Provide access to AHN data for Netherlands

[mfsch]

Actueel Hoogtebestand Nederland produces lidar point-cloud data for all of the Netherlands and makes it freely available online. It would be nice to have this data available in PointClouds.jl (originally requested in #1).

The Dataroom page provides an overview of the data and allows for manual browsing of the tiles, with links to download the LAZ files for the complete AHN1, AHN2, AHN3, and AHN4 data sets as well as the in-progress AHN5 data. A service called “Ellipsis Drive” allows browsing this data, and it looks as if they also provide API access. We’d have to verify that this service supports spatial queries to obtain the URLs of the LAZ files, which seem to be hosted on the fundaments.nl domain.

There is also the GeoTiles website, which redistributes the AHN data and provides tiles that are smaller and include some overlap. Ideally, we primarily rely on the “official” data from AHN, but we could support GeoTiles as a secondary provider if necessary.

Note

This issue is primarily to keep track of the information on AHN data, but this does not mean that adding support is currently a priority. Feel free to comment if you’re interested in this data, if you have additional information, or if you want to work on implementing this.