Measurements of the Sun's Radius at Calern Observatory

The twenty five year old Visual series of Francis Laclare observations of the Solar radius at the Côte d'Azur Observatory is revisited here, with the principle of data acquisition and treatment. It is the opportunity of recalling some basics in astrometry. The new series DORAYSOL of digital acquisition of the same radius is introduced as well as a definition of the Sun border, that can only at first approximation be considered independent of the atmosphere turbulence