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TODO

  • Most frequent messages are types 1, 3, 4, 5, 18. We should decode all of them. Currently we decode 1, 3, 4 and 5.
  • Find out what ports' reports are. I think they announce when a ship arrives/leaves from port.
  • Found out how satellite can be used to capture all AIS.
  • Decode some Type 8 messages: 1-11, 1-31 (meteorological)
  • DONE: Decode Type 6 DAC-FIDs in order to have some stats. Though Type 6 mesages are very rare it seems.
  • DONE: Decode MMSI (includes country or other info as well)
  • DONE: Implement a generic router where we feed it messages and it returns message type and payload or error.
  • DONE: implement a parser for payloads spanning across 2 or more AIS messages. (tricky: variable length, out of order maybe, maybe we should expire if we don't receive all parts after some time)

Consider TODO

These will take much time and maybe there should be some business plan before. In any case we will retain all data, so if in the future the need arises, we can decode them then.

  • Decode some Type 8 messages: Area Notice, Extended Static and Voyage Related Data, Route Information, etc
  • Decode Type 9 messages: search and rescue aircrafts position report
  • Decode Type 12 messages: addressed safety related message
  • Decode Type 14 messages: broadcast safety related message
  • Decode Type 19 messages: Class B extended position report (something between type 18 and type 5)
  • Decode Type 21 messages: aid to navigation report
  • Decode Type 27 messages: long range Class A position reports

Notes:

  • Type 1/2/3/4/9/11/18/22 - 168bits - 1 sentence
  • Type 5 - 424bits - 2 sentences
  • Type 6/8/12/14 - up to 1008bits - up to 5 sentences
  • Type 7/13 - 72-168bits - 1 sentence
  • Type 10 - 72bits - 1 sentence
  • Type 15 - 88-160bits - 1 sentence
  • Type 16 - 96 or 144bits - 1 sentence
  • Type 17 - 80 to 816bits - up to 4 sentences
  • Type 19 - 312bits - 2 sentences
  • Type 20 - 72-160bits - 1 sentence
  • Type 21 - 272-360bits - 2 sentences
  • Type 23 - 160bits - 1 sentence
  • Type 24 - 328-336bits - 2 sentences
  • Type 25 - up to 168bits - 1 sentence
  • Type 26 - 60-1064bits - up to 5 sentences
  • Type 27 - 96 or 168bits - 1 sentence

Stats

Out of 76175 type 1, 3, 4 messages analyzed:

71162 / 76175 Ship 4344 / 76175 Coastal Station 316 / 76175 Group of ships 213 / 76175 Aids to navigation 109 / 76175 SAR —Search and Rescue Aircraft 20 / 76175 Diver's radio 01 / 76175 invalid MMSI

Out of 701088 messages analyzed:

Type 1: 218359 Type 3: 55917 Type 4: 23239 Type 5: 65672 Type 8: 272742 Type 9: 226 Type 12: 3 Type 13: 5 Type 18: 25117 Type 21: 17380 <- Aid-to-Navigation Report Type 24: 22428 <- Static Data Report