动态GPS精密单点定位三种星历精度差异分析

针对传统的动态GPS中采用不同星历的定位精度问题,给出了无电离层模型数学方程,改正了电离层延迟、对流层延迟、多路径效应、相对论效应以及天线相位中心偏差等误差的影响,采用扩展Kalman滤波解算出每个历元时刻接收机坐标。采用Rapid、Final与RTS共3种不同星历产品计算KPPP,比较了3种不同星历解算结果。对比实验表明:使用Rapid星历计算KPPP结果与Final星历计算结果偏差很小,处于2cm之内,故在时效性要求较高的动态GPS工程应用中可以采用Rapid星历替代Final星历;而使用RTS星历计算结果与Final星历计算结果偏差1.3m,使用RTS星历定位精度低于Final、Rapid星历计算结果,但其具有实时定位的明显优势。

Accuracy difference analysis of three kinds of ephemeris on dynamic GPS precise point positioning

Aiming at the problem of traditional dynamic GPS positioning accuracy which using different ephemeris,presents the mathematical equation of ionospheric-free model,corrects the effect of ionospheric delay,tropospheric delay,multipath effect,the relativistic effect and the antenna phase center deviation error,then using extended Kalman filtering to calculate each epoch receiver coordinates.Using three kinds of different ephemeris products,namely Rapid Final and RTS ephemeris,to calculate KPPP,then compares three different ephemeris calculation results.Experiments show that:the bias of the KPPP results between using Rapid satellite ephemeris and Final satellite ephemeris is very small,always less than 2 cm,so we can use the Rapid ephemeris to replace Final ephemeris in the dynamic GPS project application which is requirements of timeliness;and the bias of the KPPP results between using RTS satellite ephemeris and Final satellite ephemeris is 1.3 m,the KPPP positioning accuracy of using RTS ephemeris is less than Final or Rapid satellite ephemeris,but it has obvious advantages of real-time positioning.