A Study on GDOP for Vector-Based Tracking Loop GPS/INS Receiver

Abstract

Geometric Dilution of Precision (GDOP) value will become larger when the number of visible satellites is less than four or the geometry of satellite constellation is poor, a GDOP Chimney Peak phenomenon is also easy to emerge [, the positioning accuracy of GPS receiver will be affected seriously. A vector-based tracking loop GPS/INS receiver design method is proposed in this paper. The current position of receiver is given by INS, Line-of-Sight (LOS) unit vectors between receiver and satellites will be built, which are transmitted into vector tracking loop, the relationship between LOS and GDOP is introduced in detail. Pseudorange and pseudorange-rate are used as measurements to design navigation filter. The simulation results demonstrate that proposed vector tracking method can avoid GDOP Chimney Peak phenomenon, position Root Mean Square error is less than 10 meters.