不同卫星天线参数对BDS定轨定位精度的影响

论证了BDS精密单点定位时卫星天线参数与卫星轨道、钟差产品保持一致的必要性。基于4组不同卫星天线参数BDS精密定轨RTN3方向内符合精度,GEO卫星均在9.3、18.6、11.5cm左右,IGSO卫星均在1.7、4.2、2.7cm左右,MEO卫星均在2.1、5.1、4.8cm左右,在R方向的差异小于5mm,在TN方向的差异最大为2.4cm;定轨结果与GFZ的事后精密产品比较,RTN3方向外符合精度差异较明显,排除GEO卫星因定轨策略与GFZ差异较大的因素,IGSO和MEO外符合精度ESA和WHU相近,RTN3方向均在10cm以内,各分量上优于IGS和EST 1~10cm,其中TN方向差异最显著。在保持BDS PPP使用的卫星天线参数与卫星轨道、钟差产品一致的前提下,4组卫星天线参数定位精度相近,其中静态定位最后一个历元水平和高程方向坐标偏差均在5cm以内,动态定位收敛后坐标偏差RMS水平方向在10cm以内、高程方向在15cm以内;使用ESA和WHU天线参数动态定位平均收敛时间在46min左右,IGS和EST天线参数动态定位平均收敛时间在56min左右,略差于基于GFZ事后产品的收敛时间,其平均收敛时间在34min左右。

The impacts of different satellite antenna parameters on BDS precise orbit determination and precise point positioning accuracy

The necessity that the satellite antenna parameters used in BDS PPP should be consistent with the satellite orbit and clock products is demonstrated. Based on four groups of satellite antenna parameters BDS precise orbit inner accuracy in RTN three-way, GEO satellites are all around 9.3、18.6、11.5 cm, IGSO satellites are around 1.7、4.2、2.7 cm, MEO satellites are about 2.1、5.1、4.8 cm, the difference of the orbit determination accuracy in the R direction is less than 5 mm, and the maximum difference in the TN direction is 2.4 cm. Compared with the GFZ's post precision products, the outer accuracy of RTN is significantly different, excluding the factors of the difference orbit determination strategy with GFZ in GEO, the IGSO and MEO orbit precision are similar between ESA and WHU, and the RTN is within 10 cm in all directions, which are better than IGS and EST from 1 cm to 10 cm in three components, where TN direction have the most significant difference. While keeping the satellite antenna parameters used by BDS PPP consistent with the satellite orbit and clock products, the positioning accuracy of the four satellite antenna parameters are similar, in which the last epoch coordinate bias of static PPP is within 5 cm, the RMS of kinematic PPP coordinate bias is within 10 cm in horizontal direction after convergence, and within 15 cm in vertical direction. The average convergence time of kinematic PPP based on ESA and WHU antenna parameters was about 46 min, while the average convergence time based on IGS and EST antenna parameters was about 56 min, slightly worse than the convergence time based on GFZ post-products, and its average convergence time was about 34 min.