基于部分固定策略的多系统长距离基准站间模糊度快速解算

Fast Ambiguity Resolution Between GPS/GLONASS/BDS Combined Long-range Base Stations Based on Partial-fixing Strategy

基准站间整周模糊度的快速准确固定是实现网络RTK高精度快速定位的前提。对于GPS/GLONASS/BDS组合系统长基线,模糊度维数大幅度增加,加之观测噪声、大气残余误差等因素的影响,很难快速准确地固定所有模糊度,尤其是低高度角卫星模糊度。提出了一种基于部分固定策略的GPS/GLONASS/BDS组合网络长基线部分模糊度快速解算方法,以截止高度角、模糊度固定成功率以及Ratio值为主要参数,优选模糊度固定子集,以实现长距离基准站间模糊度快速固定。通过实测GPS/GLONASS/BDS三系统长基线数据的实验验证,部分模糊度固定方法可有效避免低高度角卫星对模糊度固定的影响,从而显著提高模糊度固定时的成功率及Ratio值,缩短长距离基准站间模糊度准确固定所需的时间。

Fast and correct ambiguity resolution（AR）between long-range base stations is the precondition of realizing high-precision Network Real-time Kinematic（NRTK）positioning.For long baselines in GPS,GLONASS and BDS combined systems,it is always difficult to fix all the ambiguities rapidly and correctly due to the dimensions of ambiguities increased greatly with the influence of measurement noise,residual atmosphere delay and etc.,which will be especially difficult for the ambiguities from low-elevation satellites.This paper proposed a fast partial ambiguities resolution（PAR）method with ambiguity subset adaptively selected based on the successively increased elevations for long baselines in GPS,GLONASS and BDS combined NRTK.Satellite cut-off elevation,ambiguity success rate and ratio are treated as major parameters to select the ambiguity subsets with ambiguity subset adaptively selected based on the successively increased elevations,and so that to realize fast and correct ambiguity resolution.The real measured long-baseline data which contain GPS,GLONASS and BDS observations are used in the experiments,and the results show that the PAR strategy can effectively avoid the influence of low-elevation satellites on AR fixing,which increase ambiguity success rate and Ratio significantly and of course shorten the required time of correct AR for long baselines in NRTK.