Performance Optimization and Experimental Research of Continuous Wave Coherent Wind Lidar

Based on the requirement of wind velocity measurement, an all-fiber doppler coherent wind lidar system is built with continuous wave laser source at band 1 550 nm. It is analyzed theoretically for the Carrier-to-noise ratio function of the continuous wave coherent lidar and the weighing function of the wind velocity at different focusing distance on the basis of the lidar equation. A vari-focusing optical antenna with the focusing distance range from 5 m to 200 m is designed and fabricated according to the requirement of wind detection. The optical beam expanding module adopts the Galilean refractive structure with the beam expanding ratio as 23 and the optical quality is close to the diffraction limit. The calibration test is executed by using a rotating motor disk. The rotation speed range of the disk is from -3 000 r/min to +3 000 r/min. The diameter of the disk is 26 cm. While the doppler frequency shift of the line of sight velocity is positive and negative,the correlation coefficients between the velocity measurement data of the lidar system and the theoretical calculation result are 0.998 and 0.993. At the same time the standard deviations of velocity are 0.151 m/s and 0.229 m/s, respectively. The wind lidar is then used to measure the atmospheric wind speed. It works correctly to apply the wind lidar to measure the atmospheric wind velocity.