The result of the initial functional verification on-orbit...

Barcelona, Spain, 7-11 September 2009 -1-

Atmospheric Science ConferenceThe result of the initial functional verification

on-orbit of GOSAT10 September, 2009@Barcelona, Spain

Masakatsu Nakajima, Akihiko Kuze, Hiroshi Suto, Kei Shiomi, Shuji Kawakami and Takashi Hamazaki

GOSAT Project TeamJapan Aerospace Exploration Agency

GGreenhouse gases reenhouse gases OObserving bserving SATSATelliteellite

10 September 2009ESA ASC 2009 2

Program OverviewProgram Overview

GOSATGGreenhousereenhouse gasesgases OObservingbserving SATSATelliteellite..

Nickname = Nickname = ““IBUKI””

ToTo monitor the global distribution of Greenmonitor the global distribution of Green House House GasesGases ((GHGGHG’’ss), especially, the CO), especially, the CO2 2 and theand the CHCH44..--with relative accuracy of 1% for COwith relative accuracy of 1% for CO22 and 2% for CHand 2% for CH44

To reduce subTo reduce sub--continental scale COcontinental scale CO22 annual flux annual flux estimation estimation erroserros by halfby half-- 0.54GtC/yr to 0.27GtC/Yr0.54GtC/yr to 0.27GtC/Yr

(C)NIES



OrganizationOrganization

GOSAT is the joint project of JAXA, MOE (Ministry of Environment) and NIES (National Institute for Environmental Studies).

•Sensor development •Satellite development•H-IIA launch •Satellite operation•Data acquisition•Calibration

•Algorithms development•Data use for science •Validation

JAXAMOE

NIES Satellite:

Mission Instruments:

TANSO onboard GOSAT TANSO onboard GOSAT TANSO=TANSO=TThermal hermal AAnd nd NNear ear

infrared infrared SSensor for ensor for carbon carbon OObservationbservation

Size Main body

3.7 m x 1.8 m x 2.0 m（Wing Span 13.7m）

Mass Total 1750kg

Power Total 3.8 KW (EOL)

Life Time 5 years

sun synchronous orbit

Local time 13:00+/-0:15

Altitude 666km

Inclination 98deg

Orbit

Repeat 3 days

Vehicle H-IIALaunch

Schedule Jan. 23 2009

TANSOTANSO--CAICAI(Cloud and Aerosol (Cloud and Aerosol Imager)Imager)Ultraviolet (UV) (0.38 micron), Ultraviolet (UV) (0.38 micron), visible (0.67 micron), NIR (0.87 visible (0.67 micron), NIR (0.87 micron), and SWIR (1.6 micron)micron), and SWIR (1.6 micron)

TANSOTANSO--FTSFTS(Fourier Transform (Fourier Transform Spectrometer)Spectrometer)SWIR reflected on the SWIR reflected on the earthearth’’s surfaces surface--TIR radiated from the TIR radiated from the ground and the ground and the atmosphereatmosphere



Spectral Coverage and Absorption LinesSpectral Coverage and Absorption Lines

GOSAT Spectral Coverage

0

50

100

150

200

250

0 3 6 9 12 15Wavelength (micron)

Spe

ctra

l Rad

ianc

e（W

/str/

m2/

mic

ron ）

Band 4

Band 2

0

10

20

1.57 1.62 1.67

Band 1

0

50

100

0.758 0.763 0.768 0.773

Band 3

0

5

10

1.98 2.03 2.08

CO2O2 CH4

CO2

O3CH4

CO2

Column density of CO2 is mainly retrieved by using the absorption lines between 1.6micron (Band 2) region.

The intensities of these lines are less temperature dependent and not interfered by other molecules.O2 A band absorption at 0.76 micron are used to estimate the effective optical path length.

