无几何距离组合联合MW组合探测周跳的改进算法

Modified Algorithm for Detecting Cycle Slips Using Geometry-Free Combination and Melbourne-Wu bbena Combination

指出了以往使用无几何距离组合联合MW组合探测GPS载波相位周跳的不足之处,提出3个改进的措施:(1)使用双低通滤波器平滑伪距;(2)利用周跳在高阶差分中的时间序列特征,使用最小二乘法定位和估算周跳;(3)对解算得到的周跳浮点解进行条件搜索,得到周跳的整数解。模拟试验表明改进后的算法不仅探测独立周跳的成功率很高,而且探测非独立周跳的成功率也很高。本文的方法已成功用到CHAMP卫星的GPS载波相位的周跳探测中,表明该算法能够用来探测高动态GPS的周跳。

The previous methods have disadvantages in which of geometry-free linear combination and Melbourne-Wuebbena linear combination for detecting cycle slips in GPS carrier phase. Some measures for improving the method are presented as follows. （1） Using double lowpass filter to smooth code pseudoranges; （2） Using least square estimator to locate and fix cycle slips according to characteristics in highly order differential time series; （3） Finding integer number of cycle slips from real-valued cycle slips using the search algorithm under certain conditions. The simulation reveals that the success ratio for detecting independent and dependent cycle slips by the modified algorithm is higher than previous one. The method is successfully used to detect cycle slips in GPS carrier phase of CHAMP satellite. The result proves that the new algorithm can detect higher dynamic GPS cycleslips.