In this paper we present MATISSE 1.1 a new background scene generator, whose goal is to compute spectral or integrated radiance images of natural background, as well as the transmission of a hot gas signature.
The spectral bandwidth for this version of the code is from 750 to 3300 cm-1 (3 to 13 μm) with a 5 cm-1 resolution. Gaseous absorption is computed by a Correlated K model. The spatial variability of atmospheric quantities (temperatures and mixing ratios, among others) is taken into account, using variable profiles along the line of sight.
Natural backgrounds include the atmospheric background, low altitude clouds and the Earth ground. The radiation models used are designed for observation at low spatial resolution of clouds and soils, so a texture model was developed to increase the high spatial resolution rendering in the metric range.
Intermediate outputs of the code deliver radiance and transmission restricted to a single line of sight, in which case atmospheric refraction effects are taken into account. Along this line of sight the transmission can also be computed using a line-by-line model, which is useful to propagate the radiation emitted by a hot gas source (fires, aircraft or missile plume).
MATISSE 1.1 was released in June 2002, so this paper is devoted to a presentation of the first results obtained with the code and some validation tests.