基于模型的星载PolSAR海冰自适应极化分解法  

Model-based Sea Ice Adaptive Polarimetric Decomposition Method for Spaceborne PolSAR

作　　者：陆禾 申梦雨 田忠 LU He;SHEN Mengyu;TIAN Zhong(Shanghai Radio Equipment Research Institute,Shanghai 201109,China;Unit 95696 of People’s Liberation Army of China,Chongqing 400050,China)

机构地区：[1]上海无线电设备研究所,上海201109 [2]中国人民解放军95696部队,重庆400050

出　　处：《制导与引信》2024年第2期50-60,共11页Guidance & Fuze

摘　　要：提出了基于模型的星载PolSAR海冰自适应极化分解法,该算法涉及体散射分量自适应分解以及表面、二面散射分量自适应分解两方面。在体散射自适应分解方面,推导了体散射功率的解析表达式从而实现了对极化信息的完整利用,构建了完全覆盖海冰粒子水平、垂直和随机定向的三个体散射模型,并采用基于最大功率拟合的自适应模型选择策略,解决了当前海冰极化分解法无法根据冰层中夹杂的盐水包裹体构成的粒子云的定向方式自适应匹配体散射模型的问题。在表面和二面散射自适应分解方面,将标准Huynen二分法用于对体散射分解后的剩余相干矩阵的降秩分解,根据实际冰面的散射机制自适应选取分解方法,提取了表面散射和二面散射功率信息,在实现极化散射信息完整利用的同时保证分解结果不会退化。基于高分三号(GF-3)卫星全极化合成孔径雷达获取的南极洲普利兹湾海冰数据开展了体散射模型和分解算法的有效性验证。体散射分量的分解结果首次从极化分解角度揭示了冰层中盐水包裹体以垂直定向为主导、同时存在次级随机定向以及不可忽视的水平定向的定向特征。A model-based sea ice adaptive polarimetric decomposition method for spaceborne PolSAR was proposed,which involved the adaptive decomposition of volume scattering component,the adaptive decomposition of surface and double-bounce scattering components.On the adaptive decomposition of sea ice volume scattering,in order to make full use of the polarimetric scattering information,the analytic expression of volume scattering power was analytically obtained.The three volume scattering models constructed could perfectly provide a complete coverage of the horizontal tilt,vertical tilt and random tilt of sea ice particles.Hence,the adaptive model selection strategy was developed,which was based on the maximum power fitting,so as to solve the problem of the existing model-based sea ice decomposition methods that could not adaptively match the volume scattering models according to the orientation of the sea ice particle cloud,which was composed of elliptical brine inclusions mixed in the sea ice.On the adaptive decomposition of surface and double-bounce scattering,the canonical Huynen dichotomy was used for rank-reduction decomposition of the residual coherency matrix after decomposing the volume component,and adaptively selected the decomposition method and extracted the surface and double-bounce scattering components according to the actual scattering mechanism of sea ice surface to achieve the complete utilization of the polarimetric scattering information while ensuring the decomposition results not degenerate to the dichotomous results.The effectiveness of modeling and decomposition was finally verified on the basis of the Gaofen-3 PolSAR data of sea ice in Prydz Bay,Antarctica.The decomposition results of the volume scattering component reveal the dominant vertical tilt,secondary random tilt and non-negligible horizontal tilt of brine inclusions in sea ice from the viewpoint of polarimetric decomposition for the first time.

关 键 词：全极化合成孔径雷达 自适应极化分解 海冰 

分 类 号：TN957.52[电子电信—信号与信息处理]