The ERP numbers are misleading. I've read elsewhere that the transmitter's output at the antenna connector is on the order of a half watt.
KiloWatts and GigaHertz? Ummm... just wow. Other than big mother military radars, that much power at that high a frequency is.... unusual.
It's suspicious. Because at gigahertz you definitely cannot go above the radio horizon even at very high powers. So it must be trying to either do non-communications tasks, or point upwards into space, so it can do comms with things in orbit.