本文關鍵詞：分布式全相參雷達參數估計及ISAR成像方法研究　出處：《北京理工大學》2015年博士論文　論文類型：學位論文

  更多相關文章： 分布式相參雷達 頻率步進信號 逆合成孔徑雷達 運動補償 相參參數估計 高分辨像重建

【摘要】：隨著航空航天技術的快速發(fā)展，全球空間競爭日趨激烈，軍事力量呈現空天一體化趨勢�？仗炷繕说奶綔y、識別以及監(jiān)視在未來空間攻防對抗中起著至關重要的作用。分布式全相參雷達具有探測威力強、時空分辨率高的優(yōu)勢，滿足當前遠程雷達的戰(zhàn)術機動性需求，且制造工藝相對簡單、成本低，是當前空間監(jiān)視雷達的重要發(fā)展方向。雖然分布式相參雷達已實現原理驗證，但當前仍處于初期發(fā)展階段，尚存在不少關鍵技術問題有待研究與改善。 本論文研究的分布式全相參雷達采用頻率步進波形作為基本發(fā)射波形，發(fā)射單元集中式部署以實現發(fā)射相參，接收單元分布式部署以實現高分辨的分布式逆合成孔徑雷達(ISAR)成像。針對該分布式全相參雷達體制，主要對其中的關鍵問題分布式全相參與分布式ISAR高分辨成像進行了深入的研究與探討，主要的研究內容概述如下： 1.研究了基于頻率步進寬帶波形的分布式全相參雷達信號建模及相參性能分析。建立了基于頻率步進波形的全相參雷達信號模型，包括接收相參參數估計模型與發(fā)射相參誤差信號模型；基于接收相參參數估計模型，詳盡地推導了相參參數的克拉美羅界（CRLB），分析發(fā)現頻率步進波形具有實現高精度相參參數估計的潛力；基于發(fā)射相參誤差模型，詳盡地分析了頻率步進波形下實現發(fā)射相參的參數估計精度需求；此外，還對發(fā)射相參對發(fā)射單元的幾何配置約束進行了分析；最終，結合估計精度需求與CRLB，對基于頻率步進寬帶波形的分布式雷達實現全相參的信噪比要求進行了仿真分析，這對分布式相參雷達的設計與實現具有了重要的指導意義。 2.研究了基于頻率步進波形的分布式雷達相參參數估計方法。建立了頻率步進波形的高分辨距離像重建模型，分別提出了基于相關系數后向投影與最小二乘估計的高分辨距離像重建方法，分析了兩種重建方法對頻率步進間隔的無模糊約束條件，并通過仿真驗證了提出的兩種距離像重建法的有效性與可行性；此外，針對分布式雷達的相參參數估計問題，分別提出了基于包絡熵快速相關的相參延時差估計方法以及基于包絡相關粗估計與精搜索相結合的相參相位估計方法。最終通過仿真驗證了提出方法在精度與效率方面的估計性能，，為實現發(fā)射相參以及分布式ISAR高分辨成像提供了支撐。 3.研究了基于圖像熵的分布式相參ISAR高分辨成像方法。建立了廣義的分布式ISAR成像信號模型，理論推導了雙基地ISAR成像平面與回波數據關系；針對平動補償中的距離包絡對齊與平動相位校正問題，提出了熵準則下基于二次逼近迭代原理的參數尋優(yōu)方法，實現了魯棒的包絡對齊以及精確的平動相位校正。其中，距離對齊方法還采用了循環(huán)級聯濾波處理的方法，克服了局部極值造成的全局最優(yōu)收斂問題，并采用仿真與實測數據驗證了提出迭代估計方法的魯棒性與精確性；針對雙基地ISAR圖像重建，提出了基于ISAR后向投影的轉動中心與角速度估計方法，獲得各子天線單元成像的投影幾何關系，解決了回波數據的空間對齊問題，從而實現了各接收單元在同一空間坐標系下的ISAR圖像重建；最終，基于各重建ISAR圖像，進行了接收相參處理，實現了分布式全相參ISAR的高分辨圖像融合，并通過仿真驗證了提出方法的有效性，證明了提出方法可以為目標識別提供高分辨信息。
[Abstract]:With the rapid development of aerospace technology, global competition is becoming increasingly fierce, military power has the tendency of air and space integration. Space target recognition and detection, monitoring plays an important role in future space attack defense confrontation. Distributed coherent radar detection has strong power, high spatial and temporal resolution advantage, meet the remote radar tactical mobility the demand, and the manufacturing process is relatively simple, low cost, is an important development direction of current space surveillance radar. Although distributed coherent radar has been implemented to verify the principle, but the current is still in the early stage of development, there are still many problems to be studied and improved. The key technology
This paper studies the distributed coherent radar using stepped frequency waveform as the basic waveform, transmission unit of centralized deployment in order to achieve coherent emission and receiving unit to realize the distributed deployment of distributed high resolution inverse synthetic aperture radar (ISAR) imaging. According to the distribution of full coherent radar is one of the key issues of distributed phase in distributed ISAR conducted in-depth research and discussion of high resolution imaging, the main research contents outline as follows:
1. the analysis of distributed step frequency wideband waveform coherent radar signal modeling and performance. Based on a coherent coherent radar signal model of step frequency waveform based on coherent emission model and includes the error signal model to estimate the parameter estimation model based on coherent receiver; receiving phase parameters, detailed derivation of coherent parameters Clarke Meiluo circle (CRLB), analysis found that the stepped frequency is to achieve high accuracy of parameter estimation of coherent potential waveform; coherent emission