Analytical Dependence of the Probability of Masking Objects on the Density and Dispersion of the Aerosol

   With the existing method for evaluating the effectiveness of masking objects with aerosols, two parameters are used: the length and width of an invisible smoke screen with a probability of at least 50 %. Both parameters were obtained during the practical tests of aerosol masking means. However, they are insufficient for assessing the masking ability of an aerosol cloud as a spatial formation.   The purpose of this work is to reveal the analytical dependence of the probability of objects masking on the density and dispersion of the aerosol.   Мaterials and methods. An extended approach was used to estimate the probability of masking at any theoretical value of the flux density (integral concentration, g/m2) of aerosol along the line of sight, taking into account its dispersion, by calculating the formation of a probability field from 5 to 95 % over the entire spatial structure of the aerosol cloud. The method used is the simulation on a PC of the dependence of the share of space occlusion for the observer (the eyepiece of an optical device) by aerosol particles of a given dispersion and flux density, which we took as the probability of masking.   Discussion. It is shown in the article, that the resulting analytical expression as a result of processing the accumulated simulation results on a PC fully corresponds to the Bouguer-Lambert-Beer law, which is a generalization of many years of practical field and laboratory experiments with aerosols in the air and dispersed particles in solutions. The obtained probability values allow us to obtain a generalized efficiency criterion in the form of a new concept - the reduced masking zone. This term is mathematically analogous to the reduced impact zone, which is used to assess damage caused by munitions.   Conclusion. For a full assessment of the effectiveness of aerosol countermeasures, the reduced masking zone must be calculated for all possible lines of sight (observation of an object): horizontally, vertically, and along inclined paths. This condition reflects the method of using modern weapons such as Javelin anti-tank systems, which are aimed at the target mainly horizontally, and the final trajectory before the impact is a «hill». The theoretical difference between the values of vertical and horizontal masking screens, obtained by the authors using a new method for calculating the parameters of an aerosol cloud, is presented in the illustrations to the article.