| Synthetic ApertureRadar (SAR) is a special type of active microwave sensor. Withthe ability of generating fineresolution images from long stand off ranges, either day ornight,SAR has got a wide range of applications and plays an important role in earthobservation, environment monitor, disaster predication and military reconnaissancefields.The use of multiple antennasfor SAR is referred to as multichannel SAR andoffers the additional abilities to perform heightestimation of the ground, improve theresolution, providewide swathand suppress backscatter and/or undesiredinterferences.The informationacquisitioncapability of SAR will reduce greatly in thecomplicated electromagnetic envirnoment. SAR ECCM is a key factor in the reliabilityofSAR system. With the SAR ECCM as the background, this dissertation focusesonfour crucial techniques:radio frequency interference (RFI) suppressiontechniques,SAR ECCM techniques for active blanket jamming, SAR ECCM techniques for activedeceptive jamming, SAR ECCM effectiveness measure.Chapter1illustrates the background and significance of this research subject，andintroduces the present research status of SARtechniques, SAR ECM techniques andSAR ECCM techniques. The major research efforts of this dissertation are alsoexplained．Chapter2studies the radio frequency interference (RFI) suppressiontechniques forSAR.Based on the RFI characteristics of high power and narrow band, some novel RFIsuppressionmethods based on eigen-decomposition is proposed. One of the methods forRFI suppression is based on the dual-north filter in the frequency domain, whichnotches the received signal and the template signal simultaneously, which minimize thecorrelation peak loss to improve the performance. Another method is a novel adaptivefiltering method based on complex empirical mode decomposition (CEMD), whichdecomposes the RFI contaminated signal into a finite and often small number ofIntrinsicMode Function (IMF), and the sum of some selected IMFcomponents is takenas reference input of adaptive filter.Last but not least, a novel singular valuedecomposition method is proposed, which decomposes the singular vectors of thereceived signal with RFI into interference subspace and signal subspace, andtheorthogonality of the two subspaces is used to suppress the RFI.Chapter3studies the SAR ECCM techniques for active blanket jamming. First,thebasic principle of the blanket jamming is introduced, and then the active blanketjamming methods are divided into direct-pathblanket jammingand scatter-wave blanketjamming. For the direct-path blanket jamming, the space/slow-time STAP based methodis studied; and for the scatter-wave blanket jamming, t the method based on the combination of Fast-time STAP and Pulse diversity is studied is studied.Chapter4studies the SAR ECCM techniques for active deceptive jamming.First,the basic principle of the deceptive jamming is introduced, and then the activedeceptive jamming methods are divided into direct-path deceptive jammingandscatter-wave deceptivejamming. For the direct-path deceptive jamming, thespace/slow-time STAP based method is studied; and for the scatter-wave deceptivejamming, the space/fast-time STAP method is studied.Chapter5studies the methods for SAR ECCM effectiveness measure. For theactive blanket jamming, the methods for ECCM effectiveness measure are divided intosubjective evaluation methods and objective evaluation methods. For the subjectiveevaluation, the improvement factor of image quality grade was introduced, and a imagequality grade evaluation criteria based method was proposed; and for the objectiveevaluation, the echoenergy based evaluation method and the image quality index basedevaluation method were proposed, and the specific evaluation indexes were given.Forthe active deceptive jamming, the subjective evaluation methods for ECCMeffectiveness measure are proposed, which is based on the correlation coefficientandEuclidean distance of SAR images.Chapter6summarizes the main work and innovations of the dissertation，and looksforward to thefuture work．... |
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