Remote Sensing of Sea State by the Brewsters Angle Technique

Abstract

The extent of plane polarised light resulting from Brewsters reflection from the wide-roughened sea surface is studied for various sea states on the assumption that the incident light on the air-sea interface is unpolarised. The sea states associated with different wind speeds are simulated using the Cox and Munk 'wind speed-wave slope' law and the Gaussian distribution of wave-slopes. The spatial distribution of plane polarised component of diffuse reflected light is also studied with a view to exploring possibilities of using this parameter for remote sensing of sea state from a sensor viewing the sea surface through an appropriate polaroid. The results show that the plane polarised fraction of reflected light as received in a given look angle can be directly related to the prevailing sea state and can be used as a convenient parameter for remote sensing of sea state. The scope and limitations of the method proposed are discussed.