Swisstopo OSRM Mapper

Description

This project generates a shadow or terrain map as a TIFF file for a selected location in Switzerland using elevation data from the swisstopo API. With a single command, users can define a region using a bounding box, fetch the necessary terrain data, and produce an accurate shadow or terrain visualization.

How it works

Batch scripts

• generate_alti.bat: Downloads and merges altitude (elevation) data from GeoTIFF files. Uses gdal_calc and gdalwarp to convert data.

• generate_shadows.bat: Downloads and processes shadow and terrain surface data. Uses GRASS GIS tools like r.sun and r.horizon to compute shadows.

• importing_alti3D.bat and importing_surface.bat: Those are seperate files, which import altitude data (alti) and surface data into GRASS GIS using r.import.

• start_program.bat: This script begins the whole process. It sets the settings of the final outcome. It calls generate_alti.bat or generate_shadows.bat based on the user selection.

Python scripts

• download_tiffs.py: Reads a JSON file containing geospatial dataset information. Extracts and downloads TIFF images from URLs.

• find_next_link.py: Finds the "next" download URL in the dataset API. Continues downloading more TIFF files if multiple pages exist.

• merge_tiffs.py: Merges multiple TIFF images into a single file. Uses gdal_merge to process the images.

wget.exe

wget.exe is a command-line tool for downloading files from the internet. In this case it needs to download and fetch geospatial data as GeoTIFF files from the swisstopo API.

Requirements

• Python 3.x
• GRASS GIS 8.4
• GDAL

How to use

You must execute the test_rappi.bat script in the GRASS GIS Shell. You can modify the bounding box and the filename inside the test_rappi.bat file. Also set the output_function to either "shadow" or "alti" based on what you want to generate. Choose whether to generate shadows alone or include horizon data.

The file will download the tif files out of the swisstopo database on your computer under the files folder, which will be created once you run the script. Based on the size of your selected location, it could be several gb large. You will find the generated shadows or altitude files as TIFF files inside the output folder.