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 doesn’t work well underground. GPS is ultra-high frequency. Ironically your phone will look for WiFi and Cell signals and has a database of expected GPS coordinates based on the signals that is sees. These aren’t super precise but since these WiFi signals have an expected GPS location your phone can guess a triangulation of your location.

Most electronics are ultra high frequency and don’t go through things very well. Low frequencies like AM radio and ultra-low frequencies are such that they can more easily go through the ground.