接收机自主完好性监测(receiverautonomousintegritymonitoring,RAIM)算法因具备独立自主、快速告警等优点被广泛应用于航空领域。由于传统RAIM算法仅在故障星出现粗大伪距偏差时才具备较高的检测与识别率,因此难以满足高精密航空飞行安全需求。为了提升完好性水平,从改善卫星空间构型与提升测距精度出发,提出一种组合星座双频RAIM算法。该算法建立了北斗/GPS双频伪距观测模型,在考虑同颗卫星双频信号伪距观测噪声相关性与伪距偏差在不同频点间扩散现象的条件下,继承奇偶矢量方法实现了故障检测与识别,提高了算法对于小伪距偏差的敏感度,图形与数据化仿真结果证明了该算法的有效性与可行性。

RAIM algorithm which has the advantages of independence and quick alarm is widely used in aviation. Since traditional RAIM algorithm has high detection and recognition rate only when fault satellite appears bulky pseudorange deviation, it is difficult to meet the demand of high precision flight safety. In order to improve the integrity, through improving satellite space configuration and the precision of distance measurement, a combination constellation double-frequency RAIM algorithm put forward. It has established the BDS/GPS dualfrequency pseudorange observation model, considering satellite dual-frequency signal pseudorange observation noise correlation and deviation between different frequency point diffusion phenomenon, to inherit the parity vector method for fault detection and recognition, the sensitivity of the algorithm for small pseudorange deviation. The graphic and numeral simulation results demonstrate that the method is effective and feasible.