MODIS Daytime SST reprocessed

by **OB.DAAC - SeanBailey** » Wed May 24, 2017 2:59 pm America/New_York

As of 18 May 2017, the daytime SST products for MODIS from both Terra and Aqua have been reprocessed to implement a minor correction to the quality flagging.

The MODIS Aqua and Terra R2014.0 daytime SST was found to have a higher false positive cloud misclassification rate than expected. The problem was traced to an issue with a few of the visible band tests of the cloud classification algorithm. Thresholds based on reflectance were being compared against units of radiance, and on occasion this resulted in large areas of clear pixels being misclassified as cloud. Misclassification was dependent on the single path a pixel took through a series of tests in the Classification Tree. In addition to correcting the issue in the SST cloud classifier, L3 map products for the R2014.0.1 use improved mapping software, L3mapgen, based on weighted spatial averaging rather than the previous nearest neighbor methodology of the SMI maps. Users may find minor differences in the mapped values due to changes in the mapping method, in addition to any change due to the increased number of best or good quality retrievals in some L3 bins in the ISEAG grid.