If you take a moment to search the forum you’ll find this and this:
- Altitude is based on sea level. (In TTN console as well)
- The TTN console fields should be used in stead of manually specifying the coordinates on the gateway. For gateways without GPS TTN will add these coordinates to the gateway metadata for received packets.
- You should not use fake_gps. See 2. People are using it because long ago there was no console where coordinates could be set and it was custom to use fake_gps to provide coordinates. By now people should have switched but bad habits die very slowly…
Bottom line, only have a gateway send GPS information when there is a GPS connected.
PS. Searching the forum is highly recommended. There is a lot of information because others asked the same questions before. Don’t be surprised if ‘the regulars’ stop answering questions that surface repeatedly because people can’t be bothered to search…