a. KWIK@ an acronym for crosswind integrated concentration@ is a smoke munitions expenditures model developed by Umstead@ Pena@ and Hansen [1] for the US Army Research Laboratory (ARL). This publication includes the most recent improvements to the model@ which is designed for use with eight inventory munitions (listed in Table 2 of Chapter 2). ARL's Combined Obscuration Model for Battlefield-Induced Contaminants (COMBIC) has been used to verify and modify munition-sustaining rates of fire.b. The KWIK model contains seven subroutines@ which are listed as part of the source code in Annex B. KWIK munition calculations predict the required number of white phosphorus (WP) or hexachloroethane (HC) howitzer and mortar munitions necessary to reduce the probability of target detection to a given level. The threshold transmittance levels used by the module are 0.10 for visible and near-infrared (IR) and 0.05 for mid- and far-IR wavelengths. Mathematical solutions for atmospheric transmission through smoke@ microscale diffusion@ and munition expenditure calculations are given in the description of the model development.?