Data Processing (1) データ処理手法 (1) Short Wavelength Infrared Bands of the TANSO-FTS 短波長赤外バンド

Transcription

1 Workshop on the Dt Utiliztion of GOSAT IBUKI, Tornomon, Tokyo, November 5, 2008 Dt Processing (1) データ処理手法 (1) Short Wvelength Infrred Bnds of the TANSO-FTS 短波長赤外バンド Ttsuy Yokot 横田達也 NIES GOSAT Project Leder Center for Globl Environmentl Reserch (CGER) Ntionl Institute for Environmentl Studies (NIES), Jpn

2 Contents 報告内容 Rditive Trnsfer Forwrd Model for the SWIR bnds 短波長赤外バンドで利用する放射伝達モデル DISORT-bsed nd HSTAR (Terry Nkjim) codes Solr Frunhofer lines --- Robert Kurucz s new dt 太陽フラウンホファー線情報 : Kurucz 博士の新データ Polriztion 偏光 Pstr2 code Dt filtering データの事前フィルタリング Dt Retrievl Method データ処理手法 Mimum A Posteriori (MAP) method MAP 法 Error sources nd strtegy 解析の誤差要因と取り扱い Aginst disturbnces of cirrus clouds nd erosols Two step method 巻雲とエアロゾルの扱い 2ステップ法 5-Nov-08 1

3 Observtionl Mode (TANSO-FTS) Pointing long the truck cross IFOV=10km the truck ( 陸上 直下 / 斜方視 ) Sun Glint Pointing Mode ( 海上 鏡面反射点 ) サングリント点 5-Nov-08 2

4 TANSO-CAI (L1A) CAI L1B Processing CAI L1B Met-files CAI L2 Cloud Judge TANSO-FTS- SWIR (L1B) 事前処理 Pre-processing 気象データ準備処理 Meteorologicl Dt Preprtion 大気輸送モデル計算結果準備処理 Atmospheric Trnsport Model Preprtion DEM (GTOPO30) 気象データ Meteorol. Dt (GPV) 大気輸送モデル計算結果 ATM Output 大気輸送モデル計算処理 Atmospheric T.M. Process. CAI L2 Cloud flg フィルタリング処理 Dt Filtering L2 processing of TANSO-FTS-SWIR (1) 1 エアロゾル輸送モデル計算結果 Aerosol TM Output エアロゾル輸送モデル計算 Aerosol T. M. Process. 5-Nov-08 (SPRINTARS) 3

5 1 CAI L1B 中間ファイル Interim Dt フィルタリング処理 Dt Filtering CAI L2 エアロゾル物理量算出 Aerosol Prmeter clc. CAI L2 エアロゾルパラメータ Aerosol Prmeter 先験値設定処理 Prior Setting カラム量算出処理 Column retrievl MODIS 地表面反射率 MODIS Ground Surfce Albedo Dt L2 processing of TANSO-FTS-SWIR (2) プロダクト作成処理 Products compiltion TANSO-FTS- SWIR (L2) 5-Nov-08 4

6 TANSO-FTS SWIR L2 Dt Processing 初期値 Initil 気温 気圧 T, P 地表面特性 Albedo ˆ = 0 ( 先験情報 ; prior) + Δ( 観測に基づく修正量 ; posterior) Algorithm アルゴリズム理論輝度スペクトル Synthesized 大気の状態 Atmosphere 放射伝達計算アルゴリズム ( 多重散乱, 偏光 ) Rditive Trnsfer Rdince (W/m 2 /micron/str) 6400cm cm 装置の特性 ILS 比較 Comp. スペクトル残差の重み付き二乗和が最小になるように未知パラメータ ( カラム濃度 ) を調整 繰り返し演算 6400cm cm Spectr Wvelength (micron) Wvelength (micron) Rdince (W/m 2 /micron/str) 観測輝度スペクトル Observed Spectr Itertion MAP method 5-Nov-08 5

7 Chnnel selection nd Solr Frunhofer lines During the nlyses of the field cmpign, we found the disgreement between the Frunhofer lines of the solr spectrum dtbse nd those of observed spectrum. The solr spectrum dtbse re updted, but chnnels overlpped with the Frunhofer lines re ecluded in the retrievl nlysis for sfety. (Anlyzed by Y. Yoshid (NIES)) 5-Nov-08 6

8 TANSO-FTS Configurtion Ground Pointing Mechnism nd Fore optics Fourier Trnsform Spectrometer Configurtion Scnning Field of view Speed Spectrl bnd 1P, 1S Coverge 0.75 µm µm 2-es scnner (fully redundnt) for pointing Cross Trck (+/- 35 deg) Along Trck (+/- 20 deg) IFOV <10.5 km 790 km (scn width) (ltitude of 30 deg) 0.25, 0.5, 1 (Interferogrm)/sec 2P, 2S 1.56 µm µm 3P, 3S 1.92 µm µm µm µm resolution (cm -1 ) Detector Si InGAs InGAs PC-MCT Clibrtion Solr Irrdince, Deep Spce, Moon, Diode Lser Blckbody, Deep spce 5-Nov-08 7

