發(fā)布時(shí)間：2018-06-26 18:29

  本文選題：低頻段 + 外輻射源雷達(dá)　； 參考：《武漢大學(xué)》2016年博士論文

【摘要】：外輻射源雷達(dá)因具有綠色環(huán)保、抗隱身特性、抗輻射摧毀、低成本易部署等諸多優(yōu)點(diǎn)引起了國(guó)內(nèi)外學(xué)者的關(guān)注而成為近十年來(lái)的研究熱點(diǎn)。隨著國(guó)內(nèi)外研究機(jī)構(gòu)對(duì)外輻射源雷達(dá)深入而廣泛的研究,當(dāng)前在理論研究和技術(shù)實(shí)現(xiàn)上已出現(xiàn)不少突破性進(jìn)展。與此同時(shí),新的應(yīng)用場(chǎng)景的不斷出現(xiàn)也帶來(lái)了許多新的研究課題,亟待解決。圍繞著特定應(yīng)用場(chǎng)景中如何實(shí)現(xiàn)陣列排布的最優(yōu)化、如何對(duì)直達(dá)波干擾進(jìn)行有效抑制、如何實(shí)現(xiàn)信號(hào)的實(shí)時(shí)處理,本文就陣列信號(hào)處理若干關(guān)鍵技術(shù)進(jìn)行了討論與研究,具體工作如下：(1)針對(duì)常規(guī)陣型在外輻射源雷達(dá)特定應(yīng)用場(chǎng)景中適應(yīng)性差的問(wèn)題,提出了適用于最遠(yuǎn)探測(cè)距離的方向性系數(shù)最優(yōu)準(zhǔn)則,以及適用于全方位最小定向誤差的峰值旁瓣比(PSLR)準(zhǔn)則,論證了陣列方向性系數(shù)與陣元坐標(biāo)的關(guān)系、一維陣列間距微小擾動(dòng)與旁瓣電平的關(guān)系,解決了兩類(lèi)典型場(chǎng)景中限定陣元數(shù)量情況下的外輻射源雷達(dá)陣列排布最優(yōu)化問(wèn)題。(2)基于DRM數(shù)字調(diào)幅廣播的特點(diǎn),提出了一種利用直達(dá)波頻率導(dǎo)頻信號(hào)的高頻外輻射源雷達(dá)接收陣列幅相一致性校正新方法。首先介紹了DRM廣播的信號(hào)結(jié)構(gòu),分析了其導(dǎo)頻信號(hào)作為校正源的可行性,考慮到高頻段電磁環(huán)境和傳播環(huán)境的時(shí)變非平穩(wěn)特性,接著提出了一種基于平移不變陣元偶在時(shí)間上優(yōu)選直達(dá)波校正數(shù)據(jù)的方法,最后結(jié)合地波模式和天波傳播模式高頻外輻射源雷達(dá)實(shí)測(cè)多通道數(shù)據(jù),比較了該方法與其他輔助定標(biāo)源方法用于接收陣列校正的效果,分析結(jié)果證實(shí)了該方法的有效性。(3)針對(duì)常規(guī)自適應(yīng)波束形成技術(shù)在外輻射源雷達(dá)強(qiáng)直達(dá)波干擾下效果差的問(wèn)題,提出了基于線(xiàn)性約束最小方差(LCMV)的直達(dá)波零陷靜態(tài)波束形成方案,以及利用協(xié)方差矩陣錐化(CMT)技術(shù)進(jìn)行直達(dá)波零陷展寬的穩(wěn)健自適應(yīng)波束形成方案,在仿真分析基礎(chǔ)上對(duì)該方案進(jìn)行了實(shí)測(cè)數(shù)據(jù)處理驗(yàn)證,實(shí)現(xiàn)了外輻射源雷達(dá)對(duì)直達(dá)波干擾的有效抑制、降低了雜波譜功率、提高了系統(tǒng)目標(biāo)檢測(cè)性能。(4)針對(duì)單調(diào)頻廣播外輻射源雷達(dá)面臨的帶寬時(shí)變及RCS閃爍等問(wèn)題,提出了多調(diào)頻信號(hào)聯(lián)合探測(cè)的實(shí)驗(yàn)方案,并利用武漢大學(xué)研制的多調(diào)頻外輻射源雷達(dá)系統(tǒng)開(kāi)展了外場(chǎng)實(shí)驗(yàn)驗(yàn)證。首先闡述了多調(diào)頻廣播外輻射源雷達(dá)的工作原理,在信號(hào)特性統(tǒng)計(jì)分析的基礎(chǔ)上論證了多調(diào)頻信號(hào)聯(lián)合探測(cè)的必要性和優(yōu)越性,推導(dǎo)了調(diào)頻信號(hào)數(shù)量與目標(biāo)檢測(cè)概率的關(guān)系,最后展示了實(shí)測(cè)數(shù)據(jù)處理結(jié)果并對(duì)結(jié)果進(jìn)行統(tǒng)計(jì)分析。(5)針對(duì)外輻射源雷達(dá)在使用較大帶寬信號(hào)引起的處理難度增加問(wèn)題,提出了基于GPU并行計(jì)算以實(shí)現(xiàn)DTMB信號(hào)實(shí)時(shí)處理的解決方案,分析了CUDA架構(gòu)下的信號(hào)重構(gòu)、雜波抑制、匹配濾波等算法的并行化處理流程,開(kāi)發(fā)了模塊化的程序軟件,通過(guò)對(duì)不同時(shí)段多場(chǎng)連續(xù)數(shù)據(jù)的測(cè)試,實(shí)現(xiàn)8 MHz帶寬信號(hào)了實(shí)時(shí)處理。
[Abstract]:External emitter radar has attracted the attention of scholars at home and abroad because of its advantages of green environment protection, anti-stealth, anti-radiation destruction, low cost and easy deployment, and has become a research hotspot in recent ten years. With the deep and extensive research of external emitter radar at home and abroad, there have been many breakthroughs in theoretical research and technical realization. At the same time, the emergence of new application scenes has brought many new research topics to be solved. Focusing on how to optimize array arrangement, how to suppress direct wave interference effectively, and how to realize real-time signal processing in a specific application scenario, this paper discusses and studies some key technologies of array signal processing. The main works are as follows: (1) aiming at the problem of poor adaptability in the specific application scene of conventional array external emitter radar, an optimal criterion of directivity coefficient suitable for the farthest detection range is proposed. And the peak sidelobe ratio (PSLR) criterion, which is suitable for the omnidirectional minimum orientation error, is discussed. The relationship between array directivity