機(jī)載SAR回波仿真與圖像模擬
發(fā)布時(shí)間：2019-06-27 17:13
【摘要】：合成孔徑雷達(dá)(SAR)具有高分辨等諸多優(yōu)點(diǎn),機(jī)載SAR回波仿真和圖像模擬對(duì)于整個(gè)機(jī)載SAR系統(tǒng)的開發(fā)具有重要作用。機(jī)載SAR回波仿真和圖像模擬是希望能夠通過模擬的技術(shù)獲得逼近真實(shí)的回波數(shù)據(jù)和圖像,本文基于此點(diǎn)展開研究工作,全文的主要工作內(nèi)容如下:(1)對(duì)SAR的合成孔徑原理和它如何獲得高分辨率的工作過程,和回波信號(hào)的特點(diǎn)進(jìn)行了分析,以及如何通過回波信號(hào)得到SAR圖像的成像過程進(jìn)行了研究。(2)對(duì)SAR回波仿真方法進(jìn)行了研究,以機(jī)載SAR回波仿真基本理論為出發(fā)點(diǎn),在傳統(tǒng)的時(shí)域仿真方法的基礎(chǔ)上研究了一種快速時(shí)域仿真方法。針對(duì)時(shí)域仿真方法計(jì)算量大的缺點(diǎn),頻域回波仿真方法更能滿足實(shí)時(shí)性的需求,研究了基于IωK回波仿真方法,對(duì)比傳統(tǒng)頻域仿真,能夠模擬SAR的距離徙動(dòng),因此能夠有更加精確的回波,最后,給出了點(diǎn)目標(biāo)和面目標(biāo)的時(shí)域仿真和基于IωK回波仿真的實(shí)驗(yàn)結(jié)果。(3)對(duì)航跡偏移下的SAR回波仿真和成像進(jìn)行了研究,根據(jù)SAR的運(yùn)動(dòng)誤差模型,分析了航跡偏移下的回波信號(hào)以及相位誤差,導(dǎo)致了方位向的調(diào)頻率估計(jì)誤差,因此對(duì)有運(yùn)動(dòng)誤差情況下運(yùn)用MD算法方位向調(diào)頻率估計(jì)展開了研究,最后給出了航跡偏移下的回波仿真以及用MD算法方位向調(diào)頻率估計(jì)后的仿真成像結(jié)果。(4)根據(jù)參與項(xiàng)目的要求,對(duì)超寬帶SAR信號(hào)展開了研究,超寬帶信號(hào)能夠使SAR獲得更高的分辨率。首先對(duì)合成帶寬技術(shù)進(jìn)行了研究,通過發(fā)射步進(jìn)頻率信號(hào)采用合成帶寬技術(shù)獲得寬帶信號(hào),提高分辨率。另外為了降低采樣率采用去斜率的方法降低帶寬后進(jìn)行處理,并對(duì)去斜率后的SAR分辨率和成像算法進(jìn)行了研究,最后給出了合成帶寬的仿真結(jié)果和去斜率后的信號(hào)及去斜率后的SAR成像仿真結(jié)果。綜上所述,本文主要圍繞以SAR回波仿真得到SAR模擬圖像,研究了主要的回波仿真方法,以及航跡偏移情況下和超寬帶信號(hào)下的回波仿真和成像研究。
[Abstract]:Synthetic Aperture Radar (SAR) has many advantages, such as high resolution and so on. Airborne SAR echo simulation and image simulation play an important role in the development of the whole airborne SAR system. Airborne SAR echo simulation and image simulation hope that the echo data and images can be approximated by simulation technology. based on this point, the main contents of this paper are as follows: (1) the synthetic aperture principle of SAR and how to obtain high resolution are analyzed, and the characteristics of echo signal are analyzed. And how to get SAR image imaging process from echo signal is studied. (2) the SAR echo simulation method is studied. Based on the basic theory of airborne SAR echo simulation, a fast time-domain simulation method is studied on the basis of the traditional time-domain simulation method. In order to solve the problem that the time domain simulation method has a large amount of computation, the frequency domain echo simulation method can better meet the real-time requirements. Compared with the traditional frequency domain simulation method, the frequency domain echo simulation method is studied. Compared with the traditional frequency domain simulation, it can simulate the range migration of SAR, so it can have a more accurate echo. The time domain simulation of point target and surface target and the experimental results based on I 蠅 K echo simulation are given. (3) the SAR echo simulation and imaging under track migration are studied. According to the motion error model of SAR, the echo signal and phase error under track migration are analyzed, which leads to the azimuth frequency modulation estimation error. Therefore, the azimuth modulation frequency estimation using MD algorithm is studied in the case of motion error. Finally, the echo simulation under track migration and the simulation imaging results after azimuth modulation frequency estimation with MD algorithm are given. (4) according to the requirements of the participating project, the ultra-broadband SAR signal is studied, and the ultra-broadband signal can make SAR obtain higher resolution. Firstly, the synthetic bandwidth technology is studied, and the broadband signal is obtained by transmitting the step frequency signal by using the synthetic bandwidth technology to improve the resolution. In addition, in order to reduce the sampling rate, the method of de-slope is used to reduce the bandwidth, and the SAR resolution and imaging algorithm after de-slope are studied. finally, the simulation results of synthetic bandwidth, the signal after de-slope and the simulation results of SAR imaging after de-slope are given. To sum up, this paper mainly focuses on the SAR simulation image obtained by SAR echo simulation, and studies the main echo simulation methods, as well as the echo simulation and imaging research under the condition of track offset and ultra-broadband signal.
