三频GNSS接收机的RAIM算法研究

摘要

新一代全球导航卫星系统(GNSS)将为民用用户提供多个可用频点.为了使接收机能够充分利用多频点的卫星信号,提高系统的完好性,提出了一种能够用于三频GNSS接收机的接收机自主完好性监测(RAIM)算法.该算法通过建立三频线性化测量方程,将各频点的伪距信息融合起来.对三频伪距测量误差进行预白化处理,从而可以沿用奇偶矢量法的基本原理进行故障检测和隔离.经过详细理论推导,得到了三频RAIM算法中奇偶矩阵与单频奇偶矩阵间的简单转换关系,极大程度地降低了故障检测和隔离的计算复杂度,更易于在GNSS接收机中实现.仿真结果表明,三频RAIM算法可以提高传统单频RAIM算法的故障检测率和隔离率,尤其在伪距偏差较小的时候,性能改善更为显著.%In order to make full use of the multi-frequency signal in the future Global Navigation Satellite System (GNSS) and improve the system integrity, a new Receiver Autonomous Integrity Monitoring ( RAIM) algorithm for triple-frequency GNSS receivers is proposed. In this algorithm, a triple-frequency linearized measurement equation is built and should be pre-whitened, so that the parity vector method can be adopted for fault detection and isolation. The parity matrix for triple-frequency RAIM algorithm can be obtained by simple transform of the original single-frequency parity matrix through detailed theoretical derivation, thus significantly reducing the computational burden of GNSS receivers. Simulation results show that the triple-frequency RAIM algorithm can increase the fault detection and isolation rate compared with the single-frequency algorithm, and the performance improvement is more significant when the pseudo range bias is small.