FODIL , M.

The series of measurements of the Solar radius at CALERN site of the observatoire de la Côte d'Azur (OCA) spans about 30 years. Measurements of the Sun were first achieved visually by the same single observer, then gradually grew more man-independent with the use of CCD acquisitions. The DORAYSOL instrument was designed and built up to keep...

Developed at the Observatoire de la Côte d'Azur (OCA) within the framework of the PICARD space mission (Thuillier et al., 2006) and with support from the french spatial agency (CNES), MISOLFA (Moniteur d'Images Solaires Franco-Algérien) is a new generation of daytime turbulence monitor. Its objective is to measure both the spatial and temporal...

The Franco-Algerian Monitor of Solar Images (MISOLFA) was developped in order to study the effect of optical turbulence on diameter measurements from ground-based solar observations. Some first results obtained with MISOLFA are presented.

PICARD is a space mission developed mainly to study the geometry of the Sun. The satellite was launched in June 2010. The PICARD mission has a ground program which is based at the Calern Observatory (Observatoire de la Côte d'Azur). It will allow recording simultaneous solar images from ground. Astrometric observations of the Sun using...

For the past thirty years, modern ground-based time-series of the solar radius have shown different apparent variations according to different instruments. The origins of these variations may result from the observer, the instrument, the atmosphere, or the Sun. Solar radius measurements have been made for a very long time and in different ways....

PICARD is a space mission launched in June 2010 to study mainly the geometry of the Sun. The PICARD mission has a ground program consisting mostly in four instruments based at the Calern Observatory (Obser-vatoire de la Côte d'Azur). They allow recording simultaneous solar images and various atmospheric data from ground. The ground instruments...

For the last thirty years, ground time series of the solar radius have shown different variations according to different instruments. The origin of these variations may be found in the observer, the instrument, the atmosphere and the Sun. These time series show inconsistencies and conflicting results, which likely originate from instrumental...