Research on GPS Receiver Autonomous Integrity Monitoring Algorithm In the Occurrence of Two-satellite Faults

Er Shen Wang,Xiao Dong Yue,Tao Pang,Zhi Xian Zhang,W.-P Sung,J.C.M Kao

doi:10.1051/matecconf/20164401017

Abstract

Reliability is an essential factor for GPS navigation system. Therefore, an integrity monitoring is considered as one of the most important parts for a navigation system. GPS receiver autonomous integrity monitoring (RAIM) technique can detect and isolate fault satellite. Based on particle filter, a novel RAIM method was proposed to detect two-satellite faults of the GPS signal by using hierarchical particle filter. It can deal with any system nonlinear and any noise distributions. Because GNSS measurement noise does not follow the Gaussian distribution perfectly, the particle filter can estimate the posterior distribution more accurately. In order to detect fault, the consistency test statistics is established through cumulative log-likelihood ratio (LLR) between the main and auxiliary particle filters (PFs).Specifically, an approach combining PF with the hierarchical filter is used in the process of two-satellite faults. Through GPS real measurement, the performance of the proposed GPS two-satellite faults detection algorithm was illustrated. Some simulation results are given to evaluate integrity monitoring performance of the algorithm. Validated by the real measurement data, the results show that the proposed algorithm can successfully detect and isolate the faulty satellite in the case of non-Gaussian measurement noise.

Highlights

Based on the particle filter, the two-satellite faults detection and isolation algorithm was designed
The general scheme of the approach followed by a hierarchical particle filtering based log likelihood ratio (LLR) approach to fault detection and isolation (FDI) are presented
The experimental raw measurement data are collected by Global positioning system (GPS) receiver N220 (positioning accuracy is 2.5 meters (RMS)), the measurement data including the position information of satellites and the pseudoranges were generated for each epoch for 418 epochs

Summary

Introduction

Based on the particle filter, the two-satellite faults detection and isolation algorithm was designed. The new integrity monitoring algorithm for RAIM using hierarchical particle filter was proposed. The proposed algorithm estimates a distribution of a measurement residual from the posterior density and detects large residuals to satisfy a false alarm rate. With a nonGaussian measurement error, the algorithm can estimate the distribution of the state more accurately. The work focused on the effect of a non-Gaussian error distribution of the GPS measurement on the integrity monitoring. The general scheme of the approach followed by a hierarchical particle filtering based log likelihood ratio (LLR) approach to fault detection and isolation (FDI) are presented. The GPS receiver autonomous integrity monitoring and its usefulness are presented with numerical simulation and experiment

Methods

Results

Conclusion