北斗坐标框架精度估算方法研究

Research on Accuracy Evaluation Method of Beidou Coordinate Frame

从RNSS(radio navigation satellite system)米级服务角度给出了BDCS(Beidou coordinate system)实现精度估算方法,包括广播星历定位法、精密星历与广播星历比对法和卫星激光测距(satellite laser ranging,SLR)坐标估计法。广播星历定位法适用于用户对参考框架实现精度的实时监测,但监测精度受限于广播星历精度。轨道比对法引入了事后精密产品,监测精度较高,但其时效性相对较差。SLR坐标估计法不受电离层延迟和卫星钟差影响,在三种方法中精度最高,但由于激光测距数据量较少,无法做短期监测。结果表明,三种方法估算BDCS与ITRF对齐精度均为厘米级。最后,在中俄卫星导航系统协作背景下,估算了BDCS和PZ-90对齐精度,结果表明,两者在厘米量级对齐,能够满足米级定位用户应用需求。随着北斗三号广播星历精度的提升和SLR的发展,上述三种方法的估算精度将会进一步提高。

From the perspective of RNSS meter-level services,BDCS implementation accuracy evaluation methods are given,including broadcast ephemeris positioning method,precise ephemeris and broadcast ephemeris comparison method,and satellite laser ranging(Satellite Laser Ranging,SLR)coordinate estimation method.The broadcast ephemeris positioning method is suitable for users to realize real-time monitoring of the accuracy of the reference frame,but the monitoring accuracy is limited by the accuracy of the broadcast ephemeris.The orbital comparison method introduces post-precision products with high monitoring accuracy,but its timeliness is relatively poor.The SLR coordinate estimation method is less affected by the ionospheric delay and is not affected by satellite clock errors.It has the highest accuracy among the three methods.However,due to the small amount of laser data,it cannot be used for short-term monitoring.The results show that the accuracy of the three methods to evaluate the alignment of BDCS and ITRF is at the centimeter level.Finally,in the context of Sino-Russian satellite navigation system cooperation,the alignment accuracy of BDCS and PZ90 was evaluated.The results show that the two are aligned on the centimeter level,which can meet the application requirements of meter-level positioning users.With the improvement of Beidou-3 broadcast ephemeris accuracy and the development of SLR,the evaluation accuracy of the above three methods will be further improved.