Two Color Dynamic Scene Generator

OPTRA proposes the development of a two-color IR source simulator based on fused projected images of two digital micromirror devices (DMDs), one for each spectral band. The system employs a broadband IR (thermal) source whose energy is spectrally filtered via a dichroic beamsplitter and bandpass filters prior to being imaged onto each DMD. The “on” reflected image from each DMD is then recombined by the dichroic beamsplitter, and the fused beam is expanded by a telescope and transmitted towards the unit under test. The relative intensities of the two bands are controlled through the duty cycle of “on” versus “off” images reflected by each DMD. Because the IR source temperature is constant, response is considerably faster than resistive based simulators; similarly, thermal management issues are significantly less complex than with resistive arrays whose time constant depends on thermal management. Simplified thermal management may result in a lower power, more fieldable system. This approach provides a broadband simulation, unlike laser simulators, resulting in a more representative target with which to challenge an IR tracker. The overall approach offers the ability to realistically simulate the spectral, spatial, temporal, and radiant intensity properties of a number of targets for IR tracker test applications.