical, regulatory, market, and financial risks that inhibit commercialization. The program strategy includes industry and user involvement in developing and demonstrating advanced technologies, regulatory advocacy, and financial incentives to industry. Approximately two decades of NASA's satellite communications development and demonstrations have contributed to the emergence of a new multi-billion dollar industry for land, aeronautical, and maritime mobile communications via satellite. NASA's R&D efforts are now evolving from the development of 'enabling' ground technologies for VHF, UHF, and L-Band mobile terminals, to Ka-Band terminals offering additional mobility and user convenience.

The Development of a Field Services Network for a Satellite-Based Educational Telecommunications Experiment. Satellite Technology Demonstration, Technical Report No. 0333.

Science.gov (United States)

Anderson, Frank; And Others

The Satellite Technology Demonstration (STD) of the Federation of Rocky Mountain States (FRMS) employed a technical delivery system to merge effectively hardware and software, products and services. It also needed a nontechnical component to insure product and service acceptance. Accordingly, the STD's Utilization Component was responsible for…

Definition of satellite servicing technology development missions for early space stations. Volume 2: Technical

Science.gov (United States)

1983-01-01

Early space station accommodation, build-up of space station manipulator capability, on-orbit spacecraft assembly test and launch, large antenna structure deployment, service/refurbish satellite, and servicing of free-flying materials processing platform are discussed.

Satellite provided customer premise services: A forecast of potential domestic demand through the year 2000. Volume 2: Technical report

Science.gov (United States)

Kratochvil, D.; Bowyer, J.; Bhushan, C.; Steinnagel, K.; Al-Kinani, G.

1983-08-01

The potential United States domestic telecommunications demand for satellite provided customer premises voice, data and video services through the year 2000 were forecast, so that this information on service demand would be available to aid in NASA program planning. To accomplish this overall purpose the following objectives were achieved: development of a forecast of the total domestic telecommunications demand, identification of that portion of the telecommunications demand suitable for transmission by satellite systems, identification of that portion of the satellite market addressable by Computer premises services systems, identification of that portion of the satellite market addressabble by Ka-band CPS system, and postulation of a Ka-band CPS network on a nationwide and local level. The approach employed included the use of a variety of forecasting models, a market distribution model and a network optimization model. Forecasts were developed for; 1980, 1990, and 2000; voice, data and video services; terrestrial and satellite delivery modes; and C, Ku and Ka-bands.

Mobile satellite service communications tests using a NASA satellite

Science.gov (United States)

Chambers, Katherine H.; Koschmeder, Louis A.; Hollansworth, James E.; ONeill, Jack; Jones, Robert E.; Gibbons, Richard C.

1995-01-01

Emerging applications of commercial mobile satellite communications include satellite delivery of compact disc (CD) quality radio to car drivers who can select their favorite programming as they drive any distance; transmission of current air traffic data to aircraft; and handheld communication of data and images from any remote corner of the world. Experiments with the enabling technologies and tests and demonstrations of these concepts are being conducted before the first satellite is launched by utilizing an existing NASA spacecraft.

Telecommunication service markets through the year 2000 in relation to millimeter wave satellite systems

Science.gov (United States)

Stevenson, S. M.

1979-01-01

NASA is currently conducting a series of millimeter wave satellite system and market studies to develop 30/20 GHz satellite system concepts that have commercial potential for the period 1980-2000. The results of the market studies to-date focusing on the overall demand forecasts and distributions by geographic location, distance, and user category are discussed. Tables are presented indicating baseline market forecast voice and video services, data service category, impacted baseline forecast, and traffic/distance distribution voice services. It is concluded that the total market and system activity will be influential in determining the potential role of millimeter wave systems in the overall transmission needs of the nation, and the amount of the total forecasted traffic suitable for millimeter wave systems.

Communication satellite applications

Science.gov (United States)

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.

Transportation Satellite Accounts : A New Way of Measuring Transportation Services in America

Science.gov (United States)

2011-01-01

Transportation Satellite Accounts (TSA), produced by the Bureau of Economic Analysis and the Bureau of Transportation Statistics, provides measures of national transportation output. TSA includes both in-house and for-hire transportation services. Fo...

Satellite provided customer promises services, a forecast of potential domestic demand through the year 2000. Volume 4: Sensitivity analysis

Science.gov (United States)

Kratochvil, D.; Bowyer, J.; Bhushan, C.; Steinnagel, K.; Kaushal, D.; Al-Kinani, G.

1984-03-01

The overall purpose was to forecast the potential United States domestic telecommunications demand for satellite provided customer promises voice, data and video services through the year 2000, so that this information on service demand would be available to aid in NASA program planning. To accomplish this overall purpose the following objectives were achieved: (1) development of a forecast of the total domestic telecommunications demand; (2) identification of that portion of the telecommunications demand suitable for transmission by satellite systems; (3) identification of that portion of the satellite market addressable by consumer promises service (CPS) systems; (4) identification of that portion of the satellite market addressable by Ka-band CPS system; and (5) postulation of a Ka-band CPS network on a nationwide and local level. The approach employed included the use of a variety of forecasting models, a parametric cost model, a market distribution model and a network optimization model. Forecasts were developed for: 1980, 1990, and 2000; voice, data and video services; terrestrial and satellite delivery modes; and C, Ku and Ka-bands.

Mobile satellite communications in the 1990's

Science.gov (United States)

Singh, Jai

1992-07-01

The evolution of Inmarsat global services from a single market and single service of the 1980's to all of the key mobile markets and a wide range of new terminals and services in the 1990's is described. An overview of existing mobile satellite services, as well as new services under implementation for introduction in the near and longer term, including a handheld satellite phone (Inmarsat-P), is provided. The initiative taken by Inmarsat in the integration of its global mobile satellite services with global navigation capability derived from GPS (Global Positioning System) and the GLONASS (Russian GPS) navigation satellite systems and the provision of an international civil overlay for GPS/GLONASS integrity and augmentation is highlighted. To complete the overview of the development of mobile satellite services in the 1990's, the known national and regional mobile satellite system plans and the various recent proposals for both orbiting and geostationary satellite systems for proving handheld satellite phone and/or data messaging services are described.

Inmarsat and personal mobile satellite services

Science.gov (United States)

McDougal, Patrick; Barendse, Victor

Personal communications - mobile satellite services (PC-MSS) hold much promise as a profitable business opportunity for a number of interested operators and manufacturers. What will be their impact on the overall mobile communications landscape, and what role will they play in the drive towards the universal personal communicator? It is the thesis of this paper that PC-MSS can provide one of the critical enabling technologies to allow a more rapid, global assimilation of personal mobile communications. Terrestrial mobile communications are local by definition, both in terms of service reach and regulatory oversight. It is estimated that cellular, and other forms of terrestrial mobile communications, will cover over 50% of the world's population, but only 15% of the land mass area by the year 2000. PC-MSS will allow 'cellular extension' to interested users in the uncovered parts of the world. The market opportunity is established and technical solutions are available. However 'user cooperation' will be required and cross mapping of market needs to the technology solutions is the key to financially viable solutions. The potential political and regulatory hurdles are daunting. Inmarsat, as the existing global MSS partnership, is already introducing PC-MSS products and services in the 1990s. The widespread use of briefcase satphones (Inm-M), laptop-sized data terminals (Inm-C), and pocket satpagers (Inm-paging) will break new ground in reshaping the international regulatory context of mobile communications, and in initiating the optimal public switched network integration necessary for global interconnect. It is suggested that this evolutionary approach, by means of international consensus-building within a global partnership of operators, is an effective and proven method to ensure both a sufficient financial return for investors, and fair and equitable access of these services for all countries and users.

Developing Information Services and Tools to Access and Evaluate Data Quality in Global Satellite-based Precipitation Products

Science.gov (United States)

Liu, Z.; Shie, C. L.; Meyer, D. J.

2017-12-01

Global satellite-based precipitation products have been widely used in research and applications around the world. Compared to ground-based observations, satellite-based measurements provide precipitation data on a global scale, especially in remote continents and over oceans. Over the years, satellite-based precipitation products have evolved from single sensor and single algorithm to multi-sensors and multi-algorithms. As a result, many satellite-based precipitation products have been enhanced such as spatial and temporal coverages. With inclusion of ground-based measurements, biases of satellite-based precipitation products have been significantly reduced. However, data quality issues still exist and can be caused by many factors such as observations, satellite platform anomaly, algorithms, production, calibration, validation, data services, etc. The NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) is home to NASA global precipitation product archives including the Tropical Rainfall Measuring Mission (TRMM), the Global Precipitation Measurement (GPM), as well as other global and regional precipitation products. Precipitation is one of the top downloaded and accessed parameters in the GES DISC data archive. Meanwhile, users want to easily locate and obtain data quality information at regional and global scales to better understand how precipitation products perform and how reliable they are. As data service providers, it is necessary to provide an easy access to data quality information, however, such information normally is not available, and when it is available, it is not in one place and difficult to locate. In this presentation, we will present challenges and activities at the GES DISC to address precipitation data quality issues.

A Methodology for Selection of a Satellite Servicing Architecture. Volume 3. Appendices.

Science.gov (United States)

1985-12-01

model transfers between inclined circu- lar orbits. If OSV time of flight becomes more critical . then a choice between the other two techniques is...ABSTRACT iContinue on ,viverse if necesary and identify by block, number) Title: A METODO ~LOGY FOR SELECION~ OF A SATELLITE SERVICING ARCHITEIR VOLUME

Global Mobile Satellite Service Interference Analysis for the AeroMACS

Science.gov (United States)

Wilson, Jeffrey D.; Apaza, Rafael D.; Hall, Ward; Phillips, Brent

2013-01-01

The AeroMACS (Aeronautical Mobile Airport Communications System), which is based on the IEEE 802.16-2009 mobile wireless standard, is envisioned as the wireless network which will cover all areas of airport surfaces for next generation air transportation. It is expected to be implemented in the 5091-5150 MHz frequency band which is also occupied by mobile satellite service uplinks. Thus the AeroMACS must be designed to avoid interference with this incumbent service. Simulations using Visualyse software were performed utilizing a global database of 6207 airports. Variations in base station and subscriber antenna distribution and gain pattern were examined. Based on these simulations, recommendations for global airport base station and subscriber antenna power transmission limitations are provided.

Hybrid Terrestrial-Satellite DVB/IP Infrastructure in Overlay Constellations for Triple-Play Services Access in Rural Areas

Directory of Open Access Journals (Sweden)

E. Pallis

2010-01-01

Full Text Available This paper discusses the convergence of digital broadcasting and Internet technologies, by elaborating on the design, implementation, and performance evaluation of a hybrid terrestrial/satellite networking infrastructure, enabling triple-play services access in rural areas. At local/district level, the paper proposes the exploitation of DVB-T platforms in regenerative configurations for creating terrestrial DVB/IP backhaul between the core backbone (in urban areas and a number of intermediate communication nodes distributed within the DVB-T broadcasting footprint (in rural areas. In this way, triple play services that are available at the core backbone, are transferred via the regenerative DVB-T/IP backhaul to the entire district and can be accessed by rural users via the corresponding intermediate node. On the other hand, at regional/national level, the paper proposes the exploitation of a satellite interactive digital video broadcasting platform (DVB S2/RCS as an overlay network that interconnects the regenerative DVB-T/IP platforms, as well as individual users, and services providers, to each other. Performance of the proposed hybrid terrestrial/satellite networking environment is validated through experimental tests that were conducted under real transmission/reception conditions (for the terrestrial segment and via simulation experiments (for the satellite segment at a prototype network infrastructure.

Odyssey, an optimized personal communications satellite system

Science.gov (United States)

Rusch, Roger J.

Personal communications places severe demands on service providers and transmission facilities. Customers are not satisfied with the current levels of service and want improvements. Among the characteristics that users seek are: lower service rates, hand held convenience, acceptable time delays, ubiquitous service, high availability, reliability, and high quality. The space industry is developing commercial space systems for providing mobile communications to personal telephones. Provision of land mobile satellite service is fundamentally different from the fixed satellite service provided by geostationary satellites. In fixed service, the earth based antennas can depend on a clear path from user to satellite. Mobile users in a terrestrial environment commonly encounter blockage due to vegetation, terrain or buildings. Consequently, high elevation angles are of premium value. TRW studied the issues and concluded that a Medium Earth Orbit constellation is the best solution for Personal Communications Satellite Service. TRW has developed Odyssey, which uses twelve satellites in medium altitude orbit to provide personal communications satellite service. The Odyssey communications system projects a multibeam antenna pattern to the Earth. The attitude control system orients the satellites to ensure constant coverage of land mass and coastal areas. Pointing can be reprogrammed by ground control to ensure optimized coverage of the desired service areas. The payload architecture features non-processing, "bent pipe" transponders and matrix amplifiers to ensure dynamic power delivery to high demand areas. Circuit capacity is 3000 circuits per satellite. Each satellite weighs 1917 kg (4226 pounds) at launch and the solar arrays provide 3126 Watts of power. Satellites are launched in pairs on Ariane, Atlas, or other vehicles. Each satellite is placed in a circular orbit at an altitude of 10,354 km. There are three orbit planes inclined at 55° to the equatorial plane

ATM Quality of Service Tests for Digitized Video Using ATM Over Satellite: Laboratory Tests

Science.gov (United States)

Ivancic, William D.; Brooks, David E.; Frantz, Brian D.

1997-01-01

A digitized video application was used to help determine minimum quality of service parameters for asynchronous transfer mode (ATM) over satellite. For these tests, binomially distributed and other errors were digitally inserted in an intermediate frequency link via a satellite modem and a commercial gaussian noise generator. In this paper, the relation- ship between the ATM cell error and cell loss parameter specifications is discussed with regard to this application. In addition, the video-encoding algorithms, test configurations, and results are presented in detail.

Land Mobile Satellite Service (LMSS): A conceptual system design and identification of the critical technologies. Part 1: Executive summary

Science.gov (United States)

Naderi, F. (Editor)

1982-01-01

A system design for a satellite aided land mobile service is described. The advanced system is based on a geostationary satellite which employs a large UHF reflector to communicate with small user antennas on mobile vehicles. It is shown that the system through multiple beam antennas and frequency reuse provides for radiotelephone and dispatch channels. It is concluded that the system is technologically feasible to provide service to rural and remote regions.

Telecommunication service markets through the year 2000 in relation to millimeter wave satellite systems

Science.gov (United States)

Stevenson, S. M.

1979-01-01

NASA is currently conducting a series of millimeter wave satellite system market studies to develop 30/20 GHz satellite system concepts that have commercial potential. Four contractual efforts were undertaken: two parallel and independent system studies and two parallel and independent market studies. The marketing efforts are focused on forecasting the total domestic demand for long haul telecommunications services for the 1980-2000 period. Work completed to date and reported in this paper include projections of: geographical distribution of traffic; traffic volume as a function of urban area size; and user identification and forecasted demand.

Activities of Canadian Satellite Communications, Inc.

Science.gov (United States)

1992-12-01

Canadian Satellite Communications (Cancom) has as its core business the provision of television and radio signals to cable systems in Canada, with the objective of making affordable broadcast signals available to remote and/or small communities. Cancom also provides direct-to-home services to backyard receiving dishes, as well as satellite digital data business communications services, satellite business television, and satellite network services. Its business communication services range from satellite links for big-city businesses with small branch operations located far from major centers, to a mobile messaging and tracking system for the trucking industry. Revenues in 1992 totalled $48,212,000 and net income was just over $7 million. Cancom bought 10 percent interest in Leosat Corp. of Washington, DC, who are seeking approval to operate a position locator network from low-orbit satellites. Cancom has also become a partner in SovCan Star Satellite Communications Inc., which will build an international satellite system in partnership with Russia. The first satellite in this east-west business network will be placed in a Russian orbital slot over the Atlantic by 1996, and a second satellite will follow for the Pacific region. This annual report of Cancom's activities for 1992 includes financial statements and a six year financial review.

Using Participatory and Service Design to Identify Emerging Needs and Perceptions of Library Services among Science and Engineering Researchers Based at a Satellite Campus

Science.gov (United States)

Johnson, Andrew; Kuglitsch, Rebecca; Bresnahan, Megan

2015-01-01

This study used participatory and service design methods to identify emerging research needs and existing perceptions of library services among science and engineering faculty, post-graduate, and graduate student researchers based at a satellite campus at the University of Colorado Boulder. These methods, and the results of the study, allowed us…

The satellite situation center

International Nuclear Information System (INIS)

Teague, M.J.; Sawyer, D.M.; Vette, J.I.

1982-01-01

Considerations related to the early planning for the International Magnetospheric Study (IMS) took into account the desirability of an establishment of specific entities for generating and disseminating coordination information for both retrospective and predictive periods. The organizations established include the IMS/Satellite Situation Center (IMS/SSC) operated by NASA. The activities of the SSC are related to the preparation of reports on predicted and actually achieved satellite positions, the response to inquiries, the compilation of information on satellite experiments, and the issue of periodic status summaries. Attention is given to high-altitude satellite services, other correlative satellite services, non-IMS activities of the SSC, a summary of the SSC request activity, and post-IMS and future activities

Land Mobile Satellite Service (LMSS): A conceptual system design and identification of the critical technologies: Part 2: Technical report

Science.gov (United States)

Naderi, F. (Editor)

1982-01-01

A conceptual system design for a satellite-aided land mobile service is described. A geostationary satellite which employs a large (55-m) UHF reflector to communicate with small inexpensive user antennas on mobile vehicles is discussed. It is shown that such a satellite system through multiple beam antennas and frequency reuse can provide thousands of radiotelephone and dispatch channels serving hundreds of thousands of users throughout the U.S.

Satellite-enabled educational services specification and requirements analysis based on user feedback

OpenAIRE

Tsekeridou, Sofia; Tiropanis, Thanassis; Rorris, Dimitris; Constantinos, Makropoulos; Serif, Tacha; Stergioulas, Lampros

2008-01-01

Advanced tele-education services provision in remote geographically dispersed user communities (such as agriculture and maritime), based on the specific needs and requirements of such communities, implies significant infrastructural and broadband connectivity requirements for rich media, timely and quality-assured content delivery and interactivity. The solution to broadband access anywhere is provided by satellite-enabled communication infrastructures. This paper aims to present such satelli...

ATM Quality of Service Parameters at 45 Mbps Using a Satellite Emulator: Laboratory Measurements

Science.gov (United States)

Ivancic, William D.; Bobinsky, Eric A.

1997-01-01

Results of 45-Mbps DS3 intermediate-frequency loopback measurements of asynchronous transfer mode (ATM) quality of service parameters (cell error ratio and cell loss ratio) are presented. These tests, which were conducted at the NASA Lewis Research Center in support of satellite-ATM interoperability research, represent initial efforts to quantify the minimum parameters for stringent ATM applications, such as MPEG-1 and MPEG-2 video transmission. Portions of these results were originally presented to the International Telecommunications Union's ITU-R Working Party 4B in February 1996 in support of their Draft Preliminary Recommendation on the Transmission of ATM Traffic via Satellite.

A GeoServices Infrastructure for Near-Real-Time Access to Suomi NPP Satellite Data

Science.gov (United States)

Evans, J. D.; Valente, E. G.; Hao, W.; Chettri, S.

2012-12-01

The new Suomi National Polar-orbiting Partnership (NPP) satellite extends NASA's moderate-resolution, multispectral observations with a suite of powerful imagers and sounders to support a broad array of research and applications. However, NPP data products consist of a complex set of data and metadata files in highly specialized formats; which NPP's operational ground segment delivers to users only with several hours' delay. This severely limits their use in critical applications such as weather forecasting, emergency / disaster response, search and rescue, and other activities that require near-real-time access to satellite observations. Alternative approaches, based on distributed Direct Broadcast facilities, can reduce the delay in NPP data delivery from hours to minutes, and can make products more directly usable by practitioners in the field. To assess and fulfill this potential, we are developing a suite of software that couples Direct Broadcast data feeds with a streamlined, scalable processing chain and geospatial Web services, so as to permit many more time-sensitive applications to use NPP data. The resulting geoservices infrastructure links a variety of end-user tools and applications to NPP data from different sources, and to other rapidly-changing geospatial data. By using well-known, standard software interfaces (such as OGC Web Services or OPeNDAP), this infrastructure serves a variety of end-user analysis and visualization tools, giving them access into datasets of arbitrary size and resolution and allowing them to request and receive tailored products on demand. The standards-based approach may also streamline data sharing among independent satellite receiving facilities, thus helping them to interoperate in providing frequent, composite views of continent-scale or global regions. To enable others to build similar or derived systems, the service components we are developing (based in part on the Community Satellite Processing Package (CSPP) from

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

Science.gov (United States)

2013-03-29

... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 2 and 25 [IB Docket No. 12-376; FCC 12-161] Earth Stations Aboard Aircraft Communicating with Fixed-Satellite Service Geostationary-Orbit Space Stations... the Federal Register of March 8, 2013. The document proposed rules for Earth Stations Aboard Aircraft...

Space Network IP Services (SNIS): An Architecture for Supporting Low Earth Orbiting IP Satellite Missions

Science.gov (United States)

Israel, David J.

2005-01-01

The NASA Space Network (SN) supports a variety of missions using the Tracking and Data Relay Satellite System (TDRSS), which includes ground stations in White Sands, New Mexico and Guam. A Space Network IP Services (SNIS) architecture is being developed to support future users with requirements for end-to-end Internet Protocol (IP) communications. This architecture will support all IP protocols, including Mobile IP, over TDRSS Single Access, Multiple Access, and Demand Access Radio Frequency (RF) links. This paper will describe this architecture and how it can enable Low Earth Orbiting IP satellite missions.

Towards Improved Satellite-In Situ Oceanographic Data Interoperability and Associated Value Added Services at the Podaac

Science.gov (United States)

Tsontos, V. M.; Huang, T.; Holt, B.

2015-12-01

The earth science enterprise increasingly relies on the integration and synthesis of multivariate datasets from diverse observational platforms. NASA's ocean salinity missions, that include Aquarius/SAC-D and the SPURS (Salinity Processes in the Upper Ocean Regional Study) field campaign, illustrate the value of integrated observations in support of studies on ocean circulation, the water cycle, and climate. However, the inherent heterogeneity of resulting data and the disparate, distributed systems that serve them complicates their effective utilization for both earth science research and applications. Key technical interoperability challenges include adherence to metadata and data format standards that are particularly acute for in-situ data and the lack of a unified metadata model facilitating archival and integration of both satellite and oceanographic field datasets. Here we report on efforts at the PO.DAAC, NASA's physical oceanographic data center, to extend our data management and distribution support capabilities for field campaign datasets such as those from SPURS. We also discuss value-added services, based on the integration of satellite and in-situ datasets, which are under development with a particular focus on DOMS. The distributed oceanographic matchup service (DOMS) implements a portable technical infrastructure and associated web services that will be broadly accessible via the PO.DAAC for the dynamic collocation of satellite and in-situ data, hosted by distributed data providers, in support of mission cal/val, science and operational applications.

Design Issues for Traffic Management for the ATM UBR + Service for TCP Over Satellite Networks

Science.gov (United States)

Jain, Raj

1999-01-01

This project was a comprehensive research program for developing techniques for improving the performance of Internet protocols over Asynchronous Transfer Mode (ATM) based satellite networks. Among the service categories provided by ATM networks, the most commonly used category for data traffic is the unspecified bit rate (UBR) service. UBR allows sources to send data into the network without any feedback control. The project resulted in the numerous ATM Forum contributions and papers.

Potential markets for advanced satellite communications

Science.gov (United States)

Adamson, Steven; Roberts, David; Schubert, Leroy; Smith, Brian; Sogegian, Robert; Walters, Daniel

1993-09-01

This report identifies trends in the volume and type of traffic offered to the U.S. domestic communications infrastructure and extrapolates these trends through the year 2011. To describe how telecommunications service providers are adapting to the identified trends, this report assesses the status, plans, and capacity of the domestic communications infrastructure. Cable, satellite, and radio components of the infrastructure are examined separately. The report also assesses the following major applications making use of the infrastructure: (1) Broadband services, including Broadband Integrated Services Digital Network (BISDN), Switched Multimegabit Data Service (SMDS), and frame relay; (2) mobile services, including voice, location, and paging; (3) Very Small Aperture Terminals (VSAT), including mesh VSAT; and (4) Direct Broadcast Satellite (DBS) for audio and video. The report associates satellite implementation of specific applications with market segments appropriate to their features and capabilities. The volume and dollar value of these market segments are estimated. For the satellite applications able to address the needs of significant market segments, the report also examines the potential of each satellite-based application to capture business from alternative technologies.

Potential markets for advanced satellite communications

Science.gov (United States)

Adamson, Steven; Roberts, David; Schubert, Leroy; Smith, Brian; Sogegian, Robert; Walters, Daniel

1993-01-01

This report identifies trends in the volume and type of traffic offered to the U.S. domestic communications infrastructure and extrapolates these trends through the year 2011. To describe how telecommunications service providers are adapting to the identified trends, this report assesses the status, plans, and capacity of the domestic communications infrastructure. Cable, satellite, and radio components of the infrastructure are examined separately. The report also assesses the following major applications making use of the infrastructure: (1) Broadband services, including Broadband Integrated Services Digital Network (BISDN), Switched Multimegabit Data Service (SMDS), and frame relay; (2) mobile services, including voice, location, and paging; (3) Very Small Aperture Terminals (VSAT), including mesh VSAT; and (4) Direct Broadcast Satellite (DBS) for audio and video. The report associates satellite implementation of specific applications with market segments appropriate to their features and capabilities. The volume and dollar value of these market segments are estimated. For the satellite applications able to address the needs of significant market segments, the report also examines the potential of each satellite-based application to capture business from alternative technologies.

Sharing the 620-790 MHz band allocated to terrestrial television with an audio-bandwidth social service satellite system

Science.gov (United States)

Smith, E. K.; Reinhart, E. E.

1977-01-01

A study was carried out to identify the optimum uplink and downlink frequencies for audio-bandwidth channels for use by a satellite system distributing social services. The study considered functional-user-need models for five types of social services and identified a general baseline system that is appropriate for most of them. Technical aspects and costs of this system and of the frequency bands that it might use were reviewed, leading to the identification of the 620-790 MHz band as a perferred candidate for both uplink and downlink transmissions for nonmobile applications. The study also led to some ideas as to how to configure the satellite system.

Cyberinfrastructure Initiatives of the Committee on Earth Observation Satellites (CEOS) Working Group on Information Systems and Services (WGISS)

Science.gov (United States)

McDonald, K. R.; Faundeen, J. L.; Petiteville, I.

2005-12-01

The Committee on Earth Observation Satellites (CEOS) was established in 1984 in response to a recommendation from the Economic Summit of Industrialized Nations Working Group on Growth, Technology, and Employment's Panel of Experts on Satellite Remote Sensing. CEOS participants are Members, who are national or international governmental organizations who operate civil spaceborne Earth observation satellites, and Associates who are governmental organizations with civil space programs in development or international scientific or governmental bodies who have an interest in and support CEOS objectives. The primary objective of CEOS is to optimize benefits of satellite Earth observations through cooperation of its participants in mission planning and in development of compatible data products, formats, services, applications and policies. To pursue its objectives, CEOS establishes working groups and associated subgroups that focus on relevant areas of interest. While the structure of CEOS has evolved over its lifetime, today there are three permanent working groups. One is the Working Group on Calibration and Validation that addresses sensor-specific calibration and validation and geophysical parameter validation. A second is the Working Group on Education, Training, and Capacity Building that facilitates activities that enhance international education and training in Earth observation techniques, data analysis, interpretation and applications, with a particular focus on developing countries. The third permanent working group is the Working Group on Information Systems and Services (WGISS). The purpose of WGISS is to promote collaboration in the development of the systems and services based on international standards that manage and supply the Earth observation data and information from participating agencies' missions. WGISS places great emphasis on the use of demonstration projects involving user groups to solve the critical interoperability issues associated with the

A FD/DAMA network architecture for the first generation land mobile satellite services

Science.gov (United States)

Yan, T.-Y.; Wang, C.; Cheng, U.; Dessouky, K.; Rafferty, W.

1989-01-01

A frequency division/demand assigned multiple access (FD/DAMA) network architecture for the first-generation land mobile satellite services is presented. Rationales and technical approaches are described. In this architecture, each mobile subscriber must follow a channel access protocol to make a service request to the network management center before transmission for either open-end or closed-end services. Open-end service requests will be processed on a blocked call cleared basis, while closed-end requests will be processed on a first-come-first-served basis. Two channel access protocols are investigated, namely, a recently proposed multiple channel collision resolution scheme which provides a significantly higher useful throughput, and the traditional slotted Aloha scheme. The number of channels allocated for either open-end or closed-end services can be adaptively changed according to aggregated traffic requests. Both theoretical and simulation results are presented. Theoretical results have been verified by simulation on the JPL network testbed.

Interworking evolution of mobile satellite and terrestrial networks

Science.gov (United States)

Matyas, R.; Kelleher, P.; Moller, P.; Jones, T.

1993-01-01

There is considerable interest among mobile satellite service providers in interworking with terrestrial networks to provide a universal global network. With such interworking, subscribers may be provided a common set of services such as those planned for the Public Switched Telephone Network (PSTN), the Integrated Services Digital Network (ISDN), and future Intelligent Networks (IN's). This paper first reviews issues in satellite interworking. Next the status and interworking plans of terrestrial mobile communications service providers are examined with early examples of mobile satellite interworking including a discussion of the anticipated evolution towards full interworking between mobile satellite and both fixed and mobile terrestrial networks.

Establishing a Robotic, LEO-to-GEO Satellite Servicing Infrastructure as an Economic Foundation for Exploration

Science.gov (United States)

Horsham, Gary A. P.; Schmidt, George R.; Gilland, James H.

2010-01-01

The strategy for accomplishing civilian exploration goals and objectives is in the process of a fundamental shift towards a potential new approach called Flexible Path. This paper suggests that a government-industry or public-private partnership in the commercial development of low Earth orbit to geostationary orbit (LEO-to-GEO (LTG)) space, following or in parallel with the commercialization of Earth-to-LEO and International Space Station (ISS) operations, could serve as a necessary, logical step that can be incorporated into the flexible path approach. A LTG satellite-servicing infrastructure and architecture concept is discussed within this new strategic context. The concept consists of a space harbor that serves as a transport facility for a fleet of specialized, fully- or semi-autonomous robotic servicing spacecraft. The baseline, conceptual system architecture is composed of a space harbor equipped with specialized servicer spacecraft; a satellite command, communication, and control system; a parts station; a fuel station or depot; and a fuel/parts replenishment transport. The commercial servicer fleet would consist of several types of spacecraft, each designed with specialized robotic manipulation subsystems to provide services such as refueling, upgrade, repair, inspection, relocation, and removal. The space harbor is conceptualized as an ISS-type, octagonal truss structure equipped with radiation tolerant subsystems. This space harbor would be primarily capable of serving as an operational platform for various commercially owned and operated servicer spacecraft positioned and docked symmetrically on four of the eight sides. Several aspects of this concept are discussed, such as: system-level feasibility in terms of ISS-truss-type infrastructure and subsystems emplacement and maintenance between LEO and GEO; infrastructure components assembly in LEO, derived from ISS assembly experience, and transfer to various higher orbital locations; the evolving Earth

Estimation of the demand for public services communications. [market research and economic analysis for a communications satellite system

Science.gov (United States)

1976-01-01

Market analyses and economic studies are presented to support NASA planning for a communications satellite system to provide public services in health, education, mobile communications, data transfer, and teleconferencing.

Security Concepts for Satellite Links

Science.gov (United States)

Tobehn, C.; Penné, B.; Rathje, R.; Weigl, A.; Gorecki, Ch.; Michalik, H.

2008-08-01

The high costs to develop, launch and maintain a satellite network makes protecting the assets imperative. Attacks may be passive such as eavesdropping on the payload data. More serious threat are active attacks that try to gain control of the satellite, which may lead to the total lost of the satellite asset. To counter these threats, new satellite and ground systems are using cryptographic technologies to provide a range of services: confidentiality, entity & message authentication, and data integrity. Additionally, key management cryptographic services are required to support these services. This paper describes the key points of current satellite control and operations, that are authentication of the access to the satellite TMTC link and encryption of security relevant TM/TC data. For payload data management the key points are multi-user ground station access and high data rates both requiring frequent updates and uploads of keys with the corresponding key management methods. For secure satellite management authentication & key negotiation algorithms as HMAC-RIPEMD160, EC- DSA and EC-DH are used. Encryption of data uses algorithms as IDEA, AES, Triple-DES, or other. A channel coding and encryption unit for payload data provides download data rates up to Nx250 Mbps. The presented concepts are based on our experience and heritage of the security systems for all German MOD satellite projects (SATCOMBw2, SAR-Lupe multi- satellite system and German-French SAR-Lupe-Helios- II systems inter-operability) as well as for further international (KOMPSAT-II Payload data link system) and ESA activities (TMTC security and GMES).

GAUSS Market Analysis for Integrated Satellite Communication and Navigation Location Based services

Science.gov (United States)

Di Fazio, Antonella; Dricot, Fabienne; Tata, Francesco

2003-07-01

The demand for mobile information services coupled with positioning technologies for delivering value- added services that depend on a user's location has rapidly increased during last years. In particular, services and applications related with improved mobility safety and transport efficiency look very attractive.Solutions for location services vary in respect of positioning accuracy and the technical infrastructure required, and the associated investment in terminals and networks. From the analysis of the state-of-the art, it comes that various technologies are currently available on the European market, while mobile industry is gearing up to launch a wide variety of location services like tracking, alarming and locating.Nevertheless, when addressing safety of life as well as security applications, severe hurdles have to be posed in the light of existing technologies. Existing navigation (e.g. GPS) and communication systems are not able to completely satisfy the needs and requirements of safety-of-life-critical applications. As a matter of fact, the GPS system's main weaknesses today is its lack of integrity, which means its inability to warn users of a malfunction in a reasonable time, while the other positioning techniques do not provide satisfactory accuracy as well, and terrestrial communication networks are not capable to cope with stringent requirement in terms of service reliability and coverage.In this context, GAUSS proposes an innovative satellite-based solution using novel technology and effective tools for addressing mobility challenges in a cost efficient manner, improving safety and effectiveness.GAUSS (Galileo And UMTS Synergetic System) is a Research and Technological Development project co- funded by European Commission, within the frame of the 5th IST Programme. The project lasted two years, and it was successfully completed in November 2002. GAUSS key concept is the integration of Satellite Navigation GNSS and UMTS communication technology, to

Definition of technology development missions for early Space Station satellite servicing. Volume 2: Technical

Science.gov (United States)

Cable, D. A.; Diewald, C. A.; Hills, T. C.; Parmentier, T. J.; Spencer, R. A.; Stone, G. E.

1984-01-01

Volume 2 contains the Technical Report of the approach and results of the Phase 2 study. The phase 2 servicing study was initiated in June 1983, and is being reported in this document. The scope of the contract was to: (1) define in detail five selected technology development missions (TDM); (2) conduct a design requirement analysis to refine definitions of satellite servicing requirements at the space station; and (3) develop a technology plan that would identify and schedule prerequisite precursor technology development, associated. STS flight experiments and space station experiments needed to provide onorbit validation of the evolving technology.

Next generation satellite communications networks

Science.gov (United States)

Garland, P. J.; Osborne, F. J.; Streibl, I.

The paper introduces two potential uses for new space hardware to permit enhanced levels of signal handling and switching in satellite communication service for Canada. One application involves increased private-sector services in the Ku band; the second supports new personal/mobile services by employing higher levels of handling and switching in the Ka band. First-generation satellite regeneration and switching experiments involving the NASA/ACTS spacecraft are described, where the Ka band and switching satellite network problems are emphasized. Second-generation satellite development is outlined based on demand trends for more packet-based switching, low-cost earth stations, and closed user groups. A demonstration mission for new Ka- and Ku-band technologies is proposed, including the payload configuration. The half ANIK E payload is shown to meet the demonstration objectives, and projected to maintain a fully operational payload for at least 10 years.

NOAA Satellite and Information Service's International and Interagency

Science.gov (United States)

: To meet the challenge of understanding and predicting changes in climate, weather, oceans, and coasts Affaris Division Skip to main content NOAA HOME NESDIS HOME WEATHER OCEANS & COASTS FISHERIES CHARTING SATELLITES CLIMATE RESEARCH CAREERS Satellite and Data Policy Developing Partnerships

A new digital land mobile satellite system

Science.gov (United States)

Schneider, Philip

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

Development of an allergy management support system in primary care

Directory of Open Access Journals (Sweden)

Flokstra - de Blok BMJ

2017-03-01

Full Text Available Bertine MJ Flokstra - de Blok,1,2 Thys van der Molen,1,2 Wianda A Christoffers,3 Janwillem WH Kocks,1,2 Richard L Oei,4 Joanne NG Oude Elberink,2,4 Emmy M Roerdink,5 Marie Louise Schuttelaar,3 Jantina L van der Velde,1,2 Thecla M Brakel,1,6 Anthony EJ Dubois2,5 1Department of General Practice, 2GRIAC Research Institute, 3Department of Dermatology, 4Department of Allergology, 5Department of Pediatric Pulmonology and Pediatric Allergy, University of Groningen, University Medical Center Groningen, 6Teaching Unit, Department of Social Psychology, University of Groningen, Groningen, The Netherlands Background: Management of allergic patients in the population is becoming more difficult because of increases in both complexity and prevalence. Although general practitioners (GPs are expected to play an important role in the care of allergic patients, they often feel ill-equipped for this task. Therefore, the aim of this study was to develop an allergy management support system (AMSS for primary care. Methods: Through literature review, interviewing and testing in secondary and primary care patients, an allergy history questionnaire was constructed by allergists, dermatologists, GPs and researchers based on primary care and specialists’ allergy guidelines and their clinical knowledge. Patterns of AMSS questionnaire responses and specific immunoglobulin E (sIgE-test outcomes were used to identify diagnostic categories and develop corresponding management recommendations. Validity of the AMSS was investigated by comparing specialist (gold standard and AMSS diagnostic categories. Results: The two-page patient-completed AMSS questionnaire consists of 12 (mainly multiple choice questions on symptoms, triggers, severity and medication. Based on the AMSS questionnaires and sIgE-test outcome of 118 patients, approximately 150 diagnostic categories of allergic rhinitis, asthma, atopic dermatitis, anaphylaxis, food allergy, hymenoptera allergy and other

Satellite communication from user to user

Science.gov (United States)

Gern, Manfred

Satellite communication systems which allow a multitude of user-to-user, point-to-point, and multipoint connections, are presented. The bit rates are 64 kbit/sec and multiples, up to 1.92 Mbit/sec. If required, the ground-stations are installed at the customer's site or at suitable locations in order to serve several customers. However, technical requirements for station location have also to be fulfulled, in order to avoid interference with terrestrial radio services. The increasing number of participants to Satellite Multi Service and INTELSAT Business Services imposes the solution of the problem of communication using cheap techniques. The changes of the German Federal Post Office also permit the economic use of satellite radio techniques for short distances.

Experiment In Aeronautical-Mobile/Satellite Communication

Science.gov (United States)

Jedrey, Thomas C.; Lay, Norman E.; Dessouky, Khaled

1992-01-01

Report describes study of performance of digital mobile/satellite communication terminals of advanced design intended for use in ground stations and airplanes in aeronautical-mobile service. Study was collaboration of NASA, Federal Aviation Administration (FAA), Communications Satellite Corp. (COMSAT), and International Maritime Satellite System (INMARSAT).

Monitoring activities of satellite data processing services in real-time with SDDS Live Monitor

Science.gov (United States)

Duc Nguyen, Minh

2017-10-01

This work describes Live Monitor, the monitoring subsystem of SDDS - an automated system for space experiment data processing, storage, and distribution created at SINP MSU. Live Monitor allows operators and developers of satellite data centers to identify errors occurred in data processing quickly and to prevent further consequences caused by the errors. All activities of the whole data processing cycle are illustrated via a web interface in real-time. Notification messages are delivered to responsible people via emails and Telegram messenger service. The flexible monitoring mechanism implemented in Live Monitor allows us to dynamically change and control events being shown on the web interface on our demands. Physicists, whose space weather analysis models are functioning upon satellite data provided by SDDS, can use the developed RESTful API to monitor their own events and deliver customized notification messages by their needs.

High power communication satellites power systems study

International Nuclear Information System (INIS)

Josloff, A.T.; Peterson, J.R.

1994-01-01

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

High power communication satellites power systems study

Science.gov (United States)

Josloff, Allan T.; Peterson, Jerry R.

1995-01-01

This paper discusses a planned study to evaluate the commercial attractiveness of high power communication satellites and assesses the attributes of both conventional photovoltaic and reactor power systems. These high power satellites can 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 can be significant.

Satellite power system in the service of man

Energy Technology Data Exchange (ETDEWEB)

Hyde, F.W.

1981-01-01

The solar power satellite concept is discussed in its various aspects: technical assumptions; unit power output; economic impact; impact on resources; environmental impacts; primary system functions; transmission of energy to earth; reception and conversion to usable energy on earth; space transport; station-keeping and attitude control; fabrication and assembly in space; power beam phase control; satellite maintenance; ancillary functions at rectenna site; and emerging technologies.

Monitoring activities of satellite data processing services in real-time with SDDS Live Monitor

Directory of Open Access Journals (Sweden)

Duc Nguyen Minh

2017-01-01

Full Text Available This work describes Live Monitor, the monitoring subsystem of SDDS – an automated system for space experiment data processing, storage, and distribution created at SINP MSU. Live Monitor allows operators and developers of satellite data centers to identify errors occurred in data processing quickly and to prevent further consequences caused by the errors. All activities of the whole data processing cycle are illustrated via a web interface in real-time. Notification messages are delivered to responsible people via emails and Telegram messenger service. The flexible monitoring mechanism implemented in Live Monitor allows us to dynamically change and control events being shown on the web interface on our demands. Physicists, whose space weather analysis models are functioning upon satellite data provided by SDDS, can use the developed RESTful API to monitor their own events and deliver customized notification messages by their needs.

Satellite Technologies and Services: Implications for International Distance Education.

Science.gov (United States)

Stahmer, Anna

1987-01-01

This examination of international distance education and open university applications of communication satellites at the postsecondary level notes activities in less developed countries (LDCs); presents potential models for cooperation; and describes technical systems for distance education, emphasizing satellite technology and possible problems…

New Generation of Broadcasting Satellite Systems: New Markets and Business Developments

Science.gov (United States)

Perrot, Bruno; Michel, Cyril; Villaret, Stéfanie

2002-01-01

Since the deployment of the first Digital Broadcasting Satellite Systems, European satellite operators and service providers have been faced with the continuously increasing demand for Digital Broadcasting Services. Their success is built on the availability of the MPEG and DVB standards. Undoubtedly, conventional digital television broadcasting is today the `Killer' application. Various service providers already offer multimedia applications through DVB-S systems based upon the `Push' technology. Although these services do not currently represent the core business for broadcasting satellite operators, their percentage is increasing. `Push' technology services include Data Carousel, Webcasting, Turbo Internet, File casting and so on. Such technology can support the implementation of different emerging multimedia services scenarios from Newsgroups, Network collaborative learning, and tele-medicine, to others that may be invented in the near future. The penetration rate of multi-channel television reception is still increasing. Broadcasting satellites benefit both from the development of new, more segmented and sophisticated offers and from the development of Internet services. Satellite is likely to enter these new markets at different levels of the value chain: Even if the satellite has demonstrated its capacity to fully serve the television, combinations with other networks may be necessary to address the new markets: at the consumer premises, Internet-related services will require a return path; at the backbone level, satellite becomes a component of a full telecommunications solution. This article focuses on the European market and proposes:

Advanced Communications Technology Satellite (ACTS) and potential system applications

Science.gov (United States)

Wright, David L.; Balombin, Joseph R.; Sohn, Philip Y.

