Research On Inverse Synthetic Aperture Radar Imaging Algorithm Based On Compressed Sensing

Inverse Synthetic Aperture Radar can provide high-resolution images in all time, long-distance even in extreme weather conditions, and then improve the ability to identify and extract the target; Inverse Synthetic Aperture Radar in the military and civilian aspects have a wide range of applications, its imaging algorithm has become one of the hot issues. To achieve high-resolution imaging, radar need to transmit broadband signals and increase the coherent integration time, it resulting in data acquisition, transmission and storage of data is facing tremendous pressure. Copressed sensing technology can solve the problem of the huge amount of data, in this paper, we research compressed sensing application in the inverse synthetic aperture radar, and the main work done in this article is listed as follows:(1) Discuss the chirp signal and pulse compression technology, then verify pulse compression technology can improve range resolution pulse through simulation; analyse the factors affecting the target range and corss-range resolution; summarizes the imaging algorithm about smooth and maneuvering targets.(2) On the basis of imaging based on Fourier transform, achieve the image about target in the narrowband and wideband angle.Against the restrictions imaging corner, applied window、threshold processing and polar format technology to improve the range-doppler algorithm, to verify the improved algorithm through scattering model simulation. Then achieve clear image under different angle.(3) Discuss the maneuvering target imaging problem, applied the linear time-frequency transform and the bilinear time-frequency transform, such as STFT, Gabor transform, Wigner-Ville distribution and Cohen class distributiom transformation, proposed a range instaneous Doppler imging algorithm. To verify the algorithm through the measured data, then compared the imaging results are different time-frequency transform.(4) On the basis of the motion compensation algorithm, combined with time-frequency transform, an adaptive joint time-frequency motion compensation algorithm is proposed. Through scattering model simulation can verify the algorithm. Algorithm can effiectively reduce the impact of the target due to translational imaging.(5) Research the key technologies about the compressed sensing, through the one –dimensional signal and two- dimensional reconstruction to proof the OMP algorithm can reconstruct the signal. Establish the imaging model based on the compressed sensing, and then put forward an inverse synthetic aperture radar algorithm based on compressed sensing. To imaging the smooth and maneuvering targets to verify the algorithm, and get be better, finally using the algorithm to image the radar measured data then get clear imaging results.