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Study On Active Deception ECCM In Multiple-radar Systems

Posted on:2020-04-27Degree:DoctorType:Dissertation
Country:ChinaCandidate:Q LiFull Text:PDF
GTID:1368330602963864Subject:Signal and Information Processing
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As an efficient means of Radar Electronic Countermeasure(ECM),active deception jamming has been playing an increasing important role in the modern wars.Effective means of Electronic Counter-Countermeasure(ECCM)will directly affect the normal operation and survival of radar,and even the course of wars.Benefitting from the construction features and information fusion technology,multiple-radar systems can perceive the environment from multiple perspectives and multi-dimensions,extracting more comprehensive and essential features of targets and jamming,thus having incomparable advantages over mono-static radar in countering active deception jamming.Supported by National Defense Basic Scientific Research ‘XXX ECCM techniques',the author studies the active deception ECCM methods for multiple-radar architectures based on data fusion and signal fusion.The main works of this dissertation are as following:· Study on the deception ECCM based on data fusion with a multi-static radar system.In a multi-static radar system,the receivers working ‘silently',it is difficult for the jammer to generate the active false targets with coordinated position and velocity for the whole radar system.The available deception ECCM based on data fusion,making only use of the location information to discriminate the false targets by data association,can not discriminate the false targets effectively with range-velocity joint deception.In view of the problem,according to the spatial correlation difference of the velocity information between physical and active false targets,a data association method based on the velocity information is proposed firstly to discriminate physical and false targets.Taking the Mahalanobis distance between the target velocity vectors as the discrimination statistic,the method performs chi-square test to discriminate physical and false targets.The method needs to compute the covariance matrix of velocity difference vector,which has a large computation.In view of the problem,a discrimination method is proposed based on the deception velocity judgment with less calculation.Combining the proposed method with the one based on position information,multi-static radar systems can obtain a better discrimination performance for false target with range and velocity joint deception,and extend the high discrimination area of the active false target.· Study on the deception ECCM based on signal fusion for a distributed multiple-radar architecture with two transmitters and multiple receivers.In a distributed multiple-radar architecture,the spatial scattering properties of targets can be utilized to counter active deception jamming effectively.When the cooperative detection is performed,the available method to discriminate active false targets needs to know the precise jammer location,and its performance will suffer significant deterioration with little location error.Aiming at the problem,the dissertation studies on the active false target discrimination method for a distributed multiple-radar architecture with two transmitters and multiple receivers.The difference in spatial scattering property makes the Hermitian distance of a false target considerably different from that of a physical target.The Hermitian distance of a false target increases with the raise of jamming-to-noise ratio,whereas the one of a physical target obeys an identical Beta distribution for all signal-to-noise ratios,which leads to the former much greater than the latter,especially in high jamming-to-noise ratio.Making full use of the difference,a novel method is proposed based on the Neyman-Pearson lemma to discriminate physical and active false targets.The proposed method overcomes the dependence of the available method on the prior information about the jamming environment.What's more,the proposed method can keep a constant misjudgement probability for physical targets and discriminate targets effectively in one pulse repetition interval.· Study on the deception ECCM based on signal fusion for a distributed multiple-radar architecture with multiple active false targets.The method based on Hermitian distance is only applicable to a multiple-radar system with at least two transmitting stations.In a multiple-radar architecture,the Hermitian distance between the sample vectors of two targets is taken as the correlation metric to measure the mutual correlation property between the two targets.The difference in spatial scattering property leads to the difference in the correlation of different target combinations.The correlation between two false targets is much greater than that between two physical targets or that between a physical target and a false target,especially in high jamming-to-noise ratio.The correlation between two false targets increase with jamming-to-noise ratio,and is independent of the modulation of false targets.Whereas,the correlation between two physical targets and the one between a physical target and false target obey an identical Beta distribution which has nothing to do with signal or jamming power but the channel number.Based on the difference,hypothesis testing is performed based on correlation test to discriminate false targets.The proposed method does not require any prior information about the jamming environment and can discriminate the targets effectively in one pulse repetition interval.Moreover,the proposed method can restrict the upper bound of the misjudgement probability for physical targets,and performs better with more active false targets.· Study on the deception ECCM for multiple-radar systems with wide-band signal.The existing deception ECCM based on signal fusion are derived under the assumption that the transmitted signal is a narrow-band signal,thus they are not suitable or can not be applied directly to the cases with wide-band signal.In the multiple-radar system with wide-band signal,the difference between physical and false targets on the spatial scattering property still exists,which can be utilized into targets discrimination.When the transmitted signal is a wide-band signal,the size of the target is larger than the range resolution cell of the radar.Therefore,the target will occupy several range resolution cells.The complex amplitude of the range resolution cells occupied by the target is named as complex range profile vector,and the correlation between the complex range profile vectors of different target combinations between different receivers is analyzed.Considering that the length of the target range profile varies with the change of the view angle,sliding Hermitian distance is introduced,and sliding Hermitian distance of complex range profile vectors in different receivers is analyzed.The correlation coefficient between two targets is defined as the maximum sliding Hermitian distance of their complex range profile vectors.Through theoretical analysis,it is found that the correlation of the same active false target in different receivers is significantly greater than that of other target combinations.Making use of the difference,a discrimination method is proposed based on correlation test for multiple-radar systems with wide-band signal.The method can constrain the physical target misjudgment probability,and the simulations verify the feasibility and validity of the proposed discrimination method.
Keywords/Search Tags:distributed multiple-radar architecture, deception electronic counter-countermeasure, data fusion, signal fusion, spatial scattering property, Hermitian distance, Beta distribution, active false target discrimination, wide-band radar, correlation test
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