NIST TXR Calibration of the GOES_R External Calibration Target (ECT) for the GOES_R Advanced Baseline Imager (ABI) Program
Raju V. Datla, Joseph P. Rice
The GOES_R/ ECT located at the ABI sensor test facility of ITT/Rochester was tested for its emissivity and radiance properties by deploying the NIST Thermal Infrared Transfer Radiometer (TXR) to the ABI cryogenic chamber at ITT/Rochester. The NIST/TXR was calibrated before and after deployment for its responsivity at its two channels at 5 µm and 10 µm respectively by using the NIST Water bath blackbody at ambient at various set points from 290 K to 343.3 K . In this report the emissivity values of ECT at the TXR channels deduced from the reflectance test are presented. Based on the emissivity values and the radiance measurements the blackbody temperatures were deduced for the set point temperatures of various PRTs mounted on the ECT. A calibration nist-equation was developed combining the results of both the TXR channels to predict calibrated temperature for any ECT set point temperature between 230 K to 340 K. The uncertainty of both the set point temperatures and the calibrated temperatures is estimated to be 100 mK (k=1). Also the radiance measured was compared with the expected radiance for the ECT set point effective temperatures based on the ITT thermal model.