Begell House Inc.
Radio Physics and Radio Astronomy
RPRA
2152-274X
1
3
2010
DECAMETRIC SOLAR U- AND J-TYPE BURSTS
181-188
10.1615/RadioPhysicsRadioAstronomy.v1.i3.10
V. V.
Dorovsky
Institute of Radio Astronomy, National Academy of Sciences of Ukraine
V. N.
Melnik
Institute of Radio Astronomy, National Academy of Sciences of Ukraine
Alexandr A.
Konovalenko
Institute of Radio Astronomy of the National Academy of Sciences of Ukraine
H. O.
Rucker
Institut für Weltraumforschung der Österreichischen Akademie der Wissenschaften, 6, Schmiedlstrasse, Graz, 8042, Austria
E. P.
Abranin
Institute of Radio Astronomy, National Academy of Sciences of Ukraine
A.
Lecacheux
Ovservatoire Paris-Meudon, Paris, CNRS UMR 8644, France
radiotelescope
decameter waveband
solar bursts
coronal plasma
The first solar decameter wavelength U- and J-bursts observed with the UTR-2 radiotelescope in 2003-2004 are
reported. During that period, more than 50 J-bursts and only 7 U-bursts had been recorded. It is the first case
of the J- and U-bursts ground-observed with the turning frequencies ranging between 10 and 25 MHz. A harmonic
structure of J-bursts in the form of Jb-J pairs similar to well known type IIIb-III pairs was first found. The average
ratio of harmonic frequencies appeared to be 1.8. A group of J-bursts was recorded with an unusual Turning
Frequency Drift (TFD) of –2 kHz/s. Such a TFD corresponds to the coronal loop elevation velocity of about 60 km/s. Coronal loops with similar elevation velocities were also detected with the SOHO/LASCO coronagraph in visible light. The dynamic spectra of unusual U- and J-bursts are shown. A simplified model of a semicircle-shaped coronal loop was constructed on basis of the U-burst dynamic spectrum and the Newkirk coronal density model. With this loop model, the source linear traverse speed along the loop, height of the turning frequency point and loop geometry were calculated.
OZONOSPHERE AS A SHIELD OF THE TROPOSPHERE-TO-IONOSPHERE ENERGY TRANSFER
189-196
10.1615/RadioPhysicsRadioAstronomy.v1.i3.20
A. V.
Zalizovskiy
Institute of Radio Astronomy, National Academy of Sciences of Ukraine, 4, Chervonopraporna St., Kharkiv, 61002
ozonosphere
troposphere
mesosphere
ionospheric scattering
energy exchange
temperature gradient
The impact of the ozone layer over the Antarctic Peninsula on the statistical correlation between the tropospheric
weather and ionospheric spread-F phenomenon is investigated. The data obtained at the Akademik Vernadsky Station from 1995 through 2004 on the days of the ozone hole development (from 11 September till 5 October) are used. It has been found that under low ozone conditions (less than 180 D. U.) the conditional probability of the spread-F appearance is greater in the presence of atmospheric fronts than when they are absent. Under high ozone conditions (more than 180 D. U.), statistical relationship between the frontal activity
and spread-F phenomenon disappears, i. e. the ozone layer becomes a kind of a shield for the troposphere-toionosphere
energy transfer. Apparently, a reason for this is increasing of the stratospheric temperature and vertical temperature gradients of the middle atmosphere at higher ozone amount, which effect makes poorer conditions for atmospheric gravity wave propagation.
STATISTICS OF DOPPLER SPECTRA OF RADIO SIGNALS REFLECTED FROM A NATURALLY DISTURBED IONOSPHERE
197-209
10.1615/RadioPhysicsRadioAstronomy.v1.i3.30
S. V.
Panasenko
V. Karazin National University of Kharkiv
L. F.
Chernogor
V. Karazin National University of Kharkov, 4, Svoboda Sq., Kharkov, 61077; A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine, 12, Academician Proskura St., Kharkov 61085, Ukraine
radio signal
Doppler spectrum
ionosphere
spectral analysis
quasiperiodic and quasiregular
processes
Results of statistical analysis of time variations of Doppler spectra of vertically propagating radio signals are shown. An HF Doppler radar was used for ionospheric sounding. Doppler spectra are analyzed for the day of a solar eclipse occurred on August 1, 2008 and for days characterized by background ionospheric conditions. Statistics of the Doppler spectra and parameters of the turbulent ionosphere are estimated. The solar eclipse is shown to produce considerable perturbations in the ionosphere.
