Infrared background and target measurement.

Abstract

The present work describes Measurements of IR background radiance . To provide background radiance values for the development of the AN / SAR - 8 (IRSTD) system, the radiance of clouds and buildings was measured using the A6A Thermovision 780 . The measurement values given in Isotherm Units ( photon flux equivalent ) were translated into radiance values (W/cm²sr). The emissivity of the different objects was also computed for the 8-14 µm window assuming that their emissivity in the 3-5.6 µm band is close to that of a blackbody. The average radiance of clouds was found to be 3.302 X 10⁻⁴ W/cm²sr in the 3-5.6 µm window and 3.544 X 10⁻³ W/cm²sr in the 8-14 µm window. The corresponding values for buildings were 3.587 X 10⁻⁴ W/cm²sr and 4.552 X 10⁻³ W/cm²sr respectively.