高分多模卫星星载BDS/GPS在轨数据分析与评估

Analysis and evaluation of on-orbit data of high-resolution multi-mode spaceborne BDS/GPS

高分多模卫星已在轨稳定运行,并使用星载BDS/GPS双频双模导航接收机实现了自主定轨功能。根据导航接收机在轨实测数据,开展了BDS模式和GPS模式下的载噪比、收星数等观测数据质量的对比分析,基于下传的原始观测数据完成了精密定轨解算,并采用内符合评估方法完成了实时定轨精度分析。经分析研究,导航接收机最高载噪比BDS模式较GPS模式高1 dB•Hz,平均可用星数BDS模式较GPS模式多0.6颗,精密定轨位置精度和速度精度BDS模式和GPS模式均在1.63~5.34 cm、0.0017~0.0046 cm/s之间,实时定轨位置精度和速度精度BDS模式和GPS模式均在3.10~4.23 m、0.00291~0.00394 m/s之间。结果表明,BDS信号与GPS信号的载噪比、可用星数和定轨精度均基本相当,表明BDS已具备为航天器用户独立提供时间、位置及速度等信息服务的能力。

The high-resolution multi-mode(GFDM)satellite has been operating steadily in orbit and has achieved autonomous orbit determination capability with the spaceborne dual-frequency,dual-mode BDS/GPS navigation receiver.Based on the on-orbit test data of the navigation receiver,a quality analysis of the observation data such as carrier-to-noise ratio and number of received satellites in both BDS and GPS modes is performed.The precise orbit determination calculation is completed based on the down-transmitted original observation data,and the real-time orbit determination accuracy analysis is completed by the internal coincidence evaluation method.After analysis and research,the maximum carrier-to-noise ratio of navigation receiver BDS mode is 1 dB•Hz higher than that of GPS mode,the average number of available stars in BDS mode is 0.6 more than that of GPS mode,and the precision orbit position accuracy and velocity accuracy of BDS mode and GPS mode are between 1.63~5.34 cm and 0.0017~0.0046 cm/s.Both the BDS mode and GPS mode are between 3.10~4.23 m,0.00291~0.00394 m/s.The position accuracy and velocity accuracy of real-time orbit determination of BDS mode and GPS mode are both between 3.10~4.23 m and 0.00291~0.00394 m/s.The results show that the carrier-to-noise ratio,the number of available stars and the orbit determination accuracy of the BDS signal are basically the same as those of the GPS signal,which indicates that the Beidou navigation satellite system is capable of independently providing time,position,velocity and other information services to spacecraft users.