【摘要】：多輸入多輸出(Multi-Input Multi-Output,MIMO)雷達(dá)作為一種新體制雷達(dá)技術(shù),已受到國內(nèi)外科研工作者的廣泛關(guān)注。由于其綜合利用陣列與分集技術(shù),引入了遠(yuǎn)多于傳統(tǒng)合成孔徑雷達(dá)(Synthetic Aperture Radar,SAR)的等效觀測通道和處理信號(hào)的自由度,可以有效解決傳統(tǒng)SAR中高分辨率和寬測繪帶之間的矛盾。然而,由于MIMO雷達(dá)多收發(fā)陣列的結(jié)構(gòu)特點(diǎn),傳統(tǒng)的雷達(dá)成像算法不能被直接利用,同時(shí)發(fā)射波形彼此之間的相互干擾、MIMO雷達(dá)平臺(tái)的等效相位中心誤差、雷達(dá)的布陣方式都會(huì)對MIMO-SAR成像帶來巨大的影響。針對這些問題,本文從MIMO-SAR的工作原理出發(fā),分別對MIMO雷達(dá)的波形優(yōu)化、波形加窗處理、MIMO的等效相位中心誤差和多輸入多輸出的雷達(dá)陣列布陣方法等展開了深入的研究。同時(shí)根據(jù)發(fā)射波形的特點(diǎn),對成像算法進(jìn)行改進(jìn),并最終實(shí)現(xiàn)MIMO-SAR的高分辨率和寬測繪帶成像。論文的主要工作包括:1.從MIMO雷達(dá)發(fā)射波形的正交性、多普勒敏感性等方面綜合考慮,引入了一種雙調(diào)頻斜率波形的信號(hào)模型,并重點(diǎn)分析了該信號(hào)的互相關(guān)性、自相關(guān)性,以及多普勒特性。為提高該信號(hào)的脈沖壓縮性能,對波形進(jìn)行加窗優(yōu)化設(shè)計(jì)。2.通過分析等效相位中心誤差對MIMO雷達(dá)成像的影響,構(gòu)建了等效相位中心的誤差模型,并給出了相應(yīng)的補(bǔ)償方法。同時(shí)根據(jù)MIMO雷達(dá)多發(fā)多收陣列形式,對MIMO-SAR的收發(fā)陣列進(jìn)行了優(yōu)化配置。3.針對雙調(diào)頻斜率波形(Double Frequency Slope,DFS)波形的模型,對MIMO-SAR回波進(jìn)行建模。重點(diǎn)分析了回波在距離多普勒域的特點(diǎn),并推導(dǎo)了距離向的脈沖壓縮函數(shù)和相位補(bǔ)償函數(shù),提出了一種基于雙調(diào)頻斜率波形在MIMO-SAR中的成像方案,并通過與正交頻分復(fù)用線性調(diào)頻信號(hào)的成像性能對比,突出了DFS波形在MIMO-SAR中的優(yōu)勢。4.針對遠(yuǎn)距離,寬場景和高分辨率下存在的距離徙動(dòng)問題,提出了一種基于DFS波形的頻率域校正距離彎曲的成像方法,并通過真實(shí)寬場景下的成像,驗(yàn)證了MIMO-SAR在解決高分辨率和寬測繪帶之間矛盾的有效性。
[Abstract]:As a new system radar technology, multiple input multiple output (Multi-Input Multi-Output,MIMO) radar has been paid more and more attention by researchers at home and abroad. Because of its comprehensive use of array and diversity technology, the equivalent observation channel and the degree of freedom of signal processing, which are far more than traditional synthetic aperture radar (Synthetic Aperture Radar,SAR), can effectively solve the contradiction between high resolution and wide mapping band in traditional SAR. However, due to the structural characteristics of multi-transceiver array of MIMO radar, the traditional radar imaging algorithm can not be directly used, and at the same time, the mutual interference between the transmitted waveforms and the equivalent phase center error of the MIMO radar platform. Radar array will have a great impact on MIMO-SAR imaging. Based on the principle of MIMO-SAR, the waveform optimization, waveform windowing, equivalent phase center error of MIMO and multi-input and multi-output array of MIMO radar are studied in this paper. At the same time, according to the characteristics of the transmitting waveform, the imaging algorithm is improved, and finally the high resolution and wide mapping band imaging of MIMO-SAR is realized. The main work of the thesis includes: 1. Considering the orthogonality and Doppler sensitivity of MIMO radar transmitting waveform, a signal model of double frequency modulation slope waveform is introduced, and the cross-correlation, autocorrelation and Doppler characteristics of the signal are analyzed. In order to improve the pulse compression performance of the signal, the waveform is optimized with window. 2. By analyzing the effect of the equivalent phase center error on the MIMO radar imaging, the error model of the equivalent phase center is constructed, and the corresponding compensation method is given. At the same time, according to the MIMO radar multi-receiving array form, the MIMO-SAR transceiver array is optimized. 3. 3. Based on the model of double frequency modulation slope waveform (Double Frequency Slope,DFS), the MIMO-SAR echo is modeled. The characteristics of echo in range Doppler domain are analyzed emphatically, and the pulse compression function and phase compensation function in range direction are derived. An imaging scheme based on double frequency modulation slope waveform in MIMO-SAR is proposed. Compared with the imaging performance of orthogonal frequency division multiplexing (OFDM) LFM signal, the advantages of DFS waveform in MIMO-SAR are highlighted. 4. Aiming at the range migration problem in long range, wide scene and high resolution, a range bending correction method in frequency domain based on DFS waveform is proposed. The validity of MIMO-SAR in solving the contradiction between high resolution and wide mapping band is verified.
【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)期刊論文 前1條

1 張娟;張林讓;劉楠;;MIMO雷達(dá)最大似然波達(dá)方向估計(jì)方法[J];系統(tǒng)工程與電子技術(shù);2009年06期

，

本文編號(hào)：2292386