3 narrow bands0.76micron1.6micron and2micron

A wide band5.5 – 14.3 micron

With 0.2cm-1 spectral resolution



Day Side: 1 pm orbit

EastWest

Equator

TANSO-CAI

Sun Glint

Cloud and Aerosol Scattering>>S

STANSO-FTSPolarization Bands

P

North

South

IMC ID=5

TANSO-FTS

Camera

Camera FOV > 30 kmTANSO FTS IFOV=10.5 kmTANSO CAI IFOV=0.5, 1.5 km

SWATH 900km

Pointing and FootprintsPointing and Footprints

Cross Track

X km Y km

1 789 903 263 2835 158 1527 113 1159 88 86

@Log.&Lat. 30deg

cross track patters



Nominal ObservationNominal Observation Target & Sun glint ObservationTarget & Sun glint Observation

Scan PatternsScan Patterns



OperationOperation

FTS SWIR & TIRCAI

Solar Flux

FTS TIR

Solar Irradiance Cal.Lunar Cal

Special observation mode: FTS-Diagnostic Mode,Viewing the diffused LD light during a few orbit.

Day sideNight side



GOSAT Data ProductsGOSAT Data Products

Level 4 Processing - estimate the net flux

Level 4 Processing - estimate the net flux

NIES L1 Data

MeasurementMeasurement

Receive and RecordReceive and Record

Interferogram

JAXA

0.000

0.005

0.010

0.015

0.020

5200 5400 5600 5800 6000 6200 6400Wavenumber (cm-1)

Rel

ativ

e va

lue

H2O CH4 CO2H2O CO2CH4

L2 Data

Data distribution

Data distribution

Level 2 and 3Processing- to produce the global distribution map for

CO2 and CH4- validation

Level 2 and 3Processing- to produce the global distribution map for

CO2 and CH4- validation

（ｃ）NIES（ｃ）NIES

Level 1 processing- processing to spectra- calibration

Level 1 processing- processing to spectra- calibration



TIR non-linearity correction

ZPD detection, ZPD shift, DC subtraction (B2,B3)

I-FFT SPC (for Low Freq. Cal.)

Raw IGM (SWIR #76336 TIR #38168) (Level-1A）

I-FFT Partial data.& Phase Cal.

I-FFT for fine step

Wave number Corrected SPC.

(Level-1B)

FCE Correction for fine ZPD

Low Frequency Correction.(IFOV instability, jitter)

Zero-filled IGM (#76545)

SWIR

Apply DS’s ZPD

TIR (DS)

TIR (BB, Obs.)

I-FFT Complex

I-FFT Complex

Phase Cor. SPC

SPC (BB, Obs)

SPC (DS)

TIR

Level 1A Data and Processing for Level 1A Data and Processing for FTSFTS

IGM(V) (Spike detection.&correction)

(Level-1B)

Bobs(ν) = Sobs− SDS

SBB − SDS

BBBeffective


NO. TANSO-FTS TANSO-CAI

1 First and Second Light IFOV and FOV

2 Observation bands Data acquisition period

3 Signal to Noise Ratio Gain and Dynamic Range

4 Spectral Resolution (Instrument function) Signal to Noise Ratio

5 FOV MTF

6 Scan Pattern Sensitivity Deviation among Pixels

7 Gain and Dynamic Range Registration between bands

8 micro vibration Lunar Calibration

9 Diffuser Stray light

10 Stability of the wavelength Transient Response

11 Stability of the Sensitivity Temperature Control

12 Pointing accuracy

13 Turn Around and count of the fringe

14 Stray light

15 Sun glint observation

16 Temperature control

17 Calibration accuracy

InitialInitial Functional Verification Functional Verification of TANSOof TANSO--FTS and CAI FTS and CAI



Successfully detected from space at Visible (760nm) and SWIR(1.6, 2.0um) with High resolution.

