>>9544884 Mysterious GPS signals reveal Ghost Ships sailing in wide circles off the coast of San Francisco, despite tracking data saying they should actually be thousands of miles away
Moar from the article it seems this ships are doing it intentionally to evade tracking where they are, makes you wonder why, ehh?
Almost all ships are legally required to use an automatic identification systems (AIS) to track their location to help avoid collisions with other ships and ensure international laws are observed.
According to Bergman, there are a number of possible explanations, but no clear answer as to what's causing the strange phenomenon.
Bergman suggested it could be related to a US Coast Guard site on Point Reyes, tha that been operational until 2015.
'One thing that could be plausible is that it's acting as a zero location because of the importance of this spot in developing maritime navigation systems,' Bergman told Newsweek.
'So if [a ship's] reception is blocked for whatever reason they're appearing there.'
A likelier explanation, according to Todd Humphreys, an associate professor of Aerospace Engineering and Engineering Mechanics at the University of Texas at Austin, is that the ships are using GPS spoofing devices to trick the AIS system and mask their real location.
Humphreys told Newsweek, that the circular patterns are similar to those produced by 'off-the-shelf spoofing devices' that are commonly used to trick GPS systems.
'We know it's GPS spoofing because we also see it in the data from exercise apps,' Humphreys told Newsweek.
'Usually the false location is near the true one, but in other cases it's half a world away, like Point Reyes for a ship off the coast of Africa.'