極化目標(biāo)模型分解的不一致性研究
發(fā)布時(shí)間：2019-07-09 15:03
【摘要】：合成孔徑雷達(dá)(SAR)以其能穿透云霧、煙塵及大面積獲取地表信息和全天候全天時(shí)的特點(diǎn)越來(lái)越受到重視。全極化SAR (PoISAR)作為當(dāng)前最先進(jìn)的SAR系統(tǒng),較單極化所蘊(yùn)含的信息量豐富,且能揭示和描述目標(biāo)內(nèi)在的散射機(jī)理。由于全極化SAR系統(tǒng)特有的成像方式,使得獲取影像單一像素的散射實(shí)際由多種散射類型疊加而成。以極化目標(biāo)分解為代表的基于模型的非相干分解模型將散射矩陣分解為散射模型線性加權(quán)和的形式,能夠直觀地反映該過程,且分解出的散射分量對(duì)不同應(yīng)用中物理參數(shù)的分析或反演具有重要意義,是當(dāng)前研究的熱點(diǎn)。盡管如此,基于模型的極化目標(biāo)分解存在分解不一致現(xiàn)象,主要表現(xiàn)為分解后的散射分量功率為負(fù)值,嚴(yán)重阻礙了地物的分析與解譯。本文在充分理解模型分解的基礎(chǔ)上,分別對(duì)三分量和四分量分解中的不一致性問題進(jìn)行了詳細(xì)地探究,并發(fā)展了相應(yīng)的解決方法,最后將模型分解的極化特征應(yīng)用于建筑物的分割中。本文的主要研究成果如下： 1.基于全極化協(xié)方差矩陣詳細(xì)推導(dǎo)分析了三分量模型分解不一致產(chǎn)生的原因,發(fā)展了一種綜合去取向理論和廣義體散射模型的三分量極化目標(biāo)分解模型,首先在分解前對(duì)協(xié)方差矩陣進(jìn)行去取向處理以削弱交義極化分量；然后采用一種廣義體散射模型以適應(yīng)林地中HH分量和VV分量的比值變化；最后采用歸一化處理以完全消除負(fù)功率問題,該處理能夠保持地物主導(dǎo)散射類型不變。實(shí)驗(yàn)采用德國(guó)Oberpfaffenhofen地區(qū)L波段機(jī)載E-SAR數(shù)據(jù)進(jìn)行,并與其他改進(jìn)算法模型進(jìn)行比較,表明綜合處理后的分解模型不僅能夠消除不一致問題,且能夠有效地增強(qiáng)城區(qū)中的由二面角產(chǎn)生的偶次散射分量。 2.基于全極化協(xié)方差矩陣詳細(xì)推導(dǎo)分析了四分量模型分解不一致產(chǎn)生的原因,為解決該問題,提出了一種綜合四分量分解模型。首先,本文提出了一個(gè)新的復(fù)混合極化相關(guān)系數(shù)分別對(duì)地物目標(biāo)進(jìn)行選擇性去取向和螺旋體散射功率抑制。之后,為解決四分量體散射模型單一的問題,仍采用廣義體散射模型來(lái)替代原體散射模型。最后,為完全消除分解負(fù)功率像素,在歸一化處理方法的功率限制基礎(chǔ)上進(jìn)一步改進(jìn),該處理方法包含類似Krogager相干分解的非相干分解。通過與其他改進(jìn)方法的比較,使用德國(guó)Oberpfaffenhofen地區(qū)機(jī)載L波段E-SAR數(shù)據(jù)驗(yàn)證了該綜合四分量分解模型的有效性,并使用德國(guó)普拉特靈地區(qū)的全極化星載X波段的TerraSAR數(shù)據(jù)探討了對(duì)短波全極化SAR影像的適用性。 3.針對(duì)傳統(tǒng)全極化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種綜合多種極化特征和幾何特征的全極化SAR建筑物分割模型,該模型通過改進(jìn)分形網(wǎng)絡(luò)演化算法和使用多元線性回歸模型,構(gòu)建綜合多特征的建筑物分割模型,通過與傳統(tǒng)H-Alpha-Wishart等分割方法進(jìn)行比較,驗(yàn)證了該綜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，
本文編號(hào)：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，
本文編號(hào)：2512230
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