ELF-BAND RECEIVER MEASURING COMPLEX WITH VHF RETRANSMITTER
211-220
10.1615/RadioPhysicsRadioAstronomy.v1.i3.40
V. E.
Paznukhov
Institute of Radio Astronomy, National Academy of Sciences of Ukraine
O. V.
Budanov
Institute of Radio Astronomy, National Academy of Sciences of Ukraine 4, Mystetstv St., Kharkov, 61002, Ukraine
A. G.
Rokhman
Institute of Radio Astronomy, National Academy of Sciences of Ukraine
Y. V.
Aristov
Institute of Radio Astronomy, National Academy of Sciences of Ukraine
ELF band
Antarctic Station
monitoring
receiver measuring complex
spectral
polarization
The receiving point created in Martove, Kharkiv region at Institute of Radio Astronomy NASU’s Low-Frequency
Observatory intended for monitoring the Earth’s ELF electromagnetic environment is described. Basic trends
in the ELF-band research and the receiver-measuring equipment required are discussed. The complex location
area and its structure are substantiated with the account for local interferences characteristic of the ELF band.
Its block diagram is shown too, separate units briefly described. Experimental data are compared with those
obtained at the Akademik Vernadsky Ukrainian Antarctic Station. Simultaneous processing of synchronous
data from the two remote stations, e.g. locating lightning strokes, is shown possible.
TRAPPED-MODE RESONANCES IN LIGHT DIFFRACTION BY A PLANAR DOUBLY PERIODIC STRUCTURE WITH ASYMMETRIC METAL ELEMENTS
221-231
10.1615/RadioPhysicsRadioAstronomy.v1.i3.50
V. V.
Khardikov
V. Karazin National University of Kharkov, Institute of Radio Astronomy, National Academy of Sciences of Ukraine, Kharkov, Ukraine
E. O.
Iarko
Institute of Radio Astronomy, National Academy of Sciences of Ukraine
S. L.
Prosvirnin
V. Karazin National University of Kharkov; Institute of Radio Astronomy, National Academy of Sciences of Ukraine
light diffraction
doubly periodic planar structure
trapped-mode resonance
pseudospectral time domain method
The diffraction of a plane wave normally incident on a planar periodic structure with a square periodic cell
of two slightly asymmetric complex-shaped metal elements has been numerically solved for the optical and
infrared regions. The solution is due to the mapped pseudospectral Fourier method combined with the auxiliary
differential equation technique and the pole model for describing the metal permittivity dispersion. It has been
found that the structure can form a trapped-mode resonance outperforming in Q the plasmon-polariton resonances
in structures with single metal element cells. It has been first shown that the high-order trapped-mode
resonance can outperform in Q the corresponding fundamental trapped-mode resonance.
A FINITE CONDUCTING CONE IN RADIATION FIELD OF A RING SOURCE
233-240
10.1615/RadioPhysicsRadioAstronomy.v1.i3.60
O. B.
Trishchuk
Karpenko Physico-Mechanical Institute, National Academy of Sciences of Ukraine
D. B.
Kuryliak
G.V. Karpenko Physical-Mechanical Institute, National Academy of Sciences of Ukraine 5, Naukova St., L'viv 79060, Ukraine
radiation resistance
polarization
oscillation
semi-inversion technique
radiation pattern
The diffraction properties of the field produced by a ring-shaped current source placed above a finite-extension
cone are discussed. Dependences have been established between the radiation power and the electrodynamical
system geometrical parameters in the H- and E-polarization cases. Radiation patterns at extreme values of the
normalized radiation power of the diffraction system are reported. A comparison with the semi-infinite cone
results is available.
