Instrument design, on Instrument design, on- -orbit performance, orbit performance, calibration, and level 1 data processing of calibration, and level 1 data processing of lib lib ti ti d l d l l 1 d t l 1 d t i i f f TANSO TANSO FTS on GOSAT TANSO-FTS on GOSAT TANSO FTS on GOSAT FTS on GOSAT March 17, 2010 March 17, 2010 Akihiko KUZE Akihiko KUZE CIMSS SSEC CIMSS SSEC University of Wisconsin, University of Wisconsin, Madison Madison
Contents Contents (1) GOSAT (1) GOSAT- -project overview project overview (2) TANSO instrumentation (2) TANSO instrumentation (3) On (3) On- -orbit Performance orbit Performance ( ) ( ) (4) Data (4) Data Processing Processing and instrument model g and instrument model (5) (5) TIR data (5) (5) TIR data TIR data TIR data
TANSO status The Greenhouse gases Observing SATellite (GOSAT) observes carbon dioxide (CO2) and methane (CH4) globally from space. It was launched on January 23, 2009 from Tanegashima Space Center. Since February 7, 2009, the Thermal And Near infrared Sensor for carbon Observation Fourier Transform Spectrometer (TANSO FTS) and Cloud Sensor for carbon Observation Fourier-Transform Spectrometer (TANSO-FTS) and Cloud and Aerosol Imager (TANSO-CAI) have been continuously operated. They acquire global data every three days. The brief summary of instrument design, pre-launch test results, observation plan (grid and sun glint observation and special target mode), onboard calibrations, and the initial on-orbit results of radiometric, geometric and spectroscopic performances are presented performances are presented. TANSO-FTS Level 1A and 1B data processing algorithm and TANSO FTS Level 1A and 1B data processing algorithm and its updates on the ground are also presented. In addition we will show recent on-orbit instrument status such as pointing accuracy, interferogram quality, and radiometric accuracy and vicarious calibration results. Especially TANSO-FTS band 4 (thermal infrared band) performance and calibration will be discussed in detail. March, 2010, Madison, Wisconsin 3
GOSAT GOSAT GOSAT GOSAT P P Project Overview Project Overview j j j j t O t O i i
Mission Targets Mission Targets Greenhouse gases reenhouse gases O Observing bserving SAT SATellite. ellite. Nickname = “ Nickname = “IBUKI” (Breath in Japanese) Nickname Nickname IBUKI (Breath in Japanese) ” (Breath in Japanese) (Breath in Japanese) ( ) (1) To observe CO 2 and CH 4 column density y 2 4 - at -1000km spatial scale (with scanning mechanical) - with relative accuracy of 1% for CO 2 (4ppmv, 3 months average) (target 1ppmV) and 2% for CH 4 . (t t 1 V) d 2% f CH - during the Kyoto Protocol's first commitment period (2008 to 2012). (2) To reduce sub-continental scale CO 2 annual flux estimation errors by half -0.54GtC/yr → 0.27GtC/yr March, 2010, Madison, Wisconsin 5
GHG Observing Points g Ground Stations Ground Stations From Space (Now) From Space (Now) （By WMO WDCGG） ・ Over 56,000 points per 3days •337 ground stations in the world. (L1 data, L2 before screening) •The number of stations is limited The number of stations is limited, ・Global and frequent observation and they exists unevenly in the with an single instrument world. March, 2010, Madison, Wisconsin 6
Organization g ORGANIZATION GOSAT is the joint project of JAXA, MOE (Ministry of the Environment) and NIES (National Institute for Environmental Studies) NIES (National Institute for Environmental Studies). MOE JAXA •Sensor development •Satellite development •H-IIA launch H IIA launch •Satellite operation •Data acquisition •Calibration •Algorithms development •Algorithms development NIES •Data use for science •Validation March, 2010, Madison, Wisconsin 7
Launch Vehicle Size Size Main body Main body 3 7m(H) x1 8m(W) x 2 0m(D) 3.7m(H) x1.8m(W) x 2.0m(D) (Except attachment) Wing Span 13.7 m Mass Total 1,750 kg Power Total 3.8KW(EOL) Life Span Life Span 5 years 5 years Orbit Sun Synchronous Orbit Local time Local time 13:00+/-0:15 (12:47 March 2009) 13:00 / 0:15 (12:47 March 2009) Altitude 666 km Inclination 98 deg Re-visit 3 days Launch Vehicle H-IIA Date Jan. 23, 2009 March, 2010, Madison, Wisconsin 8
Satellite Configuration g Thermal And Near infrared Sensor for carbon Observation TANSO FTS TANSO-FTS TANSO-CAI SWIR/TIR FTS SWIR/TIR FTS UV, Visible, SWIR Imager March, 2010, Madison, Wisconsin 9
