双激光束的非多普勒激光雷达测风系统研究

Research on non-Doppler lidar wind measurement system with dual laser beams

摘要:

为设计一种低成本、高精度、可遥测的风速测量装置,基于米散射理论和泰勒冻结假设,提出了一种双激光束的非多普勒激光雷达测风系统。设计了以532 nm激光器为光发射单元,电荷耦 合 器件(charge-coupled device,CCD)为光接收单元,计算机为信息处理单元的非多普勒激光雷达测风实验装置。在风速为3 m/s和2 m/s的条件下,双激光束的前向散射回波信号分别生成了左、右两束激光的光强图；对光强图进行处 理,获得了气溶胶从一束激光运动到另一束激光所需的时间。结合两激光束的间距,在风速3 m/s和2 m/s的条件下,获得了风速测量值,平均测量值与实际值的误差分别为7%和7.33%。非多普勒激光雷达测风系统设计简易、成本低廉,具有很强的现实意义。

Abstract:

On the basis of Mie scattering theory and Taylor′s frozen hypothesis,a dual laser non-Doppler lidar wind measurement system is developed in order to design a low-cost,high-precision,telemetered wind speed measurement device.A 532 nm laser is used as the light-emitting unit,a charge-coupled device (CCD) as the light-receiving unit,and a computer as the information processing unit in the design of the experimental non-Doppler lidar wind measurement device.Under conditions of 3 m/s and 2 m/s wind speed,the foward scattered echo signals of the dual laser beams produce the light intensity maps of the left and right lasers,respectively.After analyzing the light intensity map,it is possible to calculate how long it would take for an aerosol to migrate from one laser beam to another.Using the distance between the two laser beams,the wind speed measurements are obtained under the conditions of wind speeds of 3 m/s and 2 m/s.The errors are 7% and 7.33%,respectively,between the mean measured value and the actual value.The non-Doppler lidar wind measurement device is simple in design,affordable,and has a significant practical application.