Mapping AIS coverage for trusted surveillance

Abstract

Automatic Identification System (AIS) is an unattended vessel reporting system developed for collision avoidance. Shipboard AIS equipment automatically broadcasts vessel positional data at regular intervals. The real-time position and identity data from a vessel is received by other vessels in the area thereby assisting with local navigation. As well, AIS broadcasts are beneficial to those concerned with coastal and harbour security. Land-based AIS receiving stations can also collect the AIS broadcasts. However, reception at the land station is dependent upon the ship's position relative to the receiving station. For AIS to be used as a trusted surveillance system, the characteristics of the AIS coverage area in the vicinity of the station (or stations) should be understood. This paper presents some results of a method being investigated at DRDC Atlantic (Canada) to map the AIS coverage characteristics of a dynamic AIS reception network. The method is shown to clearly distinguish AIS reception edges from those edges caused by vessel traffic patterns. The method can also be used to identify temporal changes in the coverage area, an important characteristic for local maritime security surveillance activities. Future research using the coverage estimate technique is also proposed to support surveillance activities.

Estimating Reception Coverage Characteristics of AIS

“…The technique described here was first introduced in a recent paper (Lapinski & Isenor, 2010) that specifically focused on the benefits of using the technique. The technique described here was first introduced in a recent paper (Lapinski & Isenor, 2010) that specifically focused on the benefits of using the technique.…”

“…The working postulate is that AIS messages themselves can be used to obtain the spatial-temporal characteristics of the larger scale AIS coverage for a given geographic domain. The technique described here was first introduced in a recent paper (Lapinski & Isenor, 2010) that specifically focused on the benefits of using the technique. This paper presents the algorithm used to produce an empirical estimate of AIS coverage.…”