stud/contours/README.md

Countour line generator from LIDAR data

This accepts two kinds of contour data:

2017 variant: y, x, z, separated by commas:

6062999.75,584000.75,88.07

Recommended whenever available. It is more dense, gridded (thus much faster), but not available outside major cities.

2009 variant: x, y, z, separated by one or more spaces:

 501991.670  6150000.000  57.689

Non-gridded, therefore significantly slower (gdal_grid must be used before making contours, which is slow). However, available throughout the country.

Usage:

1. Download contour lines to zip files in this directory.
2. Adjust BOUNDS and VARIANT in config.mk.
3. Run make -j$(nproc) smooth_<X>.gpkg. This will output a geo-package with contour lines every X meters. X can be fractional (e.g. smooth_2.5.gpkg).
4. Optional: you may generate a raster image with layer2img.py.

Dependencies for a Linux system:

• docker
• psql (client only)
• gdal-bin
• unzip
• awk

Example

License

Code in this directory is public domain.