脉冲激光引信烟尘环境回波模拟计算方法

Simulation method of pulse laser fuze echo in dust environment

针对常用Henyey-Greenstein散射相函数(H-G散射相函数)在描述单个粒子前向及后向散射特性时的不准确性,提出将基于T矩阵法的散射相函数用于激光烟尘散射研究的方法。通过T矩阵法计算烟尘粒子单次散射特性,并提出基于离散散射相函数的散射角抽样方法,利用随机数描述多重散射的散射分布,结合光子的半解析接收方法,建立了激光引信在烟尘环境下发射及接收的理论模型。为验证理论模型的正确性,通过封闭烟尘环境实验室,对激光引信在实际烟尘环境下的接收能力进行测试,分析不同烟尘浓度及湿度条件对回波的影响,并与采用H-G散射相函数理论模型的计算结果进行对比。结果表明,随着烟尘浓度和湿度的增加,激光回波幅度也相应增大,且基于T矩阵散射相函数的回波仿真方法与实验结果更吻合,尤其是烟尘浓度较大的情况,实验与理论分析结果一致。

Since the most widely used single-scattering phase function—Henyey-Greenstein scattering phase function(H-G scattering phase function)cannot reproduce the forward scattering and backscattering behavior well,a method based on the T-matrix scattering phase function was proposed to analyze and simulate the multiple scattering and echo signal of the pulse laser in the dust environments.The single-scattering properties of dust particles were calculated by the T-matrix method and a sample method was proposed to apply T-matrix scattering phase function to the Monte Carlo simulation with a random number.Furthermore,the theoretical model of the transmission and reception of a laser fuze in dust environments was built with the above sample method and semianalytic sensing geometric method of a photon.To verify the precision of the theoretical model,a dust environment laboratory was designed and built to evaluate the performance of laser fuzes in different dust environments.Therefore some experiments were completed to derive the echo amplitudes of a laser fuze in the dust environments with different dust concentrations and the results were compared with corresponding simulation results of H-G scattering phase function and T-matrix method.The simulation results show that echo powers are increased with the increase of dust concentrations and relative humidity.And the method based on Tmatrix scattering phase function has a better consistency with the experiment and is more stable,especially in denser dust environments.