Overview of the Small Optical TrAnsponder (SOTA) …...One of the smallest optical-communication terminals for spacecraft equipment SOCRATES衛星に組み込まれた Mass : 6.2

National Institute of Information and Communications Technology

Overview of the Small Optical TrAnsponder (SOTA) Project

Space Communications Laboratory Wireless Networks Research Center

National Institute of Information and Communications Technology (NICT)


ERSEnvisat1

TRMM

Radarsat1

Spot

IRS-1A,1B,1CAS1000

JERS1

ADEOS

ALOS

MOS 1AMOS 1B

EOS-PM1

LandsatTerra

Ikonos2

Orbview2

Orbview4Orbview3

TOMS-EP

GeoEye-1

TerraSAR-X

AlSat

TopSat

PRISM

UK-DMC1UK-DMC2

WorldView1

QuickBird2

EROS-BKompsat2

EROS-A

Formosat2

RazakSat-1

EarlyBird

Lewis

MicroLabSat

Cute-I

Cute-1.7

1.0E+03

1.0E+06

1.0E+09

1.0E+12

1 10 100 1000 10000

Dat

a ra

te fo

r Ear

th o

bser

vatio

n sa

tellit

es [b

ps]

Satellite mass [kg]

Satellite mass v.s Data rate of Satellites

ever launched

Micro satellites

2


ERSEnvisat1

TRMM

Radarsat1

Spot

IRS-1A,1B,1CAS1000

JERS1

ADEOS

ALOS

MOS 1AMOS 1B

EOS-PM1

LandsatTerra

Ikonos2

Orbview2

Orbview4Orbview3

TOMS-EP

GeoEye-1

TerraSAR-X

AlSat

TopSat

PRISM

UK-DMC1UK-DMC2

WorldView1

QuickBird2

EROS-BKompsat2

EROS-A

Formosat2

RazakSat-1

EarlyBird

Lewis

MicroLabSat

Cute-I

Cute-1.7

1.0E+03

1.0E+06

1.0E+09

1.0E+12

1 10 100 1000 10000

Dat

a ra

te fo

r Ear

th o

bser

vatio

n sa

tellit

es [b

ps]

Satellite mass [kg]

Laser-Communication Infrastructure for Micro-Satellites

Optical ~Mbps

New area covered by SOCRATES/SOTA

Short-term space verification by micro satellites

(2~3 years)

Gbps Mid/small satellites

High-end communications by mid/small satellites

(5~ years)

~100Mbps

Quasi-real-time data transmission via site diversity

Offline transmission

only

RF ~kbps

Micro satellites

3


Research Activities on Space Laser Communications in NICT

1995

ETS-VI (KIKU6) 1994-1995

OICETS (KIRARI) 2005-2009

SOCRATES 2014-2016 RISESAT

with Tohoku Univ.

ETS-IX

http://www.jaxa.jp/projects/sat/oicets/index_j.html

2005 2010 2015 2020

2017?

2021

2000

http://www.jaxa.jp/projects/sat/ets6/index_j.html

GEO-GND

GEO-LEO

LEO-GND

LEO-GND

LEO-GND

GEO-GND

4

http://www.jaxa.jp/projects/sat/oicets/index_j.html

http://www.jaxa.jp/projects/sat/ets6/index_j.html


Data rate : 1 〜 10 Mbps Wavelength : Tx 0.8 / 0.98 / 1.55 µm Rx 1.064 µm Beam pointing : Az - El mount + Fine-pointing mirror

One of the smallest optical-communication terminals for spacecraft equipment

SOCRATES衛星に組み込まれたSOTA Mass : 6.2 kg (including optical and control part)

Overview of SOTA

5

SOTA: Small Optical TrAnsponder


Development of SOTA

Fine sensor

Transmitting Laser

Coarse sensor QKD lasers

Receiver

Mass: 5.3 kg, Power: 22.8 W Size: W149xD188xH160

2010 2012 2014 2015 2016 2011 2013 2017

Project started PDR CDR Launch End of operation

BBM model Mass: 6.2 kg, Power: 39.5 W Size: W65xD114xH138

PFM model

Experiments Checkout SOTA

Workshop

6


Major Specifications of SOTA

SOTA-OPT

Photograph and Layout of SOTA-PFM optics (Proto Flight Model)

Mass 5.9 kg (incl. both the optical

part & electric part)

Power consumption

Sleep mode

Stand-by

Tx1 Tx2,3,

4

1.7W 2.0W 15.7W 12.6W

Gimbal range Az: >±50deg,

El: -22deg~+78deg

Link range Less than1000 km

Wavelength

Tx1: 976 nm

Tx2 and Tx3 : 0.8 μm

Tx4 : 1549 nm

Rx: 1064 nm, Acquisition/Tracking: 1064 nm

Data Rate 1Mbps / 10Mbps (selectable)

7


Small Satellite “SOCRATES” Satellite bus developed by AES

Mass : 48kg

© AES

Size W496 x D495 x H485 mm

Solar Paddle

SOTA

Attitude control : 3-axis stabilization 8


Optical Ground Station in Koganei (1-m Diameter)

- 1-m diameter reflective telescope - Improved tracking ability for LEO satellites - Focus availability: 5 ports (Cassegrain, Nasmyth, Coude…)

Koganei

Major specification Mount Altazimuth Focus Classical Cassegrain Diameter f1000 mm D/f F12 Tracking accuracy LEOs < 10 arcsec Stars < 0.4 arcsec (EL > 30 deg.) Stars < 1 arcsec (EL=15~30 deg.)

