The observatory is a 1-meter Coudé telescope with a field of view of 0.7 degrees, supported by an English cross-axial mount inside a dome 12.5-meters in diameter. Its main purposes are:
to make scientific astronomical night observations.
It is equipped with a cryogenically cooled mosaic CCD-Camera of 4k×4k pixels. The detection threshold is between 19th and 21st magnitude, which corresponds to a capability to detect space debris objects as small as 10 cm in the geostationary ring. As a large part of the observation time is dedicated to space debris surveys, in particular the observation of space debris in the geostationary ring and in geostationary transfer orbits, the term ESA Space Debris Telescope became used very frequently. Space debris surveys are carried out every month, centered on New Moon.[citation needed]
Since 2006, the telescope has also been used as a receiver station for quantum communication experiments (such as testing Bell's inequality, quantum cryptography, and quantum teleportation), with the sender station being 143 km away in the observatory on La Palma.[1] This is possible because this telescope can be tilted to a near-horizontal position to point it at La Palma, which many large astronomical telescopes are unable to do.
