Monitoring of Coastal Vessels Using Surface Wave HF Radars: Multiple Frequency, Multiple Site and Multiple Antenna Considerations

Marine situational awareness is a key factor in coastal activities, e.g. national security (terrorism, drug smuggling, etc.) and environmental protection (marine protected areas, fishery monitoring and regulation, oil spills, etc.). HF surface wave radar is a strong candidate to become a component of any large area, vessel-monitoring network. We discuss estimating the primary metrics for assessing performance for ship tracking radars (probabilities of detection P_d and false alarm P_fa) and their variation with parameters, such as range, azimuth and frequency, and number of observing modes. We discuss several design options for an HF radar, ship monitoring system, such as multiple or single frequency, multiple or single sites or method of target bearing determination (MUSIC or real aperture antenna) and present a model of the SNR for ship detection by HF radar and as well as observational examples of ship detection with single and multifrequency HF radars. Finally we suggest future experiments and draw conclusions.