Big maritime data for the Baltic Sea with a focus on the winter navigation system

The automatic identification system (AIS) has become a key element in maritime domains of inquiry and the number of related articles has increased rapidly. The systematic integration of AIS data with other datatypes has received less attention and has mostly resulted in application-specific datasets that are small relative to the available AIS data. This work presents an accumulating multi-purpose database for the northern Baltic Sea that combines nine years of AIS data with marine environmental data. The main application is winter navigation research, for which purpose the environmental data is from ice charts and ice drift models. The AIS data is from terrestrial stations and amounts to 6 billion messages. It has a full update rate which is also required for the analysis of ice navigation as this involves close encounters, icebreaker assistance, convoy operations, and rapid speed changes. To identify and study such traffic features, distances between ships that are close to each other are included in the database. Application examples are given for spatial traffic statistics, reduction of ship speed with increasing ice thickness, and for icebreaker assistance.