不同近远场外推方案对MRTD散射模型穆勒矩阵计算精度的影响分析

Influence Analysis of Near-to-Far Field Transformation Schemes on Mueller Matrix Calculation Accuracy of MRTD Scattering Model

非球形气溶胶穆勒散射矩阵的不确定性是影响偏振遥感精度的重要因素。在自主研制的时域多分辨率(MRTD)气溶胶散射模型中,穆勒散射矩阵的计算需要以远场电场值为基础,因此近远场外推过程成为制约其模拟精度的重要环节。为确定适用于MRTD散射模型的最佳近远场外推方案,在球形和非球形粒子情形下,系统地对比分析了基于惠更斯原理的表面积分方案以及基于电介质亥姆霍兹方程的体积积分方案所对应的穆勒散射矩阵的模拟精度。结果表明,虽然两种近远场外推方案均可有效准确地实现近远场外推,但从穆勒矩阵的计算误差分布上看,基于体积积分原理的近远场外推方案性能更优。

The uncertainty of the Mueller scattering matrix of nonspherical aerosol is a significant factor influencing the accuracy of polarization sensing.In the self-developed multi-resolution time-domain（MRTD）aerosol scattering model,the Mueller scattering matrix should be calculated from the electric field in far region.Therefore,the nearto-far field transformation process becomes an important step influencing its simulation accuracy.In order to determine the best near-to-far field transformation scheme for MRTD scattering model,the simulation accuracy of the Mueller scattering matrix corresponding to the surface integration scheme based on Huygens principle and the volume integration scheme based on Helmholtz equations for dielectric medium is compared and analyzed systematically in the case of spherical and nonspherical particles.The results show that,although both of the nearto-far field transformation schemes can achieve near-to-far field transformation effectively and accurately,the nearto-far field transformation scheme based on volume integration principle has better performance based on the calculation error distribution of the Mueller matrix.