Angle coverage Azimuth ±270 deg. Elevation 15~88 deg. Total mass 7.5 t Tube mass 1.3 t Nasmyth payload mass 1 t (max)

9


Launch 24th of May, 2014

Piggyback satellite of the ALOS-2 “DAICHI-2”

Orbit : Sun-synchronous sub-recurrent orbit

http://h2a.mhi.co.jp/mission/results/index.html

Altitude : 628km

Advanced Land Observing Satellite

10

http://h2a.mhi.co.jp/mission/results/index.html


11

Small satellite bus

Small Optical TrAnsponder

(SOTA)

Optical ground station (OGS)

(NICT Koganei)

TT&C station 5) Telemetry data

Small camera

Small satellite system

Data & control signals

Image data & control

Ground system

TT&C

Direct Comm.

*TT&C: Tracking, Telemetry and Control

4) Tx laser

2) Commands

- Configuration of SOTA Experiment - 1)

Par

amet

ers

6) T

elem

etry

3) Beacon laser


Date Event

May 24, 2014 SOCRATES Launch

~ July Check out of the satellite

~ Oct. Check out of the OGS and the SOTA

Nov. ~ Experiments for the NICT

May, 2015 ~ Start of international experiment campaign

Spring, 2016 ~ Resumption of international experiment campaign

Schedule of Conducted Experiments

12


Statistics of Total 184 Passes Both Uplink – Downlink Established 47 passes

Failed (due to OGS) 30 passes

Failed (due to Satellite) 17 passes

Only Uplink Established 21 passes

38 %

Bad Weather Forecast

26%

21%

Go

No Go

62 %

Satellite Trouble 2 passes

67 passes

13


Success Criteria

14

No. Experiment items Contents Status Minimum success

M1 Start-up check of equipment Demonstration of COTS parts Done

M2 Confirmation of optical sensors etc. Demonstration of COTS parts Done

Success

S1 Tracking test Confirmation of orbit, bus attitude control and mounted equipment Done

S2 Propagation data acquisition

Acquisition of the received signal, data acquisition at different wavelengths (Uplink: 1064nm / Downlink: TX1, TX4)

Done

S3 BER measurement Downlink: TX1, TX4 Done Full success

F1 Data transmission experiment

Confirmation of data transmission functions ( Data: CAM / PRBS / Sample image ) ( Downlink: TX1, TX4) Done

F2 Error correcting code LDGM and RS codes Done Extra success

E1 Polarization measurement

Weak coherent pulses are measured by single photon counting detectors (SPCMs). Done

E2 International experiment Experiment with other international optical ground stations (OGSs) except for Koganei OGS. Done


Site-Diversity Technology Weather-monitoring stations Whole-sky monitor camera

http://sstg.nict.go.jp

Optical communication satellite

OGS

Laser beam

OGS control center

Cloud

15

http://sstg.nict.go.jp


Optical Ground Stations Network

Koganei 1.5m

Koganei 1m

Kashima 1m Okinawa 1m 16


Overview of In-orbit Experimental Results with SOTA

• Overview of the SOTA project • NICT’s New OGS • In-orbit performance of SOTA • Atmospheric-turbulence analysis • BER measurement • Data-transmission experiment • Error-correcting code experiment • QKD-related experiments • LEO-satellite optical observation with NICT

portable telescope • Optical detection for SOTA downlink experiment

using SSPD • International joint-experiment campaign

17


Summary (1) Space-to-ground laser-communication experiments with the SOTA terminal have been successfully conducted. (2) Almost all of the success criteria from minimum- to extra-success have been done, including international experiments. (3) World first lasercomm technology for a 50-kg-class micro-satellite was verified with several international partners globally, which has opened the door to a variety of applications to be exploited soon with the rise of mega-constellations.

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Documents

Overview of the Small Optical TrAnsponder (SOTA) …...One of the smallest optical-communication terminals for spacecraft equipment SOCRATES衛星に 組み込まれた Mass : 6.2

Overview of the Small Optical TrAnsponder (SOTA) …...One of the smallest optical-communication terminals for spacecraft equipment SOCRATES衛星に組み込まれた Mass : 6.2