BDS13号卫星星载原子钟在轨特性分析

On-orbit Feature Analysis of BDS C13 Satellite Clock

北斗C13号卫星由于存在故障，2014年底停止提供服务。2016年10月12日原C15号卫星改变编号为C13号卫星继续提供服务，其运行轨道由原先的MEO轨道变换至1GSO轨道。本文针对C13卫星星载原子钟相位、频率、频漂及拟合残差和频率稳定度指标进行了评估分析，利用56个月的GBM精密钟差数据分析了C13号卫星变换前后的星载钟特性指标并评价了现阶段其在轨服务性能。数值结果显示，变换后C13号卫星经过星载钟在轨调整，其星载原子钟的频漂、拟合残差及稳定度均趋于稳定，已达到卫星原子钟设计标准，能够为导航定位授时提供正常服务。

BDS C13 satellite stopped providing service in the end of 2014 due to abnormal behavior. On October 12th, 2016, the C15 satellite is renamed C13 to provide services, and the orbit is changed from the original MEO orbit to IGSO orbit. In this paper, the phase, frequency, frequency drift, fitting residual and stability features of the C13 atomic clock are evaluated and analyzed. Based on the 56-month GBM precise clock data, both the features of the new and old C13 satellite clocks are ana- lyzed. Meanwhile the current service status of the C13 atomic clock is evaluated. The numerical results show that the frequency drift, fitting residual and stability of the C13 satellite clock are becoming stable through some reasonable on-orbit adjustment. At present, the Cl3 satellite clock can achieve the design standards and provide normal service for navigation, positioning and tim- ing.