Two-band DMD-based infrared scene simulator

OPTRA is developing a two-band midwave infrared scene simulator based on digital micromirror devices (DMD). The simulator is intended for testing a number of different infrared tracking technologies. Our approach allows for the relative intensities of the two spectral bands to be varied for realistic simulations of an approaching target. The system employs a broadband IR (thermal) source whose energy is spectrally filtered via a series of bandpass filters acting as dichroic beamsplitters prior to being imaged onto two DMDs - one for each spectral band. The "on" reflected images from the two DMDs are then fused, expanded by a telescope, and transmitted towards the unit under test. The relative intensities of each spatial element of the two bands are controlled through the duty cycle of "on" versus "off" of the related micromirror. In this paper we present a breadboard design, build, and test which establishes the feasibility of our approach. A description of the opto-mechanical system is given along with radiometric performance projections. Results from breadboard testing, including maximum radiant intensity and radiant intensity resolution, and a series of simulated images are shown.