free-space laser communications: the japanese...

Free-Space Laser Communications: The Japanese Experience

Morio ToyoshimaMorio Toyoshima

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Morio ToyoshimaMorio Toyoshima

National Institute of Information and Communications Technology (NICT)

Email: [email protected]

ECOC, Vienna, AustriaECOC, Vienna, AustriaSept. 24, 2009Sept. 24, 2009

Outline• Introduction• Trends of data rates• Past and current optical space communication programs

in Japan– ETS-VI/LCE program

ECOC, Vienna, Austria, Sept. 24, 2009

– OICETS/LUCE program– Development of digital coherent receivers– Development of Quantum Key Distribution (QKD) terminals

• Japanese Data Relay Test Satellite (DRTS) at JAXA• About the wavelength selection• Concluding remarks

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ERS1 Radarsat1Envisat1

ERS2Spot5

IRS-1CSunsatJERS1

ADEOS1ADESO2

ALOSEOS-PM1Landsat4

Landsat5

Landsat7

Ikonos2Clark

Geo-Eye-1

TerraSAR-X

1.0E+08

1.0E+09

1.0E+10

bit/s

ec)

Trends of data rate for Earth observation satellite


Orbview2

Spot1Spot2

Spot3 Spot4IRS-1A

IRS-1B IRS P4

SunsatJERS1ADEOS1

ADESO2

MOS1aMOS1b Resurs-01 N3

Landsat1

Landsat2Landsat3 Terra

TRMM

GOES8

MeteosatSG

DFH49

GMS4GMS5

MT-Sat

Elektro1

1.0E+05

1.0E+06

1.0E+07

1970 1975 1980 1985 1990 1995 2000 2005 2010

Dat

a ra

te (

bit

Launch year

Earth observation satellite (LEO)

Earth observation satellite (GEO)

3

SILEX

OICETS

TerraSAR-X

Digitalcoherent

NeLS

1.0E+08

1.0E+09

1.0E+10

1.0E+11at

e [b

it/se

c]

Trends of data rate for space laser comm.


SILEX

ETS-VI

1.0E+04

1.0E+05

1.0E+06

1.0E+07

1990 1995 2000 2005 2010 2015

Launch year

Dat

a ra

te

Space qualifiedGround test

R&D on optical space communications in NICTETS-VI

LCEARTEMIS

OPALE(ESA)

GEO

GMS-2 GMS-3 GMS-4

Laser TrasmissionLaser Trasmission

ArAr laser+ COlaser+ CO22

OICETSLUCE

Optical TrackingOptical Tracking

GEOGEO--GNDGNDLaser Comm.Laser Comm.

GEOGEO--LEOLEOTwoTwo--way Laser Comm.way Laser Comm.

NeLS (NICT)Development


1990 2000 2010

LEO

GND

1980

Laser TrasmissionLaser TrasmissionExperimentExperiment

Laser RangingLaser Ranging

LUCE(JAXA)LEOLEO--GNDGND

TwoTwo--way way Laser Comm.Laser Comm.

NICT OGS (1.5m Telescope System)

AJISAI,AJISAI,ADEOS, ADEOSII,ADEOS, ADEOSII,LRE, ALOS, ETSLRE, ALOS, ETS--VIIIVIII

LEOLEO--GNDGND1.064 1.064 μμm m Laser TrackingLaser Tracking

Laser communications experiment using ETS-VI satellite (Dec. 1994 - July 1996)

• 1 Mbps IMDD bi-directional optical link experiment at a distance of ~40,000 km.

• 22 kg, 60 W onboard equipment verification


NICT/CRL Optical Ground Station

ETS-VI

Laser Communication Equipment (LCE)

6

Uplink and downlink laser beams for the ETS-VI satellite


Uplink laser beam from the NICT/CRL ground station

Downlink laser beam fromthe ETS-VI satellite

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OICETS satellite system

Optical Antenna

1.8 m1.8 m


Solar Array PaddleS-band Antennas

Satellite size 0.78x1.1x1.5 m

Mass 570 kg

Mission life 1 year

Altitude 610 km (circular)

Inclination 98 deg.

9.4 m9.4 m

Courtesy of JAXA

Laser communication terminal

Optical Antenna

EL Cable RapCable Wrap

ＨＣＥ

Azimuth (AZ) axis

Size 1.24×0.98×0.57 m

Mass Approx. 140 kg

Power consumption

Approx. 220 W

(during communication)

Courtesy of JAXA


Elevation (EL) axis

EL Gimbal Yoke

AZ Motor/Encoder

AZ Cable Rap

Inter Optics Part

EL Encoder

EL Motor

Cable Wrap

LUCE (Laser Utilizing Communications Equipment)LUCE (Laser Utilizing Communications Equipment)

Configuration of the experiment

Laser communication RF link (Satellite control)

ESA/ARTEMISOICETS/Kirari satellite


NICT (Japan) JAXA Kirari operation center(Tsukuba Space Center)

(Satellite control)

NASA JPL (U.S.)

