Analysis and Modelling of the DIRT I and Graf II Battlefield Dust Obscuration Data

摘要

An analysis of photographic information is used to determine the source characteristics and the salient aspects of atmospheric diffusion for explosion-produced dust clouds. Specifically, the dependence of source strength (dust yield) upon the nature of the terrain and surface vegetative cover (sod) is identified. A partitioning of ejecta into essentially two distinct clouds, only one of which is buoyantly rising, is noted. Analytic solutions describing the diffusion of these two clouds taking into account the effects of vertical wind shear and gravitational settling are presented. Finally, experimental evidence indicative of large obscuration amplitude modulations is discussed and its association with effects due to large atmospheric eddies is suggested.