a shot in the dark

AIS tracking partnership Global Fishing Watch has expanded its reach with what it believes to be the first ever publicly-available worldwide map of “undetected dark fleets” – vessels that do not broadcast AIS.

Using synthetic aperture radar (SAR) data from the European Space Agency’s Sentinel-1 satellites, coupled with machine learning algorithms, Global Fishing Watch has figured out how to automatically track vessels without the use of satellite AIS. By analyzing the entire archive of Sentinel-1 radar imagery, Global Fishing Watch has isolated 20 million data points showing the movements of sea-going vessels over about 30 feet in length. It matched up these radar returns to 100 billion GPS position data points from vessels broadcasting their position over AIS. By correlating the two, the NGO’s system is able to track many vessels even after they “go dark” and attempt to evade detection. Read on.