極化干涉SAR植被高度反演算法研究
本文選題:極化干涉SAR + 散射相位 ; 參考:《中南大學(xué)》2013年碩士論文
【摘要】:極化干涉SAR是一門結(jié)合極化SAR和干涉SAR優(yōu)點(diǎn)的新興技術(shù),既能獲得觀測(cè)目標(biāo)的精細(xì)物理特征和紋理特征,又能夠反映觀測(cè)目標(biāo)的空間分布特性。通過極化散射矩陣分解技術(shù)在分辨單元內(nèi)實(shí)現(xiàn)多種散射機(jī)制相位中心分離,為植被覆蓋下的地表地形測(cè)量和植被高度估計(jì)提供了可能。因此,極化干涉SAR技術(shù)可被用于植被參數(shù)反演,對(duì)地面資源和生態(tài)環(huán)境的監(jiān)測(cè)有著重要的意義。 本文對(duì)極化干涉SAR相關(guān)理論和極化干涉SAR植被高度反演算法進(jìn)行了研究,主要工作和創(chuàng)新點(diǎn)如下: (1)深入分析了兩種典型極化干涉SAR散射相位中心估計(jì)方法。由于極化干涉SAR散射相位中心估計(jì)算法是植被高度反演的關(guān)鍵步驟,于是本文深入研究了基于ESPRIT算法的極化干涉SAR散射相位中心估計(jì)算法和基于Freeman-極化干涉SAR互協(xié)方差矩陣分解的相位中心估計(jì)算法,并通過模擬和真實(shí)極化干涉SAR數(shù)據(jù)驗(yàn)證算法的性能。實(shí)驗(yàn)結(jié)果發(fā)現(xiàn):基于ESPRIT相位估計(jì)算法能較好地估計(jì)出植被冠層頂部相位中心,但是難以有效估計(jì)出地面散射相位中心;而基于Freeman-極化干涉SAR互協(xié)方差矩陣分解的相位中心估計(jì)算法能夠較好地估計(jì)出地面散射相位。 (2)結(jié)合ESPRIT相位中心估計(jì)算法及Freeman-極化干涉互協(xié)方差矩陣分解的相位中心估計(jì)算法的優(yōu)點(diǎn),提出了一種改進(jìn)的ESPRIT的植被高度反演算法。該算法解決了傳統(tǒng)ESPRIT植被高度算法中估計(jì)的地面散射相位不準(zhǔn)確這一問題。通過選取模擬和真實(shí)極化干涉SAR數(shù)據(jù)進(jìn)行實(shí)驗(yàn),驗(yàn)證了改進(jìn)的算法較之傳統(tǒng)的方法能夠獲得更高的反演精度。 (3)提出了一種結(jié)合Freeman-極化干涉互協(xié)方差矩陣分解及RVOG模型的植被高度反演算法。該算法將Freeman-極化干涉分解估算的地面散射相位作為RVOG模型的初始地表相位,然后利用RVOG模型進(jìn)行植被高度反演。利用模擬和真實(shí)的極化干涉SAR數(shù)據(jù)進(jìn)行實(shí)驗(yàn),驗(yàn)證了該算法的有效性,結(jié)果表明該方法可以獲得更高的植被高度反演精度。圖:55幅,表:6個(gè),參考文獻(xiàn):52篇。
[Abstract]:Polarimetric interference (SAR) is a new technology which combines the advantages of polarized SAR and interference SAR. It can not only obtain the fine physical and texture features of the observed target, but also reflect the spatial distribution of the observed target. The polarimetric scattering matrix decomposition technique is used to separate the phase centers of various scattering mechanisms in the resolution unit, which makes it possible to measure the surface topography and estimate the height of vegetation under vegetation cover. Therefore, polarimetric interferometry (SAR) can be used to invert vegetation parameters, which is of great significance to the monitoring of surface resources and ecological environment. In this paper, the correlation theory of polarimetric interferometry (SAR) and the vegetation height inversion algorithm of polarimetric interferometry (SAR) are studied. The main work and innovations are as follows: 1) two typical polarimetric interferometric SAR scattering phase center estimation methods are analyzed. Because the phase center estimation algorithm of polarization interference SAR scattering is a key step in vegetation height inversion. In this paper, the phase center estimation algorithm of polarimetric interference SAR scattering based on ESPRIT algorithm and the phase center estimation algorithm based on Freeman-polarization interference SAR cross-covariance matrix decomposition are