The development status of Second
Generation Global Imager (SGLI),Infrared Scanning Radiometer (IRS)
October 14, 2014
SPIE Asia-Pacific, Beijing
Kazuhiro TANAKAGCOM project/JAXA

http://suzaku.eorc.jaxa.jp/GCOM_C/index_j.html

Contents
 GCOM mission and GCOM-C satellite Current Status
 The development status and key

components performance of Infrared
Scanning Radiometer (IRS) Conclusion

The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing

2

Global Change Observation Mission(GCOM) Global observation satellite system as JAXA’s GEOSS contribution.
 2 satellite series for 5 years, total 13 years observation.

 GCOM-W
Microwave
radiometricobservation
for
WATER CYCLE using AMSR2 (AMSR-E follow on)
 GCOM-C Optical multi-channel observation for RADIATIONBUDGET and CARBON CYCLE using SGLI (GLI follow on)
GCOM-C(CLIMATE)

GCOM-W(WATER)AMSR2GCOM-W “SHIZUKU”
was launched on May 18,
2012.

SensorAdvanced Microwave Radiometer 2(AMSR2)
Passive Microwave Observation
Water vapor, soil moisture etc

The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing

GCOM-Cis scheduled for launchin JFY2016.

Sensor

SGLISecond Generation Global Imager(SGLI)
Optical Observation 380nm – 12 micron
Cloud, Aerosol, Vegetation, Chrolophl etc3

Second generation Global Imager (SGLI)
on GCOM-C satellite
SGLI VNR
ELU

SGLI IRS
ELU+Y
deep
space

+X
flightdirection+ Z earth

SGLI VNR
SRU

SGLI IRS
SRU
Mission Life> 5 years

Solar Paddle> 4000w （End of Life）

Mass

about 2,000kg

The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing

SGLI
VNR
IRS
SRU
ELU

Second Generation Global Imager
Visible and Near Infrared Radiometer
Infrared Scanning Radiometer
Scanning Radiometer Unit
Electronic Unit4

Current Status

Critical Design Review (CDR) of SGLI sensor andGCOM-C satellite was held in 2013.
 The flight model (PFM) manufacturing wasapproved.
The manufacturing of SGLI key flight parts, such asoptics, filters, detectors or coolers, is almost finishedand under the final inspection for the components
assembly and tests.
SRU sensor system integration and test is ongoing
until early 2015. The sensor level pre-flight tests will
be done in 2015.
Satellite level test will start in 2015 and planned forlaunch in JFY 2016.

The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing

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SGLI Performance• The SGLI features are 250m (VNR-NP, SW3 & TIR) spatial resolution andpolarization/along-track slant view channels (VNR-PL), which will
improve land, coastal, and aerosol observations.
GCOM-C SGLI characteristics
Sun-synchronousOrbit(descending local time: 10:30)
Altitude 798km, Inclination 98.6deg
Mission Life 5 years (3 satellites; total 13 years)
Push-broom electric scan (VNR)
Scan
Wisk-broom mechanical scan (IRS)
1150km cross track (VNR: VN & P)
Scan width
1400km cross track (IRS: SW & T)
Digitalization 12bit
Multi-angle
Polarization 3 polarization angles for Pobs. for674nm andAlong track Nadir for VN, SW and T,
869nm
direction+45 deg and -45 deg for P

On-board
calibration

VN: Solar diffuser, LED, Lunar cal
maneuvers, and dark current bymasked pixels and nighttime obs.
SW: Solar diffuser, LED, Lunar, and darkcurrent by deep space window
T: Black body and dark current by deep
space window

