BD-2星载原子钟长期在轨性能评估

利用WHU和GFZ提供的2013-01-01~2018-05-01北斗精密钟差数据，从原子钟相位、频漂、频率准确度和频率稳定度指标等方面对BD-2星载原子钟的长期在轨性能进行评估。结果表明，相位数据连续性和稳定性不佳，调相操作频繁；频漂维持在10-18~10-17 /s量级；准确度处于10-11量级，比较稳定；万秒稳定度在10-14~10-13量级，MEO卫星相较于GEO和IGSO卫星更加稳定。此外，分析原子钟切钟对频漂、准确度和稳定度的影响，并给出BD-2卫星钟的切换信息。

Long-Term Performance Assessment of BD-2 On-Board Atomic Clocks

BDS precise clock offset data from 2013-01-01 to 2018-05-01 are provided by WHU and GFZ. These data are used to evaluate the long-term performance of BD-2 on-board atomic clocks by phase, frequency, drift rate, frequency accuracy and stability. The results show that the phase data are not so continuous or stable and the phase modulations are frequent; the frequency drift rate maintains in 10-18-10-17/s; the frequency accuracy is stable in 10-11; the frequency stability in ten-thousands is about 10-14-10-13, and MEO satellites are more stable than GEO or IGSO satellites. Furthermore, according to the relationship between clock switching and frequency drift rate, accuracy and stability, the BD-2 satellite clocks switching information is verified and deduced.