2D-filtering and restoration of radio-maps of the 8 mm and 13 mm solar disc

Abstract

The solar disc was scanned at 8 and 13 mm using the computer controlled 22 m radio telescope of Simes. A radial shift invariant Wiener filter was applied to restore the measured matrix and improve the image. The problems of limb darkening and of the brightening of polar regions are discussed. A good correlation between the restored bright regions and the magnetically enhanced regions as observed in the optical range is apparent.