| 摘要 |
An apparatus, method, and process for quickly and accurately determining the position of a user terminal (124,126) in a satellite communications system (100). An initial coarse estimate of the radius of the Earth at a terminal position is made (302,402). The geometry of satellites being used (116,118) and the user terminal (124,126) is then determined. Two satellites are used, the satellite-user terminal geometry includes the range (406,408) of each satellite (116,118) with respect to the user terminal (124,126). An initial position estimate is determined based on the radius and the satellite-user terminal geometry. The coarse radius estimate (304,404) can then be formed into a fine estimate (310,412) and the initial position estimate further refined. |
