Lasercomm Activities at the German Aerospace Center’s Institute of Communications and Navigation

Kurzfassung

The German Aerospace Center (DLR) has a heritage of more than 25 years in working on optical inter-satellite and satellite-to-ground links. The Institute of Communications and Navigation (IKN), as a research organization of DLR, has developed coherent homodyne BPSK transmission schemes with world record sensitivity as they are now implemented in the space-proven Laser Communication Terminals (LCT) for the European Data Relay System (EDRS). Further research being pursued at IKN includes the development of transmission systems optimized for atmospheric scenarios such as LEO downlinks, aircraft downlinks and inter-HAP links (High Altitude Platforms). For such scenarios with extreme index-of-refraction turbulence, robust adaptive optics technologies have been investigated and suitable data transceivers have been tested. Furthermore, several verification campaigns with prototype flight terminals and optical ground stations (fixed and transportable) have been performed in recent years, providing a large data basis for optimizing the long-range FSO technology.