两种预报轨道的BDS实时钟差估计与分析

BDS Real-time Clock Estimation and Analysis Based on Two Kinds of Predicted Orbit

基于iGMAS与武汉大学提供超快速轨道产品,以Geoscience Australia机构开源的GNSS处理软件ACS为平台,进行了BDS实时钟差估计实验,并对生成的产品进行了分析。实验结果表明,使用全球具有实时数据流的监测站,在以武汉大学最终钟差产品为参考钟差进行评估的情况下,基于武汉大学小时轨道估计的BDS实时钟差精度为0.25/0.67 ns(MEO/IGSO),而使用iGMAS超快速产品估计的钟差的精度为0.37/2.51 ns(MEO/IGSO),MEO卫星优于IGSO卫星,BDS-2与BDS-3均无明显分群差异。两类实时钟差产品的差异主要来自于轨道切换时产生的跳变。

Based on predicted orbit from ultra-fast orbit products provided by iGMAS and hourly products provided by Wuhan University and using ACS,an open source GNSS processing software of Geoscience Australia is as the software platform to estimate BDS real-time clock.Evaluated by WUM final clock,the experimental results show that the BDS real-time clock based on Wuhan University hourly orbit estimation is better,which is 0.25/0.67 ns(MEO/IGSO),while the BDS real-time clock based on iGMAS ultra fast products is 0.37/2.51 ns(MEO/IGSO).MEO satellite’s real-time clock is better than IGSO satellite’s.There is no significant difference between BDS-2 and BDS-3.The difference between the two kinds of real-time clock is mainly due to the jump caused by orbit switching.