Scientific Application Using
GOSAT DATA – Calibration
Japan Aerospace Exploration Agency
Kei Shiomi

Workshop on Data Utilization of GOSAT “IBUKI”,Toranomon Pastral Hotel, 5 November, 2008

Research proposals on calibration
 “Characterization of micro vibration effect to spaceborneFTS on orbit”
 Suto, Kuze, Seki, Nakamura(JAXA) “Lunar calibration of TANSO using SELENE spectral
profiler data”
 Matsunaga(NIES), Ohtake, Haruyama(JAXA), Tsuchida, Nakamura,Kodama(AIST), Iawasaki(Univ. Tokyo), Saeki(Osaka Univ.)

 “GOSAT infrared FTS validation and CO2 retrievals”

 Strow, Hannon, Imbiriba(Univ. Maryland Baltimore Country)

 “Radiometric and spectral assessment of GOSAT TIR
observations”
 Knuteson, Revercomb, Tobin(Univ. Wisconsin-Madison)

Characterization of micro vibration
effect to spaceborne-FTS on orbit (1/2)
 Purposes
 Assessment of resistance to micro-vibration
 Assessment of methodology of on-orbit evaluation of
micro-vibration effect Assessment of methodology of pre-flight estimation of
sensor environment

 Ghost signals come from
 Changing of modulation efficiency
 Sampling jitter IFOV jitter ILS laser multiple measurements
 Good SNR (>5000) appropriate for investigation ofmicro-vibration effect
Dr. Suto’s research proposal

Characterization of micro vibration
effect to spaceborne-FTS on orbit (2/2)

 (Top) Investigation of micro-vibration effect using TSUKUBA airborne
simulator of TANSO-FTS (Bottom) Simulated 90Hz micro-vibration effect superimposed on thespectrum
Dr. Suto’s research proposalLunar calibration of TANSO using
SELENE spectral profiler data (1/2)
 Purposes
 Absolute radiometric calibration of FTS and CAI using
lunar observation except CAI Band1 0.38 micron Spectral Profiler on SELENE(KAGUYA) Lunar global reflectance dataset in nearside producedby
 Observation from Nov. 2007 to Mar. 2009
 0.5-2.6 micron by resolution of 6-8 nm
 500 m footprint Photometric function applied to UV-NIR region

Dr. Matsunaga’s research proposalLunar calibration of TANSO using
SELENE spectral profiler data (2/2)
600 nm1680 nmNorthSatelliteFlightDirection

SP Transect
Width ≈ 500 mSouth© JAXA/SELENE© JAXA/SELENE

950 nmSpectral ProfilerEarth-based
Telescope (Top) SP first light on
Dec. 14, 2007
 (Bottom) Comparison
between SP andearth-based telescopeobservation

19 km

FTS

Mare Serenitatis 2CAIMareSerenitatis
D?707 km

Tycho

Tycho
CraterD?85 km

0.5

1.0

1.5
Wavelength [µm]2.0Ｍatsunaga, et al., Geophys. Res. Lett., doi:10.1029/2008GL035868, in press.

Dr. Matsunaga’s research proposal

GOSAT infrared FTS validation andCO2 retrievals (1/2)
Purposes
Radiometric and spectral calibration using
ECMWF and sonde data
CO2 retrieval from TANSO-FTS TIR by theapplication of AIRS and IASI method
Cross validation of CO2 of GOSAT and AIRSor IASI

Currently, TIR CO2 is studied from
Aqua/AIRS from 2002
MetOp/IASI from 2006
Dr. Strow’s research proposal

GOSAT infrared FTS validation andCO2 retrievals (2/2)

 (Left) Preliminary result of Longwave CO2 retrieval fromAIRS in Apr. 2004
 (Right) Cross validation of radiances between AIRS andIASI relative to ECMWF
Dr. Strow’s research proposal

Radiometric and spectral assessmentof GOSAT TIR observations (1/2)
 Purposes
 Evaluation of the onboard calibration performance for various scenetypes
 Validation of L1B radiances against forward model calculations atground truth sites (ARM/ Lamont, Barrow, Darwin)
 Validation of the L1B radiances using aircraft (S-HIS) and/or satellite
sensors (AIRS,IASI) Application of Univ. Wisconsin atmospheric state retrieval algorithms
to the GOSAT FTS L1B radiances in order to translate calibration
errors into sounding errors

 ARM site
 AERI, sonde, and a lot of instruments for atmospheric parameters Fly of Scanning High-resolution Interferometer Sounder as possible

Dr. Tobin’s (for Knuteson) research proposal

Radiometric and spectral assessmentof GOSAT TIR observations (2/2)

 Validation of IASI spectral radiance observations using
S-HIS and NAST-I data collected on 19 April 2007 over
the Oklahoma ARM site.
 IASI has excellent absolute and spectral calibration
accuracy relative to the Univ. Wisconsin S-HIS.
Dr. Tobin’s (for Knuteson) research proposalSummary GOSAT calibrations will be studied by Micro-vibration effect investigation using ILS calibration
 Lunar calibration using SELENE SP data
 Radiance comparison between GOSAT TIR andIASI/AIRS CO2 retrieval comparison between GOSAT TIR and IASIor AIRS Radiance comparison at ARM sites with sonde andairborne sensor S-HIS Atmospheric retrieval comparison between GOSAT TIRand ARM site measurement