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Note: This document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade, and read the current manual page.

NAME - Creates a DEM from 1 arcsec NASADEM tiles.


raster, import, SRTM

SYNOPSIS --help [-z] [version=string] [layer=string] output=name [username=string] [password=string] [url=string] [local=name] [region=xmin,ymin,xmax,ymax] [method=string] [resolution=float] [memory=integer] [--overwrite] [--help] [--verbose] [--quiet] [--ui]


Create zero elevation for missing tiles
Allow output files to overwrite existing files
Print usage summary
Verbose module output
Quiet module output
Force launching GUI dialog


NASADEM version
Options: NASADEM_HGT.001
Default: NASADEM_HGT.001
NASADEM layer to import
Options: hgt, num, swb
Default: hgt
hgt: Void-filled DEM
num: Number of scenes
swb: Updated SRTM water body data
output=name [required]
Name for output raster map
Username for authentication
Password for authentication
Base URL to fetch NASADEM tiles
Local folder with NASADEM tiles
Use local folder instead of URL to retrieve NASADEM tiles
Import subregion only (default is current region)
Format: xmin,ymin,xmax,ymax - usually W,S,E,N
Resampling method to use for reprojection (required if location projection not longlat)
Options: nearest, bilinear, bicubic, lanczos, bilinear_f, bicubic_f, lanczos_f
Default: bilinear_f
nearest: nearest neighbor
bilinear: bilinear interpolation
bicubic: bicubic interpolation
lanczos: lanczos filter
bilinear_f: bilinear interpolation with fallback
bicubic_f: bicubic interpolation with fallback
lanczos_f: lanczos filter with fallback
Resolution of output raster map (required if location projection not longlat)
Maximum memory to be used (in MB)
Cache size for raster rows
Default: 300

Table of contents

DESCRIPTION imports all NASADEM tiles covering the current region or region extents given with the region option into GRASS and patches the tiles together.

Cited from

"NASADEM extends the legacy of the Shuttle Radar Topography Mission (SRTM) by improving the digital elevation model (DEM) height accuracy and data coverage as well as providing additional SRTM radar-related data products. The improvements were achieved by reprocessing the original SRTM radar signal data and telemetry data with updated algorithms and auxiliary data not available at the time of the original SRTM processing."

In total, 14,520 NASADEM tiles are available. imports data from NASADEM_HGT.001, or from a local copy of these data provided with the local option.

There are three different layers available in the NASADEM_HGT.001 product: hgt, num, and swb, each of these layers can be imported with with the layer option. Importantly, for the NASADEM tiles download a user registration is needed at

In the earthdata user profile, two specific applications must be approved in the "My application" tab:


Import of NASADEM_HGT.001 covering the current computational region:
# run in LatLong location - Sicily East, Italy
g.region n=39 s=37 w=14 e=16 res=0:00:01 -p

# use own credentials here user="my_nasa_user" password="my_nasa_pw" output=nasadem_sicily_1arc memory=2000
r.univar nasadem_sicily_1arc example
Figure: Eta volcano (Sicily, Italy) shown in NVIZ


The Shuttle Radar Topography Mission homepage at NASA's JPL (see also MEaSUREs Data Product Table - SRTM).

The NASADEM_HGT.001 product page.


M. Neteler, 2005. SRTM and VMAP0 data in OGR and GRASS. GRASS Newsletter, Vol.3, pp. 2-6, June 2005. ISSN 1614-8746.


Markus Metz
Reprojection support: Anika Bettge, mundialis


Available at: source code (history)

Latest change: Monday Jan 30 19:52:26 2023 in commit: cac8d9d848299297977d1315b7e90cc3f7698730

Note: This document is for an older version of GRASS GIS that will be discontinued soon. You should upgrade, and read the current manual page.

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