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NASA Web-Enabled Landsat Data Alaska 30m Composites over Monthly Periods V001

Published by LP DAAC;SD-STATE/GISCCE | National Aeronautics and Space Administration | Metadata Last Checked: February 21, 2026 | Last Modified: 2026-02-17
WELDAKMO.015 was decommissioned on December 2, 2019. Users are encouraged to use the improved monthly Global Web-Enabled Landsat Data (GWELD) [Version 3](https://doi.org/10.5067/MEaSUREs/GWELD/GWELDMO.003), [3.1](https://doi.org/10.5067/MEaSUREs/GWELD/GWELDMO.031), and [3.2](https://doi.org/10.5067/MEaSUREs/GWELD/GWELDMO.032) datasets.NASA’s Web-Enabled Landsat Data (WELD) are generated from composited 30 meter (m) Landsat Enhanced Thematic Mapper Plus (ETM+) mosaics of the United States and Alaska from 2002 to 2012. These mosaics provide consistent data for deriving land cover, geophysical, and biophysical products for regional assessments of surface dynamics for effective study of Earth system function. The Alaska Monthly products are defined with respect to each calendar year by the days in each month. This product includes Top of Atmosphere (TOA) Reflectance and Brightness Temperature, along with the Normalized Difference Vegetation Index (NDVI) generated from Band 3 and Band 4 TOA Reflectance. These products are distributed in Hierarchical Data Format 4 (HDF4).The WELD project is funded by the National Aeronautics and Space Administration (NASA) and is a collaboration between the United States Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center and the South Dakota State University (SDSU) Geospatial Sciences Center of Excellence (GSCE). Known Issues* WELD Version 1.5 known issues can be found in the WELD Version 1.5 User Guide.Improvements/Changes from Previous Version* Version 1.5 is the original version.

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