本文關(guān)鍵詞：超寬帶穿墻雷達(dá)模擬及目標(biāo)探測(cè)方法研究　出處：《南京大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 穿墻雷達(dá) FDTD 反向投影算法 墻體參數(shù)估計(jì)

【摘要】：城市作戰(zhàn)、反恐維穩(wěn)和災(zāi)后救援等諸多方面都有著穿透障礙物探測(cè)目標(biāo)的需求。相比其他的穿透探測(cè)技術(shù),超寬帶穿墻雷達(dá)系統(tǒng)具有顯著的優(yōu)勢(shì),其工作不受視覺(jué)條件、環(huán)境變化和天氣變化等因素的影響。本文利用電磁仿真算法對(duì)超寬帶穿墻雷達(dá)系統(tǒng)進(jìn)行了模擬,然后進(jìn)行了墻后目標(biāo)探測(cè)研究。超寬帶穿墻雷達(dá)系統(tǒng)的機(jī)制主要有沖擊脈沖系統(tǒng)、步進(jìn)頻系統(tǒng)、線性調(diào)頻系統(tǒng)之分,本文研究基于沖擊脈沖機(jī)制的超寬帶穿墻雷達(dá)系統(tǒng)。首先介紹了關(guān)于穿墻雷達(dá)成像的工作原理,建立了墻體數(shù)學(xué)模型,推導(dǎo)了墻體對(duì)于雷達(dá)信號(hào)的影響。采用窄脈沖超寬帶發(fā)射信號(hào),給出了雷達(dá)回波信號(hào)的表達(dá)式和回波信號(hào)中干擾信號(hào)的去除方法。采用時(shí)域有限差分法(FDTD)進(jìn)行電磁仿真。FDTD是一種麥克斯韋方程組的近似解法。文中介紹了 FDTD算法的三個(gè)要點(diǎn):麥克斯韋方程組的差分形式轉(zhuǎn)化,解的穩(wěn)定性條件,吸收邊界條件。以FDTD算法為基礎(chǔ)建立了超寬帶穿墻雷達(dá)系統(tǒng)的電磁仿真模型,給出了仿真模型的相關(guān)參數(shù)設(shè)置方法和信號(hào)處理使用的相關(guān)軟件說(shuō)明。研究了三角定位和后向投影算法這兩種穿墻雷達(dá)成像算法。分別研究和比較了雷達(dá)發(fā)射信號(hào)在自由空間、和墻體中的傳輸過(guò)程。根據(jù)墻體對(duì)算法的影響,在存在墻體的環(huán)境下對(duì)算法進(jìn)行了修正。研究了單點(diǎn)和多點(diǎn)靜止目標(biāo)的探測(cè),進(jìn)行了 MATLAB仿真,給出了成像結(jié)果。研究了動(dòng)目標(biāo)的探測(cè),進(jìn)行了仿真,繪制了目標(biāo)的運(yùn)動(dòng)軌跡。進(jìn)行了超寬帶穿墻雷達(dá)的生命探測(cè)的簡(jiǎn)單仿真,給出了仿真結(jié)果。上述兩種成像算法都需要事先已知墻體參數(shù)(墻體厚度和墻體的相對(duì)介電常數(shù)),實(shí)際應(yīng)用時(shí)墻體參數(shù)往往未知。對(duì)于墻體參數(shù)未知的情況,提出兩種解決方法:一是分析墻體參數(shù)對(duì)目標(biāo)位置的影響,根據(jù)不同參數(shù)下目標(biāo)的位置的改變生成目標(biāo)位置變化曲線,求不同配置天線下的曲線的交點(diǎn);二是根據(jù)墻體兩面反射信號(hào)幅度的變化估計(jì)墻體的參數(shù)。給出了上述兩種方法的估計(jì)算法,進(jìn)行了仿真研究。結(jié)果表明,上述兩種方法均有效。最后,總結(jié)了全文的研究工作,并對(duì)下一步的改進(jìn)和深入研究方向進(jìn)行了展望。
[Abstract]:Urban operations, anti-terrorist stability, post-disaster rescue and many other aspects have the need to detect targets through obstacles. Compared with other penetration detection technology, UWB wall penetrating radar system has a significant advantage. Its work is not affected by the visual condition, environment change and weather change, etc. In this paper, the ultra-wideband wall-penetrating radar system is simulated by electromagnetic simulation algorithm. The main mechanisms of UWB wall-penetrating radar system are impulse system, step frequency system and linear frequency modulation system. In this paper, the ultra-wideband (UWB) penetrating wall radar system based on impulse mechanism is studied. Firstly, the working principle of penetrating wall radar imaging is introduced, and the wall mathematical model is established. The influence of wall on radar signal is deduced. The narrow-pulse ultra-wideband (UWB) transmission signal is adopted. The expression of radar echo signal and the method of removing interference signal from echo signal are given. Electromagnetic simulation. FDTD is an approximate solution to Maxwell equations. Three key points of FDTD algorithm are introduced: the difference transformation of Maxwell equations. Based on the FDTD algorithm, the electromagnetic simulation model of ultra-wideband wall-penetrating radar system is established. The related parameter setting method of simulation model and the software explanation of signal processing are given. Two imaging algorithms, triangulation and backward projection, are studied, and radar transmitting signals are studied and compared respectively. Sign is in free space. According to the influence of the wall on the algorithm, the algorithm is modified in the environment where the wall exists. The detection of single and multi-point static targets is studied, and the MATLAB simulation is carried out. The imaging results are given, the detection of moving target is studied, the simulation is carried out, the moving track of the target is drawn, and the simple simulation of life detection of UWB wall-penetrating radar is carried out. The simulation results are given. The above two imaging algorithms need to know the wall parameters (the wall thickness and the relative dielectric constant of the wall) in advance. In practical application, the wall parameters are often unknown. For the case where the wall parameters are unknown. Two solutions are proposed: one is to analyze the influence of wall parameters on the position of the target, according to the change of the position of the target under different parameters to generate the curve of the change of the position of the target, and to find the intersection of the curve under the different configuration of antenna; The second is to estimate the parameters of the wall according to the variation of the amplitude of the reflected signal on both sides of the wall. The estimation algorithm of the two methods mentioned above is given and the simulation research is carried out. The results show that the two methods are effective. Finally. The research work of this paper is summarized, and the future improvement and further research direction are prospected.
【學(xué)位授予單位】：南京大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TN958

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