Comparison of different methods of VLF/ELF/ULF radio waves generationD.S. Kotik & S.V. Polaykov
1. Modulation of ionospheric currents by powerful RF radiation
Firstly detected VLF signal
Summary of Tromsǿ results
Typical experimental scheme
1eH
em
Mostly effective for generation at lover VLF (1-10 kHz)
Main restrictions: 1. at altitudes > 80 km
2. Sporadic character of electrojet events
2. Moving ionospheric source.
h~80km
x
H1 H2 d1=100(200)m
e -iωte –i (ωt+/-Ώ)t
(+)(-)
op1 op2R1=30km R2=300km
;
)cos(2021
kd
hV
h
dkXtEEEJ
ph
nonlinear
)12(6/2 kHzkhzhfdF
)12(6/2 kHzkhzhfdF
3. VLF Production by HF Heating Using the Thermal Cubic Nonlinearity
h~80km
H1 H2d1=100m
e -iωte –i (2ωt+/-Ώ)t
op1 R1=30km
Nonlinear nonresomance current:
The magnification factor is -- 2
22
H
1
0
E
E
j
j eH
cubic
thermal
Comparison with electrojet modulation method gives by ratio
01.19.1990f1=4.63 MHzP1=250 kWf2=9.05 MHzP2 =500 kW X polarization O polarization
em
4. ELF generation using 1 MWt broadcasting stations.
N. Novgorod
S. Petersburg
Lovo.
R=1300km
● Moscow
An example of correlation of signal amplitude received at NN with magnetic field variations on the Apatity for case KP-5+
The case of week disturbance (KP=20)
)exp(2
4
2
kh
MkН
kWPP radW2002.0~
To Barentsburg, 1200km
5. ULF generation using power lines
Sodankyla data (distance 500 km)HE-W component.
AverageULF spectrum for HN-S
Hautavaara, 00:03-03:00 LT, 28.09.01.
Lovozero
Geometry of the experiment
δ
CONTROLLER
Matchingcapacitors
ULF generator-converter
R
Precisiongenerator
power~380V50Hz
Power line 108 km longPower plant
~380kV
Consumers
5. EXPERIMENTAL INSTALLATIONS
.02
For F = 10 Hz δ ~ 6-8 km
1.0E-09
1.0E-08
1.0E-07
1.0E-06
1.0E-05
1.0E-04
0 500 1000 1500 2000 2500 3000 3500 4000
0 45 90 Hi,SURA(800) Hi,TRMSO(800)
7. CONCLUSIONS
Magnetic field distance dependence for Kola ground based ULF facility (for three azimuth
directions) and for SURA and Tromso ionospheric ULF
antennas at 40 Hz radiated frequency.
BAND
METHOD APPLIANCEFIELDS
Low VLF1 –10 kHz
Direct modulation of ionospheric currents by RF heaters
Diagnostic of low Ionosphere, studying of propagation in E-I waveguide
High VLF 10 –20 kHz
1. Moving source, 2. Thermal cubic nonlinearity. Both using heaters with complicate arrays
Diagnostic of low Ionosphere, studying of E-I waveguide,injection intomagnetosphere
ELF0.1 – 1 kHz
Direct modulation of ionospheric currents by powerful broadcasting stations
Diagnostic of low Ionosphere, studying of E-I waveguide,Earth exploration for geoengineering
ULFbelow 100Hz
Long power lines with ULF generator
Diagnostic of low Ionosphere, studying of E-I waveguide,Deep Earth exploration Studying of nearEarth ULF resonators injection intomagnetosphere
The estimated and experimentally confirmed zone of assured ULF signal detection for ULFRAD.
3.5 4 4.5 5 5.52
4
6
8
10
12
14
McIlwain parameter, L
pro
ton g
yro
frequency,
Hz
The ULFRAD concept