Satellites for earth observation, such as the Sentinel satellites in ESA’s Copernicus program, collect a lot of data by their high resolution detectors. This data has to be down-linked from these satellites to ground stations.
At the moment this is done by radio frequency (RF) communication, which is limited to 10 Gbit/s per channel and requires licensed frequencies. Recently free space optical (FSO) communication has the potential to increase the data rate to more than 120 Gbit/s and has been proven with satellites. Furthermore FSO requires no licensed frequencies and offers the advantage of reduced mass and energy consumption of the emitter at the satellite. Therefore, this technology has a huge potential for future satellite communication.
One of the major challenges of FSO satellite communication is turbulence mitigation, which is most effectively done using adaptive optics (AO). High-end telescopes for astronomy, like the E-ELT, use complex AO-systems with hundreds of actuators to increase resolution and make faint stars look brighter.
AO is an active research area that has proven its potential, particularly on big telescopes, and is on the verge of entering also other domains, such as medical diagnostics or mid-sized and smaller telescopes for the commercial and private sector. In FSO communication, AO systems enable to better focus the laser beam onto the detector to decrease spot size, increase the intensity at the detector and reduce scintillation, thereby reducing the bit error rate (BER).
Contents and Goals
The proposed project aims at the development and integration of a tailored AO-system for the telescopes of the industrial partner, ASA Astrosysteme GmbH. By an integrated mechatronic system design the aim is to realize both a high bandwidth AO system as well as a cost effective solution, preferably using commercially available components. This will be achieved by optimal system integration, which takes the interplay between the system requirements, the properties of the individual components, and the real-time control system into account.
In the future, this project will enable ASA to extend their product portfolio and position them internationally in a leading role for the new and currently upcoming market for commercial FSO satellite communication. This will have a positive effect for the company as well as the Austrian high-tech sector, employment and economy.
The resulting telescope system will enable to establish a more stable laser link between corresponding satellite and the optical ground station. This will enable to utilize this laser link for FSO satellite communication at unprecedented data rates.
The resulting telescope system will enable to establish a more stable laser link between corresponding satellite and the developed optical ground station. This will enable to utilize this laser link for FSO satellite communication at unprecedented data rates while reducing energy consumption of the emitter at the satellite and working at optical frequencies that do not require licensing.
Vienna University of Technology - Institute for Automation and Control Engineering
ASA Astrosysteme Austria
Vienna University of Technology
Institute for Automation and Control Engineering
Univ.-Prof. DI Dr. Georg Schitter