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US 5,717,404 AGranted
Satellite ephemeris determination system using GPS tracking techniques
AssigneeHughes Electronics Corporation
InventorRajendra P. Malla
Life of this patent
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AssigneeHughes Electronics Corporation
InventorRajendra P. Malla
Estimating the term…
A system (10) for providing ephemeris data of a medium to high orbit satellite (12) relative to the Earth (30), where the satellite (12) is in an orbit substantially greater than 20,000 kilometers. The inventive system (10) includes plural transmitters (14, 16, 18, 20, 22, and 24) located within 20,000 kilometers of the Earth for transmitting information relating to the ephemeris of each transmitter relative to the Earth and time. This information is received and processed onboard the satellite (12) to provide ephemeris data. In a specific implementation, the transmitters (14, 16, 18, 20, 22, and 24) are GPS transmitters. One or more of the transmitters may be a ground or air based pseudolite. The transmitters have a geometric dilution of precision of six or less. Each pseuodlite transmitter includes a power supply sufficient to ensure that the signal received by the medium to high orbit satellite is of sufficient signal strength (e.g., -170 dBw to -160 dBw). Using one or more GPS pseuodlites and one or more GPS satellite transmitters, the ephemeris of a high or medium orbit satellite may be fixed precisely, inexpensively, in real time in an autonomous manner.
A system for providing ephemeris data of a second object relative to a first object, said first object and said second object being separated by a distance substantially greater than 20,000 kilometers said system comprising:
A system for providing ephemeris data of a satellite disposed in an orbit above the Earth greater than 20,000 kilometers, said system comprising:
A method for providing ephemeris data of a second object relative to a first object, said first object and said second object being separated by a distance substantially greater than 20,000 kilometers, said method comprising the steps of:
Dependencies are inferred from the claim text.