基于多假设解分离的CRAIM算法研究

Research on CRAIM Algorithm Based on Multiple Hypothesis Separation Solution

为满足Ⅲ类精密进近和舰载机着舰等高精度定位的完好性需求,提出了一种基于多假设解分离(MHSS)的CRAIM算法。在约束条件下对各故障假设模式的完好性风险和连续性风险进行优化分配,计算最优垂直保护门限(VPL),并分析了VPL和单颗卫星故障先验概率、单差载波相位测量偏差最大值及标称值之间的关系。实验结果表明,该算法降低了VPL值,提高了系统可用性,并且卫星故障先验概率、偏差最大值及标称值会影响VPL的大小,但不影响算法的稳定性。

In order to meet the integrity requirement of high accuracy positioning like precision approach CAT Ⅲ and carrier-based aircraft landing, a MHSS (Multiple Hypothesis Separation Solution) based CRAIM algorithm is proposed in this paper. The integrity risk and continuity risk of each failure mode are optimized under the constraint condition to calculate the optimal vertical protection level ( VPL ) threshold, and the relationships between VPL and priori probability of single satellite fault, maximum and nominal value of single-difference carrier phase measurement deviation are analyzed. The simulation results show that the proposed algorithm can provide a lower VPL and increase the availability of the system, VPL will be affected by the priori probability of satellite fault, maximum and nominal value of measurement deviation while the algorithm performance is relatively stable.