地影期间Multi-GNSS精密轨道精度分析

Accuracy analysis of Multi-GNSS precise orbit in shadow

IGS MGEX不同分析中心在事后精密定轨中采用不同的模型及策略,目前暂无统一合并的Multi-GNSS精密产品。本文采用三种策略分别研究GPS、Galileo和BDS产品精度及特性,为用户在使用不同产品时提供参考。首先,将GPS产品与IGS事后精密产品比较,除JAXA中心的qzf产品以外,所有中心GPS轨道产品精度为2.5cm。其次,选取GFZ中心产品作为参考,其它所有中心Galileo轨道产品RMS约为15cm;各分析中心BDS卫星轨道精度存在差异,尤其当卫星处于地影期时差异更为明显。第三,计算连续两天轨道的不连续性评价各中心Galileo和BDS轨道产品精度,结果表明TUM中心Galileo卫星轨道精度最高,COD中心完全光照中的BDS卫星精度最高,但当BDS卫星处于日蚀期时,GFZ和WUM中心轨道精度较高。

For IGS MGEX,individual center adopts different models in data processing,and has no integrated Multi-GNSS products so far. This contribution presents three methods for studying the accuracy and character of different Multi-GNSS products,which could do benefit for the users. First,it compares GPS products with IGS final product. The result shows that apart from GFZ orbit,RMS of all the other GPS orbits is 2. 5 cm. Afterwards,products from GFZ center are taken as reference. For Galileo satellites,RMS of satellite orbits in other centers is 15 cm on average. However,for BDS satellites,there are differences in RMS between different centers,especially for BDS eclipsing satellites. Finally,we calculate the day boundary discontinue to evaluate orbit accuracy of Galileo and BDS satellites. The result shows that TUM center owns the best Galileo orbit,COD center owns the best BDS orbit when satellite is in full sunlight.