| 摘要 |
PROBLEM TO BE SOLVED: To provide a passive position determining method using two low-altitude earth orbiting satellites. SOLUTION: A user terminal, at least two satellites having known positions and velocities, and a gateway (i.e., ground base station) communicating with the user terminal via the satellites are included. The method includes the step of determining a range difference parameter and a range rate difference parameter. The range difference parameter represents the difference between (1) the distance between the first one of the satellites and the user terminal and (2) the distance between the second one of the satellites and the user terminal. The range rate difference parameter represents the difference between (a) the relative radial velocity between the first one of the satellites and the user terminal and (b) the relative radial velocity between the second one of the satellites and the user terminal. The position of the user terminal on the earth surface is determined based on the known positions and velocities of the satellites, the range difference parameter, and the range rate difference parameter. COPYRIGHT: (C)2008,JPO&INPIT
|
