Search for noisy coloured tracks camouflaged by noisy coloured backgrounds

Abstract

A total of 67 naval ratings searched for target tracks. Four groups searched for complete target tracks only, while four other groups searched for both complete and faded target tracks. The target tracks were lines of hexagons with a constant average slope, and of a single colour, cither red, yellow, green or blue. They were camouflaged by a full background matrix, comprising about 44% of both yellow and green hexagons, and about 6% of both red and blue hexagons, arranged randomly.

The heavily camouflaged yellow and green target tracks were detected reliably less well than the lightly camouflaged red and blue target tracks. The differences were particularly marked with the faded target tracks. The interaction between camouflage and fading was highly reliable. With the heavy camouflage, searching for target tracks with a single fade produced a number of false detections. Whereas with light camouflage, searching for target tracks with up to three fades produced no false detection. Thus heavy camouflage is particularly detrimental when searching for faded target tracks.