The wind parameter estimates from a state-of-the-art 2-μm coherent lidar system located at NASA Langley, Virginia,
named VALIDAR (validation lidar), were compared after normalizing the noise by its estimated power spectra via the
periodogram and the linear predictive coding (LPC) scheme. The power spectra and the Doppler shift estimates were the
main parameter estimates for comparison. Different types of windowing functions were implemented in VALIDAR data
processing algorithm and their impact on the wind parameter estimates was observed. Time and frequency independent
windowing functions such as Rectangular, Hanning, and Kaiser-Bessel and time and frequency dependent apodized
windowing function were compared. The briefing of current nonlinear algorithm development for Doppler shift
correction subsequently follows.