coefficient and array element coordinates, the relation between one-dimensional array spacing tiny disturbance and sidelobe level is proved. In this paper, we solve the problem of optimizing the array arrangement of external emitter radar in the case of limiting the number of array elements in two typical scenarios. (2) based on the characteristics of DRM digital AM broadcasting, A new method for correcting amplitude and phase coherence of high frequency external emitter radar receiving array using direct wave frequency pilot signal is proposed. Firstly, the signal structure of DRM broadcasting is introduced, and the feasibility of using the pilot signal as the correction source is analyzed. The time-varying non-stationary characteristics of the electromagnetic and propagation environments in the high frequency range are considered. Then a method based on the translational invariant array element pair to select the direct wave correction data in time is proposed. Finally, combined with the ground wave mode and the sky-wave propagation mode, the multi-channel data of the high-frequency external emitter radar are measured. The effectiveness of this method in receiving array correction is compared with that of other auxiliary calibration methods. The results show that the method is effective. (3) the conventional adaptive beamforming technique has poor effect under strong direct wave interference of external emitter radar. A direct zero trapping static beamforming scheme based on linear constrained minimum variance (LCMV) is proposed, and a robust adaptive beamforming scheme based on covariance matrix conization (CMT) is proposed. On the basis of simulation and analysis, the method is verified by practical data processing, which realizes the effective suppression of direct wave interference by external emitter radar, and reduces the power of clutter spectrum. The performance of system target detection is improved. (4) aiming at the problems of time-varying bandwidth and RCS scintillation in the external emitter radar with single FM broadcast, the experimental scheme of joint detection of multi-frequency modulation signals is proposed. The field experiments are carried out using the multi-FM external emitter radar system developed by Wuhan University. At first, the working principle of external emitter radar with multi-frequency modulation broadcasting is expounded, and the necessity and superiority of joint detection of multi-frequency modulation signals are demonstrated on the basis of statistical analysis of signal characteristics, and the relationship between the number of FM signals and the probability of target detection is deduced. Finally, the processing results of the measured data are shown and the results are statistically analyzed. (5) aiming at the problem of increasing the processing difficulty caused by the use of large bandwidth signals in the external emitter radar, This paper presents a solution to realize DTMB signal real-time processing based on GPU parallel computing, analyzes the parallel processing flow of signal reconstruction, clutter suppression, matched filtering and other algorithms under CUDA architecture, and develops a modularized program software. The 8 MHz bandwidth signal is processed in real time by testing the continuous data of different time periods.
【學(xué)位授予單位】：武漢大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類(lèi)號(hào)】：TN957.51
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本文編號(hào)：2071006