Redistribution of Optical Radiation Energy when Reflecting in a Turbulent Atmosphere

Abstract

Calculation results are presented which show how optical radiation energy is redistributed and the law of conservation of energy is fulfilled when radiation is reflected from a specular surface in a turbulent atmosphere. We have ascertained that if spatially limited light beams are formed due to reflection, then the energy is redistributed in a plane transversal to the light propagation direction near the strictly backward direction within a limited region no larger than several Fresnel zones. In the case of a point reflector, where a spatially unlimited reflected wave is generated, the energy redistribution occurs on a much larger scale. An increase in the mean intensity of a reflected wave within a limited region with a diameter of two Fresnel zones around the strictly backward propagation direction (backscatter enhancement effect) occurs due to the outflow of reflected wave energy in lateral directions from a huge domain, which is several orders of magnitude larger than the area where this energy is accumulated.