The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing

250m over the Land or coastal
area, and 1km over offshore
SGLI channels
LstdLmax
IFOVNP,PL,SWI:
NP, PL, SWI:CH NP, PL, SWI: nm
SNR at Lstd
W/m2/sr/mm
T: m
T: NET
T: Kelvin
VN13801060210250
250
VN2412
1075
250
400
250
VN34431064400
300
250
VN44901053120400
250
VN55302041350250
250
VN6565203390400
250
VN7673.5202362400
250
VN8673.52025210250
250
250/1000
VN9763
12403501200
VN10 868.5
20830400
250
VN11 868.5
2030300
200
250
PL1673.52025250250
1000
PL2868.52030300
250
1000
SW110502057248500
1000
SW21380
208103150
1000
SW31630
200
35057
250
SW42210
50
1.9
20
211
1000
T1
10.8
0.7
300
340
0.2
250/1000
T2
12.0
0.7
300
340
0.2
250/1000
TIR : 500m resolution is also used.

6

Infrared Scanning Radiometer(SGLI-IRS)
Earth

Flightdirection
1.4m

Engineering model of SGLI-IRS
for vibration test configuration

OBS Light

0.6m

SWI-DET

SCAN
MOTOR

OpticalBench

SterlingCoolerBLACK
BODY

Weight: 193kg
Power: 400W

TIR-DET
The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing

7IRS scanning mirror
Reflectance [%]45deg tilting folding octagonal mirror.
Mirror is coated aluminum with above 84% reflectance andpolarization ratio is less than 1.4% including the telescopeand SWI-BPF effects.
The effect of mechanical stress to the mirror flatness isalso considered with the light weight requirement (1.1kg).
100

1009595909085858080

Reflectance [%]757075
70

No.165

No.260605555501.0

1.5

2.0

Scanning
Mirror (flight model)

No.1

65

No.2

2.5

[micron]The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing

50
10111213[micron]8

IRS scanning mechanism
 Geometric accuracy req. is 0.5 pixel of 250m.
 High rotation stability and measurement accuracy.
 AC servo motor with slot less type to avoid the torquedisturbance.
 The low surface pressure bearing with the high reliability
lubrication.

25000

Resolver Calibration Accuracy

16000
14000

20000

σ=0.02pixel

1σ=0.07pixel

12000

15000

Histgram

10000

10000
8000
6000400050002000

The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing

0.300

0.225

0.150

0.075

0.000

-0.075-0.150

0.147

0.124

0.101

0.078

0.054

0.031

0.008

-0.016-0.039-0.062-0.085-0.109-0.132-0.155[250m pixel]-0.22500-0.300Histgram

Scanning Mechanism(flight model)

Control Error

250m pixel

9

IRS telescope Ritchey-chretien type coated aluminum telescope.

(F/2.64, f=448mm, 170mm aperture) The several optical shields optimized to prevent theundesired stray light path.
 Thermally controlled within narrow room temperature
range for 5 years operation
 The minimum depth of focus is tested with MTF 60%requirement.
OBS LightFPA

Scan Mirror
The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing

IRS telescope

IRS telescope(Flight Model)

10

SWI focal plane assembly (SWI-DET) InGaAs type SWI PD array with 4band BPF.
 The detector array is cooled at -30deg using peltier

electronic cooler with PI control circuit in order to reducethe dark signal of 2.2micron channel.
 TIA circuit designed for low noise readout.
 AR coated window and filled with Xeon gas.
SWI
4Band Filters

Window
4BAND
FILTER

4BAND PD
ARRAY

FlightModel
The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing

PeltierCooler

11

TIR focal plane assembly (TIR-DET)
 PV type MCT detector with cold BPF in the LWIRD filledwith Neon gas.
 Cooler assembly with cryogenic dewar for the 55+/-0.1K
with PI controlled heater.
FlightCryogenic
ModelDewar 140micron (250m) big pixel output using
28micron small pixel summation.
Cold Head Commandable selection table for poor
performance sub-pixel deselection.

