运动目标激光图像获取及后向散射抑制算法研究

摘要

Laser range-gated active imaging under atmospheric conditions for stationary target imaging has the advan-tages of high resolution,long-range,etc.For moving target imaging,in order to track the moving targets,the distance gate width should increase,and then cause backscattering.The active imaging system based on laser range-gated is analyzed,and the range information is introduced to track moving target in real time on this basis.The effect of back-ward scattering caused by different gate width on image quality is studied.The lifting wavelet transform is adopted to introduce homomorphic filtering,and the noise caused by the backward scattering is as the low frequency components, and then the wavelet coefficients are processed by using high-pass filtering.The results show that,the algorithm a-chieves good backward scattering suppression effect,and basically eliminates the backward scattering effect,which makes the backward scattering noise ratio of the whole image reduce from 66% to 1%.%基于距离选通的激光主动成像在大气条件下对静止目标成像时具有分辨率高、作用远距离等优点，但是对运动目标成像时，为了跟踪运动中的目标，距离选通门宽相应增加，进而引起后向散射。文中分析了基于距离选通的激光主动成像系统，在此基础上引入距离信息实时跟踪运动目标，研究了不同选通门宽引起的后向散射对图像质量的影响，提出采用提升小波变换引入同态滤波，将后向散射引起的噪声作为低频成分，利用高通滤波对小波变换系数进行处理。结果表明，提出的算法取得了良好的后向散射抑制效果，基本消除了后向散射的影响，将后向散射噪声在整幅图像中的比例由66％降低到1％以下。