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

It definitely doesn’t always work better, but one reason it can work better is because modern GPS, at least for Google, uses multiple sources of location. If you have the settings turned on, they will use GPS, WI-FI signals, which have known locations, Bluetooth signals, and other mobile signals, which also may have known fixed locations.

So because of this, Google maps can continue to estimate your locations if GPS goes out, if it picks up a nearby Wi-fi or something that it already knows the location of.