Workshop on the Data Utilization of GOSAT “IBUKI”,
Toranomon, Tokyo, November 5, 2008

Objectives of GOSAT
and the Data Application「いぶき」(GOSAT)の目的とデータ利用

Tatsuya Yokota

横田達也

NIES GOSAT Project Leader
Center for Global Environmental Research (CGER)
National Institute for Environmental Studies (NIES), Japan

Contents 報告内容
Background of the GOSAT project 背景Satellite remote sensing特徴Project objectives

目的

Data processing flow

処理の流れ



Data levels and products レベルとプロダクトGOSAT data utilization plan データ利用計画

5-Nov-08

Plan of the project use

プロジェクト内部利用Utilization by RA research

研究公募による利用1Background of measurement
requirement 背景Observed increase in global average temperature since mid-20th century
Í(very likely due to) increase in anthropogenic GHG concentration inthe atmosphere (IPCC Fourth Assessment Report (2007))
Imperative to balanceInsufficient knowledge (lack of understanding) ofthe emission due to human activities andthe absorption by the nature (land ecosystem, ocean, …)
for stabilizing the climate for the future
Absorption mechanisms of the land ecosystem and ocean
Climatological feedback in the carbon cycle involving atmosphere, land
ecosystem, and ocean
Î substantial part of the uncertainty in predicting future climate change

Needs of global, uniform, and frequent observation of CO2 and CH4

Spatial distribution and temporal variation
Î Carbon flux (source/sink) estimation Î attainment of adequate scientificknowledge on the underlying mechanisms

5-Nov-082

Satellite Remote Sensing ofGHGs 衛星観測の特徴
Satellite remote sensing of the atmosphere
Advantages:
Globally (uniformly) Unique sensors Î detectable relative differences Frequently repeat observation

Weak points:
Absolute value measurement of physicalparameters Several disturbances (error sources)

5-Nov-08(ex. Clouds, aerosols, precipitation, ground surface, …)

3

Status of ground measurements ofGHGs 温室効果ガスの地上観測の現状
(GHG monitoring stations: 282, CO2 measurement: 182)

(ｂｙＷＤＣＧＧ）
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4

Measurement locations oｆGOSAT
観測位置

3 days, 44 orbits recurrent orbit.
1 observation / 4 sec

Monthly mean (July) CO2 concentration along GOSAT orbit, with global offset subtracted
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5Example of GOSAT monthly map (Level 3)
GOSATの月別二酸化炭素観測マップのイメージ

5-Nov-08

6

GOSAT contribution to carbon flux
estimation
GOSAT（launch planned in 2008）
GHG Observations

Solar Radiation

Altitude
666 kmEstimation of Global
Carbon Flux Distribution

IFOV: 10 km φ
To apply the observational data fromGOSAT and ground-based data to an
inverse model to give global distributionof carbon sources and sinks
5-Nov-08●before 1991
●after 1992

Ground Monitoring Stations 7

Images of monthly carbon flux map(Level 4A) 炭素吸収排出量マップ例（February ２月）（August, ８月）←Absorption 吸収 [gC/m2/day] emission 排出→←Absorption 吸収 [gC/m2/day] emission 排出→Integrate scientific knowledge of carbon cycle including land and ocean→ Advancing carbon cycle models → Increase precision of climate change projection models→ Detailed study on determining cutback levels of emissions, (contribution to politicaldecision making)
陸域・海域を含む炭素循環に係る科学的知見の蓄積→ 炭素循環モデルの高度化 → 気候変動予測モデルの予測精度の向上→ 長期的には排出削減レベルの精緻化 （合理的な温暖化対策の立案への貢献）
5-Nov-08

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Project Objectives (1)「いぶき」の目的 (1)

To measure the global distribution of GHG concentrations (i.e. CO2and CH4) and its temporal variation
温室効果ガスの全球の濃度分布とその時間的変動を測定
To increase the accuracy of the flux (source and sink) estimation of
GHGs on the sub-continent scale (a few thousand kilometer square),
亜大陸レベルでの吸収排出量の推定精度を高める

5-Nov-08

Æ contributing to the sustention and development of systemized
observation in accordance with the Kyoto Protocol, while at the sametime facilitating the environmental administration efforts, including
ascertainment of the flux per region and evaluation of the carbon
balance in forests during the first period (2008-2012) as specified bythe Protocol.
→京都議定書に基づく組織的観測の維持及び開発の促進に貢献するとともに、京都議定書第1約束期間(2008～2012年）における地域ごとの吸収排出量の把握や森林炭素収支の評価等の環境行政に貢献する。
9Project Objectives (2)「いぶき」の目的 (2)The Project is intended to develop GHG
measurement technologies and othertechnologies necessary for future earthobserving satellites, by standing on and furtherevolving the existing earth-observing
technologies.
これまでの地球観測技術を継承・発展させ、温室効果ガスの測定技術を開発するとともに、将来の地球観測衛星に必要な技術開発を行う。

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Organizational Structureof GOSAT Project

The first GHGs observing satellite sensormission promoted by JAXA, MOE, and NIES.

