A system trade model for the monitoring of coastal vessels using HF surface wave radar and ship automatic identification systems (AIS)

Coastal nations have an interest in maritime domain awareness for applications in national security, coastal conservancy, fishery and stewardship of the exclusive economic zones (EEZs) along their coastlines. Using our previously developed HF radar and AIS ship detection models we find signal to noise ratio (SNR) as a function of range, including ducted propagation for the AIS radio signals. We use these SNR estimates to find probability of detection P_d and then explore multiple systems and stations at variable spacings along the coast. Our example HF radar has significant power and aperture, similar to the Pisces radar. The AIS model is for high power (12.5 W) AIS and a significantly elevated receiver (≈ 250 ft asl). A combined system of HF radar and AIS shows good capability (P_d > 0.9) to ranges of ≈ 125 km for small ships and to 200 km for large ships. Considering a system of sites separated by 100 km we find that a P_d of > 0.9 can be maintained to a distance off shore of 130 km even for small, 120 ton, ships.