Abstract

The performance of an infrared system is expressed by a number of characteristics. In military equipment where the most important factor is long detection ranges, the ability of the equipment to detect the target in the presence of noise determines performance. The selection of a criterion would be simple if an infrared detection system had to detect only one target through an atmosphere of known, constant composition. However, because each system is required to perform against a variety of target spectra and through atmospheres of varying composition, a more general method of performance evaluation is required.

A new method, supplementing that currently used, is proposed. The responsivity curve of the equipment is obtained. The monochromatic (or nearly monochromatic) threshold of the system is determined at one or more points within the spectral passband where the responsivity is greater than 50%. The peak spectral threshold determined in this way expresses the least detectable flux to which the system can respond and is therefore believed to be a very important criterion. The relative response of the system to blackbody radiation between 273°K (0°C) and 6000°K is computed from the response curve, thereby more completely defining the system performance against various targets and backgrounds.

© 1960 Optical Society of America

Measurements with a Spectral Radiometer*

N. Ginsburg, W. R. Fredrickson, and R. Paulson
J. Opt. Soc. Am. 50(12) 1176-1186 (1960)

Distribution of Infrared Radiance over a Clear Sky

H. E. Bennett, Jean M. Bennett, and Max R. Nagel
J. Opt. Soc. Am. 50(2) 100-106 (1960)

Near Infrared Atmospheric Transmission to Solar Radiation

David M. Gates
J. Opt. Soc. Am. 50(12) 1299-1304 (1960)

Spectral Energy Thresholds for the Resolution of Acuity Targets*

John L. Brown, Lester Phares, and Dorothy E. Fletcher
J. Opt. Soc. Am. 50(10) 950-960 (1960)

Dependence on Atmospheric Pressure of the Response Characteristics of Thermopile Radiant Energy Detectors

A. R. Karoli, A. K. Ångström, and A. J. Drummond
J. Opt. Soc. Am. 50(8) 758-763 (1960)