Advanced test station for imaging EO systems in the VIS to SWIR range

摘要

For surveillance and target acquisition systems the shorter wavelength regions, i.e. VIS/NIR and in particular SWIR (short wave infrared) have regained importance due to their unique information content and due to technological developments. There is a multitude of imaging systems in that range (400 nm to 1800 nm) extending from simple driver cameras for daylight operation (illumination levels 10 klux or more) to sophisticated night vision devices operating at illumination levels below 1 mix. Advanced systems using signal and image processing or even Artificial Intelligence (A)I will only work properly if some performance criteria are met. The requirements to test such systems are demanding. For these systems a suitable lab testing equipment is required to measure performance in a controlled manner. LEOSYS has designed and produced a flexible and yet compact test system, the AMT 10. This system is capable of covering over 8 decades of illumination resp. irradiation levels and a vast range of spatial frequencies of test patterns for the spectral range 400 nm to 1800 nm. The primary tests include the measurement of the Minimum Resolvable Contrast MRC, Modulation Transfer Function MTF, Signal-to-Noise S/N, and other figure of merits. The contrast can be adjusted continuously in the range from 100% to 0.1% with one single target. Using conversion filters, the setup can easily be adapted to different colour temperatures. The operation is PC controlled and occurs in a semi-automatic manner. The test station is calibrated not only in photometric and radiometric units, but also in the new SWIR radiance measure of Swux/sr.