DIFFRACTION OF 3-D GAUSSIAN BEAM WITH CIRCULAR SYMMETRY OF THE FIELD SPACE DISTRIBUTION ON PERMEABLE SCREENS AT SMALL ANGLES OF INCIDENCE
241-247
10.1615/RadioPhysicsRadioAstronomy.v1.i3.70
V. V.
Yachin
Institute of Radio Astronomy, National Academy of Sciences of Ukraine, 4, Chervonopraporna St., Kharkiv, 61002, Ukraine
T. L.
Zinenko
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine 12, Academician Proskura St., Kharkov 61085, Ukraine
V. K.
Kiseliov
A. Usikov Institute of Radio Physics and Electronics, National Academy of Sciences of Ukraine; V.N.Karazin Kharkiv National University 4, Svobody sq., 61022, Kharkiv, Ukraine
S. N.
Vorobyov
Institute of Radio Astronomy, National Academy of Sciences of Ukraine 4, Mystetstv St., Kharkiv 61002, Ukraine
Gaussian beam
diffraction
spatial spectrum
field distribution
magnetodielectric structure
Scattering of a 3-D Gaussian beam incident at a small angle onto a double-periodic magnetodielectric slab has
been formulated and solved. The new formulas for incident and scattered 3-D Gaussian beam fields have been
derived in the form of single integrals. These allow reducing the time spent upon numerical calculations of the
incident and scattered beam fields and improving their accuracy. The calculations of the 3-D Gaussian beam
obliquely incident onto magnetodielectric slab with the derived formulas are illustrated.
IMPROVEMENT OF EXTRAPOLATION-BASED MICROWAVE RANGE FOURIER HOLOGRAPHY METHOD EMPLOYING A MINIMUM-DURATION METHOD
249-256
10.1615/RadioPhysicsRadioAstronomy.v1.i3.80
O. S.
Antropov
O.Gonchar Dnepropetrovsk National University, Ukraine
V. F.
Borulko
Oles Honchar Dnipro National University, 72, Gagarin Ave., Dnipro, 49010, Ukraine
S. M.
Vovk
Oles Honchar Dnipropetrovsk National university 72, Gagarin Avenue, Dnipropetrovsk, 49051, Ukraine
O. O.
Drobakhin
Oles Honchar Dnipro National University, 72, Gagarin Ave., Dnipro, 49010, Ukraine
Fourier holography
radio signal
reflectivity
reflectometer
spectral analysis
Modification of the Fourier holography method is proposed for restoration of complex multifrequency reflection
coefficient data of layered dielectric structure, which consists in extrapolation of modulus square multifrequency
reflection coefficient data at the first step of data processing. Extrapolation is carried out on assumption
that the synthesized time domain signal support, this latter being minimized, is finite. Extrapolation in the frequency domain facilitates the choice of weighting function for extraction from reflection time-response of a time signal corresponding to a structure proper. A minimum-duration method is used for solution of extrapolation problem.
FIELD STATISTICS OF A CIRCULAR APERTURE ANTENNA
257-270
10.1615/RadioPhysicsRadioAstronomy.v1.i3.90
Ya. S.
Shifrin
Kharkov National University of Radio Engineering and Electronics, Ukraine
V. V.
Dolzhikov
Kharkov National University of Radio Engineering and Electronics, 14, Lenin Ave, Kharkov, 61166, Ukraine
aperture
phase fluctuations
correlation
statistical characteristics
dispersion
The field statistics of a circular aperture antenna focused to the Fresnel zone under phase fluctuations on its
aperture is considered. The basic relationships are formulated in the form being invariant with respect to the
focus point location. This allows using them when studying the field of both focused and unfocused ("ordinary")
antennas in their Fresnel and far zones. Formulas for the mean and fluctuation characteristics of the
field are given; plots illustrating these characteristics versus the fluctuations dispersion and correlation radius
are presented. The results obtained for the circular aperture are compared with those obtained earlier by the
authors for the linear antenna.