Solar noise observations from the Alouette satellite

Solar radio noise in the frequency range 1.5 to 10 MHz appears sporadically in the Alouette sweep-frequency recordings above the galactic noise level. The type III bursts can be readily identified, but other spectral types are much more difficult to identify from only the satellite records. Using a plausible model for the coronal electron densities, the Type III frequency drift curves have been interpreted as corresponding to a source velocity in the range 0.1 to 0.15 times the velocity of light. Preliminary estimates have also been made of the coronal temperatures from some of the burst durations.Other solar noise events of longer duration have not been classified other than as enhanced solar noise at this stage. These enhancements frequently show an intensity structure, extending down to the 1.5 MHz lower frequency limit of the equipment. These events are discussed briefly.

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Coincident bursts of auroral kilometric radiation and VLF emissions associated with a type III solar radio noise event

Journal of Geophysical Research Atmospheres ◽

10.1029/94ja02757 ◽

1995 ◽

Vol 100 (A1) ◽

pp. 281

Author(s):

T. J. Rosenberg ◽

S. Singh ◽

C. S. Wu ◽

J. LaBelle ◽

R. A. Treumann ◽

...

Keyword(s):

Solar Radio ◽

Radio Noise ◽

Type Iii ◽

Auroral Kilometric Radiation ◽

Vlf Emissions

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The correlation of solar radio bursts by magnetic activity and cosmic rays

Symposium - International Astronomical Union ◽

10.1017/s0074180900050853 ◽

1959 ◽

Vol 9 ◽

pp. 210-213

Author(s):

A. R. Thompson

Keyword(s):

Cosmic Rays ◽

Radio Astronomy ◽

Solar Radio ◽

Magnetic Activity ◽

Radio Bursts ◽

Type Ii ◽

Frequency Range ◽

Sweep Frequency ◽

Solar Radio Bursts ◽

Auroral Particles

The sweep-frequency equipment at the Harvard Radio Astronomy Station, Fort Davis, Texas, has now been running continuously since 1956 September, recording solar radio activity in the frequency range from 100 to 580 Mc/s. The following contribution describes preliminary investigations of the correlation of the radio data with solar corpuscular emissions. This work was initiated to examine the well-known suggestions that the origins of the type II and type III radio bursts are associated with the ejection of auroral particles and cosmic rays respectively.

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Type III solar radio noise bursts at hectometer wavelengths

Planetary and Space Science ◽

10.1016/0032-0633(69)90044-0 ◽

1969 ◽

Vol 17 (2) ◽

pp. 267-287 ◽

Cited By ~ 50

Author(s):

T.R. Hartz

Keyword(s):

Solar Radio ◽

Radio Noise ◽

Type Iii

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Vibrational Circular Dichroism Measurement in the Frequency Range of 800 to 650 cm−1

Applied Spectroscopy ◽

10.1366/0003702874447581 ◽

1987 ◽

Vol 41 (7) ◽

pp. 1142-1144 ◽

Cited By ~ 27

Author(s):

F. Devlin ◽

P. J. Stephens

Keyword(s):

Fourier Transform ◽

Circular Dichroism ◽

Vibrational Circular Dichroism ◽

Fourier Transform Spectrometer ◽

Instrumental Performance ◽

Frequency Range ◽

Frequency Limit ◽

Circular Dichroism Measurement ◽

Circular Dichroïsm ◽

Lower Frequency Limit

The development of dispersive instrumentation for the measurement of vibrational circular dichroism (VCD) with a lower frequency limit of ∼650 cm−1 is reported. VCD spectra of 3-methylcyclohexanone, α-pinene, and 3-bromocamphor in the frequency range of 800 to 650 cm−1 are presented to illustrate instrumental performance. The spectra obtained are superior to earlier spectra obtained with the use of a Fourier transform spectrometer.

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Spectral Analysis of Solar Radio Type III Bursts from 20 kHz to 410 MHz

The Astrophysical Journal ◽

10.3847/1538-4357/ac34ed ◽

2022 ◽

Vol 924 (2) ◽

pp. 58

Author(s):

K. Sasikumar Raja ◽

Milan Maksimovic ◽

Eduard P. Kontar ◽

Xavier Bonnin ◽

Philippe Zarka ◽

...

Keyword(s):

Solar Radio ◽

Spectral Response ◽

Wind Waves ◽

Wide Frequency Range ◽

Radio Flux ◽

Frequency Range ◽

Data Set ◽

Type Iii ◽

Spectral Profiles ◽

First Time

Abstract We present the statistical analysis of the spectral response of solar radio type III bursts over the wide frequency range between 20 kHz and 410 MHz. For this purpose, we have used observations that were carried out using both spaced-based (Wind/Waves) and ground-based (Nançay Decameter Array and Nançay Radioheliograph) facilities. In order to compare the flux densities observed by the different instruments, we have carefully calibrated the data and displayed them in solar flux units. The main result of our study is that type III bursts, in the metric to hectometric wavelength range, statistically exhibit a clear maximum of their median radio flux density around 2 MHz. Although this result was already reported by inspecting the spectral profiles of type III bursts in the frequency range 20 kHz–20 MHz, our study extends such analysis for the first time to metric radio frequencies (i.e., from 20 kHz to 410 MHz) and confirms the maximum spectral response around 2 MHz. In addition, using a simple empirical model we show that the median radio flux S of the studied data set obeys the polynomial form Y = 0.04X 3 − 1.63X 2 + 16.30X − 41.24, with X = ln ( F MHz ) and with Y = ln ( S SFU ) . Using the Sittler and Guhathakurtha model for coronal streamers, we have found that the maximum of radio power therefore falls in the range 4 to 10 R ⊙, depending on whether the type III emissions are assumed to be at the fundamental or the harmonic.

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Evaluation of Special Hearing Aids for Deaf Children

Journal of Speech and Hearing Disorders ◽

10.1044/jshd.3604.527 ◽

1971 ◽

Vol 36 (4) ◽

pp. 527-537 ◽

Cited By ~ 1

Author(s):

Norman P. Erber

Keyword(s):

Hearing Aids ◽

High Frequency ◽

Hearing Aid ◽

Low Frequency ◽

Acoustic Stimulation ◽

Deaf Children ◽

Frequency Range ◽

Frequency Limit ◽

Unpublished Studies ◽

Published Research

Two types of special hearing aid have been developed recently to improve the reception of speech by profoundly deaf children. In a different way, each special system provides greater low-frequency acoustic stimulation to deaf ears than does a conventional hearing aid. One of the devices extends the low-frequency limit of amplification; the other shifts high-frequency energy to a lower frequency range. In general, previous evaluations of these special hearing aids have obtained inconsistent or inconclusive results. This paper reviews most of the published research on the use of special hearing aids by deaf children, summarizes several unpublished studies, and suggests a set of guidelines for future evaluations of special and conventional amplification systems.

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