基于多普勒测风激光雷达的锁频系统与激光测速系统的设计与实现

在非相干多普勒测风激光雷达系统中,激光的线宽与频率的稳定性是影响测量结果准确性的两个重要因素。研制的激光雷达系统采用种子注入方法产生窄线宽脉冲激光,采用碘分子饱和吸收稳频的方法,利用VB语言基于PID算法编写仪器控制程序,将种子激光器的频率锁定在碘分子吸收线1 109线的高波数边缘上,长时间(4 h)锁频的精度0.5 MHz,频率的长期稳定度为3.5510-9。设计了连续光测速系统,得出多普勒频移测得的实验值与实际斩波盘的速度值曲线,速度误差小于0.4 m/s。由此也说明,所设计的连续光测速系统可以对整个锁频系统进行校准。该实验也为测风激光雷达的建设提供指导意义。

Design and realization of frequency locking system and laser velocity measuring system based on Doppler wind lidar

In the noncoherent Doppler wind lidar system, the laser line width and frequency stability are two important factors influencing the accuracy of measurement results. The injection seeding technique method was used to obtain narrow linewidth of 532 nm lidar. The iodine filters as receiv frequency discriminators and lock the transmitter laser frequency. Using VB language writing instrument control program based on PID algorithm, the frequency of seed laser locked in iodine molecular absorption lines, which was 1 109 line of high reflection on the edge. The frequency stability was better then 0.5 MHz for 4 h, the long-term frequency stability as 3.5510-9. Design the continuous light velocity measuring system, which concluded the cure about Doppler frequency shift and actual speed of chopped wave plate, the velocity error was less than 0.4 m/s. This also shows that the laser velocity measuring system can be calibrated on the lock the frequency of the whole system. This experiment also provides guidance significance for the construction of wind lidar.