Satellite ephemeris determination system using GPS tracking techniques
First Claim
1. 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:
- transmitter means including plural transmitters located within 20,000 kilometers of the first object for transmitting information relating to the ephemeris thereof relative to the first object and time;
receiver means located on the second object for receiving said information; and
processing means located on the second object for processing the information and providing signals relating to the ephemeris of said second object.
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Accused Products
Abstract
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.
38 Citations
20 Claims
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1. 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:
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transmitter means including plural transmitters located within 20,000 kilometers of the first object for transmitting information relating to the ephemeris thereof relative to the first object and time; receiver means located on the second object for receiving said information; and processing means located on the second object for processing the information and providing signals relating to the ephemeris of said second object. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A system for providing ephemeris data of a satellite disposed in an orbit above the Earth greater than 20,000 kilometers, said system comprising:
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transmitter means including plural Global Positioning System transmitters for transmitting information relating to the ephemeris thereof relative to the Earth and time, said transmitters being located within 20,000 kilometers of the Earth and having a geometric dilution of precision less than or equal to six; receiver means located on the satellite for receiving said information; and processing means located on the satellite for processing the information and providing signals relating to the ephemeris of said satellite. - View Dependent Claims (17, 18, 19)
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20. 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:
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transmitting information relating to the ephemeris of plural transmitters located within 20,000 kilometers of the first object relative to the first object and time; receiving said information with a receiver at said second object; and processing the information at said second object and providing signals relating to the ephemeris of said second object.
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Specification