1990-01-01

A description of the advanced communications technology satellite (ACTS) system is given with special emphasis on the communication characteristics. Potential satellite communications scenarios, including future operational ACTS-like satellite systems, are discussed. The description of the ACTS system updates previously published ACTS system references. Detailed information on items such as experimental ground stations is presented. The potential services can be generically described as voice, video, and data services. The implementation of these services on future operational ACTS-like systems can lead to unique quality, flexibility, and capacity characteristics at lower service costs. The specific service applications that could be supported range from low to high data rates and include both domestic and international applications.

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

Science.gov (United States)

Hoder, Douglas; Bergamo, Marcos

1996-01-01

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

HAPS Gateway Link in the 5850-7075 MHz and Coexistence with Fixed Satellite Service

Directory of Open Access Journals (Sweden)

M. Ahmed

2013-09-01

Full Text Available Gateway link is essential to connect HAPS platform to terrestrial based networks. This crucial link is incorporated in HAPS fixed service spectrum allocation in considerably high frequencies, renders the link for more attenuations by atmospheric gases, and rain effects, especially when the regional climate is not favorable. However, under the agenda item 1.20 of World Radio Conference-2012 (WRC-12 new HAPS allocation in the 5850-7075 MHz band is proposed. Although, spectrum features are incomparably reliable, on the contrary, Fixed Satellite Service (FSS uplink transmissions will have signal levels much higher than those in HAPS systems and have the potential for causing interference at the HAPS gateway receiver. In this article a key aspect of co-channel interference phenomena is investigated to facilitate optimum frequency sharing in the band in question. By proposing mitigation techniques and statistical method this generic prediction model enhances the capability of the HAPS spectrum sharing and provides flexibility in spectrum planning for different fixed services.

TYCHO: Demonstrator and operational satellite mission to Earth-Moon-Libration point EML-4 for communication relay provision as a service

Science.gov (United States)

Hornig, Andreas; Homeister, Maren

2015-03-01

In the current wake of mission plans to the Moon and to Earth-Moon Libration points (EML) by several agencies and organizations, TYCHO identifies the key role of telecommunication provision for the future path of lunar exploration. It demonstrates an interesting extension to existing communication methods to the Moon and beyond by combining innovative technology with a next frontier location and the commercial space communication sector. It is evident that all communication systems will rely on direct communication to Earth ground stations. In case of EML-2 missions around HALO orbits or bases on the far side of the Moon, it has to be extended by communication links via relay stations. The innovative approach is that TYCHO provides this relay communication to those out-of-sight lunar missions as a service. TYCHO will establish a new infrastructure for future missions and even create a new market for add-on relay services. The TMA-0 satellite is TYCHO's first phase and a proposed demonstrator mission to the Earth-Moon Libration point EML-4. It demonstrates relay services needed for automated exploratory and manned missions (Moon bases) on the rim (>90°E and >90°W) and far side surface, to lunar orbits and even to EML-2 halo orbits (satellites and space stations). Its main advantage is the permanent availability of communication coverage. This will provide full access to scientific and telemetry data and furthermore to crucial medical monitoring and safety. The communication subsystem is a platform for conventional communication but also a test-bed for optical communication with high data-rate LASER links to serve the future needs of manned bases and periodic burst data-transfer from lunar poles. The operational TMA-1 satellite is a stand-alone mission integrated into existing space communication networks to provide open communication service to external lunar missions. Therefore the long-time stable libration points EML-4 and -5 are selected to guarantee an

MoMoSat -- Mobile Service for Monitoring with GeoNotes via Satellite

Energy Technology Data Exchange (ETDEWEB)

Niemeyer, Irmgard [Forschungszentrum Juelich (Germany). Programme Group Systems Analysis and Technology Evaluation (STE); Jonas, Karl [Univ. of Applied Science Bonn-Rhein-Sieg, Sankt Augustin (Germany). FhG FOKUS CC SATCom; Horz, Alexander [horz informatik, Sankt Augustin (Germany); Wettschereck, Dietrich; Schmidt, Dirk [DIALOGIS GmbH, Bonn (Germany)

2003-05-01

The MoMoSat service will enable mobile end-users to view, manage, annotate, and communicate mapbased information in the field. The handled information exists of a huge volume of raster (satellite or aerial images) and vector data (i.e. street networks, cadastral maps or points of interest), as well as text-specific geo-referenced textual notes (the so-called 'GeoNotes') and real-time voice. A secure real-time communication between mobile units and the primary data store is an essential task of the MoMoSat service. The basic information is stored in the primary database that is accessible through a virtual private network (VPN) and cached at a server at a base station in order to ensure data availability. The base station may be installed in a car or another mobile vehicle. The two servers will periodically communicate with each other via secure satellite communication in order to check for updates. The base station supplies the relevant GIS data for the mobile units (people or even robots in the field at remote solutions). The communication between the mobile units is based on a peer-to-peer wireless local area network (WLAN) architecture. The mobile units are equipped with mobile computers (i.e. laptop, tablet PC or PDA) combined with a satellite-based positioning system (GPS) that enables them to request the proper geographic data sets from yhe base station's map server. An interactive mapping software shows the actual location on the map and allows the user to navigate (zoom, pan) through the high-resolution map display. The user can switch 'on' or 'off' several thematic layers (i.e. street network or points of interest) on the map. The software also supports collaborative aspects of MoMoSat by offering tools for the management of the GeoNotes that can be visualized by categories. The user can extend the existing GeoNotes with his personnel comments or create new GeoNotes by defining categories, recipients and the level of

Newspaper Uses of Satellite Technology.

Science.gov (United States)

Johns, David

Replacing slower mail service, satellite transmission now gives the newspaper industry a practical and almost spontaneous method for sending all kinds of information to any newspaper across the country. Unlike other communication industries, newspapers did not begin to make widespread use of satellite technology until 1979, when government…

ECOSPACE : a pre-operational satellite system and services for ocean colour monitoring

Science.gov (United States)

Morel, André; Cerutti-Maori, Guy; Morel, Michel

2017-11-01

A permanent monitoring of the oceanic algal biomass (phytoplankton), of its photosynthetic activity, ecological and biogeochemical impact, or of its long-term response to changing physical and climatic conditions, is a crucial goal of scientific programmes (such as JGOFS, GLOBEC, LOICZ), as well as of international observing systems (such as GOOS, GCOS, IGOS). After a decade without ocean colour satellite-borne sensor, several instruments have been, or will be launched. They are increasingly sophisticated in their design and operation. Their complexity results from constraints for multipurpose mission (involving not only ocean, but also land and atmosphere), or from requirements for exploratory research projects and development of new methodologies for improved ocean colour interpretation and "advanced" products. In contrast, the proposed specific ECOSPACE mission is an ocean colour dedicated instrument, with a global monitoring vocation. It relies on known algorithms for accurate atmospheric corrections and aerosol load estimate over open ocean (about 96% of the whole ocean), and known algorithms for a meaningful quantification of the oceanic algal biomass (in terms of Chlorophyll concentration). The coastal zones are observed as well, and their particular features delineated : however, detailed studies that imply high ground resolution and more spectral channels are out of the scope of the present proposal. The ECOSPACE mission represents a feasibility demonstration ; more precisely it is a first step toward the setting up of an operational Satellite System and Services for a future continuous supply of stable, compatible, easy-to-merge ocean colour date products. In essence, such a Service would be similar to those already existing for meteorology and for some oceanic variables (e.g. sea level). Although new approaches to management and implementation over a short time scale are needed, the ECOSPACE project relies essentially on existing scientific and

The method of quick satellite aiming with 3-Steps on the mobile satellite station

Directory of Open Access Journals (Sweden)

Sheng Liang

2017-02-01

Full Text Available The study analyses and concludes the technology of the satellite aiming during real-time broadcast of mobile video.We conclude a method of quick satellite aiming with 3-steps according to practical exercises and users' requirement to meet situation of facts and standardized operation,which can improve efficiency and quality of service.

JPSS Preparations at the Satellite Proving Ground for Marine, Precipitation, and Satellite Analysis

Science.gov (United States)

Folmer, M. J.; Berndt, E.; Clark, J.; Orrison, A.; Kibler, J.; Sienkiewicz, J. M.; Nelson, J. A., Jr.; Goldberg, M.

2016-12-01

The National Oceanic and Atmospheric Administration (NOAA) Satellite Proving Ground (PG) for Marine, Precipitation, and Satellite Analysis (MPS) has been demonstrating and evaluating Suomi National Polar-orbiting Partnership (S-NPP) products along with other polar-orbiting satellite platforms in preparation for the Joint Polar Satellite System - 1 (JPSS-1) launch in March 2017. The first S-NPP imagery was made available to the MPS PG during the evolution of Hurricane Sandy in October 2012 and has since been popular in operations. Since this event the MPS PG Satellite Liaison has been working with forecasters on ways to integrate single-channel and multispectral imagery from the Visible Infrared Imaging Radiometer Suite (VIIRS), the Moderate Resolution Imaging Spectroradiometer (MODIS), and the Advanced Very High Resolution Radiometer (AVHRR)into operations to complement numerical weather prediction and geostationary satellite savvy National Weather Service (NWS) National Centers. Additional unique products have been introduced to operations to address specific forecast challenges, including the Cooperative Institute for Research in the Atmosphere (CIRA) Layered Precipitable Water, the National Environmental Satellite, Data, and Information Service (NESDIS) Snowfall Rate product, NOAA Unique Combined Atmospheric Processing System (NUCAPS) Soundings, ozone products from the Atmospheric Infrared Sounder (AIRS), Cross-track Infrared Sounder/Advanced Technology Microwave Sounder (CrIS/ATMS), and Infrared Atmospheric Sounding Interferometer (IASI). In addition, new satellite domains have been created to provide forecasters at the NWS Ocean Prediction Center and Weather Prediction Center with better quality imagery at high latitudes. This has led to research projects that are addressing forecast challenges such as tropical to extratropical transition and explosive cyclogenesis. This presentation will provide examples of how the MPS PG has been introducing and integrating

Volumetrically-Derived Global Navigation Satellite System Performance Assessment from the Earths Surface through the Terrestrial Service Volume and the Space Service Volume

Science.gov (United States)

Welch, Bryan W.

2016-01-01

NASA is participating in the International Committee on Global Navigation Satellite Systems (GNSS) (ICG)'s efforts towards demonstrating the benefits to the space user from the Earth's surface through the Terrestrial Service Volume (TSV) to the edge of the Space Service Volume (SSV), when a multi-GNSS solution space approach is utilized. The ICG Working Group: Enhancement of GNSS Performance, New Services and Capabilities has started a three phase analysis initiative as an outcome of recommendations at the ICG-10 meeting, in preparation for the ICG-11 meeting. The first phase of that increasing complexity and fidelity analysis initiative was recently expanded to compare nadir-facing and zenith-facing user hemispherical antenna coverage with omnidirectional antenna coverage at different distances of 8,000 km altitude and 36,000 km altitude. This report summarizes the performance using these antenna coverage techniques at distances ranging from 100 km altitude to 36,000 km to be all encompassing, as well as the volumetrically-derived system availability metrics.

The HSBQ Algorithm with Triple-play Services for Broadband Hybrid Satellite Constellation Communication System

Directory of Open Access Journals (Sweden)

Anupon Boriboon

2016-07-01

Full Text Available The HSBQ algorithm is the one of active queue management algorithms, which orders to avoid high packet loss rates and control stable stream queue. That is the problem of calculation of the drop probability for both queue length stability and bandwidth fairness. This paper proposes the HSBQ, which drop the packets before the queues overflow at the gateways, so that the end nodes can respond to the congestion before queue overflow. This algorithm uses the change of the average queue length to adjust the amount by which the mark (or drop probability is changed. Moreover it adjusts the queue weight, which is used to estimate the average queue length, based on the rate. The results show that HSBQ algorithm could maintain control stable stream queue better than group of congestion metric without flow information algorithm as the rate of hybrid satellite network changing dramatically, as well as the presented empiric evidences demonstrate that the use of HSBQ algorithm offers a better quality of service than the traditionally queue control mechanisms used in hybrid satellite network.

An approach to effective UHF (S/L band) data communications for satellite Personal Communication Service (PCS)

Science.gov (United States)

Hayase, Joshua Y.

1995-01-01

Reliable signaling information transfer is fundamental in supporting the needs of data communication PCS via LMS (Land Mobile Service) SSs (satellite systems). The needs of the system designer can be satisfied only through the collection of media information that can be brought to bear on the pertinent design issues. We at ISI hope to continue our dialogue with fading media experts to address the unique data communications needs of PCS via LMS SSs.

Plan of Time Management of Satellite Positioning System using Quasi-zenith Satellite

Science.gov (United States)

Takahashi, Yasuhiro; Fujieda, Miho; Amagai, Jun; Yokota, Shoichiro; Kimura, Kazuhiro; Ito, Hiroyuki; Hama, Shin'ichi; Morikawa, Takao; Kawano, Isao; Kogure, Satoshi

The Quasi-Zenith satellites System (QZSS) is developed as an integrated satellite service system of communication, broadcasting and positioning for mobile users in specified regions of Japan from high elevation angle. Purposes of the satellite positioning system using Quasi-Zenith satellite (QZS) are to complement and augment the GPS. The national institutes concerned have been developing the positioning system using QZS since 2003 and will carry out experiments and researches in three years after the launch. In this system, National Institute of Information and Communications Technology (NICT) is mainly in charge of timing system for the satellite positioning system using QZS, such as onboard hydrogen maser atomic clock and precise time management system of the QZSS. We started to develop the engineering model of the time management system for the QZSS. The time management system for the QZSS will be used to compare time differences between QZS and earth station as well as to compare between three onboard atomic clocks. This paper introduces time management of satellite positioning system using the QZSS.

Advanced mobile satellite communications using COMETS satellite in MM-wave and Ka-band

Science.gov (United States)

Ohmori, Shingo; Isobe, Shunkichi; Takeuchi, Makoto; Naito, Hideyuki

1993-01-01

Early in the 21st century, the demand for personal communications using mobile, hand-held, and VSAT terminals will rapidly increase. In a future system, many different types of services should be provided with one-hop connection. The Communications Research Laboratory (CRL) has studied a future advanced mobile satellite communications system using millimeter wave and Ka band. In 1990, CRL started the Communications and Broadcasting Engineering Test Satellite (COMETS) project. The satellite has been developed in conjunction with NASDA and will be launched in 1997. This paper describes the COMETS payload configuration and the experimental system for the advanced mobile communications mission.

After 10 years of service, NOAA retires GOES-12 satellite

Science.gov (United States)

NOAA HOME WEATHER OCEANS FISHERIES CHARTING SATELLITES CLIMATE RESEARCH COASTS CAREERS National oceans. In addition to GOES, NOAA also operates the polar operational environmental satellite (POES spacecraft. NOAA's mission is to understand and predict changes in the Earth's environment, from the depths

Simobiz-Simulation Tool to Study the Impact of Small Satellites in Mobile Market

Science.gov (United States)

Burlacu, M.-M.; Kohlenberg, J.; Prathaban, M.

2008-08-01

Interest in small satellites is growing fast world- wide. Businesses, governments, universities and other organizations around the world are starting their own small satellite programs. The surveys conducted by the space agencies and universities shows a promising increase in the use of small satellites for commercial applications. More number of operators offers or plans to offer mobile phone services by satellite. With the help of cost effective small satellite, mobile operators can be able to provide the services cheaper. Hence, it is always interesting to study the effect of low cost small satellite over the mobile market. In this article, we present SmartSim (Small Satellites Mobile Market Simulator) - the new module of Simobiz business simulation game, in which we have implemented two operators, a normal satellite operator and a nanosatellite operator, with specific terminals and services. Our main focus in this work is to understand the future market of small satellite in mobile telecommunication network.

A series on optimizing satellite systems. I - Restoring interruptions of communications sattelite service: Logistical and cost comparisons of mature and newly operational systems

Science.gov (United States)

Snow, Marcellus S.

1989-09-01

A mathematical model is presented of costs and operational factors involved in provision for service interruptions of both a mature and typically large incumbent satellite system and of a smaller, more recently operational system. The equation expresses the required launch frequency for the new system as a function of the launch spacing of the mature system; the time disparity between the inauguration of the two systems; and the rate of capacity depreciation. In addition, a technique is presented to compare the relative extent to which the discounted costs of the new system exceed those of the mature system in furnishing the same effective capacity in orbit, and thus the same service liability, at a given point in time. It is determined that a mature incumbent communications satellite system, having more capacity in orbit, will on balance have a lower probability of service interruption than a newer, smaller system.

Reservation centre of Telecom I satellite French Telecommunication network offers a new service of switched digital circuit

Science.gov (United States)

Felix, J.

The management center and new circuit switching services offered by the French Telecom I network are described. Attention is focused on business services. The satellite has a 125 Mbit/sec capability distributed over 5 frequency bands, yielding the equivalent of 1800 channels. Data are transmitted in digitized bursts with TDMA techniques. Besides the management center, Telecom I interfaces with 310 local network antennas with access managed by the center through a reservation service and protocol assignment. The center logs and supervises alarms and network events, monitors traffic, logs taxation charges and manages the man-machine dialog for TDMA and terrestrial operations. Time slots are arranged in terms of minimal 10 min segments. The reservations can be directly accessed by up to 1000 terminals. All traffic is handled on a call-by-call basis.

Satellite failures revisited

Science.gov (United States)

Balcerak, Ernie

2012-12-01

In January 1994, the two geostationary satellites known as Anik-E1 and Anik-E2, operated by Telesat Canada, failed one after the other within 9 hours, leaving many northern Canadian communities without television and data services. The outage, which shut down much of the country's broadcast television for hours and cost Telesat Canada more than $15 million, generated significant media attention. Lam et al. used publicly available records to revisit the event; they looked at failure details, media coverage, recovery effort, and cost. They also used satellite and ground data to determine the precise causes of those satellite failures. The researchers traced the entire space weather event from conditions on the Sun through the interplanetary medium to the particle environment in geostationary orbit.

The Necessity of ASEAN Competition Law: Rethinking

Directory of Open Access Journals (Sweden)

Udin Silalahi

2017-12-01

Full Text Available As outlined in the AEC Blueprint, all ASEAN member states (AMSs will endeavour to introduce competition policy by 2015. At present 7 (seven AMSs, namely: Indonesia, Singapore, Malaysia, Thailand, Vietnam, Philippines, Myanmar have the national competition laws to supervise anti-competitive conduct in the domestic market. But the question is what if happened unfair competition between ASEAN member states, due to the agreement or businesses activities by business actors that harm competition? ASEAN has an ASEAN Regional Guidelines on Competition Policy (ARGCP that developed by ASEAN Experts Group on Competition (AEGC as framework for member states to develop its own competition law or policy and as a guideline in measuring that directly affect the behaviour of enterprises and the structure of industry and markets. Regional Guideline is just to help AMSs in increasing of awareness of important policy, not to sustain the competition among ASEAN member countries. Until now there is no ASEAN Competition Law and Institution to oversee competition among ASEAN member countries. In this era, ASEAN economic integration it is a certainty that anti-competitive among AMSs will happen.

Integration of Satellite and Terrestrial Systems in Future Multimedia Communications

OpenAIRE

Evans, Barry; Werner, Markus; Lutz, Erich; Bousquet, Michel; Corazza, Giovanni E; Maral, Gerard; Rumeau, Robert; Ferro, Erina

2005-01-01

In this article we examine the role of satellite communications in future telecommunication networks and service provision. Lessons from the past indicate that satellites are successful as a result of their wide area coverage or speed to market for new services. Niche areas such as coverage of air and sea will persist, but for land masses convergence of fixed, mobile, and broadcasting will dictate that the only way forward for satellites is in an integrated format with terrestrial systems. We...

Liste des personnes citées1

OpenAIRE

2013-01-01

AAHOA Asian American Hotel Owner Association ABCD American Born Confused Desi AFMI American Association of Muslims from India AIC American Islamic College AIM Association of Indian Muslims AMASES American Muslim Alliance Social and Family Services AMC American Muslim Council AMM American Muslim Mission AMSE Association of Muslim Scientists and Engineers AMSS American Muslim Social Scientists BCCI Bank of Credit and Commerce International BJP Bharatiya Janata Party CAIR Council on American-Isl...

Proposed systems configurations for a satellite based ISDN

Science.gov (United States)

Capece, M.; Pavesi, B.; Tozzi, P.; Galligan, K. P.

This paper summarizes concepts developed during a study for the ESA in which the evolution of ISDN capability and the impact in the satellite land mobile area are examined. Following the progressive steps of the expected ISDN implementation and the potential market penetration, a space based system capable of satisfying particular user services classes has been investigated. The approach used is to establish a comparison between the requirements of potential mobile users and the services already envisaged by ISDN, identifying the service subclasses that might be adopted in a mobile environment through a satellite system. Two system alternatives, with different ISDN compatibility, have been identified. The first option allows a partial compatibility, by providing the central stations of the earth segment with suitable interface units. The second option permits a full integration, operating on the satellite on-board capabilities.

A Generalized Visual Aid System for Teleoperation Applied to Satellite Servicing

Directory of Open Access Journals (Sweden)

Guoliang Zhang

2014-02-01

Full Text Available This paper presents the latest results of a newly developed visual aid system for direct teleoperation. This method is extended to visual control to make an efficient teleoperation system by combining direct teleoperation and automatic control. On the one hand, an operator can conduct direct teleoperation with 3D graphic prediction simulation established by the VR technique. In order to remove inconsistencies between the virtual and real environments, a practical model-matching method is investigated. On the other hand, to realize real-time visual servoing control, a particular object recognition and pose estimation algorithm based on polygonal approximation is investigated to ensure a low computational cost for image processing. To avoid undesired forces involved in contact operation, 3D visual servoing incorporating a compliant control based on impedance control is developed. Finally, in a representative laboratory environment, a typical satellite servicing experiment is carried out based on this combined system. Experimental results demonstrate the feasibility and the effectiveness of the proposed method.

Single Tree Vegetation Depth Estimation Tool for Satellite Services Link Design

Directory of Open Access Journals (Sweden)

Z. Hasirci

2016-04-01

Full Text Available Attenuation caused by tree shadowing is an important factor for describing the propagation channel of satellite services. Thus, vegetation effects should be determined by experimental studies or empirical formulations. In this study, tree types in the Black Sea Region of Turkey are classified based on their geometrical shapes into four groups such as conic, ellipsoid, spherical and hemispherical. The variations of the vegetation depth according to different tree shapes are calculated with ray tracing method. It is showed that different geometrical shapes have different vegetation depths even if they have same foliage volume for different elevation angles. The proposed method is validated with the related literature in terms of average single tree attenuation. On the other hand, due to decrease system requirements (speed, memory usage etc. of ray tracing method, an artificial neural network is proposed as an alternative. A graphical user interface is created for the above processes in MATLAB environment named vegetation depth estimation tool (VdET.

Mission studies on constellation of LEO satellites with remote-sensing and communication payloads

Science.gov (United States)

Chen, Chia-Ray; Hwang, Feng-Tai; Hsueh, Chuang-Wei

2017-09-01

Revisiting time and global coverage are two major requirements for most of the remote sensing satellites. Constellation of satellites can get the benefit of short revisit time and global coverage. Typically, remote sensing satellites prefer to choose Sun Synchronous Orbit (SSO) because of fixed revisiting time and Sun beta angle. The system design and mission operation will be simple and straightforward. However, if we focus on providing remote sensing and store-and-forward communication services for low latitude countries, Sun Synchronous Orbit will not be the best choice because we need more satellites to cover the communication service gap in low latitude region. Sometimes the design drivers for remote sensing payloads are conflicted with the communication payloads. For example, lower orbit altitude is better for remote sensing payload performance, but the communication service zone will be smaller and we need more satellites to provide all time communication service. The current studies focus on how to provide remote sensing and communication services for low latitude countries. A cost effective approach for the mission, i.e. constellation of microsatellites, will be evaluated in this paper.

New applications for the EUTELTRACS service

Science.gov (United States)

Colcy, Jean-Noel; Vanderbrouck, Laurent

1995-01-01

The EUTELTRACS two-way Mobile Satellite Messaging and Automatic Satellite Position Reporting (ASPR) service is Europe's first commercially operated Mobile Satellite Service. It was introduced by the European Telecommunications Satellite Organization (EUTELSAT) for commercial service in 1991. The system is based on a centralized network architecture organized around a single hub station operated by EUTELSAT. Initially the system was designed with a close user group architecture enabling a mobile user to communicate exclusively with its own headquarters. This paper describes the new applications (design and tests prior to their introduction into service) especially developed for the European market and particularly the Double Hop Services opening the system to authorized external entities. In addition, the European Commission (EC) pilot demonstrations in which the EUTELTRACS system is involved are described.

Addressing and Presenting Quality of Satellite Data via Web-Based Services

Science.gov (United States)

Leptoukh, Gregory; Lynnes, C.; Ahmad, S.; Fox, P.; Zednik, S.; West, P.

2011-01-01

With the recent attention to climate change and proliferation of remote-sensing data utilization, climate model and various environmental monitoring and protection applications have begun to increasingly rely on satellite measurements. Research application users seek good quality satellite data, with uncertainties and biases provided for each data point. However, different communities address remote sensing quality issues rather inconsistently and differently. We describe our attempt to systematically characterize, capture, and provision quality and uncertainty information as it applies to the NASA MODIS Aerosol Optical Depth data product. In particular, we note the semantic differences in quality/bias/uncertainty at the pixel, granule, product, and record levels. We outline various factors contributing to uncertainty or error budget; errors. Web-based science analysis and processing tools allow users to access, analyze, and generate visualizations of data while alleviating users from having directly managing complex data processing operations. These tools provide value by streamlining the data analysis process, but usually shield users from details of the data processing steps, algorithm assumptions, caveats, etc. Correct interpretation of the final analysis requires user understanding of how data has been generated and processed and what potential biases, anomalies, or errors may have been introduced. By providing services that leverage data lineage provenance and domain-expertise, expert systems can be built to aid the user in understanding data sources, processing, and the suitability for use of products generated by the tools. We describe our experiences developing a semantic, provenance-aware, expert-knowledge advisory system applied to NASA Giovanni web-based Earth science data analysis tool as part of the ESTO AIST-funded Multi-sensor Data Synergy Advisor project.

Standard Test Method for Mechanical Hydrogen Embrittlement Evaluation of Plating/Coating Processes and Service Environments

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 This test method describes mechanical test methods and defines acceptance criteria for coating and plating processes that can cause hydrogen embrittlement in steels. Subsequent exposure to chemicals encountered in service environments, such as fluids, cleaning treatments or maintenance chemicals that come in contact with the plated/coated or bare surface of the steel, can also be evaluated. 1.2 This test method is not intended to measure the relative susceptibility of different steels. The relative susceptibility of different materials to hydrogen embrittlement may be determined in accordance with Test Method F1459 and Test Method F1624. 1.3 This test method specifies the use of air melted AISI E4340 steel per SAE AMS-S-5000 (formerly MIL-S-5000) heat treated to 260 – 280 ksi (pounds per square inch x 1000) as the baseline. This combination of alloy and heat treat level has been used for many years and a large database has been accumulated in the aerospace industry on its specific response to exposure...

The design of an ultra-low sidelobe offset-fed 1.22m antenna for use in the broadcasting satellite service

Science.gov (United States)

Janky, J. M.

1981-01-01

A feed design and reflector geometry were determined for an ultra low sidelobe offset fed 1.22 meter antenna suitable for use in the 12 GHz broadcasting satellite service. Arbitrary constraints used to evaluate the relative merits of the feed horns and range of f/D geometries are: minimum efficiency of 55 percent, -30 dB first sidelobe level (relative to on axis gain), a 0 dBi plateau beyond the near in sidelobe region, and a Chebyshev polynomial based envelope (borrowed from filter theory) for the region from the -3 dB beamwidth points to the 0 dBi plateau region. This envelope is extremely stringent but the results of this research effort indicate that two steps of corrugated feed and a cluster array of small 1 lambda horns do meet the constraints. A set of performance specifications and a mechanical design suitable for a consumer oriented market in the broadcasting satellite service was developed. Costs for production quantities of 10,000 units/yr. are estimated to be around $150.

On-board processing for telecommunications satellites

Science.gov (United States)

Nuspl, P. P.; Dong, G.

1991-01-01

In this decade, communications satellite systems will probably face dramatic challenges from alternative transmission means. To balance and overcome such competition, and to prepare for new requirements, INTELSAT has developed several on-board processing techniques, including Satellite-Switched TDMA (SS-TDMA), Satellite-Switched FDMA (SS-FDMA), several Modulators/Demodulators (Modem), a Multicarrier Multiplexer and Demodulator MCDD), an International Business Service (IBS)/Intermediate Data Rate (IDR) BaseBand Processor (BBP), etc. Some proof-of-concept hardware and software were developed, and tested recently in the INTELSAT Technical Laboratories. These techniques and some test results are discussed.

ARTES: the future of satellite telecommunication

Science.gov (United States)

González-Blázquez, Angel; Detain, Dominique

2005-08-01

Throughout its 30-year existence, ESA has played a key role by providing telecommunications infrastructures that have allowed the in-orbit validation, qualification and demonstration of equipment, technology and services. In the past, this has been achieved through the provision of dedicated satellites like OTS, Marecs, Olympus and Artemis, as well as by the implementation of piggy-back payloads on other ESA or commercial satellites. Today, due to the importance of satellite telecommunications, ESA continues to support this sector mainly through its ARTES - Advanced Research in Telecommunications - Programme.

Proceedings of the Fifth International Mobile Satellite Conference 1997

Science.gov (United States)

Jedrey, T. (Compiler); Rigley, J. (Compiler); Anderson, Louise (Editor)

1997-01-01

Satellite-based mobile communications systems provide voice and data communications to users over a vast geographic area. The users may communicate via mobile or hand-held terminals, which may also provide access to terrestrial communications services. While previous International Mobile Satellite Conferences have concentrated on technical advances and the increasing worldwide commercial activities, this conference focuses on the next generation of mobile satellite services. The approximately 80 papers included here cover sessions in the following areas: networking and protocols; code division multiple access technologies; demand, economics and technology issues; current and planned systems; propagation; terminal technology; modulation and coding advances; spacecraft technology; advanced systems; and applications and experiments.

ESA personal communications and digital audio broadcasting systems based on non-geostationary satellites

Science.gov (United States)

Logalbo, P.; Benedicto, J.; Viola, R.

1993-01-01

Personal Communications and Digital Audio Broadcasting are two new services that the European Space Agency (ESA) is investigating for future European and Global Mobile Satellite systems. ESA is active in promoting these services in their various mission options including non-geostationary and geostationary satellite systems. A Medium Altitude Global Satellite System (MAGSS) for global personal communications at L and S-band, and a Multiregional Highly inclined Elliptical Orbit (M-HEO) system for multiregional digital audio broadcasting at L-band are described. Both systems are being investigated by ESA in the context of future programs, such as Archimedes, which are intended to demonstrate the new services and to develop the technology for future non-geostationary mobile communication and broadcasting satellites.

Satellite communications - Intelsat and global patterns

Science.gov (United States)

Astrain, S.

1983-10-01

The global pattern of mankind's population growth is examined, taking into account the exponential increase in population which began only in the 17th century. As world population has grown, trade has increased, and transportation and communications have become vitally important. A revolution in global communications was initiated when Intelsat launched the first international communications satellite, 'Early Bird', in April 1965. Since April 1965, a tremendous development in global communications by means of satellites has taken place. The Intelsat VI satellite will have a capacity of 36,000 telephone circuits plus 2 TV channels, while the capacity of Early Bird was only 240 telephone circuits. Today, Intelsat is truly an international organization which includes 108 member countries. Attention is given to the particular importance of the Intelsat services to the developing countries, the exploration of new technologies and system concepts, and the extension of services to those portions of the global village which have remained electronically isolated.

Recent Korean R&D in Satellite Communications

Science.gov (United States)

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

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

Satellite ATM Networks: Architectures and Guidelines Developed

Science.gov (United States)

vonDeak, Thomas C.; Yegendu, Ferit

1999-01-01

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

Integration between terrestrial-based and satellite-based land mobile communications systems

Science.gov (United States)

Arcidiancono, Antonio

1990-01-01

A survey is given of several approaches to improving the performance and marketability of mobile satellite systems (MSS). The provision of voice/data services in the future regional European Land Mobile Satellite System (LMSS), network integration between the Digital Cellular Mobile System (GSM) and LMSS, the identification of critical areas for the implementation of integrated GSM/LMSS areas, space segment scenarios, LMSS for digital trunked private mobile radio (PMR) services, and code division multiple access (CDMA) techniques for a terrestrial/satellite system are covered.

Comprehensive Comparisons of Satellite Data, Signals, and Measurements between the BeiDou Navigation Satellite System and the Global Positioning System †

Science.gov (United States)

Jan, Shau-Shiun; Tao, An-Lin

2016-01-01

The Chinese BeiDou navigation satellite system (BDS) aims to provide global positioning service by 2020. The combined use of BDS and Global Positioning System (GPS) is proposed to provide navigation service with more stringent requirements. Actual satellite data, signals and measurements were collected for more than one month to analyze the positioning service qualities from both BDS and GPS. In addition to the conversions of coordinate and timing system, five data quality analysis (DQA) methods, three signal quality analysis (SQA) methods, and four measurement quality analysis (MQA) methods are proposed in this paper to improve the integrated positioning performance of BDS and GPS. As shown in the experiment results, issues related to BDS and GPS are resolved by the above proposed quality analysis methods. Thus, the anomalies in satellite data, signals and measurements can be detected by following the suggested resolutions to enhance the positioning performance of the combined use of BDS and GPS in the Asia Pacific region. PMID:27187403

Building technological capability within satellite programs in developing countries

Science.gov (United States)

Wood, Danielle; Weigel, Annalisa

2011-12-01

This paper explores the process of building technological capability in government-led satellite programs within developing countries. The key message is that these satellite programs can learn useful lessons from literature in the international development community. These lessons are relevant to emerging satellite programs that leverage international partnerships in order to establish local capability to design, build and operate satellites. Countries with such programs include Algeria, Nigeria, Turkey, Malaysia and the United Arab Emirates. The paper first provides background knowledge about space activity in developing countries, and then explores the nuances of the lessons coming from the international development literature. Developing countries are concerned with satellite technology because satellites provide useful services in the areas of earth observation, communication, navigation and science. Most developing countries access satellite services through indirect means such as sharing data with foreign organizations. More countries, however, are seeking opportunities to develop satellite technology locally. There are objective, technically driven motivations for developing countries to invest in satellite technology, despite rich debate on this topic. The paper provides a framework to understand technical motivations for investment in satellite services, hardware, expertise and infrastructure in both short and long term. If a country decides to pursue such investments they face a common set of strategic decisions at the levels of their satellite program, their national context and their international relationships. Analysis of past projects shows that countries have chosen diverse strategies to address these strategic decisions and grow in technological capability. What is similar about the historical examples is that many countries choose to leverage international partnerships as part of their growth process. There are also historical examples from

Commercial satellite broadcasting for Europe

Science.gov (United States)

Forrest, J. R.

1988-12-01

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.

Mobility management in satellite networks

Science.gov (United States)

Johanson, Gary A.

1995-01-01

This paper addresses the methods used or proposed for use in multi-beam and/or multi-satellite networks designed to provide Mobile Satellite Services (MSS). Specific topics include beam crossover in the North American Mobile Satellite (MSAT) system as well as registration and live call hand-off for a multi-regional geosynchronous (GEO) satellite based system and a global coverage Low Earth Orbiting (LEO) system. In the MSAT system, the individual satellite beams cover very large geographic areas so the need for live call hand-off was not anticipated. This paper discusses the methods used to keep track of the beam location of the users so that incoming call announcements or other messages may be directed to them. Proposed new GEO systems with large numbers of beams will provide much smaller geographic coverage in individual beams and thus the need arises to keep track of the user's location as well as to provide live call hand-off as the user traverses from beam to beam. This situation also occurs in proposed LEO systems where the problems are worsened by the need for satellite to satellite hand-off as well as beam to beam hand-off within a single satellite. The paper discusses methods to accomplish these handoffs and proposes system architectures to address the various hand-off scenarios.

Time-Zone-Pattern Satellite Broadcasting Antenna

Science.gov (United States)

Galindo, Victor; Rahmat-Samii, Yahya; Imbriale, William A.; Cohen, Herb; Cagnon, Ronald R.

1988-01-01

Direct-broadcast satellite antenna designs provide contoured beams to match four time zones in 48 contiguous states and spot beams for Alaska, Hawaii, and Puerto Rico presented in 29-page report. Includes descriptions of procedures used to arrive at optimized designs. Arrangements, amplitudes, and phases of antenna feeds presented in tables. Gain contours shown graphically. Additional tables of performance data given for cities in service area of Eastern satellite.

Satellites for U.S. education - Needs, opportunities and systems.

Science.gov (United States)

Morgan, R. P.; Singh, J. P.; Anderson, B. D.; Greenberg, E.

1972-01-01

This paper presents results of a continuing interdisciplinary study of the potential applications of Fixed- and Broadcast-Satellites for educational information transfer in the United States for the period 1975-1985. The status of U.S. education is examined and needs, trends and issues are discussed. The existing educational telecommunications infrastructure is examined and opportunities for satellite services are defined. Potential uses include networking of educational institutions and service centers for delivery of public and instructional television, computer-aided instruction, computing and information resources to regions and groups not now adequately served. Systems alternatives and some of the organizational and economic issues inherent in the deployment of an educational satellite system are discussed.-

A demand assignment control in international business satellite communications network

Science.gov (United States)

Nohara, Mitsuo; Takeuchi, Yoshio; Takahata, Fumio; Hirata, Yasuo

An experimental system is being developed for use in an international business satellite (IBS) communications network based on demand-assignment (DA) and TDMA techniques. This paper discusses its system design, in particular from the viewpoints of a network configuration, a DA control, and a satellite channel-assignment algorithm. A satellite channel configuration is also presented along with a tradeoff study on transmission rate, HPA output power, satellite resource efficiency, service quality, and so on.

A design of 30/20 GHz flight communications experiment for NASA. [satellite and earth segments for high data rate commercial service

Science.gov (United States)

Kawamoto, Y.

1982-01-01

The objective of the 30/20 GHz Flight Experiment System is to develop the required technology and to experiment with the communication technique for an operational communication satellite system. The system uses polarization, spatial, and frequency isolations to maximize the spectrum utilization. The key spacecraft technologies required for the concept are the scan beam antenna, the baseband processor, the IF switch matrix, TWTA, SSPA, and LNA. The spacecraft communication payload information will be telemetered and monitored closely so that these technologies and performances can be verified. Two types of services, a trunk service and a customer premise service, are demonstrated in the system. Many experiments associated with these services, such as synchronization, demand assignment, link control, and network control will be performed to provide important information on the operational aspect of the system.

Protocols for second-generation business satellites systems

Science.gov (United States)

Evans, B. G.; Coakley, F. P.; El Amin, M. H. M.

The paper discusses the nature and mix of traffic in business satellite systems and describes the limitations on the protocol imposed by the differing impairments of speech, video, and data. A simple TDMA system protocol is presented which meets the requirements of mixed-service operation. The efficiency of the protocol together with implications for allocation, scheduling and synchronisation are discussed. Future-generation satellites will probably use on-board processing. Some initial work on protocols that make use of on-board processing and the implications for satellite and earth-station equipment are presented.

Challenges in Visualizing Satellite Level 2 Atmospheric Data with GIS approach

Science.gov (United States)

Wei, J. C.; Yang, W.; Zhao, P.; Pham, L.; Meyer, D. J.

2017-12-01

Satellite data products are important for a wide variety of applications that can bring far-reaching benefits to the science community and the broader society. These benefits can best be achieved if the satellite data are well utilized and interpreted. Unfortunately, this is not always the case, despite the abundance and relative maturity of numerous satellite data products provided by NASA and other organizations. One way to help users better understand the satellite data is to provide data along with `Images', including accurate pixel coverage area delineation, and science team recommended quality screening for individual geophysical parameters. However, there are challenges of visualizing remote sensed non-gridded products: (1) different geodetics of space-borne instruments (2) data often arranged in "along-track" and "across-track" axes (3) spatially and temporally continuous data chunked into granule files: data for a portion (or all) of a satellite orbit (4) no general rule of resampling or interpolations to a grid (5) geophysical retrieval only based on pixel center location without shape information. In this presentation, we will unravel a new Goddard Earth Sciences Data and Information Services Center (GES DISC) Level 2 (L2) visualization on-demand service. The service's front end provides various visualization and data accessing capabilities, such as overlay and swipe of multiply variables and subset and download of data in different formats. The backend of the service consists of Open Geospatial Consortium (OGC) standard-compliant Web Mapping Service (WMS) and Web Coverage Service. The infrastructure allows inclusion of outside data sources served in OGC compliant protocols and allows other interoperable clients, such as ArcGIS clients, to connect to our L2 WCS/WMS.

Challenges in Obtaining and Visualizing Satellite Level 2 Data in GIS

Science.gov (United States)

Wei, Jennifer C.; Yang, Wenli; Zhao, Peisheng; Pham, Long; Meyer, David J.

2017-01-01

Satellite data products are important for a wide variety of applications that can bring far-reaching benefits to the science community and the broader society. These benefits can best be achieved if the satellite data are well utilized and interpreted. Unfortunately, this is not always the case, despite the abundance and relative maturity of numerous satellite data products provided by NASA and other organizations. One way to help users better understand the satellite data is to provide data along with Images, including accurate pixel coverage area delineation, and science team recommended quality screening for individual geophysical parameters. However, there are challenges of visualizing remote sensed non-gridded products: (1) different geodetics of space-borne instruments (2) data often arranged in a long-track� and a cross-track� axes (3) spatially and temporally continuous data chunked into granule files: data for a portion (or all) of a satellite orbit (4) no general rule of resampling or interpolations to a grid (5) geophysical retrieval only based on pixel center location without shape information. In this presentation, we will unravel a new Goddard Earth Sciences Data and Information Services Center (GES DISC) Level 2 (L2) visualization on-demand service. The service's front end provides various visualization and data accessing capabilities, such as overlay and swipe of multiply variables and subset and download of data in different formats. The backend of the service consists of Open Geospatial Consortium (OGC) standard-compliant Web Mapping Service (WMS) and Web Coverage Service. The infrastructure allows inclusion of outside data sources served in OGC compliant protocols and allows other interoperable clients, such as ArcGIS clients, to connect to our L2 WCS/WMS.

SOVCAN STAR: An international satellite system

Science.gov (United States)

Skatchkov, Valery A.

SOVCAN STAR is a Russian-Canadian cooperative venture company formed to manufacture, test, launch and operate a Ku-band satellite system. Drawing on the more than twenty years communications satellite experience of the founding companies, the SOVCAN STAR satellites are being designed to be competitive and cost effective. They will be equipped with 24 transponders and four steerable antennas. The design allows the operators to switch individual transponders between the various antenna coverage beams. These satellites will offer a high degree of operational flexibility and performance. The SOVCAN STAR strategy is to develop a network of satellites in parallel with the growth and evolution of the traffic requirements. Such an approach minimizes the technical, schedule and program risks while at the same time significantly reduces the financial exposure. The first SOVCAN STAR satellite will be commissioned in 1996 and operated at 14 deg W. The beams will be aligned to North America and Europe offering International service between Canada, the Eastern U.S.A., Europe, Russia and the Western C.I.S. Republics. The second SOVCAN STAR satellite will be commissioned a year later and operated at 145 deg E. This satellite will cover the Western Pacific Ocean, Eastern Asia and Australasia.

