Development technology of large surface source infrared calibration blackbody on satellite

Abstract

This article elaborates on the working principle of the on-board blackbody calibration system, through the high-performance design and accurate index accuracy of the key indicators of high and low large-aperture surface blackbody (effective emission surface normal emissivity, temperature stability, temperature uniformity) Effective control, so as to obtain high and low temperature blackbody normal emissivity 0.98, temperature stability ≤ ± 0.15K/30min, temperature uniformity ±0.25K high-performance calibration indicators. By adding different thermal control measures to the high temperature black body and the low temperature black body, the temperature stability of the working temperature control interval required by each can be obtained. Among them, the temperature of the high-temperature black body is realized by applying a heat sheet with a reasonable cloth, while the temperature of the low-temperature black body is lower than the ambient temperature in the camera, and the temperature compensation is realized by installing a heat sink in the cold space, and then attaching the heating sheet to the heat pipe. For both high temperature blackbody and low temperature blackbody, precision platinum resistance thermometers are used to accurately monitor their temperature in real time. By reasonably arranging the position of the platinum resistance and the platinum resistance test line, the blackbody temperature measurement accuracy can be controlled within ±0.05°C. In the end, the high-stability large-aperture blackbody calibration system through the comprehensive work of various structural components, thermal control components and the main optical system to obtain the high-precision infrared temperature calibration requirements required by the load, which provides for subsequent model development. Successful engineering experience.