极化目标模型分解的不一致性研究
发布时间：2019-07-09 15:03
【摘要】：合成孔径雷达(SAR)以其能穿透云雾、烟尘及大面积获取地表信息和全天候全天时的特点越来越受到重视。全极化SAR (PoISAR)作为当前最先进的SAR系统,较单极化所蕴含的信息量丰富,且能揭示和描述目标内在的散射机理。由于全极化SAR系统特有的成像方式,使得获取影像单一像素的散射实际由多种散射类型叠加而成。以极化目标分解为代表的基于模型的非相干分解模型将散射矩阵分解为散射模型线性加权和的形式,能够直观地反映该过程,且分解出的散射分量对不同应用中物理参数的分析或反演具有重要意义,是当前研究的热点。尽管如此,基于模型的极化目标分解存在分解不一致现象,主要表现为分解后的散射分量功率为负值,严重阻碍了地物的分析与解译。本文在充分理解模型分解的基础上,分别对三分量和四分量分解中的不一致性问题进行了详细地探究,并发展了相应的解决方法,最后将模型分解的极化特征应用于建筑物的分割中。本文的主要研究成果如下： 1.基于全极化协方差矩阵详细推导分析了三分量模型分解不一致产生的原因,发展了一种综合去取向理论和广义体散射模型的三分量极化目标分解模型,首先在分解前对协方差矩阵进行去取向处理以削弱交义极化分量；然后采用一种广义体散射模型以适应林地中HH分量和VV分量的比值变化；最后采用归一化处理以完全消除负功率问题,该处理能够保持地物主导散射类型不变。实验采用德国Oberpfaffenhofen地区L波段机载E-SAR数据进行,并与其他改进算法模型进行比较,表明综合处理后的分解模型不仅能够消除不一致问题,且能够有效地增强城区中的由二面角产生的偶次散射分量。 2.基于全极化协方差矩阵详细推导分析了四分量模型分解不一致产生的原因,为解决该问题,提出了一种综合四分量分解模型。首先,本文提出了一个新的复混合极化相关系数分别对地物目标进行选择性去取向和螺旋体散射功率抑制。之后,为解决四分量体散射模型单一的问题,仍采用广义体散射模型来替代原体散射模型。最后,为完全消除分解负功率像素,在归一化处理方法的功率限制基础上进一步改进,该处理方法包含类似Krogager相干分解的非相干分解。通过与其他改进方法的比较,使用德国Oberpfaffenhofen地区机载L波段E-SAR数据验证了该综合四分量分解模型的有效性,并使用德国普拉特灵地区的全极化星载X波段的TerraSAR数据探讨了对短波全极化SAR影像的适用性。 3.针对传统全极化SAR影像分割的缺陷,并融合模型分解后的偶次散射分量提出了一种综合多种极化特征和几何特征的全极化SAR建筑物分割模型,该模型通过改进分形网络演化算法和使用多元线性回归模型,构建综合多特征的建筑物分割模型,通过与传统H-Alpha-Wishart等分割方法进行比较,验证了该综合分割模型的有效性。
[Abstract]:Synthetic Aperture Radar (SAR) has been paid more and more attention because of its ability to penetrate clouds, smoke and dust, to obtain surface information in a large area and to obtain all-weather and all-weather. As the most advanced SAR system, fully polarized SAR (PoISAR) is rich in information than unipolarization, and can reveal and describe the inherent scattering mechanism of the target. Because of the unique imaging mode of the fully polarized SAR system, the scattering of a single pixel of the image is actually superimposed by a variety of scattering types. The model-based incoherent decomposition model represented by polarimetric target decomposition decomposes the scattering matrix into the form of linear weighted sum of scattering model, which can reflect the process intuitively, and the decomposed scattering component is of great significance to the analysis or inversion of physical parameters in different applications, which is the focus of current research. However, there is a phenomenon of inconsistent decomposition of polarized targets based on the model, which is mainly manifested in that the power of scattering components after decomposition is negative, which seriously hinders the analysis and interpretation of ground objects. In this paper, on the basis of fully understanding the model decomposition, the inconsistency in three-component decomposition and four-component decomposition is discussed in detail, and the corresponding solutions are developed. finally, the polarization characteristics of model decomposition are applied to the segmentation of buildings. The main research results of this paper are as follows: 1. Based on the full polarization covariance matrix, the causes of the inconsistency in the decomposition of the three-component model are derived and analyzed in detail, and a three-component polarimetric target decomposition model based on the deorientation theory and the generalized body scattering model is developed. firstly, the covariance matrix is deoriented to weaken the intersecting polarization component, and then a generalized volume scattering model is used to adapt to the ratio change of the HH component and the VV component in the forest land. Finally, the normalization process is used to completely eliminate the negative power problem, which can keep the dominant scattering type of the ground object unchanged. The experiment is carried out by using L-band airborne E-SAR data in Oberpfaffenhofen area of Germany and compared with other improved algorithm models. It is shown that the decomposition model after comprehensive processing can not only eliminate the inconsistency problem, but also effectively enhance the even scattering components generated by dihedral angles in urban areas. two銆，
本文编号：2512230
[Abstract]:Synthetic Aperture Radar (SAR) has been paid more and more attention because of its ability to penetrate clouds, smoke and dust, to obtain surface information in a large area and to obtain all-weather and all-weather. As the most advanced SAR system, fully polarized SAR (PoISAR) is rich in information than unipolarization, and can reveal and describe the inherent scattering mechanism of the target. Because of the unique imaging mode of the fully polarized SAR system, the scattering of a single pixel of the image is actually superimposed by a variety of scattering types. The model-based incoherent decomposition model represented by polarimetric target decomposition decomposes the scattering matrix into the form of linear weighted sum of scattering model, which can reflect the process intuitively, and the decomposed scattering component is of great significance to the analysis or inversion of physical parameters in different applications, which is the focus of current research. However, there is a phenomenon of inconsistent decomposition of polarized targets based on the model, which is mainly manifested in that the power of scattering components after decomposition is negative, which seriously hinders the analysis and interpretation of ground objects. In this paper, on the basis of fully understanding the model decomposition, the inconsistency in three-component decomposition and four-component decomposition is discussed in detail, and the corresponding solutions are developed. finally, the polarization characteristics of model decomposition are applied to the segmentation of buildings. The main research results of this paper are as follows: 1. Based on the full polarization covariance matrix, the causes of the inconsistency in the decomposition of the three-component model are derived and analyzed in detail, and a three-component polarimetric target decomposition model based on the deorientation theory and the generalized body scattering model is developed. firstly, the covariance matrix is deoriented to weaken the intersecting polarization component, and then a generalized volume scattering model is used to adapt to the ratio change of the HH component and the VV component in the forest land. Finally, the normalization process is used to completely eliminate the negative power problem, which can keep the dominant scattering type of the ground object unchanged. The experiment is carried out by using L-band airborne E-SAR data in Oberpfaffenhofen area of Germany and compared with other improved algorithm models. It is shown that the decomposition model after comprehensive processing can not only eliminate the inconsistency problem, but also effectively enhance the even scattering components generated by dihedral angles in urban areas. two銆，
本文编号：2512230
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