Vacuum large-aperture black body model in the temperature range of 223.15–423.15 K for radiometric calibration of optoelectronic equipment for earth observations

Abstract

The article presents the structure of systems for radiometric calibration for the Earth remote sensing optoelectronic equipment in the infrared spectrum range. Analysis of existing facilities for radiometric calibration of the Earth remote sensing optoelectronic equipment in conditions of vacuum and low-background radiation was carried out. These facilities are based on using the black body models as radiation sources, including reference sources based on the phase transition of pure metals, for example gallium or indium. A large-aperture black body model LABB-380 with an aperture diameter of 380 mm in the temperature range of 223.15–423.15 K has been developed. LABB-380 is part of a high-vacuum low-background test rig currently being developed at the Scientific Research Institute of Optoelectronic Instrumentation for the radiometric calibration of the Earth remote sensing optoelectronic equipment. The results of calculating the normal effective emissivity of the LABB-380 surface in the above temperature range and the spectral range of 3–20 μm are presented. The metrological characteristics of LABB-380 obtained during the transmission of a temperature unit from the State Working Standard of the zero category of a temperature unit in the range from 0 to 3000 °C (Registration No. 3.1.ZZA.0020.2015) using a comparator based on the HETRONIXS precision pyrometer have been studied. According to the calibration results in the temperature range of 300.15–390.15 K, the instability of the LABB-380 radiation was 0.005 K, the extended temperature uncertainty was 0.66 K at the temperature of 300.15 K and 0.88 K at 390.15 K.