Circular and Polarimetric ISAR Imaging of Ships Using Airborne SAR Sensors

Abstract

With circular flight tracks ships can be observed over the full aspect angle range of 360° with long observation times limited only by the endurance of the aircraft. Additionally to the improved probability of detection an inverse synthetic aperture radar (ISAR) image sequence of the ships as well as a sequence of high range resolution profiles (HRRP) can be obtained. The ISAR images and HRRPs can be used for target classification and recognition purposes in a post-processing step. In the paper a generic ISAR processing chain is discussed which can be used for ISAR imaging and HRRP generation for arbitrary radar platform flight tracks. Furthermore, polarimetric ISAR imaging results of a controlled police ship and of ships of opportunity are presented. The used fully polarimetric X- and L-band radar data were simultaneously acquired with DLR's airborne sensor F-SAR \cite{Reigber_2013} during a North Sea flight campaign in 2016.