The Web-enabled Landsat Data (WELD) project is collaboration between the United States Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center and academic partner South Dakota State University Geographic Information Science Center of Excellence. It is funded by NASA's Making Earth System Data Records for Use in Research Environments, with significant USGS cost sharing.
WELD generates 30-meter composites of Landsat 7 Enhanced Thematic Mapper Plus (ETM+) terrain corrected (Level 1T) mosaics at weekly, monthly, seasonal and annual periods for the conterminous United States (CONUS) and Alaska. These mosaics provide consistent data that can be used to derive land cover as well as geo-physical and biophysical products for regional assessment of surface dynamics and to study Earth system functioning.
The WELD documentation site describes the WELD products, known issues, and future plans.
The latest version of WELD products is now available as custom GeoTiff subsets via a new interactive web ordering system and as tiled HDF products via FTP.