5 ms·

Where do they get this data from?

• wiml 7y ago
  It's probably just logging AIS data ( https://en.wikipedia.org/wiki/Automatic_Identification_System https://en.wikipedia.org/wiki/Automatic_Identification_Syste... ). Large ships are required to broadcast (like, on the radio) their position, heading, and so on. Anyone with a radio receiver can collect this data for ships within radio range. Anyone with a large number of internet-connected radio receivers can collect this data over a large area.
  • Moru 7y ago
    They often give out free receievers to spread their network
  • juskrey 7y ago
    Amateur AIS receiver networks are only covering near-shore areas, for obvious reasons. Covering deep sea/ocean areas (often the most interesting part) requires some paid subscriptions.
• w_t_payne 7y ago
  AIS receivers on satellites.
  • noselasd 7y ago
    And perhaps the international space station ? https://www.esa.int/Our_Activities/Space_Engineering_Technology/AIS_on_ISS https://www.esa.int/Our_Activities/Space_Engineering_Technol...
• Workaholic_87 7y ago
  AIS transponders are required for almost all commercial vessels