The Zimmerwald Observatory (also: Swiss Optical Ground Station) is the largest professional observatory in Switzerland. It hosts 5 telescopes with apertures from 20 cm to 1 m. Its main tasks are twofold: Satelllite laser ranging to determine precise distances to satellites and optical observations, for example of stars and other objects.
The observatory also hosts a wide array of partner experiments, such as atmospheric measurements, an Earth tide gravimeter, and GNSS-antennae operated by Swisstopo.
