双星定位系统的近地卫星联合定轨同质异质观测数据加权方法及应用

The Homogeneous/Heterogeneous Data Weighting Method of LEO Combined Orbit Determination Based on BI-Satellite Positioning System with Its Application

针对双星定位系统的近地卫星联合定轨中的多源观测数据的融合处理问题,建立了同质观测数据的二步系统误差修正的改进的方差分量估计最优加权方法;分析指出异质观测数据的多源融合测量模型本质为多结构多参数的非线性回归模型,建立了异质观测数据的模型结构特征分析和方差分量估计相结合的最优加权方法.设计了两类观测数据最优加权及联合定轨参数估计的实现算法,并以双星及备份星的距离和同质观测数据以及双星距离和与星敏感器测角的异质观测数据为例,进行了联合定轨仿真实验.理论分析和仿真计算结果表明:对于同质观测数据联合定轨,采用二步系统误差修正的方差分量估计法,可以获得比传统的经验加权算法更优的定轨精度;对于异质观测数据联合定轨,通过引入表征模型结构特征的加权因子,与平均加权方式相比,近地卫星及静地卫星的联合定轨精度均得到一定程度的改善.

Aiming at combined orbit determination （COD） multi-source data fusion for low earth orbit（LEO）based on bi-satellite positioning system（BPS）, an improved variance component estimation （VCE） optimal weighting method of homogeneous data is established with two-step system errors correction. And then an integrated optimal weighting method based on model structure characteristics analysis and VCE estimation of heterogeneous data is put forward by analyzing the essence of multi-source fusion measure model which is a multi-structural, multi-parametric, non-linear regression model. Then the algorithm of optimal weighting and COD parameters estimation is designed, and two kinds of COD simulation experiments are carried out by processing homogeneous data of hi-satellite range sum and its back-up satellite data, heterogeneous data of bi-satellite range sum data and star sensor angle data. Theoretical analysis and simulation computations show that improved VCE method based on two-step system errors correction can gain higher precision than that of traditional experience weighting method for COD of homogeneous data weighting. At the same time, by introducing weighting factor which denotes model structure characteristics and proves the designed optimal weighting algorithm, the amelioration of COD precision of LEO and bi-satellite gain to some extent is feasible from practical application.