Increasing cellular coverage within integrated terrestrial/satellite mobile networks

Science.gov (United States)

Castro, Jonathan P.

1995-01-01

When applying the hierarchical cellular concept, the satellite acts as giant umbrella cell covering a region with some terrestrial cells. If a mobile terminal traversing the region arrives to the border-line or limits of a regular cellular ground service, network transition occurs and the satellite system continues the mobile coverage. To adequately assess the boundaries of service of a mobile satellite system an a cellular network within an integrated environment, this paper provides an optimized scheme to predict when a network transition may be necessary. Under the assumption of a classified propagation phenomenon and Lognormal shadowing, the study applies an analytical approach to estimate the location of a mobile terminal based on a reception of the signal strength emitted by a base station.

Ground Simulation of an Autonomous Satellite Rendezvous and Tracking System Using Dual Robotic Systems

Science.gov (United States)

Trube, Matthew J.; Hyslop, Andrew M.; Carignan, Craig R.; Easley, Joseph W.

2012-01-01

A hardware-in-the-loop ground system was developed for simulating a robotic servicer spacecraft tracking a target satellite at short range. A relative navigation sensor package "Argon" is mounted on the end-effector of a Fanuc 430 manipulator, which functions as the base platform of the robotic spacecraft servicer. Machine vision algorithms estimate the pose of the target spacecraft, mounted on a Rotopod R-2000 platform, relay the solution to a simulation of the servicer spacecraft running in "Freespace", which performs guidance, navigation and control functions, integrates dynamics, and issues motion commands to a Fanuc platform controller so that it tracks the simulated servicer spacecraft. Results will be reviewed for several satellite motion scenarios at different ranges. Key words: robotics, satellite, servicing, guidance, navigation, tracking, control, docking.

An overview of reference user services during the ATDRSS (Advanced Tracking and Data Relay Satellite System) era

Science.gov (United States)

Weinberg, Aaron

1989-01-01

The Tracking and Data Relay Satellite System (TDRSS) is an integral part of the overall NASA Space Network (SN) that will continue to evolve into the 1990's. Projections for the first decade of the 21st century indicate the need for an SN evolution that must accommodate growth int he LEO user population and must further support the introduction of new/improved user services. A central ingredient of this evolution is an Advanced TDRSS (ATDRSS) follow-on to the current TDRSS that must initiate operations by the late 1990's in a manner that permits an orderly transition from the TDRSS to the ATDRSS era. An SN/ATDRSS architectural and operational concept that will satisfy the above goals is being developed. To this date, an SN/ATDRSS baseline concept was established that provides users with an end-to-end data transport (ENDAT) service. An expanded description of the baseline ENDAT concept, from the user perspective, is provided with special emphasis on the TDRSS/ATDRSS evolution. A high-level description of the end-to-end system that identifies the role of ATDRSS is presented; also included is a description of the baseline ATDRSS architecture and its relationship with the TDRSS 1996 baseline. Other key features of the ENDAT service are then expanded upon, including the multiple grades of service, and the RF telecommunications/tracking services to be available. The ATDRSS service options are described.

COSMOS Launch Services

Science.gov (United States)

Kalnins, Indulis

2002-01-01

COSMOS-3M is a two stage launcher with liquid propellant rocket engines. Since 1960's COSMOS has launched satellites of up to 1.500kg in both circular low Earth and elliptical orbits with high inclination. The direct SSO ascent is available from Plesetsk launch site. The very high number of 759 launches and the achieved success rate of 97,4% makes this space transportation system one of the most reliable and successful launchers in the world. The German small satellite company OHB System co-operates since 1994 with the COSMOS manufacturer POLYOT, Omsk, in Russia. They have created the joint venture COSMOS International and successfully launched five German and Italian satellites in 1999 and 2000. The next commercial launches are contracted for 2002 and 2003. In 2005 -2007 COSMOS will be also used for the new German reconnaissance satellite launches. This paper provides an overview of COSMOS-3M launcher: its heritage and performance, examples of scientific and commercial primary and piggyback payload launches, the launch service organization and international cooperation. The COSMOS launch service business strategy main points are depicted. The current and future position of COSMOS in the worldwide market of launch services is outlined.

How to Get Data from NOAA Environmental Satellites: An Overview of Operations, Products, Access and Archive

Science.gov (United States)

Donoho, N.; Graumann, A.; McNamara, D. P.

2015-12-01

In this presentation we will highlight access and availability of NOAA satellite data for near real time (NRT) and retrospective product users. The presentation includes an overview of the current fleet of NOAA satellites and methods of data distribution and access to hundreds of imagery and products offered by the Environmental Satellite Processing Center (ESPC) and the Comprehensive Large Array-data Stewardship System (CLASS). In particular, emphasis on the various levels of services for current and past observations will be presented. The National Environmental Satellite, Data, and Information Service (NESDIS) is dedicated to providing timely access to global environmental data from satellites and other sources. In special cases, users are authorized direct access to NESDIS data distribution systems for environmental satellite data and products. Other means of access include publicly available distribution services such as the Global Telecommunication System (GTS), NOAA satellite direct broadcast services and various NOAA websites and ftp servers, including CLASS. CLASS is NOAA's information technology system designed to support long-term, secure preservation and standards-based access to environmental data collections and information. The National Centers for Environmental Information (NCEI) is responsible for the ingest, quality control, stewardship, archival and access to data and science information. This work will also show the latest technology improvements, enterprise approach and future plans for distribution of exponentially increasing data volumes from future NOAA missions. A primer on access to NOAA operational satellite products and services is available at http://www.ospo.noaa.gov/Organization/About/access.html. Access to post-operational satellite data and assorted products is available at http://www.class.noaa.gov

NOAA budget would boost satellite funding but cut some key areas

Science.gov (United States)

Showstack, Randy

2012-03-01

The White House's proposed fiscal year (FY) 2013 budget for the National Oceanic and Atmospheric Administration (NOAA), announced on 13 February, looks favorable at first glance. The administration's request calls for $5.1 billion, an increase of $153 million (3.1%) above the FY 2012 estimated budget. However, the increase for NOAA satellites is $163 million, which means that other areas within the agency would be slated for decreased funding, including programs within the National Ocean Service (NOS), National Marine Fisheries Service (NMFS), National Weather Service (NWS), and some NOAA education programs. The proposed overall budget for the agency “reflects the overarching importance of weather satellites to public safety, to national security, and to the economy,” NOAA director Jane Lubchenco said at a 16 February briefing, noting that difficult choices were made regarding the budget. “Due to significant resources required for our weather satellites and the economic conditions in the country, other parts of our budget have been reduced, in some cases quite significantly,” she said. She added that the imperative to fund both the Joint Polar Satellite System (JPSS) and geostationary satellites in FY 2013 “imposes serious constraints on the rest of NOAA's budget.”

The large satellite program of ESA and its relevance for broadcast missions

Science.gov (United States)

Fromm, H.-H.; Herdan, B. L.

1981-03-01

In an investigation of the market prospects and payload requirements of future communications satellites, it was concluded that during the next 15 years many space missions will demand larger satellite platforms than those currently available. These platforms will be needed in connection with direct-broadcasting satellites, satellites required to enhance capacities in the case of traditional services, and satellites employed to introduce new types of satellite-based communications operating with small terminals. Most of the larger satellites would require the Ariane III capability, corresponding to about 1400 kg satellite mass in geostationary orbit. Attention is given to L-SAT platform capabilities and broadcast payload requirements, taking into account a European direct-broadcast satellite and Canadian direct-broadcast missions.

Cloud-based Web Services for Near-Real-Time Web access to NPP Satellite Imagery and other Data

Science.gov (United States)

Evans, J. D.; Valente, E. G.

2010-12-01

We are building a scalable, cloud computing-based infrastructure for Web access to near-real-time data products synthesized from the U.S. National Polar-Orbiting Environmental Satellite System (NPOESS) Preparatory Project (NPP) and other geospatial and meteorological data. Given recent and ongoing changes in the the NPP and NPOESS programs (now Joint Polar Satellite System), the need for timely delivery of NPP data is urgent. We propose an alternative to a traditional, centralized ground segment, using distributed Direct Broadcast facilities linked to industry-standard Web services by a streamlined processing chain running in a scalable cloud computing environment. Our processing chain, currently implemented on Amazon.com's Elastic Compute Cloud (EC2), retrieves raw data from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) and synthesizes data products such as Sea-Surface Temperature, Vegetation Indices, etc. The cloud computing approach lets us grow and shrink computing resources to meet large and rapid fluctuations (twice daily) in both end-user demand and data availability from polar-orbiting sensors. Early prototypes have delivered various data products to end-users with latencies between 6 and 32 minutes. We have begun to replicate machine instances in the cloud, so as to reduce latency and maintain near-real time data access regardless of increased data input rates or user demand -- all at quite moderate monthly costs. Our service-based approach (in which users invoke software processes on a Web-accessible server) facilitates access into datasets of arbitrary size and resolution, and allows users to request and receive tailored and composite (e.g., false-color multiband) products on demand. To facilitate broad impact and adoption of our technology, we have emphasized open, industry-standard software interfaces and open source software. Through our work, we envision the widespread establishment of similar, derived, or interoperable systems for

Texas Telecommunication Satellite Demonstration Project. Planning Effort for Application of Communication Satellites in Education.

Science.gov (United States)

Education Service Center Region 4, Houston, TX.

The primary goal of the Texas Telecommunication Satellite Demonstration consortium is to install, operate, and evaluate a comprehensive communication service delivery system which would provide the citizens of Texas with greater opportunity for equal access to education and information. The four major objectives of the demonstration are (1) to…

Communications Satellite Receiver Systems for Public Schools: A Technical Primer.

Science.gov (United States)

Texas Education Agency, Austin.

Designed to aid school districts contemplating use of some of the telecommunications services now available by satellite, this document contains information on home satellite receiving dishes (Television Receive-Only--TVROs), which can receive radio signals carrying television, sound, and data. This information includes: some factors involved in…

A Case Study of Three Satellite Technology Demonstration School Sites.

Science.gov (United States)

Law, Gordon

The Satellite Technology Demonstration (STD) represented a cooperative and complex effort involving federal, regional, state and local interests and demonstrated the feasibility of media distribution by communication satellite of social services for rural audiences. As part of a comprehensive evaluation plan, the summative data base was augmented…

47 CFR 25.217 - Default service rules.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Default service rules. 25.217 Section 25.217 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS... licenses to operate a satellite system in a frequency band granted after a domestic frequency allocation...

Study of LEO-SAT microwave link for broad-band mobile satellite communication system

Science.gov (United States)

Fujise, Masayuki; Chujo, Wataru; Chiba, Isamu; Furuhama, Yoji; Kawabata, Kazuaki; Konishi, Yoshihiko

1993-01-01

In the field of mobile satellite communications, a system based on low-earth-orbit satellites (LEO-SAT's) such as the Iridium system has been proposed. The LEO-SAT system is able to offer mobile telecommunication services in high-latitude areas. Rain degradation, fading and shadowing are also expected to be decreased when the system is operated at a high elevation angle. Furthermore, the propagation delay generated in the LEO-SAT system is less pronounced than that in the geostationary orbit satellite (GEO-SAT) system and, in voice services, the effect of the delay is almost negligible. We proposed a concept of a broad-band mobile satellite communication system with LEO-SAT's and Optical ISL. In that system, a fixed L-band (1.6/1.5 GHz) multibeam is used to offer narrow band service to the mobile terminals in the entire area covered by a LEO-SAT and steerable Ka-band (30/20 GHz) spot beams are used for the wide band service. In this paper, we present results of a study of LEO-SAT microwave link between a satellite and a mobile terminal for a broad-band mobile satellite communication system. First, the results of link budget calculations are presented and the antennas mounted on satellites are shown. For a future mobile antenna technology, we also show digital beamforming (DBF) techniques. DBF, together with modulation and/or demodulation, is becoming a key technique for mobile antennas with advanced functions such as antenna pattern calibration, correction, and radio interference suppression. In this paper, efficient DBF techniques for transmitting and receiving are presented. Furthermore, an adaptive array antenna system suitable for this LEO-SAT is presented.

Satellite Communications Using Commercial Protocols

Science.gov (United States)

Ivancic, William D.; Griner, James H.; Dimond, Robert; Frantz, Brian D.; Kachmar, Brian; Shell, Dan

2000-01-01

NASA Glenn Research Center has been working with industry, academia, and other government agencies in assessing commercial communications protocols for satellite and space-based applications. In addition, NASA Glenn has been developing and advocating new satellite-friendly modifications to existing communications protocol standards. This paper summarizes recent research into the applicability of various commercial standard protocols for use over satellite and space- based communications networks as well as expectations for future protocol development. It serves as a reference point from which the detailed work can be readily accessed. Areas that will be addressed include asynchronous-transfer-mode quality of service; completed and ongoing work of the Internet Engineering Task Force; data-link-layer protocol development for unidirectional link routing; and protocols for aeronautical applications, including mobile Internet protocol routing for wireless/mobile hosts and the aeronautical telecommunications network protocol.

47 CFR 25.401 - Satellite DARS applications subject to competitive bidding.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Satellite DARS applications subject to competitive bidding. 25.401 Section 25.401 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Competitive Bidding Procedures for DARS § 25.401...

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

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Qualifications of fixed-satellite space station licensees. 25.140 Section 25.140 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses Space Stations § 25.140 Qualifications...

Fire Monitoring - The use of medium resolution satellites (AVHRR, MODIS, TET) for long time series processing and the implementation in User Driven Applications and Services

Science.gov (United States)

Fuchs, E.-M.; Stein, E.; Strunz, G.; Strobl, C.; Frey, C.

2015-04-01

This paper introduces fire monitoring works of two different projects, namely TIMELINE (TIMe Series Processing of Medium Resolution Earth Observation Data assessing Long -Term Dynamics In our Natural Environment) and PHAROS (Project on a Multi-Hazard Open Platform for Satellite Based Downstream Services). It describes the evolution from algorithm development from in applied research to the implementation in user driven applications and systems. Concerning TIMELINE, the focus of the work lies on hot spot detection. A detailed description of the choice of a suitable algorithm (round robin approach) will be given. Moreover, strengths and weaknesses of the AVHRR sensor for hot spot detection, a literature review, the study areas and the selected approach will be highlighted. The evaluation showed that the contextual algorithm performed best, and will therefore be used for final implementation. Concerning the PHAROS project, the key aspect is on the use of satellite-based information to provide valuable support to all phases of disaster management. The project focuses on developing a pre-operational sustainable service platform that integrates space-based EO (Earth Observation), terrestrial sensors and communication and navigation assets to enhance the availability of services and products following a multi-hazard approach.

MARAD maritime experiments using the NASA ATS-6 satellite

Science.gov (United States)

Brandel, D. L.; Kaminsky, Y.

1975-01-01

The objectives of the MARAD maritime experiments (conducted in the L-band fan beam mode) using the ATS-6 satellite are detailed. They include the following: (1) to evaluate the economic benefits of fleet operators through the use of satellite communications, (2) to evaluate performance criteria for shipboard terminal equipment needed to establish various grades of fleet operations services using commercial satellite systems, (3) to determine the effects of signal propagation, ship radio frequency noise, and ship antenna pointing on the maritime communications and navigation channel, and (4) to evaluate various modems for the transmission and reception of voice, data and position location signals via satellite systems.

Satellites

International Nuclear Information System (INIS)

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

1986-01-01

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

Experimental study on the precise orbit determination of the BeiDou navigation satellite system.

Science.gov (United States)

He, Lina; Ge, Maorong; Wang, Jiexian; Wickert, Jens; Schuh, Harald

2013-03-01

The regional service of the Chinese BeiDou satellite navigation system is now in operation with a constellation including five Geostationary Earth Orbit satellites (GEO), five Inclined Geosynchronous Orbit (IGSO) satellites and four Medium Earth Orbit (MEO) satellites. Besides the standard positioning service with positioning accuracy of about 10 m, both precise relative positioning and precise point positioning are already demonstrated. As is well known, precise orbit and clock determination is essential in enhancing precise positioning services. To improve the satellite orbits of the BeiDou regional system, we concentrate on the impact of the tracking geometry and the involvement of MEOs, and on the effect of integer ambiguity resolution as well. About seven weeks of data collected at the BeiDou Experimental Test Service (BETS) network is employed in this experimental study. Several tracking scenarios are defined, various processing schemata are designed and carried out; and then, the estimates are compared and analyzed in detail. The results show that GEO orbits, especially the along-track component, can be significantly improved by extending the tracking network in China along longitude direction, whereas IGSOs gain more improvement if the tracking network extends in latitude. The involvement of MEOs and ambiguity-fixing also make the orbits better.

Generation of Digital Surface Models from satellite photogrammetry: the DSM-OPT service of the ESA Geohazards Exploitation Platform (GEP)

Science.gov (United States)

Stumpf, André; Michéa, David; Malet, Jean-Philippe

2017-04-01

The continuously increasing fleet of agile stereo-capable very-high resolution (VHR) optical satellites has facilitated the acquisition of multi-view images of the earth surface. Theoretical revisit times have been reduced to less than one day and the highest spatial resolution which is commercially available amounts now to 30 cm/pixel. Digital Surface Models (DSM) and point clouds computed from such satellite stereo-acquisitions can provide valuable input for studies in geomorphology, tectonics, glaciology, hydrology and urban remote sensing The photogrammetric processing, however, still requires significant expertise, computational resources and costly commercial software. To enable a large Earth Science community (researcher and end-users) to process easily and rapidly VHR multi-view images, the work targets the implementation of a fully automatic satellite-photogrammetry pipeline (i.e DSM-OPT) on the ESA Geohazards Exploitation Platform (GEP). The implemented pipeline is based on the open-source photogrammetry library MicMac [1] and is designed for distributed processing on a cloud-based infrastructure. The service can be employed in pre-defined processing modes (i.e. urban, plain, hilly, and mountainous environments) or in an advanced processing mode (i.e. in which expert-users have the possibility to adapt the processing parameters to their specific applications). Four representative use cases are presented to illustrate the accuracy of the resulting surface models and ortho-images as well as the overall processing time. These use cases consisted of the construction of surface models from series of Pléiades images for four applications: urban analysis (Strasbourg, France), landslide detection in mountainous environments (South French Alps), co-seismic deformation in mountain environments (Central Italy earthquake sequence of 2016) and fault recognition for paleo-tectonic analysis (North-East India). Comparisons of the satellite-derived topography to airborne

An FDMA system concept for 30/20 GHz high capacity domestic satellite service

Science.gov (United States)

Berk, G.; Jean, P. N.; Rotholz, E.; White, B. E.

1982-01-01

The paper summarizes a feasibility study of a multibeam FDMA satellite system operating in the 30/20 GHz band. The system must accommodate a very high volume of traffic within the restrictions of a 5 kW solar cell array and a 2.5 GHz bandwidth. Multibeam satellite operation reduces the DC power demand and allows reuse of the available bandwidth. Interferences among the beams are brought to acceptable levels by appropriate frequency assignments. A transponder design is presented; it is greatly simplified by the application of a regional concept. System analysis shows that MSK modulation is appropriate for a high-capacity system because it conserves the frequency spectrum. Rain attenuation, a serious problem in this frequency band, is combatted with sufficient power margins and with coding. Link budgets, cost analysis, and weight and power calculations are also discussed. A satellite-routed FDMA system compares favorably in performance and cost with a satellite-switched TDMA system.

Modular approach for satellite communication ground terminals

Science.gov (United States)

Gould, G. R.

1984-01-01

The trend in satellite communications is toward completely digital, time division multiple access (TDMA) systems with uplink and downlink data rates dictated by the type of service offered. Trunking terminals will operate in the 550 MBPS (megabit per second) region uplink and downlink, whereas customer premise service (CPS) terminals will operate in the 25 to 10 MBPS region uplink and in the 200 MBPS region downlink. Additional criteria for the ground terminals will be to maintain clock sychronization with the system and burst time integrity to within a matter of nanoseconds, to process required order-fire information, to provide adaptive data scrambing, and to compensate for variations in the user input output data rates, and for changes in range in the satellite communications links resulting from satellite perturbations in orbit. To achieve the required adaptability of a ground terminal to the above mentioned variables, programmable building blocks can be developed that will meet all of these requirements. To maintain system synchronization, i.e., all bursted data arriving at the satellite within assigned TDMA windows, ground terminal transmit data rates and burst timing must be maintained within tight tolerances. With a programmable synchronizer as the heart of the terminal timing generation, variable data rates and burst timing tolerances are achievable. In essence, the unit inputs microprocessor generated timing words and outputs discrete timing pulses.

Digital, Satellite-Based Aeronautical Communication

Science.gov (United States)

Davarian, F.

1989-01-01

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

Satellite communications: possibilities and problems

International Nuclear Information System (INIS)

Hine, M.

1986-01-01

Communication links via satellites are becoming available in Europe, both as part of the development of the telephone system and as special services aimed at data traffic. They offer the possibility of speeds between 50 kb/s and 2 Mb/s, without the problems and long term commitments of long distance land lines. Such links are provided by the PTT's as circuits which can be booked for variable periods, and have error rates which can be very low and well controlled. Problems in networking can arise from the satellite delay, particularly if errors occur in the local connections, and from the leased circuit and tariff philosophies of the PTT's. (Auth.)

Improvement of Ka-band satellite link availability for real-time IP-based video contribution

Directory of Open Access Journals (Sweden)

G. Berretta

2017-09-01

Full Text Available New High Throughput Satellite (HTS systems allow high throughput IP uplinks/contribution at Ka-band frequencies for relatively lower costs when compared to broadcasting satellite uplinks at Ku band. This technology offers an advantage for live video contribution from remote areas, where the terrestrial infrastructure may not be adequate. On the other hand, the Ka-band is more subject to impairments due to rain or bad weather. This paper addresses the target system specification and provides an optimized approach for the transmission of IP-based video flows through HTS commercial services operating at Ka-band frequencies. In particular, the focus of this study is on the service requirements and the propagation analysis that provide a reference architecture to improve the overall link availability. The approach proposed herein leads to the introduction of a new concept of live service contribution using pairs of small satellite antennas and cheap satellite terminals.

A Survey of Congestion Control Techniques and Data Link Protocols in Satellite Networks

OpenAIRE

Fahmy, Sonia; Jain, Raj; Lu, Fang; Kalyanaraman, Shivkumar

1998-01-01

Satellite communication systems are the means of realizing a global broadband integrated services digital network. Due to the statistical nature of the integrated services traffic, the resulting rate fluctuations and burstiness render congestion control a complicated, yet indispensable function. The long propagation delay of the earth-satellite link further imposes severe demands and constraints on the congestion control schemes, as well as the media access control techniques and retransmissi...

The next generation of Palapa satellite (Palapa-C)

Science.gov (United States)

Setiawan, Bambang

The Indonesian Palapa Communication Satellite System was established in Aug. 1976 when the first satellite of Palapa A series (Palapa A1) began operation. The system is owned and operated by PT. Telekomunikasi Indonesia (Telkom), which is a state owned company. The purpose of the system was to unify the telecommunications of the nation. Many years of operation have shown that satellite technology is the best solution for improving telecommunications in Indonesia. The system was started with 2 (two) satellites, each with 12 transponders (for a total of 24), and 40 earth stations. Now the system has 3 (three) satellites, each with 24 transponders (for a total of 72 transponders), and thousands of earth stations. The services have been extended to satisfy the requirements of the region as well as the original objectives. The use of satellite transponders in the region is increasing rapidly. In the next ten years, opportunities in the satellite communications business will become even more attractive. The next generation Palapa-C will incorporate improvements in capacity, quality, and coverage. The new frequency bands (ku- and Extended-C Band) will be used to meet the new transponder capacity requirements.

European Telecommunications Satellite II (EUTELSAT II)

Science.gov (United States)

Laemmel, G.; Brittinger, P.

1991-01-01

EUTELSAT II is a regional public telecommunications system for Europe. The services which will be provided are telephone and television. The satellites will be placed at a geostationary orbit within the arcs of 6 degrees east to 19 degrees east or 26 degrees to 36 degrees east. The designed lifetime is 7 years. After separation of the satellites from the launch vehicles, telemetry, telecommand, and ranging will be performed within the S-band frequencies. After positioning of the satellite at its final geostationary orbit, the Ku-band telecommunication equipment will be activated. From this time on, all satellite control operations will be performed in Ku-band. The Deep Space Network (DSN) will support the transfer and drift orbit mission phases. The coverage will consist of the 26-m antennas at Goldstone and Canberra as prime support for the transfer and drift orbits. Maximum support will consist of a 7-day period, plus 14 days of contingency support. Information is given in tabular form for DSN support, frequency assignments, telemetry, command, and tracking support responsibility.

Overview of NASA's In Space Robotic Servicing

Science.gov (United States)

Reed, Benjamin B.

2015-01-01

The panel discussion will start with a presentation of the work of the Satellite Servicing Capabilities Office (SSCO), a team responsible for the overall management, coordination, and implementation of satellite servicing technologies and capabilities for NASA. Born from the team that executed the five Hubble servicing missions, SSCO is now maturing a core set of technologies that support both servicing goals and NASA's exploration and science objectives, including: autonomous rendezvous and docking systems; dexterous robotics; high-speed, fault-tolerant computing; advanced robotic tools, and propellant transfer systems. SSCOs proposed Restore-L mission, under development since 2009, is rapidly advancing the core capabilities the fledgling satellite-servicing industry needs to jumpstart a new national industry. Restore-L is also providing key technologies and core expertise to the Asteroid Redirect Robotic Mission (ARRM), with SSCO serving as the capture module lead for the ARRM effort. Reed will present a brief overview of SSCOs history, capabilities and technologies.

National Space Science Data Center and World Data Center A for Rockets and Satellites - Ionospheric data holdings and services

Science.gov (United States)

Bilitza, D.; King, J. H.

1988-01-01

The activities and services of the National Space Science data Center (NSSDC) and the World Data Center A for Rockets and Satellites (WDC-A-R and S) are described with special emphasis on ionospheric physics. The present catalog/archive system is explained and future developments are indicated. In addition to the basic data acquisition, archiving, and dissemination functions, ongoing activities include the Central Online Data Directory (CODD), the Coordinated Data Analysis Workshopps (CDAW), the Space Physics Analysis Network (SPAN), advanced data management systems (CD/DIS, NCDS, PLDS), and publication of the NSSDC News, the SPACEWARN Bulletin, and several NSSD reports.

Optical burst switching based satellite backbone network

Science.gov (United States)

Li, Tingting; Guo, Hongxiang; Wang, Cen; Wu, Jian

2018-02-01

We propose a novel time slot based optical burst switching (OBS) architecture for GEO/LEO based satellite backbone network. This architecture can provide high speed data transmission rate and high switching capacity . Furthermore, we design the control plane of this optical satellite backbone network. The software defined network (SDN) and network slice (NS) technologies are introduced. Under the properly designed control mechanism, this backbone network is flexible to support various services with diverse transmission requirements. Additionally, the LEO access and handoff management in this network is also discussed.

Use of Openly Available Satellite Images for Remote Sensing Education

Science.gov (United States)

Wang, C.-K.

2011-09-01

With the advent of Google Earth, Google Maps, and Microsoft Bing Maps, high resolution satellite imagery are becoming more easily accessible than ever. It have been the case that the college students may already have wealth experiences with the high resolution satellite imagery by using these software and web services prior to any formal remote sensing education. It is obvious that the remote sensing education should be adjusted to the fact that the audience are already the customers of remote sensing products (through the use of the above mentioned services). This paper reports the use of openly available satellite imagery in an introductory-level remote sensing course in the Department of Geomatics of National Cheng Kung University as a term project. From the experience learned from the fall of 2009 and 2010, it shows that this term project has effectively aroused the students' enthusiastic toward Remote Sensing.

Network design consideration of a satellite-based mobile communications system

Science.gov (United States)

Yan, T.-Y.

1986-01-01

Technical considerations for the Mobile Satellite Experiment (MSAT-X), the ground segment testbed for the low-cost spectral efficient satellite-based mobile communications technologies being developed for the 1990's, are discussed. The Network Management Center contains a flexible resource sharing algorithm, the Demand Assigned Multiple Access scheme, which partitions the satellite transponder bandwidth among voice, data, and request channels. Satellite use of multiple UHF beams permits frequency reuse. The backhaul communications and the Telemetry, Tracking and Control traffic are provided through a single full-coverage SHF beam. Mobile Terminals communicate with the satellite using UHF. All communications including SHF-SHF between Base Stations and/or Gateways, are routed through the satellite. Because MSAT-X is an experimental network, higher level network protocols (which are service-specific) will be developed only to test the operation of the lowest three levels, the physical, data link, and network layers.

A geostationary satellite system for mobile multimedia applications using portable, aeronautical and mobile terminals

Science.gov (United States)

Losquadro, G.; Luglio, M.; Vatalaro, F.

1997-01-01

A geostationary satellite system for mobile multimedia services via portable, aeronautical and mobile terminals was developed within the framework of the Advanced Communications Technology Service (ACTS) programs. The architecture of the system developed under the 'satellite extremely high frequency communications for multimedia mobile services (SECOMS)/ACTS broadband aeronautical terminal experiment' (ABATE) project is presented. The system will be composed of a Ka band system component, and an extremely high frequency band component. The major characteristics of the space segment, the ground control station and the portable, aeronautical and mobile user terminals are outlined.

Korea Earth Observation Satellite Program

Science.gov (United States)

Baek, Myung-Jin; Kim, Zeen-Chul

via Korea Aerospace Research Institute (KARI) as the prime contractor in the area of Korea earth observation satellite program to enhance Korea's space program development capability. In this paper, Korea's on-going and future earth observation satellite programs are introduced: KOMPSAT- 1 (Korea Multi Purpose Satellite-1), KOMPSAT-2 and Communication, Broadcasting and Meteorological Satellite (CBMS) program. KOMPSAT-1 satellite successfully launched in December 1999 with Taurus launch vehicle. Since launch, KOMPSAT-1 is downlinking images of Korea Peninsular every day. Until now, KOMPSAT-1 has been operated more than 2 and half years without any major hardware malfunction for the mission operation. KOMPSAT-1 payload has 6.6m panchromatic spatial resolution at 685 km on-orbit and the spacecraft bus had NASA TOMS-EP (Total Ozone Mapping Spectrometer-Earth Probe) spacecraft bus heritage designed and built by TRW, U.S.A.KOMPSAT-1 program was international co-development program between KARI and TRW funded by Korean Government. be launched in 2004. Main mission objective is to provide geo-information products based on the multi-spectral high resolution sensor called Multi-Spectral Camera (MSC) which will provide 1m panchromatic and 4m multi-spectral high resolution images. ELOP of Israel is the prime contractor of the MSC payload system and KARI is the total system prime contractor including spacecraft bus development and ground segment. KARI also has the contract with Astrium of Europe for the purpose of technical consultation and hardware procurement. Based on the experience throughout KOMPSAT-1 and KOMPSAT-2 space system development, Korea is expecting to establish the infrastructure of developing satellite system. Currently, KOMPSAT-2 program is in the critical design stage. are scheduled to launch in 2008 and in 2014, respectively. The mission of CBMS consists of two areas. One is of space technology test for the communications mission, and the other is of a real

Cyber security with radio frequency interferences mitigation study for satellite systems

Science.gov (United States)

Wang, Gang; Wei, Sixiao; Chen, Genshe; Tian, Xin; Shen, Dan; Pham, Khanh; Nguyen, Tien M.; Blasch, Erik

2016-05-01

Satellite systems including the Global Navigation Satellite System (GNSS) and the satellite communications (SATCOM) system provide great convenience and utility to human life including emergency response, wide area efficient communications, and effective transportation. Elements of satellite systems incorporate technologies such as navigation with the global positioning system (GPS), satellite digital video broadcasting, and information transmission with a very small aperture terminal (VSAT), etc. The satellite systems importance is growing in prominence with end users' requirement for globally high data rate transmissions; the cost reduction of launching satellites; development of smaller sized satellites including cubesat, nanosat, picosat, and femtosat; and integrating internet services with satellite networks. However, with the promising benefits, challenges remain to fully develop secure and robust satellite systems with pervasive computing and communications. In this paper, we investigate both cyber security and radio frequency (RF) interferences mitigation for satellite systems, and demonstrate that they are not isolated. The action space for both cyber security and RF interferences are firstly summarized for satellite systems, based on which the mitigation schemes for both cyber security and RF interferences are given. A multi-layered satellite systems structure is provided with cross-layer design considering multi-path routing and channel coding, to provide great security and diversity gains for secure and robust satellite systems.

Worldwide satellite communications for the energy utility industry. Final report

International Nuclear Information System (INIS)

Skelton, R.L.

1998-07-01

Recent and future generations of low earth orbiting (LEO) satellites are promising new possibilities for using space communications to achieve operational improvements and business expansion in energy supply and delivery industries. The ability to reach remote locations with relatively inexpensive devices and infrastructure is a unique property of satellites. Applications include remote monitoring and control of distributed resources and emergency and personal communication. Satellite systems are emerging as a significant opportunity for investment minded utilities. Over a dozen groups are planning to launch a total of 1200 LEOs in the period from 1996 to 2006, at a probable cost of over $20 Billion. This large number of systems can provide a worldwide mix of narrow band and wideband services including data, voice, video and Internet access. This paper examines the two primary factors which have limited applications in the energy industry: cost and propagation delay. The former has so far limited the technology to fixed communications with a few important sites such as remote substations. The latter has rendered the technology unsuitable for applications where critical protection mechanisms are involved. These constraints are effectively countered by the emerging LEO systems. Big LEOs will be used for voice service, little LEOs will be the systems of choice for most utility data applications. The author concludes that there are good technical and business reasons to reconsider future satellite communications as an option for meeting certain strategic business objectives in power system management and customer oriented information services

Satellite end of life constraints: Technical and organisational solutions

Science.gov (United States)

Cabrières, Bernard; Alby, Fernand; Cazaux, Christian

2012-04-01

Since 1974 with the radiocommunication satellite Symphony1, CNES launched and operated 11 GEO and 20 LEO satellites. During those 36 years, both flight segment and ground segment dramatically evolved and operational organisations and techniques equally improved. At the present time, CNES operates 1 GEO satellite and 17 LEO satellites with not much more people and costs than in 1986 when its first Satellite Operation Direction in Toulouse was only in charge of Telecom1A, Telecom1B and Spot1. This fantastic technical evolution combined with the huge increase of services to citizens and governments given by Space systems was unfortunately also associated with an enormous growth of space pollution by debris of all sizes. From the beginning, CNES was a major actor of the international effort to promote regulations in order to try to reduce or at least control this problematic situation. Internally, CNES, not only set up an operational on-call service to deal with collision risks, but decided to do its best to apply the new guidelines to the end of life of satellites under its responsibility even for those developed and launched a very long time ago. For instance, that was the case in 2009 for the reorbitation of the GEO satellite Telecom 2C (launched in 1995) and for the deorbitation of the LEO satellite Spot2 (launched in 1990). In addition, CNES prepares procedures to be able to be as exemplary as possible for its other spacecrafts whose end of life approaches. The constraints and challenges to face in order to cope with these new requirements are multiple: choice of final orbit, realistic calculation of re-entry duration, estimation of residual propellant, electric passivation, management of explosion risks… All these studies and operational experience gained will be helpful for the new role of CNES, which recently became in charge of controlling space operators in the frame of the new French space law on space operations.

The Future of Satellite Communications. Resource Management and the Needs of Nations.

Science.gov (United States)

Hinchman, Walter R.; Dunn, D. A.

Recent events suggest that Intelsat (the 68-nation International Telecommunications Satellite Consortium) will coordinate a number of domestic and regional systems that provide satellite communications services, some of which will be maintained by Intelsat and some of which will be independent. This report addresses the problems of conflict in…

Broadband and scalable mobile satellite communication system for future access networks

Science.gov (United States)

Ohata, Kohei; Kobayashi, Kiyoshi; Nakahira, Katsuya; Ueba, Masazumi

2005-07-01

Due to the recent market trends, NTT has begun research into next generation satellite communication systems, such as broadband and scalable mobile communication systems. One service application objective is to provide broadband Internet access for transportation systems, temporal broadband access networks and telemetries to remote areas. While these are niche markets the total amount of capacity should be significant. We set a 1-Gb/s total transmission capacity as our goal. Our key concern is the system cost, which means that the system should be unified system with diversified services and not tailored for each application. As satellites account for a large portion of the total system cost, we set the target satellite size as a small, one-ton class dry mass with a 2-kW class payload power. In addition to the payload power and weight, the mobile satellite's frequency band is extremely limited. Therefore, we need to develop innovative technologies that will reduce the weight and maximize spectrum and power efficiency. Another challenge is the need for the system to handle up to 50 dB and a wide data rate range of other applications. This paper describes the key communication system technologies; the frequency reuse strategy, multiplexing scheme, resource allocation scheme, and QoS management algorithm to ensure excellent spectrum efficiency and support a variety of services and quality requirements in the mobile environment.

Interactive access to LP DAAC satellite data archives through a combination of open-source and custom middleware web services

Science.gov (United States)

Davis, Brian N.; Werpy, Jason; Friesz, Aaron M.; Impecoven, Kevin; Quenzer, Robert; Maiersperger, Tom; Meyer, David J.

2015-01-01

Current methods of searching for and retrieving data from satellite land remote sensing archives do not allow for interactive information extraction. Instead, Earth science data users are required to download files over low-bandwidth networks to local workstations and process data before science questions can be addressed. New methods of extracting information from data archives need to become more interactive to meet user demands for deriving increasingly complex information from rapidly expanding archives. Moving the tools required for processing data to computer systems of data providers, and away from systems of the data consumer, can improve turnaround times for data processing workflows. The implementation of middleware services was used to provide interactive access to archive data. The goal of this middleware services development is to enable Earth science data users to access remote sensing archives for immediate answers to science questions instead of links to large volumes of data to download and process. Exposing data and metadata to web-based services enables machine-driven queries and data interaction. Also, product quality information can be integrated to enable additional filtering and sub-setting. Only the reduced content required to complete an analysis is then transferred to the user.

Development and validation of satellite-based estimates of surface visibility

Science.gov (United States)

Brunner, J.; Pierce, R. B.; Lenzen, A.

2016-02-01

A satellite-based surface visibility retrieval has been developed using Moderate Resolution Imaging Spectroradiometer (MODIS) measurements as a proxy for Advanced Baseline Imager (ABI) data from the next generation of Geostationary Operational Environmental Satellites (GOES-R). The retrieval uses a multiple linear regression approach to relate satellite aerosol optical depth, fog/low cloud probability and thickness retrievals, and meteorological variables from numerical weather prediction forecasts to National Weather Service Automated Surface Observing System (ASOS) surface visibility measurements. Validation using independent ASOS measurements shows that the GOES-R ABI surface visibility retrieval (V) has an overall success rate of 64.5 % for classifying clear (V ≥ 30 km), moderate (10 km ≤ V United States Environmental Protection Agency (EPA) and National Park Service (NPS) Interagency Monitoring of Protected Visual Environments (IMPROVE) network and provide useful information to the regional planning offices responsible for developing mitigation strategies required under the EPA's Regional Haze Rule, particularly during regional haze events associated with smoke from wildfires.

Development and validation of satellite based estimates of surface visibility

Science.gov (United States)

Brunner, J.; Pierce, R. B.; Lenzen, A.

2015-10-01

A satellite based surface visibility retrieval has been developed using Moderate Resolution Imaging Spectroradiometer (MODIS) measurements as a proxy for Advanced Baseline Imager (ABI) data from the next generation of Geostationary Operational Environmental Satellites (GOES-R). The retrieval uses a multiple linear regression approach to relate satellite aerosol optical depth, fog/low cloud probability and thickness retrievals, and meteorological variables from numerical weather prediction forecasts to National Weather Service Automated Surface Observing System (ASOS) surface visibility measurements. Validation using independent ASOS measurements shows that the GOES-R ABI surface visibility retrieval (V) has an overall success rate of 64.5% for classifying Clear (V ≥ 30 km), Moderate (10 km ≤ V United States Environmental Protection Agency (EPA) and National Park Service (NPS) Interagency Monitoring of Protected Visual Environments (IMPROVE) network, and provide useful information to the regional planning offices responsible for developing mitigation strategies required under the EPA's Regional Haze Rule, particularly during regional haze events associated with smoke from wildfires.

How Satellites Have Contributed to Building a Weather Ready Nation

Science.gov (United States)

Lapenta, W.

2017-12-01

NOAA's primary mission since its inception has been to reduce the loss of life and property, as well as disruptions from, high impact weather and water-related events. In recent years, significant societal losses resulting even from well forecast extreme events have shifted attention from the forecast alone toward ensuring societal response is equal to the risks that exist for communities, businesses and the public. The responses relate to decisions ranging from coastal communities planning years in advance to mitigate impacts from rising sea level, to immediate lifesaving decisions such as a family seeking adequate shelter during a tornado warning. NOAA is committed to building a "Weather-Ready Nation" where communities are prepared for and respond appropriately to these events. The Weather-Ready Nation (WRN) strategic priority is building community resilience in the face of increasing vulnerability to extreme weather, water, climate and environmental threats. To build a Weather-Ready Nation, NOAA is enhancing Impact-Based Decision Support Services (IDSS), transitioning science and technology advances into forecast operations, applying social science research to improve the communication and usefulness of information, and expanding its dissemination efforts to achieve far-reaching readiness, responsiveness and resilience. These four components of Weather-Ready Nation are helping ensure NOAA data, products and services are fully utilized to minimize societal impacts from extreme events. Satellite data and satellite products have been important elements of the national Weather Service (NWS) operations for more than 40 years. When one examines the uses of satellite data specific to the internal forecast and warning operations of NWS, two main applications are evident. The first is the use of satellite data in numerical weather prediction models; the second is the use of satellite imagery and derived products for mesoscale and short-range weather warning and

Satellite Image Classification of Building Damages Using Airborne and Satellite Image Samples in a Deep Learning Approach

Science.gov (United States)

Duarte, D.; Nex, F.; Kerle, N.; Vosselman, G.

2018-05-01

The localization and detailed assessment of damaged buildings after a disastrous event is of utmost importance to guide response operations, recovery tasks or for insurance purposes. Several remote sensing platforms and sensors are currently used for the manual detection of building damages. However, there is an overall interest in the use of automated methods to perform this task, regardless of the used platform. Owing to its synoptic coverage and predictable availability, satellite imagery is currently used as input for the identification of building damages by the International Charter, as well as the Copernicus Emergency Management Service for the production of damage grading and reference maps. Recently proposed methods to perform image classification of building damages rely on convolutional neural networks (CNN). These are usually trained with only satellite image samples in a binary classification problem, however the number of samples derived from these images is often limited, affecting the quality of the classification results. The use of up/down-sampling image samples during the training of a CNN, has demonstrated to improve several image recognition tasks in remote sensing. However, it is currently unclear if this multi resolution information can also be captured from images with different spatial resolutions like satellite and airborne imagery (from both manned and unmanned platforms). In this paper, a CNN framework using residual connections and dilated convolutions is used considering both manned and unmanned aerial image samples to perform the satellite image classification of building damages. Three network configurations, trained with multi-resolution image samples are compared against two benchmark networks where only satellite image samples are used. Combining feature maps generated from airborne and satellite image samples, and refining these using only the satellite image samples, improved nearly 4 % the overall satellite image

Satellite systems for personal applications concepts and technology

CERN Document Server

Richharia, Madhavendra

2010-01-01

Presents the concepts, technology, and role of satellite systems in support of personal applications, such as mobile and broadband communications, navigation, television, radio and multimedia broadcasting, safety of life services, etc. This book presents a novel perspective on satellite systems, reflecting the modern personal technology context, and hence a focus on the individual as end-user. The book begins by outlining key generic concepts before discussing techniques adopted in particular application areas; next, it exemplifies these techniques through discussion of state-of-art c

47 CFR 25.261 - Procedures for avoidance of in-line interference events for Non Geostationary Satellite Orbit...

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Procedures for avoidance of in-line interference events for Non Geostationary Satellite Orbit (NGSO) Satellite Network Operations in the Fixed Satellite Service (FSS) Bands. 25.261 Section 25.261 Telecommunication FEDERAL COMMUNICATIONS COMMISSION...

