IOWAS算法的卫星分组策略研究

摘要

探讨了IOWAS算法中的卫星分组策略优化问题.通过分析各种精度因子参数之间的关系,并借鉴已有的针对GDOP最小时卫星最佳分布的研究成果,给出了优化的卫星分组策略:使每个分组内的卫星分布都尽量与最佳分布相似,从而使每个分组都获得尽量小的VDOP值.仿真结果表明,分组策略的优化可以进一步提高IOWAS算法的可用性,尤其是在垂向告警线比较小的时候,性能改善更为显著.%The satellite grouping strategy for IOWAS algorithm is discussed. By analyzing the relationship between different DOP parameters and using the existing results of the optimal satellite geometries which can obtain the smallest GDOP values, we propose an optimized satellite grouping strategy. The main idea is to make the satellite geometries for each group most similar to the optimal geometries which can obtain the VDOP values as small as possible. Simulation results show that the optimized satellite grouping strategy can further increase the availability of IOWAS algorithm and the improvement is more significant when the vertical protection level is small.