The U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center in Sioux Falls, SD developed a cloud validation dataset from 48 unique Landsat 8 Collection 1 images. These images were selected at random from the Landsat 8 archive from various locations around the world. While these validation images were subjectively designed by a single analyst, they provide useful information for quantifying the accuracy of clouds flagged by various cloud masking algorithms. Each mask is provided in GeoTIFF format, and includes all bands from the original Landsat 8 Level-1 Collection 1 data product (COG GeoTIFF), and its associated Level-1 metadata (MTL.txt file). The interpretation for the pixel values in each cloud mask is as follows: Value Interpretation 0 Fill 128 Clear 192 Thin Cloud 255 Cloud The methodology used to create these masks is the same as in previous USGS Landsat cloud truth masks (http://doi.org/10.5066/F7251GDH). Pixels are marked as Cloud if the pixel contains opaque and clearly identifiable clouds. Pixels are marked as Thin Cloud if they contain clouds that are transparent or if their classification as cloud is uncertain. Pixels that contain clouds with less than 50% opacity, or which do not contain clouds at all, are marked as Clear. In some masks the borders around clouds have been dilated to encompass the edges around irregular clouds.
