近距离雾的激光多次散射模拟

为了满足精确快速获取雾的多次散射仿真需求,在近程雷达距离较近情况下,将雷达方程和Mie散射理论相结合,提出一种快速有效的激光多次散射计算方法.首先通过雾滴谱模型建立雾颗粒的几何模型,然后根据Mie散射理论获得的单个粒子的散射函数计算激光在雾模型中单个颗粒的一次散射和二次散射功率密度,结合雷达方程推导出雾的多次等效散射截面和散射系数计算函数.模拟计算表明:雾的激光二次等效散射截面与雾浓度的2/3次方成正比,二次散射系数随能见度增加的衰减比一次散射系数快.

Laser Multiple Scattering Simulation for Fog with Closed Distance

In order to meet the demand for accurate and rapid multiple scattering simulation of fog,when the short-range radar distance was close,a fast and efficient simulation method of multi-scattering was proposed based on the combination of Mie theory and radar equation.First,the fog model was built according to the fog particle size distribution.Then,scattering functions about single particle were given based on Mie theory,and the first order scattering and the second order scattering power densities of single particle in fog model were calculated.The expressions of multiple scattering cross section of single particle and scattering coefficients of fog were deduced based on radar equation.Simulation results show that the second order scattering cross section is approximately proportional to 2/3 power density of fog,and the second order scattering coefficient with increasing visibility decreases more quickly than the first order scattering.