Space Studies Board Annual Report 2013 (2014) / Chapter Skim
Currently Skimming:
5.3 Opportunities for High-Power, High-Frequency Transmitters to Advance Ionospheric/Thermospheric Research: Report of a Workshop: A Report of the SSB Ad Hoc Committee on the Role of High-Power, High-Frequency-Band Transmitters in Advancing Ionospheric/Thermospheric Research: A Workshop
5.3 Opportunities for High-Power, High-Frequency Transmitters to Advance Ionospheric/Thermospheric Research: Report of a Workshop: A Report of the SSB Ad Hoc Committee on the Role of High-Power, High-Frequency-Band Transmitters in Advancing Ionospheric/Thermospheric Research: A Workshop
Pages 42-51
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 42... ...
. research areas that will be explored include generation of very low and extremely low frequency waves, generation of geomagnetic field-aligned irregularities, electron acceleration, and investigation of upper atmospheric processes."4 Figure S.2 illustrates operation of the HAARP transmitter -- known as an ionospheric "heater" because most of the transmitted energy goes into heating ionospheric electrons.
|
From page 43... ...
At the workshop, the Navy's interest in HAARP was attributed to the prospects to use the ionosphere as an antenna to generate extremely low-frequency (ELF) waves for global submarine communication, while the Air Force interest included applications such as over-the-horizon radar and attempts to study the effects of injecting ULF, ELF, and VLF waves into the radiation belts in order to affect the lifetimes of "killer" million-electron-volt electrons that would otherwise disable low Earth orbit satellites.6 Those applications were not widely discussed in this unclassified workshop, although some of them are mentioned in Chapter 4.
|
From page 44... ...
At various points in this workshop, participants proposed ways to make the facility more welcoming and user-friendly in the future and better coordinated with the CEDAR community. Chapter 6 describes some of these proposals; in particular, NSF representatives at the workshop discussed their desire to move the Poker Flat, Alaska, advanced modular incoherent scatter radar (PFISR)
|
From page 45... ...
. Recent experiments at HAARP, some only possible since 2007 when the facility was completed and operation at the full design power became possible, have resulted in observations of phenomena that multiple participants characterized as new and exciting: • The creation of artificially ionized layers descending from near the F-peak to altitudes close to 150 km; • The capability of sustaining high-density plasma clouds in the F-region for more than 3 h, ending only when the heater was turned off; • Virtual antenna ULF/ELF generation with modulated F-region heating without requiring the presence of the natural electrojet; • Triggered emissions by injection of ELF/VLF waves in the radiation belts; and • eneration of very small size irregularities capable of enhancing total electron concentration (TEC)
|
From page 46... ...
During the workshop, Dennis Papadopoulos noted that the large number of satellite missions with excellent diagnostic instru ments, including the Van Allen Probes, the Canadian e-POP/CASSIOPE,9 the Russian Resonance,10 the Air Force 8 DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) was a microsatellite mission of the French space agency CNES that ended in late 2010.
|
From page 47... ...
Studies of the nonlinear interaction of HF radio waves with the ionosphere using recently developed powerful and agile ionospheric heaters, such as the EISCAT heater and more recently the completed HAARP heater, have resulted in the development of novel techniques that workshop presenters, including Herbert Carlson, described as potentially transformational in their implications for understanding ITM regions and their coupling. According to Carlson and other participants familiar with recent active experiments, science areas impacted by the novel recent discoveries at EISCAT and HAARP include the following: • Radio science.
|
From page 48... ...
• Numerous participants, including Richard Behnke, Robert Robinson, Robert McCoy, Dennis Papadopoulos, Paul Bernhardt, Todd Pedersen, Herbert Carlson, David Hysell, and Brett Isham, stated that moving an ISR to the HAARP site would provide critical diagnostic information that would help resolve physics-related issues involving ionosphere-thermosphere diagnostics, the physics of artificial ionization, and the details of virtual antenna operation. • Other participants noted that HAARP could be operated as a radar by upgrading the existing radar receiver to an imaging array.
|
From page 49... ...
It was argued by Dennis Papadopoulos and others that with its location in the subauroral zone during weak and moderate substorms, investigations conducted with the HAARP facility can advance understanding of key space weather processes in subauroral geospace, as well as mimic aspects of substorm dynamics, by inducing effects similar to the ones created during natural events. Such HF-driven effects were said to include (1)
|
From page 50... ...
Herbert Carlson stated that the involvement of NSF, brought in via the inclusion of the current PFISR radar, would also contribute to opening HAARP up to additional communities of researchers new to the possibilities and potentials of using active HF techniques.21 18 See Joint Services Program Plans and Activities, Air Force Geophysics Laboratory, and Navy Office of Naval Research (1990)
|
From page 51... ...
:393-394. Joint Services Program Plans and Activities, Air Force Geophysics Laboratory, and Navy Office of Naval Research.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.