e2v CCD imaging sensors launched into space onboard the CNES Picard satellite

For the French version of this press release, please click here.

On 15th June 2010 an e2v Charge Coupled Device (CCD) imaging sensor was launched into space onboard the CNES (Centre National d’Etudes Spatiales) microsatellite Picard, on its 2-3 year mission to study the Sun. This mission was developed by CNES in partnership with the LATMOS (Laboratoire Atmosphere-Milieu-Observations Spatiales, formerly Service Aéronomie) from CNRS (Centre National de la Recherche Scientifique). An e2v CCD imaging sensor was selected to equip the focal plane of Picard’s SODISM instrument.

SODISM (SOlar Diameter Imager and Surface Mapper) is a whole Sun imaging telescope that uses an e2v CCD to measure the solar diameter and its shape with an accuracy of a few milliarcseconds. It will also perform helioseismologic observations to probe the solar interior. The e2v CCD42-80 imaging sensor is a frame transfer matrice of 2048 x 4096 pixels, 13.5-µm square pixel size, with back-thinned illuminated technology for optimum sensitivity. It works in UV light and in the MPP (Multi Phase Pin) mode. This mode, associated with a temperature regulated at -40° C, reduces the dark currents to a very low level. The sensor also has high quantum efficiency in the spectral range (370 nm, 950 nm).

Picard’s mission is to study solar variability in order to improve knowledge of the Sun and to understand the influence of solar activity on Earth’s climate. It is named after Jean Picard, the 17th Century French astronomer who took a series of scientific measurements of the solar diameter during a period known as the Maunder minimum (1645-1715), when mean temperatures dropped on Earth. These measurements are important as they show a variance between this period and when the Sun was active – prompting the question “are diameter and activity linked?”. Picard is designed to simultaneously measure various aspects of the Sun including; the speed it rotates, the radiations it emits, the presence of sunspots and its shape and diameter. This data will help to evaluate the influence the Sun has on Earth’s temperature and to what extent it contributes to global warming.

The Picard microsatellite is equipped with several instruments, including SODISM, which was developed under LATMOS responsibility using an e2v CCD procured under CNES contract for the Corot project. The integration of the SODISM instrument on CNES Myriade Microsatellite Platform was performed by CNES .

Alain Bardoux, Head of Detection Chain Department from CNES said “Thanks to the high photo response achieved via back-thinned technology and the e2v sensors very low dark current, it is possible to meet the very demanding signal to noise requirement for the Picard mission.”

Jon Kemp, Marketing & Applications Manager for e2v’s Imaging division said, “e2v is delighted to again supply high quality image sensors to CNES. The Picard mission will play an important role in understanding our Sun and how its activity impacts our lives on Earth.”