Exploitation of very long dwell spaceborne SAR data for enhanced maritime situational awareness via ISAR approaches

This paper explores the potential of long-dwell spaceborne SAR for maritime situational awareness. Motion-induced blurring in SAR images is exacerbated during long apertures, where ships may undergo complex motions such as acceleration or rotation, making their characterization harder. To overcome this issue, this work proposes sub-aperture refocusing followed by image fusion. This includes registration and selection of a proper sub-set of images based on the estimation of the instantaneous ship centreline. The approach is tested using very long dwell SAR data, showing its effectiveness to observe fine structural details.