Proceedings Article | 10 May 2011
Proc. SPIE. 8014, Infrared Imaging Systems: Design, Analysis, Modeling, and Testing XXII
KEYWORDS: Target detection, Thermography, Eye, Data modeling, Visualization, Camouflage, Motion models, Motion measurement, Performance modeling, Electro optical modeling
The construction and validation of soldier combat models requires data on the conspicuity of camouflaged targets in the
field, and human targets in particular. So far, this data is lacking. Also, it si currently unknown to what degree luminance
contrast and motion contribute to target conspicuity. These data are needed to enable the validation and further
development of human visual search performance modules in soldier combat models like SCOPE or IWARS. In this
study we measured the conspicuity of a person wearing a Dutch army camouflage uniform, while he was either standing
still, walking or running along a forest in the background, both for viewing with the naked eye (NE) and for viewing
dynamic thermal scene recordings (IR). We varied the viewing distance (80m and 230 m), the camouflage pattern
(woodland and desert), the type of background (pine-tree and deciduous forest), and season (summer and winter), The IR
(thermal) conspicuity of the person was much larger than his NE (visual) conspicuity. In both cases the effects of
movement were large and saturated as a function of retinal target speed. For NE, we find large effects of shading that can
not explained by local luminance contrast variations. Also for NE, conspicuity was reduced in winter, probably as a
result of an increase in scene clutter. The results suggest that conspicuity is not only a function of retinal target motion
and global luminance contrast, but also depends on the amount of clutter in the scene.
