Research On Forward-looking Superresolution Imaging Method Of Airborne Array Radar

Airborne radar forward-looking imaging has great application value in fighter reconnaissance,material airdrop and autonomous landing.Previously,the forward-looking image was mainly obtained by the real beam imaging method,but its azimuth resolution was limited by the size of the array antenna and could not meet the requirements of practical application.The introduction of superresolution imaging technology can solve the problem that the resolution depends on the size of array antenna,and obtain high azimuth resolution.In order to further improve the azimuth resolution of radar forward-looking imaging and reduce the amount of system calculation,this paper studies the forward-looking imaging based on beam-space MUSIC algorithm and uniform circular array.The specific research work of this paper includes the following points:1.The basic model of array signal is studied and analyzed.The radar array models with different array elements are obtained by studying the theory of uniform linear array and uniform circular array;MUSIC algorithm and estimating signal parameter via rotational invariance techniques(ESPRIT)algorithm of array signal processing are studied and analyzed,and their performance is analyzed.2.The forward-looking imaging model of the airborne array radar is studied.The geometric relationship of the array radar imaging is used to obtain the data matrix of the echo of the point target.The idea of array signal processing is introduced and the data matrix is analyzed,which is the forward-looking view of the airborne array radar.Imaging provides a theoretical basis.3.This paper presents an array radar imaging method based on beam-space MUSIC algorithm.Firstly,the geometric model of forward-looking imaging of two-dimensional array radar is established,and the matrix form of array output signal is obtained.The autocorrelation matrix of the modified received data is modified,and the forward and backward spatial smoothing(FBSS)algorithm is used to decorrelate the array at the same time.Secondly,the MUSIC algorithm based on beam space is introduced to study,the corresponding noise subspace and signal subspace are obtained,and then the spectrum is estimated and accumulated to obtain the image.Thirdly,the simulation experiment is carried out.First of all,the simulation results show that the algorithm can identify multiple targets in the same beam.In addition,the high-resolution performance is verified from the perspective of area target and image simulation imaging.Finally,repeated experiments are carried out for many times,and the average operation time of the system is less than that of other algorithms,which reduces the amount of system operation and improves the operation efficiency.4.This paper presents a forward-looking imaging method of array radar based on uniform circular array.Firstly,the array radar signal model based on uniform circular array is constructed,and the uniform circular array is transformed into virtual linear array,and the covariance matrix is obtained;Then the double circular array is used for decoherence,and the canonical correlation technique is used to solve the number of signal sources,and the noise and signal subspace are obtained.Finally,the spatial spectrum is estimated and the image is accumulated.This method verifies that multiple targets can be identified in the same beam,and makes a comparative analysis with other imaging methods.From the subjective analysis and objective evaluation.At the same time,the subjective analysis and objective evaluation verify that the imaging resolution of the algorithm is significantly improved.