發(fā)布時(shí)間：2018-06-07 22:47

  本文選題：SAR + 高分辨率��； 參考：《電子科技大學(xué)》2014年碩士論文

【摘要】：相比于單通道合成孔徑雷達(dá)(SAR)系統(tǒng),多通道系統(tǒng)因增加了接收通道而使回波數(shù)據(jù)有了冗余,系統(tǒng)自由度增加,能夠獲取目標(biāo)豐富的細(xì)節(jié)信息,更精準(zhǔn)地從背景雜波和噪聲中區(qū)分出目標(biāo),適用于高分辨率成像和目標(biāo)檢測(cè)技術(shù)研究。多通道系統(tǒng)具有數(shù)據(jù)利用率高、系統(tǒng)成本低、靈活性強(qiáng)等優(yōu)勢(shì),本文以此為背景,將寬帶合成技術(shù)和動(dòng)目標(biāo)檢測(cè)方法同時(shí)應(yīng)用到多通道SAR系統(tǒng)中,研究了基于寬帶合成的距離向高分辨率成像技術(shù)和中心頻率步進(jìn)的多通道SAR動(dòng)目標(biāo)檢測(cè)方法,所做的具體工作及創(chuàng)新如下:1、首先介紹了寬帶合成技術(shù),說明了距離向分辨率的原理和通道數(shù)與距離向分辨率的關(guān)系;然后結(jié)合兩種經(jīng)典的多通道SAR動(dòng)目標(biāo)檢測(cè)技術(shù)分析了多通道SAR系統(tǒng)用于動(dòng)目標(biāo)檢測(cè)中的優(yōu)勢(shì)和存在的問題。2、研究了基于誤差補(bǔ)償?shù)念l域?qū)拵Ш铣煞椒āＪ紫?建立了多通道SAR回波信號(hào)模型。然后,介紹了一種典型的頻域?qū)拵Ш铣煞椒?針對(duì)該方法中同等效相位中心合成帶來的傳輸路徑誤差,結(jié)合仿真實(shí)驗(yàn)分析了其對(duì)寬帶合成的影響,并給出誤差補(bǔ)償方法;針對(duì)該方法中通道不一致帶來的幅相誤差,結(jié)合仿真實(shí)驗(yàn)分析了其對(duì)寬帶合成的影響,并給出誤差補(bǔ)償方法;尤其針對(duì)該方法中的子帶重疊誤差提出一種頻域滾降濾波法,詳細(xì)給出了算法原理及處理步驟,并結(jié)合仿真實(shí)驗(yàn)論證了該誤差補(bǔ)償方法的有效性。最后,針對(duì)這種典型的頻域?qū)拵Ш铣煞椒ù嬖诘倪@三種誤差,采用上述補(bǔ)償方法,獲得了距離向高分辨率的SAR圖像,驗(yàn)證了基于誤差補(bǔ)償?shù)念l域?qū)拵Ш铣煞椒ǖ挠行浴?、提出了圖像域的寬帶合成方法。針對(duì)傳統(tǒng)的寬帶合成技術(shù)存在的運(yùn)算量大、實(shí)時(shí)性差的問題,本文提出基于圖像域的寬帶合成方法:首先,介紹了圖像域?qū)拵Ш铣伤惴ǖ幕舅悸?推導(dǎo)并建立了算法模型;然后,給出了算法步驟和框圖;最后,從理論上說明了在SAR圖像分辨率相當(dāng)?shù)那闆r下,所提的圖像域?qū)拵Ш铣煞椒ㄝ^傳統(tǒng)的寬帶合成方法在運(yùn)算量和實(shí)時(shí)性方面有明顯的優(yōu)勢(shì)。4、研究了中心頻率步進(jìn)的三通道ATI動(dòng)目標(biāo)檢測(cè)及重定位技術(shù)。首先研究了偏置相位中心天線(DPCA)和沿跡干涉(ATI)兩種SAR動(dòng)目標(biāo)檢測(cè)方法,對(duì)比說明了ATI在動(dòng)目標(biāo)檢測(cè)方面有更好的檢測(cè)性能和抗干擾特性;然后,針對(duì)傳統(tǒng)的兩通道ATI無法提取動(dòng)目標(biāo)參數(shù)的問題,重點(diǎn)研究了中心頻率步進(jìn)的三通道ATI動(dòng)目標(biāo)檢測(cè)技術(shù),并通過提取動(dòng)目標(biāo)的相位信息,進(jìn)而估計(jì)目標(biāo)的多普勒參數(shù)和運(yùn)動(dòng)參數(shù),實(shí)現(xiàn)對(duì)動(dòng)目標(biāo)的檢測(cè)和重定位。
[Abstract]:Compared with single channel synthetic Aperture Radar (SAR) system, the multi-channel system increases the echo data redundancy, increases the degree of freedom of the system, and can obtain the rich detailed information of the target. It is more accurate to distinguish targets from background clutter and noise, and is suitable for high resolution imaging and target detection. Multi-channel system has the advantages of high data utilization, low system cost and strong flexibility. In this paper, wideband synthesis technology and moving target detection method are applied to multi-channel SAR system at the same time. The range high resolution imaging technology based on wideband synthesis and the multi-channel SAR moving target detection method based on step by step of center frequency are studied. The specific work and innovation are as follows: 1. Firstly, broadband synthesis technology is introduced. The principle of the range resolution and the relationship between the number of channels and the range resolution are explained. Then, the advantages and problems of moving target detection in multi-channel SAR system are analyzed with two classical multi-channel SAR moving target detection techniques, and the wideband synthesis method in