激光器重复频率对多普勒激光雷达信噪比影响的模拟研究

多普勒激光雷达在风场测量和数值天气预报等方面有重要意义,而信噪比则是衡量系统测量精度的重要参数.以2007年中国海洋大学研制的我国第一台车载多普勒测风激光雷达系统为参考,模拟了在相同平均功率下,使用4种重复频率不同的激光器的激光雷达系统测量海面风场中的信噪比,并与汕尾测量的海面风场数据进行了对比,模拟数据和实测数据能够较好吻合,模拟结果证明使用低重复频率激光器的激光雷达系统能够获得较高的信噪比.而根据多普勒激光雷达业务测量要求,要求比较高的激光重复频率,通过模拟研究,建议选择激光器激光重复频率500～1000 Hz.

Simulation of SNR of Doppler Lidar in Different Laser Repetition Rate

Doppler lidar plays an important role in wind measurements and numerical weather prediction, and signal to noise ratio(SNR) is an important parameter to measure the system’s accuracy.Based on the first mobile Doppler lidar system in China which is developed by Ocean University of China in 2007,the SNR for sea surface wind measurements with four different repetition rates are simulated.Simulated and measured data are in good agreement.The results show that the lower laser frequency used in the lidar,the higher SNR obtained.According to the requirements for operational measurements,Doppler lidar requires relatively high laser repetition rate.It is recommended to select a laser with pulse repetition rate during 500～1000 Hz.