Essential Information & explanations, latest texts & monographs on
Communications_satellite.
GPS for Mariners by Robert J. Sweet
Integrating GIS and the Global Positioning System by Karen Steede-Terry
Satellite Communications by Dennis Roddy
Satellite Communications Systems: Systems, Techniques and Technology by Gérard Maral
Signal Theory Methods in Multispectral Remote Sensing by David A Landgrebe
GSM Switching, Services, and Protocols by Joerg Eberspaecher
Something New Under the Sun: Satellites and the Beginning of the Space Age by Helen Gavaghan
Satellite-Based Cellular Communications by Bruno Pattan
Communication Satellites in the Geostationary Orbit by Donald Jansky
The Future Air Navigation System (Fans): Communications Navigation Surveillance Air Traffic Management by Vincent P. Galotti
Introduction to Satellite Communication (Artech House Space Applications Series) by Bruce R. Elbert
Satellite Communications by Timothy Pratt
Digital Communications Systems: With Satellites and Fiber Optics Applications by Harold Kolimbiris
The Global Positioning System & Inertial Navigation by Jay A. Farrell
Cable and Satellite Television Industries, The: (Part of the Allyn & Bacon Series in Mass Communication) by Patrick R. Parsons
Communications satellite
A communications satellite (sometimes abbreviated to comsat) is an artificial satellite stationed in space for the purposes of telecommunications using radio at microwave frequencies. Most communications satellites use geosynchronous orbits or near-geostationary orbits, although some recent systems use low Earth-orbiting satellites.
Communications satellites provide a technology that is complementary to that of fiber optic submarine communication cables.
The concept of the communications satellite was first proposed by Arthur C. Clarke, based on Herman Potočnik's pseudonymous work from 1929. In 1945 Clarke published an article titled "Extra-terrestrial Relays" in the magazine Wireless World. The article described the fundamentals behind the deployment artificial satellites in geostationary orbits for the purpose of relaying radio signals. Thus Arthur C. Clarke is often quoted as the inventor of the communcations satellite.
Telstar was the first active communications satellite. Belonging to AT&T as part of a a multi-national agreements between AT&T, Bell Telephone Laboratories, NASA, the British General Post Office, and the French National PTT (Post Office.) to develop satellite communication. It was launched by NASA from Cape Canaveral on July 10, 1962, the first privately sponsored space launch. Telstar was placed in an elliptical orbit (completed once every 2 hours and 37 minutes), rotating at a 45 degree angle above the equator.
The first geosynchronous communications satellite was Syncom 2, launched on July 26, 1963. However, Syncom 2 was positioned in an inclined orbit so special tracking equipment was needed to see it. The first geosynchronous communications satellite that could be seen from a fixed satellite antenna (over North America) was Anik 1, a Canadian
satellite launched in 1973.
A low Earth orbiting satellite is a satellite with a low orbit with an orbital period much shorter than a day. As these satellites can only be seen from any given part of the Earth for a short time as they pass over, large numbers of these satellites are needed to ensure continuous coverage. A group of satellites working in concert thus is known as a satellite constellation. It is possible to offer discontinous coverage using a low Earth orbit satellite capable of storing data received while passing over one part of Earth and transmitting it later while passing over another part. This will be the case with the CASCADE system of Canada's CASSIOPE communications satellite.
A direct broadcast satellite is a special high-powered communications satellite that transmits to small DBS satellite dishes. Direct broadcast satellites always operate in the upper portion of the Ku band.
Examples of satellite constellations are the GPS and the Iridium and Globalstar satellite telephony services.
See also
External links
The above article is adapted from from Wikipedia All Wikipedia article text is available under the terms of the GNU Free Documentation License
Updates and comments at Essential Facts blog
World Class Photographers
Some philosophical movements
|
|
Interesting Links
Latest Dowloadable
Communications_satellite PDF s & Ebooks
Top PDF and eBook Downloads
Bibliographic Resources
Dates
20-th Century
20-th Century Details
Chromosomes and Genomics
Sports
Kitchen Knowledge
Hollywood Icons
Classical Music
Music Directory.
Music: Jazz
Music: Rock
Music: Country
Music: Popular A-E
Music: Popular F-L
Music: Popular M-S
Music: Popular T-Z
Mythology
Philosophy
Politics
Retirement
Agriculture
Agriculture: Flowers
Agriculture: Gardening
Biology
Biology & Biologists
Cell Science
Cell Science: Cells
Cell Science: Stem Cells
California
Cats & Dogs
Ethics
Electronics
Logic
The Greats
Architectural Dates & Places
Styles ABC
Styles DTOI
Styles JTON
Styles OTOZ
Buddhism
Marketing
Psychology
Enginering Systems 1
Mathematics
Classic Authors
Fear No Exams
Characters & countries
Law & Legal Topics
Linguistics
Movies
Most successful Movies
Science Plus
Science & Computers
Quantum Theory
|