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Ship detection with high-frequency phased-array and direction-finding radar systems

This paper addresses the application of HF radar systems to the detection and monitoring of shipping activity. The presence of ships within HF radar swaths often hinders the use of the data for the measurement of ocean surface currents. Data collected south of Chesapeake Bay mouth during the third Chesapeake Outfall Plume Experiment (COPE-3) this past fall from both CODAR SeaSonde and multifrequency HF radar systems illustrate the presence of large tanker ships. Comparisons of data from both sets of radar instruments with ancillary observations illustrate the ability of high-frequency radar to detect and track ships within a near coastal region. An approach is suggested to remove the ship echoes from multifrequency HF radar data. Tanker ship radar cross sections are measured to be in the range of 40 dB to 60 dBsm based on a comparison of ship echo power to ocean echo power in the Bragg region.