The Anti-Jamming Method For Digital Array Radar Seeker

In modern warfare,the mode of warfare has been transformed from fire suppression to precision targeting.As a result,missiles are increasingly playing an important role in military.When radar seeker detects a target,it is often interfered by human,which makes it unable to track the target accurately.Therefore,the radar seeker needs strong anti-jamming ability.Digital array radar is characterized by its realization of electrical scanning,ultra-low sidelobe receiving,multi-beam receiving and large degree of freedom in space.In this thesis,the anti-jamming method based on digital array seeker is studied.At present,intelligent anti-jamming technology based on interference perception has become an important direction of anti-jamming.First,the technology perceives the interference environment,and then it adjusts confrontation strategy according to the change of the interference environment.Because of the closed-loop response to interference is realized,the optimal anti-jamming effect can be achieved.This thesis particularly demonstrates the performance of the closed-loop anti-jamming method based on jamming perception in the process of airspace countermeasures.First,the array signal model and the possible signal model appears in airspace confrontation is introduced.And then,the received signal data is processed to suppress the interference and obtain the desired signal.First of all,it is necessary to estimate the perception and angle of suppressed jamming.When estimating the angle of suppressed jamming,in this thesis,super-resolution algorithm is used to break through Rayleigh Limit constraint and improve angle resolution by spatial spectrum estimation technology,so that radar can distinguish two or more jamming signals in one beam width.On the suppression of main lobe interference,through the design of blocking matrix,this thesis improved the blocking matrix preprocessing(BMP)algorithm,which made the radar overcome the main lobe distortion,beam pointing offset and sidelobe level rise while suppressing the main lobe interference signal.Compared with the traditional BMP algorithm,the improved algorithm greatly reduces the energy loss on useful signals by changing the elimination interval of array elements and the radar aperture completion algorithm.Furthermore,the subsequent detection probability is greatly improved and the angle measurement error is greatly reduced.Then,aiming at the perception problem of deceptive jamming,the signal suppressed by suppressive jamming is measured by sum-difference amplitude comparison.The angular glint phenomenon is judged by N times of angular measurement results,and then the existence of deceptive jamming is judged.Finally,based on the amplitude and phase errors,the effects of the amplitude and phase errors of element channels on the simulation results are analyzed in this thesis.Through computer simulation experiment,the effectiveness of the anti-interference method proposed in this paper for digital array seeker is verified,which provides a new feasible measurement for digital array seeker to resist compression interference and spoofing interference,and lays a good theoretical foundation for its engineering implementation.