error model based on the detailed analysis of the stepped frequency waveform to achieve emission parameters parameter estimation accuracy requirements; in addition, the emission of coherent emission unit geometric configuration constraints are analyzed; finally, combined with the estimation accuracy requirement and CRLB of distributed radar based on stepped frequency waveform to achieve broadband coherent SNR requirements are simulated and divided It is of great significance to the design and implementation of distributed coherent radar.
2. study on the estimation method of distributed radar parameters of step frequency waveform based on stepped frequency waveform is established. The high resolution range profile reconstruction model, are proposed to estimate the projection and least squares based on correlation coefficient after high resolution range image reconstruction method, fuzzy constraints analysis of two kinds of reconstruction methods in the frequency interval the two step, and proposed the effectiveness and feasibility of image reconstruction method is verified by simulation; in addition, for the problem of estimating the parameters of the distributed coherent radar, respectively, a method is proposed to estimate the coherent phase envelope entropy fast correlation parameter estimation method based on delay and envelope correlation coarse estimation and fine search based on the combination of. Finally through the simulation shows that the proposed method estimates the performance in terms of accuracy and efficiency, to achieve the emission of coherent and distributed ISAR imaging provides high resolution Support.
3. the study of the high resolution imaging method based on ISAR distributed coherent image entropy is established. The distributed ISAR imaging signal model is generalized, theoretical derivation of the bistatic ISAR imaging plane and echo data; for motion compensation in the distance alignment and translational phase correction, two parameter iteration optimization method based on principle put forward the entropy, to achieve robust and precise alignment of the translational phase correction. The range alignment method also adopts the method of cyclic cascade filtering, to overcome the global convergence problem caused by the local extremum, and the proposed iterative estimation of robustness and accuracy of the method used for simulation and measured data; bistatic ISAR image reconstruction based on ISAR is put forward after the projection of center of rotation and the angular velocity estimation method, the antenna unit projection imaging The geometric relationship between the solution space alignment problem of echo data, so as to realize the ISAR image reconstruction of each receiving unit in the same space coordinates; finally, the reconstruction of ISAR image based on the received coherent signal processing, realize the distributed coherent ISAR high resolution image fusion, and verify the effectiveness of the method through the simulation result shows that the proposed method can provide high resolution information for target recognition.

【學位授予單位】：北京理工大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：TN957.52

【參考文獻】

相關期刊論文 前3條

1 張亞標;朱振波;湯子躍;苑秉成;;雙站逆合成孔徑雷達成像理論研究[J];電子與信息學報;2006年06期

2 朱仁飛;張群;羅迎;朱小鵬;;含旋轉部件目標雙基地ISAR微動特征提取及成像研究[J];電子與信息學報;2010年10期

3 陳根華;陳伯孝;楊明磊;;分布式相參陣列及其二維高精度方向估計[J];電子與信息學報;2012年11期

相關博士學位論文 前1條

1 朱宇濤;多通道ISAR成像技術研究[D];國防科學技術大學;2011年

本文編號：1399593