A-MUX

ADD

FlightModelCompressor

Long Wave Infrared
Detector (LWIRD)

Cooler Assembly

ADD

250m(140micron)x 20 pixels

BalancerVideo Signal

Selection Table

The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing

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IRS spectral performance
700

Total Response [mA/W]

600

300
200

100
0950

1000

1050

1100

500
400
300
200
100
01300

1150

1350

[nm]

0.8
0.6
0.4
0.209500

1500

TIR-1

10000

10500
[nm]

11000

11500

12000

11500
[nm]

12000

12500

13000

1.2

1000
900

800

600
500
400
300
200

100

1SW4
Normalized spectral response

SW3

Total Response [mA/W]

Total Response [mA/W]

1450

[nm]

700

700
600
500400300
20010001450 1500 1550 1600 1650 1700 1750 1800[nm]

SW1SW2SW3SW4T1T21400

1100

900
800

1SW2
Normalized spectral response

SW1400Total Response [mA/W]

1.2

800

500

02100

2150

2200
[nm]

2250

2300

2350

TIR-2

0.8
0.6
0.4
0.2010500

11000

FWHM Spectral Reponse [nm]Weighted Spectal Response
CenterPeakLower Half Response
Upper Half Responseband widthCenterHalf Responceband width
Wavelength Wavelength Wavelength10-80%
Wavelength10-80%
WavelengthLower
Heigherwidth
width
Wavelength Wavelength1054.91054.01044.411.1
1065.511.2
21.1
1054.91043.91065.721.71385.31387.01375.37.2
1395.47.6
20.1
1385.41375.01395.620.6
1633.71667.01536.219.4
1731.219.5
195.0
1634.51539.21730.2191.0
2210.62207.02185.418.2
2235.816.7
50.4
2210.72184.82236.551.7
10782.710840.010415.0197.911150.4
195.8
735.3
10786.1
10420.011157.1
737.1
11974.811790.011582.0
264.612367.5289.0
785.5
11956.7
11559.1
12327.9768.8

The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing

SGLI-N-TD-14119_0930_SGLI SWI 総合波長特性[第4版].xlsx
SGLI-N-TD-14238_0909_SGLI TIR 総合波長特性[第2版].xlsx

13Black Body Black body is used for thermal channels

calibration on-orbit with cold space response.
 The sensor background signal is canceled in two
points calibration techniques. The emissivity ofblack body is better than 98%.
Earth Observation

Diffused
Solar LightDeep SpaceSCAN
MIRRORLightGuide

BLACK BODY
OPTICAL BENCHBLACK BODY
(Flight Model)

2 points calibration for TIR and SWI
The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing

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LED-Halogen light assembly LED-Halogen light assembly is used to monitor the sensor

output between pre-flight calibration and on-orbit.
 Relative spectral shape is only checked with halogen lamp
output. The absolute response comparison is by 1.6micron
LED output in SW3 channel.
 SWI calibration activity is planned for every 8 days on orbit.
Calibration maneuver such as lunar calibration and solarbeta angle dependency check is also planned on orbit for thereliable calibration.
1.0

Halogen
8.0V
10.0V
12.0V

0.9

SWI LED assembly

SWI LED PD
assembly

The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing

Relative response

0.8

SWI Halogen
assembly

9.0V
11.0V

0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.01000

1200

1400

1600 1800
[nm]

2000

2200

2400

15IRS integration and tests
 IRS flight model sensor integration activity is ongoing.
 All components and panels are thermally baked before

integration under thermal vacuum conditions to prevent
outgas effects to IRS optical system.
 Optical bench with key optical components is located in
the middle of SRU baseplate.
 Integration activity is planned
IRS-SRU
in 2014 autumn period, andPreflight Test (PFT) including
Colimeter
optical performance check
starts at the end of 2014.
Rotation Stage

The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing

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Summary SGLI flight model manufacturing is ongoing.

 Key IRS flight component test results arepresented.
 Sensor integration & test will be started within
this year.
 Target launch of GCOM-C is JFY2016.

The development status of SGLI-IRS, Oct 14, 2014, SPIE Beijing17