How Google Maps tracks you in a tunnel

How does Google Maps still track you in a tunnel when GPS disappears? Your phone estimates your position from its accelerometer, gyroscope and compass until GPS comes back. The longer the tunnel, the harder it gets, and the same idea is used in airplanes when satellites aren't available. Idea and structure: Tiff in Tech's Short on the same question. Sources are in the pinned comment. #shorts #googlemaps #technology