Originally Posted by
fastair
Except the gps function inside a building isn’t gps, it’s just an approximation from cell towers. I work at the airport and when I track mine (inside) it often shows in the middle of the tarmac. Location accuracy declines without direct line of sight to satellites
Not entirely true. You need to check how strong the signals the phones are getting. In most phones WiFi location + GPS can get you very accurate locations.
I'm sitting in 3rd story of a 5 story apartment building and getting full GPS lock. Just because you don't have clear sky visibility and you're indoors doesn't mean you can't get a GPS lock.