统计定轨中随机模型的验后估计  

THE A POSTERIORI ESTIMATION OF STOCHASTIC MODEL IN STATISTICAL ORBIT DETERMINATION

作　　者：张飞鹏[1] 黄煇 李雅勤[2] 冯初刚[1] 朱元兰[1] 

机构地区：[1]中国科学院上海天文台天文地球动力学中心,上海200030 [2]武汉测绘科技大学地球科学与测量工程学院,武汉430079

出　　处：《天文学报》2000年第2期129-138,共10页Acta Astronomica Sinica

基　　金：国家攀登项目!( 970 2 3 1 0 0 3 );国家自然科学基金!重点项目 ( 1 983 3 0 3 0 );中科院"九五"基础性研究重大项目!(KJ951 -1- 1

摘　　要：在卫星精密定轨中 ,对资料的加权一般是采用经验的方法 .本文采用赫尔默特(Helmert)方差分量估计方法 ,对Lageos2卫星 6个月的SLR资料进行试算 ,统计了各台站的验后方差 .结果表明 ,用验后方差估计的方法可以得到各台站大致合理的权重 。The determination of the precise orbits of artificial satellites by taking advantage of several types of satellite tracking techniques has become a tendency today. Especially for multidisciplinary satellites, in order to guarantee their success, several tracking equipments are usually collocated. In the precision orbit determination (POD) by using either single or multiple kinds of tracking techniques, there always exists a problem of how to weight the observations. For using single kind of tracking techniques, observation accuracy would be different not only among each station, but also for the same station due to temporal variations. For using multi technique to determine satellite orbits, there might exist technical differences. In POD for an artificial satellite with dynamic statistic method, the data weights are defined by W=σ 2 0R -1 with variance covariance matrix R and the unit variance σ 2 0, which can be an arbitrary positive number. Generally, R is unknown and so W cannot be determined properly. In practical computations, there are usually two approaches to weight the observations. One utilizes directly the standard deviation σ usually supplied in the data file and another comes from experience. Because standard deviation in data file denotes only the internal consistency but not the real observation precision, many institutes use only the latter or both of them. Neither the data file supplied σ nor the empirical method are good in determining the proper data weights due to the variational situations. This paper uses the Helmert method of variance component estimation (VCE) in order to obtain a set of proper data weights. The VCE method can be used to get the a posteriori variance components of the observations for data weighting. According to this method, observations can be divided into several groups in terms of instruments, error sources, accuracies, and so on. Through VCE, the variance factors for each group can be estimated after POD an

关 键 词：卫星精密定轨 数据加权 统计定轨 随机模型 

分 类 号：P135[天文地球—天体力学]