伪距单点定位两域联合平差解的等价性分析

针线性观测模型观测值域联合平差解和平差值域联合平差解完全等价，但实际中联合平差的观测模型多为非线性模型，参数估计时常常需要进行线性化处理，存在线性化引起的模型误差，该误差对两域平差解的等价性影响值得探讨. 以伪距单点定位(SPP)为例，论文推导了其平差值域联合平差求解公式，分析了两域联合平差不能完全等价的原因，并用实例进行了数值对比. 研究表明:在配置相同的情况下，不同全球卫星导航系统(GNSS)组合SPP的两域平差位置解在毫米量级上数值相同，就SPP应用而言，两域平差解可认为相同. 论文内容对于一些GNSS其他应用也具有一定的参考意义. 

Equivalence analysis of two-domain combined adjustment solutions of pseudo-range single point positioning

The combined adjustment solutions of the linear observation model in the observation domain and in the adjustment range are completely equivalent. However, in practice, the observation models of the combined adjustment are mostly nonlinear, which always need to be linearized in parameter estimation, resulting in linearized model error. The influence of this error on the equivalence of the two-domain adjustment solutions remains to be discussed. Thus, taking pseudo-range single point positioning (SPP) as an example, the solution formulas of the combined adjustment in the adjustment range of the observation model are deduced in this paper, on which the reason why the two-domain combined adjustment cannot be completely equivalent under the SPP model is presented and a numerical analysis is carried out with the example data. Research shows, the two-domain adjustment solution of SPP cannot be equivalent because it is assumed that the initial value of each iteration solution of a single system is the same as that of the combined adjustment of the observation range. And under the same configuration, the two-domain adjustment position solutions of different Global Navigation Satellites System (GNSS) combined SPP are the same value on the order of millimeter, that is, for the application of SPP, the two-domain adjustment solutions can be considered the same. The content of this paper also has certain reference significance for some other GNSS applications.