| 摘要 |
A system and method for resolving ambiguity in an ambiguous position solution for a user terminal position in a satellite communications system which includes a user terminal (106), at least one satellite (104), and a gateway (102) communicating with the user terminal (106) through the satellite (104). Each satellite (104) has a plurality of satellite beams (601-616) which each illuminate a region on the Earth in a known pattern relative to a satellite sub-track (404). A satellite beam (601-616) illuminating the user terminal (106) is identified along with its corresponding position relative to the subtrack (404). The orientations of possible user terminal positions (408A, 408B) and the identified beam (601-616) relative to the satellite sub-track (404) are compared to each other. Possible user terminal positions (408A, 408B) falling on an incorrect side of the sub-track (404) from the detected beam (601-616) illuminating the user terminal (106), are considered as incorrect solutions for that user terminal (106). The ambiguity solution can be determined using satellite identification and comparison elements in the user terminal (106), or at the gateway (102), in which case certain beam information is reported to the gateway (102). In further aspects of the invention, the beam being identified can be either a forward link (601-616) or reverse link (621-636) beam, or both, and each link has a different beam pattern.
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