Satellite Interferometry for Ocean Surveillance

A system employing satellite-borne interferometry to provide cooperative monitoring and surveillance of ocean vessels at low cost to the user is proposed in this paper. L-band signals transmitted by a vessel are received at a geostationary satellite equipped with a crossed-boom, long baseline interferometer pair. The signals received at each interferometer element are translated to an appropriate downlink frequency (e.g. C-band) and are FDMA downlinked to a shore station for processing. The shore station extracts position, vessel ID, and mission-related data from the received signals. Signals from four calibration stations of known position are continually monitored for attitude correction and compensation of thermal deflections of the booms. A high accuracy (0.5 km ) position update can be obtained with 90% probability for each of 3000 vessels every 6 min.