The SE-WORKBENCH workshop, also called CHORALE ("simulated Optronic Acoustic Radar battlefield"), is used by
the French MoD/DGA to perform multi-sensors simulations by creating virtual realistic multi spectral 3D scenes and
then generating the signal received by a sensor.
Taking advantage of developments made in the frame of Radar simulation, CHORALE is currently enhanced with new
functionalities in order to tackle the "active" problem, involving new generation of infrared sensors such as laser radars.
This article aims at presenting the challenges for simulating simultaneously passive IR imagery of a full terrain and
active imagery especially on targets. We insist on duality and differences concerning in particular
monochromatic/coherent waves versus incoherent waves, BRDF modeling taking into account surface roughness,
polarization effects, Doppler effects.
The SE-WORKBENCH implements the "Photon Map" method that enables to treat the "global illumination" paradigm,
consisting of multiple reflections ray tracing effects combined with Monte-Carlo ray scattering. This approach is
assessed in the frame of coherent illumination by laser. The constraint of the atmosphere propagation accurate
dependence on wavelength is also studied. Special requirements for advanced systems such as flash laser systems or
heterodyne infrared detectors are analyzed. Finally, modeling issues of the degradations introduced by atmospheric
turbulence are discussed.