Multipath Interference Order Selection and Mitigation in GPS-Based Attitude Determination Systems

摘要

Attitude determination systems based on GPS are known to be highly vulnerable to carrier-phase multipath interference. In the work described here, multipath interference is related to the joint geometry of the satellite, the attitude determination system, and the scatterers surrounding the receiver antenna array. A highly effective algorithm for multipath reduction is obtained, with no assumptions made about the multipath interference order. The proposed algorithm is performed iteratively over each data block. It is simple to implement and especially suitable for static and perhaps slowly varying environments. Combining the geometrical structure with the multipath interference model leads to an estimate of the number of reflectors. The model order is determined when a formulated stopping criterion for the iterative process is fulfilled. The projected distance to each reflector is obtained analytically. Demonstration based on field-measured data showed a substantial multipath reduction capability.