[Qgis-user] offline basemap in Qfield

[Greg Troxel]

"Huesmann, Michaela via QGIS-User" <qgis-user at lists.osgeo.org> writes:

> I would like to record data with Qfield using my Android mobile
> phone. In order not to use too much data volume, the base maps should
> be downloaded via WiFi beforehand so that they can be used offline
> outside. However, GPS must be used for orientation during the mobile
> recording process. My questions about this:
> 1. Which map material for Germany can be used offline as  base map in my qfield project and how can I download it?
> 2. How do I ensure that the offline maps are used outside and that no download takes place while I navigate with GPS?

You didn't explain

  - How much data is too much?

  - What happens in terms of data if you just use an OSM mapnik basemap
    + in particualr, what if you open qfield on wifi and pan around to
      all the places you are going to be, to cause it to fetch data.
      Note that OSM requires that users of its tile service cache data
      for a reasonable period of time (7 days?), and thus QField should
      be caching.
      
  - What size area you are operating in?

I mean to ask "are you really sure you have a problem that needs
solving?"

It is straigthforward to make a raster image of a small area and use
that via "copy" in the now-oddly-named "cable" export.  (I use nextcloud
to exchange bits, not an actual cable...)

Making something that can cover a larger area at varying resolution
probably involves some sort of tiles-in-sqlite format.

In general, the only map data that I'm aware of with licensing that
permits this sort of use is OpenStreetMap, and in the US, government
data from the federal government and a number of states.  (I have no
knowledge.de, but I'd expect similar -- OSM and maybe government.)