Satellite‐based vessel Automatic Identification System: A feasibility and performance analysis

Abstract

SUMMARYThe Automatic Identification System (AIS) is a VHF communication system that provides identification/ location information to vessels and shore stations by exchanging data such as position, identification, course, speed, etc. Recently, the interest in detecting and tracking ships at distances from coastlines larger than what can be accomplished by normal terrestrial VHF communications has grown, driven by requirements of long-range applications such as better handling of hazardous cargo, improved security and countering illegal operations. This paper presents an extension of AIS to a long-range positioning reporting through a constellation of LEO satellites. It outlines technical challenges like the high rate of message collisions from ships in the field of view of a satellite. Technical solutions are proposed at system and subsystem level to address these challenges. A computer-based system simulator is used to assess the system performance and carry out a high-level system sizing. Results show that a relatively small constellation of LEO satellites can guarantee good ship position detection probability as well as a reporting time interval of a few hours. System performance aspects to be addressed in future work are the possible impact of terrestrial mobile communications interference as well as variations of the estimated traffic data.

A Beam Scanning Method based on the Helical Antenna for Space-based AIS

“…68 observation times, down to zero on the edge of the satellite FOV in the direction perpendicular to the satellite velocity vector (Cervera et al, 2011). Therefore, in order to achieve complete coverage and account for ship motion between adjacent ascending nodes, the footprints of the antenna in adjacent orbit passes should be overlapped with each other.…”

On the impact of coverage range on AIS message reception at flying platforms

“…A major breakthrough in the field was achieved in the mid 2000's, when several studies proved the viability of AIS message reception at Low Earth Orbit (LEO) satellites [3], [4], [5], [6], [7]. As a matter of fact, the possibility to collect navigation information at a flying platform complements the original goal of AIS, providing an overall picture of vessels distributed over large areas and enabling worldwide routes monitoring.…”

Simulating Surveillance Options for the Canadian North

“…Other examples of complications with satellite reception of AIS include loss of signal due to weak transmission power, Doppler frequency shift between transmitter and receiver, interference from terrestrial VHF systems, and Faraday rotation of waves. These and additional complications have been summarised by others (Carson-Jackson, 2012;Cervera et al, 2011).…”

“…69 2012) of how many messages have been missed, have been reported. A computer-based simulator was developed and used to predict ship/message probability of detection (Cervera et al, 2011). A test bed was developed to evaluate S-AIS receivers prior to launch (Dembovskis, 2012;Re et al, 2012).…”