

One interesting alternative would be the Visual Positioning System (VPS) that Niantic has built from Pokemon go player data. Basically you can take a picture outside and your phone will know exactly where you are:
https://www.nianticspatial.com/locate#vps
Too bad they’re getting close to being bought out by a company that’s notorious for squeezing out every penny from their player base.
I doubt it would work well, but with enough training data it would be able to pick up on some areas. Especially if there are large landmarks in the frame (mountains/hills/rivers, etc.).