HAARP Technology

The High Frequency Active Auroral Research Program (HAARP) is an investigation project to "understand, simulate and control ionospheric processes that might alter the performance of communication and surveillance systems."^[citation] Started in 1993, the project is proposed to last for a period of twenty years. The project is jointly funded by the United States Air Force, the Navy, the University of Alaska and Defense Advanced Research Projects Agency^{[citation needde]} (DARPA). The system was designed and built by Advanced Power Technologies, Inc. ^{[citati needdde]} (APTI) and since 2003, by BAE

HAARP's main goal is basic science research of the uppermost portion of the atmosphere, known as the ionosphere. Essentially a transition between the atmosphere and the magnetosphere, the ionosphere is where the atmosphere is thin enough that the sun's x-rays and UV rays can reach it, but thick enough that there are still enough molecules present to absorb those rays. Consequently, the ionosphere consists of a rapid increase in density of free electrons, beginning at ~70 km, reaching a peak at ~300 km, and then falling off again as the atmosphere disappears entirely by ~1000 km. Various aspects of HAARP can study all of the main layers of the ionosphere.

The profile of the ionosphere, however, is highly variable, showing variations minute-to-minute changes, diurnal changes, seasonal changes, and year-to-year changes. This becomes particularly complicated near the Earth's poles, where a host of physical processes (like auroral lights) are unlocked by the fact that the alignment of the Earth's magnetic field is nearly vertical.

On the other hand, the ionosphere is traditionally very difficult to measure. Balloons cannot reach it because the air is too thin, but satellites cannot orbit there because the air is still too thick. Hence, most experiments on the ionosphere give only small pieces of information. HAARP approaches the study of the ionosphere by following in the footsteps of an ionospheric heater called EISCAT near Tromsø, Norway. There, they pioneered exploration of the ionosphere by perturbing it with radio waves in the 2-10 kHz range, and studying how the ionosphere reacts. HAARP performs the same functions but with significantly more power.

Some of the main scientific findings from HAARP include:

1. Generation of very low frequency by modulated heating of the auroral electrojet, useful because generating VLF waves ordinarily requires gigantic antennas.
2. Production of weak luminous glow (below what you can see with your eye, but measurable) from absorption of HAARP's signal.
3. Production of ultra low frequency waves in the 0.1 Hz range, which are next to impossible to produce any other way.
4. Generation of whistler-mode vlf signals which enter the magnetosphere, and propagate to the other hemisphere, interacting with Van Allen radiation belt particles along the way.
5. VLF remote sensing of the heated ionosphere.

Research at the HAARP includes:

1. Ionospheric heating
2. Plasma line observations
3. Stimulated electron emission observations
4. Gyro-frequency heating research
5. Spread F observations
6. Airglow observations
7. Heating induced scintillation observations
8. VLF and ELF generation observations
9. Radio observations of meteors
10. Polar mesospheric summer echoes: Polar mesospheric summer echoes (PMSE) have been studied using the IRI as a powerful radar, as well as with the 28 MHz radar, and the two VHF radars at 49 MHz and 139 MHz. The presence of multiple radars spanning both HF and VHF bands allows scientists to make comparative measurements that may someday lead to an understanding of the processes that form these elusive phenomenon.
11. Research on extra-terrestial HF radar echos: the Lunar Echo experiment (2008).