The Discrimination Technique Of Single Longitudinal Mode Frequency Stabilized Laser Pulse Of Doppler Lidar

Accurate atmospheric wind field observations are important for improving the accuracy of long-term weather forecasts,military environmental forecasts,and improving national security.With the continuous development of space science,it is very important to detect the wind field in the range of 15?60km.In many detection methods,Doppler wind lidar with its high resolution,high precision,large detection range,the ability to provide three-dimensional wind field information ability,has aroused the concern of scholars at home and abroad,and put a lot of manpower and material resources to carry out research.In the second chapter,the principle of seed injection laser and the principle of Doppler wind lidar are introduced,And then leads to the study of single longitudinal mode frequency stabilization laser pulse discrimination method.The third chapter is mainly to introduce the design of a pulse screening circuit witch is to solve the problem that when the seed laser injection is not successful,the multi-longitudinal mode output will affect the accuracy of wind detection.Firstly,the influence of the laser pulse on the wind speed measurement is analyzed.The wind speed sensitivity will be two order of magnitude between the seed is injected and the seed is not injected..If the seed is not successfully injected,the Q-pulse will have a long setup time.If the seed is successfully injected,the Q-pulse will have a smaller setup time.The pulse-screening circuit is used to determine the seed injection by detecting the change of the laser pulse in the time domain.Successful injection of laser pulses.Through the design of the pulse count card and the corresponding host computer software statistics seed number of successful pulse injection.The fourth chapter of the paper introduces the pulse detection experiment.Pulse filter circuit combined with three lasers for experiments.The three lasers can effectively reduce the wind error for about 0.29m/s,3.25m/S and 0.25 m/s when the wind speed is 100m/s by using the screening circuit eliminate the unseeded pulse.