一种GPS最优选星及伪距定位方法

Optimal constellation selecting and pseudo-range positioning algorithm in GPS

在现有GPS的选星方法和伪距导航方程的基础上,提出了一种新的GPS选星方法和直接解算导航算法。先对现有的GDOP(几何精度因子)值选星法进行了简述,然后用卫星的仰角阀值筛选得到参与选星的卫星,再用星座四面体选星法进行最优选星,并提出了一种直接定位解算算法。最后用GPS星历数据进行选星试验,试验结果表明,四面体选星法计算简单有效,与现有的GDOP值选星法结果完全一致,直接定位解算算法精度可以达到10 m级,并且快速直接,对GPS的高精度快速定位具有参考意义。

Based on the existing constellation selecting and pseudo-range navigation equations in GPS positioning, a new constellation selecting method and a direct positioning algorithm were presented. Firstly, the existing geometric dilution of precision （GDOP） value selecting was introduced. Then the elevation threshold value was used to filter the satellites. Afterwards, a constellation-tetrahedron selecting method was used for selecting, and a direct positioning algorithm is presented. The tests with the GPS data of ephemeris and the direct positioning algorithm show that constellation-tetrahedron selecting method is simple and effective, and has the same results with the GDOP value selecting. The error of the direct positioning algorithm is decreased to about 10 m. The algorithm is fast and direct, which has reference significance on GPS fast positioning.