US Patent 9511842 Tracking and checking compliance of vessels

There are disclosed arrangements for tracking ships and other vessels to provide best estimate of vessel track, which can be used, for example, as part of a vessel compliance process or tool. Coordinate messages from different types of transceivers (AIS, L-band, etc.), located on board a vessel are used. A confidence level may be assigned to each coordinate message dependent on the identity of the indicated transceiver, the indicated geographical position, and other factors. Measures of performance of the transceivers may be generated and used in coordinating transceiver control.