Building the Euclid survey
Jean-Charles Cuillandre

Euclid is a space-based optical/near-infrared survey mission of the European Space Agency (ESA) designed to investigate the nature of dark energy, dark matter and gravity by observing their signatures on the geometry of the Universe and on the formation of large scale structures over cosmological timescales. To reach these core scientific goals, Euclid will use weak gravitational lensing, which requires the measurement of the shape and photometric redshifts of distant galaxies with a wide field visible imager, and galaxy clustering, based on the measurement of the 3-dimensional distribution of galaxies through their spectroscopic redshifts obtained with a near infrared wide field slitless spectrograph. The mission is scheduled for launch late 2020 with a 6-year duration, and it critically relies on an ambitious ground-based observing campaign that will provide the deep multi-band (ugriz) photometry needed over the 15,000 square degrees of the nominal space survey. This seminar aims at presenting the overall on-going effort in building the challenging space survey and the complementary ground-based surveys needed for the mission to achieve its goals.