Tests of the Accuracy of Indications by ARPA and AIS of the Opposite Vessel True Course, True Speed and CPA

According to the IMO recommendation when both the target data from radar tracking and AIS data are available and the association criteria are fulfilled, i.e. the radar and AIS information is considered as one physical target, then only the AIS target symbol and the alphanumerical AIS target data should be automatically selected and displayed as a default condition in radar equipment. The article presents research conducted on the reliability of data presented by the ship's AIS and ARPA regarding the true course, true speed and passing distance of the opposite vessel equipped with AIS and tracked by radar equipment in real sea conditions.