<title>Static image system MRTD modeling</title>

Abstract

The Minimum Resolvable Temperature Difference (MRTD) is the standard for measuring the performance of infrared imaging systems. Refined and validated modeling programs can accurately predict MRTD for scanning and staring Forward Looking Infrared (FLIR) imaging systems operating at video frame rates. However, there is a need to predict the MRTD performance of infrared systems that display imagery as static frames. Infrared imaging systems used for reconnaissance operate at low frame rates of about 1 to 5 Hz (framing cameras), or continuously gather imagery line by line (line scanners). Typically, each image is of a different scene and is displayed as a static image or in a waterfall display. Under normal lighting conditions, the human eye has a temporal bandwidth of approximately 10 Hz. Therefore, the perceived sensitivity, measured at MRTD, of these low frame rate systems is lower than a comparable video frame rate imaging system. The low frame rate systems do not benefit from the temporal filtering effect of the human eye as video frame rate systems do, and should exhibit a higher MRTD. This paper presents data comparing predicted MRTD performance calculated by the FLIR92 program with measured performance.