FY3C卫星星载BDS与GPS数据质量分析与融合定轨  

FY3C Satellite Onboard BDS and GPS Data Quality Evaluation and Precise Orbit Determination

作　　者：李文文[1] 李敏[1,2] 赵齐乐 施闯[1,2] 郭向 孟祥广[3,4] 杨忠东 LI Wenwen;LI Min;ZHAO Qile;SHI Chuang;GUO Xiang;MENG Xiangguang;YANG Zhongdong(GNSS Research Center,Wuhan University,Wuhan 430079,China;Collaborative Innovation Center for Geospatial Technology,Wuhan 430079,China;National Space Science Center,Chinese Academy of Sciences,Beijing 100190,China;Beijing Key Laboratory of Space Environment Exploration,Beijing 100029,China;National Satellite Meteorological Center,China Meteorological Administration,Beijing 100081,China)

机构地区：[1]武汉大学卫星导航定位技术研究中心,湖北武汉430079 [2]地球空间信息技术协同创新中心,湖北武汉430079 [3]中国科学院国家空间科学中心,北京100190 [4]天基空间环境北京重点实验室,北京100029 [5]中国气象局国家卫星气象中心,北京100081

出　　处：《测绘学报》2018年第B12期9-17,共9页Acta Geodaetica et Cartographica Sinica

基　　金：国家自然科学基金(41274049; 41375041; 41274049; 41375041; 41231174);国家863计划(2014AA123101);地球空间环境与大地测量教育部重点实验室开放研究基金(15-02-05)~~

摘　　要：本文基于FY3C卫星2015年5月的星载GPS与BDS双频观测数据,开展了FY3C卫星星载BDS与GPS数据融合精密定轨研究。星载GPS和BDS数据质量分析表明,98%以上的历元能观测到4颗及以上的GPS卫星,而仅有35%的历元能观测到4颗以上的BDS卫星,且星载BDS数据的伪距多路径存在随高度角、方位角和频率变化的bias。精密定轨研究表明,基于单独GPS数据精密定轨的重叠弧段三维RMS平均RMS优于20mm,表明其轨道一致性较好,可作为融合精密定轨检核的参考轨道。等权处理GPS和BDS数据时,由于BDSGEO轨道与钟差误差会引起所有卫星观测值模型化误差增加,联合定轨精度仅在80mm量级。禁用BDSGEO观测值或者对其进行降权后,联合定轨的重叠弧段比较均在18mm,与GPS轨道相比的轨道差异均仅在10mm,表明其和单独GPS定轨精度一致。To analyze the precise orbit determination (POD) performance with combined onboard GPS and BDS data,we collect one-month worthy of BDS and GPS dual-frequency data from FY3C satellite during May 2015.The onboard BDS and GPS data quantity and quality are evaluated.It is revealed that there are over 98% epochs with 4 or more GPS satellites available,but only 35% epoch can observed 4 or more BDS satellites.Similar with the ground BDS data,the code-carrier divergences are also found in the onboard FY3C BDS data with fluctuations exceeding 1 m.However,these multipath error variations are observed not only related to elevations and frequencies but also to azimuths.The POD precision with only GPS data is evaluated by overlap comparison,showing good orbit consistency at 20 mm level (3D RMS).We perform the combined POD with three different strategies.It is shown that it can dramatically degrade the POD precision when BDS GEO (geosynchronous orbit satellites) observations are involved and treated with equal weighting,and the orbit precision is about 90 mm level compared to the GPS-only orbits.This should be attributed to the degraded BDS GEO satellite orbit and clock products.However,when performing combined POD with only BDS IGSO and MEO satellites along with GPS or by reducing the weights of GEO observations,the post-fit RMS of BDS LC residuals are comparable to that of GPS,and the orbit differences between combined POD and GPS-only POD are only at 10 mm level.This indicates that the precisions of combined POD using these two strategies are very consistent with respect to POD with GPS data alone.

关 键 词：低轨卫星 精密定轨 BDS GPS 轨道精度 

分 类 号：P228[天文地球—大地测量学与测量工程]