Precise orbit determination of GEO satellite based on helmert variance component estimation method

Abstract

Precise orbit determination of GEO satellite is a difficult point in area of satellite orbit determination. In this essay, Helmert variance component estimation method is proposed to be applied in the determination of the weights of observations in combined orbit determination. Through making χ 2 test of the results after united adjustment, it is found that when combining transfer data and pseudo-range data in orbit determination, their weights cannot be taken as equal, and thus Helmert variance component estimation is applied in the POD of GEO satellite. Numerical experiment proves that if each station determines its weight respectively, then too many groups will deteriorate the stability of computation and cause failure of orbit determination, while determining the weights by assorting data according to station type is a grouping strategy used in the orbit determination of GEO satellites. After re-determining the weights, the results pass through the χ 2 test and distinct improvement appeared in orbit accuracy via laser assessment, which indicated that the Helmert variance component estimation method is applicable for the combined orbit determination of GEO satellites using different observations. © 2012 Springer-Verlag.