Speed range is an important specification of coherent Doppler wind lidar (CDWL). However, it is difficult to identify the lower speed bound of CDWL, because the Doppler signal is often overlapped or covered by relative intensity noise (RIN) at the low-frequency end of the spectrum. Therefore, how to distinguish the Doppler signal and the RIN at the low frequency is always an important issue. In the optical information processing, Rayleigh criterion specifies the spatial resolution limit, which is the minimum distance between the two distinguishable Airy disks. Due to the rigorous one-to-one correspondence between optical signals and electrical signals in photoelectric conversion, Rayleigh criterion can be extended to the electrical signal processing. We mapped the Doppler signal and RIN into the Airy disk profile and used the generalized Rayleigh criterion to study the signal resolution limit to define the lower speed bound of the system. The comparative experiments were carried out and the results were consistent with the generalized Rayleigh criterion. It shows that the generalized Rayleigh criterion is available and effective and can be used as a new method for the signal resolution on coherent Doppler wind measurements.

中文翻译：

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相干多普勒测风信号分辨率的广义瑞利准则

速度范围是相干多普勒测风激光雷达（CDWL）的重要规格。但是，由于多普勒信号经常在频谱的低频端被相对强度噪声（RIN）重叠或覆盖，因此很难确定CDWL的较低速度范围。因此，如何在低频下区分多普勒信号和RIN一直是一个重要的问题。在光学信息处理中，瑞利准则指定了空间分辨率极限，该极限是两个可区分的艾里斑之间的最小距离。由于光电转换中光信号和电信号之间严格的一对一对应关系，因此可以将瑞利准则扩展到电信号处理。我们将多普勒信号和RIN映射到Airy磁盘剖面中，并使用广义瑞利准则研究信号分辨率极限，以定义系统的较低速度范围。进行了对比实验，结果与广义瑞利准则一致。结果表明，广义瑞利准则是有效的，可以作为相干多普勒测风信号分辨率的一种新方法。