顾及星历数据龄期的北斗IGSO、MEO卫星空间信号精度分析

利用2013~2015年广播星历数据分析北斗系统3类卫星广播星历中星历数据龄期的特性，并针对北斗系统IGSO卫星和MEO卫星数据龄期分布特性，分析不同数据龄期条件下的两类卫星空间信号精度。结果表明，卫星数据龄期具有周期性，并和卫星所处轨道面具有一致性。对于IGSO卫星，平均数据龄期在1.7 h左右，最大数据龄期可以达到7 h。仅考虑轨道情况下，不同数据龄期条件下空间信号精度差异最大可以达到0.5 m。对于MEO卫星，平均数据龄期在11 h左右，最大数据龄期可以达到2 d甚至以上。仅考虑轨道情况下，不同数据龄期条件下空间信号精度差异IGSO卫星最大达到0.9 m。IGSO卫星2013~2015年平均URE分别为0.81 m、0.84 m、1.11 m；MEO卫星2013~2015年平均URE分别为0.84 m、0.82 m、1.04 m。

Signal-In-Space Precision Analysis for IGSO and MEO Satellites of BDS Considering the Age of Data

The paper analyzes the characteristics of AODE in broadcast ephemeris for different orbit of BDS from 2013 to 2015. According to the AODE distribution of IGSO and MEO, the signal-in-space accuracy based on different AODE is analyzed in the paper. The results show: AODE of satellites is in period and is consistent with the orbit. For IGSO satellites, the average AODE is about 1.7 hours, reaching to a maximum of 7 hours. Considering orbit alone, the URE of different AODE varies 0.5 m at the worst. For MEO satellites, the average AODE is about 11 hours, and the maximum reachedis two days. Considering orbit alone, the URE of different AODE varies 0.9 m for the worst. During 2013 to 2015,the average URE of IGSO satellites are 0.81 m, 0.84 m and 1.11 m; for MEO satellites they are 0.84 m, 0.82 m and 1.04 m.