The most prominent instrument at the HAARP Station is the Ionospheric Research Instrument (IRI), a high-power radio frequency transmitter facility operating in the high frequency (HF) band.
The IRI is used to temporarily excite a limited area of the ionosphere.
Other instruments, such as a VHF and a UHF radar, a fluxgate magnetometer, a digisonde, and an induction magnetometer, are used to study the physical processes that occur in the excited region.
Work on the HAARP Station began in 1993.
The current working IRI was completed in 2007, and its prime contractor was BAE Systems Advanced Technologies.
As of 2008, HAARP had incurred around $250 million in tax-funded construction and operating costs.
HAARP has been blamed for a range of events, including numerous natural disasters.
The HAARP project directs a 3.6 MW signal, in the 2.8–10 MHz region of the HF (high-frequency) band, into the ionosphere. The signal may be pulsed or continuous.
Then, effects of the transmission and any recovery period can be examined using associated instrumentation, including VHF and UHF radars, HF receivers, and optical cameras.
According to the HAARP team, this will advance the study of basic natural processes that occur in the ionosphere under the natural but much stronger influence of solar interaction, and how the natural ionosphere affects radio signals.
This will enable scientists to develop methods to mitigate these
effects to improve the reliability or performance of communication and
navigation systems, which would have a wide range of uses, civilian and
military, such as an increased accuracy of GPS navigation, and advances
in underwater and underground research and applications.
This may lead to improved methods for submarine communication, or an ability to remotely sense and map the mineral content of the terrestrial subsurface, and perhaps underground complexes, of regions or countries, among other things.
The current facility lacks the range to reach these countries, but the research could be used to develop a mobile platform.