Vacuum large-aperture blackbody model in the temperature range 223.15–423.15 K for radiometric calibration of optoelectronic equipment for Earth observation

Abstract

The structure of the systems for the radiometric calibration of the remote sensing optoelectronic equipment in the infrared spectral range is presented. The analysis of existing facilities for the radiometric calibration of the remote sensing optoelectronic equipment in conditions of vacuum and low-background radiation was carried out. These facilities are based on using of the blackbody models as radiation sources, including reference sources based on the phase transition of pure metals, for example gallium or indium. The wide-aperture blackbody model LABB-380 with an aperture diameter of 380 mm in the temperature range from 223.15 K up to 423.15 K has been developed for a high-vacuum low-background stand, which is currently being developed at the Sciences Research Institute of Optoelectronic Instrumentation for the radiometric calibration of the remote sensing optoelectronic equipment. The results of calculating the normal effective emissivity of the surface of the LABB-380 in the temperature range from 223.15 K to 423.15 K in the spectral range from 3 to 20 μm are presented. The metrological characteristics of LABB-380 obtained during the transmission of a temperature unit from the zero discharge State Standard using a comparator based on the precision pyrometer HETRONIXS are investigated and presented. The instability of the LABB-380 radiation was 0.005 K according to the calibration results in the temperature range from 300.15 K to 390.15 K, and the extended temperature uncertainty was 0.66 K at the temperature of 300.15 K and 0.88 K at a temperature of 390.15 K.