Redistribution of optical radiation energy along paths with reflection in a turbulent atmosphere
V.A. Banakh, A.V. Falits, I.V. Zaloznaya
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: turbulent atmosphere, reflection, backscatter amplification, forward and backward wave intensity correlation, energy conservation law
Abstract
The results of calculations are presented showing how the energy is redistributed and the law of conservation of energy is fulfilled when optical radiation is reflected from mirror surface in a turbulent atmosphere. It is shown that if, as a result of reflection, spatially limited beams of light are formed, then the redistribution of energy in a plane transverse to the direction of propagation occurs near the strictly backward direction in a limited region, the dimensions of which do not exceed several Fresnel zones. In the case of a point reflector, when a spatially unlimited reflected wave is formed, the redistribution of energy occurs on a much larger scale. The increase in the mean intensity of the reflected wave in a limited area with a diameter of two Fresnel zones around the strictly backward direction (backscatter amplification effect) occurs due to the outflow of part of the energy of the reflected wave from the lateral directions from a huge area, several orders of magnitude larger than the area where this energy is accumulated.
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