Published online by Cambridge University Press: 12 April 2016
The French astronomical satellite D2B is to be launched on September 1975. The spin axis is constantly oriented towards the sun with an accuracy of ± 30 arc min. The ERC experiment (field recognition) wii provide imager in three spectral intervals of a region centered at the anti-sun point and having a diameter of 10°. The scanning of this region is realized by a combination of the spin motion of the satellite and internal electronic scanning. This experiment includes a catadioptric objective [optimized Kern telescope) with a field of 3° × 6° and an image dissector which analyses the image.