Optical Ground Station (OGS) is a terrestrial optical terminal that communicates via Free Space Optics (FSO) to another terminal located either on land, airborne, or in space. Optical Ground Stations may be fixed or mobile (TOGS).
The European Space Agency has constructed an OGS in Tenerife, Spain which is designed to demonstrate astronomy measurements with new detectors while observing space for debris. 
Optical Ground Station Oberpfaffenhofen (OGS-OP) is a DLR optical ground station located near Munich. It has been used in tests with the Japanese OICETS Satellite with a 50-Mbit/s signal at 847 nm on its 40-cm Cassegrain telescope.