HAARP (High-Frequency Active Auroral Research Program) is a high-powered radio transmission research facility jointly operated by the US Navy, Air Force and several universities. Because of the high secrecy surrounding the government HAARP project, many theories have risen trying to explain what HAARP is and does. Most of them are simply wild speculations, based on fears about what "they are doing up there." It is the purpose of this article to provide sufficient technical expertise to dispel the mystery.
The above HAARP signal was monitored on 3.39 MHZ and recorded in San Jose, California, about 5,000 miles from the transmitter in Gakona, eastern central Alaska. At that distance and frequency, the signal can only be heard during the night after two F-layer ionospheric skips. Some short-term signal fading over the signal path may be the cause for the variations in the smooth roll-off in the amplitude from 1 sec to the end of the pulse at 6.25 secs. These loud 6 second pulses are usually repeated with a quiet 15 or 30 second pause between pulses.