January 21, 2015 - Landsat 4-7 Surface Reflectance Data Fixes

By Landsat Missions

Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) version 2.2.1 was implemented on January 21, 2015 and includes the correction of two issues introduced by LEDAPS 2.2.0 on December 23, 2014:

1) HDF Scientific Data Sets (SDS) Attributes for QA Bands - The fill value for QA bands was eliminated in LEDAPS 2.2.0, but an erroneous fill value was still present in the SDS attributes as -3333, which is used as an internal flag to signify that the fill value does not actually exist. The "fill" attribute has been removed for QA bands in HDF SDS in the new release.

2) Reversed Class Values in QA Bands- Many of the class numbers in the .XML files and the class descriptions in the HDF SDS files were erroneously reversed. These have now been corrected such that “0” definitively indicates a condition has not been met, and “255” indicates that a condition has been met for fill, dark dense vegetation, cloud, cloud shadow, snow, and adjacent cloud.

Note that these changes do not impact the data values, only the attribute descriptions listed within the files and their metadata.