【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
本文編號(hào)：2506986
[Abstract]:Synthetic Aperture Radar (SAR) has many advantages, such as high resolution and so on. Airborne SAR echo simulation and image simulation play an important role in the development of the whole airborne SAR system. Airborne SAR echo simulation and image simulation hope that the echo data and images can be approximated by simulation technology. based on this point, the main contents of this paper are as follows: (1) the synthetic aperture principle of SAR and how to obtain high resolution are analyzed, and the characteristics of echo signal are analyzed. And how to get SAR image imaging process from echo signal is studied. (2) the SAR echo simulation method is studied. Based on the basic theory of airborne SAR echo simulation, a fast time-domain simulation method is studied on the basis of the traditional time-domain simulation method. In order to solve the problem that the time domain simulation method has a large amount of computation, the frequency domain echo simulation method can better meet the real-time requirements. Compared with the traditional frequency domain simulation method, the frequency domain echo simulation method is studied. Compared with the traditional frequency domain simulation, it can simulate the range migration of SAR, so it can have a more accurate echo. The time domain simulation of point target and surface target and the experimental results based on I 蠅 K echo simulation are given. (3) the SAR echo simulation and imaging under track migration are studied. According to the motion error model of SAR, the echo signal and phase error under track migration are analyzed, which leads to the azimuth frequency modulation estimation error. Therefore, the azimuth modulation frequency estimation using MD algorithm is studied in the case of motion error. Finally, the echo simulation under track migration and the simulation imaging results after azimuth modulation frequency estimation with MD algorithm are given. (4) according to the requirements of the participating project, the ultra-broadband SAR signal is studied, and the ultra-broadband signal can make SAR obtain higher resolution. Firstly, the synthetic bandwidth technology is studied, and the broadband signal is obtained by transmitting the step frequency signal by using the synthetic bandwidth technology to improve the resolution. In addition, in order to reduce the sampling rate, the method of de-slope is used to reduce the bandwidth, and the SAR resolution and imaging algorithm after de-slope are studied. finally, the simulation results of synthetic bandwidth, the signal after de-slope and the simulation results of SAR imaging after de-slope are given. To sum up, this paper mainly focuses on the SAR simulation image obtained by SAR echo simulation, and studies the main echo simulation methods, as well as the echo simulation and imaging research under the condition of track offset and ultra-broadband signal.
【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
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