Long-term Calibration Performance of MODIS Thermal Emissive Bands

Terra and Aqua MODIS, key instruments for NASA’s Earth Observing System missions, have operated continuously for more than 12 and 10 years respectively. The science products generated from MODIS data are used worldwide in studies of the Earth’s ocean, land, and atmosphere systems. As the sensors age well past their prime design life of 6 years, understanding the instrument on-orbit performance is imperative to continued production of high quality calibrated data. The 16 thermal emissive bands (TEB), covering wavelengths from 3.5 to 14.4 μm with a nadir spatial resolution of 1-km, use on-board blackbody (BB) and space view observations on a scan-by-scan basis to track the response changes of the TEB detectors. A quadratic algorithm calibration methodology is applied for TEB and is presented here in addition to the long-term performance of both MODIS sensors, in terms of on-orbit temporal stability of detector gain, detector noise, and BB temperature control. Also discussed here are issues and challenges for continued successful MODIS operation