The spectrum of background low-frequency radio emission

Krymkin, V. V.

doi:10.1007/bf01031395

Cited by 18 publications

(8 citation statements)

References 3 publications

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“…It should be recalled also that in the UTR-2 frequency range the system noise temperature is produced basically by Galactic background radiation. The noise temperature is about 28 300 K at 25 MHz (Krymkin 1971), and higher at lower frequency.…”

Section: Digital Receiver For Radio Astronomy Applicationsmentioning

confidence: 95%

Frequency drift rate of solar decameter “drift pair” bursts

Stanislavsky

Konovalenko

Volvach

2017

Res. Astron. Astrophys.

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This paper deals with the detailed analysis of frequency drift rates of solar "drift pair" (DP) bursts observed from 2015 July 10 to 12 during a type III burst storm. The observations were conducted by the UTR-2 radio telescope at 9-33 MHz with high frequency and time resolution. DPs were recorded drifting from higher to lower frequencies (forward DPs) as well as from lower to higher ones (reverse DPs). Patterns on their dynamic spectrum had various inclines and occupied different bandwidths. The frequency drift rate versus frequency dependence of these bursts has been studied. The fitting model to describe the peak evolution of these bursts in the frequency-time plane is presented. The relationship between DPs and type III solar bursts is discussed.

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Section: Digital Receiver For Radio Astronomy Applicationsmentioning

confidence: 95%

Frequency drift rate of solar decameter “drift pair” bursts

Stanislavsky

Konovalenko

Volvach

2017

Res. Astron. Astrophys.

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“…The dependences Z d (ν) and Z pre (ν), which were used in the calculations, were experimentally obtained. They are [13]). It is seen that the peak-to-peak value of T a sky (ν) is equal to 7 dB.…”

Section: Preamplifiermentioning

confidence: 94%

“…It is known that the ratio γ of maximum to minimum temperature T a sky takes a maximum value for an "ideal" active dipole that has a noiseless amplifier and is placed over a perfectly conducting ground. Krymkin [13] carried out experiments at the UTR-2 observatory to estimate the ratio γ for the "real" half-wave dipole which had a low noise amplifier and was placed over a large ground screen. It was found that γ max ranges from 2.4 to 3.0 dB over the frequency range of interest.…”

Section: Fig 14 Preamplifier Noise Measurement Systemmentioning

confidence: 99%

Wide-band high linearity active dipole for low frequency radio astronomy

et al. 2011

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We have developed an active dipole that is intended for use in new generation low frequency array applications. The preamplifier of the active dipole has very high linearity (input IP2 = 70 dBm, input IP3 = 31 dBm) and low noise temperature (100-360 K). The frequency dependence of the dipole impedance and the match between the dipole and preamplifier have been optimized to achieve Galactic noise limited operation. The ratio between the antenna temperature due to Galactic noise and the noise temperature of the preamplifier is 10 ± 1.5 dB over the whole 10 to 70 MHz range. The total cost of the active cross-dipole is 220 euro.

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“…At the lower frequencies (42 MHz and 25 MHz), the ratio γ also remains high enough (2.4 dB and 1.9 dB, correspondingly). Furthermore, as the maximum of T a sky was obtained in the daytime, when the absorption in the ionosphere is rather strong, it can be shown by a simple calculation [Krymkin, 1971] that these values were underestimated by 0.15 dB and 0.3 dB at 42 MHz and 25 MHz, respectively. Figure 3 displays the sample dynamic spectrum of the type III solar radio-burst as obtained by a digital spectral processor at the dipole output.…”

Section: The Active Dipole For the Low-frequency Arraymentioning

confidence: 95%

“…It is known that the γ is the ratio of maximum to minimum temperature T a sky and takes a maximum value for an "ideal" active dipole that has a noiseless amplifier and is placed over a perfectly conducting ground. Krymkin [1971] carried out experiments at the UTR-2 observatory to estimate the ratio γ for the "real" half-wave dipole which had a low noise amplifier and was placed over a large ground screen. Krymkin found that γ max (maximum meaning of γ) ranges from 2.4 to 3.0 dB over the frequency range of interest.…”

Section: The Active Dipole For the Low-frequency Arraymentioning

confidence: 99%

Tests of an Active, Broad-band Antenna Array

Bubnov¹,

Konovalenko²,

Falkovich³

et al. 2011

Planetary Radio Emissions Vii

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In this paper, test results from a 25-element active antenna prototype array operating in the frequency range of 10-70 MHz are presented. Observations of radio emission from different sources: solar sporadic radio emission and powerful cosmic radio sources including their ionosphere scintillation, demonstrate the high effectiveness of the system due to the Galactic background limited sensitivity and high dynamic range of the antenna amplifier (noise immunity). This demonstrates the capability of this 25-element active antenna array to engage in a wide range of unique wide band radio astronomical observations of solar system objects that do not require high sensitivity and angular resolution.

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The spectrum of background low-frequency radio emission

Cited by 18 publications

References 3 publications

Frequency drift rate of solar decameter “drift pair” bursts

Frequency drift rate of solar decameter “drift pair” bursts

Wide-band high linearity active dipole for low frequency radio astronomy

Tests of an Active, Broad-band Antenna Array

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