It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Some features of ATS will be disabled while you continue to use an ad-blocker.
The HAARP facility can also be used to produce low frequency signals. These signals are identical in all respects to more commonly known broadcast signals like AM, FM and Television except that they have a lower frequency, typically less than 15 kHz. Signals in this frequency range can be produced in the ionosphere by modulating the HAARP transmitters at these frequencies. Research utilizing low-frequency signals is exploring several possible applications. One of these areas is geophysical prospecting, that is, the search for underground mineral resources. In this highly sophisticated field, one of the conventional approaches takes advantage of naturally occurring signals originating in the upper ionosphere that penetrate into the Earth's crust and reveal information about underground structure. This technique is limited because the natural signals occur in random fashion. In contrast, the low frequency signals produced using HAARP, although not as strong as those occurring in nature, are known precisely in time and phase, and more sensitive detection techniques can be utilized to great advantage to yield potentially significant improvements in the field of geophysical prospecting.
The detection of underground structure is important for national security reasons as well. Existing military surveillance systems can monitor potentially threatening activities above ground. But there is no simple way to detect clandestine activities underground. The possibility that such activities might be aimed at developing weapons of mass destruction is a major concern. Congress has assigned responsibility to the Department of Defense to address this national security issue of counterproliferation. The same techniques being explored and developed for the detection of mineral resources are also applicable to this problem. In an early experiment, very encouraging results were obtained when a known underground tunnel was successfully detected. Further work is underway to refine this capability.