Why does GPS work when underground and under big buildings but radio signals, Wi-Fi, and cell phone signals struggle?

Question

Why does GPS work when underground and under big buildings but radio signals, Wi-Fi, and cell phone signals struggle?

In: 4773

Answer 1

GPS requires a clear view of the sky, and actually changes in how well it works over the course of the day (when more or fewer satellites are overhead).

The location tracking on your phone uses GPS, but also triangulates off of cell towers.

If you’re in a place where cell antennas / boosters have been installed (like in some building basements) or in a tunnel, the location info displayed on your phone is coming from triangulation, not from GPS.

If there is actually no cell service or WiFi service in a location, then your phone has no idea where you are.