Radiometric dynamic scene processing for uncooled IRFPAs

Abstract

The widespread use of cameras based on uncooled infrared focal plane arrays (IRFPAs) is largely because of rapid commercialization, impressive miniaturization, and low per-unit cost. As performance improves, long-wave IR cameras using uncooled IRFPAs have replaced more expensive cooled units in many applications. The uncooled units generally have a much higher noise floor. However, if the signal is robust, the uncooled units can make the measurements at lower cost. New cameras with smaller pixels continue to reduce the pixel response time, enabling higher frame rates and more applications. Uncooled IRFPAs are thermal detectors, not charge-based devices, and the implicit pixel response time can greatly affect radiometric accuracy. In addition to the pixel response time, the fidelity of radiometric measurements is affected by target size, pixel fill factor, spectral response, stray light, self-heating, and other variables. If radiometric accuracy is required, it is necessary to quantify the effects of these variables. Calibration methods and measurement compensation techniques are described with emphasis on dynamic scene processing applications.