SNPP and NOAA-20 VIIRS calibration anomaly
Posted: Fri Jan 17, 2020 10:02 am
Dear Colleagues,
This note is to let you know that VIIRS data from both SNPP and NOAA-20 are currently affected by a calibration anomaly. Yesterday we received this message from the NOAA VIIRS calibration team:
“There has been an anomaly in the VIIRS SDR reflective bands calibration for both NOAA-20 and S-NPP because of incorrect solar vector calculations since about 2020-01-16 0:00 UTC. For S-NPP VIIRS SDR, both radiance and reflectance products are affected because the RSB calibration coefficients have not been updated since 2020-01-16 0:00 UTC. For NOAA-20 VIIRS SDR, radiance products should not be affected by this anomaly, but the reflectance products are affected because of the solar zenith angle errors. The root cause of the problem is still not known and is under investigation. More information will be provided when it becomes available.”
VIIRS data are currently not usable as a result. The anomaly is being observed in global VIIRS data from both NOAA and NASA, as well as VIIRS data obtained from direct broadcast and processed by CSPP SDR.
At this time we do not know when the problem will be resolved.
This note is to let you know that VIIRS data from both SNPP and NOAA-20 are currently affected by a calibration anomaly. Yesterday we received this message from the NOAA VIIRS calibration team:
“There has been an anomaly in the VIIRS SDR reflective bands calibration for both NOAA-20 and S-NPP because of incorrect solar vector calculations since about 2020-01-16 0:00 UTC. For S-NPP VIIRS SDR, both radiance and reflectance products are affected because the RSB calibration coefficients have not been updated since 2020-01-16 0:00 UTC. For NOAA-20 VIIRS SDR, radiance products should not be affected by this anomaly, but the reflectance products are affected because of the solar zenith angle errors. The root cause of the problem is still not known and is under investigation. More information will be provided when it becomes available.”
VIIRS data are currently not usable as a result. The anomaly is being observed in global VIIRS data from both NOAA and NASA, as well as VIIRS data obtained from direct broadcast and processed by CSPP SDR.
At this time we do not know when the problem will be resolved.