79. Radio emission from the moon and the nature of its surface

A theoretical study of the integral radio emission of the moon, measured at the wave-length of 3·2 cm. (Zelinskaja and Troitzky[1]; Kajdanovsky, Turusbekov and Khaikin[2]), was carried out at the Gorky radio astronomical station ‘Zimenky’ and at the Physical Institute of the Academy of Sciences of the U.S.S.R. The following expression for the average radio temperature of the entire lunar disk, as a function of the lunar phase, Ωt, was obtained (Troitzky, 1954) [3]: Here tan ξ = δ/(1 + δ) and δ = β/κ, where β is the attenuation coefficient of the thermal wave, κ the power attenuation coefficient of the radio wave. Further, Tm = 374°K. is the temperature of the subsolar point, Tn is the temperature at the lunar midnight, Θ = Tm – Tn and k0 is the reflexion coefficient of radio waves for vertical incidence (k0 ≈ 0–1). The numerical coefficients in equation (1) were obtained as a result of averaging the Fresnel reflexion coefficients over the whole disk. The degree of polarization of the total radio emission was calculated and was found to be about 4 %.

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46. The structure of the solar chromosphere from centimetre-wave radio observations

Symposium - International Astronomical Union ◽

10.1017/s0074180900049214 ◽

1957 ◽

Vol 4 ◽

pp. 263-268 ◽

Cited By ~ 2

Author(s):

J. P. Hagen

Keyword(s):

Wave Length ◽

Outer Part ◽

Wave Radiation ◽

Solar Chromosphere ◽

The Sun ◽

Radio Waves ◽

Visible Radiation ◽

Short Radio Wave ◽

Wave Radio ◽

Image Position

The atmosphere of the sun is transparent to visible radiation, is nearly transparent to millimetre and centimetre radio radiation, and becomes opaque to the metre and longer wave radiation. Information about the chromosphere can then be given by observing the radiation from the sun at short radio wave-lengths. In its outer part, the atmosphere of the sun is highly ionized. Absorption in any region is directly proportional to the square of the density and the wave-length squared and inversely to the temperature to the three-halves power This is the familiar equation for the absorption of radio waves in an ionized medium. By consequence of this, the longer wave radiation is absorbed in the outer layers of the sun's atmosphere and can escape only from these outer regions. The shorter wave-length radiation is absorbed very little in the outer part of the solar atmosphere where the density is quite low, and hence radiation from the chromosphere escapes as centimetre and millimetre radio waves. In fact, the principal radiation from the sun in the centimetre and millimetre region comes from the chromosphere.

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37. Galactic radio emission and the distribution of discrete sources: Introductory Lecture

Symposium - International Astronomical Union ◽

10.1017/s0074180900049123 ◽

1957 ◽

Vol 4 ◽

pp. 211-217

Author(s):

R. Hanbury Brown

Keyword(s):

Radio Emission ◽

Thermal Emission ◽

Wave Length ◽

Black Body ◽

Interstellar Gas ◽

Ionized Gas ◽

Introductory Lecture ◽

The Galaxy ◽

Image Position ◽

Galactic Radio

At wave-lengths greater than about 1 metre the majority of the radio emission which is observed from the Galaxy cannot be explained in terms of thermal emission from ionized interstellar gas. This conclusion is widely accepted and is based on observations of the equivalent temperature of the sky and the spectrum of the radiation. The spectrum at metre wave-lengths is of the general form: where TA is the equivalent black-body temperature of a region of sky and λ is the wave-length. The exponent n varies with direction but lies between about 2·5 and 2·8, and is thus significantly greater than the value of 2·0 which is the maximum to be expected for thermal emission from an ionized gas. Furthermore, the value of TA is about 1050K. at 15 metres and thus greatly exceeds the electron temperature expected in H 11 regions.At centimetre wave-lengths it is likely that the majority of the radiation observed originates in thermal emission from ionized gas; however, the present discussion is limited to a range of wave-lengths from about 1 to 10 metres where the ionized gas in the Galaxy is believed to be substantially transparent and where the origin of most of the radiation is believed to be non-thermal.

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Thermal Radio Emission of the Moon at a Wave Length of 10 cm

Symposium - International Astronomical Union ◽

10.1017/s0074180900178507 ◽

1962 ◽

Vol 14 ◽

pp. 497-499

Author(s):

V. N. Koshchenko ◽

A. D. Kuzmin ◽

A. E. Salomonovich

Keyword(s):

Surface Layer ◽

Radio Emission ◽

Thermal Radiation ◽

Wave Length ◽

The Moon ◽

Phase Dependence ◽

Radio Range ◽

Thermal Radio ◽

Thermal Radio Emission

The investigations of intensity and phase dependence of the thermal radiation of the Moon at various wave lengths of the radio-range are very important for clarifying the properties and structure of the Moon's surface layer.

