Balloon-borne imagery of the solar granulation. III - Digital analysis of a white-light time series
Abstract
An analysis is presented of a time series of 17 high-resolution, computer processed solar granulation pictures, obtained during the 'Spektro-Stratoskop' project from an altitude of 28 km. On each negative, a rectangle of 29.7 x 44.6 arcsec (where 1 arcsec corresponds to 733.3 km on the sun) was scanned with a microphotometer, and the digitized intensities (200 x 300/frame) were corrected for instrumental blurring by means of a two-dimensional deconvolution. Numerical data were used to generate power spectra, correlation coefficients, brightness histograms, and contour plots, and a simplified morphological model was used to interpret the data. Major conclusions include the following: (1) granular rms brightness fluctuation at 500 nm equals 9.9%; (2) mean granular contrast at 500 nm equals 21.9%; (3) fractional area of granules equals 47.1%; and (4) the peak at 3.4/Mm exhibited by previous power spectra is resolved into three components with wavenumbers 2.0/Mm, 4.4/Mm, and 7.4/Mm.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- June 1981
- Bibcode:
- 1981A&A....99...90W
- Keywords:
-
- Balloon-Borne Instruments;
- Image Processing;
- Photosphere;
- Solar Atmosphere;
- Solar Granulation;
- Time Series Analysis;
- Brightness;
- Digital Data;
- Image Reconstruction;
- Power Spectra;
- Telescopes;
- Solar Physics