Mathematical morphology for clutter removal in airborne radars

Mitigation of clutter due to sidelobe and mainlobe of antenna in airborne radars is of paramount importance for detection of moving targets. In this paper, an algorithm based on mathematical morphology is proposed to remove clutter from range - Doppler image. Clutter spread in range as well as Doppler due to motion of platform and clutter characteristics are dependent on range. The proposed algorithm extracts the clutter region without training or prior knowledge of the clutter spectrum. Morphological processing is applied on range-Doppler image to find the connected components of detections from constant false alarm rate (CFAR) processing. The identified connected components form the clutter image which is then used to remove false detections due to clutter. The proposed algorithm is compared with conventional sidelobe blanking algorithm and has shown better performance.