1 HEATING expands the mind EISCAT training course.
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Transcript of 1 HEATING expands the mind EISCAT training course.
1
HEATINGHEATINGexpands the mindexpands the mind
EISCAT training courseEISCAT training course
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The pastThe pastG. Marconi (1874 -1937)
Nobel Prize 1909
Earth
There had to be a reflecting layer in order to explain his trans-Atlantic radio wave connection.
Reflecting layer at 100-200 km altitude (the ionosphere)
Radio Sender
Receiver
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Tesla developed high-frequency high-power generators
The pastThe past N. Tesla (1856-1943)
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The pastThe pastAt the same time as Marconi, Tesla wanted to transmit energy as well as information using wireless radio waves.
He built a transmission tower for this pupose.
However, his work had little to do with modern ionospheric research.
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The The pastpast
Geometry of the
Luxembourg effect
(Tellegen, 1933)
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EISCAT consists of much more than just radars. It possesses the world‘s largest high-frequency (HF) ionospheric modifi-cation facility, called HEATING or simply the HEATER.
Built by the Max-Planck-Society in the late 1970s, it passed to EISCAT in 1993.
EISCAT EISCAT mainlandmainland
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A geographic overview of the EISCAT radar, HEATING & SPEAR HF facilities and CUTLASS coherent scatter radars
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Antenna 1
Antenna 2
Antenna 3
Transmitter
The Heating facility at The Heating facility at TromsøTromsø
Control
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Tromsø HEATING facility layoutTromsø HEATING facility layout
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HEATER control house with EISCAT radars in the background
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A single HEATING antennaA single HEATING antenna
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An antenna arrayAn antenna array
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Transmitters Transmitters during construction: 6 of 12
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Only 50 km of home-madealuminium RF coaxial transmission lines with mechanical switches
CoaxCoax
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Thermal expansion:Thermal expansion: One of many detours
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2 Antennas give a broad beam
4 Antennas give a narrower beamwith more power in the forwarddirection and less power in allother directions.
Effective Radiated PowerEffective Radiated Power = Radiated power Antenna gainAt HeatingAt Heating: 300 MW = 1.1 MW 270 for low gain antennas1.2 GW = 1200 MW = 1.1 MW 1100 for high gain antenna
Beam formingBeam forming
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•1970: Platteville, Colorado•1975: SURA (Nizhni Novgorod), Russia•~1980: Arecibo (Puerto Rico), Tromsø (Norway), HIPAS (Alaska) •1995: HAARP (Alaska)•2003: SPEAR (Svalbard)
World World overviewoverview
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A comparisonA comparisonHEATINGHEATING SPEARSPEAR HAARPHAARP (final)
Power (MW):1.1 0.192 3.3
Antenna 24 and 30 16 & 22 30Gain (dB):
ERP (MW): 300 & 1200 7.6 & 30 3600
Freq. (MHZ): 3.9-5.4 & 5.4-8 2-3 & 4-6 2.8-10
Polarisation: O & X O & X O & X
Beam only north-south any anySteering: relatively slow fast fast
Diagnostics: KST ESR ?CUTLASS CUTLASS KODIAKDynasonde ? Digisonde
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The ionosphereThe ionosphere
Fc = 8.98*sqrt(Ne) for O-mode
Fc = 8.98*sqrt(Ne) + 0.5*Be/m for X-mode
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A comparison of frequency range and effective radiated power of different facilities
1GW
100 MW
10 MW
SPEAR
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Why do we need the HEATING Why do we need the HEATING facility?facility?
Why?: HF facilities are the only truetrue active experiments in the ionosphere because the plasma may be temporarily modified under user control.
Operations: ~200 hours per year (1 year=8760 hours), mostly in user-defined campaign mode.
Experiments can be divided into 2 groups:
Plasma physics investigations: the ionosphere is used as a laboratory to study wave-plasma turbulence and instabilities.
Geophysical investigations:ionospheric, atmospheric or magnetospheric research is undertaken.
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The Incoherent Scatter RadarThe Incoherent Scatter Radar Spectra with Ion and Plasma lines Spectra with Ion and Plasma lines corresponding to ion-acoustic waves and Langmuir wavescorresponding to ion-acoustic waves and Langmuir waves
Langmuir turbulence, the parametric decay instability:
e/m pump(0 ,0) Langmuir(0 - ia,-k) + IonAcoustic(ia ,k)
Langmuir(0 - ia,-k) Langmuir(0 - 2ia,k) + IonAcoustic (ia,-2k)
The component of the pump electric field parallel to the Earth's magnetic field is what matters.
