BDS与GPS数据解算地球自转参数精度分析

Analysis of earth rotation parameters accuracy based on BDS and GPS data

针对我国利用BDS数据自主确定地球自转参数(ERP)时,需对其精度进行验证和分析的问题,该文利用我国境内及周边的GPS基准站数据以及MEGX网BDS数据进行ERP解算,对解算结果进行精度对比和分析。解算结果表明:利用BDS数据解算的ERP,在X方向极移和国际地球自转服务(IERS)公布值差值的RMS为0.6576mas,Y方向极移差值的RMS为1.0324mas,UT1-UTC差值的RMS为0.0853ms;利用GPS数据解算ERP,在x方向极移差值的RMS为0.4516mas,Y方向极移差值的RMS为0.5475mas,精度明显比利用BDS数据解算的要高,UT1-UTC差值的RMS为0.2153ms,比利用BDS数据解算的精度差。利用两种技术解算ERP发现极移参数存在明显的系统性误差,而UT1-UTC值不存在明显的系统性误差。结果表明,利用BDS技术确定地球自转参数精度虽然比GPS要差,但较之前成果有了很大提高。

Aiming at the problem of verifying and analyzing the precision of the earth rotation parameters(ERP) which needs to be determined independently by using BeiDou navigation satellite system(BDS) data in China,this paper used the global positioning system(GPS)reference station data in and around China and the BDS data of MEGX network to calculate the ERP,and the accuracy of the calculation results were compared and analyzed.The calculation results showed that RMS of the difference calculated by BDS data and the International Earth Rotation Service(IERS)was 0.6576 mas in X direction polar motion,and was 1.0324 mas in the Y direction polar motion,was 0.0853 ms in UT1-UTC;RMS of the difference calculated by GPS data and IERS was 0.4516 mas in X direction polar motion,was 0.5475 mas in the Y direction polar motion,which was obviously better than that of BDS data,was 0.2153 ms in UT1-UTC,which was worse than that of BDS data.Using two techniques to solve the ERP,it was found that there were obvious systematic errors in the pole motion parameters,and there was no obvious systematic error in the UT1-UTC values.The research results showed that using BDS technology to determine the accuracy of the ERP was worse than GPS,but the data accuracy was greatly improved compared with the previous ones.