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.