초록 ▼

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

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. A position call prompts a gateway to establish a traffic channel on which a positioning message 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. 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.

대표청구항 ▼

1. A method for determining the position of a user terminal in a satellite communications system, comprising the steps of:repetitively measuring the characteristics of communication signals exchanged between said user terminal and a gateway through one or more satellites, wherein all of the repetiti

1. A method for determining the position of a user terminal in a satellite communications system, comprising the steps of:repetitively measuring the characteristics of communication signals exchanged between said user terminal and a gateway through one or more satellites, wherein all of the repetitive measurements are accumulated; and combining the accumulated measurements to produce a position estimate, thereby mitigating the effects of random errors in the measurements.