Mapping Dark Shipping Zones Using Multi-Temporal SAR and AIS Data for Maritime Domain Awareness

The monitoring of ships which do not report their Au-tomatic Identification System (AIS) information is important for Maritime Domain Awareness (MDA). In this paper, an improved maritime picture is generated by presenting a new methodology to map these so-called ‘dark’ ships over time. Firstly, a robust and accurate data association between Syn-thetic Aperture Radar (SAR) ship detections and AIS data is carried out on multi-temporal SAR imagery and AIS data. Subsequently, Kernel Density Estimation (KDE) is applied to unassigned SAR ship detections to reveal the spatial distri-bution of ‘dark’ zones (i.e. areas where repeated unassign-ments occur). This analysis helps identify areas where ships frequently do not report, which can help guide authorities in the best way to respond. The methodology is validated using Sentinel-l Interferometric Wide (IW) swath mode products and AIS data acquired from the English Channel, UK.