Elliptical orbit satellite, system, and deployment with controllable coverage characteristics
AssigneeMobile Communications Holdings, Inc.
InventorsDavid Castiel, John E. Draim, Jay Brosius
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Abstract
A special set of elliptical satellite orbits are described which allow preferential coverage of one parameter over another. According to a first modification, the orbits are retrograde, and preferentially cover one geographical location or time of day as compared with another. A second modification uses prograde orbits and allows the apogee of the orbit to be offset a constant amount with respect to the sun, to thereby cover a different time of day relative to the others. According to a special preferred mode of the invention, the apogee is always pointing towards the sun.
Claims30
A communication system, comprising:
- a constellation of satellites in orbit around the earth, each defining an elliptical orbit which has orbital parameters to satisfy the equation ##EQU10## , where .OMEGA. is the right ascension of an ascending node, and .omega. is an argument of perigee, and wherein each of said satellites in orbit asymmetrically covers one parameter of coverage more than another in a way which is constant at all positions of the earth relative to the sun, and
- a plurality of earth stations, each positioned on the earth, each including tracking equipment to track a motion of at least one of said satellites, and communication equipment to communicate with said at least one of said satellites.
A method of communicating with a satellite, comprising the steps of:
- propelling said satellite into an elliptical orbit which has orbital parameters to satisfy the equation ##EQU11## , where .OMEGA. is the right ascension of an ascending node, and .omega. is an argument of perigee, and wherein said orbit has characteristics to asymmetrically cover one parameter of coverage more than another in a way which is constant relative to a position of the sun, all year round;
- providing a ground station which tracks a position in the orbit where the satellite will be at any given time;
- and
- communicating between the ground station and the satellite.
Dependencies are inferred from the claim text.