基于卫星服务中断的GPS在中国服务区可用性分析

Analysis of Availability of GPS in China Territory Volume Based on Satellite Service Intermittence

由于导航卫星硬件失效和轨道维持等原因,会引起卫星服务的暂时中断。卫星服务中断又会导致导航星座可用性下降。以GPS卫星4类中断的平均间隔时间、平均恢复时间为参数,建立了导航卫星的平均可用性及导航星座平均可用性数学模型。仿真分析了卫星服务中断的情况下GPS在我国服务区的可用性。仿真结果对于我国目前进行的区域卫星导航系统建设(北斗卫星导航系统建设的第2步)以及参与GPS市场竞争均具有重要作用。

Due to hard failures and satellite orbit maintenance,etc,satellite service intermittence happens,which reduces the availability of navigation constellation.The availability model of satellite and constellation was set up based on the Means Time Between Failures（MTBF） and the Mean Time To Repair（MTTR）,which was able to evaluate objectively navigation constellation performance.The number of the visible satellites and the PDOP（Position Dilution of Precision） availability of GPS were discussed and calculated in detail in China terrestrial service volume based on four types satellite＇s intermittence. The simulation result was very useful for COMPASS eonstruetion nowadays and for China GPS user.