frequency domain based on error compensation is studied. Firstly, the multi-channel SAR echo signal model is established. Then, a typical broadband synthesis method in frequency domain is introduced. Aiming at the transmission path error caused by the same equivalent phase center synthesis in this method, the influence of the method on broadband synthesis is analyzed in combination with the simulation experiment, and the error compensation method is given. Aiming at the amplitude-phase error caused by channel inconsistency in this method, this paper analyzes its influence on wideband synthesis and gives an error compensation method combined with simulation experiments, especially, a frequency-domain rolling filtering method is proposed for the overlapping error of sub-band in this method. The principle and processing steps of the algorithm are given in detail, and the effectiveness of the error compensation method is demonstrated by simulation experiments. Finally, aiming at the three errors of this typical broadband synthesis method in frequency domain, the range high-resolution SAR images are obtained by using the compensation method mentioned above. The effectiveness of the frequency domain wideband synthesis method based on error compensation is verified. 3. A wideband synthesis method in image domain is proposed. Aiming at the problems of large computation and poor real-time performance in traditional wideband synthesis technology, a wideband synthesis method based on image domain is proposed in this paper. Firstly, the basic idea of wideband synthesis algorithm in image domain is introduced, and the algorithm model is derived and established. Then, the algorithm steps and block diagrams are given. Finally, it is theoretically explained that the resolution of SAR images is the same as that of SAR images. Compared with the traditional wideband synthesis method, the proposed wideband synthesis method has obvious advantages in computation and real time performance. A three-channel ATI moving target detection and relocating technique with center frequency step is studied in this paper. In this paper, two kinds of SAR moving target detection methods, DPCA (offset phase center antenna) and ATI (interference along track), are studied. The comparison shows that ATI has better detection performance and anti-jamming performance in moving target detection. In order to solve the problem that traditional two-channel ATI can not extract moving target parameters, a three-channel ATI moving target detection technique with center frequency stepping is studied, and the phase information of moving target is extracted. Then the Doppler parameters and motion parameters of the target are estimated to detect and relocate the moving target.
【學(xué)位授予單位】：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)】：TN957.52

【參考文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 劉齊發(fā);基于現(xiàn)代數(shù)字信號(hào)處理理論提高SAR圖像分辨率[D];武漢理工大學(xué);2008年

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本文編號(hào)：1993127