The Euclid payload consists of a 1.2m aperture telescope with two instruments: the visual imager (VIS) and the near-infrared spectrometer and photometer (NISP).

Both instruments share a large common field of view. VIS provides high quality images to carry out the weak lensing galaxy shear measurements. NISP performs imaging photometry to provide near-infrared photometric measurements for photometric redshifts, and also carries out slitless spectroscopy to obtain spectroscopic redshifts. The telescope and instrument designs are challenging, but proven heritage from, for example, Gaia and JWST ensures high confidence to deliver the performance required.
 

	Introduction
	Telescope