studied. The performance of the algorithm is verified by simulation and real polarization interference SAR data. The experimental results show that the ESPRIT phase estimation algorithm can estimate the top phase center of the vegetation canopy, but it is difficult to estimate the surface scattering phase center effectively. The phase center estimation algorithm based on Freeman-polarization interferometric SAR cross-covariance matrix decomposition can estimate the surface scattering phase well. Combining the advantages of the ESPRIT phase center estimation algorithm and the phase center estimation algorithm based on Freeman-polarization interference covariance matrix decomposition, an improved vegetation height inversion algorithm for ESPRIT is proposed. The algorithm solves the problem of inaccurate ground scattering phase estimation in the traditional ESPRIT vegetation height algorithm. By selecting simulated and real polarimetric interferometric SAR data, it is verified that the improved algorithm can obtain higher inversion accuracy than the traditional method. A vegetation height inversion algorithm based on Freeman-polarization interference covariance matrix decomposition and RVOG model is proposed. The ground scattering phase estimated by Freeman-polarization interferometric decomposition is taken as the initial surface phase of RVOG model, and then vegetation height inversion is carried out by using RVOG model. The validity of the proposed algorithm is verified by simulation and real polarimetric interferometric SAR data. The results show that the proposed method can obtain higher accuracy of vegetation height inversion. Figs. 55, tables: 6, references: 52.
【學(xué)位授予單位】:中南大學(xué)
【學(xué)位級(jí)別】:碩士
【學(xué)位授予年份】:2013
【分類號(hào)】:TN957.52;P23
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 楊磊;趙擁軍;王志剛;;基于功率和相位聯(lián)合估計(jì)TLS-ESPRIT算法的極化干涉SAR數(shù)據(jù)分析[J];測(cè)繪學(xué)報(bào);2007年02期
2 談璐璐;楊立波;楊汝良;;基于ESPRIT算法的極化干涉SAR植被高度反演研究[J];測(cè)繪學(xué)報(bào);2011年03期
3 陳兵;徐紹劍;張平;;單基線PolInSAR反演算法研究[J];電子與信息學(xué)報(bào);2008年07期
4 陳曦;張紅;王超;;雙基線極化干涉合成孔徑雷達(dá)的植被參數(shù)提取[J];電子與信息學(xué)報(bào);2008年12期
5 李廷偉;黃海風(fēng);梁甸農(nóng);朱炬波;;基于Freeman分解的植被參數(shù)反演新方法[J];電子與信息學(xué)報(bào);2011年04期
6 李廷偉;梁甸農(nóng);黃海風(fēng);朱炬波;;一種基于BP神經(jīng)網(wǎng)絡(luò)的極化干涉SAR植被高度反演方法[J];國(guó)防科技大學(xué)學(xué)報(bào);2010年03期
7 陳爾學(xué);李增元;龐勇;田昕;;基于極化合成孔徑雷達(dá)干涉測(cè)量的平均樹高提取技術(shù)[J];林業(yè)科學(xué);2007年04期
8 于大洋,董貴威,楊健,彭應(yīng)寧,王超,張紅;基于干涉極化SAR數(shù)據(jù)的森林樹高反演[J];清華大學(xué)學(xué)報(bào)(自然科學(xué)版);2005年03期
9 談璐璐;陳兵;楊汝良;;利用POLInSAR數(shù)據(jù)反演植被高度的改進(jìn)三階段算法[J];系統(tǒng)仿真學(xué)報(bào);2010年04期
10 楊震,楊汝良;極化合成孔徑雷達(dá)干涉技術(shù)[J];遙感技術(shù)與應(yīng)用;2001年03期
,本文編號(hào):1813217
本文鏈接:http://sikaile.net/kejilunwen/dizhicehuilunwen/1813217.html