AIS targets still have their problems occassionally, especially if you’re not comparing against a radar or visual picture. This video shows an inbound Balsa ship (green footprint) with a magenta footprint shadowing it off to the north. That magenta footprint is what the balsa AIS transponder is transmitting to the world. The Balsa ship then meets an outbound vessel, Macondo. The real world sees a port to port meeting; anyone watching AIS sees a starboard to starboard meeting. This error has been attributed to a GPS offset issue on the Balsa ship that was subsequently corrected. The PPU software (ARINC) allows the pilot to see his own DGPS generated position and compare it to what the ship is transmitting.
Does anyone know if there any approved AIS-B units out yet?