<title>Human recognition of infrared images II</title>

Abstract

This paper presents the results of psychophysical experiments that addressed human recognition of infrared images. Three experiments are described in which human observers were asked to discriminate between different types of modern armored vehicles at various resolutions. In the original 1950s study, Johnson was concerned with the four criteria of detection, orientation, recognition, and identification, and a limited number of objects was used. This experiment used many more vehicles than Johnson used, but concerns only the tasks of identification friend or foe, and identification. The vehicles are ones that would be commonly encountered in a modern-day confrontation between NATO and Warsaw Pact Forces. Simulated infrared images of these vehicles were presented to trained observers and the resolution thresholds determined. Both signal detection theory and a simplistic percentage approach were used in the analysis of the results.