Discrete resistive elements versus a black body source for thermal imager testing

Abstract

A comparison of four bar target image data in the long wave infrared range using a conventional blackbody source and a discrete resistive element source is made to assess the ability of an infrared scene projector to test thermal imagers such as forward looking infrared (FLIR) systems. The test equipment used to accomplish the comparison is comprised of four basic elements. These include a QWIP radiometer, a blackbody source with 0.6 cycles/mrad 7:1 aspect ratio four bar target, an infrared scene projector, and video frame capture electronics and analysis software. The video from the radiometer of each source is used as a means of comparing and contrasting the relative performance of an etched target in front of a conventional extended blackbody source and a resistive array source. The infrared image from each source is captured by the radiometer, digitized, and subsequently analyzed. Characteristics from the digitized imagery such as uniformity and intensity modulation of the 4 bar pattern and background are used as objective measures to assess the relative performance between the two approaches.