DLR (Germany)

ESA (Spain)

International cooperation International cooperation between 4 OGSsbetween 4 OGSs

OICETS scenario

- Event -• Separation (changed)• Spin mode (changed)• Solar paddle deployment• Sun acquisition mode• Earth acquisition mode


• Earth acquisition mode• Launch lock off• Trajectory control• 3-axis stabilized attitude

control• Optical communication

with ARTEMIS• Optical communication

with NICT ground station

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Acquisition and tracking

Wide FOV CCD

CCD at Tx bench


FOV CCD Tx bench

Guide Telescope

CCD at Rx bench

Statistics of link establishment

Link established32%

Cloud25%

Spacecraft/operation error

7%

• Probability of success during all the experiments– NICT: 49.1 %– NASA JPL: 57.1 %– DLR: 60.0 %– ESA: 88.9 %


Link established (interrupted by

clouds)12%Link established

through thick clouds

5%

Rain21%

• Total probability of success between Earth and space:– 1-[(1-0.491)x(1-0.571)

x(1-0.60)x(1-0.889)] = 0.9903

• Four OSGs combination will help to download massive data from space with the probability of 99%.

Statistics of link establishment at NICT

Digital coherent receiver aiming for free-space laser communications

• Interoperability between IMDD and coherent technologies (1.064 & 1.5 μm) which allow us to communicate with ESA’s coherent terminals

• Signal fading caused by atmospheric turbulence can be compensated by the real-time digital signal processing (DSP).

• No optical PLL because commercially available local lasers can be used as free-running conditions.

• Optical devices at 1.5 μm are available.


Mod. formats: - IMDD- Coherent (1.0 & 1.5 μm)

Development of real-time digital coherent receiver~ Implementation of FPGAs ~

• 3 Gbps BPSK real-time coherent receiver in 2007– 2xADC: NS ADC083000

– FPGA: Xilinx Virtex-4/FX100

• 6 Gbps BPSK real-time coherent receiver in 2008– 4xADC: NS ADC083000

– 2xFPGA: Xilinx Virtex-4 & Virtex-5


– 2xFPGA: Xilinx Virtex-4 & Virtex-5

• Dual wavelengths free-space optical 90 degree hybrid– Two wavelengths (1.064 &1.5 μm) can be received without no

reconfiguration.– High I/Q extinction ratio: >50 dB

Development of QKD terminals~1-km free-space QKD experiments~

AliceAlice

NICTNICT

Hotel Mets KokubunjiHotel Mets Kokubunji

NICTNICT

BobBob


AliceAlice

Bob

AliceAlice~~1km1km

JR KokubunjiJR Kokubunjistationstation

Japanese Data Relay Satellite at JAXA

Data Relay Test Satellite “Kodama”

Data Relay Satellite

“ALOS” ALOS2

Low earth orbit1~2 DRTSs will be in operation.


http://www.jaxa.jp/press/2009/09/20090909_sac_oicets.pdf ( in Japanese)

“ALOS” ALOS2

ALOS3

Research Development

R&D of next generation optical intersatellite technology

Optical terminal can be compact and several ones can be onboard GEO.

Wavelength:1.064 umData rate: 2.5 GbpsMod: Homodyne BPSKPLL: Optical PLL

1~2 DRTSs will be in operation.

Trends of data rate and the receiver sensitivity

TerraSAR-X

Digital coherentNeLS

DPSK(2003)RZ-AMI(2003)RZ-DPSK(2004)

DPSK(2008)

1.0E+09

1.0E+12

1.0E+15at

a ra

te [b

it/s]

WDM Technique

1064 or 1550 nm

1550 nm


ETS-VIOICETS SILEX

1.0E+03

1.0E+06

1.0E+09

1.0E+00 1.0E+01 1.0E+02 1.0E+03 1.0E+04

Da

Sensitivity@BER=10-6 or 10-9 [photons/bit]

Space qualified

Ground test

Classical limit(Shannon limit)

800 nm

Concluding Remarks• ETS-VI/LCE successfully demonstrated the ground-to-

satellite optical communication experiments.• OICETS/LUCE succeeded to establish the inter-satellite

and ground-to-satellite links. The precise acquisition and pointing technology necessary for a LEO to GEO link was confirmed.


• International cooperation is important for site diversity.• Current R&D was presented related to the digital

coherent receiver and the QKD experiments.• For the wavelength selection, 1.064 μm will be used at

this moment. However, 1.5 μm technology will be the next lead for the higher data demands even in space laser communications.

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free-space laser communications: the japanese...

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