Speckle Interferometry Technique Applied to the Study of Granular Velocities
Abstract
The correlation between intensity and velocity in solar granulation is studied. A speckle experiment which consisted of recording signals collected by two photomultipliers set 0.25 A apart on the wings of the Fe 5233 A was conducted at the McMath main telescope of the Kitt Peak National Observatory on July 1980. The data was processed, and brightness and velocity spectra and brightness-velocity cross spectrum matrices are computed. A cross-analysis technique is applied to the brightness power spectrum. It is observed that the phase of the cross spectrum reveals where the velocity/brightness correlation is accurately measured; between 0.5/Mm and 6/Mm the correlation is positive. A linear coherence function is calculated and the amplitude of the coherence function reveals a maximum linear correlation coefficient of about 0.6 for a wave number of about 3.5/Mm, and a steep decrease in lower anad higher wave number.
- Publication:
-
High Resolution in Solar Physics
- Pub Date:
- 1985
- DOI:
- 10.1007/BFb0022400
- Bibcode:
- 1985LNP...233..103A
- Keywords:
-
- Photosphere;
- Solar Granulation;
- Speckle Patterns;
- Brightness;
- Line Spectra;
- Photomultiplier Tubes;
- Power Spectra;
- Solar Instruments;
- Solar Physics