异轨三星时差定位精度分析

Study on different orbit three satellites geolocation accuracy using TDOA

在相同时差测量精度情况下,异轨三星时差定位相对同轨三星时差定位具有较高的定位精度。从原理角度分析了异轨三星时差定位精度相对同轨三星时差定位精度较高的原因,给出了异轨三星时差定位误差表达式,并且通过设置对比试验分析,验证了异轨三星系统不同主星设置、异轨三星地面投影构型、异轨卫星时差测量精度、低轨卫星时差测量精度等因素对异轨三星时差定位精度的影响。结果表明,异轨三星时差在低轨卫星星下点连线两侧较大范围内定位精度较高,达到百米量级。

The different orbit three satellites TDOA(time difference of arrival)geolocation has higher geolocation accuracy than the same orbit three satellites TDOA geolocation with the same TDOA measurement accuracy.The cause of different orbit three satellites TDOA geolocation accuracy being superior to the same orbit satellites geolocation accuracy is analyzed in principle.The expression of geolocation error of different orbit three satellites TDOA geolocation is proposed.The influence of the different main satellite settings of different orbit three satellites system,the configuration of projection point of different orbitthree satellites on the ground,the accuracy of different orbit satellites TDOA measurement accuracy,the accuracy of low orbit satellites TDOA measurementaccuracy and other factors affect the geolocation accuracy of different orbitthree satellites TDOA is verified by setting comparative simulations.The results show that the geolocation accuracy can reach 100 meters in larger areas on both sides of the connection of two projection points of the two satellites on thesame orbit.