Evaluation of a color fused dual-band NVG

We designed and evaluated a dual-band night vision goggles sensor system. The sensor system consists of two optically aligned NVGs fitted with filters splitting the sensitive range into a visual and a near-infrared band. The color-the-night technique (Hogervorst & Toet, FUSION2008) was used to fuse the images of the two sensors, using a color scheme optimized for the detection of camouflaged targets. The added value of this system was established in an experiment in which observers detected targets (green and blue tubes). Performance was measured for daytime imagery and nighttime imagery: each of the two individual bands, standard NVG, and the color fused sensor system. We found that some of the targets were detected in the individual bands, but most targets were detected in the dual-band system. The fact that performance in the dual-band condition is comparable to the sum of the two individual bands indicates that the fusion method is (close to) optimal. An experiment in which subjective reports were gathered shows that the colored dual-band images are easier to grasp and give a better sense of depth. Our evaluation shows the added value of dual-band over single band NVG for the detection of targets, situational awareness, and perceived depth.