The use of synthetic aperture radar to detect and chart submerged navigation hazards

This report discusses the utility of synthetic aperture radar (SAR) data collected by the SEASAT satellite for the detection and charting of bottom features which might be hazardous to navigation. Data from 35 SEASAT orbits were used to examine nine test sites. These test sites included: the Tongue of the Ocean, Bermuda, Haiti, Sula Sgier, Cook Inlet (Alaska), the Mississippi River Delta, the English Channel, the Nantucket Shoals, and the northeast Atlantic Ocean. The northeast Atlantic test site actually contained 17 distinct bottom features such as seamounts, submarine ridges, banks and the edges of continental shelfs. Three distinct techniques were used to examine the SEASAT SAR imagery: broad survey studies, multi-temporal analyses, and multisensor analyses. This study continued to document the utility of SEASAT SAR imagery for locating and identifying bottom features in both shallow and deep water portions of the world's oceans. By correlating the SAR data with ancillary environmental data (such as wind, wave, and tidal current information) the causes of many of the bottom-related surface patterns on the SAR imagery have been identified, an important step for defining the limitations of SAR data for bottom feature detection.