导航卫星原子钟频率漂移特性分析

Analyses of Frequency Drift Characteristic for Atomic Clocks of Navigation Satellites

介绍了原子钟频漂定义,总结了频率漂移率测试评定方法,比较分析了不同噪声情况下的频率漂移率估计方法,并用实验室真空状态铷钟的频率偏差数据和GPS卫星钟的精密星历数据进行了计算分析,表明铷钟都有明显频漂,GPSIIR铷钟的日漂移率在10-15量级,而铯钟频漂不是很明显。研究了频漂对原子钟时域稳定性影响规律,还利用模拟数据进行了计算分析,验证了方法的有效性。

The definition of frequency drift for atomic clock is first presented. And the method for testing frequency drift is summarized. The method for estimating frequency drift in the case of different noise is also compared. And then the frequency drift is calculated using the frequency offsets of rubidium clocks in the vacuum and the time errors of GPS satellite clocks. The results show that the frequency drift is obvious for all rubidium clocks and the daily frequency drifts of GPS IIR rubidium clocks is on the order of 10--15, and that the frequency drift for cesium clocks is, however, not obvious. The effect of frequency drift on the time-domain stability measures for atomic clocks is also studied, calculated and analysed based on simulated clock data. It shows that the effect is obvious and the corrected method is efficient.