Optical Free-Space Communications Downlinks from Stratospheric Platforms - Overview on STROPEX, the Optical Communications Experiment of CAPANINA

Kurzfassung

This paper describes the current (April 2005) status of the STRatospheric OPtical Downlink EXperiment (STROPEX) which is part of the European Union funded research project “CAPANINA” (Communications from Aerial Platform Networks delivering Broadband Communications for All). CAPANINA is one of Europe's initiatives to develop the promising technology of HAPs (High Altitude Platforms) which can one day complement - and where economically reasonable replace - terrestrial or satellite based wireless services. The aim of STROPEX is to perform measurements to characterize the propagation channel for high-speed optical free-space communication. In addition, a downlink from a stratospheric carrier (alt. 22km) will be researched. Therefore both, the optical flight terminal and the optical tracking-receiver ground station had to be developed from scratch.