Detecting and mapping offshore navigation hazards using synthetic aperture radar data

The 4000 offshore oil production facilities in the Gulf of Mexico and many other partially submerged structures are obstacles to navigation as well as being of commercial importance. Oil spills from these production or transportation facilities could cause extensive damage to the coastal ecosystem and an economic collapse of the fisheries industry. The same production facilities are also navigational hazards to private and commercial navigation. The risk of damage to the environment and economy is ameliorated by current accurate maps of offshore oil production facilities. National Ocean Service (NOS) Nautical Charts published by the National Oceanic and Atmospheric Administration (NOAA) map the location of navigational hazards. Oil production platforms and other navigational hazards are indicated on these NOAA charts within an accuracy tolerance of 50 meters at a scale of 1/80000. The frequency of map revision is dependent on the rate of coastal change and user needs. However, NOS Nautical Charts may not be revised for several years or even a decade because of cost. This study evaluates the potential and limitations of using airborne SAR for detecting and mapping navigation hazards, primarily offshore oil production facilities, in coastal Louisiana. However, the results are extendable to other coastal zones. Accuracy assessments indicate the importance of target and system parameters in target detection of navigational hazards