VARIABLE ATMOSPHERE EFFECTS ON HIGH ENERGY LASER PROPAGATION

Propagation of high energy laser beams to space has previously been evaluated on the basis of constant, seasonally averaged standard atmospheres, time constant levels of turbulence with the appropriate altitude profile, and time constant winds in direction and velocity, independent of altitude. In actually, atmospheric conditions are highly variable resulting in a large spread in propagation performance as a function of time. The purpose of this paper is to develop a methodology for determining the propagation performance on an annual probability basis, and to give an example of the use of this methodology. Particular emphasis is addressed to the statistical modeling of thermal blooming, a nonlinear absorption phenomenon that limits the maximum amount of propagated laser power