一种单频单历元BDS／GPS组合整周模糊度解算方法

针对单频单历元组合载波相位差分技术(RTK)定位过程中存在的秩亏及模糊度解算病态等问题,提出了一种模糊度降相关的新方法。该方法引入伪距观测值进行辅助解算。首先采用经验分权法对伪距与载波相位观测值分配权重,并通过加权最小二乘法获得整周模糊度浮点解及协方差。然后通过对整周模糊度浮点解的方差-协方差矩阵进行降序排列和剔除病态模糊度。最后利用修正后的浮点解迭代搜索模糊度的整数解。试验结果表明而且可以起到良好的模糊度降相关的效果定位。 

An Ambiguity Algorithm for Single Frequency and Single Epoch Combination of GPS and BDS

Aiming at the problem of rank-defect and ill-conditioned ambiguity resolution in the process of single frequency single epoch combined RTK positioning, a new method for ambiguity decorrelation is proposed, in which pseudorange observations is introduced as auxiliary solution.First, we adopt the empirical decentralization method to assign weights to the pseudorange and carrier phase observations, and obtain the floating resolution of ambiguities by weighted least squares. Then the ill-conditioned ambiguity resolution can be eliminated by the descending order of variance-covariance matrix of the floating resolution of ambiguitiesand Cholesky triangular decomposition. Finally, we use the modified floating solution toiterate the search of the integer solution of ambiguity. The experimental results show that the down-correlation algorithm can not only improve the positioning accuracy, but also can reduce the correlativity of the ambiguity, which is suitable for RTK positioning.