BDS中距离参考站三频整周模糊度确定方法

The algorithm of triple-frequency integer ambiguity resolution between middle-range BDS reference stations

针对北斗卫星导航系统(BDS)中距离参考站整周模糊度受电离层延迟误差和对流层延迟误差影响难以正确固定的问题,提出了一种BDS中距离参考站三频整周模糊度确定方法.首先利用B2,B3频率观测值确定B2-B3超宽巷整周模糊度;利用B2-B3超宽巷组合观测值和B1-B3宽巷组合观测值所受电离层延迟误差较接近的特性,确定B1-B3宽巷整周模糊度,根据三频整周模糊度的线性关系确定B1-B2宽巷整周模糊度;进一步利用B1-B3和B1-B2消电离层组合观测值及对应的整周模糊度可分解的特点,解算窄巷整周模糊度和相对天顶对流层延迟误差,最后搜索确定窄巷整周模糊度.使用实测的连续运行参考站(CORS)网BDS三频观测数据进行算法验证.结果表明:该方法可正确有效的实现BDS中距离参考站间三频载波相位整周模糊度的快速解算.

To solve the problem that integer ambiguity between middle-range reference stations in BDS is difficult to be fixed correctly due to the influence of ionospheric delay error and tropospheric delay error,an algorithm of triple-frequency integer ambiguity resolution between middle-range BDS reference stations was proposed.Firstly,the frequency observations of B2 and B3 were used to determine B2-B3 extra-wide-lane integer ambiguity.Then,B1-B3 wide-lane integer ambiguity was solved by using the closer characteristic of ionospheric delay error between B2-B3 extra-wide-lane and B1-B3 wide-lane combination observation,and B1-B2 wide-lane integer ambiguity can be fixed according to the linear relationship of triple-frequency integer ambiguity.Furthermore,B1-B3 and B1-B2 ionosphere-free combination observation and the decomposable characteristic of the corresponding integer ambiguity were used to estimate narrow-lane integer ambiguity and relative zenith tropospheric delay error,and then narrow-lane integer ambiguity can be finally fixed by search mode.This algorithm is tested by the measured triple-frequency data of BDS CORS network.The results show that triple-frequency carrier phase integer ambiguity between middle-range BDS reference stations can be fixed accurately and effectively with the method.