0.0030

0.0020

0.0010

0.0000Inte

nsity

[V/c

m-1

]

135001340013300132001310013000129001280012700Wavenumber [cm- 1]

0.0016

0.0012

0.0008

0.0004

0.0000Inte

nsity

[V/c

m-1

]

6700660065006400630062006100600059005800570056005500

0.0016

0.0012

0.0008

0.0004

0.0000Inte

nsity

[V/c

m-1

]

550054005300520051005000490048004700

B3P B3S

B2P B2S

B1P B1S

FTS First LightFTS First Light



CAI First LightCAI First Light



Monitor Camera (moon rise and tracking)

Lunar Calibration Lunar Calibration

B1P B2P

B3P

March 11,2009- Solar flux reflected on Lunar was stably detected.



Estimated SNREstimated SNR

Band On Orbit Ground

B1P 369 345B1S 243 247B2P 322 322B2S 270 258B3P 463 412B3S 315 287B4 304 298

Methods-SWIR

Applied 50 Lunar CalibrationAssumptionsAlbedo: Band1: 0.13, Band2&3: 0.2

-TIRApplied 50 Deep space and Blackbody

No significant degradation of the optical and modulation efficiency.

0.012

0.010

0.008

0.006

0.004

0.002

0.000

Inte

nsity

[a.u

.]

200018001600140012001000800600Wavenumber [cm- 1]

500

400

300

200

100

0

SNR

SigDS SigBB SigBBDS SNR



note1: non-correction of the spectralon Diffuser BRDFnote2: non-correction of Doppler shift

0.0E+00

1.0E-06

2.0E-06

3.0E-06

4.0E-06

5.0E-06

6.0E-06

7.0E-06

8.0E-06

6170 6175 6180 6185 6190 6195 6200

Irrad

ianc

e (W

/cm

2/cm

-1)

Wavenumber (cm-1)

Modtran

Solar Irradiance (March 4)(front) 2P

Smithsonian Kurucz (2009)

Solar Irradiance Solar Irradiance



-0.2

0.0

0.2

0.4

0.6

0.8

1.0

6457 6458 6459 6460 6461 6462 6463

Nor

mal

ized

Wavenumber (cm-1)

March 12, 2009 ILS Calibration with the onboard Diode Laser

Inflight March 12, 2009Model

FWHM=0.268cm-1

Line Shape FunctionLine Shape Function

Optical miss-alignment is not found.



Ghost signal is related with Earth Sensor Head of 244Hz.

Ghost signal level is lower than 1/1000 of true signal.Negligible!

Micro Vibration EffectMicro Vibration Effect


CAI images around JapanBAND-1

H

M

Over the desert, the integration time was switched from middle(M) to High(H) and it was confirmed that the ratio of the high gain to middle gain is similar to the design and appropriate.

The dynamic range was not confirmed quantitatively in the initial functional verification because there is not the source whose radiance is known.The dynamic range will be confirmed quantitatively in the calibration and validation phase.

BAND-2 BAND-3 BAND-4

average(DN)bandgain H gain M

H/M design

1 1101.8 659.5 1.67 1.682 2876.4 2086.4 1.38 1.413 2671.2 1628.7 1.64 1.68

L 3370.1 1993.9 1.69 1.684M 3302.1 1639.7 2.01 2.00

CAI Gain and Dynamic RangeCAI Gain and Dynamic Range



April 8, 2009 over Japan, band 1 (380nm) and band 3 (870nm)

Very low surface albedo at band 1 and suitable for aerosol and thin cloud detection

CAI data (UV CAI data (UV -- SWIR images)SWIR images)



SummarySummary

GOSAT was successfully launched at 23. Jan. 2009.

TANSO-FTS and CAI data acquisition was started from Feb.7 ,and the initial performance and functional test in orbit have been carried out.

GOSAT is operated regularly, and Level 1 data has been provided to NIES and RA users.

Now operating regularly



AcknowledgementAcknowledgement

Thank you!Thank you!

GOSAT Project MembersGOSAT Project Members

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