AIS has a 50ms window to transmit data on just 2 channels(69,70). Not much of a problem when there are only a few ships in a few miles radius. But in a congeste

AIS has a 50ms window to transmit data on just 2 channels(69,70). Not much of a problem when there are only a few ships in a few miles radius. But in a congested harbor transmitters may never get that window in a timely manner. I've experienced cargo ships popping up out of nowhere in AIS (I could see them on radar) in Valleta harbor. A proper AP will have to ingest information from all sources (vision, sound, radar, AIS) to be able to work outside of the low traffic areas.