US 6,150,977 A · Method for enhancing the performance of a satellite communications system using multibeam antennas

Abstract

The present invention provides a method for determining antenna pointing error of a satellite antenna (702-716) that produces at least one spot beam having a corresponding gain pattern. The method obtains from a first unique location (510) on the ground a first measurement of a spot beam strength for a first cell (502). Similar measurements are obtained at second and third unique locations (512, 514). Attitude component errors, for example the roll or pitch attitude component errors may then be determined. The method may further determine a yaw attitude component error based on fourth, fifth, and sixth measurements of spot beam strength made from unique locations (616-620) in a second cell (604) also generated by the antenna. Additional measurements may be collected in each beam at unique locations (510-514, 516-520, 610-614, 616-620) and averaged to reduce the temporary or zero means effects of rain, scintillation, or other atmospheric conditions on the spot beam strength. Furthermore, the method may transmit any of the measurements to a central processor (422) which determines the attitude component errors based on the measurements.

Claims20

Dependent claims

A method for determining antenna pointing error of a satellite antenna that produces a plurality of spot beams in a substantially fixed location, said spot beams having corresponding gain patterns, the method comprising the steps of:

obtaining at a first unique location on the ground a first measurement corresponding to spot beam strength of a first spot beam for a first cell, said first spot beam located at a first substantially fixed location;
obtaining at a second unique location on the ground a second measurement corresponding to spot beam strength for said first spot beam for said first cell;
obtaining at a third unique location on the ground a third measurement corresponding to spot beam strength for said first spot beam for said first cell;
and
determining at least one attitude component error based on said first, second, and third measurements and based on a downlink gain pattern for said first spot beam.

2 more elements

A method for determining satellite pointing error of a satellite that produces a plurality of spot beams in substantially fixed locations, said spot beams having corresponding gain patterns, the method comprising the steps of:

establishing at least first, second, and third measurement ground stations in unique locations near an expected periphery of a first cell;
obtaining a first measurement corresponding to a spot beam strength of a first spot beam for said first cell at said first ground station, said spot beam located at a first substantially fixed location;
obtaining a second measurement corresponding to said spot beam strength of said first spot beam for said first cell at said second ground station;
obtaining a third measurement corresponding to said spot beam strength of said first spot beam for said first cell at said third ground station;
determining at least one attitude component error based on said first, second, and third measurements and on a downlink gain pattern of said first spot beam.

2 more elements

Dependencies are inferred from the claim text.

Method for enhancing the performance of a satellite communications system using multibeam antennas

Life of this patent

Method for enhancing the performance of a satellite communications system using multibeam antennas

Life of this patent

Abstract

Claims20