Measurement of decimeter-wave absorption in the atmosphere

Krotikov, V. D.; Lastochkin, V. P.; Stankevich, K. S.

doi:10.1007/bf01038842

Cited by 2 publications

(4 citation statements)

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“…4 for the wavelength range 0.1 to 100 cm. Also plotted in red squares is a more recent assessment of the data (Krotikov & Pelyushenko 1987). The paper by Zhang et al (2012) summarizes modern observations which show a mean brightness at 1.4 GHz (λ ≈21 cm) of 233±2 K. This indicates that the mean temperature at a depth of ≈ 2 m is 20 to 30 K higher than in the thin surface layer responsible for the emission at sub-millimetre wavelengths (Fig.…”

Section: The Mean Brightness Temperature At Radio Frequenciesmentioning

confidence: 93%

“…Table 2. Brightness temperature of the Moon at selected frequencies; the data are from Krotikov & Pelyushenko (1987). Listed are the mean brightness temperatures over a lunation, T 0 , the amplitude of the 29.3-day first harmonic, T 1 , and the phase shift of this harmonic as measured from the time of New Moon, ξ.…”

Section: The Diameter Of the Quiet And Active Sun As A Function Of Frmentioning

confidence: 99%

“…The source of the data is as for Fig. 4 with a best-fit model (Krotikov & Pelyushenko 1987) indicated by red squares. It is seen that the variation is greatest (≈ 100 K) at high frequencies where the emission comes from a thin surface layer.…”

Section: The Mean Brightness Temperature At Radio Frequenciesmentioning

confidence: 99%

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A radio determination of the time of the New Moon

Hafez

Trojan

Albaqami

et al. 2014

Monthly Notices of the Royal Astronomical Society

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The detection of the New Moon at sunset is of importance to communities based on the lunar calendar. This is traditionally undertaken with visual observations. We propose a radio method which allows a higher visibility of the Moon relative to the Sun and consequently gives us the ability to detect the Moon much closer to the Sun than is the case of visual observation. We first compare the relative brightness of the Moon and Sun over a range of possible frequencies and find the range 5-100 GHz to be suitable. The next consideration is the atmospheric absorption/emission due to water vapour and oxygen as a function of frequency. This is particularly important since the relevant observations are near the horizon. We show that a frequency of ∼ 10 GHz is optimal for this programme. We have designed and constructed a telescope with a FWHM resolution of 0 • .6 and low sidelobes to demonstrate the potential of this approach. At the time of the 21 May 2012 New Moon the Sun/Moon brightness temperature ratio was 72.7 ± 2.2 in agreement with predictions from the literature when combined with the observed sunspot numbers for the day. The Moon would have been readily detectable at ∼ 2 • from the Sun. Our observations at 16 hr 36 min UT indicated that the Moon would have been at closest approach to the Sun 16 hr 25 min earlier; this was the annular solar eclipse of 00 hr 00 min UT on 21 May 2012.

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Section: The Mean Brightness Temperature At Radio Frequenciesmentioning

confidence: 93%

Section: The Diameter Of the Quiet And Active Sun As A Function Of Frmentioning

confidence: 99%

See 1 more Smart Citation

A radio determination of the time of the New Moon

Hafez

Trojan

Albaqami

et al. 2014

Monthly Notices of the Royal Astronomical Society

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“…Also, at frequencies below 2 Ghz the results are somewhat higher than expected, and several of the authors concerned with these measurements have considered that there is a significant difference between their experimental results and the theoretically derived values. Perhaps prompted by this apparent discrepancy, Lastochkin and Stankevich [1963] have criticized Van Vleck's formula, and a further theoretical treatment of nonresonance oxygen absorption has recently been given [Stankevich, 1965]. However, at frequencies above 2 Ghz, somewhat lower values of attenuation have been obtained, and most of the measurements closely approximate the solid curve shown in the figure.…”

Section: Introductionmentioning

confidence: 99%

Total atmospheric attenuation at 3.2 gigahertz

Medd¹,

Fort²

1966

J. Geophys. Res.

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Total atmospheric attenuation has been measured at 3.2 Ghz, where the attenuation is due primarily to nonresonance absorption of molecular oxygen. The experimental techniques of radio astronomy were used to obtain effective antenna temperatures for discrete sources at various angles of elevation. The result for vertical incidence is 0.042 db. An examination of the possible sources of error indicates that an appreciable systematic error is improbable; the accuracy of the experiment is estimated as +--0.004 db probable error.

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Measurement of decimeter-wave absorption in the atmosphere

Cited by 2 publications

References 0 publications

A radio determination of the time of the New Moon

A radio determination of the time of the New Moon

Total atmospheric attenuation at 3.2 gigahertz

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