A service for the application of data quality information to NASA earth science satellite records

Science.gov (United States)

Armstrong, E. M.; Xing, Z.; Fry, C.; Khalsa, S. J. S.; Huang, T.; Chen, G.; Chin, T. M.; Alarcon, C.

2016-12-01

A recurring demand in working with satellite-based earth science data records is the need to apply data quality information. Such quality information is often contained within the data files as an array of "flags", but can also be represented by more complex quality descriptions such as combinations of bit flags, or even other ancillary variables that can be applied as thresholds to the geophysical variable of interest. For example, with Level 2 granules from the Group for High Resolution Sea Surface Temperature (GHRSST) project up to 6 independent variables could be used to screen the sea surface temperature measurements on a pixel-by-pixel basis. Quality screening of Level 3 data from the Soil Moisture Active Passive (SMAP) instrument can be become even more complex, involving 161 unique bit states or conditions a user can screen for. The application of quality information is often a laborious process for the user until they understand the implications of all the flags and bit conditions, and requires iterative approaches using custom software. The Virtual Quality Screening Service, a NASA ACCESS project, is addressing these issues and concerns. The project has developed an infrastructure to expose, apply, and extract quality screening information building off known and proven NASA components for data extraction and subset-by-value, data discovery, and exposure to the user of granule-based quality information. Further sharing of results through well-defined URLs and web service specifications has also been implemented. The presentation will focus on overall description of the technologies and informatics principals employed by the project. Examples of implementations of the end-to-end web service for quality screening with GHRSST and SMAP granules will be demonstrated.

Antennas for mobile satellite communications

Science.gov (United States)

Huang, John

1991-12-01

A NASA sponsored program, called the Mobile Satellite (MSAT) system, has prompted the development of several innovative antennas at L-band frequencies. In the space segment of the MSAT system, an efficient, light weight, circularly polarized microstrip array that uses linearly polarized elements was developed as a multiple beam reflector feed system. In the ground segment, a low-cost, low-profile, and very efficient microstrip Yagi array was developed as a medium-gain mechanically steered vehicle antenna. Circularly shaped microstrip patches excited at higher-order modes were also developed as low-gain vehicle antennas. A more recent effort called for the development of a 20/30 GHz mobile terminal antenna for future-generation mobile satellite communications. To combat the high insertion loss encountered at 20/30 GHz, series-fed Monolithic Microwave Integrated Circuit (MMIC) microstrip array antennas are currently being developed. These MMIC arrays may lead to the development of several small but high-gain Ka-band antennas for the Personal Access Satellite Service planned for the 2000s.

Integrating Communication and Navigation: Next Generation Broadcast Service (NGBS)

Science.gov (United States)

Donaldson, Jennifer

2017-01-01

NASA Goddard has been investing in technology demonstrations of a beacon service, now called Next Generation Broadcast Services (NGBS). NGBS is a global, space-based, communications and navigation service for users of Global Navigation Satellite Systems (GNSS) and the Tracking and Data Relay Satellite System (TDRSS). NGBS will provide an S-band beacon messaging source and radio navigation available to users at orbital altitudes 1400 km and below, increasing the autonomy and resiliency of onboard communication and navigation. NGBS will deliver both one-way radiometric (Doppler and pseudorange) and fast forward data transport services to users. Portions of the overall forward data volume will be allocated for fixed message types while the remaining data volume will be left for user forward command data. The NGBS signal will reside within the 2106.43 MHz spectrum currently allocated for the Space Networks multiple access forward (MAF) service and a live service demonstration is currently being planned via the 2nd and 3rd generation TDRS satellites.

Commercial TV distribution and broadcast by satellite in the USA

Science.gov (United States)

Debastos, R.

The evolution of DBS satellite systems and their market in the U.S. is described. Anik A, launched in 1972, has been followed by 40 other launches. By 1986 there were 30 functional DBS systems in orbit operating in either C- or K- or hybrid modes of the two bands and providing over 450 channels to subscribers. The television capabilities are being augmented, with FCC approval for 31 new satellites, with Ku-band video, telephony and data transmission systems for small businesses. Features of the RCA Series 4000 and 5000 third generation satellites which will provide the services and lower operating costs passed on to the consumer are summarized, noting the use of TWTAs and high efficiency thermal dissipation systems on the new satellite designs.

Power attenuation characteristics as switch-over criterion in personal satellite mobile communications

Science.gov (United States)

Castro, Jonathan P.

1993-01-01

A third generation mobile system intends to support communications in all environments (i.e., outdoors, indoors at home or office and when moving). This system will integrate services that are now available in architectures such as cellular, cordless, mobile data networks, paging, including satellite services to rural areas. One way through which service integration will be made possible is by supporting a hierarchical cellular structure based on umbrella cells, macro cells, micro and pico cells. In this type of structure, satellites are part of the giant umbrella cells allowing continuous global coverage, the other cells belong to cities, neighborhoods, and buildings respectively. This does not necessarily imply that network operation of terrestrial and satellite segments interconnect to enable roaming and spectrum sharing. However, the cell concept does imply hand-off between different cell types, which may involve change of frequency. Within this propsective, the present work uses power attenuation characteristics to determine a dynamic criterion that allows smooth transition from space to terrestrial networks. The analysis includes a hybrid channel that combines Rician, Raleigh and Log Normal fading characteristics.

Protocoles d'accès multiple orientés qualité de service en constellation de satellite à orbite basse

OpenAIRE

Ibrahim , Abbas

2002-01-01

Pendant les dernières années, le réseau cellulaire est devenu accessible presque partout. Pour compléter ce réseau cellulaire terrestre, plusieurs systèmes basés sur des satellites à basse orbite (LEO Low Earth Orbit) et moyenne orbite (MEO Medium Earth Orbit) ont été développés pour offrir une couverture globale. Les services multimédias sont largement demandés sur une échelle globale.Notre but est de développer une couche d'accès MAC au canal satellitaire tout en respectant les contraintes ...

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

Science.gov (United States)

Hiendlmeier, G.; Schmeller, H.

1991-01-01

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.

Space environment monitoring by low-altitude operational satellites

International Nuclear Information System (INIS)

Kroehl, H.W.

1982-01-01

The primary task of the Defense Meteorological Satellite Program (DMSP) is the acquisition of meteorological data in the visual and infrared spectral regions. The Air Weather Service operates two satellites in low-altitude, sun-synchronous, polar orbits at 850 km altitude, 98.7 deg inclination, 101.5 minute period and dawn-dusk or noon-midnight equatorial crossing times. Special DMSP sensors of interest to the space science community are the precipitating electron spectrometer, the terrestrial noise receiver, and the topside ionosphere plasma monitor. Data from low-altitude, meteorological satellites can be used to build empirical models of precipitating electron characteristics of the auroral zone and polar cap. The Tiros-NOAA satellite program complements the DMSP program. The orbital elements are the same as DMSP's, except for the times of equatorial crossing, and the tilt of the orbital plane. The Tiros-NOAA program meets the civilian community's needs for meteorological data as the DMSP program does for the military

Positional stabilization of communications satellites - The RITA ion propulsion system is ready for commercial use

Science.gov (United States)

The radiofrequency ion thruster assembly (RITA) intended for service aboard the new Artemis communications satellite will operate for three hours twice a day, in order to furnish orbital position adjustments that keep antennas accurately pointed toward the earth. These engines are, despite such frequent and sustained use, projected to eject no more than 30 kG of Xe over the course of a decade. RITA operation is also extremely reliable and, due to its very low propellant consumption, is the basis of a long satellite service life. RITA will be among the 15 experiments that are to be performed by ESA's Eureca research satellite.

Mapping Water Use and Drought with Satellite Remote Sensing

OpenAIRE

Anderson, Martha

2014-01-01

Mapping water use and drought with satellite remote sensing. Martha C. Anderson, Bill Kustas, Feng Gao, Kate Semmens. USDA-Agricultural Research Service Hydrology and Remote Sensing Laboratory, Beltsville, MD. Chris Hain NOAA-NESDIS

GSFC network operations with Tracking and Data Relay Satellites

Science.gov (United States)

Spearing, R.; Perreten, D. E.

The Tracking and Data Relay Satellite System (TDRSS) Network (TN) has been developed to provide services to all NASA User spacecraft in near-earth orbits. Three inter-relating entities will provide these services. The TN has been transformed from a network continuously changing to meet User specific requirements to a network which is flexible to meet future needs without significant changes in operational concepts. Attention is given to the evolution of the TN network, the TN capabilities-space segment, forward link services, tracking services, return link services, the three basic capabilities, single access services, multiple access services, simulation services, the White Sands Ground Terminal, the NASA communications network, and the network control center.

a European Global Navigation Satellite System — the German Market and Value Adding Chain Effects

Science.gov (United States)

Vollerthun, A.; Wieser, M.

2002-03-01

Since Europe is considering to establish a "market-driven" European Global Navigation Satellite System, the German Center of Aerospace initiated a market research to justify a German investment in such a European project. The market research performed included the following market segments: aviation, railway, road traffic, shipping, surveying, farming, military, space applications, leisure, and sport. In these market segments, the forementioned inputs were determined for satellite navigation hardware (receivers) as well as satellite navigation services. The forecast period was from year 2007 to 2017. For the considered period, the market amounts to a total of DM 83.0 billion (approx. US $50 billion), whereas the satellite navigation equipment market makes up DM 39.8 billion, and charges for value-added-services amount to DM 43.2 billion. On closer examination road traffic can be identified as the dominant market share, both in the receiver-market and service-market. With a share of 96% for receivers and 73% for services the significance of the road traffic segment becomes obvious. The second part of this paper investigates the effects the market potential has on the Value-Adding-Chain. Therefore, all participants in the Value-Adding-Chain are identified, using industrial cost structure models the employment effect is analyzed, and possible tax revenues for the state are examined.

A Method for Estimating BeiDou Inter-frequency Satellite Clock Bias

Directory of Open Access Journals (Sweden)

LI Haojun

2016-02-01

Full Text Available A new method for estimating the BeiDou inter-frequency satellite clock bias is proposed, considering the shortage of the current methods. The constant and variable parts of the inter-frequency satellite clock bias are considered in the new method. The data from 10 observation stations are processed to validate the new method. The characterizations of the BeiDou inter-frequency satellite clock bias are also analyzed using the computed results. The results of the BeiDou inter-frequency satellite clock bias indicate that it is stable in the short term. The estimated BeiDou inter-frequency satellite clock bias results are molded. The model results show that the 10 parameters of model for each satellite can express the BeiDou inter-frequency satellite clock bias well and the accuracy reaches cm level. When the model parameters of the first day are used to compute the BeiDou inter-frequency satellite clock bias of the second day, the accuracy also reaches cm level. Based on the stability and modeling, a strategy for the BeiDou satellite clock service is presented to provide the reference of our BeiDou.

Flight Dynamics Operations Management of the Large and Heterogeneous Eutelsat Fleet of Commercial Satellites

Science.gov (United States)

Bellido, E.

The EUTELSAT FDU (Flight Dynamics Unit) manages the resources to perform the typical activities of the large satellite operators and faces the usual difficulties raising from a vast and heterogeneous fleet. At present 20 satellites from 9 different platforms/sub-platforms are controlled from our Satellite Control Centre. The FDU was created in 2002 with the aim to respond to the operational needs of a growing fleet in terms of number of satellites and activities. It is at present composed of 6 engineering staff with the objective to provide operations service covering the whole lifecycle of the satellites from the procurement phase till the decommissioning. The most demanding activity is the daily operations, which must ensure maximum safety and continuity of service with the highest efficiency. Solutions have been applied from different areas: management, structure, operations organisation, processes, facilities, quality standards, etc. In addition to this, EUTELSAT is a growing communications operator and the FDU needs to contribute to the global objectives of the company. This paper covers our approach.

42 CFR 410.78 - Telehealth services.

Science.gov (United States)

2010-10-01

...-based renal dialysis center (including satellites). (vii) A skilled nursing facility (as defined in... as telehealth services. (f) Process for adding or deleting services. Changes to the list of Medicare...

Planning and Scheduling for Fleets of Earth Observing Satellites

Science.gov (United States)

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

2001-01-01

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

Preparing Precipitation Data Access, Value-added Services and Scientific Exploration Tools for the Integrated Multi-satellitE Retrievals for GPM (IMERG)

Science.gov (United States)

Ostrenga, D.; Liu, Z.; Kempler, S. J.; Vollmer, B.; Teng, W. L.

2013-12-01

The Precipitation Data and Information Services Center (PDISC) (http://disc.gsfc.nasa.gov/precipitation or google: NASA PDISC), located at the NASA Goddard Space Flight Center (GSFC) Earth Sciences (GES) Data and Information Services Center (DISC), is home of the Tropical Rainfall Measuring Mission (TRMM) data archive. For over 15 years, the GES DISC has served not only TRMM, but also other space-based, airborne-based, field campaign and ground-based precipitation data products to the precipitation community and other disciplinary communities as well. The TRMM Multi-Satellite Precipitation Analysis (TMPA) products are the most popular products in the TRMM product family in terms of data download and access through Mirador, the GES-DISC Interactive Online Visualization ANd aNalysis Infrastructure (Giovanni) and other services. The next generation of TMPA, the Integrated Multi-satellitE Retrievals for GPM (IMERG) to be released in 2014 after the launch of GPM, will be significantly improved in terms of spatial and temporal resolutions. To better serve the user community, we are preparing data services and samples are listed below. To enable scientific exploration of Earth science data products without going through complicated and often time consuming processes, such as data downloading, data processing, etc., the GES DISC has developed Giovanni in consultation with members of the user community, requesting quick search, subset, analysis and display capabilities for their specific data of interest. For example, the TRMM Online Visualization and Analysis System (TOVAS, http://disc2.nascom.nasa.gov/Giovanni/tovas/) has proven extremely popular, especially as additional datasets have been added upon request. Giovanni will continue to evolve to accommodate GPM data and the multi-sensor data inter-comparisons that will be sure to follow. Additional PDISC tool and service capabilities being adapted for GPM data include: An on-line PDISC Portal (includes user guide, etc

Evaluation of spacecraft technology programs (effects on communication satellite business ventures), volume 1

Science.gov (United States)

Greenburg, J. S.; Gaelick, C.; Kaplan, M.; Fishman, J.; Hopkins, C.

1985-01-01

Commercial organizations as well as government agencies invest in spacecraft (S/C) technology programs that are aimed at increasing the performance of communications satellites. The value of these programs must be measured in terms of their impacts on the financial performane of the business ventures that may ultimately utilize the communications satellites. An economic evaluation and planning capability was developed and used to assess the impact of NASA on-orbit propulsion and space power programs on typical fixed satellite service (FSS) and direct broadcast service (DBS) communications satellite business ventures. Typical FSS and DBS spin and three-axis stabilized spacecraft were configured in the absence of NASA technology programs. These spacecraft were reconfigured taking into account the anticipated results of NASA specified on-orbit propulsion and space power programs. In general, the NASA technology programs resulted in spacecraft with increased capability. The developed methodology for assessing the value of spacecraft technology programs in terms of their impact on the financial performance of communication satellite business ventures is described. Results of the assessment of NASA specified on-orbit propulsion and space power technology programs are presented for typical FSS and DBS business ventures.

Satellite data transferring subsystem based on system 'Materik'

International Nuclear Information System (INIS)

Belogub, V.P.; Kal'schikov, I.B.; Kirillov, Yu.K.; Kulikov, V.N.; Shumov, A.N.

1998-01-01

One of the most important indicators of successful function of the International Monitoring System is existence of highly reliable communication channels providing transfer data from observation points in a real time scales. Up to present, the most communication channels were provided with existing VF-channels (Voice Frequency) that are relatively low-speedy in transfer process (4.8-9.6 kbit/sec.). In addition, reliability of the channels is insufficient because of many retransmission points. In connection with it, the special control service of MD RF decided to improve the information transfer system (ITS) installed between the observation point and National Data Center (Dubna-city). The improvement of the ITS comprises replacement of wire lines of VF-channels with satellite ones within the framework of the computer-aided satellite communication system (CASCS) M aterik . Besides it was considered to be expedient that the satellite system of data transfer from NPP to the Crisis Center of 'ROSENERGOATOM' Concern would be combined with CASCS M aterik , using the facilities of the Central Earth Station of Satellite Communication (CESSC) in Dubna. Such approach to the creation of Satellite communication has advantages in solution of radiation safety and global monitoring issues

47 CFR 25.278 - Additional coordination obligation for non-geostationary and geostationary satellite systems in...

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Additional coordination obligation for non-geostationary and geostationary satellite systems in frequencies allocated to the fixed-satellite service. 25.278 Section 25.278 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER...

A systems approach to the commercialization of space communications technology - The NASA/JPL Mobile Satellite Program

Science.gov (United States)

Weber, William J., III; Gray, Valerie W.; Jackson, Byron; Steele, Laura C.

1991-10-01

This paper discusss the systems approach taken by NASA and the Jet Propulsion Laboratory in the commercialization of land-mobile satellite services (LMSS) in the United States. As the lead center for NASA's Mobile Satellite Program, JPL was involved in identifying and addressing many of the key barriers to commercialization of mobile satellite communications, including technical, economic, regulatory and institutional risks, or uncertainties. The systems engineering approach described here was used to mitigate these risks. The result was the development and implementation of the JPL Mobile Satellite Experiment Project. This Project included not only technology development, but also studies to support NASA in the definition of the regulatory, market, and investment environments within which LMSS would evolve and eventually operate, as well as initiatives to mitigate their associated commercialization risks. The end result of these government-led endeavors was the acceleration of the introduction of commercial mobile satellite services, both nationally and internationally.

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

Science.gov (United States)

Wilson, Jeffrey D.

2013-01-01

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

Tracking and Data Relay Satellite System /TDRSS/ telecommunication services

Science.gov (United States)

Deerkoski, L. F.

1975-01-01

The TDRSS and tracking services define the telecommunication performance of the TDRSS between the RF interface with user spacecraft and the data interface with NASCOM at the ground terminal. Attention is given to system constraints, forward link services, multiple-access signal design parameters, S-band single access signal design parameters, multiple-access return link services, and single-access return link services.

Static and kinematic positioning using WADGPS from geostationary satellites

Science.gov (United States)

Cefalo, R.; Gatti, M.

2003-04-01

STATIC AND KINEMATIC POSITIONING USING WADGPS CORRECTIONS FROM GEOSTATIONARY SATELLITES Cefalo R. (1), Gatti M (2) (1) Department of Civil Engineering, University of Trieste, P.le Europa 1, 34127 Trieste, Italy, cefalo@dic.univ.trieste.it, (2) Department of Engineering, University of Ferrara, via Saragat 1, 44100 Ferrara, Italy, mgatti@ing.unife.it ABSTRACT. Starting from February 2000, static and kinematic experiments have been performed at the Department of Civil Engineering of University of Trieste, Italy and the Department of Engineering of University of Ferrara, Italy, using the WADGPS (Wide Area Differential GPS) corrections up linked by Geostationary Satellites belonging to the American WAAS and European EGNOS. Recently, a prototypal service by ESA (European Space Agency) named SISNet (Signal In Space through Internet), has been introduced using Internet to diffuse the messages up linked through AOR-E and IOR Geostationary Satellites. This service will overcome the problems relative to the availability of the corrections in urban areas. This system is currently under tests by the authors in order to verify the latency of the message and the applicability and accuracies obtainable in particular in dynamic applications.

DOD Use of Commercial Wideband Satellite Communications Systems: How Much is Needed, and How Do We Get It?

National Research Council Canada - National Science Library

Hutchens, Robert

2001-01-01

..., A key enabler to this end is sufficient wideband satellite communications connectivity DoD's organic wideband satellite communications capabilities are inadequate, so commercial services must be used...

gProcess and ESIP Platforms for Satellite Imagery Processing over the Grid

Science.gov (United States)

Bacu, Victor; Gorgan, Dorian; Rodila, Denisa; Pop, Florin; Neagu, Gabriel; Petcu, Dana

2010-05-01

The Environment oriented Satellite Data Processing Platform (ESIP) is developed through the SEE-GRID-SCI (SEE-GRID eInfrastructure for regional eScience) co-funded by the European Commission through FP7 [1]. The gProcess Platform [2] is a set of tools and services supporting the development and the execution over the Grid of the workflow based processing, and particularly the satelite imagery processing. The ESIP [3], [4] is build on top of the gProcess platform by adding a set of satellite image processing software modules and meteorological algorithms. The satellite images can reveal and supply important information on earth surface parameters, climate data, pollution level, weather conditions that can be used in different research areas. Generally, the processing algorithms of the satellite images can be decomposed in a set of modules that forms a graph representation of the processing workflow. Two types of workflows can be defined in the gProcess platform: abstract workflow (PDG - Process Description Graph), in which the user defines conceptually the algorithm, and instantiated workflow (iPDG - instantiated PDG), which is the mapping of the PDG pattern on particular satellite image and meteorological data [5]. The gProcess platform allows the definition of complex workflows by combining data resources, operators, services and sub-graphs. The gProcess platform is developed for the gLite middleware that is available in EGEE and SEE-GRID infrastructures [6]. gProcess exposes the specific functionality through web services [7]. The Editor Web Service retrieves information on available resources that are used to develop complex workflows (available operators, sub-graphs, services, supported resources, etc.). The Manager Web Service deals with resources management (uploading new resources such as workflows, operators, services, data, etc.) and in addition retrieves information on workflows. The Executor Web Service manages the execution of the instantiated workflows

Comparative study of FDMA, TDMA and hybrid 30/20 GHz satellite communications systems for small users

Science.gov (United States)

Berk, G.; Jean, P. N.; Rotholz, E.

1982-01-01

This study compares several satellite uplink and downlink accessing schemes for a Customer Premises Service. Four conceptual system designs are presented: Satellite-Routed FDMA, Frequency-Routed TDMA, Satellite-Switched TDMA, and Processor-Routed TDMA, operating in the 30/20 GHz band. The designs are compared on the basis of estimated satellite weight, power consumption, and cost. The system capacities are analyzed for a fixed multibeam coverage of CONUS. Analysis shows that the system capacity is limited by the available satellite resources and by the terminal size and cost.

Operational monitoring and forecasting of bathing water quality through exploiting satellite Earth observation and models: The AlgaRisk demonstration service

Science.gov (United States)

Shutler, J. D.; Warren, M. A.; Miller, P. I.; Barciela, R.; Mahdon, R.; Land, P. E.; Edwards, K.; Wither, A.; Jonas, P.; Murdoch, N.; Roast, S. D.; Clements, O.; Kurekin, A.

2015-04-01

Coastal zones and shelf-seas are important for tourism, commercial fishing and aquaculture. As a result the importance of good water quality within these regions to support life is recognised worldwide and a number of international directives for monitoring them now exist. This paper describes the AlgaRisk water quality monitoring demonstration service that was developed and operated for the UK Environment Agency in response to the microbiological monitoring needs within the revised European Union Bathing Waters Directive. The AlgaRisk approach used satellite Earth observation to provide a near-real time monitoring of microbiological water quality and a series of nested operational models (atmospheric and hydrodynamic-ecosystem) provided a forecast capability. For the period of the demonstration service (2008-2013) all monitoring and forecast datasets were processed in near-real time on a daily basis and disseminated through a dedicated web portal, with extracted data automatically emailed to agency staff. Near-real time data processing was achieved using a series of supercomputers and an Open Grid approach. The novel web portal and java-based viewer enabled users to visualise and interrogate current and historical data. The system description, the algorithms employed and example results focussing on a case study of an incidence of the harmful algal bloom Karenia mikimotoi are presented. Recommendations and the potential exploitation of web services for future water quality monitoring services are discussed.

14 CFR 1215.103 - Services.

Science.gov (United States)

2010-01-01

... Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION TRACKING AND DATA RELAY SATELLITE SYSTEM... transmission service. (4) Emergency line outage recording in the event of a communications failure between...-launch support planning and documentation. (9) Scheduling user services via TDRSS. (10) Access to...

Operational use of open satellite data for marine water quality monitoring

Science.gov (United States)

Symeonidis, Panagiotis; Vakkas, Theodoros

2017-09-01

The purpose of this study was to develop an operational platform for marine water quality monitoring using near real time satellite data. The developed platform utilizes free and open satellite data available from different data sources like COPERNICUS, the European Earth Observation Initiative, or NASA, from different satellites and instruments. The quality of the marine environment is operationally evaluated using parameters like chlorophyll-a concentration, water color and Sea Surface Temperature (SST). For each parameter, there are more than one dataset available, from different data sources or satellites, to allow users to select the most appropriate dataset for their area or time of interest. The above datasets are automatically downloaded from the data provider's services and ingested to the central, spatial engine. The spatial data platform uses the Postgresql database with the PostGIS extension for spatial data storage and Geoserver for the provision of the spatial data services. The system provides daily, 10 days and monthly maps and time series of the above parameters. The information is provided using a web client which is based on the GET SDI PORTAL, an easy to use and feature rich geospatial visualization and analysis platform. The users can examine the temporal variation of the parameters using a simple time animation tool. In addition, with just one click on the map, the system provides an interactive time series chart for any of the parameters of the available datasets. The platform can be offered as Software as a Service (SaaS) to any area in the Mediterranean region.

Application of Vision Metrology to In-Orbit Measurement of Large Reflector Onboard Communication Satellite for Next Generation Mobile Satellite Communication

Science.gov (United States)

Akioka, M.; Orikasa, T.; Satoh, M.; Miura, A.; Tsuji, H.; Toyoshima, M.; Fujino, Y.

2016-06-01

Satellite for next generation mobile satellite communication service with small personal terminal requires onboard antenna with very large aperture reflector larger than twenty meters diameter because small personal terminal with lower power consumption in ground base requires the large onboard reflector with high antenna gain. But, large deployable antenna will deform in orbit because the antenna is not a solid dish but the flexible structure with fine cable and mesh supported by truss. Deformation of reflector shape deteriorate the antenna performance and quality and stability of communication service. However, in case of digital beam forming antenna with phased array can modify the antenna beam performance due to adjustment of excitation amplitude and excitation phase. If we can measure the reflector shape precisely in orbit, beam pattern and antenna performance can be compensated with the updated excitation amplitude and excitation phase parameters optimized for the reflector shape measured every moment. Softbank Corporation and National Institute of Information and Communications Technology has started the project "R&D on dynamic beam control technique for next generation mobile communication satellite" as a contracted research project sponsored by Ministry of Internal Affairs and Communication of Japan. In this topic, one of the problem in vision metrology application is a strong constraints on geometry for camera arrangement on satellite bus with very limited space. On satellite in orbit, we cannot take many images from many different directions as ordinary vision metrology measurement and the available area for camera positioning is quite limited. Feasibility of vision metrology application and general methodology to apply to future mobile satellite communication satellite is to be found. Our approach is as follows: 1) Development of prototyping simulator to evaluate the expected precision for network design in zero order and first order 2) Trial

Saturn satellites

International Nuclear Information System (INIS)

Ruskol, E.L.

1981-01-01

The characteristics of the Saturn satellites are discussed. The satellites close to Saturn - Janus, Mimas, Enceladus, Tethys, Dione and Rhea - rotate along the circular orbits. High reflectivity is attributed to them, and the density of the satellites is 1 g/cm 3 . Titan is one of the biggest Saturn satellites. Titan has atmosphere many times more powerful than that of Mars. The Titan atmosphere is a peculiar medium with a unique methane and hydrogen distribution in the whole Solar system. The external satellites - Hyperion, Japetus and Phoebe - are poorly investigated. Neither satellite substance density, nor their composition are known. The experimental data on the Saturn rings obtained on the ''Pioneer-11'' and ''Voyager-1'' satellites are presented [ru

Trends in the commercial launch services industry

Science.gov (United States)

Haase, Ethan E.

2001-02-01

The market for space launch services has undergone significant development in the last two decades and is poised to change even further. With the introduction of new players in the market, and the development of new vehicles by existing providers, competition has increased. At the same time, customer payloads have been changing as satellites grow in size and capability. Amidst these changes, launch delays have become a concern in the industry, and launch service providers have developed different solutions to avoid delays and satisfy customer needs. This analysis discusses these trends in the launch services market and their drivers. Focus is given to the market for medium, intermediate, and heavy launch services which generally includes launches of GEO communication satellites, large government payloads, and NGSO constellations. .

Propagation considerations in land mobile satellite transmission

Science.gov (United States)

Vogel, W. J.; Smith, E. K.

1985-01-01

It appears likely that the Land Mobile Satellite Services (LMSS) will be authorized by the FCC for operation in the 800 to 900 MHz (UHF) and possibly near 1500 MHz (L-band). Propagation problems are clearly an important factor in the effectiveness of this service, but useful measurements are few, and produced contradictory interpretations. A first order overview of existing measurements is presented with particular attention to the first two NASA balloon to mobile vehicle propagation experiments. Some physical insight into the interpretation of propagation effects in LMSS transmissions is provided.

Technology programs and related policies - Impacts on communications satellite business ventures

Science.gov (United States)

Greenberg, J. S.

1985-01-01

The DOMSAT II stochastic communication satellite business venture financial planning simulation model is described. The specification of business scenarios and the results of several analyses are presented. In particular, the impacts of NASA on-orbit propulsion and power technology programs are described. The effects of insurance rates and self-insurance and of the use of the Space Shuttle and Ariane transportation systems on a typical fixed satellite service business venture are discussed.

Global mobile satellite communications theory for maritime, land and aeronautical applications

CERN Document Server

Ilčev, Stojče Dimov

2017-01-01

This book discusses current theory regarding global mobile satellite communications (GMSC) for maritime, land (road and rail), and aeronautical applications. It covers how these can enable connections between moving objects such as ships, road and rail vehicles and aircrafts on one hand, and on the other ground telecommunications subscribers through the medium of communications satellites, ground earth stations, Terrestrial Telecommunication Networks (TTN), Internet Service Providers (ISP) and other wireless and landline telecommunications providers. This new edition covers new developments and initiatives that have resulted in land and aeronautical applications and the introduction of new satellite constellations in non-geostationary orbits and projects of new hybrid satellite constellations. The book presents current GMSC trends, mobile system concepts and network architecture using a simple mode of style with understandable technical information, characteristics, graphics, illustrations and mathematics equ...

The UNOSAT-GRID Project: Access to Satellite Imagery through the Grid Environment

CERN Document Server

Méndez-Lorenzo, P; Lamanna, M; Meyer, X; Lazeyras, M; Bjorgo, E; Retiere, A; Falzone, A; Venuti, N; Maccarone, S; Ugolotti, B

2007-01-01

UNOSAT is a United Nations activity to provide access to satellite images and geographic system services for humanitarian operations for rescue or aid activities. UNOSAT is implemented by the UN Institute for Training and Research (UNITAR) and managed by the UN Office for Project Services (UNOPS). In addition, partners from different organizations constitute the UNOSAT consortium. Among these partners, CERN participates actively providing the required computational and storage resources. The critical part of the UNOSAT activity is the storage and processing of large quantities of satellite images. The fast and secure access to these images from any part of the world is mandatory during these activities. Based on two successful CERN-GRID/UNOSAT pilot projects (data storage/compression/download and image access through mobile phone), the GRIDUNOSAT project has consolidated the considerable work undertaken so far in the present activity. The main use case already demonstrated is the delivery of satellite images ...

Exploring Modular Architecture for Nano Satellite and Opportunity for Developing Countries

Science.gov (United States)

Rhaman, M. K.; Monowar, M. I.; Shakil, S. R.; Kafi, A. H.; Antara, R. S. I.

2015-01-01

SPACE Technology has the potential to provide information, infrastructure and inspiration that meets national needs in developing countries like Bangladesh. Many countries recognize this; in response they are investing in new national satellite programs to harness satellite services. Technology related to space is one example of a tool that can contribute to development both by addressing societal challenges and by advancing a nation's technological capability. To cope up with the advanced world in space technology Bangladesh seems to be highly potential country for satellite, Robotics, embedded systems and renewable energy research. BRAC University, Bangladesh is planning to launch a nano satellite with the collaboration of KIT, Japan. The proposed nano satellite project mission is to experiment about social, commercial and agricultural survey needs in Bangladesh. Each of the proposed applications of the project will improve the lives of millions of people of Bangladesh and it will be a pathfinder mission for the people of this country. Another intention of this project is to create a cheap satellite based remote sensing for developing countries as the idea of large space systems is very costly for us therefore we have decided to make a Nano-satellite.

Exploring Modular Architecture for Nano Satellite and Opportunity for Developing Countries

International Nuclear Information System (INIS)

Rhaman, M K; Monowar, M I; Shakil, S R; Kafi, A H; Antara, R S I

2015-01-01

SPACE Technology has the potential to provide information, infrastructure and inspiration that meets national needs in developing countries like Bangladesh. Many countries recognize this; in response they are investing in new national satellite programs to harness satellite services. Technology related to space is one example of a tool that can contribute to development both by addressing societal challenges and by advancing a nation's technological capability. To cope up with the advanced world in space technology Bangladesh seems to be highly potential country for satellite, Robotics, embedded systems and renewable energy research. BRAC University, Bangladesh is planning to launch a nano satellite with the collaboration of KIT, Japan. The proposed nano satellite project mission is to experiment about social, commercial and agricultural survey needs in Bangladesh. Each of the proposed applications of the project will improve the lives of millions of people of Bangladesh and it will be a pathfinder mission for the people of this country. Another intention of this project is to create a cheap satellite based remote sensing for developing countries as the idea of large space systems is very costly for us therefore we have decided to make a Nano-satellite

On board processing for future satellite communications systems: Comparison of FDM, TDM and hybrid accessing schemes

Science.gov (United States)

Berk, G.; Jean, P. N.; Rotholz, E.

1982-01-01

Several satellite uplink and downlink accessing schemes for customer premises service are compared. Four conceptual system designs are presented: satellite-routed frequency division multiple access (FDMA), satellite-switched time division multiple access (TDMA), processor-routed TDMA, and frequency-routed TDMA, operating in the 30/20 GHz band. The designs are compared on the basis of estimated satellite weight, system capacity, power consumption, and cost. The systems are analyzed for fixed multibeam coverage of the continental United States. Analysis shows that the system capacity is limited by the available satellite resources and by the terminal size and cost.

INMARSAT - The International Maritime Satellite Organization: Origins and structure

Science.gov (United States)

Doyle, S. E.

1977-01-01

The third session of the International Conference on the Establishment of an International Maritime Satellite System established the International Maritime Satellite Organization (INMARSAT) in 1976. Its main functions are to improve maritime communications via satellite, thereby facilitating more efficient emergency communications, ship management, and maritime public correspondence services. INMARSAT's aims are similar to those of the Intergovernmental Maritime Consultative Organization (IMCO), the main United Nations organization dealing with maritime affairs. The specific functions of INMARSAT have been established by an Intersessional Working Group (IWG) which met three times between general conference meetings. Initial investment shares for the creation of INMARSAT were shared by the United States (17%), the United Kingdom (12%), the U.S.S.R. (11%), Norway (9.50%), Japan (8.45%), Italy (4.37%), and France (3.50%).

Local network interconnection through a satellite point-to-multipoint link. Ph.D. Thesis - Ecole Nationale Superieure des Telecommunications, 6 Jul. 1985

Science.gov (United States)

Duarte, O. Muniz Bandeira

1986-01-01

Four architectures to implement a point to multipoint satellite link protocol for communication services offered by the Telecom 1 satellite network are presented. A safe communication service with error correction and flow control facilities is described. It is shown that a time transparent communication system combines simplicity and cost advantages.

Triple Play over Satellite, Ka-Band Making the Difference

Science.gov (United States)

Benoit, Guillaume; Fenech, Hector; Pezzana, Stefano

Over the last years a number of operators have been deploying satellite-based consumer internet access services to reduce the digital divide and capture the market of households not covered by ADSL, cable or wireless broadband. These operators are proposing a step change improvement in the economics of consumer service, with lower terminal costs, broadband access with monthly fees comparable to ADSL and an integrated technology simplifying the process of terminal installation, provisioning and management.

LMSS - From low data rate to voice services

Science.gov (United States)

Rogard, R.

1992-03-01

An overview of ESA's approach towards the introduction of Land Mobile Communications in Europe is presented. Emphasis is placed on a description of the payload called EMS to be launched on a host satellite, the Italsat-F2 spacecraft, and the definition of services which are most appropriate for a first-generation-operating Land Mobile Satellite System, namely, PRODAT, a message-handling system, and Europhone, an original approach to 'voice' systems. Attention is given to the EMS payload, characteristics, and capacity, the IF processor and channelization, and market considerations. It is shown that the optimization of the satellite characteristics and the mix of services to be provided are the key elements of a successful entry into the market.

A network architecture for International Business Satellite communications

Science.gov (United States)

Takahata, Fumio; Nohara, Mitsuo; Takeuchi, Yoshio

Demand Assignment (DA) control is expected to be introduced in the International Business Satellte communications (IBS) network in order to cope with a growing international business traffic. The paper discusses the DA/IBS network from the viewpoints of network configuration, satellite channel configuration and DA control. The network configuration proposed here consists of one Central Station with network management function and several Network Coordination Stations with user management function. A satellite channel configuration is also presented along with a tradeoff study on transmission bit rate, high power amplifier output power requirement, and service quality. The DA control flow and protocol based on CCITT Signalling System No. 7 are also proposed.

Secure, Autonomous, Intelligent Controller for Integrating Distributed Emergency Response Satellite Operations

Science.gov (United States)

Ivancic, William D.; Paulsen, Phillip E.; Miller, Eric M.; Sage, Steen P.

2013-01-01

This report describes a Secure, Autonomous, and Intelligent Controller for Integrating Distributed Emergency Response Satellite Operations. It includes a description of current improvements to existing Virtual Mission Operations Center technology being used by US Department of Defense and originally developed under NASA funding. The report also highlights a technology demonstration performed in partnership with the United States Geological Service for Earth Resources Observation and Science using DigitalGlobe(Registered TradeMark) satellites to obtain space-based sensor data.

Advance Technology Satellites in the Commercial Environment. Volume 2: Final Report

Science.gov (United States)

1984-01-01

A forecast of transponder requirements was obtained. Certain assumptions about system configurations are implicit in this process. The factors included are interpolation of baseline year values to produce yearly figures, estimation of satellite capture, effects of peak-hours and the time-zone staggering of peak hours, circuit requirements for acceptable grade of service capacity of satellite transponders, including various compression methods where applicable, and requirements for spare transponders in orbit. The graphical distribution of traffic requirements was estimated.

New Opportunitie s for Small Satellite Programs Provided by the Falcon Family of Launch Vehicles

Science.gov (United States)

Dinardi, A.; Bjelde, B.; Insprucker, J.

2008-08-01

The Falcon family of launch vehicles, developed by Space Exploration Technologies Corporation (SpaceX), are designed to provide the world's lowest cost access to orbit. Highly reliable, low cost launch services offer considerable opportunities for risk reduction throughout the life cycle of satellite programs. The significantly lower costs of Falcon 1 and Falcon 9 as compared with other similar-class launch vehicles results in a number of new business case opportunities; which in turn presents the possibility for a paradigm shift in how the satellite industry thinks about launch services.

Current state of art of satellite altimetry

Science.gov (United States)

Łyszkowicz, Adam Bolesław; Bernatowicz, Anna

2017-12-01

One of the fundamental problems of modern geodesy is precise defi nition of the gravitational fi eld and its changes in time. This is essential in positioning and navigation, geophysics, geodynamics, oceanography and other sciences related to the climate and Earth's environment. One of the major sources of gravity data is satellite altimetry that provides gravity data with almost 75% surface of the Earth. Satellite altimetry also provides data to study local, regional and global geophysical processes, the geoid model in the areas of oceans and seas. This technique can be successfully used to study the ocean mean dynamic topography. The results of the investigations and possible products of altimetry will provide a good material for the GGOS (Global Geodetic Observing System) and institutions of IAS (International Altimetry Service). This paper presents the achievements in satellite altimetry in all the above disciplines obtained in the last years. First very shorly basic concept of satellite altimetry is given. In order to obtain the highest accuracy on range measurements over the ocean improved of altimetry waveforms performed on the ground is described. Next, signifi cant improvements of sea and ocean gravity anomalies models developed presently is shown. Study of sea level and its extremes examined, around European and Australian coasts using tide gauges data and satellite altimetry measurements were described. Then investigations of the phenomenon of the ocean tides, calibration of altimeters, studies of rivers and ice-sheets in the last years are given.

Current state of art of satellite altimetry

Directory of Open Access Journals (Sweden)

Łyszkowicz Adam Bolesław

2017-12-01

Full Text Available One of the fundamental problems of modern geodesy is precise defi nition of the gravitational fi eld and its changes in time. This is essential in positioning and navigation, geophysics, geodynamics, oceanography and other sciences related to the climate and Earth’s environment. One of the major sources of gravity data is satellite altimetry that provides gravity data with almost 75% surface of the Earth. Satellite altimetry also provides data to study local, regional and global geophysical processes, the geoid model in the areas of oceans and seas. This technique can be successfully used to study the ocean mean dynamic topography. The results of the investigations and possible products of altimetry will provide a good material for the GGOS (Global Geodetic Observing System and institutions of IAS (International Altimetry Service. This paper presents the achievements in satellite altimetry in all the above disciplines obtained in the last years. First very shorly basic concept of satellite altimetry is given. In order to obtain the highest accuracy on range measurements over the ocean improved of altimetry waveforms performed on the ground is described. Next, signifi cant improvements of sea and ocean gravity anomalies models developed presently is shown. Study of sea level and its extremes examined, around European and Australian coasts using tide gauges data and satellite altimetry measurements were described. Then investigations of the phenomenon of the ocean tides, calibration of altimeters, studies of rivers and ice-sheets in the last years are given.

Cibola flight experiment satellite

Science.gov (United States)

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

2004-11-01

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

Forecast of space shuttle flight requirements for launch of commercial communications satellites

Science.gov (United States)

1977-01-01

The number of communication satellites required over the next 25 years to support domestic and regional communication systems for telephony, telegraphy and other low speed data; video teleconferencing, new data services, direct TV broadcasting; INTELSAT; and maritime and aeronautical services was estimated to determine the number of space shuttle flights necessary for orbital launching.

In-Space Internet-Based Communications for Space Science Platforms Using Commercial Satellite Networks

Science.gov (United States)

Kerczewski, Robert J.; Bhasin, Kul B.; Fabian, Theodore P.; Griner, James H.; Kachmar, Brian A.; Richard, Alan M.

1999-01-01

The continuing technological advances in satellite communications and global networking have resulted in commercial systems that now can potentially provide capabilities for communications with space-based science platforms. This reduces the need for expensive government owned communications infrastructures to support space science missions while simultaneously making available better service to the end users. An interactive, high data rate Internet type connection through commercial space communications networks would enable authorized researchers anywhere to control space-based experiments in near real time and obtain experimental results immediately. A space based communications network architecture consisting of satellite constellations connecting orbiting space science platforms to ground users can be developed to provide this service. The unresolved technical issues presented by this scenario are the subject of research at NASA's Glenn Research Center in Cleveland, Ohio. Assessment of network architectures, identification of required new or improved technologies, and investigation of data communications protocols are being performed through testbed and satellite experiments and laboratory simulations.

