Satellites give better performance but there is no reason why a ground based system can't work just as well. LORAN gave accuracy to a hundred metres or so acros

Satellites give better performance but there is no reason why a ground based system can't work just as well. LORAN gave accuracy to a hundred metres or so across a good portion of the globe https://timeandnavigation.si.edu/navigating-air/navigation-at-war/new-era-in-time-and-navigation/loran https://timeandnavigation.si.edu/navigating-air/navigation-a... Most location services on a phone are performed using WiFi and cellular data rather than GPS except in remote areas. With modern technology an array of autonomous radio transmitter buoys could give the same accuracy as GPS.