Real-time detection and elimination method for BDS signal-in-space anomalies

Abstract

The BeiDou navigation satellite system (BDS) signal-in-space anomaly is an important factor affecting the signal-in-space quality assessment. Detecting and excluding signal-in-space anomalies is not only a method for constructing a BDS signal-in-space fault model but can also help ensure the BDS navigation and positioning integrity. Traditional methods, based on post precision ephemeris and broadcast ephemeris, maintain some disadvantages, such as a large delay and a low sampling rate. In this paper, a carrier-phase smoothing pseudorange algorithm based on Kalman filtering is proposed, and a real-time estimation method of a BDS signal-in-space user range error is established to detect and eliminate signal-in-space anomalies in real time, based on the statistical characteristics of signal-in-space user range error. The experimental results, based on 1 Hz data of the international GNSS service (IGS) ground observation network, show that the proposed method has an estimation accuracy of 1.15 m for a BDS signal-in-space user range error, which can effectively identify signal-in-space anomalies caused by satellite orbit and clock faults.