Development of a polarimetric thermal imager calibration method

Abstract

Measurement of thermal imager characteristics is important for the reliable and efficient operation of the device in various fields, including science, medicine, and industry. Incorrect measurements can lead to errors, which can be critical, especially for military-grade thermal imagers. This article is dedicated to developing a method for monitoring the output parameters of polarimetric thermal imagers based on calibration. During calibration, the following operations are proposed: visual inspection, functionality check, measurement of polarimetric thermal imager parameters, and evaluation of measurement uncertainties. In this article, the controlled parameters of the polarimetric thermal imager are the measured for device temperature and NETD, Noise Equivalent Temperature Difference. For these parameters, a measurement model, a measurement function, and an uncertainty budget have been developed. The uncertainty budget includes only the main and most influential uncertainty components. This methodology can only be used for one type of polarimetric thermal imager, where the determination of the radiation polarization state is achieved by rotating a phase plate.