Python script to download global terrain digital elevation models, SRTM 30m DEM and SRTM 90m DEM.
Global geographic elevation data made easy. Elevation provides easy download, cache and access of the global datasets SRTM 30m Global 1 arc second V003 elaborated by NASA and NGA hosted on Amazon S3 and SRTM 90m Digital Elevation Database v4.1 elaborated by CGIAR-CSI.
Note that any download policies of the respective providers apply.
Install the latest version of Elevation from the Python Package Index:
$ pip install elevation
The following dependencies need to be installed and working:
The following command runs some basic checks and reports common issues:
$ eio selfcheck Your system is ready.
GNU make, curl and unzip come pre-installed with most operating systems. The best way to install GDAL command line tools varies across operating systems and distributions, please refer to the GDAL install documentation.
Command line usage
Identify the geographic bounds of the area of interest and fetch the DEM with the eio command. For example to clip the SRTM 30m DEM of Rome, around 41.9N 12.5W, to the Rome-30m-DEM.tif file:
$ eio clip -o Rome-30m-DEM.tif --bounds 12.35 41.8 12.65 42
For the SRTM 90m DEM use:
$ eio --product SRTM3 clip -o Rome-90m-DEM.tif --bounds 12.35 41.8 12.65 42
The --bounds option accepts latitude and longitude coordinates (more precisely in geodetic coordinates in the WGS84 refernce system EPSG:4326 for those who care) given as left bottom right top similarly to the rio command form rasterio.
If you have installed the packages rasterio and fiona you can clip a DEM on the same extent of any other geospatial data source supported by GDAL and OGR, for example if you have a georeference image MyImage.tif you can clip the corresponding DEM with:
$ eio clip -o MyImage-DEM.tif --reference MyImage.tif # enable with: $ pip install rasterio
The --reference option can take also verctor data as input:
$ eio clip -o MyShapefile-DEM.tif --reference MyShapefile.shp # enable with: $ pip install fiona
The first time an area is accessed Elevation downloads the data tiles from the USGS or CGIAR-CSI servers and caches them in GeoTiff compressed formats, subsequent accesses to the same and nearby areas are much faster.
The clip sub-command doesn’t allow automatic download of a large amount of DEM tiles, please refer to the upstream providers’ websites to learn the preferred procedures for bulk download.
To clean up stale temporary files and fix the cache in the event of a server error use:
$ eio clean
Command line reference
The eio command as the following sub-commands and options:
$ Usage: eio [OPTIONS] COMMAND [ARGS]... Options: --version Show the version and exit. --product [SRTM1|SRTM3] DEM product choice. [default: SRTM1] --cache_dir DIRECTORY Root of the DEM cache folder. [default: /Users/amici/Library/Caches/elevation] --help Show this message and exit. Commands: clean Clean up the product cache from temporary files. clip Clip the DEM to given bounds. distclean Remove the product cache entirely. info Show info about the product cache. seed Seed the DEM to given bounds. selfcheck Audit the system for common issues.
The clip sub-command:
$ eio clip --help Usage: eio clip [OPTIONS] Options: -o, --output PATH Path to output file. Existing files will be overwritten. [default: out.tif] --bounds FLOAT... Output bounds in 'left bottom right top' order. -m, --margin TEXT Decimal degree margin added to the bounds. Use '%' for percent margin. [default: 0] -r, --reference TEXT Use the extent of a reference GDAL/OGR data source as output bounds. --help Show this message and exit.
Defaults can be defined by setting environment variables prefixed with EIO, e.g. EIO_PRODUCT=SRTM3 and EIO_CLIP_MARGIN=10%.
Every command has a corresponding API function in the elevation module:
import elevation # clip the SRTM1 30m DEM of Rome and save it to Rome-DEM.tif elevation.clip(bounds=(12.35, 41.8, 12.65, 42), output='Rome-DEM.tif') # clean up stale temporary files and fix the cache in the event of a server error elevation.clean()
Contributions are very welcome. Please see the CONTRIBUTING document for the best way to help. If you encounter any problems, please file an issue along with a detailed description.
Elevation is free and open source software distributed under the terms of the Apache License, Version 2.0.
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|Filename, Size & Hash SHA256 Hash Help||File Type||Python Version||Upload Date|
(16.3 kB) Copy SHA256 Hash SHA256
|Wheel||py2.py3||Jan 22, 2017|
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|Source||None||Jan 22, 2017|