TANSO-FTS Spectral Coverage p g GOSAT Spectral Coverage 250 � 3 narrow bands � 3 narrow bands Band 1 Band 2 � 0.76 μ m 20 100 200 � 1.6 μ m 10 50 CO 2 CH 4 O 2 � 2.0 μ m on ） nce 0 0 tr/m2/micro � A � A wide band id b d ctral Radian 0.758 0 758 0 763 0.763 0 768 0.768 0 773 0.773 1.57 1 57 1.62 1 62 1 67 1.67 150 � 5.5 – 14.3 μ m Band 3 CO 2 � With 0.2cm -1 spectral 10 100 100 resolution (interval) l ti (i t l) Spec 5 （ W/s 0 1.98 2.03 2.08 CO 2 50 O 3 CH 4 CH 4 Band 4 0 0 3 6 9 12 15 Wavelength (micron) Wavelength (micron) � Column averaged density of CO 2 is mainly retrieved by using the absorption lines between 1.6 μ m region. � The intensities of these lines are less temperature dependent and not interfered by other molecules. � O A band absorption at 0 76 μ m estimate the effective optical path length � O 2 A band absorption at 0.76 μ m estimate the effective optical path length. March, 2010, Madison, Wisconsin 10
Radiative Transfer and Parameters to be observed Parameters to be observed FTS covers wide spectral range Stratospheric aerosol Cloud GHG Tropospheric aerosol Earth’s surface High spectral resolution data of (1) Solar lines (2) Earth albedo (reflectance and scattering) (3) Thermal radiation (3) Thermal radiation (4) Two linear polarizations March, 2010, Madison, Wisconsin 11
TANSO TANSO TANSO TANSO Instrument Instrument Instrument Instrument
TANSO-FTS specification and performance ifi ti d f FOV FOV IFOV 10 5 k IFOV 10.5 km Coverage 790 km C 790 k Speed 1.1, 2, 4 sec/interferogram band band 1P, 1S 1P, 1S 2P, 2S 2P, 2S 3P, 3S 3P, 3S 4 4 12900- 5800- 4800- 700 Coverage (cm -1 ) 13200 6400 5200 -1800 Resolution (cm -1 ) 0.5 0.2 0.2 0.2 Detector Si InGaAs InGaAs PC-MCT SNR(prelaunch) SNR(prelaunch) >340 >340 >320 >320 >410 >410 >280 >280 (Measured ） Onboard Solar irradiance, Black body, C lib Calibration ti D Deep Space, S deep space d Lunar （ radiance ） (Radiance) Diode laser(ILS) March, 2010, Madison, Wisconsin 13
FTS Optics Layout p y Scene Deep Black Diffused flux space body solar from from view view view view flux fl Pointing and image nadir motion compensation CMOS Camera 1296 by 1040 pixels Redundant system Aperture stop (Cube (Cube Collecting mirror Corner) Field stop DF2 DF2 DF3 DF3 DF1 Collimating BPF3 BPF1 BPF2 mirror MCT(B4) on Dewar and Pulse Tube Cooler InGaAs with TE cooler (B3) P,S InGaAs with TE Si (B1)P,S cooler (B2) P,S March, 2010, Madison, Wisconsin 14
Pointing and footprints g p Mie Scattering Scattering P>>S Camera FOV > 30 km North TANSO FTS IFOV 10 5 k TANSO FTS IFOV=10.5 km TANSO CAI IFOV=0.5, 1.5 km TANSO-FTS SWATH 900km TANSO-CAI Camera IMC ID=5 Equator Sun glint P East East TANSO-FTS West West S S Polarization Dayside ： afternoon South March, 2010, Madison, Wisconsin
Observation Patterns Nominal Observation (Grid Observation) By adjusting turn-around-time onboard, TANSO-FTS revisit the same observation TANSO FTS revisit the same observation Special Target Special Target points every 3 days. Validation point , Mega City, Pipeline, Sun glint March, 2010, Madison, Wisconsin
Polarization Measurements Input: I, Q, U, V of Stokes Vector Input: I, Q, U, V of Stokes Vector Output: Two Linear Polarizations P S ( ( ) ) ( ( ) ) ( ( ) ) ( ( ) ) = − θ θ θ θ S M M M 2 M M M 2 S Poutput Poutput pp pp opt opt r r CT CT p p AT AT m m AT AT r r CT CT input input ( ) ( ) ( ) ( ) = − θ θ θ θ 2 2 S M M M M M M S Soutput ps opt r CT p AT m AT r CT input March, 2010, Madison, Wisconsin 17
TANSO-CAI Specification and Performance Specification and Performance Center Center SNR SNR Bandwidth Resolution band wavelength pixel Detector (Prelaunch) (nm) (IFOV) (km) ( μ m) (measured) 1 0.380 20 0.5 2000 Si >200 2 0.674 20 0.5 2000 Si >200 3 0.870 20 0.5 2000 Si >200 4 1.60 90 1.5 500 InGaAs >200 TANSO-CAI Band 4 Spectral Response TANSO-CAI Band 1 Spectral Response (Optics(with new filter) + Si CCD response) (Optics + InGaAs CMOS response) 1.0 1.0 0.8 0.8 d Normalized Normalized 0.6 0.6 0.4 0.4 0.2 0.2 0.0 0.0 350 360 370 380 390 400 410 1500 1550 1600 1650 1700 Wave length (nm) Wave length (nm) March, 2010, Madison, Wisconsin 18
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