High-resolution wide-swath SAR (synthetic aperture radar) ground motion object imaging method

Abstract

The invention discloses a high-resolution wide-swath SAR (synthetic aperture radar) ground motion object imaging method based on sparse space spectrum estimation, for mainly solving the problem of vast introduced operation or spectrum component gain loss when an object speed is estimated by use of a conventional method. The method is realized by the following steps: 1, performing orientation Fourier transformation on echo signals; 2, according to a sparse space spectrum estimation method, obtaining a speed of a motion object by use of echo signals of a certain Doppler unit through estimation; 3, according to the estimated object speed, obtaining non-fuzzy signals of the object; and 4, according to the estimated object speed, carrying out conventional high-resolution motion object imaging on the non-fuzzy signals. According to the invention, a motion object speed estimation problem is converted into a sparse space spectrum estimation problem, the speed of the motion object can be accurately estimated simply through a quite small operation amount, accurate reconstruction of a Doppler frequency spectrum of the motion object is guaranteed, and high-resolution wide-swath motion object SAR imaging is realized.

Description

technical field [0001] The invention belongs to the technical field of radar, and further relates to a high-resolution wide swath synthetic aperture radar (Synthetic Aperture Radar, SAR) ground moving target imaging method in the technical field of radar imaging. Background technique [0002] Synthetic aperture radar has been widely used in military and civil fields such as strategic defense, terrain mapping, etc. Among them, the use of SAR to obtain the imaging results of moving targets has become one of the research hotspots of modern radar. [0003] At the same time, achieving high-resolution and wide swath imaging is the pursuit goal of radar imaging technology. However, the traditional spaceborne SAR system is limited by the minimum antenna area and cannot acquire high-resolution wide swath images at the same time. Combined with digital beamforming technology, azimuth multi-channel SAR system can overcome this limitation by transmitting low pulse repetition frequency ...

AI Technical Summary

Problems solved by technology

Yang and Zhang et al. assumed that the spectral component of the moving target is located in the middle of the clutter spectral component, and correctly constrained the spectral component of the moving target as much as possible. Although this method can avoid heavy search operations, when the moving direction of the moving target deviates from the guiding direction, the The method will not be able to correctly constrain the spectral components of the moving target, so that the fuzzy component cannot be suppressed and cause the loss of the moving target gain

Images