The AIS (Automatic identification system) is used (under international law) by naval vessels to broadcast and track their position on the water, to avoid collisions and aid search and rescue. The transponders on each vessel broadcast data that is detected by land based AIS stations and satellites. It turns out some AIS ground stations have been picking up phantom warships from different countries in places where they shouldn't be, the waters of other sovereign nations.
Analysts from non-profits Sky Truth and Global Fishing Watch have identified data markers that point towards these false AIS records, and have also verified the lack of physical presence of some of these phantom warships using satellite imagery, some of which were supposed to be off the coast of Cork.
