HAARP for Dummies

The High frequency Active Auroral Research Program (HAARP) is an Air Force military program focused on the study of upper atmospheric and solar-terrestrial physics and Radio Science. The HAARP program operates a major Arctic ionosphere research facility on an Air Force owned site near Gakona, Alaska. -- source www.haarp.alaska.edu

 
HAARP generates microwaves that stimulate the ionosphere using  ELF and VLF receivers, magnetometers, riometers, a UHF diagnostic radar and optical and infrared spectrometers and cameras used to record the auroral chances in the ionosphere.

HAARP also uses UHF radar which is why we all had to switch over to digital, freeing up UHF and VHF waves for other uses.