Case #:PM_MOD21_21200  Opening date: 07/19/21  Last update: 07/19/21|
Users of the different MODIS and VIIRS LST products, generated by MODAPS and NASA LandSIPS, may notice more occurrences of extreme high temperature outliers in the MxD21 (C6/C61) and the VNP21 (C1 S-NPP VIIRS) products, compared to the heritage MxD11 LST products. One reason for this is a tighter filtering for clouds employed in the MxD11 code, for daily and n-day products, that is based on a temporal analysis of LST over cloudy areas. The MxD11 code could also be using some additional dust removal filter that we are not fully certain of at this time.
In order to alleviate this issue in the MxD21 and VNP21 products from C6/C61 (MODIS) and C1 (S-NPP VIIRS), the MxD21 science team recommends using a combination of the existing QC bits, emissivity values and estimated product errors, to confidently remove bad pixels from analysis. For more details regarding this, the users can refer to this documentation.
Occurrence: MxD11, MxD21 (C6/C61) and the VNP21 (C1 S-NPP VIIRS) LST products as described above.