NASADEM Global Elevation Data at 1 Arc Second Resolution

NASADEM Merged DEM Global 1 arc second V001 provides global elevation data derived from the Shuttle Radar Topography Mission (SRTM). The dataset covers land between 60° N and 56° S latitude, accounting for about 80% of Earth's total landmass. It was produced by NASA's Land Processes DAAC using SRTM telemetry data from the 2000 STS-99 mission, enhanced with ASTER GDEM and ICESat GLAS ground control.

Use Cases

• Model hydrological flow and watershed boundaries using the DEM layer elevation values.
• Assess terrain roughness or slope for infrastructure planning by analyzing elevation gradients across tiles.
• Generate updated water body masks for land cover classification using the SRTM water mask layer.
• Evaluate data source reliability for specific pixels by referencing the NUM layer indicating scene count and source.
• Create global topographic maps and visualizations from the 1 arc second resolution elevation grid.

Strengths

• Global coverage of approximately 80% of Earth's landmass between 60° N and 56° S.
• 1 arc second spatial resolution provides detailed elevation information.
• Data incorporates multiple sources including SRTM, ASTER GDEM, and ICESat GLAS for improved accuracy.
• Distributed in standardized 1 degree by 1 degree tiles for easy regional access.

Limitations

• Data is derived from a mission flown in February 2000, representing a single snapshot and may not reflect recent terrain changes.
• Coverage excludes polar regions above 60° N and below 56° S.
• Specific metrics on vertical accuracy, row count, or file size are not provided in the description.

Provenance

Source

NASA Land Processes Distributed Active Archive Center (LP DAAC), derived from Shuttle Radar Topography Mission (SRTM).

Collection Method

Generated from SRTM radar interferometry telemetry, reprocessed with ASTER GDEM, ICESat GLAS ground control, and other DEMs for void filling and geoid reference.

Time Range

Primary data source from the STS-99 mission launched on February 11, 2000.

Freshness

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Geography

Global land coverage between 60° North latitude and 56° South latitude.