Clearsky

Try it: drop a GPS jammer

Click anywhere on the map to put a jammer there. Clearsky will show which planes on the map would lose GPS.

Antenna height 50 m Transmitter power (farthest reach) 350 km

Radio can't bend around the Earth, so a ground jammer reaches high planes much farther than low ones. Turn on 3D in Layers to see the bowl-shaped zone.