AIS signal radiolocation, tracking and verification

In the framework of cooperative sensors the Automatic Identification System (AIS) has an important role as AIS transponders are operational on majority large number of vessels. AIS has been originally conceived for collision avoidance and is a system whereby ships broadcast their presence, identification and location. Differently than other operational coastal active systems for maritime surveillance, AIS is characterised by a considerable terrestrial coverage (VHF propagation) together with a relatively accurate positioning (GNSS) performance [1]. The recent increase of terrestrial networks and satellite constellations of receivers is providing global tracking data that enable a wide spectrum of applications beyond collision avoidance. The central role of AIS has been recognised by international regulations. Ships of 300 gross tons and upwards in international voyages, 500 tons and upwards for cargoes not in international waters and passenger vessels are obliged to be fitted with AIS equipment as regulated by the IMO Safety of life and sea (SOLAS) [2]. Furthermore, all EU fishing vessels of overall length exceeding 15 m are also required to be fitted with AIS from May 2014 [3].