2.2. Geo-related data

We have enriched our dataset with seven GIS layers, organized in ESRI format, namely, regions, harbours, port of Piraeus, islands, territorial waters, receiver location, and spatial coverage. In the ‘regions’ layer, we have included the 13 regions of Greece, with Attica being the most notable since it covers Piraeus and the Saronic gulf islands nearby. The ‘harbours’ layer includes 14 ports, 6 marines, and 1 canal, located within the spatial coverage of the dataset; all are stored in point geometry, as illustrated by Fig. 5 (left). Especially for the port of Piraeus, which is of major importance for the usability of the dataset, we also provide its sketch in polygon format in a separate layer, as illustrated in Fig. 5 (center). The ‘islands’ and ‘territorialWaters’ layers include the polygons of 60 islands and a polygon mapping the territorial waters, respectively, in the area of interest, as Fig. 5 (right) illustrates. Regarding the last two layers, ‘receiver location’ and ‘spatial coverage’, they deal with the AIS station itself as their name declares.

Saronic gulf ‘harbours’ (left); ‘PiraeusPort’ (center); and ‘islands’ - ‘territorialWaters’ (right) GIS layers.

Table 2 summarizes the geo-related data included in our dataset. As it appears in the table, some of the information comes from open sources, namely geodata.gov.gr⁸ and OpenStreetMap.⁹

Summary of geographic-related data.