FY-3B/VIRR 真空红外定标辐射响应度一致性校正

In vacuum infrared calibration, factors, such as test contamination and non-uniformity of instrument temperature, cause response changes for scanning radiometer system, resulting in inaccurate calibration coefficients and platinum resistance conversion coefficients for each channel. The non-uniformity of the responsivity is corrected using the stability of the blackbody as a reference source in the constant temperature mode and the responsivity invariance in the single calibration state for the infrared detection system. The transfer algorithm of the consistent response from the internal to external blackbody measurement for the infrared channels is established by the data of variable temperature test for the surface blackbody and on-board blackbody in the infrared calibration. For the prelaunch calibration data of FY-3B visible infrared radiometer (VIRR), the non-uniformity of system responsivity is corrected during the calibration. At the temperature change stage, the uniformity of the correction signal for the surface blackbody between the heating-up and cooling-down stages is better than 0.7 digital number. In the radiance transfer stage, the uniformity of the correction signal for the on-board blackbody is better than 0.3 digital number in the reference condition. The difference between the correction method and other traditional methods in calculating the equivalent blackbody temperature of the on-board blackbody is analyzed. This algorithm ensures the transfer accuracy from the space-based radiance standard to the infrared detection system and on-board blackbody, and the technical support is provided to effectively improve the accuracy of vacuum infrared calibration.