GPS单点测速方法的比较分析

Comparative analysis on velocity determination by GPS single point

针对GPS处于无基准站覆盖环境时无法通过差分运算获取载体速度的问题,对比分析伪距单点定位位置差分、原始多普勒频移观测值,以及载波相位导出的多普勒频移观测值等3种测速方法的有效性,分别开展静态实验和车载动态实验。结果表明:静态测速实验中伪距单点位置差分测速精度达0.4cm/s,由载波相位导出的多普勒频移观测值和原始多普勒频移的测速精度在水平方向上的速度误差小于10cm/s;动态环境下采用高精度GPS/INS组合导航系统提供的速度信息为基准,得到伪距单点位置差分、导出多普勒频移的测速误差均小于40cm/s,原始多普勒频移观测值方法得到的水平方向测速误差小于10cm/s。

Aiming at the problem that it is difficult for GPS to obtain the vehicle speed with differential algorithms in the environment without base station,the paper comparatively analyzed the effectiveness of three speed determination methods of the location difference of pseudorange single point positioning,the original Doppler frequency shift observation and the Doppler frequency shift observation derived from carrier phase.Then static experiment and vehicle dynamic experiment were carried out respectively.Result showed that in the static experiment,the precision of single point pseudo-range differential velocity determination could be up to 0.4cm/s,and both the velocity errors of Doppler frequency shift observations derived from carrier phase and the original Doppler frequency shift in horizontal direction could be less than 10cm/s;in the dynamic environment,high precision GPS/INS integrated navigation system was introduced to provide the velocity references,and both the velocity errors of pseudo-range single point location difference and the derived Doppler frequency shift could be less than 40cm/s,and the velocity error of original Doppler frequency shift observation in the horizontal direction could be less than 10cm/s.