Thermal resonance instability:
e/m pump + field-aligned electron density striation electrostatic wave (UH)
Upper hybrid (UH) resonance condition: 02 = p
2 + e2
The component of the pump electric field perpendicular to the Earth's magnetic field is what matters.
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PLASMA TURBULENCEPLASMA TURBULENCE
HF on
HF off
UHF ion line spectra
12 Nov 2001 5.423 MHz ERP = 830 MW O-mode
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The UHF radar observes HF pump-induced plasma turbulence
5.423 MHzERP = 1.1 GWO-mode
PLASMA TURBULENCEPLASMA TURBULENCE
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PLASMA TURBULENCEPLASMA TURBULENCE
Z-mode penetration
of the ionosphere
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HF pump-induced magnetic field-aligned electron density irregularities (up to ~5%) causes coherent radar reflections and anomalous absorption (by scattering) of probing signals.
StriationsStriations
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HF induced F-region CUTLASS radar backscatter
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Amplitude of radio waves received from the satellite
StriationsStriations
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After HF pump off, the irregularities decay with time
StriationsStriations
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Tromsø
HF induced E-region STARE backscatter
(144 MHz)
31Heater on
Artificially raised electron temperatures
16 Feb 1999
4.04 MHzERP = 75 MWO-mode
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HF pump-induced artificial optical emissions
16 Feb 1999 4.04 MHz ERP = 75 MW O-mode
17:40 HF on17:40 HF on
17:44 HF off17:44 HF off
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HEATER HEATER and and UHF UHF
beam beam swinginswingin
ggUHF zenith angle
7 Oct 1999
4.954 MHz
ERP = 100 MW
O-mode
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ARTIFICIAL AURORAARTIFICIAL AURORA shifted onto magnetic field line
21 Feb 199921 Feb 1999630 nm 630 nm Start time:Start time:17.07.50 UT 17.07.50 UT Step=480 secStep=480 sec4.04 MHzERP = 75 MWO-mode
Heater beam(vertical)
Spitze direction
Field aligned
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SEESEE
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are weak radio waves produced in the ionosphere by HF pumping. They were originally discovered at HEATING.
Stimulated Electromagnetic Stimulated Electromagnetic EmissionsEmissions
HF transmit frequency
Gyroharmonic 1.38 MHz in F-layer
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Special effects appear for HF frequencies close to an electron gyro-harmonic.
(~1.38 MHz in F-layer)
GYRO-GYRO-HARMONICHARMONIC
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GYROHARMONIGYROHARMONICC
Artificial aurora 630 nm
Cutlass
UHF
3 Nov 2000 ERP = 70 MW O-mode
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Artificial HF modulation of Polar Mesospheric Summer Echoes. VHF backscatter power reduces by >40 dB.
10 July 1999
5.423 MHzERP = 630 MWX-mode
HF off
HF on
VHF PMSEPMSE
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Satellite in the magnetosphere
Heating Tx:0.2-1 GW HF waveis amplitude modulated and radiated
VLF receiver
0.001-1 W ULF/ELF/VLF wavesare radiated from the ionosphere
100 km altitude
30 km diameter
DC current Ionosphere
superimposedac current
Conductivity modulation causes electrojet modulation, which acts
as a huge natural antenna
ULF ELF VLF ULF ELF VLF waveswaves
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Very Low Frequency waves Very Low Frequency waves (kHz)(kHz)Natural (lightning) and artificial (HEATING) ducted VLF
waves resonate with trapped particles in the magnetosphere causing pitch angle scattering and precipitation.
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Ultra Low Frequency waves (3 Ultra Low Frequency waves (3 Hz)Hz)Field line tagging
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Artificial Artificial Periodic Periodic
Irregularities Irregularities (API)(API)The API technique was
discovered at SURA and allows any HF pump and ionosonde to probe the ionosphere. API are formed by a standing wave due to interference between the upward radiated wave and its own reflection from the ionosphere.
Measured parameters include: N(n), N(e), N(O-), vertical V(i), T(n), T(i) & T(e)
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Further informationFurther information
EISCAT/HEATING www.eiscat.uit.no/heater.htmlHAARP www.haarp.alaska.eduHIPAS www.hipas.alaska.eduARECIBO www.naic.eduSURA www.nirfi.sci-nnov.ru/english/index2e.htmlSPEAR www.ion.le.ac.uk/spear/