The random facet physics model is adopted to develop the water wave scattering theory that is used to calculate distributions of the diffusely reflected light from rough air-water surfaces. The depolarization is discussed in detail, which shows that the water surface diffused light is partly depolarized in all direction except the back. For a solid matter surface with strong roughness, even in the back- scattered light, the depolarized component occupies an obvious part. When the local incidence angle (Theta) i satisfies the Brewsterr condition for pure water, the scattered light is line polarized, only the S polarized component can be observed at this direction. In the polluted water case, or something is floating on the water, the received light is partly polarized or even unpolarized at the same direction. These differences suggest us to arbitrate water contamination qualitatively by realizing the received light depolarization.
"Optical method for water pollution remote sensing", Proc. SPIE 3504, Optical Remote Sensing for Industry and Environmental Monitoring, (19 August 1998); doi: 10.1117/12.319518; https://doi.org/10.1117/12.319518