Decametric survey of discrete sources in the Northern sky

Braude, S. Ya.; Megn, A. V.; Ryabov, B. P.; Sharykin, N. K.; Zhouck, I. N.

doi:10.1007/bf00637902

Cited by 106 publications

(43 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[7] The estimates at 25 MHz were obtained with the use of the large phased antenna of the decameter wavelength radio telescope UTR-2 (Kharkov, Ukraine) [Braude et al, 1978]. The fluxes at 38 and 178 MHz have been taken from Kraus [1967].…”

Section: Observability Of Discrete Cosmic Radiomentioning

confidence: 99%

Application of an imaging HF riometer for the observation of scintillations of discrete cosmic sources

et al. 2008

View full text Add to dashboard Cite

[1] Scintillations of discrete cosmic radio sources have been investigated theoretically and experimentally for radiation scattered from natural and artificial inhomogeneities in the auroral zone ionosphere. The observations were performed at a frequency of 38.2 MHz with the multibeam phased array antenna of the imaging riometer located at Poker Flat, Alaska. For quiet ionospheric conditions and weak scintillations, the spatial spectrum and transverse motion velocities of the Fresnel inhomogeneities have been recovered. A theoretically based approach has been developed to estimate the time coherence interval of the radiation for the case of saturated scintillations and strong ionospheric turbulence. Examples of scintillation records are analyzed for the case of scattering from artificial ionospheric irregularities induced by high-power HF radiation from the high-power auroral simulation (HIPAS) ionospheric modification facility. The effect of aspectsensitive scattering of the cosmic source radiation by artificial field-aligned small-scale irregularities has been predicted and detected. Prospects for routine observations of the effects of scintillations and aspect-sensitive scattering are discussed for special operation modes of the ionospheric modification facility.

show abstract

Section: Observability Of Discrete Cosmic Radiomentioning

confidence: 99%

Application of an imaging HF riometer for the observation of scintillations of discrete cosmic sources

et al. 2008

View full text Add to dashboard Cite

show abstract

“…The advantages of the receiver discussed here, especially the efficiency of simultaneous usage of two input-output channels for reducing the signal confusion and improving RFI immunity, can be most clearly illustrated with operation at the decameter radio telescope UTR-2 (Kharkov, Ukraine, Braude et al 1978) that allows us to exploit the full range of receiver capacities due to its multi-beam architecture. The UTR-2 telescope is a phased array of 2040 dipole antennas grouped into two rectangular branches, north-south (NS) and east-west (EW), positioned in the form of a letter T and oriented along the local meridian and parallel, respectively, at coordinates 36 • 56 E longitude and +49 • 38 latitude.…”

Section: Use Of the Receiver With Utr-2 Decameter Arraymentioning

confidence: 99%

“…Nevertheless, the range below 30 MHz (HF range according to ITU) is of particular interest to planetary studies within the Solar system, searches for planets around distant stars (exoplanets) corresponding to moderate (exo-)planetary magnetic fields similar to Jupiter's, pulsar studies allowing detailed analysis of propagation effects magnified at these low frequencies, solar physics, and recombination lines, among other topics (Braude et al 1978;Boishot et al 1980;Lecacheux et al 2004). Thus, it is important and timely to develop modern instrumentation at non-imaging radio telescopes dedicated to the HF band, where emphasis can be placed on very high time and frequency resolution spectral analysis, waveform correlation analyses, multibeam (ON/OFF) observations to help correcting for the effects of the ionosphere, and development of in-depth RFI mitigation methods with the final goal of weak source detection and analysis.…”

Section: Introductionmentioning

confidence: 99%

“…Such a system is described in this paper. In 2005−2008, the receiver was tested for a frequency bandwidth of 33 MHz at A&A 510, A16 (2010) -Power spectrum -Coherence (Cross-correlation spectrum) Digital frequency down conversion Optional the world's largest decameter radio telescope UTR-2 (Ukraine) (Braude et al 1978;Ryabov et al 2004a;Lecacheux et al 2004). A series of observations were performed that targeted strong as well as comparatively weak (or even yet undetected) sources of radio emission known to exist in the decameter waveband, such as Jupiter Hess et al 2009), Saturn (Griessmeier et al 2008), exoplanets (Zarka et al 2001;Ryabov et al 2004b;Weber et al 2007), radio pulsars, and the Sun (Briand et al 2008;Melnik et al 2008).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A low-noise, high-dynamic-range, digital receiver for radio astronomy applications: an efficient solution for observing radio-bursts from Jupiter, the Sun, pulsars, and other astrophysical plasmas below 30 MHz