Graphical Programming: A systems approach for telerobotic servicing of space assets

International Nuclear Information System (INIS)

Pinkerton, J.T.; Patten, R.

1993-01-01

Satellite servicing is in many ways analogous to subsea robotic servicing in the late 1970's. A cost effective, reliable, telerobotic capability had to be demonstrated before the oil companies invested money in deep water robot serviceable production facilities. In the same sense, aeronautic engineers will not design satellites for telerobotic servicing until such a quantifiable capability has been demonstrated. New space servicing systems will be markedly different than existing space robot systems. Past space manipulator systems, including the Space Shuttle's robot arm, have used master/slave technologies with poor fidelity, slow operating speeds and most importantly, in-orbit human operators. In contrast, new systems will be capable of precision operations, conducted at higher rates of speed, and be commanded via ground-control communication links. Challenges presented by this environment include achieving a mandated level of robustness and dependability, radiation hardening, minimum weight and power consumption, and a system which accommodates the inherent communication delay between the ground station and the satellite. There is also a need for a user interface which is easy to use, ensures collision free motions, and is capable of adjusting to an unknown workcell (for repair operations the condition of the satellite may not be known in advance). This paper describes the novel technologies required to deliver such a capability

PEGASUS - A Flexible Launch Solution for Small Satellites with Unique Requirements

Science.gov (United States)

Richards, B. R.; Ferguson, M.; Fenn, P. D.

The financial advantages inherent in building small satellites are negligible if an equally low cost launch service is not available to deliver them to the orbit they require. The weight range of small satellites puts them within the capability of virtually all launch vehicles. Initially, this would appear to help drive down costs through competition since, by one estimate, there are roughly 75 active space launch vehicles around the world that either have an established flight record or are planning to make an inaugural launch within the year. When reliability, budget constraints, and other issues such as inclination access are factored in, this list of available launch vehicles is often times reduced to a very limited few, if any at all. This is especially true for small satellites with unusual or low inclination launch requirements where the cost of launching on the heavy-lift launchers that have the capacity to execute the necessary plane changes or meet the mission requirements can be prohibitive. For any small satellite, reducing launch costs by flying as a secondary or even tertiary payload is only advantageous in the event that a primary payload can be found that either requires or is passing through the same final orbit and has a launch date that is compatible. If the satellite is able to find a ride on a larger vehicle that is only passing through the correct orbit, the budget and technical capability must exist to incorporate a propulsive system on the satellite to modify the orbit to that required for the mission. For these customers a launch vehicle such as Pegasus provides a viable alternative due to its proven flight record, relatively low cost, self- contained launch infrastructure, and mobility. Pegasus supplements the existing world-wide launch capability by providing additional services to a targeted niche of payloads that benefit greatly from Pegasus' mobility and flexibility. Pegasus can provide standard services to satellites that do not

Characterizing SPDY over High Latency Satellite Channels

Directory of Open Access Journals (Sweden)

Luca Caviglione

2014-12-01

Full Text Available The increasing complexity ofWeb contents and the growing diffusion of mobile terminals, which use wireless and satellite links to get access to the Internet, impose the adoption of more specialized protocols. In particular, we focus on SPDY, a novel protocol introduced by Google to optimize the retrieval of complex webpages, to manage large Round Trip Times and high packet losses channels. In this perspective, the paper characterizes SPDY over high latency satellite links, especially with the goal of understanding whether it could be an efficient solution to cope with performance degradations typically affecting Web 2.0 services. To this aim, we implemented an experimental set-up, composed of an ad-hoc proxy, a wireless link emulator, and an instrumented Web browser. The results clearly indicate that SPDY can enhance the performances in terms of loading times, and reduce the traffic fragmentation. Moreover, owing to its connection multiplexing architecture, SPDY can also mitigate the transport layer complexity, which is critical when in presence of Performance Enhancing Proxies usually deployed to isolate satellite trunks.

47 CFR 25.284 - Emergency Call Center Service.

Science.gov (United States)

2010-10-01

... mobile satellite service to end-user customers (part 25, subparts A-D) must provide Emergency Call Center... Center personnel must determine the emergency caller's phone number and location and then transfer or otherwise redirect the call to an appropriate public safety answering point. Providers of mobile satellite...

Customer premises services market demand assessment 1980 - 2000. Volume 1: Executive summary

Science.gov (United States)

Gamble, R. B.; Saporta, L.; Heidenrich, G. A.

1983-01-01

Estimates of market demand for domestic civilian telecommunications services for the years 1980 to 2000 are provided. Overall demand, demand or satellite services, demand for satellite delivered Customer Premises Service (CPS), and demand for 30/20 GHz Customer Premises Services are covered. Emphasis is placed on the CPS market and demand is segmented by market, by service, by user class and by geographic region. Prices for competing services are discussed and the distribution of traffic with respect to distance is estimated. A nationwide traffic distribution model for CPS in terms of demand for CPS traffic and earth stations for each of the major SMSAs in the United States are provided.

Nigeria's Satellite Programme Development: Prospects and Challenges

Science.gov (United States)

Akinyede, Joseph

Nigeria's desire to maximize the benefits of space technology for its sustainable development, has become a reality with the establishment of the National Space Research and Development Agency (NASRDA) in May 1999 and the approval of the national Space Policy and Programmes in July 2001. In November, 2000, the Federal Government took a bold step with the signing of an agreement with the Surrey Satellite Technology Limited (SSTL) of United Kingdom (UK) for the design, construction and launch of a medium resolution micro-satellite - NigeriaSat-1 with a Ground Sampling Distance of thirty-two (32) meters. The agreement also covers the Know-How-Technology-Training (KHTT) to Nigerian Engineers and Scientists for a period of 18th months at SSTL‘s facility in the U.K.. NigeriaSat-1 was successfully launched into Leo Earth Orbit on 27th September, 2003. NigeriaSat- 1 is one of the five (5) satellites belonging to Nigeria, Algeria, Turkey, United Kingdom and China being operated in a Disaster Monitoring Constellation (DMC). The launch of NigeriaSat-1 has promoted access to information which has become a strategy for mass socio-economic development, as information underscores all developmental effort be it in education, provision of health services, marketing, construction industry, tourism, defense, etc. As a follow-up to the successful launch of NigeriaSat-1, the government of Nigeria started the implementation of a Nigerian communication satellite (NigcomSat-1) to address the problem of communication which is the greatest drawbacks to the socio-economic development of the country, particularly in the areas of rural telephone, tele-education, tele-medicine, egovernment, e-commerce and real-time monitoring services. NigcomSat-1, which carries 40- hybrid transponders in the C, KU, KA and L bands, has a 15 years life span and coverage of the African continent, Middle East and part of Europe was launched in May 2007. To satisfy geospatial data needs in sectors such as survey

Development, Validation, and Potential Enhancements to the Second-Generation Operational Aerosol Product at the National Environmental Satellite, Data, and Information Service of the National Oceanic and Atmospheric Administration

Science.gov (United States)

Stowe, Larry L.; Ignatov, Alexander M.; Singh, Ramdas R.

1997-01-01

A revised (phase 2) single-channel algorithm for aerosol optical thickness, tau(sup A)(sub SAT), retrieval over oceans from radiances in channel 1 (0.63 microns) of the Advanced Very High Resolution Radiometer (AVHRR) has been implemented at the National Oceanic and Atmospheric Administration's National Environmental Satellite Data and Information Service for the NOAA 14 satellite launched December 30, 1994. It is based on careful validation of its operational predecessor (phase 1 algorithm), implemented for NOAA 14 in 1989. Both algorithms scale the upward satellite radiances in cloud-free conditions to aerosol optical thickness using an updated radiative transfer model of the ocean and atmosphere. Application of the phase 2 algorithm to three matchup Sun-photometer and satellite data sets, one with NOAA 9 in 1988 and two with NOAA 11 in 1989 and 1991, respectively, show systematic error is less than 10%, with a random error of sigma(sub tau) approx. equal 0.04. First results of tau(sup A)(sub SAT) retrievals from NOAA 14 using the phase 2 algorithm, and from checking its internal consistency, are presented. The potential two-channel (phase 3) algorithm for the retrieval of an aerosol size parameter, such as the Junge size distribution exponent, by adding either channel 2 (0.83 microns) from the current AVHRR instrument, or a 1.6-microns channel to be available on the Tropical Rainfall Measurement Mission and the NOAA-KLM satellites by 1997 is under investigation. The possibility of using this additional information in the retrieval of a more accurate estimate of aerosol optical thickness is being explored.

47 CFR 25.260 - Time sharing between DoD meteorological satellite systems and non-voice, non-geostationary...

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Time sharing between DoD meteorological satellite systems and non-voice, non-geostationary satellite systems in the 400.15-401 MHz band. 25.260 Section 25.260 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES...

Environmental Testing Campaign and Verification of Satellite Deimos-2 at INTA

Science.gov (United States)

Hernandez, Daniel; Vazquez, Mercedes; Anon, Manuel; Olivo, Esperanza; Gallego, Pablo; Morillo, Pablo; Parra, Javier; Capraro; Luengo, Mar; Garcia, Beatriz; Villacorta, Pablo

2014-06-01

In this paper the environmental test campaign and verification of the DEIMOS-2 (DM2) satellite will be presented and described. DM2 will be ready for launch in 2014.Firstly, a short description of the satellite is presented, including its physical characteristics and intended optical performances. DEIMOS-2 is a LEO satellite for earth observation that will provide high resolution imaging services for agriculture, civil protection, environmental issues, disasters monitoring, climate change, urban planning, cartography, security and intelligence.Then, the verification and test campaign carried out on the SM and FM models at INTA is described; including Mechanical test for the SM and Climatic, Mechanical and Electromagnetic Compatibility tests for the FM. In addition, this paper includes Centre of Gravity and Moment of Inertia measurements for both models, and other verification activities carried out in order to ensure satellite's health during launch and its in orbit performance.

Time: A Critical Parameter in Satellite Navigation and Positioning ...

African Journals Online (AJOL)

The applications of space-borne satellites are increasing in many aspects of human endeavours; the most among them being the provision of guaranteed access to users of precise time and location services. An investigation was therefore carried out through a review process mechanism to determine the orbit parameter ...

Simulation and Analysis of Autonomous Time Synchronization Based on Asynchronism Two-way Inter-satellite Link

Science.gov (United States)

Fang, L.; Yang, X. H.; Sun, B. Q.; Qin, W. J.; Kong, Y.

2013-09-01

The measurement of the inter-satellite link is one of the key techniques in the autonomous operation of satellite navigation system. Based on the asynchronism inter-satellite two-way measurement mode in GPS constellation, the reduction formula of the inter-satellite time synchronization is built in this paper. Moreover, the corrective method of main systematic errors is proposed. Inter-satellite two-way time synchronization is simulated on the basis of IGS (International GNSS Service) precise ephemeris. The impacts of the epoch domestication of asynchronism inter-satellite link pseudo-range, the initial orbit, and the main systematic errors on satellite time synchronization are analyzed. Furthermore, the broadcast clock error of each satellite is calculated by the ``centralized'' inter-satellite autonomous time synchronization. Simulation results show that the epoch domestication of asynchronism inter-satellite link pseudo-range and the initial orbit have little impact on the satellite clock errors, and thus they needn't be taken into account. The errors caused by the relativistic effect and the asymmetry of path travel have large impact on the satellite clock errors. These should be corrected with theoretical formula. Compared with the IGS precise clock error, the root mean square of the broadcast clock error of each satellite is about 0.4 ns.

Video Streaming Transfer in a Smart Satellite Mobile Environment

OpenAIRE

Celandroni, Nedo; Davoli, Franco; Ferro, Erina; Gotta, Alberto

2009-01-01

In the near future, transportation media are likely to become "smart spaces", where sophisticated services are offered to the passengers. Among such services, we concentrate on video streaming provided on buses that move in urban, suburban, or highway environments. A contents' source utilizes a satellite DVB-S2 link for transmitting video streams to a bus, which, in its turn, relays it to its passengers' devices. A bus works in a smart mode taking advantage of the knowledge of the exact point...

Evaluating the Peruvian Rural Communication Services Project.

Science.gov (United States)

Mayo, John

1988-01-01

Reviews the Peruvian Rural Communication Services (PRCS) Project and outlines selected findings. Topics discussed include a brief description of Peru's economic and social conditions; satellite communication systems; audio teleconferencing; telephone service; planning and administration; research design features; data collection; and project…

A European Land Mobile Satellite System via EMS

Science.gov (United States)

Ananasso, Fulvio; Mistretta, Ignazio

1991-10-01

The paper analyzes the technical and market issues that influence the strategy of implementation of a Land Mobile Satellite System via the payload EMS (European Mobile System) embarked on ITALSAT F-2. The final goal is to determine services, network architecture, and added value chain that make LMSS via EMS profitable for a typical telecommunication company.

Effect of Ionosphere on Geostationary Communication Satellite Signals

Science.gov (United States)

Erdem, Esra; Arikan, Feza; Gulgonul, Senol

2016-07-01

ionosphere using IRI-Plas-G software. One of the outstanding features of IONOLAB-RAY is the opportunity of Global Ionospheric Map-Total Electron Content (GIM-TEC) assimilation. This feature enables more realistic representation of ionosphere, especially for the times when ionosphere deviates from the generalized models, such as during geomagnetic storms. This feature is critical to examine the effect of ionosphere on satellite signals under ionospheric storm conditions. In this study TURKSAT satellite data is used to compare the results of IONOLAB-RAY and evaluate the effect of ionosphere. TURKSAT is one of the world's leading companies providing all sorts of satellite communications through the satellites of TURKSAT as well as the other satellites. Providing services for voice, data, internet, TV, and radio broadcasting through the satellites across a wide area extending from Europe to Asia. The latest satellite of TURKSAT, namely Turksat 4B was launched on October 2015, before that various versions of TURKSAT satellites are launched since 1994. In the future enlargement of broadcasting area towards equatorial region is aimed, where the ionospheric anomalies and storms are highly expected. In the future this study can be applied to the satellite signals in equatorial regions and effects of ionosphere especially under storm conditions can be discussed. This study is supported by TUBITAK 114E541, 115E915 and Joint TUBITAK 114E092 and AS CR 14/001 projects.

Composite Broadcasting and Ranging via a Satellite Dual-Frequency MPPSK System

Directory of Open Access Journals (Sweden)

Yu Yao

2013-01-01

Full Text Available Since digital video broadcasting via satellite (DVB-S signals are “inefficient”, regarding the amount of information they convey on the bandwidth they occupy, a joint broadcasting and ranging system would constitute a unique platform for future digital video broadcasting satellite services effecting the essential tasks of satellite navigation system and direct to home (DTH services, in terms of both spectrum efficiency and cost effectiveness. In this paper, the design of dual frequency M-ary position phase shift keying (MPPSK system which is suitable for, respectively, performing both data transmission and range measurement is proposed. The approach is based on MPPSK modulation waveforms utilized in digital video broadcasting. In particular, requirements that allow for employing such signals for range measurements with high accuracy and high range are investigated. Also, the relationship between the frequency difference of dual frequency MPPSK system and range accuracy is discussed. Moreover, the selection of MPPSK modulation parameter for data rate and ranging is considered. In addition to theoretical considerations, the paper presents system simulations and measurement results of new systems, demonstrating the high spectral utilization of integrated broadcasting and ranging applications.

Combining airborne and satellite remote sensing programs to repress illegal oil discharges in restricted sea areas

International Nuclear Information System (INIS)

Price, M.

2005-01-01

An airborne surveillance program has been conducted over the Belgian part of the North Sea since 1991. The role of the program is to detect infringements on the Marpol Convention via remote sensing, and to take legal action against polluters through the use of recorded observations. Although Belgium has a restricted sea area of about 3,500 km with no fixed offshore oil installations, a pollution risk is constantly present due to 2 dense traffic separation schemes close to the shoreline. The Belgian marine areas and adjacent waters are regularly scanned with a Side Looking Airborne Radar (SLAR) on board a remote sensing aircraft. This paper describes an evaluation trial that the Belgian Management Unit of the North Sea Mathematical Models (MUMM) joined in 2004, together with various agencies from the United Kingdom, Germany and the Netherlands. The trial consists of a cost-sharing satellite service for oil detection with ENVISAT ASAR data. The trial was co-funded by the European Space Agency (ESA) and run by Kongsberg Satellite Services. MUMM's objective was to evaluate the effectiveness and operational character of satellite services for detecting oil spills at sea. The results of the 3 month trial have indicated that aerial remote sensing for the detection of illegal oil discharges at sea increases the chances of catching polluters more efficiently, with improved chances of evidence collecting. It was concluded that when various services are integrated and strict operational conditions are met, satellite services may prove to be valuable in restricted, very densely navigated national waters that are easily reached by airborne means. 12 refs., 8 tabs., 3 figs

Competition in Telecoms-Implications for Universal Service and Employment

OpenAIRE

Petrazzini, Ben A.

1996-01-01

The author argues that competition in domestic telecommunications markets promotes both universal service and employment in developing countries. Thus, incumbent monopoly operators should be reformed. And since incumbents are subject to increasingly fierce international competition from callback services, Internet phone services, mobile satellite services, and global operators, this reform ...

Validation of Galileo orbits using SLR with a focus on satellites launched into incorrect orbital planes

Science.gov (United States)

Sośnica, Krzysztof; Prange, Lars; Kaźmierski, Kamil; Bury, Grzegorz; Drożdżewski, Mateusz; Zajdel, Radosław; Hadas, Tomasz

2018-02-01

The space segment of the European Global Navigation Satellite System (GNSS) Galileo consists of In-Orbit Validation (IOV) and Full Operational Capability (FOC) spacecraft. The first pair of FOC satellites was launched into an incorrect, highly eccentric orbital plane with a lower than nominal inclination angle. All Galileo satellites are equipped with satellite laser ranging (SLR) retroreflectors which allow, for example, for the assessment of the orbit quality or for the SLR-GNSS co-location in space. The number of SLR observations to Galileo satellites has been continuously increasing thanks to a series of intensive campaigns devoted to SLR tracking of GNSS satellites initiated by the International Laser Ranging Service. This paper assesses systematic effects and quality of Galileo orbits using SLR data with a main focus on Galileo satellites launched into incorrect orbits. We compare the SLR observations with respect to microwave-based Galileo orbits generated by the Center for Orbit Determination in Europe (CODE) in the framework of the International GNSS Service Multi-GNSS Experiment for the period 2014.0-2016.5. We analyze the SLR signature effect, which is characterized by the dependency of SLR residuals with respect to various incidence angles of laser beams for stations equipped with single-photon and multi-photon detectors. Surprisingly, the CODE orbit quality of satellites in the incorrect orbital planes is not worse than that of nominal FOC and IOV orbits. The RMS of SLR residuals is even lower by 5.0 and 1.5 mm for satellites in the incorrect orbital planes than for FOC and IOV satellites, respectively. The mean SLR offsets equal -44.9, -35.0, and -22.4 mm for IOV, FOC, and satellites in the incorrect orbital plane. Finally, we found that the empirical orbit models, which were originally designed for precise orbit determination of GNSS satellites in circular orbits, provide fully appropriate results also for highly eccentric orbits with variable linear

Evaluation of Future Internet Technologies for Processing and Distribution of Satellite Imagery

Science.gov (United States)

Becedas, J.; Perez, R.; Gonzalez, G.; Alvarez, J.; Garcia, F.; Maldonado, F.; Sucari, A.; Garcia, J.

2015-04-01

Satellite imagery data centres are designed to operate a defined number of satellites. For instance, difficulties when new satellites have to be incorporated in the system appear. This occurs because traditional infrastructures are neither flexible nor scalable. With the appearance of Future Internet technologies new solutions can be provided to manage large and variable amounts of data on demand. These technologies optimize resources and facilitate the appearance of new applications and services in the traditional Earth Observation (EO) market. The use of Future Internet technologies for the EO sector were validated with the GEO-Cloud experiment, part of the Fed4FIRE FP7 European project. This work presents the final results of the project, in which a constellation of satellites records the whole Earth surface on a daily basis. The satellite imagery is downloaded into a distributed network of ground stations and ingested in a cloud infrastructure, where the data is processed, stored, archived and distributed to the end users. The processing and transfer times inside the cloud, workload of the processors, automatic cataloguing and accessibility through the Internet are evaluated to validate if Future Internet technologies present advantages over traditional methods. Applicability of these technologies is evaluated to provide high added value services. Finally, the advantages of using federated testbeds to carry out large scale, industry driven experiments are analysed evaluating the feasibility of an experiment developed in the European infrastructure Fed4FIRE and its migration to a commercial cloud: SoftLayer, an IBM Company.

Orbit and clock determination of BDS regional navigation satellite system based on IGS M-GEX and WHU BETS tracking network

Science.gov (United States)

GENG, T.; Zhao, Q.; Shi, C.; Shum, C.; Guo, J.; Su, X.

2013-12-01

BeiDou Navigation Satellite System (BDS) began to provide the regional open service on December 27th 2012 and will provide the global open service by the end of 2020. Compared to GPS, the space segment of BDS Regional System consists of 5 Geostationary Earth Orbit satellites (GEO), 5 Inclined Geosynchronous Orbit satellites (IGSO) and 4 Medium Earth orbit (MEO) satellites. Since 2011, IGS Multiple-GNSS Experiment (M-GEX) focuses on tracking the newly available GNSS signals. This includes all signals from the modernized satellites of the GPS and GLONASS systems, as well as signals of the BDS, Galileo and QZSS systems. Up to now, BDS satellites are tracked by around 25 stations with a variety of different antennas and receivers from different GNSS manufacture communities in M-GEX network. Meanwhile, there are 17 stations with Unicore Communications Incorporation's GPS/BDS receivers in BeiDou Experimental Tracking Stations (BETS) network by Wuhan University. In addition, 5 BDS satellites have been tracking by the International Laser Ranging Service (ILRS). BDS performance is expected to be further studied by the GNSS communities. Following an introduction of the BDS system and above different tracking network, this paper discusses the achieved BDS characterization and performance assessment. Firstly, the BDS signal and measurement quality are analyzed with different antennas and receivers in detail compared to GPS. This includes depth of coverage for satellite observation, carrier-to-noise-density ratios, code noise and multipath, carrier phase errors. Secondly, BDS Precise Orbit Determination (POD) is processed. Different arc lengths and sets of orbit parameters are tested using Position And Navigation Data Analysis software (PANDA) which is developed at the Wuhan University. GEO, IGSO and MEO satellites orbit quality will be assessed using overlap comparison, 2-day orbit fit and external validations with Satellite Laser Range (SLR). Then BDS satellites are equipped

Current State of Art of Satellite Altimetry

Directory of Open Access Journals (Sweden)

Łyszkowicz Adam

2017-12-01

Full Text Available One of the fundamental problems of modern geodesy is precise definition of the gravitational field and its changes in time. This is essential in positioning and navigation, geo-physics, geodynamics, oceanography and other sciences related to the climate and Earth’s environment. One of the major sources of gravity data is satellite altimetry that provides gravity data with almost 75% surface of the Earth. Satellite altimetry also provides data to study local, regional and global geophysical processes, the geoid model in the areas of oceans and seas. This technique can be successfully used to study the ocean mean dynamic topography. The results of the investigations and possible products of altimetry will provide a good material for the GGOS (Global Geodetic Observing System and institutions of IAS (International Altimetry Service.

Web Based Rapid Mapping of Disaster Areas using Satellite Images, Web Processing Service, Web Mapping Service, Frequency Based Change Detection Algorithm and J-iView

Science.gov (United States)

Bandibas, J. C.; Takarada, S.

2013-12-01

Timely identification of areas affected by natural disasters is very important for a successful rescue and effective emergency relief efforts. This research focuses on the development of a cost effective and efficient system of identifying areas affected by natural disasters, and the efficient distribution of the information. The developed system is composed of 3 modules which are the Web Processing Service (WPS), Web Map Service (WMS) and the user interface provided by J-iView (fig. 1). WPS is an online system that provides computation, storage and data access services. In this study, the WPS module provides online access of the software implementing the developed frequency based change detection algorithm for the identification of areas affected by natural disasters. It also sends requests to WMS servers to get the remotely sensed data to be used in the computation. WMS is a standard protocol that provides a simple HTTP interface for requesting geo-registered map images from one or more geospatial databases. In this research, the WMS component provides remote access of the satellite images which are used as inputs for land cover change detection. The user interface in this system is provided by J-iView, which is an online mapping system developed at the Geological Survey of Japan (GSJ). The 3 modules are seamlessly integrated into a single package using J-iView, which could rapidly generate a map of disaster areas that is instantaneously viewable online. The developed system was tested using ASTER images covering the areas damaged by the March 11, 2011 tsunami in northeastern Japan. The developed system efficiently generated a map showing areas devastated by the tsunami. Based on the initial results of the study, the developed system proved to be a useful tool for emergency workers to quickly identify areas affected by natural disasters.

Efficient medium access control protocol for geostationary satellite systems

Institute of Scientific and Technical Information of China (English)

王丽娜; 顾学迈

2004-01-01

This paper proposes an efficient medium access control (MAC) protocol based on multifrequency-time division multiple access (MF-TDMA) for geostationary satellite systems deploying multiple spot-beams and onboard processing,which uses a method of random reservation access with movable boundaries to dynamically request the transmission slots and can transmit different types of traffic. The simulation results have shown that our designed MAC protocol can achieve a high bandwidth utilization, while providing the required quality of service (QoS) for each class of service.

Use of satellite images for the monitoring of water systems

Science.gov (United States)

Hillebrand, Gudrun; Winterscheid, Axel; Baschek, Björn; Wolf, Thomas

2015-04-01

Satellite images are a proven source of information for monitoring ecological indicators in coastal waters and inland river systems. This potential of remote sensing products was demonstrated by recent research projects (e.g. EU-funded project Freshmon - www.freshmon.eu) and other activities by national institutions. Among indicators for water quality, a particular focus was set on the temporal and spatial dynamics of suspended particulate matter (SPM) and Chlorophyll-a (Chl-a). The German Federal Institute of Hydrology (BfG) was using the Weser and Elbe estuaries as test cases to compare in-situ measurements with results obtained from a temporal series of automatically generated maps of SPM distributions based on remote sensing data. Maps of SPM and Chl-a distributions in European inland rivers and alpine lakes were generated by the Freshmon Project. Earth observation based products are a valuable source for additional data that can well supplement in-situ monitoring. For 2015, the BfG and the Institute for Lake Research of the State Institute for the Environment, Measurements and Nature Conservation of Baden-Wuerttemberg, Germany (LUBW) are in the process to start implementing an operational service for monitoring SPM and Chl-a based on satellite images (Landsat 7 & 8, Sentinel 2, and if required other systems with higher spatial resolution, e.g. Rapid Eye). In this 2-years project, which is part of the European Copernicus Programme, the operational service will be set up for - the inland rivers of Rhine and Elbe - the North Sea estuaries of Elbe, Weser and Ems. Furthermore - Lake Constance and other lakes located within the Federal State of Baden-Wuerttemberg. In future, the service can be implemented for other rivers and lakes as well. Key feature of the project is a data base that holds the stock of geo-referenced maps of SPM and Chl-a distributions. Via web-based portals (e.g. GGInA - geo-portal of the BfG; UIS - environmental information system of the

Leveraging the NPS Femto Satellite for Alternative Satellite Communication Networks

Science.gov (United States)

2017-09-01

programmed for eventual integration with the Iridium Network , which is then tested. C. THESIS ORGANIZATION The thesis addresses these questions...NPS FEMTO SATELLITE FOR ALTERNATIVE SATELLITE COMMUNICATION NETWORKS by Faisal S. Alshaya September 2017 Co-Advisors: Steven J. Iatrou...TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE LEVERAGING THE NPS FEMTO SATELLITE FOR ALTERNATIVE SATELLITE COMMUNICATION NETWORKS 5

Development of a demand assignment/TDMA system for international business satellite communications

Science.gov (United States)

Nohara, Mitsuo; Takeuchi, Yoshio; Takahata, Fumio; Hirata, Yasuo; Yamazaki, Yoshiharu

An experimental IBS (international business satellite) communications system based on a demand assignment and TDMA (time-division multiple-access) operation has been developed. The system utilizes a limited satellite resource efficiently and provides various kinds of ISDN services totally. A discussion is presented of the IBS network configurations suitable to international communications and describes the developed communications system from the viewpoint of the hardware and software implementation. The performance in terms of the transmission quality and call processing is also demonstrated.

Use of negotiated rulemaking in developing technical rules for low-Earth orbit mobile satellite systems

Science.gov (United States)

Taylor, Leslie A.

Technical innovations have converged with the exploding market demand for mobile telecommunications to create the impetus for low-earth orbit (LEO) communications satellite systems. The so-called 'Little LEO's' propose use of VHF and UHF spectrum to provide position - location and data messaging services. The so-called 'Big LEO's' propose to utilize the RDSS bands to provide voice and data services. In the United States, several applications were filed with the U.S. Federal Communications Commission (FCC) to construct and operate these mobile satellite systems. To enable the prompt introduction of such new technology services, the FCC is using innovative approaches to process the applications. Traditionally, when the FCC is faced with 'mutually exclusive' applications, e.g. a grant of one would preclude a grant of the others, it uses selection mechanisms such as comparative hearings or lotteries. In the case of the LEO systems, the FCC has sought to avoid these time-consuming approaches by using negotiated rulemakings. The FCC's objective is to enable the multiple applicants and other interested parties to agree on technical and service rules which will enable the grant of all qualified applications. With regard to the VHF/UHF systems, the Advisory Committee submitted a consensus report to the FCC. The process for the systems operating in the bands above 1 GHz involved more parties and more issues but still provided the FCC useful technical information to guide the adoption of rules for the new mobile satellite service.

Meteorological satellite systems

CERN Document Server

Tan, Su-Yin

2014-01-01

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

GEARS: An Enterprise Architecture Based On Common Ground Services

Science.gov (United States)

Petersen, S.

2014-12-01

Earth observation satellites collect a broad variety of data used in applications that range from weather forecasting to climate monitoring. Within NOAA the National Environmental Satellite Data and Information Service (NESDIS) supports these applications by operating satellites in both geosynchronous and polar orbits. Traditionally NESDIS has acquired and operated its satellites as stand-alone systems with their own command and control, mission management, processing, and distribution systems. As the volume, velocity, veracity, and variety of sensor data and products produced by these systems continues to increase, NESDIS is migrating to a new concept of operation in which it will operate and sustain the ground infrastructure as an integrated Enterprise. Based on a series of common ground services, the Ground Enterprise Architecture System (GEARS) approach promises greater agility, flexibility, and efficiency at reduced cost. This talk describes the new architecture and associated development activities, and presents the results of initial efforts to improve product processing and distribution.

Optical intersatellite links - Application to commercial satellite communications

Science.gov (United States)

Paul, D.; Faris, F.; Garlow, R.; Inukai, T.; Pontano, B.; Razdan, R.; Ganz, Aura; Caudill, L.

1992-01-01

Application of optical intersatellite links for commercial satellite communications services is addressed in this paper. The feasibility of commercialization centers around basic issues such as the need and derived benefits, implementation complexity and overall cost. In this paper, commercialization of optical ISLs is assessed in terms of the services provided, systems requirements and feasibility of appropriate technology. Both long- and short-range ISLs for GEO-GEO, GEO-LEO and LEO applications are considered. Impact of systems requirements on the payload design and use of advanced technology in reducing its mass, power, and volume requirements are discussed.

Satellite -Based Networks for U-Health & U-Learning

Science.gov (United States)

Graschew, G.; Roelofs, T. A.; Rakowsky, S.; Schlag, P. M.

2008-08-01

The use of modern Information and Communication Technologies (ICT) as enabling tools for healthcare services (eHealth) introduces new ways of creating ubiquitous access to high-level medical care for all, anytime and anywhere (uHealth). Satellite communication constitutes one of the most flexible methods of broadband communication offering high reliability and cost-effectiveness of connections meeting telemedicine communication requirements. Global networks and the use of computers for educational purposes stimulate and support the development of virtual universities for e-learning. Especially real-time interactive applications can play an important role in tailored and personalised services.

Global Precipitation Measurement (GPM) Mission Products and Services at the NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC)

Science.gov (United States)

Liu, Zhong; Ostrenga, D.; Vollmer, B.; Deshong, B.; Greene, M.; Teng, W.; Kempler, S. J.

2015-01-01

On February 27, 2014, the NASA Global Precipitation Measurement (GPM) mission was launched to provide the next-generation global observations of rain and snow (http:pmm.nasa.govGPM). The GPM mission consists of an international network of satellites in which a GPM Core Observatory satellite carries both active and passive microwave instruments to measure precipitation and serve as a reference standard, to unify precipitation measurements from a constellation of other research and operational satellites. The NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) hosts and distributes GPM data within the NASA Earth Observation System Data Information System (EOSDIS). The GES DISC is home to the data archive for the GPM predecessor, the Tropical Rainfall Measuring Mission (TRMM). Over the past 16 years, the GES DISC has served the scientific as well as other communities with TRMM data and user-friendly services. During the GPM era, the GES DISC will continue to provide user-friendly data services and customer support to users around the world. GPM products currently and to-be available include the following: 1. Level-1 GPM Microwave Imager (GMI) and partner radiometer products. 2. Goddard Profiling Algorithm (GPROF) GMI and partner products. 3. Integrated Multi-satellitE Retrievals for GPM (IMERG) products. (early, late, and final)A dedicated Web portal (including user guides, etc.) has been developed for GPM data (http:disc.sci.gsfc.nasa.govgpm). Data services that are currently and to-be available include Google-like Mirador (http:mirador.gsfc.nasa.gov) for data search and access; data access through various Web services (e.g., OPeNDAP, GDS, WMS, WCS); conversion into various formats (e.g., netCDF, HDF, KML (for Google Earth), ASCII); exploration, visualization, and statistical online analysis through Giovanni (http:giovanni.gsfc.nasa.gov); generation of value-added products; parameter and spatial subsetting; time aggregation; regridding; data

Global Precipitation Measurement (GPM) Mission Products and Services at the NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC)

Science.gov (United States)

Ostrenga, D.; Liu, Z.; Vollmer, B.; Teng, W. L.; Kempler, S. J.

2014-12-01

On February 27, 2014, the NASA Global Precipitation Measurement (GPM) mission was launched to provide the next-generation global observations of rain and snow (http://pmm.nasa.gov/GPM). The GPM mission consists of an international network of satellites in which a GPM "Core Observatory" satellite carries both active and passive microwave instruments to measure precipitation and serve as a reference standard, to unify precipitation measurements from a constellation of other research and operational satellites. The NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) hosts and distributes GPM data within the NASA Earth Observation System Data Information System (EOSDIS). The GES DISC is home to the data archive for the GPM predecessor, the Tropical Rainfall Measuring Mission (TRMM). Over the past 16 years, the GES DISC has served the scientific as well as other communities with TRMM data and user-friendly services. During the GPM era, the GES DISC will continue to provide user-friendly data services and customer support to users around the world. GPM products currently and to-be available include the following: Level-1 GPM Microwave Imager (GMI) and partner radiometer products Goddard Profiling Algorithm (GPROF) GMI and partner products Integrated Multi-satellitE Retrievals for GPM (IMERG) products (early, late, and final) A dedicated Web portal (including user guides, etc.) has been developed for GPM data (http://disc.sci.gsfc.nasa.gov/gpm). Data services that are currently and to-be available include Google-like Mirador (http://mirador.gsfc.nasa.gov/) for data search and access; data access through various Web services (e.g., OPeNDAP, GDS, WMS, WCS); conversion into various formats (e.g., netCDF, HDF, KML (for Google Earth), ASCII); exploration, visualization, and statistical online analysis through Giovanni (http://giovanni.gsfc.nasa.gov); generation of value-added products; parameter and spatial subsetting; time aggregation; regridding

Boomerang Satellites

Science.gov (United States)

Hesselbrock, Andrew; Minton, David A.

2017-10-01

We recently reported that the orbital architecture of the Martian environment allows for material in orbit around the planet to ``cycle'' between orbiting the planet as a ring, or as coherent satellites. Here we generalize our previous analysis to examine several factors that determine whether satellites accreting at the edge of planetary rings will cycle. In order for the orbiting material to cycle, tidal evolution must decrease the semi-major axis of any accreting satellites. In some systems, the density of the ring/satellite material, the surface mass density of the ring, the tidal parameters of the system, and the rotation rate of the primary body contribute to a competition between resonant ring torques and tidal dissipation that prevent this from occurring, either permanently or temporarily. Analyzing these criteria, we examine various bodies in our solar system (such as Saturn, Uranus, and Eris) to identify systems where cycling may occur. We find that a ring-satellite cycle may give rise to the current Uranian ring-satellite system, and suggest that Miranda may have formed from an early, more massive Uranian ring.

Public Service Telecommunications: PEACESAT.

Science.gov (United States)

Okamura, Norman H.; Mukaida, Lori Van Dusen

1996-01-01

Describes the Pan-Pacific Education and Communication Experiments by Satellite (PEACESAT), a public service telecommunication program developed to facilitate the use of telecommunications and information technologies. Highlights include the historical development; digital capabilities; cooperation and collaboration with users, government, and…

International Telecommunications Satellite Organization (INTELSAT) Agreement Between the United States of American and Other Governments and Operating Agreement.

Science.gov (United States)

Department of State, Washington, DC.

The INTELSAT (International Telecommunications Satellite) agreement was reached because of the desirability of continuing the development of a telecommunications satellite system. INTELSAT's aim was to achieve a single global commercial system as part of an improved global telecommunications network which will provide expanded services to all…

Video Streaming Transfer in a Smart Satellite Mobile Environment

Directory of Open Access Journals (Sweden)

Nedo Celandroni

2009-01-01

satellite link for transmitting video streams to a bus, where they are relayed to passengers' devices. We say that a bus works in smart mode if it takes advantage of the knowledge of the exact points where fixed obstacles will prevent receiving the satellite signal for a certain time period. This information is sent to the hub via a return channel. The hub, in its turn, suspends the transmissions to that specific bus for the given time interval, thus avoiding information losses and unnecessary bandwidth occupation. Buffering video packets, without any quality of service (QoS degradation, seamlessly compensates channel blockages up to a given duration. We determine the most appropriate transmission parameters for video streaming with good video QoS in a mobile satellite environment; moreover, we evaluate how “smart” the system can be in terms of bandwidth saving, by comparing it with the situation where the bus does not exploit the description of its route, still maintaining the same QoS requirements.

Debris mitigation measures by satellite design and operational methods - Findings from the DLR space debris End-to-End Service

Science.gov (United States)

Sdunnus, H.; Beltrami, P.; Janovsky, R.; Koppenwallner, G.; Krag, H.; Reimerdes, H.; Schäfer, F.

Debris Mitigation has been recognised as an issue to be addressed by the space faring nations around the world. Currently, there are various activities going on, aiming at the establishment of debris mitigation guidelines on various levels, reaching from the UN down to national space agencies. Though guidelines established on the national level already provide concrete information how things should be done (rather that specifying what should be done or providing fundamental principles) potential users of the guidelines will still have the need to explore the technical, management, and financial implications of the guidelines for their projects. Those questions are addressed by the so called "Space Debris End-to-End Service" project, which has been initiated as a national initiative of the German Aerospace Centre (DLR). Based on a review of already existing mitigation guidelines or guidelines under development and following an identification of needs from a circle of industrial users the "End-to-End Service Gu idelines" have been established for designer and operators of spacecraft. The End-to-End Service Guidelines are based on requirements addressed by the mitigation guidelines and provide recommendations how and when the technical consideration of the mitigation guidelines should take place. By referencing requirements from the mitigation guidelines, the End-to-End Service Guidelines address the consideration of debris mitigation measures by spacecraft design and operational measures. This paper will give an introduction to the End-to-End Service Guidelines. It will focus on the proposals made for mitigation measures by the S/C system design, i.e. on protective design measures inside the spacecraft and on design measures, e.g. innovative protective (shielding) systems. Furthermore, approaches on the analytical optimisation of protective systems will be presented, aiming at the minimisation of shield mass under conservation of the protective effects. On the

47 CFR 25.158 - Consideration of GSO-like satellite applications.

Science.gov (United States)

2010-10-01

... directional antennas. Examples of GSO-like satellite systems are those which use earth stations with antennas... contiguous bandwidth in both the uplink and downlink band. Each licensee's bandwidth selection shall not... selection. (e) Services offered pursuant to a GSO-like license in a frequency band granted before the...

A comparison of Frequency Domain Multiple Access (FDMA) and Time Domain Multiple Access (TDMA) approaches to satellite service for low data rate Earth stations

Science.gov (United States)

Stevens, G.

1983-01-01

A technological and economic assessment is made of providing low data rate service to small earth stations by satellite at Ka-band. Various Frequency Domain Multiple Access (FDMA) and Time Domain Multiple Access (TDMA) scenarios are examined and compared on the basis of cost to the end user. Very small stations (1 to 2 meters in diameter) are found not to be viable alternatives to available terrestrial services. However, medium size (3 to 5 meters) earth stations appear to be very competitive if a minimum throughput of about 1.5 Mbs is maintained. This constrains the use of such terminals to large users and shared use by smaller users. No advantage was found to the use of FDMA. TDMA had a slight advantage from a total system viewpoint and a very significant advantage in the space segment (about 1/3 the required payload weight for an equivalent capacity).

Operational Estimation of Accumulated Precipitation using Satellite Observation, by Eumetsat Satellite Application facility in Support to Hydrology (H-SAF Consortium).

Science.gov (United States)

di Diodato, A.; de Leonibus, L.; Zauli, F.; Biron, D.; Melfi, D.

2009-04-01

Operational Estimation of Accumulated Precipitation using Satellite Observation, by Eumetsat Satellite Application facility in Support to Hydrology (H-SAF Consortium). Cap. Attilio DI DIODATO(*), T.Col. Luigi DE LEONIBUS(*), T.Col Francesco ZAULI(*), Cap. Daniele BIRON(*), Ten. Davide Melfi(*) Satellite Application Facilities (SAFs) are specialised development and processing centres of the EUMETSAT Distributed Ground Segment. SAFs process level 1b data from meteorological satellites (geostationary and polar ones) in conjunction with all other relevant sources of data and appropriate models to generate services and level 2 products. Each SAF is a consortium of EUMETSAT European partners lead by a host institute responsible for the management of the complete SAF project. The Meteorological Service of Italian Air Force is the host Institute for the Satellite Application Facility on Support to Operational Hydrology and Water Management (H-SAF). HSAF has the commitment to develop and to provide, operationally after 2010, products regarding precipitation, soil moisture and snow. HSAF is going to provide information on error structure of its products and validation of the products via their impacts into Hydrological models. To that purpose it has been structured a specific subgroups. Accumulated precipitation is computed by temporal integration of the instantaneous rain rate achieved by the blended LEO/MW and GEO/IR precipitation rate products generated by Rapid Update method available every 15 minutes. The algorithm provides four outputs, consisting in accumulated precipitation in 3, 6, 12 and 24 hours, delivered every 3 hours at the synoptic hours. These outputs are our precipitation background fields. Satellite estimates can cover most of the globe, however, they suffer from errors due to lack of a direct relationship between observation parameters and precipitation, the poor sampling and algorithm imperfections. For this reason the 3 hours accumulated precipitation is

Research-related intercultural higher education in satellite geodesy

Science.gov (United States)

Mayer, M.; Heck, B.; Krueger, C. P.

