發(fā)布時間：2018-04-20 04:27

  本文選題：高頻地波雷達(dá) + 艦船目標(biāo)檢測��； 參考：《南京航空航天大學(xué)》2014年碩士論文

【摘要】：作為超視距探測的一種典型,高頻地波雷達(dá)能夠?qū)崿F(xiàn)廣泛區(qū)域內(nèi)的全天候監(jiān)測,因而得到了廣泛的應(yīng)用。低速運(yùn)動的艦船類目標(biāo),在多普勒維受強(qiáng)大的海雜波影響,很難被高頻地波雷達(dá)探測到。如何檢測艦船類低速目標(biāo)一直是高頻地波雷達(dá)的研究難點,本文結(jié)合實際工程項目,從海雜波抑制、恒虛警檢測、檢測前跟蹤等方面開展研究。主要工作如下:提出了基于局部相關(guān)性的改進(jìn)子空間法海雜波抑制方法。在距離-多普勒維依據(jù)鄰近距離單元的局部相關(guān)性,自適應(yīng)劃分海雜波相關(guān)區(qū)域,提高了基于協(xié)方差矩陣的奇異值分解和海雜波子空間劃分準(zhǔn)確性,實現(xiàn)了對海雜波更有效的抑制。實測數(shù)據(jù)表明,一階海雜波功率下降15-20dB,目標(biāo)信號信雜比提高10dB左右。設(shè)計了高頻地波雷達(dá)的CFAR方案�；�于某型高頻地波雷達(dá)實測信號Weibull統(tǒng)計分布及多普勒維易產(chǎn)生虛假目標(biāo)等特性,設(shè)計了PD-MLH-OS組合CFAR檢測方案,包括:先進(jìn)行距離-多普勒-方位三維峰值檢測,再分別進(jìn)行距離維MLH-CFAR檢測,多普勒維OS-CFAR檢測。仿真結(jié)果表明:檢測概率80%時,所提檢測方案優(yōu)于CA-CFAR近5dB。針對目標(biāo)漏檢的情況,提出了基于隔幀外推的改進(jìn)動態(tài)規(guī)劃方法。研究了適合于解決低信噪比下弱小目標(biāo)檢測問題的基于動態(tài)規(guī)劃的檢測前跟蹤算法,并針對原算法因目標(biāo)RCS閃爍、海雜波覆蓋等導(dǎo)致的漏檢情況,提出了基于隔幀外推的改進(jìn)動態(tài)規(guī)劃方法。當(dāng)?shù)趉幀不在第k?1幀的狀態(tài)轉(zhuǎn)移范圍內(nèi)時,考慮k?2幀到第k幀的狀態(tài)轉(zhuǎn)移。仿真分析了算法的檢測有效性,保證了在某一幀漏檢時最終檢測結(jié)果不受影響,且在保證了檢測概率的同時提高了運(yùn)算速度。結(jié)合某實際高頻地波雷達(dá)系統(tǒng),基于脈沖壓縮、數(shù)字波束形成處理流程,設(shè)計了由海雜波抑制、相干積累、恒虛警檢測、動態(tài)規(guī)劃檢測前跟蹤構(gòu)成的高頻地波雷達(dá)艦船目標(biāo)檢測方案。運(yùn)用本方案的實測數(shù)據(jù)處理結(jié)果與船訊網(wǎng)AIS信息對比,驗證了檢測方案的有效性,可對90公里以內(nèi)船長為150m左右的艦船目標(biāo)實現(xiàn)連續(xù)檢測和航跡形成。
[Abstract]:As a typical over-the-horizon detection high frequency ground wave radar can achieve all-weather monitoring in a wide range of areas and has been widely used. Low speed moving ship targets are hard to detect by high frequency ground wave radar because they are influenced by strong sea clutter in Doppler dimension. How to detect low-speed target of ship is always the research difficulty of high-frequency ground wave radar. In this paper, the research is carried out from the aspects of sea clutter suppression, CFAR detection and pre-detection tracking. The main work is as follows: an improved subspace method for suppression of sea clutter based on local correlation is proposed. Based on the local correlation of adjacent distance units, the range-Doppler dimension adaptively divides the correlation region of sea clutter, which improves the accuracy of singular value decomposition based on covariance matrix and subspace partition of sea clutter. More effective suppression of sea clutter is realized. The measured data show that the power of the first order sea clutter decreases by 15-20 dB and the signal-to-clutter ratio of the target signal increases by about 10dB. The CFAR scheme of HF ground wave radar is designed. Based on the characteristics of the Weibull statistical distribution of the measured signals of a high frequency ground wave radar and the easy to produce false targets in the Doppler dimension, a PD-MLH-OS combined CFAR detection scheme is designed, which includes: first, the range Doppler azimuth 3D peak detection is carried out. Then the range dimension MLH-CFAR detection and Doppler dimensional OS-CFAR detection were carried out respectively. The simulation results show that the proposed detection scheme is better than the CA-CFAR nearly 5 dB when the detection probability is 80%. An improved dynamic programming method based on frame extrapolation is proposed for missing detection of target. A dynamic programming based pre-detection tracking algorithm for small and weak target detection under low SNR is studied, and the missed detection caused by RCS flicker and sea clutter coverage of the original algorithm is studied. An improved dynamic programming method based on frame extrapolation is proposed. When the k frame is not within the state transition range of the first frame, the state transition from the second frame to the second frame is considered. The effectiveness of the algorithm is analyzed by simulation, which ensures that the final detection result will not be affected when a frame is missed, and improves the operation speed while ensuring the detection probability. Based on pulse compression and digital beamforming process, a practical high-frequency ground wave radar system is designed to suppress sea clutter, coherent accumulation and CFAR detection. A high frequency ground wave radar ship target detection scheme based on tracking before dynamic programming detection is presented. The validity of the detection scheme is verified by comparing the measured data processing results with the AIS information of the ship information network. The method can realize continuous detection and track formation for ships whose captain is about 150m within 90 km.
【學(xué)位授予單位】：南京航空航天大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：E925;TN958.93
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本文編號：1776254