Global Illumination Technique for Aircraft Infrared Signature Calculations

There is an increasing need of infrared signature knowledge of aerospace vehicles, both for defense and civilian applications, such as stealth technology, sensor design, and aerial obstacle detection for unmanned aerial vehicles. Models have been developed for this purpose by manufacturers or research laboratories, in order to predict infrared signatures of targets in the specific fields investigated. In some circumstances, it may be necessary to model complex radiative phenomena, such as diffuse reflections between different parts of the airframe, to improve the infrared target signature accuracy, or to help experimental image interpretation. An aircraft infrared signature modeling code, developed at ONERA, has been upgraded with a global illumination model, based on a Monte Carlo ray tracer, in order to evaluate the influence of these effects. First, this paper presents the main characteristics of the code and the principles of the rendering method. Next, comparisons are accomplished with another simulation tool and experimental data as well. The benefit of this approach in aircraft infrared signature computation is then discussed.