In the atmosphere, pointlike sources are surrounded by aureoles because of molecular and aerosol scattering. In various meteorological conditions, this variance field can be a nonnegligible part of the signal detected by a large-field-of-view sensor. A model based on a Monte Carlo technique has been developed to simulate the propagation of radiation coming from a UV point source. The model was validated with an experimental comparison by a photon-counting technique, and good agreement between experimental and theoretical results was found.