各向异性散射介质中高斯脉冲激光的回波特性

Echo Characteristic of Gaussian Pulse Laser in Anisotropic Scattering Medium

采用蒙特卡罗法建立了各向异性散射介质中高斯脉冲激光的全链路瞬态辐射传输模型,构造并推导了散射方向概率模型及其坐标系变换过程。在此基础上,计算分析了高斯脉冲激光回波特性的时域分布及差异。研究结果表明:时域回波信号的脉冲增减来自于其他类别信号的转化和自身信号的超前或滞后;随着前向散射的增强,目标回波信号强度增大、峰值时刻前移、时间展宽减弱,散射回波信号响应与其相反且影响程度减弱;目标回波特性与[0°,90°]前向散射区域直接关联,散射回波特性与[90°,180°]后向散射区域直接关联。研究结论可为脉冲激光主动探测系统的性能提升及地物目标的反探测隐身提供理论指导。

The whole-process transient radiative transfer model of Gaussian pulse laser in anisotropic scattering medium is established using Monte Carlo method, then the probabilistic model of scattering direction is constructed and the process of coordinate system transformation is deduced. On the basis above, the temporal distribution and differences of Gaussian pulse laser echo characteristic is calculated and analyzed. Research result shows that pulsed increase/decrease of temporal echo signal is from the conversion of other signal categories and ahead or lag of itself;with the forward scattering enhancing, target-echo signal intensity increases, peak time forwards and temporal broadening weakens, while scatter- echo signal responses are in contrast and change weakly; target- echo characteristic associates with [0°, 90°] forward scattering region directly, as well as scatter-echo characteristic associating with [90°, 180°] backward scattering region. The conclusion can provide theoretical guidance for performance improvement of active detection systems by pulse laser and anti-stealth detection of ground objects.