An assessment of the impact of fused monochrome and fused color night vision displays on reaction time and accuracy in target detection

Abstract

Night Vision Devices (NVDs) employed by the military fall into two categories: Image Intensifiers (I2) also known as Night Vision Goggles (NVGs) and Infrared (IR). Each sensor provides unique visual information not available to the unaided human visual system. However, these devices have limitations and they have been listed as a causal factor in many crashes of military aircraft at night. Researchers hypothesize that digitally fusing the output from these sensors into one image and then artificially coloring the image will improve an NVD user's visual performance. The purpose of this thesis was to determine if fusion and coloring of static, natural scene NVG and IR imagery will improve reaction time and accuracy in target detection. Pairs of static images from three different scenes were obtained simultaneously from NVG and IR sensors. The six original images were fused pixel by pixel and then colored using a computer algorithm. A natural target was moved to two other coherent positions in the scene or completely removed, resulting in twenty-four images for each of the three natural scenes. Six subjects viewed the images randomly on a high- resolution monitor, rapidly indicating on a keypad if the target was present (1) or absent (2). Reaction time and accuracy were recorded. An ANOVA on the output and a subsequent review of the images revealed that fusion significantly impacted local (target) contrast and that, coupled with scene content, decreased performance on the task.