Centre-to-Limb Variation of Solar Radio Emission
Joachim Köppen DF3GJ ... Kiel, Aug 2019
Some brief explanations
These data are extracted from the plots in the original papers of Waldmeier & Müller
(1950, Z.f.Astrophysik 27, 58 and 1948, Astron.Mitt.Zürich 155) and Smerd (1950,
Australian Journal of Scientific Research A Physical Sciences, 2, 34). In these plots the
profiles for wavelengths shorter than 10 cm (or 3 GHz) are very small and thus are very
difficult to read accurately, but the intensity appears to be constant right up to the
solar edge.
- The profiles may be displayed in one of several versions:
- with the original scaling: the '1' of the ordinate means a brightness temperature
of 1.4 106 K (Waldmeier & Müller) or 106 K (Smerd).
- normalized to the brightness temperature seen at the centre of the disc.
- Since Waldmeier & Müller computed the emission from the corona only,
a contribution from the chromosphere is added, assumed to be 10000 K ...
- ... and normalized to the disc centre.
- enter the desired ranges of the coordinates, and hit the 'enter' key.
- instead of the radial profile, one may also show a tophat profile, which is similar
to the optical image.
- the drift scan plot shows how the sun would be appear as seen with an antenna having
the specified half-power beam width.