寬帶雷達(dá)回波散射中心特征提取方法研究
發(fā)布時(shí)間:2018-06-12 15:08
本文選題:高分辨率 + 散射中心。 參考:《西安電子科技大學(xué)》2014年碩士論文
【摘要】:隨著理論研究的不斷深入和雷達(dá)信號(hào)分辨率的不斷提升,基于寬帶高分辨率雷達(dá)信號(hào)的目標(biāo)識(shí)別成為了雷達(dá)信號(hào)處理領(lǐng)域的一個(gè)重要發(fā)展方向。寬帶高分辨率雷達(dá)獲取的目標(biāo)回波不再是一個(gè)“點(diǎn)”,而是由一系列分布在不同距離單元上的目標(biāo)散射點(diǎn)構(gòu)成的高維信號(hào)。通過提取并分析目標(biāo)回波中的散射點(diǎn)可以獲取反映目標(biāo)本質(zhì)屬性的特征,如目標(biāo)體的物理尺寸以及典型部件的尺寸和結(jié)構(gòu)等信息。本文正是基于寬帶高分辨率雷達(dá)回波數(shù)據(jù),研究了目標(biāo)散射中心特征的提取方法。論文主要內(nèi)容概括如下:1.分析比較了四種稀疏求解算法,并引入交替投影法改進(jìn)算法。首先介紹了四種稀疏求解算法的基本原理和操作流程,結(jié)合實(shí)驗(yàn)比較了各個(gè)算法的應(yīng)用效果。然后提出了一種結(jié)合交替投影法的稀疏求解方法,通過不同的實(shí)驗(yàn)設(shè)置,驗(yàn)證了所提方法能夠提高稀疏求解的精度,并在一定程度上改善了求解算法對(duì)噪聲的穩(wěn)健性。2.研究了一維簡單散射中心特征的提取方法。介紹了一維散射中心的幾何繞射模型,以及極化散射矩陣的基本概念;提出了一種聯(lián)合多極化通道高分辨率距離像的散射中心提取方法。通過仿真實(shí)驗(yàn)證明,與傳統(tǒng)方法相比所提方法在目標(biāo)散射中心位置和極化散射矩陣的估計(jì)方面有一定優(yōu)勢。3.研究了屬性散射中心提取方法。(1)提出了一種結(jié)合交替投影與正交匹配追蹤的屬性散射中心提取方法。首先提取目標(biāo)的合成孔徑雷達(dá)(Synthetic Aperture Radar,SAR)圖像支撐區(qū)實(shí)現(xiàn)對(duì)目標(biāo)參數(shù)的自動(dòng)初始化,減少了字典維度,降低了計(jì)算復(fù)雜度;然后利用正交匹配追蹤法估計(jì)目標(biāo)屬性散射中心參數(shù),最后通過交替投影法對(duì)所估參數(shù)進(jìn)行修正。該方法能夠降低目標(biāo)屬性散射中心間的高度耦合對(duì)散射中心參數(shù)估計(jì)的影響,提高了估計(jì)精度。(2)提出了一種結(jié)合圖像信息的頻域?qū)傩陨⑸渲行奶卣魈崛》椒。該方法在頻域方法的估計(jì)過程中,引入目標(biāo)的圖像信息實(shí)現(xiàn)對(duì)散射中心間的去耦合,既降低了計(jì)算復(fù)雜度,也改善了參數(shù)估計(jì)精度。
[Abstract]:With the deepening of theoretical research and the improvement of radar signal resolution, target recognition based on wideband high resolution radar signal has become an important development direction in the field of radar signal processing. The target echo obtained by wideband high-resolution radar is no longer a "point", but a high-dimensional signal composed of a series of scattering points distributed on different distance units. By extracting and analyzing the scattering points in the echo of the target, the characteristics reflecting the essential properties of the target can be obtained, such as the physical size of the target body, the size and structure of the typical components, and so on. Based on the wideband high resolution radar echo data, this paper studies the extraction method of target scattering center feature. The main contents of this paper are summarized as follows: 1: 1. Four sparse solving algorithms are analyzed and compared, and the alternating projection method is introduced to improve the algorithm. Firstly, the basic principle and operation flow of four sparse solving algorithms are introduced, and the application results of each algorithm are compared with experiments. Then a sparse solution method combined with alternating projection method is proposed. Through different experimental settings, it is verified that the proposed method can improve the accuracy of sparse solution, and improve the robustness of the algorithm to noise to a certain extent. A method for extracting the feature of one-dimensional simple scattering center is studied. The geometric diffraction model of one-dimensional scattering center and the basic concept of polarimetric scattering matrix are introduced, and a method of extracting scattering center with high resolution range profile of multi-polarization channel is proposed. The simulation results show that the proposed method has some advantages over the traditional method in estimating the location of the target scattering center and the polarization scattering matrix. In this paper, the method of extracting attribute scattering center is studied. (1) an attribute scattering center extraction method combining alternating projection and orthogonal matching tracking is proposed. Firstly, the SAR synthetic Aperture radar (SAR) image support region of the target is extracted to realize the automatic initialization of the target parameters, which reduces the dictionary dimension and computational complexity, and then estimates the scattering center parameters of the target attributes by orthogonal matching tracking method. Finally, the estimated parameters are modified by alternating projection method. This method can reduce the influence of high coupling between scattering centers of target attributes on the estimation of scattering center parameters and improve the estimation accuracy. In the estimation process of frequency-domain method, the image information of the target is introduced to realize the decoupling between scattering centers, which not only reduces the computational complexity but also improves the precision of parameter estimation.
【學(xué)位授予單位】:西安電子科技大學(xué)
【學(xué)位級(jí)別】:碩士
【學(xué)位授予年份】:2014
【分類號(hào)】:TN957.51
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1 杜蘭;雷達(dá)高分辨距離像目標(biāo)識(shí)別方法研究[D];西安電子科技大學(xué);2007年
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