SYSTEME OPTRONIQUE PASSIF TRICHAMP

The invention concerns an IR passive imagery system (200) including: an IR matrix detector (10), - a two-field optical device, capable of forming an image on the detector and including image formation methods on an optical axis (20'), a removable afocal (30) of determined G magnification placed upstream of the image formation methods, an aperture diaphragm (40) placed between the detector and the image formation methods. It includes scanning methods (70') in the directional angle of the detective assembly and two-field optical device, since the aperture diaphragm (40) is removable and the optical device includes, in addition, a blockable backflushing mirror (81), arranged upstream of the image formation methods, and the image formation methods include methods for obtaining a third field, the backflushing mirror (81) and the methods for obtaining a third field being arranged on said optical axis and capable of forming an image on said detector (10) with the goal of obtaining a three-field imaging system.