A new approach to wideband scene projection

Advances in the development of imaging sensors depend upon (among other things) the testing capabilities of research laboratories. Sensors and sensor suites need to be rigorously tested under laboratory and field conditions before being put to use. Real-time dynamic simulation of real targets is a key component of such testing, as actual full-scale tests with real targets are extremely expensive and time consuming and are not suitable for early stages of development. Dynamic projectors simulate tactical images and scenes. Several technologies exist for projecting IR and visible scenes to simulate tactical battlefield patterns - large format resistor arrays, liquid crystal light valves, Eidophor type projecting systems, and micromirror arrays, for example. These technologies are slow, or are restricted either in the modulator array size or in spectral bandwidth. In addition, many operate only in specific bandwidth regions. Physical Optics Corporation is developing an alternative to current scene projectors. This projector is designed to operate over the visible, near-IR, MWIR, and LWIR spectra simultaneously, from 300 nm to 20 μm. The resolution is 2 megapixels, and the designed frame rate is 120 Hz (40 Hz in color). To ensure high-resolution visible imagery and pixel-to-pixel apparent temperature difference of 100°C, the contrast between adjacent pixels is >100:1 in the visible to near-IR, MWIR, and LWIR. This scene projector is designed to produce a flickerless analog signal, suitable for staring and scanning arrays, and to be capable of operation in a hardware-in-the-loop test system. Tests performed on an initial prototype demonstrated contrast of 250:1 in the visible with non-optimized hardware.