LP DAAC FAQ: NASADEM

[Earthdata - wxedward]

How is NASADEM different from SRTM?

Although NASADEM is derived from Shuttle Radar Topography Mission (SRTM) raw data, one of the primary differences is the use of the latest unwrapping technique and the reliance of auxiliary data to process the raw data, which were not available during the original SRTM processing. Due to an updated unwrapping technique, the results yield fewer voids in the mountainous regions as well as near the peripheral region of the spatial extent. Additional differences can be found on the DEM Comparison Guide.

What is the NASADEM Filename convention?

Each tile covers 1° latitude by 1° longitude of Earth’s surface. Let’s use NASADEM_HGT_n36w112 as an example. The first and second letters, in this case n and w respectively, cover the four corners of Earth’s surface (North, South, East, West). Therefore, n36 covers latitude 36 to 37 North and w112 covers longitude 112 to 113 West. The HGT extension stands for height or elevation.

Does NASADEM have restrictions on reuse, sale, or redistribution?

NASADEM does not have restrictions on reuse, sale, or redistribution. However, users of NASADEM products are encouraged to cite the product. A Citation Generator is available on each NASADEM DOI Landing Page.

Is there a method to download NASADEM data in bulk?

There are multiple methods to download NASADEM in bulk, such as Data Pool, OPeNDAP, and DAAC2Disk, which are all available at the LP DAAC Tools page.

Why can’t I view some NASADEM layers?

NASADEM has five data products, each with a different number of science data layers. The primary data product is the NASADEM_HGT, an elevation data product, which can be displayed in open source as well as commercial geospatial or visualization software. However, some of the auxiliary data layers are binary files; therefore, they must be imported manually to the software.