A Robust Vector Tracking Loop Based Federated Filter

摘要

Vector Tracking Loop (VTL) is a recently developed method forenhancing Global Positioning System (GPS) receiver signal trackingcapacity and performance. Compared with conventional Scalar TrackingLoop (STL), VTL operates with combining all tracking channel togetherinto a center navigation filter, and mutual aiding between channels aregained. However, in this architecture, the abnormity of certain channels willmake great impact on the center navigation filter, and even possibly leadingto receiver’s loss of lock of all channels. Motivated by this problem, in thispaper, a robust VTL is proposed and evaluated. In this new architecture, asub-filter is designed for each channel, after which is a running statemonitoring function built using sub-filter information. Thereby, eachchannel’s fault can be detected by the running state function, which cangrantee the stability of the receiver. A semi-physical simulation isimplemented based on an open source software-defined receiver. The testresults show that the proposed new VTL can effectively improve therobustness and position accuracy compared with conventional VTL undersome presence of fault channels.