本文關鍵詞： 逆合成孔徑成像 運動補償 彈道目標 機動目標　出處：《電子科技大學》2014年碩士論文　論文類型：學位論文

【摘要】：逆合成孔徑雷達(Inverse Synthetic Aperture Radar,ISAR)與合成孔徑雷達(Synthetic Aperture Radar,SAR)成像原理相似,均利用大寬帶信號實現距離向高分辨率,利用雷達與目標相對運動中不同散射點產生的不同多普勒差異實現方位向高分辨率,最終得到目標的二維高分辨率成像結果。ISAR主要針對如飛機、彈道導彈、軌道衛(wèi)星等非合作空間目標進行成像,ISAR不同于光學成像,能夠在任何氣候、任何時間進行成像。除此外,ISAR通過處理接收到的目標回波去反演目標特征,從而實現重構目標中心分布,同時又能在窄帶下探測目標位置、軌跡等額外信息,為目標識別提供有力途徑。因此,ISAR成像技術在戰(zhàn)場偵察、防御,衛(wèi)星、天體觀測等有極其重要的應用價值。本文主要對ISAR中以下幾方面進行了詳細研究,包括:ISAR轉臺成像原理,寬帶雷達下目標回波信號分析與處理,ISAR運動補償技術,成像聚焦算法等,其中運動補償中的相位補償部分在本文中重點進行了介紹。除詳細推導了其理論原理與模型外,本文的工作重點是結合仿真與實測數據,驗證論文算法以及提出的改進算法在工程應用中的有效性。文章所涉及的核心內容安排如下:(1)在簡單介紹微波成像原理與目標散射機理的基礎上、概述了ISAR成像基本概念、ISAR成像的應用領域,當前國內外ISAR成像研究現狀及其研究的意義。(2)構建寬帶回波信號模型,進而推導ISAR轉臺成像原理,分析了運動補償對成像的必要性及如何實現方位向聚焦。距離對齊中分析了基于全局能量準則的對齊方法。(3)著重就ISAR運動補償中的相位補償以及時頻成像技術進行了詳細分析,并提出部分改進算法,相位補償部分中基于離散多項式相位變換的自適應聯合時頻補償,時頻成像部分中引入了諧波小波變換。并利用點目標模型進行了仿真驗證。(4)針對飛機目標和彈道中段目標進行了成像算法研究與仿真,將前面章節(jié)提出的算法應用至復雜真實的回波數據,以驗證算法在工程應用上有效性,最后總結飛機與導彈目標成像方法上的區(qū)別。
[Abstract]:Inverse Synthetic Aperture Radarr (ISAR) is similar to synthetic Aperture Radar (SAR) imaging principle. Both use large wideband signals to achieve high range resolution. The high azimuth resolution can be achieved by using different Doppler differences produced by different scattering points in the relative motion of radar and target. Finally, the two-dimensional high-resolution imaging results of target .ISAR are mainly aimed at aircraft and ballistic missile. The imaging of non-cooperative space targets such as orbiting satellites is different from optical imaging and can be performed at any time in any climate. In addition, ISAR inverts the target characteristics by processing the received target echo. In order to reconstruct the center distribution of the target, and at the same time, it can detect the location and trajectory of the target in the narrow band, and provide a powerful way for target recognition. Therefore, ISAR imaging technology can be used in battlefield reconnaissance, defense, satellite, etc. In this paper, the following aspects of ISAR are studied in detail, including the imaging principle of the ISAR turntable, the analysis and processing of target echo signal under wideband radar, and the motion compensation technology of ISAR. The phase compensation of motion compensation is introduced in this paper. Besides the theoretical principle and model derived in detail, the emphasis of this paper is to combine the simulation data with the measured data. To verify the effectiveness of the proposed algorithm and the proposed improved algorithm in engineering applications. The core contents of this paper are arranged as follows: 1) on the basis of a brief introduction of microwave imaging principle and target scattering mechanism, In this paper, the basic concept of ISAR imaging and the application field of ISAR imaging are summarized. At present, the research status and significance of ISAR imaging at home and abroad are summarized. (2) the model of wideband echo signal is constructed, and the imaging principle of ISAR turntable is deduced. The necessity of motion compensation for imaging and how to realize azimuth focusing are analyzed. In range alignment, the alignment method based on global energy criterion is analyzed. An adaptive joint time-frequency compensation based on discrete polynomial phase transformation in phase compensation is proposed. In the part of time-frequency imaging, the harmonic wavelet transform is introduced, and the point target model is used to verify the simulation. The algorithm proposed in the previous chapter is applied to complex real echo data to verify the effectiveness of the algorithm in engineering applications. Finally, the differences between the imaging methods of aircraft and missile targets are summarized.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TN957.52

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相關期刊論文 前1條

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本文編號：1493268