Maritime traffic monitoring using a space-based AIS receiver》.pdfVIP

Acta Astronautica 58 (2006) 537 –549 /locate/actaastro Maritime traffic monitoring using a space-basedAIS receiver ∗ Torkild Eriksen , Gudrun HZye, BjZrn Narheim, Bente JenslZkken Meland Norwegian Defence Research Establishment, P.O. Box 25, N-2027 Kjeller, Norway Received 30 May 2005; received in revised form 25 November 2005; accepted 15 December 2005 Available online 31 March 2006 Abstract The Automatic Identification System (AIS) is a maritime safety and vessel traffic system imposed by the International Maritime Organization (IMO). The system broadcasts position reports and short messages with information about the ship and the voyage. Using frequencies in the maritime VHF band, the coverage is similar to other VHF applications, and is essentially dependent on the altitude of the antenna. For ship-to-ship communications the range is typically 20 nautical miles and for ship-to-shore up to 40 nm. A space-based AIS receiver in low earth orbit will have a range to the horizon of more than 1000 nm, giving an excellent opportunity for large-area ocean surveillance. The Norwegian Defence Research Establishment (FFI) has performed a feasibility study on reception of AIS messages from space. The results show that a ship detection probability of near 100% can be obtained for up to 1000 ships within the coverage area, and that for a standard AIS receiver a signal power margin of 10–20 dB can be achieved. On this background, swath-width analyses for European scenarios are done. It is argued that space-based reception of AIS messages is a promising way of achieving long-range identification and tracking services at marginal co