Simulation Research of Coherent Lidar Based on Golay Coding Technology

Abstract

Aiming at the low signal-to-noise ratio (SNR) of coherent lidar echo signal in the far field, a method using pulse coding to coherent wind lidar is proposed to improve the SNR and dynamic range of the system. The encoding and decoding principle of Golay code in coherent lidar system is introduced. The improvement of SNR of the system by using pulse coding technology is analyzed in theory. Based on the atmospheric slices model, the echo signal of coherent Doppler lidar is simulated. Based on the decoding principle, the wind velocity with the pulse coding system is obtained. The simulation results show that, when the Golay code pulse is used as the detection pulse of the coherent lidar, the wind velocity error is less than 3m/s in the range of 0~5.3km with the distance resolution of 60m and the time resolution of 1s. In the same measurement time, the detection distance is improved by 2.5km compared with the traditional pulse coherent lidar, which improves the SNR of the far-field weak signal.