Commercial satellites can get 30cm resolution images (military satellites can likely get even more high resolution). The earth is vast, but once you pinpoint a

Commercial satellites can get 30cm resolution images (military satellites can likely get even more high resolution). The earth is vast, but once you pinpoint a carrier, a simple software loop should be able to track it for ever (those carrier do not move fast). I cannot imagine this being remotely difficult for a state to have a constant pin on every large carriers sailing on earth. There even might be some civilian apps for that too. But again, Strava and other connected + geolocation apps have been an issue for military personnel in general.