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频率短期稳定度问题是多普勒测速关键技术之一。本文强调对多普勒测速频率短期稳定度的要求应该用方差σ~2(2,t_d、τ)表示。估算了σ~2(2,t_d、τ)与阿仑方差的差别,结果表明:当飞行体在近、中距离时二者差别可能要以数量级计;而在远距离时二者基本上相等。文中详细讨论了脉冲测速雷达的频率短期稳定度与连续波时的差别,并给出近似计算公式。此外还讨论了有规干扰和滤波器对频率短期稳定度的影响,给出估算方法,并举例说明。
Frequency short-term stability is one of the key technologies of Doppler velocity measurement. This paper emphasizes that the requirement of short-term stability of Doppler velocimetry frequency should be expressed as variance σ ~ 2 (2, t_d, τ). The difference between σ ~ 2 (2, t_d, τ) and the Allan variance is estimated. The results show that the difference between the two can be orders of magnitude when the flying object is in the near and middle distance, and the two are substantially equal . In this paper, the difference between the short-term frequency stability and the continuous wave of pulse tachyarctic radar is discussed in detail and the approximate formula is given. In addition, we also discuss the influence of the regular interference and the filter on the short-term stability of the frequency, give an estimation method and give an example.