21 December 1994 Thickness characterisation of oil spills using active microwave sensors
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Oil thickness is a crucial parameter in the characterization of oil spills for environmental impact. The feasibility of using active microwave sensors to measure thickness was addressed in a series of microwave scatterometer experiments performed by Simrad Marine A/S in a wave tank at the Nansen Environmental Remote Sensing Center. The thickness of the oil layer was maintained at levels similar to the thick part of an oil spill (0.1 - 1 mm). The measurements showed the capability of active microwave sensors to measure oil spill thickness when the oil type is known. In addition to thickness characterization, the experiment studied the effects of oil viscosity, incidence angle, wind speed, wind angle, microwave frequency, and polarization. The backscatter contrast was observed to be greater for lower incidence angles which indicates that the ERS-1 viewing geometry is optimum for the detection and measurement of thick oil slicks. A thickness-dependent backscatter model was developed which included the effects of oil viscosity, composite surface effects, and oil-water reflectivities. The model viscous effects saturated when the oil thickness was greater than the viscous boundary layer thickness. This explained the observed C-VV backscatter contrast saturation for low viscosity diesel oil at thicknesses greater than 0.15 mm. The model predicted contrast saturation at greater thicknesses for the higher viscosity oils. The data showed this trend but the measurements did not extend to thicknesses which tested the model completely.
© (1994) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Michael True, Michael True, Robert A. Shuchman, Robert A. Shuchman, D. W. Kletzli, D. W. Kletzli, Johnny Andre Johannessen, Johnny Andre Johannessen, Gunar Digranes, Gunar Digranes, Sverre Berg, Sverre Berg, Kjell Dalland, Kjell Dalland, "Thickness characterisation of oil spills using active microwave sensors", Proc. SPIE 2319, Oceanic Remote Sensing and Sea Ice Monitoring, (21 December 1994); doi: 10.1117/12.197270; https://doi.org/10.1117/12.197270

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