主动照明激光对高精跟踪的影响分析

Effects on High-Precession Tracking on Active Illumination Laser

采用激光主动照明技术，是对远距离暗目标进行成像、定位和跟踪的重要手段。但由于激光在大气路径中传输，受到大气湍流等因素的影响会造成辐照在目标上的激光光强分布不均匀，同时激光波前会产生畸变，从而降低目标的成像质量，影响对目标的高精度跟踪能力。基于激光照明大气传输模型，对中等湍流、弱湍流和不同光束数情况下的激光照明结果进行了数值模拟，分析了照明激光光强和波前对远距离目标成像的影响。计算结果表明：照明光强起伏方差优于0．5，波前畸变标准误差优于0．2λ，可满足约1μrad量级的目标分辨能力。

Laser illumination is an effective technology for the imaging and tracking to the far dim targets in the air. Because of laser transmitting in the air, the spatial distribution of intensity on the target plane is non-uniform caused by atmospheric turbulence, and the laser wavefront generates aberration, which decreases image resolution and tracking accuracy in optical system. A model of illumination laser propagation in atmosphere has been built. Under the condition of moderate turbulence, weak turbulence and multi-beams, numeric simulation for laser illumination to air targets has been carried out, and the affects of illumination light intensity and wavefront on remote target imaging are analyzed. The results show that illumination light intensity fluctuation variance below 0. 5 and wavefront aberration standard error below 0.2 λ meet 1 μrad magnitude resolution capability.