Estimation of the rotation angle by phase slope for ISAR imaging

In order to compensate the image blurring induced by target rotation in inverse synthetic aperture radar (ISAR) imaging, a novel method is proposed to estimate the rotation angle by accumulating the phase difference in cross-range direction between two dominant scatterers extracted in the range-Doppler (RD) ISAR image. Firstly, two dominant scatterers are extracted in the RD image by the statistical CLEAN technique. Then based on the phase difference slope of the two dominant scatterers accumulated in cross-range direction, the phase rotation rate is estimated. Finally, the compensation of the rotation angle is done before RD imaging. A set of real ISAR data is used to verify the effectiveness of the proposed method.