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

2009 variant is less dense, non-gridded, therefore significantly slower (gdal_grid must be used as an extra step, which is slow). This variant is less robust, but available throughout the country.

Usage

1. Download contour line zip files to this directory. I.e. <NAME>.zip in this directory must contain exactly one file named <NAME>.xyz (compressed).
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.