MOE

Ministry of the Environment

Data user, policy,validation

NIES

National Institute forEnvironmental Studies

JAXA

Japan Aerospace Exploration
AgencyRocket launch, Satellite& Sensor development,
Data acquisition,
Calibration, L1 dataprocessing

Data processing algorithms, Scientific data use,
L2, L3 data processing and distribution, Validation
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Outline of GOSAT data processing
L1A
L 1B
Interferogram

L2 (column abundance
obtained by each scan)
L1
L3（spatial andtemporal average ofcolumnabundances）

2008/11/05

L4B

L4A

Source: NIES GOSAT pamphlet12

GOSAT Data Products (L1 & L2)
Processinglevel
L1A
L1B
L1B+Sensor/band

5-Nov-08

Category

Unit

FTS

FTS L1A data

Internal

FTS sceneCAI

CAI L1A data

Internal

CAI sceneFTS

FTS L1B data

Standard

FTS sceneCAI

CAI L1B data

Standard

CAI

CAI L1B+ data

Standard

L2 CO2 column amount (SWIR)

Standard

L2 CH4 column amount (SWIR)

Standard

L2 H2O column amount (SWIR)

Research

L2 CO2 profile (TIR)Standard

L2 CH4 profie (TIR)Standard

L2 CO2 column amount (TIR)

Research

L2 CH4 column amount (TIR)

Research

L2 temperature profile (TIR)

Research

L2 H2O profile (TIR)

Research

L2 H2O column amount (TIR)

Research

L2 cloud flag

Standard

L2 aerosol property

ResearchFTS SWIR

L2Product NameFTS TIRCAI

CAI frame

Any(on-demand)

CAI frame

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GOSAT Data Products (L3 &L4)
Processing
level

Sensor/band
FTS SWIRFTS TIR

L3CAI

L4A

-

L4B
5-Nov-08-

Product Name

Category

L3 global CO2 distribution (SWIR)

Standard

L3 global CH4 distribution (SWIR)

Standard

L3 global CO2 distribution (TIR)Standard

L3 global CH4 distribution (TIR)Standard

L3 global radiance distribution (all pixels)

Standard

L3 global reflectance distribution (clearsky)

Standard

L3 global cloud property

Research

L3 global aerosol property

Research

L3 global NDVIStandard

L4A global CO2 flux

Standard

L4A global CH4 flux

Research

L4B global CH4 distribution

ResearchUnit

Global(monthlyaverage)

Global(every 3 days)
Global(monthlyaverage)
Lat. 30°× Lon.
60°
(every 15 days)
64 locations acrossthe globe(annually)
Global 2.5° mesh14(monthly)Data Utilization（Research Categories）
(1) Sensor calibration

校正(2) Data processing algorithms

ｱﾙｺﾞﾘｽﾞﾑ(3) Carbon flux estimation, atmospherictransport models
モデル(4) Data product validation

検証(5) Data application

応用

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Research Topics planned by
the GOSAT Project

Calibrationinterferogram Î spectra correction of the variation of the observation
sensors’ field of view,
 TANSO-FTS: instrument function calibration,
radiance calibration, etc.
 TNASO-CAI: radiometric calibration, geometriccorrection, calibration of the sensor sensitivity,etc.
5-Nov-08

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Research Topics planned by
the GOSAT Project

Data processing algorithms
Development of fast data processing
algorithms,
 Sunglint observation data processing methods
 Processing algorithms using polarized data Extract parameters from thermal-infrared data
 Evaluation of spectral parameters of gaseous
molecules and sunlight spectra, Combined use of short wavelength infrared
and thermal infrared data, etc.
5-Nov-08

17

Research Topics planned by
the GOSAT Project

Carbon flux estimation, atmospherictransport models
Development and refining of source inventory
databases Refining of atmospheric transport and land
ecosystem models, etc.
 Development of carbon flux estimation models
with high temporal/spatial resolution, etc

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Research Topics planned bythe GOSAT ProjectValidation


Before the launch
Ground-based high-resolution and by small-sized FTSs with airborne
in-situ instruments
 Evaluation of sunglint observation algorithms using airborne or
ground-based FTSs
 Development of validation methods based on data taken by LIDAR,
sky radiometers or other equipment for validating aerosol, etc.


After the launch
Acquisition and analytical validation of data taken at validation sites
on land and on ocean (including island and cape), Analytical validation of data taken by instruments on board private
aircraft Comparison with data taken by other satellites or computed bymodels, etc., for the purpose of validating the quality of data on theCO2 and CH4 column abundances, as well as validating the quality ofdata on vertical distributions of CO2 and CH4 concentrations to be
derived from the thermal-infrared data.
 Validation of CAI data products.
19


5-Nov-08

Research Topics planned bythe GOSAT ProjectData application


FTS:
Analysis of basic phenomena that have influence on
evaluation of the characteristics and quality of data such as
temporal/spatial variation of concentration distributions andcarbon balance distributions
 Possible advanced applications, such as detection of CH4 leakfrom pipelines and local high-volume exhaust due to forest
fires, possibility of observing atmospheric trace components,
such as N2O, CFC, etc., and so on.
CAI:
5-Nov-08

Generation and utilization of the global vegetation index map
based on the CAI data.

20Concluding Remarks
GOSAT data products are categorized inStandard products: open to the public after calibrationand validation
 Research products: open to the registered researches
for sensor calibration, data validation, algorithm
development/improvement, and scientific use
 Some research products would be upgraded as standard
products after confirming their reliabilityA part of the GOSAT data utilization will be done by
the project members, the science team members,
and collaborators under the data policy restriction.
 We expect wider utilization by the world-wide users
to contribute to many fields of the data applications.
 International collaborations are expected.
5-Nov-08

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