Sun Glints and Underwater Caustics in Remote Sensing of Seas and Oceans

Abstract

The Sun glints that are observed on the water surface have different radiances, shapes, and color shades, depending on the positions of the Sun and the observer, the water surface statement, and the transparency of the water and atmosphere. The texture, radiance, and color characteristics of Sun glints carry information about the state of the water and atmosphere. Therefore, Sun glints play an important role in remote sensing of seas and oceans, being a useful signal in some problems and noise in others. Bright stripes (underwater caustics) on the bottom of the water basin that are caused by the waves are also an indicator of the water surface shape. The application of the wave theory of light is used to study the intensity distribution in the vicinity of the caustic (i. e., where the geometric-optical approximation is inapplicable), which arises when light is refracted on a wavy water surface.A formula, which determines the parameters of the waves from the width of the caustic zone is obtained. The correctness of the method has been verified by experiments carried out in the pool. Also, here we give a brief overview of our investigations related to sun glints and underwater caustics.