星载原子钟性能分析方法比较研究

Comparison Research of Space Atomic Clock Performance Analyse Methods

卫星导航时间系统是影响导航系统性能的决定性因素。原子时钟作为频率标准,能够产生高准确度和高稳定度的标准频率信号,可以实现精确计时。因此在导航卫星上广泛使用原子钟作为频率标准。讨论了原子时钟频率稳定度的Allan方差、重叠Allan方差、Hadamard方差及重叠Hadamard方差算法,并对GPS卫星真实数据进行了频率稳定度分析。得出了不同的GPS卫星,星载卫星钟的稳定度不同。对于同一种类的GPS卫星,卫星钟的稳定度也存在差异,且GPS BLOCK IIR卫星具有较好的频率稳定度。

Satellite navigation time system is crucial factor to the navigation system performance. As the fre- quency standard, the atomic clock can give the high accuracy and high stability of the standard frequency signal which can be used to the precise timing, so the atomic clock is widely used in navigation satellites as the frequency standard. The algorithm to calculate the atomic clock frequency stability of Allan variance, overlapping Allan vari- ance, Hadamard variance and overlapping Hadamard variance are expounded and analyzed by simulation. It shows that different GPS satellites have different space satellite clock stability, even to the same type of GPS satellites are different for space satellite clock stability, and GPS BLOCK IIR satellites have better frequency stability.