Novel nonlinear adaptive Doppler shift estimation technique (NADSET) for the coherent Doppler lidar system VALIDAR

摘要

A novel Nonlinear Adaptive Doppler Shift Estimation Technique (NADSET) is introduced in this paper. The quality of Doppler shift and power estimations by conventional Fourier-transform-based spectrum estimation methods deteriorates rapidly in low signal-to-noise-ratio (SNR) environment. The new NADSET algorithm compensates such deterioration in the quality of wind parameter estimates by adaptively utilizing the statistics of Doppler shift estimate in strong SNR ranges and identifying sporadic range bins where good Doppler shift estimates are found. NADSET is based on the nature of continuous wind profile and significantly improves the accuracy and the quality of Doppler shift estimates in low SNR ranges. The authenticity of NADSET is established by comparing the trend of wind parameters with and without NADSET applied to the lidar returns acquired over a long period of time by the coherent Doppler lidar system VALIDAR at NASA Langley Research Center in Virginia.