基于方差分量估计确定GPS/BD2组合定位先验权比

摘要

由于GPS与北斗二代(BD2)存在系统差异,两系统进行组合定位时,需合理确定两系统观测值的权比.为此,采用Helmert方差分量估计方法对两个系统的伪距观测值与相位观测值在伪距单点定位与相位相对定位时的权比进行分析.结果表明:Helmert方差分量估计可以得到GPS/BD2组合定位时的合理权比,即伪距观测值先验权比为2:1,相位观测值权比为1:1.%The optimum weight ratio of different observation values should be obtained in combined GPS-BD2 positioning since there is a systematic difference between GPS and BD2. The variance component estimation (VCE) formula is used to determine the variance-ratios of GPS and BD2 observations in the pseudorange single point posi tioning and phase relative positioning. The statistics of RMS of positioning errors with different weight ratios indicate that the results of VCE are reasonable and the prior weight ratios of GPS-BD2 pseudorange and phase observations can be 2' 1 and 1:1 respectively.