202512 - Vessel detections from Sentinel 2

Vessel detections with Sentinel-2 satellite imagery from 2019 to 14 days ago. Multiyear detection of vessels with respective length, speed and orientation estimates based on deep-learning models applied to electro-optical imagery (RGB and near-infrared) at 10-m resolution covering most exclusive economic zones and marine protected areas across the ocean.

Sentinel-2 detections are  based on electro-optical imagery at 10-m resolution. Compared with our published Sentinel-1 detections based on SAR imagery at 20-m resolution, Sentinel-2 allows detecting smaller vessels with all types of vessel materials, in contrast with the weakness of SAR imagery on revealing vessels made of wood and fiberglass. Sentinel-2 also images the wakes of moving vessels, which further increase the detectability of small vessels and allow us to infer the vessels’ speed and orientation.The rich information contained in the optical imagery can be used to map not only vessel presence, but also vessel activities such as vessel encounters and bottom trawling. Sentinel-2 also covers more area of the ocean than Sentinel-1, and the novel neural-net detection approach does not require the exclusion of near-shore regions (as opposed to the CFAR approach), allowing detection of vessels in highly-packed areas all the way to the shoreline where most human activity is concentrated. Overall, with Sentinel-2 imagery we are able to detect about 3 times more vessels, “see” a broader range of vessel lengths and types, and infer more information of vessel activities than in our previous mapping using Sentinel-1 imagery.