NCJ Number
84989
Journal
Police Research Bulletin Issue: 38 Dated: (Spring 1982) Pages: 45-49
Date Published
1982
Length
5 pages
Annotation
Thermal imaging equipment, which produces images that show the relative temperatures of objects being scanned, is useful for surveillance and searching for live people.
Abstract
A thermal imager gives a normal picture of the scene (often on a TV) with the shapes of things normally the same but with a brightness controlled by the temperatures of the objects in the picture. The thermal imager will work in total darkness. Thermal imagers are potentially better than normal night vision equipment, because they will ignore any background clutter and respond to the heat given off by any persons in the scene. In sparse woodland, any part of a person revealed from behind trees and shrubbery shows up well on the imager, whereas they tend to be camouflaged with the use of the intensifier. Further, when light levels are very low or the subject is in shadow, the thermal imager gives a better chance of detection. The imager also permits detection of cars or boats whose engines are putting out heat while operating or after having only recently been running. Thermal imaging is currently more expensive and cumbersome than night vision intensification equipment. The hand-held MEL equipment, which is probably the most useful for general police work, costs about 8,000 pounds. Thermal imagers are unsuitable for searching for dead bodies or for seeing through glass. Technical specifications for two types of imagers are provided.