Compressed sensing-based ground MTI with clutter rejection scheme for synthetic aperture radar

摘要

This study investigates moving target indication (MTI) and velocity estimation for the single-channel synthetic aperture radar system. A four-dimensional grid is employed for location and velocity representation of any moving targets. Clutter terms spread among all location grid cells and a small number of velocity grid cells corresponding to small velocities. Since in practical situations, clutter spectra have a certain widening in frequency, it is favourable to cancel an arbitrarily chosen number of clutter bins about zero Doppler. In this study, a subspace-based clutter rejection method is proposed to cancel the stationary ground clutter in addition to clutter up to higher Doppler frequencies. That is, after suppressing the clutter successfully, the ground MTI problem becomes sparse and a compressive sensing reconstruction algorithm is applied to solve for the location and velocity of the moving target. To reduce the amount of data storage and computational load, some undersampling schemes are done based on the ability of compressive sensing to solve the underdetermined set of equations. Finally, it is shown how the proposed clutter cancellation method is important for the high data rate reduction case of undersampling.