北斗系统高轨卫星高精度定位模型病态性分析及改进方法

Analysis and Solution of Ill-conditioned Problems in BeiDou System High-precision High-orbit Satellite Positioning Model

分析了北斗卫星导航系统高轨卫星的运行特征,基于此解释了定位模型中出现病态性问题的原因。在网络实时动态基线处理中,针对这种病态性问题,通过对两个天顶对流层参数加以约束,提出了基于部分岭估计的模糊度浮点解快速解算的改进方法。该方法能够提高模糊度浮点解的精度,进而缩小浮点解的搜索空间。因此在此基础上结合最小二乘降相关分解法固定模糊度时,能够增大模糊度固定解的合格基线方差比值,从而提高模糊度固定解的准确率。实验算例的结果表明该算法的正确性和有效性。

The operation characteristic of high-orbit satellites of BeiDou navigation satellite system is analyzed in this paper,and based on it,the paper explains the ill-conditioned problems of the positioning model.According to the problems,a new ambiguity algorithm is proposed,which is based on partial ridge estimator through constraining the two zenith tropospheric parameter in the case of Network RTK baseline processing.As a result,the new approach can improve the precision and narrow the searching space of the float ambiguity solution.So,with the help of LAMBDA solution,the value of ratio and precision of the navigation and positioning can be raised.The tests given in the paper show that the new algorithm is valid and efficient.