基于残差统计的三类北斗卫星随机模型估计与特性分析

Three kinds of Beidou satellite’s stochastic model estimation and characteristic analysis based on residual statistics

基于北斗卫星的几何观测模型,处理3种型号接收机的4组短基线和零长度基线北斗观测数据,通过与MINQUE方法估计的随机模型进行比较,验证直接利用残差估值计算北斗观测值随机模型的可行性;在此基础上分析北斗卫星观测值高度角相关的精度、交叉相关性、空间相关性和时间相关性;结果表明北斗对地静止轨道(GEO)卫星的观测误差、空间相关性、时间相关性均大于倾斜同步轨道(IGSO)卫星和中轨道(MEO)卫星;北斗卫星的同类型观测值之间均具有较强的交叉相关性,不同类型观测值间的交叉相关性较弱,且随机模型的估计结果受接收机的内部误差和测站的外部误差影响。

Based on the geometric observation model of Beidou satellite,four sets of short baseline and zero length baseline Beidou observation data of the three types of receivers are processed.By comparing with the stochastic model estimated by MINQUE method,the feasibility of using residual estimation directly to calculate the stochastic model of Beidou observations is verified,and the calculation efficiency is improved.And the accuracy,cross correlation,spatial correlation and time correlation of the four types of observation data of the three types of Beidou satellites are analyzed respectively.The result indicates that the modeling error of observations,spatial correlations,and temporal correlations for geostationary earth orbit(GEO)satellites are larger than for inclined geosynchronous satellite orbit(IGSO)and medium earth orbit(MEO)satellites.For Beidou,the same type of observation has a strong cross-correlation between the two frequencies,and on the contrary,the cross correlation between different types of observations is weak.Furthermore,the stochastic model is governed by both the internal errors of the receiver and external errors on the site.