發(fā)布時間：2018-10-10 16:08

【摘要】：雷達(dá)存在于現(xiàn)代人類生活的各個領(lǐng)域，擁有著不可或缺的重要地位。在實際的使用過程中，線性調(diào)頻連續(xù)波雷達(dá)憑借其發(fā)射功率較低，，距離分辨率較高，不存在探測盲區(qū)，抗干擾能力較強，硬件實現(xiàn)難度較低等優(yōu)點，在各個領(lǐng)域中占據(jù)著越來越重要的位置，因此對線性調(diào)頻連續(xù)波雷達(dá)的研究有著很高的實用價值。 本文通過查閱大量的國內(nèi)外資料和文獻(xiàn)，首先對線性調(diào)頻連續(xù)波雷達(dá)的系統(tǒng)組成和測距原理進(jìn)行了深入研究，詳細(xì)分析了線性調(diào)頻連續(xù)波雷達(dá)系統(tǒng)中的發(fā)射信號、接收信號、差拍信號以及干擾信號，并進(jìn)行實驗仿真；然后重點研究了在理想狀態(tài)下對差拍信號的處理方法，以便能夠得到較為精確的目標(biāo)距離信息，分別對傳統(tǒng)的FFT算法、Chirp-Z算法、譜最大值估計算法、擬合法等幾種算法的原理和實現(xiàn)方法進(jìn)行研究，并使用這幾種算法對差拍信號進(jìn)行處理，通過仿真實驗得出差拍信號主頻以及待測目標(biāo)距離信息；最后提出了一種改進(jìn)的信號處理算法，即將擬合法和Chirp-Z算法相結(jié)合對差拍信號進(jìn)行處理，使用該算法進(jìn)行實驗仿真，得出差拍信號主頻以及待測目標(biāo)的距離。 假設(shè)不同的雷達(dá)參數(shù)設(shè)置以及不同的目標(biāo)距離設(shè)置，分別采取上述幾種算法提取差拍信號的主頻，獲得距離信息，將測距結(jié)果進(jìn)行比較。仿真結(jié)果表明在相同條件下傳統(tǒng)的FFT算法所得目標(biāo)距離誤差較大，Chirp-Z算法、譜最大值估計算法、擬合法這幾種改進(jìn)的算法能夠有效地提高測距的精度，而本文提出的擬合法和Chirp-Z算法相結(jié)合的方法能夠快速準(zhǔn)確的提取差拍信號的中心頻率，能夠較大程度的提高線性調(diào)頻連續(xù)波雷達(dá)的測距精度；而無論采取哪種算法對差拍信號進(jìn)行處理，獲得的目標(biāo)距離精度總是隨著系統(tǒng)調(diào)制帶寬的增大而提高，同時精度還會隨著待測目標(biāo)距離的增大而提高。
[Abstract]:Radar exists in every field of modern human life and has an indispensable position. In the process of practical use, the LFM continuous wave radar has the advantages of low transmitting power, high range resolution, no detection blind area, strong anti-jamming ability, low difficulty in hardware implementation, and so on. The research of linear frequency modulation continuous wave radar has a high practical value because it occupies more and more important position in every field. In this paper, through consulting a lot of domestic and international data and literature, firstly, the system composition and ranging principle of LFM CW radar are deeply studied, and the transmitting signal and receiving signal in LFM CWR system are analyzed in detail. The beat signal and the interference signal are simulated, and the processing method of the beat signal is studied in the ideal condition, so as to obtain the accurate target distance information. The traditional FFT algorithm and the Chirp-Z algorithm are used respectively. The principle and realization of several algorithms, such as spectrum maximum estimation algorithm and fitting method, are studied, and the beat signal is processed by these algorithms. The main frequency of the beat signal and the distance information of the target to be measured are obtained through the simulation experiment. Finally, an improved signal processing algorithm is proposed, which combines the fitting method and the Chirp-Z algorithm to process the beat signal. The algorithm is used for experimental simulation to obtain the main frequency of the beat signal and the distance of the target to be tested. Assuming different radar parameters and different target range settings, the main frequency of the beat signal is extracted by the above algorithms, and the range information is obtained, and the range results are compared. The simulation results show that under the same conditions, the target distance error of the traditional FFT algorithm is large, the Chirp-Z algorithm, the spectrum maximum estimation algorithm and the fitting method can effectively improve the accuracy of ranging. The proposed fitting method combined with Chirp-Z algorithm can extract the center frequency of beat signal quickly and accurately, and can improve the ranging accuracy of LFM CW radar to a large extent. However, no matter which algorithm is adopted to process the beat signal, the precision of the target range is always improved with the increase of the modulation bandwidth of the system, and the accuracy is also improved with the increase of the target distance to be measured.
【學(xué)位授予單位】：河北工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN953.2

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