GPS双频快速定位的数据处理研究

Data processing research of GPS dual frequency rapid positioning

对于仅观测几个历元的GPS快速定位,用LS估计未知数的法方程严重病态,又由于观测噪声不可避免,导致模糊度的浮点解与准确值的差值很大,方差—协方差阵也不能准确反映浮点解的精度信息,这种情况下采用LAMBDA法也难以求出正确的模糊度。本文研究了GPS快速定位方程的病态特点以及采用消除电离层影响的载波相位与测码伪距观测值的组合求解双差模糊度浮点解的方法。计算表明该方法可避免GPS快速定位方程的病态性,提高模糊度浮点解的精度。

For GPS rapid positioning only by a few epochs＇ observations, the normal equations using leastsquare principle axe seriously ill-conditional, and the observation noise is inevitable, which cause ‘float＇ solution of ambiguities has large deflection compared with the accurate solution. In this case, it is difficult to acquire reliable solution with LAMBDA method. In this paper, the ill-conditional characteristics of normal equations and ambiguity resolution method using combinations of ionosphere-free carrier phase observations and code pseudorange observations were studied. Examples show that this method can avoid ill-condition problem of GPS rapid positioning equations and improve the precision of float solution of ambiguity.