Venus: measurements of microwave brightness temperatures and interpretations of the radio and radar spectra

Warnock, William W.

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https://hdl.handle.net/2142/79024 Copy

Description

Title

Venus: measurements of microwave brightness temperatures and interpretations of the radio and radar spectra

Author(s)

Warnock, William W.

Issue Date

1971-09

Director of Research (if dissertation) or Advisor (if thesis)

Dickel, John R.

Department of Study

Astronomy

Discipline

Astronomy

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D. (doctoral)

Degree Level

Dissertation

Keyword(s)

• Venus
• Microwave radiation
• Radio Astronomy
• Radar spectra

Language

en

Abstract

Fifteen years ago passive microwave radiation from Venus was first measured (Mayer, et al., 1958). Nearly one hundred sets of radio observations have now been published, for wavelengths ranging from 0.1 to 70 cm. For these wavelengths, Planck's radiation law can be replaced by the Rayleigh-Jeans approximation, in which the brightness of the source is proportional to the first power of its blackbody temperature. For observations made with a single radio telescope, no significant resolution over the disk of Venus is possible. In the reductions of such observations, the planet is assumed to radiate uniformly over its disk. The measured flux density is then proportional to the diskaveraged brightness temperature, defined as the temperature of a perfect radiator subtending the same solid angle as Venus and emitting the same flux density of radiation at the wavelength of observation. The disk-averaged brightness temperature is often called simply the brightness temperature, and its variation with wavelength defines the radio spectrum of the planet.

Type of Resource

text

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http://hdl.handle.net/2142/79024

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