Ship detection and speed estimation based on azimuth scanning mode of synthetic aperture radar

A novel technique is presented for the ship detection and ship speed estimation based on the azimuth scanning mode of synthetic aperture radar. The improved Doppler beam sharpening imaging algorithm is used to produce a sequence of individual sub-images of ships in the same scan region from different aspect angles with a high revisit rate. These sub-images have an inherent property that they are formed at different discretely delayed times. The azimuth resolutions of the sub-images formed in different scan angles are discussed. The cross-correlation function of two specific sub-images, which have the same azimuth resolution, is then produced. The radar cross-section of ships is higher than the surrounding sea clutter, so that their sub-images possess a higher degree of coherence than the uncorrelated random images of the surrounding sea surface. Moreover, the speed vector of moving ships can be estimated based on the shift of the correlation peak. The processing results show the effectiveness of the algorithms.