中文摘要：

介绍了广播星历精度评估的基本原理和方法,并利用2013-01～2015-04共28个月的广播星历数据,分析比较了北斗不同类型卫星的轨道精度、钟差精度及整体精度的短期和长期变化趋势。结果表明,GEO卫星广播星历的轨道精度约为1.8m,钟差精度优于6ns;IGSO和MEO广播星历的轨道精度优于1.2m,钟差精度优于4ns,整体上优于GEO卫星。从长期变化趋势来看,北斗广播星历的精度有逐渐提高的趋势。

英文摘要：

We introduce the basic accuracy assessment theory and method of broadcast ephemeris.We then analyze and compare the short and long-term trends of the broadcast ephemeris accuracy,clock bias accuracy and SISRE accuracy of different types of BDS satellites,using 28-month-long broadcast ephemeris data from January 2013 to April 2015.The results show that the orbital accuracy of GEO satellites is about 1.8m,and the clock bias accuracy is better than 6ns.As for the IGSO and MEO satellites,orbital accuracy is better than 1.2mand clock bias accuracy is better than 4ns.These results are better than the accuracy of GEO satellites overall.The long-term trend of BDS broadcast ephemeris accuracy indicates that its accuracy has a tendency to improve gradually.