Visual Tool for Extracting Anomalous Approaches of Moving Objects

The analysis of incidents is important for preventing collisions between moving objects. However, it requires that many cases of incidents be collected as target data. The purpose of this study was to develop a method that supports the collection of many cases of anomalous (near-miss) approach from massive movement data. To achieve this, a relative superposition method is proposed. Relative superposition is a type of visualization method, in which the trajectories of pairs of moving objects are transformed, focusing on their relative positional relationships. The method is expected to facilitate the search for anomalous approach cases. This paper describes five types of relative superposition, together with a visual tool in which they are implemented. Moreover, it presents a case study in which anomalous approach cases of ships were searched by applying the tool to actual the automatic identification system (AIS) data.