USGS logoOct 25, 2013 • In the near future, calibration changes will be made that will affect the Thermal Infrared Sensor (TIRS) Band 10 and all of the Operational Land Imager (OLI) bands onboard Landsat 8.

The calibration for TIRS Band 10 will be lowered by a constant 0.32 W/(m2 sr µm) for every TIRS Band 10 pixel. This adjustment is being made due to significant discrepancies as compared to surface water temperature measurements. Studies are ongoing to better characterize the source of the calibration errors, and if possible, provide a more accurate scene-dependent correction. No adjustment will be made to TIRS Band 11, as indications are that its calibration is further off and more variable. Until indicated otherwise, users should work with TIRS Band 10 data as a single spectral band (like Landsat 7 Enhanced Thematic Mapper Plus (ETM+)) and should not attempt a split-window correction using both TIRS Bands 10 and 11.

Prior to this reprocessing effort, users can subtract 0.32 W/(m2 sr µm) from the TIRS Band 10 Top-Of-Atmosphere (TOA) radiance data to improve the accuracy of their current image products or to avoid downloading a new image product after reprocessing occurs. Once a more accurate scene-dependent correction is determined, a second purge and reprocessing will take place.

The OLI radiance-to-reflectance conversion coefficients will be adjusted for the cirrus band (Band 9) to account for on-orbit performance. The prelaunch derived coefficients were calculated using heliostat measurements, which were expected to be in error because little sunlight reaches the ground at these wavelengths. This adjustment changes the reflectance by about 7 percent in the cirrus band. Additionally, the precision of the other spectral bands’ radiance-to-reflectance conversion coefficients will be increased, changing the reflectance by up to 0.3 percent.

The relative gains of single detectors on the edges of each OLI Sensor Chip Assembly (SCA) will be updated to correct slight striping that is typically not visible. This update will affect all OLI spectral bands.

Source: USGS Landsat Project