An Efficient Mehod for Low Altitude Multi-Target Imaging in Presence of Sea Clutter by the Inverse Synthetic Aperture Radar (ISAR)

Multi-target ISAR imaging is one of the most important and challenging issues in radar imaging. Detection and imaging of targets at low altitudes and near the surface due to the presence of surface clutter is also a research topic in this area. If air targets are flying at low altitudes in the sea environment, the sea clutter will greatly affect the radar signals received from these targets and this problem will increase the difficulty of ISAR imaging. In this paper, that extracted from the results of a research project, an efficient algorithm is presented that can perform ISAR imaging of multiple targets at low altitude in the presence of sea clutter, despite the aforementioned challenges. In this algorithm, called target grouping, based on space-doppler adaptive processing (SDAP), the effect of sea clutter is reduced and then by compensating the translational motion of each target group, its image is formed. Target clustering (grouping) based on the similarity of translational motion parameters and image formation of each group in a frame are the most important parts of this algorithm. The results of software implementation and simulation show that it is possible to effectively reduce the effect of sea clutter using the SDAP method and successfully form a group image of targets in clusters with the proposed algorithm. This result is very important in practical issues such as detection and identification of air targets in the sea environment.