THE EFFICIENCY OF THE REVERSED WAVE-FRONT FIELD WITH A PHASE-SHIFT FOCUSING IN RANDOM-MEDIA

The effectiveness of reversed wave focusing in a random atmosphere was studied by using the phase approximation of geometrical optics as well as in an oceanic waveguide using the method of normal modes and horizontal rays. Calculations were made for the turbulence fluctuation obeying a structural function with a 2/3 power law. To provide focusing of the field radiated by a point-like source into a given point, a correction phase factor, determined for a homogeneous medium, was introduced. We estimated that the size of a region near the location of the source wherein the intensity of a held, focused in accordance with the free-space algorithms, decreased due to random inhomogeneities to no less than half of its original size. The minimal number of reference sources necessary for effective focusing at any point in the region under consideration was estimated.