Analysis On Measure Error Of Direct Detection Wind Lidar

This research effort has focused on analyzing the measurement error of direct detection wind lidar based on Fabry-Perot interferometer and propose corresponding methods to decrease the error. By analyzing the laser's generation, launch, frequency discrimination and inverting, methods are raised and proved by experiments.This thesis mainly focuses on the following works:First of all, backgrounds of this issue and research status is reviewed,in which the optimization schemes are stressed. By analyzing the schemes,a research view through signal processing is proposed.Then the fundamental theory of wind lidar is deduced and analyzed,including the lidar system structure and double edge algorithm.Analysis is applied to the laser and FPI by the consequence of lidar structure to find out the measure error that might result in and rise and prove the solutions by simulation and experiment:With the laser oscillation frequency formula, quantitative analysis on the influence of temperature and vibration is performed and to continuously track frequency drift, the process of frequency locking by 3 channel FPI is described.To restrain the Nd:YAG laser frequency drifting, a novel method to estimate transmission curve of Fabry-Perot interferometer is proposed. Simulation and experiments proves the method could narrow down the estimate error to 0.1%.Finally an analysis on wind retrieval methods for Mie Doppler lidar is described in which 4 different Doppler frequency response function are compared in sensitivity and measurement error. The results reveal the relationship between measurement error and Doppler shift, measurement error and splitting ratio and the condition to achieve the optimal sensitivity is proved.