The light through the Terra band 31 (11 µm) filter leaks into bands 32-36 (12-14 µm).
Impact to L1B Data Set
The light leak from Band 31 (sensitive to signals from the surface) produces surface feature "ghosts" in the images for Bands 32-36. A correction is applied to each detector response in bands 32-36. The correction, which is frame shift dependent, subtracts a small portion of the detector response of Band 31's nearest detector from the band 32-36 response. The coefficients for receiving Bands 32 - 36 are approximately 1%, 1.5%, 2.5%, 5% and 2.5%, respectively.
Estimated Impact to L2 Science Products
Following implementation of the mitigation approach in L1B, the impact of this optical crosstalk on L2 products is less than 0.1% of the EV radiance.
Cause of Effect
This optical cross-talk is caused by scattering off the bottom edge of the Band 31 spectral filter. The scattered energy is reflected between the filters and the detectors for Bands 32-36.
Mitigation Approach/Added Testing to Characterize Effect
Corrections have been applied based on pre-launch testing and on-orbit studies (moon observation and SRCA data), including studies of these ghosts. The correction coefficients in the LUT for receiving Bands 32 - 36 are approximately 1%, 1.5%, 2.5%, 5% and 2.5%, respectively.
Estimated Schedule to Complete
The correction is used in the collection 5 product after August 10, 2000. For collection 6, the correction will be used for all time periods in the mission.
History of Characteristic
|Time Span||Version Number at|
start of epoch
|1||Entire mission||6||Light leak||Correction coefficients applied||Memos M215, 222, 842, 919, 960, 976, 1049, 1052|