2009-04-01

In order to improve the education of young researchers (master degree, PhD, PostDocs) a cooperation between the Department of Geomatics (DGEOM), Federal University of Paraná (UFPR), Curitiba (Brazil) and the Geodetic Institute (GIK), University Karlsruhe (TH), Karlsruhe (Germany) was established which now exists since more than five years. The joint venture is actually called "PROBRAL: Precise positioning and height determination by means of GPS: Modeling of errors and transformation into physical heights" and focuses on research and education within the field of satellite geodesy. PROBRAL is funded by the Brazilian academic exchange service CAPES and the German academic exchange service DAAD. The geodetic aim of the research project is to validate and improve the quality of 3d positions derived from observations related to satellite navigation systems like GPS. In order to fulfill this ambitious goal sustainably, research has to be carried out in close cooperation. At the same time, e.g. to guarantee continuous success, a coordinated education has to be ensured. Besides technical education aspects key competences (e.g. language, capacity for teamwork, project management skills) are trained. Within the presentation the lessons which were learned from this project are discussed in detail.

A Web Service Tool (SOAR) for the Dynamic Generation of L1 Grids of Coincident AIRS, AMSU and MODIS Satellite Sounding Radiance Data for Climate Studies

Science.gov (United States)

Halem, M.; Yesha, Y.; Tilmes, C.; Chapman, D.; Goldberg, M.; Zhou, L.

2007-05-01

Three decades of Earth remote sensing from NASA, NOAA and DOD operational and research satellites carrying successive generations of improved atmospheric sounder instruments have resulted in petabytes of radiance data with varying spatial and spectral resolutions being stored at different data archives in various data formats by the respective agencies. This evolution of sounders and the diversities of these archived data sets have led to data processing obstacles limiting the science community from readily accessing and analyzing such long-term climate data records. We address this problem by the development of a web based Service Oriented Atmospheric Radiance (SOAR) system built on the SOA paradigm that makes it practical for the science community to dynamically access, manipulate and generate long term records of L1 pre-gridded sounding radiances of coincident multi-sensor data for regions specified according to user chosen criteria. SOAR employs a modification of the standard Client Server interactions that allows users to represent themselves directly to the Process Server through their own web browsers. The browser uses AJAX to request Javascript libraries and DHTML interfaces that define the possible client interactions and communicates the SOAP messages to the Process server allowing for dynamic web dialogs with the user to take place on the fly. The Process Server is also connected to an underlying high performance compute cluster and storage system which provides much of the data processing capabilities required to service the client requests. The compute cluster employs optical communications to NOAA and NASA for accessing the data and under the governance of the Process Server invokes algorithms for on-demand spatial, temporal, and spectral gridding. Scientists can choose from a variety of statistical averaging techniques for compositing satellite observed sounder radiances from the AIRS, AMSU or MODIS instruments to form spatial-temporal grids for

Satellite and terrestrial radio positioning techniques a signal processing perspective

CERN Document Server

Dardari, Davide; Falletti, Emanuela

2014-01-01

* The first book to combine satellite and terrestrial positioning techniques - vital for the understanding and development of new technologies * Written and edited by leading experts in the field, with contributors belonging to the European Commission's FP7 Network of Excellence NEWCOM++ Applications to a wide range of fields, including sensor networks, emergency services, military use, location-based billing, location-based advertising, intelligent transportation, and leisure Location-aware personal devices and location-based services have become ever more prominent in the past few years

A digital simulation of message traffic for natural disaster warning communications satellite

Science.gov (United States)

Hein, G. F.; Stevenson, S. M.

1972-01-01

Various types of weather communications are required to alert industries and the general public about the impending occurrence of tornados, hurricanes, snowstorms, floods, etc. A natural disaster warning satellite system has been proposed for meeting the communications requirements of the National Oceanic and Atmospheric Administration. Message traffic for a communications satellite was simulated with a digital computer in order to determine the number of communications channels to meet system requirements. Poisson inputs are used for arrivals and an exponential distribution is used for service.

Research Article Special Issue

African Journals Online (AJOL)

2016-06-15

Jun 15, 2016 ... The research questionnaires were Afrooz Marital Satisfaction Scale (AMSS) ... Marriage is the pillar of a family, so it is defined by legal and ... functioning which determines the structural and organizational characteristics of.

Phillips Laboratory small satellite initiatives

Science.gov (United States)

Lutey, Mark K.; Imler, Thomas A.; Davis, Robert J.

1993-09-01

The Phillips Laboratory Space Experiments Directorate in conjunction with the Air Force Space Test Program (AF STP), Defense Advanced Research and Projects Agency (DARPA) and Strategic Defense Initiative Organization (SDIO), are managing five small satellite program initiatives: Lightweight Exo-Atmospheric Projectile (LEAP) sponsored by SDIO, Miniature Sensor Technology Integration (MSTI) sponsored by SDIO, Technology for Autonomous Operational Survivability (TAOS) sponsored by Phillips Laboratory, TechSat sponsored by SDIO, and the Advanced Technology Standard Satellite Bus (ATSSB) sponsored by DARPA. Each of these spacecraft fulfills a unique set of program requirements. These program requirements range from a short-lived `one-of-a-kind' mission to the robust multi- mission role. Because of these diverging requirements, each program is driven to use a different design philosophy. But regardless of their design, there is the underlying fact that small satellites do not always equate to small missions. These spacecraft with their use of or ability to insert new technologies provide more capabilities and services for their respective payloads which allows the expansion of their mission role. These varying program efforts culminate in an ATSSB spacecraft bus approach that will support moderate size payloads, up to 500 pounds, in a large set of orbits while satisfying the `cheaper, faster, better' method of doing business. This technical paper provides an overview of each of the five spacecraft, focusing on the objectives, payoffs, technologies demonstrated, and program status.

R&D of a Next Generation LEO System for Global Multimedia Mobile Satellite Communications

Science.gov (United States)

Morikawa, E.; Motoyoshi, S.; Koyama, Y.; Suzuki, R.; Yasuda, Y.

2002-01-01

Next-generation LEO System Research Center (NeLS) was formed in the end of 1997 as a research group under the Telecommunications Advancement Organization of Japan, in cooperation with the telecommunications operators, manufacturers, universities and governmental research organization. The aim of this project is to develop new technology for global multimedia mobile satellite communications services with a user data rate around 2Mbps for handy terminals. component of the IMT-2000, and the second generation of the big-LEO systems. In prosecuting this project, two-phase approach, phase 1 and phase 2, is considered. Phase 1 is the system definition and development of key technologies. In Phase 2, we plan to verify the developed technology in Phase 1 on space. From this year we shifted the stage to Phase 2, and are now developing the prototype of on-board communication systems for flight tests, which will be planed at around 2006. The satellite altitude is assumed to be 1200 km in order to reduce the number of satellites, to avoid the Van Allen radiation belts and to increase the minimum elevation angle. Ten of the circular orbits with 55 degree of inclination are selected to cover the earth surface from -70 to 70 degree in latitude. 12 satellites are positioned at regular intervals in each orbit. In this case, the minimum elevation angle from the user terminal can be keep more than 20 degree for the visibility of the satellite, and 15 degree for simultaneous visibility of two satellites. Then, NeLS Research Center was focusing on the development of key technologies as the phase 1 project. Four kinds of key technologies; DBF satellite antenna, optical inter-satellite link system, satellite network technology with on-board ATM switch and variable rate modulation were selected. Satellite Antenna Technology: Development of on-board direct radiating active phased array antenna with digital beam forming technology would be one of the most important breakthroughs for the

Next-Generation NASA Earth-Orbiting Relay Satellites: Fusing Optical and Microwave Communications

Science.gov (United States)

Israel, David J.; Shaw, Harry

2018-01-01

NASA is currently considering architectures and concepts for the generation of relay satellites that will replace the Tracking and Data Relay Satellite (TDRS) constellation, which has been flying since 1983. TDRS-M, the last of the second TDRS generation, launched in August 2017, extending the life of the TDRS constellation beyond 2030. However, opportunities exist to re-engineer the concepts of geosynchronous Earth relay satellites. The needs of the relay satellite customers have changed dramatically over the last 34 years since the first TDRS launch. There is a demand for greater bandwidth as the availability of the traditional RF spectrum for space communications diminishes and the demand for ground station access grows. The next generation of NASA relay satellites will provide for operations that have factored in these new constraints. In this paper, we describe a heterogeneous constellation of geosynchronous relay satellites employing optical and RF communications. The new constellation will enable new optical communications services formed by user-to-space relay, space relay-to-space relay and space relay-to-ground links. It will build upon the experience from the Lunar Laser Communications Demonstration from 2013 and the Laser Communications Relay Demonstration to be launched in 2019.Simultaneous to establishment of the optical communications space segment, spacecraft in the TDRS constellation will be replaced with RF relay satellites with targeted subsets of the TDRS capabilities. This disaggregation of the TDRS service model will allow for flexibility in replenishing the needs of legacy users as well as addition of new capabilities for future users. It will also permit the U.S. government access to launch capabilities such as rideshare and to hosted payloads that were not previously available.In this paper, we also explore how the next generation of Earth relay satellites provides a significant boost in the opportunities for commercial providers to the

Next-Generation NASA Earth-Orbiting Relay Satellites: Fusing Microwave and Optical Communications

Science.gov (United States)

Israel, David J.

2018-01-01

NASA is currently considering architectures and concepts for the generation of relay satellites that will replace the Tracking and Data Relay Satellite (TDRS) constellation, which has been flying since 1983. TDRS-M, the last of the second TDRS generation, launched in August 2017, extending the life of the TDRS constellation beyond 2030. However, opportunities exist to re-engineer the concepts of geosynchronous Earth relay satellites. The needs of the relay satellite customers have changed dramatically over the last 34 years since the first TDRS launch. There is a demand for greater bandwidth as the availability of the traditional RF spectrum for space communications diminishes and the demand for ground station access grows. The next generation of NASA relay satellites will provide for operations that have factored in these new constraints. In this paper, we describe a heterogeneous constellation of geosynchronous relay satellites employing optical and RF communications. The new constellation will enable new optical communications services formed by user-to-space relay, space relay-to-space relay and space relay-to-ground links. It will build upon the experience from the Lunar Laser Communications Demonstration from 2013 and the Laser Communications Relay Demonstration to be launched in 2019.Simultaneous to establishment of the optical communications space segment, spacecraft in the TDRS constellation will be replaced with RF relay satellites with targeted subsets of the TDRS capabilities. This disaggregation of the TDRS service model will allow for flexibility in replenishing the needs of legacy users as well as addition of new capabilities for future users. It will also permit the U.S. government access to launch capabilities such as rideshare and to hosted payloads that were not previously available. In this paper, we also explore how the next generation of Earth relay satellites provides a significant boost in the opportunities for commercial providers to the

Centriolar satellites

DEFF Research Database (Denmark)

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

2015-01-01

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

Development of the European Small Geostationary Satellite SGEO

Science.gov (United States)

Lübberstedt, H.; Schneider, A.; Schuff, H.; Miesner, Th.; Winkler, A.

2008-08-01

The SGEO product portfolio, ranging from Satellite platform delivery up to in-orbit delivery of a turnkey system including satellite and ground control station, is designed for applications ranging from TV Broadcast to multimedia applications, Internet access, mobile or fixed services in a wide range of frequency bands. Furthermore, Data Relay missions such as the European Data Relay Satellite (EDRS) as well as other institutional missions are targeted. Key design features of the SGEO platform are high flexibility and modularity in order to accommodate a very wide range of future missions, a short development time below two years and the objective to build the system based on ITAR free subsystems and components. The system will provide a long lifetime of up to 15 years in orbit operations with high reliability. SGEO is the first European satellite to perform all orbit control tasks solely by electrical propulsion (EP). This design provides high mass efficiency and the capability for direct injection into geostationary orbit without chemical propulsion (CP). Optionally, an Apogee Engine Module based on CP will provide the perigee raising manoeuvres in case of a launch into geostationary transfer orbit (GTO). This approach allows an ideal choice out of a wide range of launcher candidates in dependence of the required payload capacity. SGEO will offer to the market a versatile and high performance satellite system with low investment risk for the customer and a short development time. This paper provides an overview of the SGEO system key features and the current status of the SGEO programme.

Interconnection of Broadband Islands via Satellite-Experiments on the Race II Catalyst Project

National Research Council Canada - National Science Library

Sun, Z

1996-01-01

.... The purpose of the project was to develop an ATM satellite link for the future B-ISDN services, particularly for the interconnections of the ATM testbeds which are in the form of broadband islands...

Analysis on Sealing Reliability of Bolted Joint Ball Head Component of Satellite Propulsion System

Science.gov (United States)

Guo, Tao; Fan, Yougao; Gao, Feng; Gu, Shixin; Wang, Wei

2018-01-01

Propulsion system is one of the important subsystems of satellite, and its performance directly affects the service life, attitude control and reliability of the satellite. The Paper analyzes the sealing principle of bolted joint ball head component of satellite propulsion system and discuss from the compatibility of hydrazine anhydrous and bolted joint ball head component, influence of ground environment on the sealing performance of bolted joint ball heads, and material failure caused by environment, showing that the sealing reliability of bolted joint ball head component is good and the influence of above three aspects on sealing of bolted joint ball head component can be ignored.

Above the cloud computing: applying cloud computing principles to create an orbital services model

Science.gov (United States)

Straub, Jeremy; Mohammad, Atif; Berk, Josh; Nervold, Anders K.

2013-05-01

Large satellites and exquisite planetary missions are generally self-contained. They have, onboard, all of the computational, communications and other capabilities required to perform their designated functions. Because of this, the satellite or spacecraft carries hardware that may be utilized only a fraction of the time; however, the full cost of development and launch are still bone by the program. Small satellites do not have this luxury. Due to mass and volume constraints, they cannot afford to carry numerous pieces of barely utilized equipment or large antennas. This paper proposes a cloud-computing model for exposing satellite services in an orbital environment. Under this approach, each satellite with available capabilities broadcasts a service description for each service that it can provide (e.g., general computing capacity, DSP capabilities, specialized sensing capabilities, transmission capabilities, etc.) and its orbital elements. Consumer spacecraft retain a cache of service providers and select one utilizing decision making heuristics (e.g., suitability of performance, opportunity to transmit instructions and receive results - based on the orbits of the two craft). The two craft negotiate service provisioning (e.g., when the service can be available and for how long) based on the operating rules prioritizing use of (and allowing access to) the service on the service provider craft, based on the credentials of the consumer. Service description, negotiation and sample service performance protocols are presented. The required components of each consumer or provider spacecraft are reviewed. These include fully autonomous control capabilities (for provider craft), a lightweight orbit determination routine (to determine when consumer and provider craft can see each other and, possibly, pointing requirements for craft with directional antennas) and an authentication and resource utilization priority-based access decision making subsystem (for provider craft

The Design and Implementation of the Petite Amateur Naval Satellite (PANSAT) User Service Software

National Research Council Canada - National Science Library

Hunter, George

1998-01-01

... or eventually replace the existing military satellite communications architecture. While more than eight years of work has gone into the project, most of the nearly sixty theses thus far have dealt with hardware development...

Analysis of Patient Visits and Collections After Opening a Satellite Pediatric Emergency Department.

Science.gov (United States)

Nichols, Katherine M; Caperell, Kerry; Cross, Keith; Duncan, Scott; Foster, Ben; Liu, Gil; Pritchard, Hank; Southard, Gary; Shinabery, Ben; Sutton, Brad; Kim, In K

2018-04-01

Satellite pediatric emergency departments (PEDs) have emerged as a strategy to increase patient capacity. We sought to determine the impact on patient visits, physician fee collections, and value of emergency department (ED) time at the primary PED after opening a nearby satellite PED. We also illustrate the spatial distribution of patient demographics and overlapping catchment areas for the primary and satellite PEDs using geographical information system. A structured, financial retrospective review was conducted. Aggregate patient demographic data and billing data were collected regarding physician fee charges, collections, and patient visits for both PEDs. All ED visits from January 2009 to December 2013 were analyzed. Geographical information system mapping using ArcGIS mapped ED patient visits. Patient visits at the primary PED were 53,050 in 2009 before the satellite PED opened. The primary PED visits increased after opening the satellite PED to 55,932 in 2013. The satellite PED visits increased to 21,590 in 2013. Collections per visit at the primary PED decreased from $105.13 per visit in 2011 to $86.91 per visit in 2013. Total collections at the satellite PED decreased per visit from $155.41 per visit in 2011 to $128.53 per visit in 2013. After opening a nearby satellite PED, patient visits at the primary PED did not substantially decrease, suggesting that there was a previously unrecognized demand for PED services. The collections per ED visit were greater at the satellite ED, likely due to a higher collection rate.

Emerging Technologies: Small Satellite and Associated TPED

Science.gov (United States)

Zitz, R.

2014-09-01

The 2010 National Space Policy directs the U.S. space community, comprised of the Department of Defense, Intelligence Community, Military Services and NASA to examine our nation's ability to conduct space-based ISR and communications even during a period of peer state and near peer state attacks intended to deny us our advantages we accrue from our use of space systems. DOD and the ICs past experience is largely one of building small numbers of extraordinarily capable and expensive (exquisite) satellites for communications and ISR. As potential adversaries continue to develop cyber-attack capabilities and have demonstrated an ability to kinetically attack spacecraft, the vulnerability of our architecture is now a serious concern. In addition, the sluggish U.S. economy, the draw down and pull back from a decade of combat operations, and other factors have combined to force a significant reduction in DOD and IC spending over the coming decade(s). Simultaneously, DOD and the IC have a growing awareness that the long lead times and long mission duration of the exquisite space assets can lead to fielding technologies that become obsolete and mission limiting. Some DOD and IC leaders are now examining alternative architectures to provide lower cost, flexible, more diverse and rapidly launchable space systems. Government leaders are considering commercially hosted payloads in geosynchronous orbits and smaller, lower cost, free flying government and commercial satellites in low earth orbits. Additional changes to the ground tasking, processing, exploitation and dissemination (TPED) systems would ensure small satellites have end-to-end mission capability and meet emerging needs such as ease of tasking, multi-INT processing, and more advanced distribution mechanisms (e.g., to users on the move). Today, a majority of agency leaders and their subordinate program managers remain convinced that only large, expensive systems can truly answer requirements and provide reliable

Satellite Media Broadcasting with Adaptive Coding and Modulation

Directory of Open Access Journals (Sweden)

Georgios Gardikis

2009-01-01

Full Text Available Adaptive Coding and Modulation (ACM is a feature incorporated into the DVB-S2 satellite specification, allowing real-time adaptation of transmission parameters according to the link conditions. Although ACM was originally designed for optimizing unicast services, this article discusses the expansion of its usage to broadcasting streams as well. For this purpose, a general cross-layer adaptation approach is proposed, along with its realization into a fully functional experimental network, and test results are presented. Finally, two case studies are analysed, assessing the gain derived by ACM in a real large-scale deployment, involving HD services provision to two different geographical areas.

When Enrollments Bulge but Budgets Don't, Consider "Satellite Learning Centers."

Science.gov (United States)

Reecer, Marcia

1988-01-01

Describes Dade County (Florida) schools' answer to crowded classrooms and burgeoning primary enrollments: satellite learning centers built and maintained by local companies as employee childcare benefits. Each center is attached to a nearby "host" school that disburses funds, keeps student records, and supplies support services. (MLH)

Global Broadcast Service Reach Back Via Satellite Tactical Digital Link J (S-TADIL J)

National Research Council Canada - National Science Library

Fenton, Sandra

1999-01-01

...) to deployed forces via UHF Follow On (UFO) satellites during GBS Phase Two. The concept of Smart Push provides for most of the users' needs but cannot anticipate every need or emerging needs of the user...

The beginning of a new era - OTC's satellite business services

Science.gov (United States)

Bachmann, Erik

OTC has developed a new range of digital services which will provide business organizations in Australia with high quality private international telecommunications. This range will be known as Satnet and the paper deals with Satnet 2 which is the service offerings using medium-size earth stations (nominally 5- and 7-meter antenna apertures), installed at customers' premises. These services will rely on the Intelsat 6/4 GHz space segment. Operation will be totally digital and will be integrated with no distinction between individual applications such as voice, data, video, etc. Carrier capacities between 64 kb/s and 8.448 Mb/s can be provided and ISDN performance requirements can be supported. The paper describes key service features, systems design and transmission analysis. Consideration is also given to operation, installation and frequency coordination aspects.

Precise Point Positioning with the BeiDou Navigation Satellite System

Directory of Open Access Journals (Sweden)

Min Li

2014-01-01

Full Text Available By the end of 2012, China had launched 16 BeiDou-2 navigation satellites that include six GEOs, five IGSOs and five MEOs. This has provided initial navigation and precise pointing services ability in the Asia-Pacific regions. In order to assess the navigation and positioning performance of the BeiDou-2 system, Wuhan University has built up a network of BeiDou Experimental Tracking Stations (BETS around the World. The Position and Navigation Data Analyst (PANDA software was modified to determine the orbits of BeiDou satellites and provide precise orbit and satellite clock bias products from the BeiDou satellite system for user applications. This article uses the BeiDou/GPS observations of the BeiDou Experimental Tracking Stations to realize the BeiDou and BeiDou/GPS static and kinematic precise point positioning (PPP. The result indicates that the precision of BeiDou static and kinematic PPP reaches centimeter level. The precision of BeiDou/GPS kinematic PPP solutions is improved significantly compared to that of BeiDou-only or GPS-only kinematic PPP solutions. The PPP convergence time also decreases with the use of combined BeiDou/GPS systems.

Precise point positioning with the BeiDou navigation satellite system.

Science.gov (United States)

Li, Min; Qu, Lizhong; Zhao, Qile; Guo, Jing; Su, Xing; Li, Xiaotao

2014-01-08

By the end of 2012, China had launched 16 BeiDou-2 navigation satellites that include six GEOs, five IGSOs and five MEOs. This has provided initial navigation and precise pointing services ability in the Asia-Pacific regions. In order to assess the navigation and positioning performance of the BeiDou-2 system, Wuhan University has built up a network of BeiDou Experimental Tracking Stations (BETS) around the World. The Position and Navigation Data Analyst (PANDA) software was modified to determine the orbits of BeiDou satellites and provide precise orbit and satellite clock bias products from the BeiDou satellite system for user applications. This article uses the BeiDou/GPS observations of the BeiDou Experimental Tracking Stations to realize the BeiDou and BeiDou/GPS static and kinematic precise point positioning (PPP). The result indicates that the precision of BeiDou static and kinematic PPP reaches centimeter level. The precision of BeiDou/GPS kinematic PPP solutions is improved significantly compared to that of BeiDou-only or GPS-only kinematic PPP solutions. The PPP convergence time also decreases with the use of combined BeiDou/GPS systems.

Satellite myths

Science.gov (United States)

Easton, Roger L.; Hall, David

2008-01-01

Richard Corfield's article “Sputnik's legacy” (October 2007 pp23-27) states that the satellite on board the US Vanguard rocket, which exploded during launch on 6 December 1957 two months after Sputnik's successful take-off, was “a hastily put together contraption of wires and circuitry designed only to send a radio signal back to Earth”. In fact, the Vanguard satellite was developed over a period of several years and put together carefully using the best techniques and equipment available at the time - such as transistors from Bell Laboratories/Western Electric. The satellite contained not one but two transmitters, in which the crystal-controlled oscillators had been designed to measure both the temperature of the satellite shell and of the internal package.

A Space-Based Learning Service for Schools Worldwide

Science.gov (United States)

White, Norman A.; Gibson, Alan

2002-01-01

This paper outlines a scheme for international collaboration to enrich the use of space in school education, to improve students' learning about science and related subjects and to enhance the continuity of science-related studies after the age of 16. Guidelines are presented for the design of an on-line learning service to provide schools worldwide with:- interactive curriculum-related learning resources for teaching about space and through - access to a purpose-designed education satellite or satellites; - opportunities for hands-on work by students in out-of-school hours; - news about space developments to attract, widen and deepen initial interest among teachers - support services to enable teachers to make effective use of the learning service. The Learning Service is the product of almost twenty years of experience by a significant number of UK schools in experimenting with, and in using, satellites and space to aid learning; and over four years of study and development by the SpaceLink Learning Foundation - a private-sector, not- for-profit UK registered charity, which is dedicated to help in increasing both the supply of scientists and engineers and the public understanding of science. This initiative provides scope for, and could benefit from, the involvement of relevant/interested organisations drawn from different countries. The Foundation would be ready, from its UK base, to be among such a group of initiating organisations.

The open prototype for educational NanoSats: Fixing the other side of the small satellite cost equation

Science.gov (United States)

Berk, Josh; Straub, Jeremy; Whalen, David

Government supported nano-satellite launch programs and emerging commercial small satellite launch services are reducing the cost of access to space for educational and other CubeSat projects. The cost and complexity of designing and building these satellites remains a vexing complication for many would be CubeSat aspirants. The Open Prototype for Educational NanoSats (OPEN), a proposed nano-satellite development platform, is described in this paper. OPEN endeavors to reduce the costs and risks associated with educational, government and commercial nano-satellite development. OPEN provides free and publicly available plans for building, testing and operating a versatile, low-cost satellite, based on the standardized CubeSat form-factor. OPEN consists of public-domain educational reference plans, complete with engineering schematics, CAD files, construction and test instructions as well as ancillary reference materials relevant to satellite building and operation. By making the plan, to produce a small but capable spacecraft freely available, OPEN seeks to lower the barriers to access on the other side (non-launch costs) of the satellite cost equation.

Open Source GIS Connectors to NASA GES DISC Satellite Data

Science.gov (United States)

Kempler, Steve; Pham, Long; Yang, Wenli

2014-01-01

The NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) houses a suite of high spatiotemporal resolution GIS data including satellite-derived and modeled precipitation, air quality, and land surface parameter data. The data are valuable to various GIS research and applications at regional, continental, and global scales. On the other hand, many GIS users, especially those from the ArcGIS community, have difficulties in obtaining, importing, and using our data due to factors such as the variety of data products, the complexity of satellite remote sensing data, and the data encoding formats. We introduce a simple open source ArcGIS data connector that significantly simplifies the access and use of GES DISC data in ArcGIS.

Network flexibility of the IRIDIUM (R) Global Mobile Satellite System

Science.gov (United States)

Hutcheson, Jonathan; Laurin, Mala

1995-01-01

The IRIDIUM system is a global personal communications system supported by a constellation of 66 low earth orbit (LEO) satellites and a collection of earth-based 'gateway' switching installations. Like traditional wireless cellular systems, coverage is achieved by a grid of cells in which bandwidth is reused for spectral efficiency. Unlike any cellular system ever built, the moving cells can be shared by multiple switching facilities. Noteworthy features of the IRIDIUM system include inter-satellite links, a GSM-based telephony architecture, and a geographically controlled system access process. These features, working in concert, permit flexible and reliable administration of the worldwide service area by gateway operators. This paper will explore this unique concept.

Programming a real-time operating system for satellite control applications Satellite Control Applications

International Nuclear Information System (INIS)

Omer, M.; Anjum, O.; Suddle, M.R.

2004-01-01

With the realization of ideas like formation flights and multi-body space vehicles the demands on an attitude control system have become increasingly complex. Even in its most simplified form, the control system for a typical geostationary satellite has to run various supervisory functions along with determination and control algorithms side by side. Within each algorithm it has to employ multiple actuation and sensing mechanisms and service real time interrupts, for example, in the case of actuator saturation and sensor data fusion. This entails the idea of thread scheduling and program synchronization, tasks specifically meant for a real time OS. This paper explores the embedding of attitude determination and control loop within the framework of a real time operating system provided for TI's DSP C6xxx series. The paper details out the much functionality provided within the scaleable real time kernel and the analysis and configuration tools available, It goes on to describe a layered implementation stack associated with a typical control for Geo Stationary satellites. An application for control is then presented in which state of the art analysis tools are employed to view program threads, synchronization semaphores, hardware interrupts and data exchange pipes operating in real time. (author)

History of Satellite TV Broadcasting and Satellite Broadcasting Market in Turkey

Directory of Open Access Journals (Sweden)

Mihalis KUYUCU

2015-09-01

Full Text Available 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 quality and geographical coverage of the television media. A conceptual study was carried out in the first part of the study in connection with the history of satellite broadcasting in Turkey and across the world. In the research part of the study, an analysis was performed on 160 television channels that broadcast in Turkey via Turksat Satellite. Economic structure of the television channels broadcasting in Turkey via satellite was studied and an analysis was perfo rmed on the operational structure of the channels. As a result of the study, it was emphasized that the television channels broadcasting via satellite platform also use other platforms for the purpose of spreading their broadcasts and television channel ow ners make investments in different branches of the media, too. Capital owners invest in different business areas other than the media although television channels broadcasting via Turksat mostly focus on thematic broadcasting and make effort to generate ec onomic income from advertisements. Delays are encountered in the course of the convergence between the new media and television channels that broadcast only from the satellite platform and such television channels experience more economic problems than the other channels. New media and many TV broadcasting platforms emerged as a result of the developments in the communication technologies. In television broadcasting, satellite platform is not an effective platform on its own. Channels make effort to reach t o more people by using other platforms in addition to

Relative tracking control of constellation satellites considering inter-satellite link

Science.gov (United States)

Fakoor, M.; Amozegary, F.; Bakhtiari, M.; Daneshjou, K.

2017-11-01

In this article, two main issues related to the large-scale relative motion of satellites in the constellation are investigated to establish the Inter Satellite Link (ISL) which means the dynamic and control problems. In the section related to dynamic problems, a detailed and effective analytical solution is initially provided for the problem of satellite relative motion considering perturbations. The direct geometric method utilizing spherical coordinates is employed to achieve this solution. The evaluation of simulation shows that the solution obtained from the geometric method calculates the relative motion of the satellite with high accuracy. Thus, the proposed analytical solution will be applicable and effective. In the section related to control problems, the relative tracking control system between two satellites will be designed in order to establish a communication link between the satellites utilizing analytical solution for relative motion of satellites with respect to the reference trajectory. Sliding mode control approach is employed to develop the relative tracking control system for body to body and payload to payload tracking control. Efficiency of sliding mode control approach is compared with PID and LQR controllers. Two types of payload to payload tracking control considering with and without payload degree of freedom are designed and suitable one for practical ISL applications is introduced. Also, Fuzzy controller is utilized to eliminate the control input in the sliding mode controller.

Satellite Geomagnetism

DEFF Research Database (Denmark)

Olsen, Nils; Stolle, Claudia

2012-01-01

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

NASA/DARPA advanced communications technology satellite project for evaluation of telemedicine outreach using next-generation communications satellite technology: Mayo Foundation participation.

Science.gov (United States)

Gilbert, B K; Mitchell, M P; Bengali, A R; Khandheria, B K

1999-08-01

To describe the development of telemedicine capabilities-application of remote consultation and diagnostic techniques-and to evaluate the feasibility and practicality of such clinical outreach to rural and underserved communities with limited telecommunications infrastructures. In 1992, Mayo Foundation (Rochester, Minn, Jacksonville, Fla, and Scottsdale, Ariz), the National Aeronautics and Space Administration, and the Defense Advanced Research Projects Agency collaborated to create a complex network of fiberoptic landlines, video recording systems, satellite terminals, and specially developed data translators linking Mayo sites with other locations in the continental United States on an on-demand basis. The purpose was to transmit data via the asynchronous transfer mode (ATM) digital communications protocol over the Advanced Communications Technology Satellite. The links were intended to provide a conduit for transmission of data for patient-specific consultations between physicians, evaluation of medical imagery, and medical education for clinical staffs at remote sites. Low-data-rate (LDR) experiments went live late in 1993. Mayo Clinic Rochester successfully provided medical consultation and services to 2 small regional medical facilities. High-data-rate (HDR) experiments included studies of remote digital echocardiography, store-and-forward telemedicine, cardiac catheterization, and teleconsultation for congenital heart disease. These studies combined landline data transmission with use of the satellite. The complexity of the routing paths and network components, immaturity of available software, and inexperience with existing telecommunications caused significant study delays. These experiments demonstrated that next-generation satellite technology can provide batch and real-time imagery for telemedicine. The first-generation of the ATM and satellite network technology used in these experiments created several technical problems and inconveniences that should

Payload system tradeoffs for mobile communications satellites

Science.gov (United States)

Moody, H. J.

1990-01-01

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

Design mobile satellite system architecture as an integral part of the cellular access digital network

Science.gov (United States)

Chien, E. S. K.; Marinho, J. A.; Russell, J. E., Sr.

1988-01-01

The Cellular Access Digital Network (CADN) is the access vehicle through which cellular technology is brought into the mainstream of the evolving integrated telecommunications network. Beyond the integrated end-to-end digital access and per call network services provisioning of the Integrated Services Digital Network (ISDN), the CADN engenders the added capability of mobility freedom via wireless access. One key element of the CADN network architecture is the standard user to network interface that is independent of RF transmission technology. Since the Mobile Satellite System (MSS) is envisioned to not only complement but also enhance the capabilities of the terrestrial cellular telecommunications network, compatibility and interoperability between terrestrial cellular and mobile satellite systems are vitally important to provide an integrated moving telecommunications network of the future. From a network standpoint, there exist very strong commonalities between the terrestrial cellular system and the mobile satellite system. Therefore, the MSS architecture should be designed as an integral part of the CADN. This paper describes the concept of the CADN, the functional architecture of the MSS, and the user-network interface signaling protocols.

Potential Market for Satellite Technology in Meeting Telecommunication Needs of Developing Nations

Science.gov (United States)

1996-01-01

A recent study examined the potential for satellite technology to meet the telecommunication needs of developing nations. The growth of these nations depends on their attracting and holding the industrial investments of developed nations. This will not be likely with the antiquated telecommunications infrastructure typical of developing nations. On the contrary, it will require an infrastructure that is compatible with international standards. Most of the developing nations perceive this necessity and are pursuing the necessary upgrades. The rate of replacement, types of technology, services affected, and the terrestrial/satellite mix differ by each nation's priorities and gross national product (GNP).

Handbook of satellite applications

CERN Document Server

Madry, Scott; Camacho-Lara, Sergio

2017-01-01

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

Satellite image collection optimization

Science.gov (United States)

Martin, William

2002-09-01

Imaging satellite systems represent a high capital cost. Optimizing the collection of images is critical for both satisfying customer orders and building a sustainable satellite operations business. We describe the functions of an operational, multivariable, time dynamic optimization system that maximizes the daily collection of satellite images. A graphical user interface allows the operator to quickly see the results of what if adjustments to an image collection plan. Used for both long range planning and daily collection scheduling of Space Imaging's IKONOS satellite, the satellite control and tasking (SCT) software allows collection commands to be altered up to 10 min before upload to the satellite.

Satellite-based Tropical Cyclone Monitoring Capabilities

Science.gov (United States)

Hawkins, J.; Richardson, K.; Surratt, M.; Yang, S.; Lee, T. F.; Sampson, C. R.; Solbrig, J.; Kuciauskas, A. P.; Miller, S. D.; Kent, J.

2012-12-01

Satellite remote sensing capabilities to monitor tropical cyclone (TC) location, structure, and intensity have evolved by utilizing a combination of operational and research and development (R&D) sensors. The microwave imagers from the operational Defense Meteorological Satellite Program [Special Sensor Microwave/Imager (SSM/I) and the Special Sensor Microwave Imager Sounder (SSMIS)] form the "base" for structure observations due to their ability to view through upper-level clouds, modest size swaths and ability to capture most storm structure features. The NASA TRMM microwave imager and precipitation radar continue their 15+ yearlong missions in serving the TC warning and research communities. The cessation of NASA's QuikSCAT satellite after more than a decade of service is sorely missed, but India's OceanSat-2 scatterometer is now providing crucial ocean surface wind vectors in addition to the Navy's WindSat ocean surface wind vector retrievals. Another Advanced Scatterometer (ASCAT) onboard EUMETSAT's MetOp-2 satellite is slated for launch soon. Passive microwave imagery has received a much needed boost with the launch of the French/Indian Megha Tropiques imager in September 2011, basically greatly supplementing the very successful NASA TRMM pathfinder with a larger swath and more frequent temporal sampling. While initial data issues have delayed data utilization, current news indicates this data will be available in 2013. Future NASA Global Precipitation Mission (GPM) sensors starting in 2014 will provide enhanced capabilities. Also, the inclusion of the new microwave sounder data from the NPP ATMS (Oct 2011) will assist in mapping TC convective structures. The National Polar orbiting Partnership (NPP) program's VIIRS sensor includes a day night band (DNB) with the capability to view TC cloud structure at night when sufficient lunar illumination exits. Examples highlighting this new capability will be discussed in concert with additional data fusion efforts.

Trends in communications satellites

CERN Document Server

Curtin, Denis J

1979-01-01

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

Theory of satellite geodesy applications of satellites to geodesy

CERN Document Server

Kaula, William M

2000-01-01

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

International Laser Ranging Service (ILRS): Terms of Reference

Science.gov (United States)

Husson, Van; Noll, Carey

2000-01-01

The International Laser Ranging Service (ILRS) is an established Service within Section II , Advanced Space Technology, of the International Association of Geodesy (IAG). The primary objective of the ILRS is to provide a service to support, through Satellite and Lunar Laser Ranging data and related products, geodetic and geophysical research activities as well as International Earth Rotation Service (IERS) products important to the maintenance of an accurate International Terrestrial Reference Frame (ITRF). The service also develops the necessary standards/specifications and encourages international adherence to its conventions.

R and D limited partnerships (possible applications in advanced communications satellite technology experiment program)

Science.gov (United States)

1985-01-01

Typical R&D limited partnership arrangements, advantages and disadvantages of R&D limited partnership (RDLPs) and antitrust and tax implications are described. A number of typical forms of RDLPs are described that may be applicable for use in stimulating R&D and experimental programs using the advanced communications technology satellite. The ultimate goal is to increase the rate of market penetration of goods and/or services based upon advanced satellite communications technology. The conditions necessary for these RDLP forms to be advantageous are outlined.

Advances in Robotic Servicing Technology Development

Science.gov (United States)

Gefke, Gardell G.; Janas, Alex; Pellegrino, Joseph; Sammons, Matthew; Reed, Benjamin

2015-01-01

NASA's Satellite Servicing Capabilities Office (SSCO) has matured robotic and automation technologies applicable to in-space robotic servicing and robotic exploration over the last six years. This paper presents the progress of technology development activities at the Goddard Space Flight Center Servicing Technology Center and on the ISS, with an emphasis on those occurring in the past year. Highlighted advancements are design reference mission analysis for servicing in low Earth orbit (LEO) and asteroid redirection; delivery of the engineering development unit of the NASA Servicing Arm; an update on International Space Station Robotic Refueling Mission; and status of a comprehensive ground-based space robot technology demonstration expanding in-space robotic servicing capabilities beginning fall 2015.

Streamlining On-Demand Access to Joint Polar Satellite System (JPSS) Data Products for Weather Forecasting

Science.gov (United States)

Evans, J. D.; Tislin, D.

2017-12-01

Observations from the Joint Polar Satellite System (JPSS) support National Weather Service (NWS) forecasters, whose Advanced Weather Interactive Processing System (AWIPS) Data Delivery (DD) will access JPSS data products on demand from the National Environmental Satellite, Data, and Information Service (NESDIS) Product Distribution and Access (PDA) service. Based on the Open Geospatial Consortium (OGC) Web Coverage Service, this on-demand service promises broad interoperability and frugal use of data networks by serving only the data that a user needs. But the volume, velocity, and variety of JPSS data products impose several challenges to such a service. It must be efficient to handle large volumes of complex, frequently updated data, and to fulfill many concurrent requests. It must offer flexible data handling and delivery, to work with a diverse and changing collection of data, and to tailor its outputs into products that users need, with minimal coordination between provider and user communities. It must support 24x7 operation, with no pauses in incoming data or user demand; and it must scale to rapid changes in data volume, variety, and demand as new satellites launch, more products come online, and users rely increasingly on the service. We are addressing these challenges in order to build an efficient and effective on-demand JPSS data service. For example, on-demand subsetting by many users at once may overload a server's processing capacity or its disk bandwidth - unless alleviated by spatial indexing, geolocation transforms, or pre-tiling and caching. Filtering by variable (/ band / layer) may also alleviate network loads, and provide fine-grained variable selection; to that end we are investigating how best to provide random access into the variety of spatiotemporal JPSS data products. Finally, producing tailored products (derivatives, aggregations) can boost flexibility for end users; but some tailoring operations may impose significant server loads

Satellite Communications

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Satellite Communications. Arthur C Clarke wrote a seminal paper in 1945 in wireless world. Use three satellites in geo-synchronous orbit to enable intercontinental communications. System could be realised in '50 to 100 years'

NASA to launch second business communications satellite

Science.gov (United States)

1981-01-01

The two stage Delta 3910 launch vehicle was chosen to place the second small business satellite (SBS-B) into a transfer orbit with an apogee of 36,619 kilometers and a perigee of 167 km, at an inclination of 27.7 degrees to Earth's equator. The firing and separation sequence and the inertial guidance system are described as well as the payload assist module. Facilities and services for tracking and control by NASA, COMSAT, Intelsat, and SBS are outlined and prelaunch operations are summarized.

Crop classification based on multi-temporal satellite remote sensing data for agro-advisory services

Science.gov (United States)

Karale, Yogita; Mohite, Jayant; Jagyasi, Bhushan

2014-11-01

In this paper, we envision the use of satellite images coupled with GIS to obtain location specific crop type information in order to disseminate crop specific advises to the farmers. In our ongoing mKRISHI R project, the accurate information about the field level crop type and acreage will help in the agro-advisory services and supply chain planning and management. The key contribution of this paper is the field level crop classification using multi temporal images of Landsat-8 acquired during November 2013 to April 2014. The study area chosen is Vani, Maharashtra, India, from where the field level ground truth information for various crops such as grape, wheat, onion, soybean, tomato, along with fodder and fallow fields has been collected using the mobile application. The ground truth information includes crop type, crop stage and GPS location for 104 farms in the study area with approximate area of 42 hectares. The seven multi-temporal images of the Landsat-8 were used to compute the vegetation indices namely: Normalized Difference Vegetation Index (NDVI), Simple Ratio (SR) and Difference Vegetation Index (DVI) for the study area. The vegetation indices values of the pixels within a field were then averaged to obtain the field level vegetation indices. For each crop, binary classification has been carried out using the feed forward neural network operating on the field level vegetation indices. The classification accuracy for the individual crop was in the range of 74.5% to 97.5% and the overall classification accuracy was found to be 88.49%.

Geostationary Satellite (GOES) Images

Data.gov (United States)

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

Near-toll quality digital speech transmission in the mobile satellite service

Science.gov (United States)

Townes, S. A.; Divsalar, D.

1986-01-01

This paper discusses system considerations for near-toll quality digital speech transmission in a 5 kHz mobile satellite system channel. Tradeoffs are shown for power performance versus delay for a 4800 bps speech compression system in conjunction with a 16 state rate 2/3 trellis coded 8PSK modulation system. The suggested system has an additional 150 ms of delay beyond the propagation delay and requires an E(b)/N(0) of about 7 dB for a Ricean channel assumption with line-of-sight to diffuse component ratio of 10 assuming ideal synchronization. An additional loss of 2 to 3 dB is expected for synchronization in fading environment.

