| 摘要 |
An improved method for determining the location of a user terminal with a high degree of accuracy. By repeating N times the basic active positioning measurement sets, a much better accuracy is reached that will be of value to the user. According to the method of the present invention, the user makes a position call (404). A position call prompts a gateway to establish a traffic channel (406) on which a positioning message (408) will yield the basic set of measurements: round-trip delay and round-trip Doppler in single-satellite positioning, and the addition of delay-difference and Doppler difference to a second satellite in two-satellite positioning. The accumulated measurements are used to determine position and theoretical error (410, 412). The call is terminated when an accuracy threshold is reached or a time limit has expired. The user terminal receives a position message or a failure message (416).
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