Design and performance test of self-calibration multi-channel infrared radiometer

In order to meet the needs of automated observational absolute radiometric calibration of satellite remote sensing thermal infrared band, a self-calibration multi-channel infrared radiometer with automatic observation capability was developed. The equipment needs to have the following features: 1) The design of the motor-driven gold-plated reflector is used to achieve the measurement of atmospheric downward radiation and surface radiance at an elevation angle of 0°～ 90°, which is provided to eliminate the influence of atmospheric downward radiation on inversion of surface temperature Technological means. 2) The method of filter wheel spectrometry is used to realize the automatic setting of 6 spectral channels. Combined with the multi-channel temperature and emissivity separation algorithm, the separation of site temperature and emissivity can be achieved, which provides absolute radiation calibration for the thermal infrared band of satellite remote sensors. There are two key factors. 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 both better than 0.001 4 is used to achieve real-time radiation calibration of the internal detector, effectively eliminating internal background radiation For the effect of radiation measurement, the calibration uncertainty is less than 0.167%. The equivalent temperature measurement uncertainty is 0.2 K (@303 K, 11 μm), which lays the foundation for the application of automatic calibration of the infrared thermal field in the remote sensor.