Ryabov¹,

Vavriv

Zarka

et al. 2010

A&A

Self Cite

View full text Add to dashboard Cite

A new two-channel digital receiver that can be used for observing both stationary and sporadic radio sources in the decameter wave band is presented. Current implementation of the device operating at the sampling frequency of 66 MHz is described in detail, including the regimes of waveform capture, spectrogram analysis, and coherence analysis (cross covariance between the two inputs). Various issues pertaining to observational methods in the decameter waveband affected significantly by man-made interferences have been taken into account in the receiver design, as well as in the architecture of the interactive software that controls the receiver parameters in real time. Two examples of using the receiver with the UTR-2 array (Ukraine) are reported: S-bursts from Jupiter and low-frequency wide-band single pulses from the pulsar PSR0809+74

show abstract

“…In this paper we attempt to redefine S burst classification based on new observations of several Jovian decametric radio storms recorded between 2004 and 2012 with the new generation of digital receivers (Ryabov et al 2010) installed at the Ukrainian UTR-2 decameter array (Braude et al 1978). The large, sensitive, electronically steerable UTR-2 array was combined with a baseband receiver allowing us to record high signalto-noise ratio waveforms of Jovian radio signals over a broad instantaneous bandwidth (∼16 MHz), during continuous time intervals lasting for several hours.…”

Section: Introductionmentioning

confidence: 99%

Fast and slow frequency-drifting millisecond bursts in Jovian decametric radio emissions

Ryabov

Zarka

Hess

et al. 2014

A&A

View full text Add to dashboard Cite

We present an analysis of several Jovian Io-related decametric radio storms recorded in 2004−2012 at the Ukrainian array UTR-2 using the new generation of baseband digital receivers. Continuous baseband sampling within sessions lasting for several hours enabled us to study the evolution of multiscale spectral patterns during the whole storm at varying time and frequency resolutions and trace the temporal transformation of burst structures in unprecedented detail. In addition to the well-known frequency drifting millisecond patterns known as S bursts we detected two other classes of events that often look like S bursts at low resolution but reveal a more complicated structure in high resolution dynamic spectra. The emissions of the first type (LS bursts, superposition of L and S type emissions) have a much lower frequency drift rate than the usual quasi linearly drifting S bursts (QS) and often occur within a frequency band where L emission is simultaneously present, suggesting that both LS and at least part of L emissions may come from the same source. The bursts of the second type (modulated S bursts called MS) are formed by a wideband frequency-modulated envelope that can mimic S bursts with very steep negative (or even positive) drift rates. Observed with insufficient time-frequency resolution, MS look like S bursts with complex shapes and varying drifts; MS patterns often occur in association with (i) narrowband emission; (ii) S burst trains; or (iii) sequences of fast drift shadow events. We propose a phenomenological description for various types of S emissions, that should include at least three components: high-and low-frequency limitation of the overall frequency band of the emission, fast frequency modulation of emission structures within this band, and emergence of elementary S burst substructures, that we call "forking" structures. All together, these three components can produce most of the observed spectral structures, including S bursts with apparently very complex time-frequency structures.

show abstract

Decametric survey of discrete sources in the Northern sky

Cited by 106 publications

References 20 publications

Application of an imaging HF riometer for the observation of scintillations of discrete cosmic sources

Application of an imaging HF riometer for the observation of scintillations of discrete cosmic sources

A low-noise, high-dynamic-range, digital receiver for radio astronomy applications: an efficient solution for observing radio-bursts from Jupiter, the Sun, pulsars, and other astrophysical plasmas below 30 MHz

Fast and slow frequency-drifting millisecond bursts in Jovian decametric radio emissions

Contact Info

Product

Resources

About