A SYSTEM USING LEO SATELLITES FOR CENTIMETER-LEVEL NAVIGATION

摘要

Disclosed herein is a system for rapidly resolving position with centimeter-level accuracy for a mobile or stationary receiver (4). This is achieved by estimating a set of parameters that are related to the integer cycle ambiguities which arise in tracking the carrier phase of satellite downlinks (5, 6). In the preferred embodiment, the technique involves a navigation receiver (4) simultaneously tracking transmissions (6) from Low Earth Orbit Satellites (LEOS) (2) together with transmissions (5) from GPS navigation satellites (1). The rapid change in the line-of-sight vectors from the receiver (4) to the LEO signal sources (2), due to the orbital motion of the LEOS, enables the resolution with integrity of the integer cycle ambiguities of the GPS signals (5) as well as parameters related to the integer cycle ambiguity on the LEOS signals (6). These parameters, once identified, enable real-time centimeter-level positioning of the receiver (4).