BDS网络RTK参考站三频整周模糊度解算方法

北斗卫星导航系统是目前唯一一个全星座提供三频观测数据的卫星导航定位系统,三频观测值有助于载波相位整周模糊度的快速、准确固定。本文提出了一种BDS网络RTK参考站三频整周模糊度解算方法。首先利用B2、B3频率的观测值及严格的模糊度固定标准确定超宽巷整周模糊度,将固定的超宽巷整周模糊度与其他宽巷整周模糊度的线性关系作为约束条件,然后估计宽巷整周模糊度、相对天顶对流层延迟误差和电离层延迟误差,并搜索确定宽巷整周模糊度。利用固定的宽巷整周模糊度与三频载波相位整周模糊度的整数线性关系,将线性关系加入载波相位整周模糊度参数估计观测模型中,然后确定载波相位整周模糊度。使用实测的CORS网BDS三频观测数据进行算法验证,结果表明,该方法可正确有效地实现参考站间三频载波相位整周模糊度的快速解算。

The Algorithm of Triple-frequency Ambiguity Resolution between BDS Network RTK Reference Stations

BeiDou navigation satellite system is currently the only system which the whole constellation offers triple-frequency observation data, triple-frequency observation is conducive to carrier phase ambiguity fixing quickly and accurately.The algorithm of triple-frequency integer ambiguity resolution between BDS network RTK reference stations is proposed.The observation of B2 frequency and B3 frequency and the strict criterion of ambiguity fixing are used to determine extra-wide-lane integer ambiguity.The linear relationship between fixed extra-wide-lane integer ambiguity and other wide-lane integer ambiguity is selected as constraint conditions, then the wide-lane integer ambiguity, relative zenith tropospheric delay error and ionospheric delay error are estimated and the wide-lane integer ambiguity can be fixed by search mode.There is a kind of integer linear relationship between fixed wide-lane integer ambiguity and triple-frequency carrier phase integer ambiguity, this linear relationship is added to the observation model of carrier phase ambiguity parameter estimation and the integer ambiguity can be fixed.This algorithm is tested by the measured triple-frequency data of BDS CORS network.The results indicate that triple-frequency carrier phase ambiguity can be fixed accurately and effectively with the method.