Garmin have great system where you can buy map over an area. And some of these maps are in “high” resolution, that is in 1:20000 Buildings, pluming and some powercables are put down on the map. Here in Norway Garmin have collected data from the county, therefore it is very accurate.
Sometimes when i`m flying i dont have internet or phone connection but would love an accurate map.
Q: Is it possible to integrate Garmin maps with Apm ground station ?
An if you are thinking of try, you can borrow my map since it is quite expensive
Why not just cache the Google or other supported maps for the area where you are going to fly - then you can plan missions or fly missions without internet?
Google maps are far from accurate outside of big population centers.
I don’t know about Garmin’s format but GeoTIFF would be nice to have and it’s fairly common. IIRC, USGS has free HQ maps published in GeoTIFF and Finland just did the same. 1:50k Topo and aerial imagery for Finland are now available in the public domain.