Multi-GNSS orbit determination using satellite laser ranging

Science.gov (United States)

Bury, Grzegorz; Sośnica, Krzysztof; Zajdel, Radosław

2018-04-01

Galileo, BeiDou, QZSS, and NavIC are emerging global navigation satellite systems (GNSSs) and regional navigation satellite systems all of which are equipped with laser retroreflector arrays for range measurements. This paper summarizes the GNSS-intensive tracking campaigns conducted by the International Laser Ranging Service and provides results from multi-GNSS orbit determination using solely SLR observations. We consider the whole constellation of GLONASS, all active Galileo, four BeiDou satellites: 1 MEO, 3 IGSO, and one QZSS. We analyze the influence of the number of SLR observations on the quality of the 3-day multi-GNSS orbit solution. About 60 SLR observations are needed for obtaining MEO orbits of sufficient quality with the root mean square (RMS) of 3 cm for the radial component when compared to microwave-based orbits. From the analysis of a minimum number of tracking stations, when considering the 3-day arcs, 5 SLR stations do not provide a sufficient geometry of observations. The solution obtained using ten stations is characterized with RMS of 4, 9, and 18 cm in the radial, along-track, and cross-track direction, respectively, for MEO satellites. We also investigate the impact of the length of orbital arc on the quality of SLR-derived orbits. Hence, 5- and 7-day arcs constitute the best solution, whereas 3-day arcs are of inferior quality due to an insufficient number of SLR observations and 9-day arcs deteriorate the along-track component. The median RMS from the comparison between 7-day orbital arcs determined using SLR data with microwave-based orbits assumes values in the range of 3-4, 11-16, and 15-27 cm in radial, along-track, and cross-track, respectively, for MEO satellites. BeiDou IGSO and QZSS are characterized by RMS values higher by a factor of 8 and 24, respectively, than MEO orbits.

Causal relationships between solar proton events and single event upsets for communication satellites

Science.gov (United States)

Lohmeyer, W. Q.; Cahoy, K.; Liu, Shiyang

In this work, we analyze a historical archive of single event upsets (SEUs) maintained by Inmarsat, one of the world's leading providers of global mobile satellite communications services. Inmarsat has operated its geostationary communication satellites and collected extensive satellite anomaly and telemetry data since 1990. Over the course of the past twenty years, the satellites have experienced more than 226 single event upsets (SEUs), a catch-all term for anomalies that occur in a satellite's electronics such as bit-flips, trips in power supplies, and memory changes in attitude control systems. While SEUs are seemingly random and difficult to predict, we correlate their occurrences to space weather phenomena, and specifically show correlations between SEUs and solar proton events (SPEs). SPEs are highly energetic protons that originate from solar coronal mass ejections (CMEs). It is thought that when these particles impact geostationary (GEO) satellites they can cause SEUs as well as solar array degradation. We calculate the associated statistical correlations that each SEU occurs within one day, one week, two weeks, and one month of 10 MeV SPEs between 10 - 10,000 particle flux units (pfu). However, we find that SPEs are most prevalent at solar maximum and that the SEUs on Inmarsat's satellites occur out of phase with the solar maximum. Ultimately, this suggests that SPEs are not the primary cause of the Inmarsat SEUs. A better understanding of the causal relationship between SPEs and SEUs will help the satellite communications industry develop component and operational space weather mitigation techniques as well as help the space weather community to refine radiation models.

Theory of geostationary satellites

CERN Document Server

Zee, Chong-Hung

1989-01-01

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

The Technological Growth in eHealth Services

Directory of Open Access Journals (Sweden)

Shilpa Srivastava

2015-01-01

Full Text Available The infusion of information communication technology (ICT into health services is emerging as an active area of research. It has several advantages but perhaps the most important one is providing medical benefits to one and all irrespective of geographic boundaries in a cost effective manner, providing global expertise and holistic services, in a time bound manner. This paper provides a systematic review of technological growth in eHealth services. The present study reviews and analyzes the role of four important technologies, namely, satellite, internet, mobile, and cloud for providing health services.

The Technological Growth in eHealth Services

Science.gov (United States)

Srivastava, Shilpa; Pant, Millie; Abraham, Ajith; Agrawal, Namrata

2015-01-01

The infusion of information communication technology (ICT) into health services is emerging as an active area of research. It has several advantages but perhaps the most important one is providing medical benefits to one and all irrespective of geographic boundaries in a cost effective manner, providing global expertise and holistic services, in a time bound manner. This paper provides a systematic review of technological growth in eHealth services. The present study reviews and analyzes the role of four important technologies, namely, satellite, internet, mobile, and cloud for providing health services. PMID:26146515

The Technological Growth in eHealth Services.

Science.gov (United States)

Srivastava, Shilpa; Pant, Millie; Abraham, Ajith; Agrawal, Namrata

2015-01-01

The infusion of information communication technology (ICT) into health services is emerging as an active area of research. It has several advantages but perhaps the most important one is providing medical benefits to one and all irrespective of geographic boundaries in a cost effective manner, providing global expertise and holistic services, in a time bound manner. This paper provides a systematic review of technological growth in eHealth services. The present study reviews and analyzes the role of four important technologies, namely, satellite, internet, mobile, and cloud for providing health services.

Space Solar Power Satellite Systems, Modern Small Satellites, and Space Rectenna

Science.gov (United States)

Bergsrud, Corey Alexis Marvin

Space solar power satellite (SSPS) systems is the concept of placing large satellite into geostationary Earth orbit (GEO) to harvest and convert massive amounts of solar energy into microwave energy, and to transmit the microwaves to a rectifying antenna (rectenna) array on Earth. The rectenna array captures and converts the microwave power into usable power that is injected into the terrestrial electric grid for use. This work approached the microwave power beam as an additional source of power (with solar) for lower orbiting satellites. Assuming the concept of retrodirectivity, a GEO-SSPS antenna array system tracks and delivers microwave power to lower orbiting satellites. The lower orbiting satellites are equipped with a stacked photovoltaic (PV)/rectenna array hybrid power generation unit (HPGU) in order to harvest solar and/or microwave energy for on-board use during orbit. The area, and mass of the PV array part of the HPGU was reduced at about 32% beginning-of-life power in order to achieve the spacecraft power requirements. The HPGU proved to offer a mass decrease in the PGU, and an increase in mission life due to longer living component life of the rectenna array. Moreover, greater mission flexibility is achieved through a track and power delivery concept. To validate the potential advantages offered by a HPGU, a mission concept was presented that utilizes modern small satellites as technology demonstrators. During launch, a smaller power receiving "daughter" satellite sits inside a larger power transmitting "mother" satellite. Once separated from the launch vehicle the daughter satellite is ejected away from the mother satellite, and each satellite deploys its respective power transmitting or power receiving hardware's for experimentation. The concept of close proximity mission operations between the satellites is considered. To validate the technology of the space rectenna array part of the HPGU, six milestones were completed in the design. The first

Disaster warning system: Satellite feasibility and comparison with terrestrial systems. Volume 1: Executive summary

Science.gov (United States)

Spoor, J. H.; Hodge, W. H.; Fluk, M. J.; Bamford, T. F.

1974-01-01

The Disaster Warning System (DWS) is a conceptual system which will provide the National Weather Service (NWS) with communication services in the 1980s to help minimize losses caused by natural disasters. The object of this study is a comparative analysis between a terrestrial DWS and a satellite DWS. Baseline systems satisfying the NOAA requirements were synthesized in sufficient detail so that a comparison could be made in terms of performance and cost. The cost of both baseline systems is dominated by the disaster warning and spotter reporting functions. An effort was undertaken to reduce system cost through lower-capacity alternative systems generated by modifying the baseline systems. By reducing the number of required channels and modifying the spotter reporting techniques, alternative satellite systems were synthesized. A terrestrial alternative with the coverage reduced to an estimated 95 percent of the population was considered.

SatelliteDL: a Toolkit for Analysis of Heterogeneous Satellite Datasets

Science.gov (United States)

Galloy, M. D.; Fillmore, D.

2014-12-01

SatelliteDL is an IDL toolkit for the analysis of satellite Earth observations from a diverse set of platforms and sensors. The core function of the toolkit is the spatial and temporal alignment of satellite swath and geostationary data. The design features an abstraction layer that allows for easy inclusion of new datasets in a modular way. Our overarching objective is to create utilities that automate the mundane aspects of satellite data analysis, are extensible and maintainable, and do not place limitations on the analysis itself. IDL has a powerful suite of statistical and visualization tools that can be used in conjunction with SatelliteDL. Toward this end we have constructed SatelliteDL to include (1) HTML and LaTeX API document generation,(2) a unit test framework,(3) automatic message and error logs,(4) HTML and LaTeX plot and table generation, and(5) several real world examples with bundled datasets available for download. For ease of use, datasets, variables and optional workflows may be specified in a flexible format configuration file. Configuration statements may specify, for example, a region and date range, and the creation of images, plots and statistical summary tables for a long list of variables. SatelliteDL enforces data provenance; all data should be traceable and reproducible. The output NetCDF file metadata holds a complete history of the original datasets and their transformations, and a method exists to reconstruct a configuration file from this information. Release 0.1.0 distributes with ingest methods for GOES, MODIS, VIIRS and CERES radiance data (L1) as well as select 2D atmosphere products (L2) such as aerosol and cloud (MODIS and VIIRS) and radiant flux (CERES). Future releases will provide ingest methods for ocean and land surface products, gridded and time averaged datasets (L3 Daily, Monthly and Yearly), and support for 3D products such as temperature and water vapor profiles. Emphasis will be on NPP Sensor, Environmental and

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

Science.gov (United States)

2013-03-08

... Consumer and Governmental Affairs Bureau, Reference Information Center shall send a copy of this Report and... ground, ESAAs shall not be authorized for transmission at angles less than 5[deg] measured from the plane..., in the plane of the geostationary satellite orbit (GSO) as it appears at the particular earth station...

Utilization of photovoltaic for broadband satellite communications in rural area of Thailand

Science.gov (United States)

Jinayim, Theerawut; Mungkung, Narong; Kasayapanand, Nat

2013-06-01

Electricity, Information and Communication Technologies (ICTs) are very important not only in urban areas but also in rural areas. To provide ICTs service in rural areas, sources of electricity and communication infrastructures must be implemented. Electricity is a major condition due to the fact that all electronic devices needed it in order to power on, so that it is impossible to operate any forms of ICTs in areas where the main national grid line is unavailable. Almost rural areas of Thailand where the main national grid line is unavailable have very good sunlight intensity. Photovoltaic is the most effective renewable energy technologies in those areas for meeting electricity needed in areas that are not connected to the main national grid line. In this paper, the efficiency utilization of photovoltaic as source of electricity for broadband satellite communication systems as well as social and economic impact and quality of life of people in rural areas of Thailand are presented. The results show that most rural communities would be able to universally access to the basic telecommunications services such as internet access and public telephone via satellite communication systems. However, in some field case study, broadband internet access via satellite communication may be unnecessary for some rural communities and the most exactly rural communities needed are electricity for household usage and battery charger.

Broadband Internet Based Service to Passengers and Crew On-board Aircraft

Science.gov (United States)

Azzarelli, Tony

2003-07-01

The Connexion by BoeingSM (CbB) global network will provide broadband information services to aircraft passengers and crews. Through this Ku-band (14 GHz (uplink) and 11/12 GHz (downlink)) satellite-based system, aircraft passengers and crew will no longer be limited to pre-packaged services, but instead will be able to access the full range of broadband services from their seats using their laptop, PDA or the on-board IFE console.The kind of services offered to passengers are based on the internet/intranet access via their own laptops and PDA (using Ethernet wired cable, or wireless 802.11b access), while those offered to the crew can range between various crew application (such as weather updates and travel information) and aircraft health monitoring.The CbB system is divided into four basic layers of infrastructure:(1) an airborne segment, i.e. the Aircraft Earth Station (AES) consisting of proprietary high gain antenna, transceivers and other on-board subsystems providing a nominal return link data rate of 1 Mbps and a forward link data rates up to 20 Mbps;(2) a space segment consisting of leased satellite transponders on existing in-orbit Geostationary satellites;(3) a ground segment consisting of one or more leased satellite land earth stations (LESs) and redundant interconnection facilities; and;(4) a network operations centre (NOC) segment.During 2003, trials with Lufthansa (DLH) and British Airways (BA) have proved very successful. This has resulted in the recent signing of an agreement with Lufthansa which calls for the Connexion by BoeingSM service to be installed on Lufthansa's fleet of approximately 80 long-haul aircraft, including Boeing 747-400 and Airbus A330 and A340 aircraft, beginning in early 2004. BA is expected to follow soon. In addition to the successful recent service demonstrations, both Japan Airlines (JAL) and Scandinavian Airlines System (SAS) have announced their intent to install the revolutionary service on their long-range aircraft.

On the capabilities and limitations of high altitude pseudo-satellites

Science.gov (United States)

Gonzalo, Jesús; López, Deibi; Domínguez, Diego; García, Adrián; Escapa, Alberto

2018-04-01

The idea of self-sustaining air vehicles that excited engineers in the seventies has nowadays become a reality as proved by several initiatives worldwide. High altitude platforms, or Pseudo-satellites (HAPS), are unmanned vehicles that take advantage of weak stratospheric winds and solar energy to operate without interfering with current commercial aviation and with enough endurance to provide long-term services as satellites do. Target applications are communications, Earth observation, positioning and science among others. This paper reviews the major characteristics of stratospheric flight, where airplanes and airships will compete for best performance. The careful analysis of involved technologies and their trends allow budget models to shed light on the capabilities and limitations of each solution. Aerodynamics and aerostatics, structures and materials, propulsion, energy management, thermal control, flight management and ground infrastructures are the critical elements revisited to assess current status and expected short-term evolutions. Stratospheric airplanes require very light wing loading, which has been demonstrated to be feasible but currently limits their payload mass to few tenths of kilograms. On the other hand, airships need to be large and operationally complex but their potential to hover carrying hundreds of kilograms with reasonable power supply make them true pseudo-satellites with enormous commercial interest. This paper provides useful information on the relative importance of the technology evolutions, as well as on the selection of the proper platform for each application or set of payload requirements. The authors envisage prompt availability of both types of HAPS, aerodynamic and aerostatic, providing unprecedented services.

Mobile satellite business networks: A part of the European mobile system

Science.gov (United States)

deMateo, M. L.; Jongejans, A.; Loisy, C.; VanHimbeeck, C.; Marchal, J. P.; Borella, A.; Sartori, M.

1995-01-01

The European Space Agency (ESA) is presently procuring an L-band payload EMS, to be embarked on the ITALSAT-2 satellite due for launch in early 1996, in order to promote a regional European mobile system. One of the Land Mobile Communication systems supported by EMS is the MSBN (Mobile Satellite Business Network) voice and data system which will offer the services of a business network on a seamless European coverage. This paper will first recall the characteristics of the MSBN system, which is based on quasi-synchronized CDMA (Code Division Multiple Access) techniques in both directions, and then describe the CDMA receivers implementation. Main validation test results will also be reported confirming predicted performances.

Izviđanje satelitskih komunikacija u funkciji savremenih operacija / Reconnaissance of satellite communications in contemporary operations

Directory of Open Access Journals (Sweden)

Slaviša Đukanović

2004-05-01

Full Text Available Raspoloživi vojni resursi u bilo kojoj kategoriji nisu kritični u mirnodopskom periodu, jer se dimenzionišu za ratno naprezanje određenog nivoa. Međutim, u uslovima izvođenja borbenih dejstava postoje ekstremi u zahtevima za angažovanjem, koje sistemi ne mogu da izdrže. Takav slučaj je kod satelitskih komunikacija. U radu su prezentovane taktičko-tehničke i dinamičke osobine komercijalnih (INMARSAT, INTELSAT, IRIDIJUM.. i vojnih (DSCS, FLEET-SATCOM, NATO, SKYNET.. satelitskih sistema, koje su bitne za uspešno vođenje elektronskog rata. Takođe, dat je pregled raspoloživih korisničkih servisa savremenih satelitskih sistema (Internet provajding video-konferencije, prenos multimedija uživo, fax, e-mail, voice. Nova generacija širokopojasnih satelita, koja se pušta u rad tokom ove godine omogućiće globalni roming navedenih servisa INMARSAT satelitskom sistemu koji se sve češće koristi u vojne svrhe. U perspektivi je da se usluge koje pružaju satelitski sistemi (komunikacioni, navigacioni, izviđački meteorološki.. stave na raspolaganje nižim taktičkim jedinicama vazduhoplovima, pa čak i svakom vojniku ponaosob. Poznavanje satelitskih sistema potencijalnog agresora pruža mogućnost da se odrede ranjive tačke samog sistema sa aspekta izviđanja i ometanja. / Available military resources in any category are not critical in peace since they are tailored for military use under extreme conditions. However, some systems such as satellite communications, cannot meet extreme requirements during combat actions. The paper presents tactical and technical specifications and dynamic characteristics of commercial (INMARSAT. INTELSAT, IRIDIJUM,.. and military (DSCS, FLEET-SATCOM, NATO, SKYNET,.. satellite systems which are important for electronic warfare. The paper also gives available user services of contemporary satellite systems (Internet providing, videoconferences, live multi-media, fax, e-mail, voice. A new generation of

Design of a High Resolution Open Access Global Snow Cover Web Map Service Using Ground and Satellite Observations

Science.gov (United States)

Kadlec, J.; Ames, D. P.

2014-12-01

The aim of the presented work is creating a freely accessible, dynamic and re-usable snow cover map of the world by combining snow extent and snow depth datasets from multiple sources. The examined data sources are: remote sensing datasets (MODIS, CryoLand), weather forecasting model outputs (OpenWeatherMap, forecast.io), ground observation networks (CUAHSI HIS, GSOD, GHCN, and selected national networks), and user-contributed snow reports on social networks (cross-country and backcountry skiing trip reports). For adding each type of dataset, an interface and an adapter is created. Each adapter supports queries by area, time range, or combination of area and time range. The combined dataset is published as an online snow cover mapping service. This web service lowers the learning curve that is required to view, access, and analyze snow depth maps and snow time-series. All data published by this service are licensed as open data; encouraging the re-use of the data in customized applications in climatology, hydrology, sports and other disciplines. The initial version of the interactive snow map is on the website snow.hydrodata.org. This website supports the view by time and view by site. In view by time, the spatial distribution of snow for a selected area and time period is shown. In view by site, the time-series charts of snow depth at a selected location is displayed. All snow extent and snow depth map layers and time series are accessible and discoverable through internationally approved protocols including WMS, WFS, WCS, WaterOneFlow and WaterML. Therefore they can also be easily added to GIS software or 3rd-party web map applications. The central hypothesis driving this research is that the integration of user contributed data and/or social-network derived snow data together with other open access data sources will result in more accurate and higher resolution - and hence more useful snow cover maps than satellite data or government agency produced data by

Linking satellite ICT application businesses with regional innovation centers and investors: The EC “INVESaT” project

Science.gov (United States)

Ghiron, Florence; Kreisel, Joerg

2009-09-01

In the sector of information and communication technologies (ICT), whether in the USA, Japan, or Europe, innovative services are already in use, based on large-scale space-based infrastructure investments. Such systems are e.g. earth observation, telecommunication, and navigation, timing and positioning satellites. In combination with the advent of powerful handheld terminals and the demand for ubiquitous services, it is expected that info-mobility applications will reveal new sources of business in the years ahead, using in particular the Earth observation and future GALILEO systems to position any feature or user anywhere in the world within a few meter accuracy. Hence, satellite-based capabilities provide new and unique opportunities for economic stimulation and development. Many incubators and innovation centers in Europe have already grasped this growth potential. Yet, for many European players business growth appears below expectations compared to developments in the USA following the launch of GPS (Global Positioning System). Europe still has to overcome intrinsic barriers to seize these new business opportunities faster and with more visible economic impact by leveraging on SMEs and regional innovation centers to expand the commercial utilization of satellite capabilities and mobilization of appropriate financial resources. The paper elaborates on the INVESat project (funded by the EuropeInnova—European Commission), which aims at bridging the gap between Innovative enterprises and financial In VEstors in the emerging markets of SaTellite applications. The critical success factors required to stimulate and support more efficiently investments in this bread of innovative services will also be highlighted.

Dialing long distance : communications to northern operations like the MGP require sophisticated satellite networks for voice, data

Energy Technology Data Exchange (ETDEWEB)

Cook, D.

2006-04-15

Telecommunications will play a major role in the construction of the Mackenzie Gas Project due to the remoteness of its location and the volume of communication data required to support the number of people involved and the amount of construction activity. While suppliers for communications tools have not yet been identified, initial telecommunications plans call for the installation of communication equipment at all camps, major facility sites and construction locations. Equipment will be housed in self-contained, climate-controlled buildings called telecommunication service modules (TSMs), which will be connected to each other as well as to existing public communications networks. The infrastructure will support telephone and fax systems; Internet and electronic mail services; multiple channel very high frequency radios; air-to-ground communication at airstrips and helipads; ship-to-shore at barge landings; closed circuit television; satellite community antenna television; CBC radio broadcast; public address systems; security systems; and supervisory control and data acquisition (SCADA) systems. An Internet Protocol (IP) network with a voice telephone system will be implemented along with a geostationary orbit satellite network. Satellite servers and real-time data services will be used. Car kits that allow call and battery-operated self-contained telemetry devices designed to communicate via a satellite system have been commissioned for the project that are capable of providing cost-efficient and reliable asset tracking and fleet management in remote regions and assisting in deployment requirements. It was concluded that many of today's mega-projects are the driving factors behind new telecommunications solutions in remote areas. 1 fig.

Satellites, tweets, forecasts: the future of flood disaster management?

Science.gov (United States)

Dottori, Francesco; Kalas, Milan; Lorini, Valerio; Wania, Annett; Pappenberger, Florian; Salamon, Peter; Ramos, Maria Helena; Cloke, Hannah; Castillo, Carlos

2017-04-01

Floods have devastating effects on lives and livelihoods around the world. Structural flood defence measures such as dikes and dams can help protect people. However, it is the emerging science and technologies for flood disaster management and preparedness, such as increasingly accurate flood forecasting systems, high-resolution satellite monitoring, rapid risk mapping, and the unique strength of social media information and crowdsourcing, that are most promising for reducing the impacts of flooding. Here, we describe an innovative framework which integrates in real-time two components of the Copernicus Emergency mapping services, namely the European Flood Awareness System and the satellite-based Rapid Mapping, with new procedures for rapid risk assessment and social media and news monitoring. The integrated framework enables improved flood impact forecast, thanks to the real-time integration of forecasting and monitoring components, and increases the timeliness and efficiency of satellite mapping, with the aim of capturing flood peaks and following the evolution of flooding processes. Thanks to the proposed framework, emergency responders will have access to a broad range of timely and accurate information for more effective and robust planning, decision-making, and resource allocation.

Leo Satellite Communication through a LEO Constellation using TCP/IP Over ATM

Science.gov (United States)

Foore, Lawrence R.; Konangi, Vijay K.; Wallett, Thomas M.

1999-01-01

The simulated performance characteristics for communication between a terrestrial client and a Low Earth Orbit (LEO) satellite server are presented. The client and server nodes consist of a Transmission Control Protocol /Internet Protocol (TCP/IP) over ATM configuration. The ATM cells from the client or the server are transmitted to a gateway, packaged with some header information and transferred to a commercial LEO satellite constellation. These cells are then routed through the constellation to a gateway on the globe that allows the client/server communication to take place. Unspecified Bit Rate (UBR) is specified as the quality of service (QoS). Various data rates are considered.

Satellite Communications

CERN Document Server

Pelton, Joseph N

2012-01-01

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

Ozone Satellite Data Synergy and Combination with Non-satellite Data in the AURORA project

Science.gov (United States)

Cortesi, U.; Tirelli, C.; Arola, A.; Dragani, R.; Keppens, A.; Loenen, E.; Masini, A.; Tsiakos, , C.; van der A, R.; Verberne, K.

2017-12-01

The geostationary satellite constellation composed of TEMPO (North America), SENTINEL-4 (Europe) and GEMS (Asia) missions is a major instance of space component in the fundamentally new paradigm aimed at integrating information on air quality from a wide variety of sources. Space-borne data on tropospheric composition from new generation satellites have a growing impact in this context because of their unprecedented quantity and quality, while merging with non-satellite measurements and other types of auxiliary data via state-of-the-art modelling capabilities remains essential to fit the purpose of highly accurate information made readily available at high temporal and spatial resolution, both in analysis and forecast mode. Proper and effective implementation of this paradigm poses severe challenges to science, technology and applications that must be addressed in a closely interconnected manner to pave the way to high quality products and innovative services. Novel ideas and tools built on these three pillars are currently under investigation in the AURORA (Advanced Ultraviolet Radiation and Ozone Retrieval for Applications) Horizon 2020 project of the European Commission. The primary goal of the project is the proof of concept of a synergistic approach to the exploitation of Sentinel-4 and -5 Ozone measurements in the UV, Visible and Thermal Infrared based on the combination of an innovative data fusion method and assimilation models. The scientific objective shares the same level of priority with the technological effort to realize a prototype data processor capable to manage the full data processing chain and with the development of two downstream applications for demonstration purposes. The presentation offers a first insight in mid-term results of the project, which is mostly based on the use of synthetic data from the atmospheric Sentinels. Specific focus is given to the role of satellite data synergy in integrated systems for air quality monitoring, in

Analysis on BDS Satellite Internal Multipath and Its Impact on Wide-lane FCB Estimation

Directory of Open Access Journals (Sweden)

RUAN Rengui

2017-08-01

Full Text Available To the issue of the satellite internal multipath (SIMP of BeiDou satellites, it proposed and emphasized that the SIMP model should be established as a function of the nadir angle with respect to the observed satellite rather than the elevation of the measurement, so that it can be used for receivers at various altitude. BDS data from global distributed stations operated by the International Monitoring and Assessment System (iGMAS and the Multi-GNSS Experiment (MGEX of the International GNSS Service (IGS are collected and a new SIMP model as a piece-wise linear function of the nadir angle is released for the IGSO-and MEO-satellite groups and for B1, B2 and B3 frequency band individually. The SIMP of GEO,IGSO and MEO satellites is further analyzed with B1/B2 dual-frequency data onboard the FengYun-3 C(FY3C satellite at an altitude of~830 km, and it showed that, for nadir angles smaller than 7°, the SIMP values for GEO is quite close to the IGSO's, especially for B2, which may suggest that the SIMP model for IGSO satellites possibly also works for GEO satellites. It also demonstrated that, when the nadir angle is smaller than 12°for the MEO and 7°for the IGSO, the estimated SIMP model with data from FY3C is considerable consistent with that estimated with data collected at ground stations. Experiments are carried out to investigate the impacts of the SIMP on wide-lane fractional cycle bias (FCB estimation for BDS satellites. The result indicates that, with the correction of the estimated SIMP, the repeatability of the FCB series is significantly improved by more than 60% for all satellites. Specifically, for the MEO and IGSO satellites, the repeatability is smaller than 0.05 cycle; the repeatability of 0.023 and 0.068 cycles achieved for GEO satellites C01 and C02 respectively with the estimated SIMP model for IGSO satellites.

The American Satellite Company (ASC) satellite deployed from payload bay

Science.gov (United States)

1985-01-01

The American Satellite Company (ASC) communications satellite is deployed from the payload bay of the Shuttle Discovery. A portion of the cloudy surface of the earth can be seen to the left of the frame.

Developing a sustainable satellite-based environmental monitoring system In Nigeria

Science.gov (United States)

Akinyede, J. O.; Adepoju, K. A.; Akinluyi, F. O.; Anifowose, A. Y. B.

2015-10-01

Increased anthropogenic activities over the year have remained a major factor of the Earth changing environment. This phenomenon has given rise to a number of environmental degraded sites that characterize the Nigeria's landscape. The human-induced elements include gully erosion, mangrove ecosystems degradation, desertification and deforestation, particularly in the south east, Niger Delta, north east and south west of Nigeria respectively, as well as river flooding/flood plain inundation and land degradation around Kainji lake area. Because of little or no effective management measures, the attendant environmental hazards have been extremely damaging to the infrastructures and socio-economic development of the affected area. Hence, a concerted effort, through integrated and space-based research, is being intensified to manage and monitor the environment in order to restore the stability, goods and services of the environment. This has justified Nigeria's investment in its space programme, especially the launch of NigeriaSat-1, an Earth observation micro-satellite in constellation with five (5) other similar satellites, Alsat-1, China DMC, Bilsat-1, DEMOS and UK DMC belonging to Algeria, China, Turkey, Spain and United Kingdom respectively. The use of data from these satellites, particularly NigeriaSat-1, in conjunction with associated technologies has proved to be very useful in understanding the influence of both natural and human activities on the Nigeria's ecosystems and environment. The results of some researches on specific applications of Nigerian satellites are presented in this paper. Appropriate sustainable land and water resources management in the affected areas, based on Nigeria's satellite data capture and integration, are also discussed.

Systèmes coopératifs hybride Satellite-Terrestre : analyse de performance et dimensionnement du système

OpenAIRE

Sreng, Sokchenda

2012-01-01

Les systèmes de communications par satellite sont utilisés dans le contexte de la radiodiffusion, de la navigation, du sauvetage et du secours aux sinistrés, car ils permettent de fournir des services sur une large zone de couverture. Cependant, cette zone de couverture est limitée par l'effet de masquage provoqué par des obstacles qui bloquent la liaison directe entre le satellite et un utilisateur terrestre. L'effet de masquage devient plus sévère en cas de satellites à faibles angles d'élé...

Trends in mobile satellite communication

Science.gov (United States)

Johannsen, Klaus G.; Bowles, Mike W.; Milliken, Samuel; Cherrette, Alan R.; Busche, Gregory C.

1993-01-01

Ever since the U.S. Federal Communication Commission opened the discussion on spectrum usage for personal handheld communication, the community of satellite manufacturers has been searching for an economically viable and technically feasible satellite mobile communication system. Hughes Aircraft Company and others have joined in providing proposals for such systems, ranging from low to medium to geosynchronous orbits. These proposals make it clear that the trend in mobile satellite communication is toward more sophisticated satellites with a large number of spot beams and onboard processing, providing worldwide interconnectivity. Recent Hughes studies indicate that from a cost standpoint the geosynchronous satellite (GEOS) is most economical, followed by the medium earth orbit satellite (MEOS) and then by the low earth orbit satellite (LEOS). From a system performance standpoint, this evaluation may be in reverse order, depending on how the public will react to speech delay and collision. This paper discusses the trends and various mobile satellite constellations in satellite communication under investigation. It considers the effect of orbital altitude and modulation/multiple access on the link and spacecraft design.

JPSS Preparations at the Satellite Proving Ground for Marine, Precipitation, and Satellite Analysis

Science.gov (United States)

Folmer, Michael J.; Berndt, E.; Clark, J.; Orrison, A.; Kibler, J.; Sienkiewicz, J.; Nelson, J.; Goldberg, M.; Sjoberg, W.

2016-01-01

The ocean prediction center at the national hurricane center's tropical analysis and forecast Branch, the Weather Prediction center and the Satellite analysis branch of NESDIS make up the Satellite Proving Ground for Marine, Precipitation and Satellite Analysis. These centers had early exposure to JPSS products using the S-NPP Satellite that was launched in 2011. Forecasters continue to evaluate new products in anticipation for the launch of JPSS-1 sometime in 2017.

Anik-E1 and E2 satellite failures of January 1994 revisited

Science.gov (United States)

Lam, H.-L.; Boteler, D. H.; Burlton, B.; Evans, J.

2012-10-01

The consecutive failures of the geosynchronous Anik-E1 communication satellite on January 20, 1994, and Anik-E2 about nine hours later on January 21 (both incidents occurred on January 20 local time) received considerable publicity because the malfunctions of the satellites disrupted television and computer data transmissions across Canada, as well as telephone services to remote northern communities for hours. This often-cited event is revisited here with materials not covered before. Using publicly available information, Anik-E failure details, media coverage, recovery effort and cost incurred are first presented. This is then followed by scrutiny of space weather conditions pertinent to the occurrences of the Anik-E upsets. We trace the space weather episode's inception on the Sun, propagation through interplanetary medium, and manifestation in magnetic field variations as well as in energetic electron flux increases, and its eventual impact on the Anik-Es. The genesis of the energetic electron enhancements that have been blamed for the satellite malfunctions is thus traceable via high-speed solar wind stream with Alfven wave fluctuations to a longitudinally wide coronal hole on the Sun. Furthermore, strong magnetic pulsations preceding electron flux peaks indicate Pc5 ULF (Ultra Low Frequency) waves as a probable acceleration mechanism for the energetic electron flux enhancement that resulted in the internal charging of the Anik-Es. The magnetic fluctuations may even be possible triggers for the subsequent discharge that caused the satellites to malfunction. This incident illustrates that satellite operators should be on alert for elevated high-energy electron environment that is above established thresholds, as specifications in satellite design may not render a satellite immune from internal charging.

Propagation Measurement on Earth-Sky Signal Effects for High Speed Train Satellite Channel in Tropical Region at Ku-Band

Directory of Open Access Journals (Sweden)

Abdulmajeed H. J. Al-Jumaily

2015-01-01

Full Text Available Recent advances in satellite communication technologies in the tropical regions have led to significant increase in the demand for services and applications that require high channel quality for mobile satellite terminals. Determination and quantification of these requirements are important to optimize service quality, particularly in the Malaysian region. Moreover, the tests on current satellite propagation models were carried out at temperate regions whose environmental characteristics are much different from those in Malaysia. This difference renders these propagation models inapplicable and irrelevant to tropical regions in general. This paper presents the link characteristics observations and performance analysis with propagation measurements done in tropical region to provide an accurate database regarding rain and power arches supply (PAs attenuations in the tropics for mobile scenarios. Hence, an extension for improving the performance assessment and analysis of satellite/transmission has been achieved. The Malaysia propagation measurement for mobile scenario (Malaysia-PMMS enables first-hand coarse estimation and attenuation analysis, because the attenuation resulting from rain and PAs becomes easily amenable for measurement. Parallel to that, the measured attenuation has been compared with that of the simulated output at noise floor level. The underlying analytical tool is validated by measurements specific at tropical region, for dynamic model of mobile satellite links operating at higher than 10 GHz.

20 Years Experience with using Low Cost Launch Opportunities for 20 Small Satellite Missions

Science.gov (United States)

Meerman, Maarten; Sweeting, Martin, , Sir

these larger 'small satellites' are too big to be carried 'piggy-back'. The entrepreneurial efforts of leading FSU rocket &missile organisations in converting existing vehicles to meet the small satellite launch market at an appropriate cost has resulted in the FSU now holding the prime position for providing launches for the small satellite community - and with an excellent track record of successful launches. However, negotiating and completing a Launch Services Agreement (LSA) for a nano-micro-minisatellite with any launcher organisation is a complex matter and risky territory for the unwary or inexperienced who may easily fall prey to unexpected additional costs and delays. Whilst this warning should be heeded when dealing with European and US organisations, it is particularly relevant when negotiating launches from the FSU where there is a plethora of agencies and organisations offering a bewildering range of launch vehicles and options. Furthermore, the FSU has developed a very different technical and managerial philosophy towards launchers when compared with the west and this can be unnerving to 'first-time buyers'. Organisations experienced in dealing in the FSU will encounter a different but excellent service - once the launch service agreement has been thoroughly and fiercely negotiated in every detail. The inexperienced, however, have encountered frustrating delays, lost opportunities, unexpected taxes and costs for additional services or facilities not originally specified, and bewilderment at the different procedures used in the FSU. Fortunately, all this can be avoided with proper experience and the FSU is the current mainstay for launching small satellites quickly, affordably and reliably. Surrey has unique experience gathered over 20 years in handling launches for 20 small satellites, ranging from a 6kg nanosatellite, 50-100kg microsatellites, and a 325kg minisatellite, using 7 different launchers from the USA, Russia, Ukraine, and Europe. By working

Second-generation mobile satellite system. A conceptual design and trade-off study

Science.gov (United States)

Sue, M. K.; Park, Y. H.

1985-01-01

In recent years, interest has grown in the mobile satellite (MSAT) system, a satellite-based communications system capable of providing integrated voice and data services to a large number of users. To explore the potential of a commercial mobile satellite system (MSS) beyond the horizon of the first generation, using technologies of the 1990's and to assist MSAT-X in directing its efforts, a conceptual design has been performed for a second-generation system to be launched around the mid-1990's. The design goal is to maximize the number of satellite channels and/or minimize the overall life-cycle cost, subject to the constraint of utilizing a commercial satellite bus with minimum modifications. To provide an optimal design, a series of trade-offs are performed, including antenna sizing, feed configurations, and interference analysis. Interference is a serious problem for MSAT and often an overlapping feed design is required to reduce interbeam interference. The trade-off studies will show that a simple non-overlapping feed is sufficient for the second-generation system, thus avoiding the need for the complicated beam-forming network that is associated with the overlapping feed designs. In addition, a system that operates at L-band, an alternative frequency band that is being considered by some for possible MSAT applications, is also presented.

76 FR 31252 - Fixed and Mobile Services in the Mobile Satellite Service Bands at 1525-1559 MHz and 1626.5-1660...

Science.gov (United States)

2011-05-31

... operations in the L-band on GPS and other Global Navigation Satellite System (GNSS) receivers. 24. The... and NTIA about LightSquared's operations in the MSS L-band, LightSquared is working with the GPS... from its base station operations in the MSS L-band spectrum to GPS receivers in the adjacent 1559-1610...

LMSS SERVICES FINANCIAL REPORT PROGRAM

Science.gov (United States)

Chamberlain, R. G.

1994-01-01

The objective of this Services Finance Report program is to provide a means for comparing alternative designs of LMSS systems or other services systems. This program is actually a Multiplan worksheet. The labels used in the worksheet were chosen for a satellite-based cellular communication service (LMSS - Land Mobile Satellite System) but the analysis is not restricted to such cases. A comprehensive financial model is used to calculate a 'figure of merit' which can be used to compare effects of equipment and operating costs, pricing strategy, and customer demand for different systems. The program also calculates the price that a company would have to charge customers to meet all its expenses and make a specified profit. A price estimate can be obtained for almost any service which is heavily dependent on capital investment and which has operating costs that depend on the amount of service sold. The economic analysis has two main components: supplier finances and customer finances. Supplier finances include amortization, interest, insurance, taxes, and operating and maintenance expenses. Customer finances include usage rate, subscription fees, equipment costs, and estimated traffic. Prices can defined as real or nominal to account for effects of escalation and inflation, and the profits can be regulated or unrestricted This program is written for interactive execution with Multiplan (version 1.2) and has been implemented on an IBM PC series computer operating under DOS (version 2.11). The LMSS worksheet has a space requirement of approximately 38K of 8 bit bytes. This worksheet was developed in 1984.

Access NASA Satellite Global Precipitation Data Visualization on YouTube

Science.gov (United States)

Liu, Z.; Su, J.; Acker, J. G.; Huffman, G. J.; Vollmer, B.; Wei, J.; Meyer, D. J.

2017-12-01

Since the satellite era began, NASA has collected a large volume of Earth science observations for research and applications around the world. Satellite data at 12 NASA data centers can also be used for STEM activities such as disaster events, climate change, etc. However, accessing satellite data can be a daunting task for non-professional users such as teachers and students because of unfamiliarity of terminology, disciplines, data formats, data structures, computing resources, processing software, programing languages, etc. Over the years, many efforts have been developed to improve satellite data access, but barriers still exist for non-professionals. In this presentation, we will present our latest activity that uses the popular online video sharing web site, YouTube, to access visualization of global precipitation datasets at the NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC). With YouTube, users can access and visualize a large volume of satellite data without necessity to learn new software or download data. The dataset in this activity is the 3-hourly TRMM (Tropical Rainfall Measuring Mission) Multi-satellite Precipitation Analysis (TMPA). The video consists of over 50,000 data files collected since 1998 onwards, covering a zone between 50°N-S. The YouTube video will last 36 minutes for the entire dataset record (over 19 years). Since the time stamp is on each frame of the video, users can begin at any time by dragging the time progress bar. This precipitation animation will allow viewing precipitation events and processes (e.g., hurricanes, fronts, atmospheric rivers, etc.) on a global scale. The next plan is to develop a similar animation for the GPM (Global Precipitation Measurement) Integrated Multi-satellitE Retrievals for GPM (IMERG). The IMERG provides precipitation on a near-global (60°N-S) coverage at half-hourly time interval, showing more details on precipitation processes and development, compared to the 3

The Future of Satellite Communications Technology.

Science.gov (United States)

Nowland, Wayne

1985-01-01

Discusses technical advances in satellite technology since the 1960s, and the International Telecommunications Satellite Organization's role in these developments; describes how AUSSAT, Australia's domestic satellite system, exemplifies the latest developments in satellite technology; and reviews satellite system features, possible future…

CMR Catalog Service for the Web

Science.gov (United States)

Newman, Doug; Mitchell, Andrew

2016-01-01

With the impending retirement of Global Change Master Directory (GCMD) Application Programming Interfaces (APIs) the Common Metadata Repository (CMR) was charged with providing a collection-level Catalog Service for the Web (CSW) that provided the same level of functionality as GCMD. This talk describes the capabilities of the CMR CSW API with particular reference to the support of the Committee on Earth Observation Satellites (CEOS) Working Group on Information Systems and Services (WGISS) Integrated Catalog (CWIC).

Contrast in low-cost operational concepts for orbiting satellites

Science.gov (United States)

Walyus, Keith D.; Reis, James; Bradley, Arthur J.

2002-12-01

Older spacecraft missions, especially those in low Earth orbit with telemetry intensive requirements, required round-the-clock control center staffing. The state of technology relied on control center personnel to continually examine data, make decisions, resolve anomalies, and file reports. Hubble Space Telescope (HST) is a prime example of this description. Technological advancements in hardware and software over the last decade have yielded increases in productivity and operational efficiency, which result in lower cost. The re-engineering effort of HST, which has recently concluded, utilized emerging technology to reduce cost and increase productivity. New missions, of which NASA's Transition Region and Coronal Explorer Satellite (TRACE) is an example, have benefited from recent technological advancements and are more cost-effective than when HST was first launched. During its launch (1998) and early orbit phase, the TRACE Flight Operations Team (FOT) employed continually staffed operations. Yet once the mission entered its nominal phase, the FOT reduced their staffing to standard weekday business hours. Operations were still conducted at night and during the weekends, but these operations occurred autonomously without compromising their high standards for data collections. For the HST, which launched in 1990, reduced cost operations will employ a different operational concept, when the spacecraft enters its low-cost phase after its final servicing mission in 2004. Primarily due to the spacecraft"s design, the HST Project has determined that single-shift operations will introduce unacceptable risks for the amount of dollars saved. More importantly, significant cost-savings can still be achieved by changing the operational concept for the FOT, while still maintaining round-the-clock staffing. It"s important to note that the low-cost solutions obtained for one satellite may not be applicable for other satellites. This paper will contrast the differences between

Attitude control for on-orbit servicing spacecraft using hybrid actuator

Science.gov (United States)

Wu, Yunhua; Han, Feng; Zheng, Mohong; He, Mengjie; Chen, Zhiming; Hua, Bing; Wang, Feng

2018-03-01

On-orbit servicing is one of the research hotspots of space missions. A small satellite equipped with multiple robotic manipulators is expected to carry out device replacement task for target large spacecraft. Attitude hyperstable control of a small satellite platform under rotations of the manipulators is a challenging problem. A hybrid momentum exchanging actuator consists of Control Moment Gyro (CMG) and Reaction Wheel (RW) is proposed to tackle the above issue, due to its huge amount of momentum storage capacity of the CMG and high control accuracy of the RW, in which the CMG produces large command torque while the RW offers additional control degrees. The constructed dynamic model of the servicing satellite advises that it's feasible for attitude hyperstable control of the platform with arbitrary manipulators through compensating the disturbance generated by rapid rotation of the manipulators. Then, null motion between the CMG and RW is exploited to drive the system to the expected target with favorable performance, and to overcome the CMG inherent geometric singularity and RW saturation. Simulations with different initial situations, including CMG hyperbolic and elliptic singularities and RW saturation, are executed. Compared to the scenarios where the CMG or RW fails stabilizing the platform, large control torque, precise control effect and escape of singularity are guaranteed by the introduced hybrid actuator, CMGRW (CMGRW refers to the hybrid momentum exchanging devices in this paper, consisting of 4 CMGs in classical pyramid cluster and 3 RWs in an orthogonal group (specific description can been found in Section 4)). The feasible performance of the satellite, CMG and RW under large disturbance demonstrates that the control architecture proposed is capable of attitude control for on-orbit servicing satellite with multiple robotic manipulators.

