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Optical Free-Space Communication Activities at the German Aerospace Center’s Institute of Communications and Navigation … selected topics Dirk Giggenbach
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
Selection of Activities of DLR‘s Optical Communications Group
- OSIRIS – Small LEO Downlink Terminal
- Aeronautical Downlink System
- Optical Ground Stations
www.DLR.de • Chart 2
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
Köln
Lampoldshausen
Stuttgart
Oberpfaffenhofen
Braunschweig
Göttingen
Berlin-
Bonn
Trauen
Hamburg Neustrelitz
Weilheim
Bremen-
DLR – Sites in Germany
Stade
Augsburg
Optical Communications Group, Institute of Communications and Navigation
DLR – the German Aerospace Center
www.DLR.de • Chart 3
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach www.DLR.de • Chart 4
Optical Communications Group
- Staff: 12 Scientists + PhD-Students
- Facilities: Optical Ground Station Oberpfaffenhofen (OGS-OP), Transportable Optical Ground Station (TOGS), Adaptive Optics Lab
- Experimental Projects: Aircraft Laser Terminal, Miniaturized Satellite Terminals (OSIRIS), Aircraft-Satellite Links, Atmospheric Index-of-Refraction Measurements
- Scientific Projects: Adaptive Optics for FSO, Frequency Dissemination through the Atmosphere, GEO Feeder Links, Electro-Optical Transceivers for FSO
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
OSIRIS – Laser Downlink Terminals for Small LEO Satellites
www.DLR.de • Chart 5
1) Open-loop pointing by satellite-bus‘ star tracker
2) Tracking sensor + Data uplink
3) Pointing unit
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach www.DLR.de • Chart 6
OSIRIS - Laser Sources
High Power Laser Diode (HPLD) - Weight: ~150 g - Up to 155 Mbit/s @ 0,1 W Optical Power - Power Consumption: ~8 W
Erbium Doped Fiber-Amplifier (EDFA) Weight: ~1 kg Up to 2,5 Gbit/s @ 1 W Optical Power Power Consumption: ~35 W Space-Qualification ongoing
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach www.DLR.de • Chart 7
OSIRIS - Tracking Devices
Tracking Device based on 4QD Higher pointing accuracy Better link-budget
Pointing done by satellite-bus
4QD: Four Quadrant Detector
Pointing Unit for aeronautical applications
Dedicated Pointing Unit Pointing independent from satellite attitude Goal:
„Coffee Cup“ sized optical comms terminal < 5 kg < 50 W (only during downlink)
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
OSIRIS-Payload for Biros (incl. 4QD-Tracker)
www.DLR.de • Chart 8
Optical Downlink
Tracking-Sensor and Uplink
PPU: Pre-Processing Unit
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
OSIRIS - Accomodation on BiROS
www.DLR.de • Chart 9 > PrOSIRIS > C. Fuchs
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
OSIRIS Scientific Applications
- Feasibility of operational data downlinks with >1Gbps (space- and ground data handling)
- Verification of Ground Station
Diversity Concepts
- Test Source for Adaptive Optics - Downlink Channel Measurements at
1550nm
Transmission of high-resolution images
OGS-Network over Germany
European and Worldwide OGS-Locations red/yellow: areas with low/high cloud probability
International cooperation is encouraged!
www.DLR.de • Chart 10
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
Aeronautic Downlinks
www.DLR.de • Chart 11
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
Aeronautic Data Downlinks at 1540/60nm IM/DD
- Coarse pointing unit outside of aircraft
- Optical bench and electronics inside
- Bit-rates up to 1,25 Gbit/s
- Link distance up to 150km
www.DLR.de • Chart 12
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
Terminal-Details
www.DLR.de • Chart 13
Control electronics and tracking opto mechanics
inside the Dornier-228 experimental aircraft
Coarse Pointing Assembly (30mm
aperture)
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
3D-Analysis of Atmospheric Turbulence Structure by Aircraft-Downlink
20km 40km 80km
1km
2km
3km
www.DLR.de • Chart 14
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
Synchronized Turbulence Measurement Devices provides Complete Optical Field
www.DLR.de • Chart 15
Pupil SHS Phase Focus
FFT
Capturing synchronized triggered and time-stamped InGaAs-camera frames, with Aircraft- and Satellite-Downlinks at 1550nm / 1064nm
+
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
Optical Ground Stations
www.DLR.de • Chart 16
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
Optical Ground Station Oberpfaffenhofen / OGS-OP
- 4,5m Clamshell-Dome on the institute‘s roof (20m above ground level)
- 40 cm Cassegrain-Telescope
- Operations- and Coudé-Room beneath
www.DLR.de • Chart 17
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
Turbulence Measurement Devices at OGS-OP
www.DLR.de • Chart 18
Optical system behind 40cm aperture
Receiver front end
Pupil camera
Focus camera
DIMM
Shack-Hartmann
Tracking camera
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach www.DLR.de • Chart 19
Transportable Optical Ground Station (TOGS)
- 60cm custom Alumnium-Mirror
- Drives developed by DLR-Institute for Robotic and Mechatronic
- GPS-assisted Leveling
- Height >3m ( eye-safety)
- Globally deployable (size fits air-freight container)
- Optimized for Aircraft- and LEO-Downlinks
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
TOGS-Operation - Calibration - GPS- or orbit-assisted acquisition - Beacon-control - Wide-FoV-Cam - Near-FoV-Tracking-Cam
www.DLR.de • Chart 20
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach www.DLR.de • Chart 21
Transport Van with Operations Rooms for TOGS
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
Other topics
- Adaptive-Optics for FSO under strong scintilaltion
- Frequency Dissemination through the Atmosphere
- Geostationary Optical Feeder Links (Availability, Transmission Formats)
- High-Speed FPGA-based Data-Transceivers
- Quantum Key Distribution (demonstrated from Aircraft)
www.DLR.de • Chart 22
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
Thank You for Your Attention Questions?
www.DLR.de • Chart 23
> Optical Free-Space Communication Activities at DLR-IKN > D. Giggenbach
www.DLR.de • Chart 24