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This table contains examples of downlink frequency assignments; Satellite Frequency Band Terra: 8212.5 MHz: 8175-8215 MHz METEOROLOGICAL-SATELLITE SERVICE Earth exploration-satellite service Aqua: 8160 MHz: 8025-8175 MHz: Earth exploration-satellite service NOAA 17,18 1707 MHz 1700-1710 MHz: Meteorological-satellite service: ERS-2 (High rate ...
A radio link from an earth station at a given location to a space station, or vice versa, conveying information for a space radiocommunication service other than for the fixed-satellite service. The given location may be at a specified fixed point, or at any fixed point within specified areas.
The frequency differences observed are due to different Doppler shift resulting from relative satellite motion and differences in the translation frequencies of the two satellite channels. Channel translation frequencies and downlink Doppler shift and delay can be calibrated out of the measurements by observing transmitters of known location ...
Due to the high orbital speed of the amateur satellites, the uplink and downlink frequencies will vary during the course of a satellite pass. This phenomenon is known as the Doppler effect . While the satellite is moving towards the ground station, the downlink frequency will appear to be higher than normal.
A communications satellite's transponder is the series of interconnected units that form a communications channel between the receiving and the transmitting antennas. [1] It is mainly used in satellite communication to transfer the received signals. A transponder is typically composed of: an input band-limiting device (an input band-pass filter),
Fox-1B, AO-91 or AMSAT OSCAR 91 [3] is a United States amateur radio satellite. It is a 1U Cubesat, was built by the AMSAT-NA and carries a single-channel transponder for FM radio. The satellite has a whip antenna for the 70 cm and 23 cm bands (uplink), and a second antenna for the 2 m band (downlink).
For certain phase modulation (PM) downlinks, the uplink to downlink frequency ratio was exactly 221/240, with a coherent transponders used. A phase locked loop on the spacecraft multiplied the uplink carrier frequency by 240/221 to produce the downlink carrier frequency. A local oscillator produced the downlink carrier if the uplink was not ...
The first satellite of the Molniya series was launched on 23 April 1965 and was used for experimental transmission of TV signals from a Moscow uplink station to downlink stations located in Siberia and the Russian Far East, in Norilsk, Khabarovsk, Magadan and Vladivostok.