Plausibility analysis of navigation related AIS parameter based on time series

In this paper we study the plausibility of navigation relevant AIS parameter based on time series analysis of HELCOM AIS data, obtained during September 2011. Previous analysis [1] of AIS data sets were mainly based on studies of not known or not existent (default) values in the AIS messages. The results of these studies have shown that especially true heading (THDG) and rate of turn (ROT) parameters were strongly affected by default / unknown values. We discuss algorithms to evaluate the plausibility of data contained in the AIS message for dynamic data, like time, position, speed, and course. The contained information is checked against the plausibility of their values according to other parameters in the time series. For example the speed can be calculated from the two position information from the AIS message and the time difference between these positions. The dynamic data is consistent in this case when both the calculated and the measured value are similar within an appropriate limit. For static data the determination of plausibility is based on checks against the AIS specification. The obtained results will serve as error model for the development of a maritime traffic situation assessment facility, where AIS, radar and specific PNT data shall be fused together to create a reliable traffic situation image.