中国DZT网ERP测量系统站网分析

Analysis of station network of ERP measurement system in China DZT network

为研究利用数字天顶仪(DZT)组网观测开展我国独立自主地球自转参数(ERP)测量技术和服务体系研究中站网的选取对测量精度的影响,以精度衰减因子(DOP)为精度评定指标,通过仿真实验研究分析了不同站点数量和影响空间几何构型的站点跨度及覆盖面积对测量精度的影响.结果表明:站点数量和网形几何强度(站间跨度和覆盖面积)对观测精度的影响具有相关性;测量精度与站间跨度呈中等相关性,与站点覆盖面积呈强相关性,且当站点数量较少时,站点的空间网形结构极大影响测量精度.给出了在备选站点下不同数量的最优方案,可为中国DZT网ERP测量系统网形设计提供参考.

To study the influence of the selection of the station network on the measurement accuracy in the independent earth rotation parameter(ERP) measurement technology and service system in China using multiple digital zenith telescope(DZT), the dilution of precision(DOP) was used as the accuracy evaluation factor,and the influences of the number of station and the station span and coverage area which could affect the spatial geometry on the accuracy of ERP were analyzed through simulation experiment.Results show that the observation accuracy is correlated with the number,span and coverage area of station.Among these factors, the measurement accuracy is moderately correlated with the station span and strongly correlated with the coverage area of station.The spatial structure of station affects the accuracy of ERP significantly when considering less station.The optimal solution with different numbers of station was given,which could provide reference for the network design of the ERP measurement system in China DZT network.