机载激光距离选通成像大气后向散射光强研究

Study on Back-Scattering Light Intensity in Airborne Laser Range-Gated Imaging

结合距离选通技术在机载激光主动成像中的应用,对距离选通模型参数的时序关系进行了分析,得出了大气后向散射范围和单位截面的脉冲前点和后点时刻;给出了大气后向散射光强计算方法,并对机载激光主动成像斜程探测距离进行了修正;利用散射截面上点的物像关系,建立了探测成像系统光路图,给出了散射截面反射点与增强电荷耦合器(ICCD)探测器面接收点位置光强的对应关系;通过数字仿真分别得到水平和斜程探测器面光强的变化规律,以及像面上的光强分布情况;搭建了外场实验平台,得到实测结果与仿真结果的数据相对误差基本控制在5%以内,具有很好的符合程度,实测结果验证了所建模型的实效性。

Based on the application of range-gated technology in the airborne laser detection imaging system, temporal relations of the parameters in the model of range gating are analyzed in detail and effective scope of atmospheric backscatter and the before- and after- pulse points of the unit section are obtained. A horizontal range-gated imaging model is established and the calculation method of back-scattering light intensity is given, and then tilt detection distance of airborne laser active imaging is revised. Based on the object-image relation of points on the scattering section, the light path diagram of detecting imaging system is built and the corresponding relationship of light intensity between scattering points and receiving points is provided. The variation regularity and distribution of light intensity on the detector under horizontal and tilt detection are gained. An outfield test platform is set up, and the relative error between measured data and simulation results is controlled within five percent, the measured data are consistent with the simulation results to a higher degree, which demonstrates the effectiveness of the built model.