The reflective solar bands (RSB) of Terra MODIS have experienced relatively large degradation in recent years. The current calibration algorithm used in deriving the Collection 5 LUTS does not completely capture and correct for this degradation, which is both wavelength and angle-of-incidence dependent. Science data products that utilize the shorter wavelength bands, especially Bands 8 (412 nm), 9 (443 nm) 3 (469 nm), 1 (646 nm), and 2 (856 nm) can expect to see an observable impact on data quality. An example of the observed degradation on Terra band 8 and 1 are provided in the attached file.
The proposed calibration algorithm improvements in development for Collection 6 LUTs are expected to significantly reduce these impacts. These LUTs will be put into production after a thorough review and testing process is completed.
Further details are available in the MCST presentation at the Calibration breakout session of the May 2011 MODIS Science Team Meeting (http://modis.gsfc.nasa.gov/sci_team/meetings/201105/)