STATBIC - A Method for Inclusion of Fractal Statistics in Obscurant Transport Models

A generic texture routine was developed for upgrading smooth obscurant cloud models by introduction of time and space dependent fluctuations in line of sight (LOS) propagation and image generation. The routine runs separately from or in conjunction with other obscuration models that predict electro-optical (EQ) propagation for mean or average aerosol concentration contributions in the obscurant cloud. Atmospheric turbulence and eddy structures are the underlying sources of concentration fluctuations. Eddy structures can possess certain well defined and statistically predictable correlations between larger and smaller eddies that are linked to the steady breakup of larger eddies and the cascade of energy to smaller eddy scales. The resulting effects of these correlations in concentration are simulated by prototype algorithms that provide either two-dimensional propagation overlays for image modification or three-dimensional volume fluctuations. Path integrated concentration, LOS propagation fluctuations, and realistic cloud imaging are then simulated by multiplication of pseudorandom fluctuation outputs with smooth, ensemble averaged outputs from more traditional, simple obscuration models. Two platform-specific implementations of the generic texture routine were developed for IBM PC and Silicon Graphics, Inc. (SGI), display hardware. Examples of graphical output for both the two and three-dimensional algorithms are shown. Prepared in collaboration with New Mexico Univ., Physical Science Lab., Albuquerque, NM.