强激光与粒子束2026，Vol.38Issue(2)：65-72,8.DOI:10.11884/HPLPB202638.250261
毫米波非球形冰晶粒子双偏振散射特性研究
Study on dual-polarization scattering characteristics of millimeter-wave nonspherical ice crystals
摘要
Abstract
[Background]Traditional Mie theory,assuming spherical particles,is inadequate for characterizing the scattering of atmospheric non-spherical ice crystals.Existing studies are largely limited to single frequency(e.g.,94 GHz),lacking systematic quantification of key dual-polarization parameters across the millimeter/submillimeter wave spectrum,which constrains the accuracy of the polarimetric radar for meteorological target detection and classification.[Purpose]This study aims to systematically investigate the dual-polarization scattering properties of six typical non-spherical ice crystals—hexagonal columns,plates,hollow columns,bullet rosettes,aggregates,and supercooled water droplets—across 35,94,140,and 220 GHz bands.It quantifies the responses of differential reflectivity(ZDR)and linear depolarization ratio(LDR)to particle shape and orientation,providing crucial theoretical support for wideband polarimetric radar meteorology.[Methods]Scattering models were developed using the Discrete Dipole Approximation(DDA)and Finite-Difference Time-Domain(FDTD)methods,cross-validated with commercial software(XFDTD,HFSS).Backscattering cross-sections,ZDR,and LDR were computed for different ice crystals across the frequency bands,analyzing the influence of particle size,geometry,and frequency.[Results]1)The reliability of DDA was systematically validated across the 35-220 GHz range.Calculation errors for backscattering cross-sections were≤1.5 dB for all particles except highly random aggregates.2)Radar reflectivity factor showed a coupled wavelength dependence:small particles(equivalent radius＜100 μm)were wavelength-insensitive(＜1 dB difference),while large particles(>100 μm)exhibited significant shape-dependent resonance.The equivalent radius corresponding to resonance extrema increased with wavelength.3)Characteristic ranges of ZDR and LDR for the six ice crystal types were quantified.Hexagonal plates showed the widest ZDR range(9 dB to-9 dB),while axisymmetric particles exhibited stable LDR values(-40 dB to-50 dB).[Conclusions]This wideband,multi-particle study addresses prior limitations in frequency coverage and parameter quantification.It demonstrates that the shape-sensitive ZDR and LDR parameters can reduce dependence on particle size distribution and significantly improve ice crystal identification accuracy,providing a key theoretical basis for millimeter/submillimeter wave polarimetric radar applications in cloud microphysics and meteorological target classification.关键词
非球形冰晶粒子/双偏振散射/离散偶极子近似/毫米波/差分反射率因子Key words
non-spherical ice crystals/dual-polarization scattering/discrete dipole approximation/millimeter wave/differential reflectivity分类
信息技术与安全科学引用本文复制引用
王金虎,孙孟奇,严逸帆,武宸宇..毫米波非球形冰晶粒子双偏振散射特性研究[J].强激光与粒子束,2026,38(2):65-72,8.基金项目
国家自然科学基金项目(41905026) （41905026）
江苏省自然科学基金项目(NBK20170945) （NBK20170945）
南京信息工程大学人才启动基金项目(2016r028) （2016r028）
中国博士后科学基金第63批面上课题(2018M631554) （2018M631554）
江苏省333高层次人才培养工程资助项目 （）
江苏省高等教育教改立项研究课题(2023JSJG330) （2023JSJG330）
