Focused ISAR images of maritime targets using a high resolution LFMCW millimeter-wave radar

The generation of high resolution ISAR (inverse synthetic aperture radar) images is reaching protagonism at the present time. A major application is coast surveillance. The recognition and the identification of maritime targets are important tasks. In this paper experimental results of ISAR images of maritime targets are reported. The data were captured with an LFMCW (linear frequency modulated continuous wave) millimeter-wave radar. High resolution ISAR images are obtained, since a great bandwidth (1 GHz) is transmitted. In ISAR the target motion can degrade the quality of the final images and motion compensation algorithms are necessary to improve the focus of these images. An autofocusing technique based on the shift-and-convolution algorithm is used to compensate the translational target motion and a two-phase algorithm (slant range rotation compensation (SRRC) and cross range rotation compensation (CRRC)) is used to correct the migration through resolution cells (MTRC) associated with the target rotation. The effectiveness of the focusing techniques is verified with simulated and real (maritime targets) radar data and compared with the standard range-Doppler algorithm (RDA)