Design and performance test of self-calibration multichannel infrared radiometer

In order to meet the needs of automated observation calibration for remote sensor thermal infrared band, a self-calibration multichannel infrared radiometer with automated observation capability was developed. The equipment has the following features: 1) the design of motor-driven gold-plated reflector was used to achieve the measurement of downward atmospheric radiation and surface radiance at an elevation angle of 0°~90°, which provided the technical means to eliminate the influence of downward atmospheric radiation on inversion surface temperature; 2) the filter wheel spectrometry was used to realize the automatic setting of 6 spectral channels, and combined with the multichannel temperature and emissivity separation algorithm, the separation of site temperature and emissivity could be achieved, which provided 2 key factors for the absolute radiometric calibration of satellite remote sensor thermal infrared band; 3) a black body with two built-in temperature control accuracy better than 0.04 K and 0.05 K, emissivity higher than 0.994, stability better than 0.001 4 was used to achieve the real-time radiometric calibration of the internal detector, which effectively eliminated the influence of internal background radiation on radiation measurement. The calibration uncertainty is less than 0.167%, and the equivalent temperature measurement uncertainty is 0.2 K (@303 K, 11 μm), which lays the foundation for the application of site automated calibration for remote sensor thermal infrared band.