Alaska Landsat Composites with Seasonal NDVI and Temperature

NASA's Web-Enabled Landsat Data (WELD) provides 30-meter resolution seasonal mosaics of Alaska from 2002 to 2012. The dataset includes Top of Atmosphere Reflectance, Brightness Temperature, and derived Normalized Difference Vegetation Index (NDVI) values. This project was a collaboration between NASA, the USGS EROS Center, and South Dakota State University.

Use Cases

• Analyzing seasonal vegetation health trends using the NDVI values derived from Band 3 and Band 4 reflectance.
• Monitoring land cover change over a decade using the consistent 30-meter resolution TOA Reflectance composites.
• Studying surface temperature patterns via the provided Brightness Temperature data.
• Conducting regional assessments of surface dynamics for climate or ecological studies.

Strengths

• Provides a consistent 11-year time series from 2002 to 2012 for longitudinal analysis.
• Offers high-resolution 30-meter spatial detail from Landsat ETM+ sensors.
• Includes scientifically derived indices like NDVI for direct vegetation analysis.

Limitations

• The dataset is decommissioned, with users directed to newer GWELD versions, indicating it is not the current standard.
• Sources conflict on the last updated date: one platform lists 2026-03 12 (likely a metadata refresh), while the authoritative source indicates the data ended in 2012-11-30.
• Specific row counts, file sizes, and a complete column list are unavailable from the provided sources.

Provenance

Source

National Aeronautics and Space Administration (NASA), USGS EROS Center, South Dakota State University GSCE.

Collection Method

Generated from composited Landsat Enhanced Thematic Mapper Plus (ETM+) mosaics.

Time Range

2002 to 2012

Freshness

2012-11-30 23:59:59.999000

Geography

Alaska, United States