One-dimensional speckle interferometry of the solar granulation

Rapid photoelectric scans of disk-center solar granulation were made with a telescope with a 'one-dimensional' (2 cm x 50 cm) aperture in a direction parallel to the long dimension of the aperture. The theory of speckle interferometry applied to the observations allowed the shape of an axial cut through the two-dimensional spatial power spectrum of the granulation to be determined between 0.3 and 1.4 cycles per arcsec, in spite of seeing of the order of three sec. The observed exponential decrease of the granulation power spectrum with increasing spatial frequency favors a convective model of solar granulation.