A novel ground-based receiver for EDRS

Abstract

Within the frame of European Data Relay System (EDRS) upgrades, ESA is developing technologies for reliable optical communication links through atmospheric turbulence. This includes adaptive optics for wave-front correction on the downlink (and pre-distortion on the uplink), but a promising alternative to adaptive optics is a self-homodyne multimode differential phase shift interferometer, which doesn’t require phase-integrity of the incoming signal. Moreover, a custom-made avalanche photo detector (APD) with 80μm active area was developed for efficient conversion into an electrical signal. Field test were carried out from ESA’s optical ground station (OGS) with a laser communication terminal (LCT) onboard the Alphasat satellite in geosynchronous orbit.