Military HF Ionosphere study - USAF News Article
There are links on the articles page to Hi-res photos of the dipoles and the location
of their facility.
From the article...
Mr. Battis described the unique nature of the HAARP array, consisting of 180
transmitters distributed over 35 to 40 acres of land, with a frequency range of 2.65
to 10 megahertz.
http://www.af.mil/news/story.asp?id=123193118
Military scientists study ionosphere
by Bob Freeman
Special to American Forces Press Service
3/3/2010 - WASHINGTON (AFNS) -- At a facility in a remote part of south-central
Alaska, the largest radio transmitter on Earth sends high-frequency signals into the
ionosphere to help scientists better understand the influence of charged particles on
radio communications and satellite surveillance systems.
Surprisingly, it also is able to create a mini-ionosphere.
"The High Frequency Active Auroral Research Program, a program known as HAARP, is
basically a joint Air Force-Navy program to investigate ionospheric physics and radio
science," explained James Battis, HAARP program manager at the Air Force Research
Laboratory, during a Feb. 24 interview on Pentagon Web Radio's audio webcast "Armed
with Science: Research and Applications for the Modern Military."
Mr. Battis was joined in the interview by Craig Selcher, HAARP program manager at the
Naval Research Laboratory, and Todd Pedersen, a senior research physicist at AFRL.
"The ionosphere is a region of the upper atmosphere where there are a significant
number of charged particles," Mr. Pedersen said. He explained that energy from the
sun, particularly in the ultraviolet wavelengths, strikes atmospheric gas molecules
and atoms with enough force to dislodge electrons. This results in a field of
negatively charged electrons and positively charged atoms and molecules (ions),
maintained in a plasma state, which conducts electrical currents and responds to
electric and magnetic fields.
Mr. Battis mentioned that radio waves passing through the ionosphere are affected by
the charged particles. "This can affect things like the quality of the signal from a
satellite to the ground, or short-wave communications from ground to ground," he said.
He added that the signals from satellite-based surveillance and positioning systems
also can be affected by the ionosphere.
"When the signals from GPS come down (from the satellite), their paths are actually
deflected by the structure of the ionosphere," he said, "and some GPS errors are due
to distortions created by the ionosphere." He explained that while these errors may
not be significant to the average user, they can be significant for precise military
positioning. "That's one of the reasons (the Defense Department) is interested," he
noted.
But the scientists all agreed that communications are the major reason for Defense
Department interest.
"These are the transmissions which are used to communicate with aircraft and
satellites, so the Air Force is interested largely in effects of the ionosphere on
communications," Battis said.
Mr. Selcher agreed. "We have ships all over the globe that we want to be in contact
with at all times, so any effect the ionosphere has on communications is something
that we want to study," he said.
Mr. Battis noted that the research conducted by HAARP will benefit civilian
communication systems as well, including those supporting civil aviation and ground
communications.
"Satellite radio and satellite television can also be impacted by naturally occurring
ionospheric conditions," Mr. Selcher added. "And trying to understand those is to
begin to learn to predict, and maybe to (improve), the problem."
Mr. Battis described much of the previous ionospheric research as passive, with the
evaluation of ionospheric effects based on the quality of reception of a normally
transmitted radio signal.
"The radio waves we transmit from the array at our facility actively create processes
and interactions with the particles in the ionosphere," he said. "Hopefully, we can
learn what the responses are and how to use them to improve transmissions through the
ionosphere."
"We have radio-wave sensors which send waves up to the ionosphere and listen for a
reflection or an echo off something up there," Mr. Pedersen remarked. "And we have
passive sensors that will listen to waves produced in the ionosphere, and also
optical sensors."
Mr. Pedersen explained that when energy is directed at the ionosphere, some of it
eventually comes back in the form of radio waves and some in the form of optical
emissions.
"When these electrons get moved around by the electric field, they ultimately run
into molecules up there, and when they have enough energy they'll become excited and
give off light, just like the inside of a fluorescent light bulb," he said.
Mr. Battis and Mr. Selcher said that the radio waves emitted from the HAARP array
create reactions that mimic natural processes in the ionosphere, but they are more
controlled and their time and frequency input is measured, allowing the researchers
to differentiate them from natural occurrences and better understand the processes at
play.
"You can actually repeat the experiment again and again to verify that you're getting
the right data and that the data means what you think it means," Mr. Selcher said.
Mr. Battis described the unique nature of the HAARP array, consisting of 180
transmitters distributed over 35 to 40 acres of land, with a frequency range of 2.65
to 10 megahertz.
"We can actually direct the signal within about 15 degrees of the zenith and move the
signal in time," he said. "We can paint the sky. Similar facilities are typically
restricted to three or four frequencies in that band, whereas we're able to do more
continuous frequencies."
"That allows you to really expand the kind of experiments that you can do," Mr.
Selcher added. "You can start sweeping the beam around in space, and you can change
frequencies to determine if there's a frequency that has a stronger interaction with
the ionosphere."
Mr. Pedersen described a surprising advance in the use of HAARP transmitters. He
explained that at full power, HAARP is energetic enough that its signals not only
light up the gas molecules, they're also able to knock additional electrons off,
creating small areas of artificial plasma.
"Sunlight does that, and that's how we get the ionosphere in the first place," Mr.
Pedersen said. "The aurora also does it. Electrons come shooting in from the aurora,
from far out in space, hit the gas molecules, knock electrons off and create a
temporary ionosphere for the duration of time the aurora is there," he explained.
In short, HAARP is able to create a small addition to the ionosphere. "We can add to
the ionosphere enough that we can actually start doing experiments in that little
spot of plasma that we created from the transmitter," Mr. Pedersen said.
Mr. Pedersen remarked that the next step was to figure out exactly what's happening
in this artificial plasma and how to control it.
"This field has been data-starved for many, many years," Mr. Selcher noted, "because
there weren't enough facilities that had the kind of power that HAARP has." He
explained that theorists proposed many ideas to explain ionospheric interactions, but
the data wasn't available to support them. HAARP is changing that.
"It's a nice position to be in as an experimentalist," he said.
(Courtesy of American Forces Press Service)
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