Principal Investigator (PI): David Roy, Michigan State University
The Landsat satellites provide the longest temporal record of space-based earth observations. The 2012-2017 NASA MEaSUREs funded Global Web Enabled Landsat (GWELD) project has demonstrated the capability to generate global scale 30m Landsat composited mosaics with a monthly and annual reporting frequency for all of the earth’s terrestrial surface except Antarctica. The GWELD products and browses are generated on the NASA Earth Exchange (NEX) and have been reprocessed several times reflecting changes in the input Landsat format and algorithm improvements identified as a result of our intensive product quality assessment. The GWELD products provide consistent 30m data that are being used to derive land cover as well as geophysical and biophysical products. The most recent Version 3.0 GWELD products are available for the 2010 epoch (three years of monthly and annual products from 2009 to 2011). A total of 91.7 TB (>387,000 files) have been distributed from the USGS EROS equivalent to 128% of the product volume.
This project continuation takes advantage of USGS improvements in the processing of the Landsat Level 1 data (to Collection 1 and a conterminous United States (CONUS) gridded analysis-ready data (ARD) stream) that have only recently become available and that we helped define through our Landsat Science Team membership.
We will reprocess and continue the product generation of:
- Monthly and annual 30m global WELD products for six 3-year epochs centered on 1985, 1990, 1995, 2000, 2005, and 2010 (using the new Collection 1 Landsat data as inputs),
- Weekly, monthly, seasonal, and annual 30m CONUS WELD products from 1982 to 2012 (using the new Collection 1 CONUS ARD as inputs),
- Annual 30m percent land cover and 5-year land cover change products for the CONUS, 1985 to 2010 (using the data from (2) as inputs).
The products will be generated in reverse chronological order to take advantage of the growing U.S. Landsat archive as data continue to be repatriated from international receiving stations. The products will continue to be distributed in HDF, in GeoTIFF, and with native resolution browses via NASA's Global Imagery Browse Services (GIBS).