Cooperative and cognitive satellite systems

CERN Document Server

Chatzinotas, Symeon; De Gaudenzi, Riccardo

2015-01-01

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

Review: advances in in situ and satellite phenological observations in Japan

Science.gov (United States)

Nagai, Shin; Nasahara, Kenlo Nishida; Inoue, Tomoharu; Saitoh, Taku M.; Suzuki, Rikie

2016-04-01

To accurately evaluate the responses of spatial and temporal variation of ecosystem functioning (evapotranspiration and photosynthesis) and services (regulating and cultural services) to the rapid changes caused by global warming, we depend on long-term, continuous, near-surface, and satellite remote sensing of phenology over wide areas. Here, we review such phenological studies in Japan and discuss our current knowledge, problems, and future developments. In contrast with North America and Europe, Japan has been able to evaluate plant phenology along vertical and horizontal gradients within a narrow area because of the country's high topographic relief. Phenological observation networks that support scientific studies and outreach activities have used near-surface tools such as digital cameras and spectral radiometers. Differences in phenology among ecosystems and tree species have been detected by analyzing the seasonal variation of red, green, and blue digital numbers (RGB values) extracted from phenological images, as well as spectral reflectance and vegetation indices. The relationships between seasonal variations in RGB-derived indices or spectral characteristics and the ecological and CO2 flux measurement data have been well validated. In contrast, insufficient satellite remote-sensing observations have been conducted because of the coarse spatial resolution of previous datasets, which could not detect the heterogeneous plant phenology that results from Japan's complex topography and vegetation. To improve Japanese phenological observations, multidisciplinary analysis and evaluation will be needed to link traditional phenological observations with "index trees," near-surface and satellite remote-sensing observations, "citizen science" (observations by citizens), and results published on the Internet.

Thematic mapping from satellite imagery

CERN Document Server

Denègre, J

2013-01-01

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

Space Weather Services of Korea

Science.gov (United States)

Yoon, K.; Hong, S.; Jangsuk, C.; Dong Kyu, K.; Jinyee, C.; Yeongoh, C.

2016-12-01

The Korean Space Weather Center (KSWC) of the National Radio Research Agency (RRA) is a government agency which is the official source of space weather information for Korean Government and the primary action agency of emergency measure to severe space weather condition. KSWC's main role is providing alerts, watches, and forecasts in order to minimize the space weather impacts on both of public and commercial sectors of satellites, aviation, communications, navigations, power grids, and etc. KSWC is also in charge of monitoring the space weather condition and conducting research and development for its main role of space weather operation in Korea. In this study, we will present KSWC's recent efforts on development of application-oriented space weather research products and services on user needs, and introduce new international collaborative projects, such as IPS-Driven Enlil model, DREAM model estimating electron in satellite orbit, global network of DSCOVR and STEREO satellites tracking, and ARMAS (Automated Radiation Measurement for Aviation Safety).

LauncherOne: Virgin Orbit's Dedicated Launch Vehicle for Small Satellites & Impact to the Space Enterprise Vision

Science.gov (United States)

Vaughn, M.; Kwong, J.; Pomerantz, W.

Virgin Orbit is developing a space transportation service to provide an affordable, reliable, and responsive dedicated ride to orbit for smaller payloads. No longer will small satellite users be forced to make a choice between accepting the limitations of flight as a secondary payload, paying dramatically more for a dedicated launch vehicle, or dealing with the added complexity associated with export control requirements and international travel to distant launch sites. Virgin Orbit has made significant progress towards first flight of a new vehicle that will give satellite developers and operators a better option for carrying their small satellites into orbit. This new service is called LauncherOne (See the figure below). LauncherOne is a two stage, air-launched liquid propulsion (LOX/RP) rocket. Air launched from a specially modified 747-400 carrier aircraft (named “Cosmic Girl”), this system is designed to conduct operations from a variety of locations, allowing customers to select various launch azimuths and increasing available orbital launch windows. This provides small satellite customers an affordable, flexible and dedicated option for access to space. In addition to developing the LauncherOne vehicle, Virgin Orbit has worked with US government customers and across the new, emerging commercial sector to refine concepts for resiliency, constellation replenishment and responsive launch elements that can be key enables for the Space Enterprise Vision (SEV). This element of customer interaction is being led by their new subsidiary company, VOX Space. This paper summarizes technical progress made on LauncherOne in the past year and extends the thinking of how commercial space, small satellites and this new emerging market can be brought to bear to enable true space system resiliency.

A new antenna concept for satellite communications

Science.gov (United States)

Skahill, G.; Ciccolella, D.

1982-01-01

A novel antenna configuration of two reflecting surfaces and a phased array is examined for application to satellite communications and shown to be superior in every respect to earlier designs for service to the continental United States from synchronous orbit. The vignetting that afflicts other two reflector optical systems is eliminated by use of a reflecting field element. The remaining aberrations, predominantly coma, are isolated in the time delay distribution at the surface of the array and can be compensated by ordinary array techniques. The optics exhibits infinite bandwidth and the frequency range is limited only by the design of the array.

The Copernicus POD Service and beyond: Scientific exploitation of the orbit-related data and products

Science.gov (United States)

Peter, Heike; Fernández, Jaime; Fernández, Carlos; Féménias, Pierre

2017-04-01

The Copernicus POD (Precise Orbit Determination) Service is part of the Copernicus Processing Data Ground Segment (PDGS) of the Sentinel-1, -2 and -3 missions. A GMV-led consortium is operating the Copernicus POD Service being in charge of generating precise orbital products and auxiliary data files for their use as part of the processing chains of the respective Sentinel PDGS. The orbital products are available through the dedicated Copernicus data hub. The Copernicus POD Service is supported by the Copernicus POD Quality Working Group (QWG) for the validation of the orbit product accuracy. The QWG is delivering independent orbit solutions for the satellites. The cross-comparison of all these orbit solutions is essential to monitor and to improve the orbit accuracy because for Sentinel-1 and -2 this is the only possibility to externally assess the quality of the orbits. Each of the Sentinel-1, -2, and -3 satellites carries dual-frequency GPS receivers delivering the necessary measurements for the precise orbit determination of the satellites. The Sentinel-3 satellites are additionally equipped with a DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite) receiver and a Laser Retro Reflector for Satellite Laser Ranging. These two additional observation techniques allow for independent validation of the GPS-derived orbit determination results and for studying biases between the different techniques. The scientific exploitation of the orbit determination and the corresponding input data is manifold. Sophisticated satellite macro models improve the modelling of the non-gravitational forces acting on the satellite. On the other hand, comparisons to orbits based on pure empirical modelling of the non-gravitational forces help to sort out deficiencies in the satellite geometry information. The dual-frequency GPS data delivered by the satellites can give valuable input for ionospheric studies important for Space Weather research. So-called kinematic

Signalling design and architecture for a proposed mobile satellite network

Science.gov (United States)

Yan, T.-Y.; Cheng, U.; Wang, C.

1990-01-01

In a frequency-division/demand-assigned multiple-access (FD/DAMA) architecture, each mobile subscriber must make a connection request to the Network Management Center before transmission for either open-end or closed-end services. Open-end services are for voice calls and long file transfer and are processed on a blocked-call-cleared basis. Closed-end services are for transmitting burst data and are processed on a first-come first-served basis. This paper presents the signalling design and architecture for non-voice services of an FD/DAMA mobile satellite network. The connection requests are made through the recently proposed multiple channel collision resolution scheme which provides a significantly higher throughput than the traditional slotted ALOHA scheme. For non-voice services, it is well known that retransmissions are necessary to ensure the delivery of a message in its entirety from the source to destination. Retransmission protocols for open-end and closed-end data transfer are investigated. The signal structure for the proposed network is derived from X-25 standards with appropriate modifications. The packet types and their usages are described in this paper.

UHF coplanar-slot antenna for aircraft-to-satellite data communications

Science.gov (United States)

Myhre, R. W.

1979-01-01

The initiative for starting the Aircraft-to-Satellite Data Relay (ASDAR) Program came from a recognition that much of the world's weather originates in the data sparse area of the tropics which are primarily ocean. The ASDAR system consists of (1) a data acquisition and control unit to acquire, store and format these data; (2) a clock to time the data sampling and transmission periods; and (3) a transmitter and low-profile upper hemisphere coverage antenna to relay the formatted data via satellite to the National Weather Service ground stations, as shown schematically. The low-profile antenna is a conformal antenna based on the coplanar-slot approach. The antenna is circular polarized and has an on-axis gain of nearly 2.5 dB and a HPBW greater than 90 deg. The discussion covers antenna design, radiation characteristics, flight testing, and system performance.

Polar-Orbiting Satellite (POES) Images

Data.gov (United States)

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...

The Eccentric Satellites Problem: Comparing Milky Way Satellite Orbital Properties to Simulation Results

Science.gov (United States)

Haji, Umran; Pryor, Carlton; Applebaum, Elaad; Brooks, Alyson

2018-01-01

We compare the orbital properties of the satellite galaxies of the Milky Way to those of satellites found in simulated Milky Way-like systems as a means of testing cosmological simulations of galaxy formation. The particular problem that we are investigating is a discrepancy in the distribution of orbital eccentricities. Previous studies of Milky Way-mass systems analyzed in a semi-analytic ΛCDM cosmological model have found that the satellites tend to have significantly larger fractions of their kinetic energy invested in radial motion with respect to their central galaxy than do the real-world Milky Way satellites. We analyze several high-resolution ("zoom-in") hydrodynamical simulations of Milky Way-mass galaxies and their associated satellite systems to investigate why previous works found Milky Way-like systems to be rare. We find a possible relationship between a quiescent galactic assembly history and a distribution of satellite kinematics resembling that of the Milky Way. This project has been supported by funding from National Science Foundation grant PHY-1560077.

Performance Analysis of Space Information Networks with Backbone Satellite Relaying for Vehicular Networks

Directory of Open Access Journals (Sweden)

Jian Jiao

2017-01-01

Full Text Available Space Information Network (SIN with backbone satellites relaying for vehicular network (VN communications is regarded as an effective strategy to provide diverse vehicular services in a seamless, efficient, and cost-effective manner in rural areas and highways. In this paper, we investigate the performance of SIN return channel cooperative communications via an amplify-and-forward (AF backbone satellite relaying for VN communications, where we assume that both of the source-destination and relay-destination links undergo Shadowed-Rician fading and the source-relay link follows Rician fading, respectively. In this SIN-assisted VN communication scenario, we first obtain the approximate statistical distributions of the equivalent end-to-end signal-to-noise ratio (SNR of the system. Then, we derive the closed-form expressions to efficiently evaluate the average symbol error rate (ASER of the system. Furthermore, the ASER expressions are taking into account the effect of satellite perturbation of the backbone relaying satellite, which reveal the accumulated error of the antenna pointing error. Finally, simulation results are provided to verify the accuracy of our theoretical analysis and show the impact of various parameters on the system performance.

Providing Access and Visualization to Global Cloud Properties from GEO Satellites

Science.gov (United States)

Chee, T.; Nguyen, L.; Minnis, P.; Spangenberg, D.; Palikonda, R.; Ayers, J. K.

2015-12-01

Providing public access to cloud macro and microphysical properties is a key concern for the NASA Langley Research Center Cloud and Radiation Group. This work describes a tool and method that allows end users to easily browse and access cloud information that is otherwise difficult to acquire and manipulate. The core of the tool is an application-programming interface that is made available to the public. One goal of the tool is to provide a demonstration to end users so that they can use the dynamically generated imagery as an input into their own work flows for both image generation and cloud product requisition. This project builds upon NASA Langley Cloud and Radiation Group's experience with making real-time and historical satellite cloud product imagery accessible and easily searchable. As we see the increasing use of virtual supply chains that provide additional value at each link there is value in making satellite derived cloud product information available through a simple access method as well as allowing users to browse and view that imagery as they need rather than in a manner most convenient for the data provider. Using the Open Geospatial Consortium's Web Processing Service as our access method, we describe a system that uses a hybrid local and cloud based parallel processing system that can return both satellite imagery and cloud product imagery as well as the binary data used to generate them in multiple formats. The images and cloud products are sourced from multiple satellites and also "merged" datasets created by temporally and spatially matching satellite sensors. Finally, the tool and API allow users to access information that spans the time ranges that our group has information available. In the case of satellite imagery, the temporal range can span the entire lifetime of the sensor.

Data Mining Web Services for Science Data Repositories

Science.gov (United States)

Graves, S.; Ramachandran, R.; Keiser, K.; Maskey, M.; Lynnes, C.; Pham, L.

2006-12-01

The maturation of web services standards and technologies sets the stage for a distributed "Service-Oriented Architecture" (SOA) for NASA's next generation science data processing. This architecture will allow members of the scientific community to create and combine persistent distributed data processing services and make them available to other users over the Internet. NASA has initiated a project to create a suite of specialized data mining web services designed specifically for science data. The project leverages the Algorithm Development and Mining (ADaM) toolkit as its basis. The ADaM toolkit is a robust, mature and freely available science data mining toolkit that is being used by several research organizations and educational institutions worldwide. These mining services will give the scientific community a powerful and versatile data mining capability that can be used to create higher order products such as thematic maps from current and future NASA satellite data records with methods that are not currently available. The package of mining and related services are being developed using Web Services standards so that community-based measurement processing systems can access and interoperate with them. These standards-based services allow users different options for utilizing them, from direct remote invocation by a client application to deployment of a Business Process Execution Language (BPEL) solutions package where a complex data mining workflow is exposed to others as a single service. The ability to deploy and operate these services at a data archive allows the data mining algorithms to be run where the data are stored, a more efficient scenario than moving large amounts of data over the network. This will be demonstrated in a scenario in which a user uses a remote Web-Service-enabled clustering algorithm to create cloud masks from satellite imagery at the Goddard Earth Sciences Data and Information Services Center (GES DISC).

Satellite switched FDMA advanced communication technology satellite program

Science.gov (United States)

Atwood, S.; Higton, G. H.; Wood, K.; Kline, A.; Furiga, A.; Rausch, M.; Jan, Y.

1982-01-01

The satellite switched frequency division multiple access system provided a detailed system architecture that supports a point to point communication system for long haul voice, video and data traffic between small Earth terminals at Ka band frequencies at 30/20 GHz. A detailed system design is presented for the space segment, small terminal/trunking segment at network control segment for domestic traffic model A or B, each totaling 3.8 Gb/s of small terminal traffic and 6.2 Gb/s trunk traffic. The small terminal traffic (3.8 Gb/s) is emphasized, for the satellite router portion of the system design, which is a composite of thousands of Earth stations with digital traffic ranging from a single 32 Kb/s CVSD voice channel to thousands of channels containing voice, video and data with a data rate as high as 33 Mb/s. The system design concept presented, effectively optimizes a unique frequency and channelization plan for both traffic models A and B with minimum reorganization of the satellite payload transponder subsystem hardware design. The unique zoning concept allows multiple beam antennas while maximizing multiple carrier frequency reuse. Detailed hardware design estimates for an FDMA router (part of the satellite transponder subsystem) indicate a weight and dc power budget of 353 lbs, 195 watts for traffic model A and 498 lbs, 244 watts for traffic model B.

Partnership via Satellite.

Science.gov (United States)

Powell, Marie Clare

1980-01-01

Segments of the 1980 National Catholic Educational Association (NCEA) conference were to be telecast nationally by satellite. The author briefly explains the satellite transmission process and advises Catholic educators on how to pick up the broadcast through their local cable television system. (SJL)

A Quality Screening Service for Remote Sensing Data

Science.gov (United States)

Lynnes, Christopher; Olsen, Edward; Fox, Peter; Vollmer, Bruce; Wolfe, Robert; Samadi, Shahin

2010-01-01

NASA provides a wide variety of Earth-observing satellite data products to a diverse community. These data are annotated with quality information in a variety of ways, with the result that many users struggle to understand how to properly account for quality when dealing with satellite data. To address this issue, a Data Quality Screening Service (DQSS) is being implemented for a number of datasets. The DQSS will enable users to obtain data files in which low-quality pixels have been filtered out, based either on quality criteria recommended by the science team or on the user s particular quality criteria. The objective is to increase proper utilization of this critical quality data in science data analysis of satellite data products.

Satellite Servicing's Autonomous Rendezvous and Docking Testbed on the International Space Station

Science.gov (United States)

Naasz, Bo J.; Strube, Matthew; Van Eepoel, John; Barbee, Brent W.; Getzandanner, Kenneth M.

2011-01-01

The Space Servicing Capabilities Project (SSCP) at NASA's Goddard Space Flight Center (GSFC) has been tasked with developing systems for servicing space assets. Starting in 2009, the SSCP completed a study documenting potential customers and the business case for servicing, as well as defining several notional missions and required technologies. In 2010, SSCP moved to the implementation stage by completing several ground demonstrations and commencing development of two International Space Station (ISS) payloads-the Robotic Refueling Mission (RRM) and the Dextre Pointing Package (DPP)--to mitigate new technology risks for a robotic mission to service existing assets in geosynchronous orbit. This paper introduces the DPP, scheduled to fly in July of 2012 on the third operational SpaceX Dragon mission, and its Autonomous Rendezvous and Docking (AR&D) instruments. The combination of sensors and advanced avionics provide valuable on-orbit demonstrations of essential technologies for servicing existing vehicles, both cooperative and non-cooperative.

A vigorous approach to customer service.

Science.gov (United States)

Pollock, E K

1993-01-01

PPG Industries, Inc. is the world's largest supplier of automotive original coatings. Its business-to-business customers require individualized service based on specific requirements. The company has solidified these relationships by establishing satellite supply facilities, applying the quality process to problem solving, and providing a variety of outlets for customer feedback.

Spectrum and power allocation in cognitive multi-beam satellite communications with flexible satellite payloads

Science.gov (United States)

Liu, Zhihui; Wang, Haitao; Dong, Tao; Yin, Jie; Zhang, Tingting; Guo, Hui; Li, Dequan

2018-02-01

In this paper, the cognitive multi-beam satellite system, i.e., two satellite networks coexist through underlay spectrum sharing, is studied, and the power and spectrum allocation method is employed for interference control and throughput maximization. Specifically, the multi-beam satellite with flexible payload reuses the authorized spectrum of the primary satellite, adjusting its transmission band as well as power for each beam to limit its interference on the primary satellite below the prescribed threshold and maximize its own achievable rate. This power and spectrum allocation problem is formulated as a mixed nonconvex programming. For effective solving, we first introduce the concept of signal to leakage plus noise ratio (SLNR) to decouple multiple transmit power variables in the both objective and constraint, and then propose a heuristic algorithm to assign spectrum sub-bands. After that, a stepwise plus slice-wise algorithm is proposed to implement the discrete power allocation. Finally, simulation results show that adopting cognitive technology can improve spectrum efficiency of the satellite communication.

Precise Orbit Determination of GPS Satellites Using Phase Observables

Directory of Open Access Journals (Sweden)

Myung-Kook Jee

1997-12-01

Full Text Available The accuracy of user position by GPS is heavily dependent upon the accuracy of satellite position which is usually transmitted to GPS users in radio signals. The real-time satellite position information directly obtained from broadcast ephimerides has the accuracy of 3 x 10 meters which is very unsatisfactory to measure 100km baseline to the accuracy of less than a few mili-meters. There are globally at present seven orbit analysis centers capable of generating precise GPS ephimerides and their orbit quality is of the order of about 10cm. Therefore, precise orbit model and phase processing technique were reviewed and consequently precise GPS ephimerides were produced after processing the phase observables of 28 global GPS stations for 1 day. Initial 6 orbit parameters and 2 solar radiation coefficients were estimated using batch least square algorithm and the final results were compared with the orbit of IGS, the International GPS Service for Geodynamics.

Concept for a Satellite-Based Advanced Air Traffic Management System : Volume 4. Operational Description and Qualitative Assessment.

Science.gov (United States)

1974-02-01

The volume presents a description of how the Satellite-Based Advanced Air Traffic Management System (SAATMS) operates and a qualitative assessment of the system. The operational description includes the services, functions, and tasks performed by the...

Satellite navigation—Amazing technology but insidious risk: Why everyone needs to understand space weather

Science.gov (United States)

Hapgood, Mike

2017-04-01

Global navigation satellite systems (GNSS) are one of the technological wonders of the modern world. Popularly known as satellite navigation, these systems have provided global access to precision location and timing services and have thereby stimulated advances in industry and consumer services, including all forms of transport, telecommunications, financial trading, and even the synchronization of power grids. But this wonderful technology is at risk from natural phenomena in the form of space weather. GNSS signals experience a slight delay as they pass through the ionosphere. This delay varies with space weather conditions and is the most significant source of error for GNSS. Scientific efforts to correct these errors have stimulated billions of dollars of investment in systems that provide accurate correction data for suitably equipped GNSS receivers in a growing number of regions around the world. This accuracy is essential for GNSS use by aircraft and ships. Space weather also provides a further occasional but severe risk to GNSS: an extreme space weather event may deny access to GNSS as ionospheric scintillation scrambles the radio signals from satellites, and rapid ionospheric changes outstrip the ability of error correction systems to supply accurate corrections. It is vital that GNSS users have a backup for such occasions, even if it is only to hunker down and weather the storm.

Emergency Response Damage Assessment using Satellite Remote Sensing Data

Science.gov (United States)

Clandillon, Stephen; Yésou, Hervé; Schneiderhan, Tobias; de Boissezon, Hélène; de Fraipont, Paul

2013-04-01

During disasters rescue and relief organisations need quick access to reliable and accurate information to be better equipped to do their job. It is increasingly felt that satellites offer a unique near real time (NRT) tool to aid disaster management. A short introduction to the International Charter 'Space and Major Disasters', in operation since 2000 promoting worldwide cooperation among member space agencies, will be given as it is the foundation on which satellite-based, emergency response, damage assessment has been built. Other complementary mechanisms will also be discussed. The user access, triggering mechanism, an essential component for this user-driven service, will be highlighted with its 24/7 single access point. Then, a clear distinction will be made between data provision and geo-information delivery mechanisms to underline the user need for geo-information that is easily integrated into their working environments. Briefly, the path to assured emergency response product quality will be presented beginning with user requirements, expressed early-on, for emergency response value-adding services. Initiatives were then established, supported by national and European institutions, to develop the sector, with SERTIT and DLR being key players, providing support to decision makers in headquarters and relief teams in the field. To consistently meet the high quality levels demanded by users, rapid mapping has been transformed via workflow and quality control standardisation to improve both speed and quality. As such, SERTIT located in Alsace, France, and DLR/ZKI from Bavaria, Germany, join their knowledge in this presentation to report about recent standards as both have ISO certified their rapid mapping services based on experienced, well-trained, 24/7 on-call teams and established systems providing the first crisis analysis product in 6 hours after satellite data reception. The three main product types provided are then outlined: up-to-date pre

The Skeletal Muscle Satellite Cell

Science.gov (United States)

2011-01-01

The skeletal muscle satellite cell was first described and named based on its anatomic location between the myofiber plasma and basement membranes. In 1961, two independent studies by Alexander Mauro and Bernard Katz provided the first electron microscopic descriptions of satellite cells in frog and rat muscles. These cells were soon detected in other vertebrates and acquired candidacy as the source of myogenic cells needed for myofiber growth and repair throughout life. Cultures of isolated myofibers and, subsequently, transplantation of single myofibers demonstrated that satellite cells were myogenic progenitors. More recently, satellite cells were redefined as myogenic stem cells given their ability to self-renew in addition to producing differentiated progeny. Identification of distinctively expressed molecular markers, in particular Pax7, has facilitated detection of satellite cells using light microscopy. Notwithstanding the remarkable progress made since the discovery of satellite cells, researchers have looked for alternative cells with myogenic capacity that can potentially be used for whole body cell-based therapy of skeletal muscle. Yet, new studies show that inducible ablation of satellite cells in adult muscle impairs myofiber regeneration. Thus, on the 50th anniversary since its discovery, the satellite cell’s indispensable role in muscle repair has been reaffirmed. PMID:22147605

Integrated centralized utility services to a chemical complex on Jurong Island, Singapore.

Science.gov (United States)

Yan, Y G; Wong, P C Y; Tan, C G; Tang, K F

2003-01-01

SUT pioneered centralized utility services for the chemical industry on Jurong Island, which are cost-effective due to economies of scale, reliable due to inter-connection of satellite operations, and customer tailored for special requirements. The utility services range from the supply of steam and water, wastewater treatment, incineration, terminalling, service corridor to fire fighting. Among the services, water management achieves the complete cycle from wastewater treatment to effluent recycling.

An approach for real-time fast point positioning of the BeiDou Navigation Satellite System using augmentation information

Science.gov (United States)

Tu, Rui; Zhang, Rui; Zhang, Pengfei; Liu, Jinhai; Lu, Xiaochun

2018-07-01

This study proposes an approach to facilitate real-time fast point positioning of the BeiDou Navigation Satellite System (BDS) based on regional augmentation information. We term this as the precise positioning based on augmentation information (BPP) approach. The coordinates of the reference stations were highly constrained to extract the augmentation information, which contained not only the satellite orbit clock error correlated with the satellite running state, but also included the atmosphere error and unmodeled error, which are correlated with the spatial and temporal states. Based on these mixed augmentation corrections, a precise point positioning (PPP) model could be used for the coordinates estimation of the user stations, and the float ambiguity could be easily fixed for the single-difference between satellites. Thus, this technique provided a quick and high-precision positioning service. Three different datasets with small, medium, and large baselines (0.6 km, 30 km and 136 km) were used to validate the feasibility and effectiveness of the proposed BPP method. The validations showed that using the BPP model, 1–2 cm positioning service can be provided in a 100 km wide area after just 2 s of initialization. Thus, as the proposed approach not only capitalized on both PPP and RTK but also provided consistent application, it can be used for area augmentation positioning.

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

Science.gov (United States)

2013-07-01

... of the commercial space sector: the commercial communications satellite industry and the commercial... of the commercial launch sector. It is noted that the Commission has long regulated communication... these views. 42. Anticipating the need for non-Federal spectrum for communications for commercial...

A Case for Data and Service Fusions

Science.gov (United States)

Huang, T.; Boening, C.; Quach, N. T.; Gill, K.; Zlotnicki, V.; Moore, B.; Tsontos, V. M.

2015-12-01

In this distributed, data-intensive era, developing any solution that requires multi-disciplinary data and service requires careful review of interfaces with data and service providers. Information is stored in many different locations and data services are distributed across the Internet. In design and development of mash-up heterogeneous data systems, the challenge is not entirely technological; it is our ability to document the external interface specifications and to create a coherent environment for our users. While is impressive to present a complex web of data, the true measure of our success is in the quality of the data we are serving, the throughput of our creation, and user experience. The presentation presents two current funded NASA projects that require integration of heterogeneous data and service that reside in different locations. The NASA Sea Level Change Portal is designed a "one-stop" source for current sea level change information. Behind this portal is an architecture that integrates data and services from various sources, which includes PI-generated products, satellite products from the DAACs, and metadata from ESDIS Common Metadata Repository (CMR) and other sources, and services reside in the data centers, universities, and ESDIS. The recently funded Distributed Oceanographic Matchup Service (DOMS) project is a project under the NASA Advance Information Technology (AIST) program. DOMS will integrate with satellite products managed by NASA Physical Oceanography Distributed Active Archive Center (PO.DAAC) and three different in-situ projects that are located in difference parts of the U.S. These projects are good examples of delivering content-rich solutions through mash-up of heterogeneous data and systems.

The Matsu Wheel: A Cloud-Based Framework for Efficient Analysis and Reanalysis of Earth Satellite Imagery

Science.gov (United States)

Patterson, Maria T.; Anderson, Nicholas; Bennett, Collin; Bruggemann, Jacob; Grossman, Robert L.; Handy, Matthew; Ly, Vuong; Mandl, Daniel J.; Pederson, Shane; Pivarski, James;

Solar radio proxies for improved satellite orbit prediction

Science.gov (United States)

Yaya, Philippe; Hecker, Louis; Dudok de Wit, Thierry; Fèvre, Clémence Le; Bruinsma, Sean

2017-12-01

Specification and forecasting of solar drivers to thermosphere density models is critical for satellite orbit prediction and debris avoidance. Satellite operators routinely forecast orbits up to 30 days into the future. This requires forecasts of the drivers to these orbit prediction models such as the solar Extreme-UV (EUV) flux and geomagnetic activity. Most density models use the 10.7 cm radio flux (F10.7 index) as a proxy for solar EUV. However, daily measurements at other centimetric wavelengths have also been performed by the Nobeyama Radio Observatory (Japan) since the 1950's, thereby offering prospects for improving orbit modeling. Here we present a pre-operational service at the Collecte Localisation Satellites company that collects these different observations in one single homogeneous dataset and provides a 30 days forecast on a daily basis. Interpolation and preprocessing algorithms were developed to fill in missing data and remove anomalous values. We compared various empirical time series prediction techniques and selected a multi-wavelength non-recursive analogue neural network. The prediction of the 30 cm flux, and to a lesser extent that of the 10.7 cm flux, performs better than NOAA's present prediction of the 10.7 cm flux, especially during periods of high solar activity. In addition, we find that the DTM-2013 density model (Drag Temperature Model) performs better with (past and predicted) values of the 30 cm radio flux than with the 10.7 flux.

Solar radio proxies for improved satellite orbit prediction

Directory of Open Access Journals (Sweden)

Yaya Philippe

2017-01-01

Full Text Available Specification and forecasting of solar drivers to thermosphere density models is critical for satellite orbit prediction and debris avoidance. Satellite operators routinely forecast orbits up to 30 days into the future. This requires forecasts of the drivers to these orbit prediction models such as the solar Extreme-UV (EUV flux and geomagnetic activity. Most density models use the 10.7 cm radio flux (F10.7 index as a proxy for solar EUV. However, daily measurements at other centimetric wavelengths have also been performed by the Nobeyama Radio Observatory (Japan since the 1950's, thereby offering prospects for improving orbit modeling. Here we present a pre-operational service at the Collecte Localisation Satellites company that collects these different observations in one single homogeneous dataset and provides a 30 days forecast on a daily basis. Interpolation and preprocessing algorithms were developed to fill in missing data and remove anomalous values. We compared various empirical time series prediction techniques and selected a multi-wavelength non-recursive analogue neural network. The prediction of the 30 cm flux, and to a lesser extent that of the 10.7 cm flux, performs better than NOAA's present prediction of the 10.7 cm flux, especially during periods of high solar activity. In addition, we find that the DTM-2013 density model (Drag Temperature Model performs better with (past and predicted values of the 30 cm radio flux than with the 10.7 flux.

International Satellite Law

Science.gov (United States)

von der Dunk, Frans

2017-07-01

there are the major categories of space applications—as these have started to impact everyday life on earth: the involvement of satellites in communications infrastructures and services, the most commercialized area of space applications yet; the special issue of space serving to mitigate disasters and their consequences on earth; the use of satellites for remote sensing purposes ranging from weather and climate monitoring to spying; and the use of satellites for positioning, navigation, and timing.

Modern history of meteorological services with pictures for a century

International Nuclear Information System (INIS)

2004-07-01

This book deals with modern history of meteorological services with pictures for a century. It is divided into twelve chapters, which mention meteorological services before the Joseon Dynasty period, meteorological observation about surface weather observation, aero logical observation, meteorological satellite, seismometry, observation on yellow dust, and observation on the falling of thunderbolt, weather forecast, meteorological telecommunication, education for weather, research for weather, promotion on weather, international cooperation, main events, special aid on meteorological services, meteorological disaster and the list of the offices for meteorological services.

GPS Satellite Simulation Facility

Data.gov (United States)

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

DS-CDMA satellite diversity reception for personal satellite communication: Downlink performance analysis

Science.gov (United States)

DeGaudenzi, Riccardo; Giannetti, Filippo

1995-01-01

The downlink of a satellite-mobile personal communication system employing power-controlled Direct Sequence Code Division Multiple Access (DS-CDMA) and exploiting satellite-diversity is analyzed and its performance compared with a more traditional communication system utilizing single satellite reception. The analytical model developed has been thoroughly validated by means of extensive Monte Carlo computer simulations. It is shown how the capacity gain provided by diversity reception shrinks considerably in the presence of increasing traffic or in the case of light shadowing conditions. Moreover, the quantitative results tend to indicate that to combat system capacity reduction due to intra-system interference, no more than two satellites shall be active over the same region. To achieve higher system capacity, differently from terrestrial cellular systems, Multi-User Detection (MUD) techniques are likely to be required in the mobile user terminal, thus considerably increasing its complexity.

Evaluating QoS-enabled information management services in a Navy operational context

Science.gov (United States)

Paulos, Aaron M.; Sinclair, Asher; Loyall, Joseph P.

2011-06-01

Information Management (IM) services support the discovery, brokering, and dissemination of mission-critical information based on the information's content and characteristics. IM services support the dissemination of future information (through subscriptions) and past information (through queries) regardless of its source. To be useful across enterprise and tactical environments, IM services need mission-driven Quality of Service (QoS) features as part of their core functionality. We have developed QoS management features, QoS Enabled Dissemination (QED), that extend an Air Force Research Laboratory (AFRL) developed set of IM services, Phoenix. This paper describes the results of a joint services experiment evaluating QED and Phoenix in a US Navy scenario involving multiple ships connected by a Disconnected, Intermittent, Limited (DIL) satellite network. Experiments evaluate QED and Phoenix's ability to (1) provide IM in the Wide Area Network (WAN) context of the satellite communications, which includes long latencies and background traffic not under QED control; (2) control and utilize active-precedence and queue management features provided by the WAN; (3) handle severe network overload, network disruptions, and dynamic changes in policies; and (4) successfully enforce deadlines and information replacement policies.

Satellite-Based Sunshine Duration for Europe

Directory of Open Access Journals (Sweden)

Bodo Ahrens

2013-06-01

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

Nuovi strumenti di Telerilevamento da satellite per il controllo del territorio

Directory of Open Access Journals (Sweden)

Michele Dussi

2008-03-01

Full Text Available New instruments for land management utilizing satellite remote sensingWe are at the beginning of a new Earth Observation age comprised of large amounts of data, high revisit times as well as high resolution images. All these characteristics were “dream-requirements” for E.O. operators in the past years. Today a new solution dubbed Cosmo-Skymed is being developed which will be operational in the coming months. Cosmo-Skymed is a dual-use end-to-end global data providing system. It makes use of an innovative constellation of 4 sun-synchronous satellites equipped with multimodal high-res synthetic aperture radar (SAR. It operates in X-band and is supported by a wide G/S infrastructure to meet high performance data acquisition and distribution service requirements. It is a made in Italy solution.

Nuovi strumenti di Telerilevamento da satellite per il controllo del territorio

Directory of Open Access Journals (Sweden)

Michele Dussi

2008-03-01

Full Text Available New instruments for land management utilizing satellite remote sensing We are at the beginning of a new Earth Observation age comprised of large amounts of data, high revisit times as well as high resolution images. All these characteristics were “dream-requirements” for E.O. operators in the past years. Today a new solution dubbed Cosmo-Skymed is being developed which will be operational in the coming months. Cosmo-Skymed is a dual-use end-to-end global data providing system. It makes use of an innovative constellation of 4 sun-synchronous satellites equipped with multimodal high-res synthetic aperture radar (SAR. It operates in X-band and is supported by a wide G/S infrastructure to meet high performance data acquisition and distribution service requirements. It is a made in Italy solution.

Encryption protection for communication satellites

Science.gov (United States)

Sood, D. R.; Hoernig, O. W., Jr.

In connection with the growing importance of the commercial communication satellite systems and the introduction of new technological developments, users and operators of these systems become increasingly concerned with aspects of security. The user community is concerned with maintaining confidentiality and integrity of the information being transmitted over the satellite links, while the satellite operators are concerned about the safety of their assets in space. In response to these concerns, the commercial satellite operators are now taking steps to protect the communication information and the satellites. Thus, communication information is being protected by end-to-end encryption of the customer communication traffic. Attention is given to the selection of the NBS DES algorithm, the command protection systems, and the communication protection systems.

Satellite Communications Industry

Science.gov (United States)

1993-04-01

Ariane $loom SAJAC 1 Hughes Satellite Japan 06/94 $150m SAJAC 2 Hughes Satellite Japan -- (spare) $150m SatcomHl GE GE Americom /95 $50m SOLIDARIDAD ...1 Hughes SCT (Mexico) 11/93 Ariane $loom SOLIDARIDAD 2 Hughes SCT (Mexico) /94 $loom Superbird Al Loral Space Com Gp (Jap) 11/92 Ariane $175m

Satellite stories: capturing professional experiences of academic health sciences librarians working in delocalized health sciences programs

Directory of Open Access Journals (Sweden)

Jackie Phinney

2018-01-01

Conclusions: The results from this survey suggest that the role of the academic health sciences librarian at the satellite campus needs to be clearly communicated and defined. This, in turn, will enhance the experience for the librarian and provide better service to the client.

Polar2Grid 2.0: Reprojecting Satellite Data Made Easy

Science.gov (United States)

Hoese, D.; Strabala, K.

2015-12-01

Polar-orbiting multi-band meteorological sensors such as those on the Suomi National Polar-orbiting Partnership (SNPP) satellite pose substantial challenges for taking imagery the last mile to forecast offices, scientific analysis environments, and the general public. To do this quickly and easily, the Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin has created an open-source, modular application system, Polar2Grid. This bundled solution automates tools for converting various satellite products like those from VIIRS and MODIS into a variety of output formats, including GeoTIFFs, AWIPS compatible NetCDF files, and NinJo forecasting workstation compatible TIFF images. In addition to traditional visible and infrared imagery, Polar2Grid includes three perceptual enhancements for the VIIRS Day-Night Band (DNB), as well as providing the capability to create sharpened true color, sharpened false color, and user-defined RGB images. Polar2Grid performs conversions and projections in seconds on large swaths of data. Polar2Grid is currently providing VIIRS imagery over the Continental United States, as well as Alaska and Hawaii, from various Direct-Broadcast antennas to operational forecasters at the NOAA National Weather Service (NWS) offices in their AWIPS terminals, within minutes of an overpass of the Suomi NPP satellite. Three years after Polar2Grid development started, the Polar2Grid team is now releasing version 2.0 of the software; supporting more sensors, generating more products, and providing all of its features in an easy to use command line interface.

Solar Power Satellites

CERN Document Server

Flournoy, Don M

2012-01-01

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

Geostationary satellites collocation

CERN Document Server

Li, Hengnian

2014-01-01

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

An assessment of the status and trends in satellite communications 1986-2000: An information document prepared for the Communications Subcommittee of the Space Applications Advisory Committee

Science.gov (United States)

Poley, W. A.; Stevens, G. H.; Stevenson, S. M.; Lekan, J.; Arth, C. H.; Hollansworth, J. E.; Miller, E. F.

1986-01-01

This is a response to a Space Applications Advisory Committee (SAAC) request for information about the status and trends in satellite communications, to be used to support efforts to conceive and recommend long range goals for NASA communications activities. Included in this document are assessments of: (1) the outlook for satellite communications, including current applications, potential future applications, and impact of the changing environment such as optical fiber networks, the Integrated Services Digital Network (ISDN) standard, and the rapidly growing market for Very Small Aperture Terminals (VSAT); (2) the restrictions imposed by our limited spectrum resource; and (3) technology needs indicated by future trends. Potential future systems discussed include: large powerful satellites for providing personal communications; VSAT compatible satellites with onboard switching and having voice capability; large satellites which offer a pervasive T1 network service (primarily for video-phone); and large geostationary communications facilities which support common use by several carriers. Also, discussion is included of NASA particular needs and possible future systems. Based on the mentioned system concepts, specific technology recommendations are provided for the time frames of now - 1993, 1994 - 2000, and 2000 - 2010.

Muscle satellite cell heterogeneity and self-renewal

Science.gov (United States)

Motohashi, Norio; Asakura, Atsushi

2014-01-01

Adult skeletal muscle possesses extraordinary regeneration capacities. After muscle injury or exercise, large numbers of newly formed muscle fibers are generated within a week as a result of expansion and differentiation of a self-renewing pool of muscle stem cells termed muscle satellite cells. Normally, satellite cells are mitotically quiescent and reside beneath the basal lamina of muscle fibers. Upon regeneration, satellite cells are activated, and give rise to daughter myogenic precursor cells. After several rounds of proliferation, these myogenic precursor cells contribute to the formation of new muscle fibers. During cell division, a minor population of myogenic precursor cells returns to quiescent satellite cells as a self-renewal process. Currently, accumulating evidence has revealed the essential roles of satellite cells in muscle regeneration and the regulatory mechanisms, while it still remains to be elucidated how satellite cell self-renewal is molecularly regulated and how satellite cells are important in aging and diseased muscle. The number of satellite cells is decreased due to the changing niche during ageing, resulting in attenuation of muscle regeneration capacity. Additionally, in Duchenne muscular dystrophy (DMD) patients, the loss of satellite cell regenerative capacity and decreased satellite cell number due to continuous needs for satellite cells lead to progressive muscle weakness with chronic degeneration. Thus, it is necessary to replenish muscle satellite cells continuously. This review outlines recent findings regarding satellite cell heterogeneity, asymmetric division and molecular mechanisms in satellite cell self-renewal which is crucial for maintenance of satellite cells as a muscle stem cell pool throughout life. In addition, we discuss roles in the stem cell niche for satellite cell maintenance, as well as related cell therapies for approaching treatment of DMD. PMID:25364710

Muscle Satellite Cell Heterogeneity and Self-Renewal

Directory of Open Access Journals (Sweden)

Norio eMotohashi

2014-01-01

Full Text Available Adult skeletal muscle possesses extraordinary regeneration capacities. After muscle injury or exercise, large numbers of newly formed muscle fibers are generated within a week as a result of expansion and differentiation of a self-renewing pool of muscle stem cells termed muscle satellite cells. Normally, satellite cells are mitotically quiescent and reside beneath the basal lamina of muscle fibers. Upon regeneration, satellite cells are activated, and give rise to daughter myogenic precursor cells. After several rounds of proliferation, these myogenic precursor cells contribute to the formation of new muscle fibers. During cell division, a minor population of myogenic precursor cells returns to quiescent satellite cells as a self-renewal process. Currently, accumulating evidence has revealed the essential roles of satellite cells in muscle regeneration and the regulatory mechanisms, while it still remains to be elucidated how satellite cell self-renewal is molecularly regulated and how satellite cells are important in aging and diseased muscle. The number of satellite cells is decreased due to the changing niche during ageing, resulting in attenuation of muscle regeneration capacity. Additionally, in Duchenne muscular dystrophy (DMD patients, the loss of satellite cell regenerative capacity and decreased satellite cell number due to continuous needs for satellite cells lead to progressive muscle weakness with chronic degeneration. Thus, it is necessary to replenish muscle satellite cells continuously. This review outlines recent findings regarding satellite cell heterogeneity, asymmetric division and molecular mechanisms in satellite cell self-renewal which is crucial for maintenance of satellite cells as a muscle stem cell pool throughout life. In addition, we discuss roles in the stem cell niche for satellite cell maintenance, as well as related cell therapies for approaching treatment of DMD.

Satellite communications network design and analysis

CERN Document Server

Jo, Kenneth Y

2011-01-01