Performance of MODIS thermal emissive bands on-orbit calibration algorithm

MODIS has 16 thermal emissive bands (TEB) covering wavelengths from 3.75 to 14.24 ¿m. They are calibrated on a scan-by-scan basis using a quadratic calibration algorithm and data collected from detector responses to the instrument on-board blackbody (BB) and space view (SV). The MODIS on-board BB was designed to be capable of operating at temperatures varying from instrument ambient (about 270 K) to 315 K. This function has allowed the TEB nonlinear calibration coefficients to be characterized on-orbit and updated as needed. Following a brief description of MODIS TEB calibration methodologies and BB on-orbit operations, this paper provides an assessment of algorithm performance. Variations of detector short-term and long-term responses and their calibration impact are examined and quantified. Individual contributions from the BB, instrument scan cavity, and scan mirror thermal emissions are analyzed. A comparison is also made of Terra and Aqua TEB on-orbit performance.