Estimation of Signal-to-Noise Ratio from Pulsed Coherent Doppler Lidar Measurements under Nonstationary Noise

Signal-to-noise ratio (SNR) is a key factor determining the accuracy of pulsed coherent Doppler lidar (PCDL) wind speed measurements. Therefore, information about SNR is important for interpreting measurement results. However, known approaches to determining SNR from PCDL raw data are not applicable to the case of the pulsed coherent Doppler lidar created at the Wave Propagation Laboratory of the Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, (WPL PCDL) due to significant nonstationarity of the noise component of recorded signals. In this work, a new technique for estimating the signal-to-noise ratio from PCDL measurements accounting for noise nonstationarity is developed. The technique was tested in an experiment with a Stream Line PCDL and the WPL PCDL. The practical applicability of the suggested technique is confirmed by comparing SNR estimates from joint measurements by these lidars.