The Swiss Optical Ground Station and Geodynamics Observatory Zimmerwald (Geostation Zimmerwald for short) provides observation infrastructure and/or observation services for Optical Observations (CCD) Space Debris, Asteroids, Comets Satellite Laser Ranging to dedicated satellites GNSS-Receivers (GPS-, GLONASS- and Galileo-signals; swisstopo) Earth Tide Gravimeter Institute for Geodesy and Photogrammetry ETH Zürich Various microwave instruments for atmospheric research   Register by sending an e-mail: mailto: info@ion-ch.ch