Predicting the capabilities of ship monitoring by HF radar in coastal regions

Maritime domain awareness is important for coastal nations in terms of applications to coastal conservancy, security, fishery and stewardship of their exclusive economic zones (EEZs). Maritime situational awareness involves knowing the location, speed and bearing of ships and boats in the EEZ. HF radar is a useful tool in providing ship information in real time. It is especially effective when combined with information from ship-borne AIS beacons. It is important to be able to simulate HF radar (as well as AIS) performance in a ship-monitoring role, so that the cost-effectiveness of a network of HF radars and AIS beacon receivers can be estimated. A good performance simulation model also allows design trade studies that lead to effective and efficient system design. We describe a radar performance simulation model based on well-known principles and specialized to the Codar SeaSonde HF radar as installed at the Pescadero California station in the California Ocean Current Monitoring Program (COCMP). We include a parameter to account for the loss in propagation across the land-sea transition as well as coupling HF radar waves between antennas and the ground wave propagation mode. We compare performance simulation results in terms of signal to noise ratio with radar observations of ships by the Pescadero HF radar station. We find good qualitative agreement in terms of the ranges at which ships are detected and not detected.