一种改进的CIR法用于单历元模糊度解算

针对级联整周模糊度解算（CIR）法在载波相位和伪距观测噪声很大的场合，模糊度固定成功率很低这一问题，提出了一种改进的CIR法，该算法以CIR法为基础，利用排序和连续（逆）乔里斯基降相关法对每步最小二乘法求得的模糊度浮点解和协方差矩阵进行降相关，最后采用改进的最近点搜索（MAEVZ）法固定整周模糊度.仿真实验表明，在伪距观测噪声为2.0 m，载波相位观测噪声为0.03周的短基线环境下，CIR法单历元整周模糊度解算成功率已经低于5%，无法正确固定整周模糊度，而改进的CIR法单历元整周模糊度解算成功率仍能达到90%以上. 

Resolve Integer Ambiguity in Single Epoch Occasion by a Improved CIR Method

In order to solve the problem of the lower success rate to fix ambiguity with CIR method when the carrier phase observation noise and pseudorange observation noise are quite large, an improved CIR method was proposed. The ordering and multi-time (inverse) paired Cholesky decomposition method were used to reduce the correlation of ambiguity float solution and covariance matrix with the least square method. And then the MAEVZ method was used to search the fixed integer ambiguity. Simulation results show that, when the pseudorange observation noise is 2.0 m and carrier phase observation noise is 0.03 cycle, the success rate of integer ambiguity resolution is below 5% with CIR method and it can''t accurately fix integer ambiguity, however the success rate of integer ambiguity resolution is beyond 90% with the improved CIR method.