A novel method for limiting the amplitude of SAR images with the principal axis detection

Amplitude limiting of SAR target is one important preprocessing procedure in SAR target recognition. Traditional amplitude limiting adopted simple threshold value and is usually sensitive to noise. In this paper, a novel method for limiting amplitude is proposed, which is based on the priori knowledge that normally the strong scatter points are nearby target's principal axis. First, target's principal axis and its center is detected with the strong scatter points, then the target area is estimated and the strong scatter points' amplitude are limited by a simple smooth process. Experiments on SAR image show that the proposed method can limit the amplitude of the strong scatter points and enlarge that of the weak scattering points well.