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The Swisstopo Federal Office of Topography publishes a number of datasets, including very high quality elevation data for the whole of Switzerland at 0.5m and 2m resolutions under the name swissALTI. The data is regularly updated.

Adding 2m Swiss DEM to Open Topo Data

(The procedure is the same for the 0.5m product as the tiles are the same 1km extent).

Make a new folder for the dataset:

mkdir ./data/swisstopo-2m

Download the urls of each tile from swisstopo. When I did this in 2021 there were 43,579 tiles.

Download each tile. wget can do this. Consider doing the downloads sequentially with a rate-limit to avoid overloading their servers.

wget --input-file ch.swisstopo.swissalti3d-xxxxx.csv --no-clobber --limit-rate 1M

Open Topo Data needs files to be named with the lower-left corner coordinates. The files from swisstopo are named like this, but in km instead of metres. I use the following Python script to take a file named like


and rename it to

from glob import glob
import os

dataset_folder = './data/swisstopo-2m/'
pattern = os.path.join(dataset_folder, '**', '*.tif')
paths = sorted(glob(pattern, recursive=True))

for old_path in paths:

    # Extract lower-left corder from filename.
    old_filename = os.path.basename(old_path)
    extent = old_filename.split('_')[2]
    northing = extent.split('-')[1]
    easting = extent.split('-')[0]

    # Convert from km to m.
    northing = int(northing) * 1000
    easting = int(easting) * 1000

    # Build new filename.
    new_filename = old_filename.rsplit('.', 1)[0]
    new_filename = new_filename + f'.N{northing}E{easting}.tif'
    new_path = os.path.join(os.path.dirname(old_path), new_filename)

    # Rename the file.
    os.rename(old_path, new_path)

The final step is adding the to config.yaml:

- name: swisstopo-2m
  path: data/swisstopo-2m/
  filename_epsg: 2056
  filename_tile_size: 1000

Public API

The Open Topo Data public server is full to the brim with elevation data at the moment! Swisstopo is first on the waiting list to be added once I upgrade the server.

2m Swiss elevation data is included in GPXZ