# AIS

AI-generated

The Automatic Identification System:
ships, and some aircraft and shore stations,
broadcast their identity, position, course and speed on marine VHF
at 9600 bit/s in [HDLC](../hdlc/index.html.md) frames.
Software exchanges its messages as `!AIVDM` NMEA sentences.

## References

* [AIVDM/AIVDO protocol decoding](https://gpsd.gitlab.io/gpsd/AIVDM.html) (Eric S. Raymond)
* [Automatic identification system on Wikipedia](https://en.wikipedia.org/wiki/Automatic_identification_system)