LASER COMMUNICATION FOR EDRS - CCSDS.org Completed (Closed WGs)/Optica… · Laser Communication Terminals for … 17.04.2012 Laser Products, Dr. Robert Lange 22 … Alphasat (GEO)

PIONEERING WITH PASSION

©Tesat-Spacecom GmbH & Co.KG 2010

1


PROPRIETARY INFORMATION

©Tesat-Spacecom GmbH & Co.KG reserves all rights including industrial property rights,

and all rights of disposal such as copying and passing to third parties

LASER COMMUNICATION FOR EDRS

LEO-GEO, LEO-GROUND, GEO-GROUND

Robert Lange (Tesat-Spacecom)



TESAT LCT Ready for Commercial Operation

17.04.2012 Laser Products, Dr. Robert Lange 2

Figure courtesy of ESA _ P. Carril Figure courtesy of ESA _ P. Carril

Applied in EDRS

Increased availability

12 h per day

instead of

several minutes

Increased data rate

Up to 10 Gbps

1.8 Gbps for EDRS

Figure courtesy of ESA_P. Carril



EDRS LCTs Based on Links Verified In-Orbit !


NFIRE TerraSAR-X Optical inter-satellite links

Inter-satellite links Space-to-ground links Ground-to-space links at data rates of 5.625 Gbps



Most sensitive

Highly immune

against sun light

Homodyne BPSK maintains the optical link

even with the sun in the Field Of View !

LCT: Based on Homdyne BPSK




Designed for lowest fit rate

by laser diode redundancy

• Hot: Laser diode bench

• Cold: Redundant benches

Pump Module Reliability

> 0.999 in 15 years

Homodyne BPSK: Reliable




Nd:YAG laser

Frequency stability ensured by MISER principle

Polarization maintaining mono-mode fiber coupled

Homodyne BPSK: Robust




Homodyne BPSK: Easy Handling


Easy handling interface

Receiver Front End performing • Spatial acquisition • Frequency acquisition • OPLL control signals • Tracking • Demodulation



LCT operational in-orbit

Verified as reliable and robust

Extensive test and measurement campaigns

have proven calculated link budgets to be very accurate

FM lasers delivered to ESA and US aero-space industry

Heritage:

GIFTS, ALADIN, LISA, ATLID, several classified programs ...

Homodyne BPSK: Technology Readiness Level 9




Laser Communication Terminal: In-Orbit Verification


LEO – LEO Links

Data Rate 5.625 Gbps

Range Up to 5,100 km

Target Bit Error Rate 10-8

Transmit Power 0.7 W

Telescope Diameter 125 mm

Mass 35 kg

Power Consumption ~ 120 W max.

Envelope ~ 0.5 x 0.5 x 0.6 m3



In-Orbit Verification: LCT Accommodated on TerraSAR


LCT integrated on TerraSAR-X (LEO satellite) Launched June 14th 2007 Status: LCT fully operational



In-Orbit Verification: LCT Accommodated on NFIRE


LCT integrated on NFIRE (U.S. LEO satellite) Launched April 23rd 2007 Status: LCT fully operational



In-Orbit Verification: First ISL dated Feb. 21st 2008


TerraSAR-X

NFIRE



In-Orbit Verification: Inter-Satellite Link


Bit errors measured in one of the 25 data channels of 225 Mbps

Only one bit error measured for one of the LCTs within 400 s

Bit error rate better than 10-11



In-Orbit Verification: Ground Station




In-Orbit Verification: Space-to-Ground Link


Bit error rate still low, but increased due to atmospheric distortion

Measurement campaign running to optimize communication link by

use of adaptive optics



In-Orbit Verification: Ground-to-Space Link


First link (not yet optimized !) already verifies feasibility of uplink

Communication at amazing low bit error rates of 10-5

Bit error rate increase due to atmospheric disturbance



Laser Communication Terminal: Optical GEO Relay


LEO – GEO – GEO Links

Data Rate 1.8 Gbps

Range Up to 45,000 km

Target Bit Error Rate 10-8

Transmit Power 2.2 W

Telescope Diameter 135 mm

Mass 50 kg

Power Consumption ~ 160 W max.

Envelope ~ 0.6 x 0.6 x 0.7 m3



The Optical GEO Relay as Used for Alphasat


NFIRE TerraSAR-X Optical inter-satellite links

Inter-satellite links Space-to-ground links Ground-to-space links at data rates of 5.625 Gbps



LCT: GEO-LCT for Alphasat




Alphasat LCT, the GEO Relay Demonstrator


NFIRE TerraSAR-X



GEO-to-Ground Links at 1.8 Gbps and more….


Data rate increased by large telescope diameter (40 cm)

Requires adaptive optics

Deformable mirror

(12 x 12 elements, element size 0.45mm x 0.45mm)

Verified under worst case conditions with a coherent beam running horizontally across more than 20 km through the atmosphere, 1 m RX aperture



Laser Communication Terminals for …


… Alphasat (GEO)

… Sentinal 1-a (LEO)

… Sentinal 2-a (LEO)

… EDRS-A (GEO)

… EDRS-C (GEO)

… Framce Contract with ESA



Summary


Laser Communication

based on homodyne BPSK

ready for

commercial operation



Tesat-Spacecom

Gerberstraße 49

71522 Backnang

For further information please contact:

Thank you very much for your attention !

Dr. Robert Lange

[email protected]

+49 7191 930 1267


The LCT development and the in-orbit verification is supported by the German Space Agency DLR/BMWi under 50YH0202 and 50YH063

mailto:[email protected]

Documents

LASER COMMUNICATION FOR EDRS - CCSDS.org Completed (Closed WGs)/Optica… · Laser Communication Terminals for … 17.04.2012 Laser Products, Dr. Robert Lange 22 … Alphasat (GEO)