LESUEUR , Patrick

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...

Ground based solar observations are strongly affected by optical turbulence. The concept of a new instrument which allows to measure both spatial and temporal parameters of atmospheric turbulence has been proposed in the late 90s. The instrument MISOLFA (Moniteur d'Images Solaire Franco-Algérien) is based on this concept and has been developped...

PICARD SOL is the ground component of the PICARD mission and is operational since March 2011. A set of instruments including the replica of the space instrument and several atmospheric monitors was set up at Calern observatory in order to compare solar radius measured in space and on ground and to better understand and calibrate atmospheric...

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...