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Thermal Radio Emission of the Moon and Certain Characteristics of its Surface Layer

Symposium - International Astronomical Union ◽

10.1017/s0074180900178490 ◽

1962 ◽

Vol 14 ◽

pp. 491-495 ◽

Cited By ~ 1

Author(s):

A. E. Salomonovich

Keyword(s):

Surface Layer ◽

Radio Emission ◽

Additional Data ◽

Optical Data ◽

The Moon ◽

Lunar Crust ◽

Physics Institute ◽

Thermal Radio Emission ◽

Academy Of Sciences ◽

Selection Of

In order to use the data on the radio emission of the Moon as a basis for conclusions regarding the characteristics of the surface layer of the lunar crust, additional data or assumptions about the properties of this layer are necessary. The use of high-resolution radio telescopes reduces to a certain extent the unavoidable arbitrariness in the selection of parameters. Observations with the 22-m radio telescope of the Physics Institute, Academy of Sciences, made it possible to evaluate certain characteristics of the surface layer without relying entirely on optical data.

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First Results from Observations of the Moon by Means of a Polarimeter

Symposium - International Astronomical Union ◽

10.1017/s0074180900178465 ◽

1962 ◽

Vol 14 ◽

pp. 463-467

Author(s):

V. P. Dzhapiashvili ◽

L. V. Ksanfomaliti

Keyword(s):

Observational Data ◽

Direct Measurement ◽

Polarization Plane ◽

Light Polarization ◽

Degree Of Polarization ◽

The Moon ◽

First Results ◽

Image Position ◽

Additional Reduction

Until recently, no instrument was available for a direct measurement of the degree of light polarization and of the angle determining the position of the polarization plane. The degree of polarization was calculated by formulafrom the measurements of the maximum Φmaxand minimum Φminlight fluxes through an analyzer. A laborious additional reduction of the observational data was necessary for obtaining the final characteristics of light polarization.

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New data on the solar supercorona

Symposium - International Astronomical Union ◽

10.1017/s0074180900051007 ◽

1959 ◽

Vol 9 ◽

pp. 275-281

Author(s):

V. V. Vitkevich

Keyword(s):

Radio Emission ◽

Solar Corona ◽

Crab Nebula ◽

New Method ◽

Radio Waves ◽

Pass Through ◽

Academy Of Sciences ◽

The Crab Nebula

1. This paper reports on the results of the investigation of the outermost regions of the solar corona (which for brevity I shall call the supercorona) that have been obtained during recent years.Seven years ago, in 1951, a new method of observation was published in Doklady of the Academy of Sciences of the U.S.S.R. The idea of the method, which at the present time is well known, is that the radio emission of the Crab nebula is received at the time when the source is covered by the solar corona. This original eclipse takes place yearly in the middle of June.By receiving the radio waves that pass through the solar corona regions, we can estimate the effects of attenuation, scattering and refraction and reach some conclusions about the structure of the supercorona.

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Automated Determination of the Position of Ships by Satellites

Journal of Navigation ◽

10.1017/s0373463300024528 ◽

1967 ◽

Vol 20 (03) ◽

pp. 281-285

Author(s):

H. C. Freiesleben

Keyword(s):

Celestial Body ◽

World Wide ◽

Artificial Satellites ◽

Radio Waves ◽

The Moon ◽

Position Determination ◽

The Earth ◽

Navigational Aids ◽

Automated Determination

It has recently been suggested that 24-hour satellites might be used as navigational aids. To what category of position determination aids should these be assigned ? Is a satellite of this kind as it were a landmark, because, at least in theory, it remains fixed over the same point on the Earth's surface, in which case it should be classified under land-based navigation aids ? Is it a celestial body, although only one tenth as far from the Earth as the Moon ? If so, it is an astronomical navigation aid. Or is it a radio aid ? After all, its use for position determination depends on radio waves. In this paper I shall favour this last view. For automation is most feasible when an object of observation can be manipulated. This is easiest with radio aids, but it is, of course, impossible with natural stars.At present artificial satellites have the advantage over all other radio aids of world-wide coverage.

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2. On the Rotation of the Plane of Polarization by Quartz, and its relation to Wave-Length

Proceedings of the Royal Society of Edinburgh ◽

10.1017/s0370164600048197 ◽

1882 ◽

Vol 11 ◽

pp. 815-818 ◽

Cited By ~ 1

Author(s):

W. Peddie

Keyword(s):

Wave Length ◽

Angular Rotation ◽

Light Rays ◽

Image Position ◽

Polarization Of Light

The angular rotation of the plane of polarization of light-rays in their passage through quartz is a function of the wave-length, and is roughly represented by the formulawhere A is a constant depending on the quartz. This formula is only approximate, however, and one object of the experiments described below was to ascertain how closely the rotation might be represented by three terms of the equation

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