9 Incident light is devided by two polrized component by PBS. I Q U V To simulte the observed spectr, we hve to know I, Q, nd U of the incident light. MEASURED SPECTRA

10 Incident light is devided by two polrized component by PBS. Version 1 (Sclr I RT code) Reconstruct To simulte totl the intensity I Q from observed spectr, mesured spectr. we hve to know I, U Q, nd U of the incident light. V MEASURED SPECTRA

11 Incident light is devided by two polrized component by PBS. Version 2 (Vector RT code) Simulte To simulte mesured the spectr directly. observed spectr, we hve to know I, Q, nd U of the incident light. MEASURED SPECTRA

12 Rditive trnsfer model: Hstr nd Pstr2. High spectrl resolution version of the System for Trnsfer of Atmospheric Rdition (Hstr); [Nkjim et l.] Sclr rditive trnsfer (rdince clcultion only). Hybrid model: Discrete-ordinte / mtri-opertor (dding) method (Nkjim nd Tnk, 1986). Multilyer multiple scttering medi. The delt-m trunction method. Ect single scttering correction; TMS- nd IMS-method (Nkjim nd Tnk, 1988). Rough ocen surfce model (Nkjim nd Tnk, 1983) / Lmbert surfce. Direct multi-solr bem (for LUT clcultion). Arbitrry viewing geometry (Source function integrtion). Vector rditive trnsfer model (Pstr2). Sme s the bove rditive trnsfer scheme. Coupled tmosphere-ocen system including polriztion effect. 2008/11/05 11

13 Mesurement Dt Filtering CAI L1B CAI L2 Cloud Flg Aerosol Trnsport Model (SPRINTARS) Prllel Filtering Items ( 並行判定基準 ) Solr Zenith Angle <70 deg. 太陽天頂角判定 Surfce elevtion vribility 地表面凹凸判定 Diff. <25 m Cloud Msk Flg by CAI CAI 雲判定 < 1 picel Cloud Estim. from FTS-TIR TIR 雲判定 Aerosol t higher ltitudes 高高度エアロゾル判定 Scttering Prticles (cirrus) 2μm 帯散乱物質判定 Signl Sturtion Low intensity, 観測信号の飽和, 低輝度 Finl Judgment 総合判定 Filtering Results フィルタリング結果 5-Nov-08 12

14 5-Nov Opertionl Dt Retrievl Method Non-liner Lest squre fit of the spectr for both SWIR nd TIR dt Constrined Guss-Newton Method (Mimum A Posteriori method; MAP) SWIR bnds Column bundnces of CO 2 &CH 4 TIR bnd Volume miing rtio profiles of CO 2 ( ) ( ) ( ) ( ) [ ] i i T i i T i i i S F y S K S K S K + + = ε ε F(): Rdince Spectrum K = F()/ : Jcobin mtri ( ) ( ) [ ] ( ) [ ] ( ) ( ). min = T T S F y S F y J ε

15 Opertionl Dt Retrievl Method Non-liner Lest squre fit of the spectr for both SWIR nd TIR dt Constrined Guss-Newton Method (Mimum A Posteriori method; MAP) = + ( ) [ ( ( )) ( )] T T 1 1 K S K + S K S y F S i+ 1 i i ε i i ε J F(): Rdince Spectrum K = F()/ : Jcobin mtri T 1 T 1 ( ) = [ y F( ) ] S [ y F( ) ] + ( ) S ( ) min. ε mesurement SWIR bnds Column bundnces of CO 2 &CH 4 TIR bnd Volume miing rtio profiles of CO 2 i priori i 5-Nov-08 14

16 SWIR Dt Retrievl Method Simultneous retrievl of column-ghgs, surfce lbedo spectr 2), cirrus prmeters (height, opticl thickness), nd other liner fctor possibly cused by instrument clibrtion error CO 2 nd CH 4 re retrieved seprtely Non-liner Lest squre fit of the spectr Constrined Guss-Newton Method (Mimum A Posteriori method; MAP) Interim VMR profile retrievl Column bundnces X CO2,X CH4 (Alwys ssuming cirrus-eisting condition) 5-Nov-08 15

17 SWIR Dt Retrievl Method Simultneous retrievl of column-ghgs, surfce lbedo spectr 2), cirrus prmeters (height, opticl thickness), nd other liner fctor possibly cused by instrument clibrtion error CO 2 nd CH 4 re retrieved seprtely 6400cm Non-liner Lest squre cm fit of the spectr H Constrined Guss-Newton Method 2 O 2.0 (Mimum A Posteriori method; MAP) Rdince (W/m 2 /micron/str) 1.5 Interim VMR profile retrievl Column 1.0 CO 2 bundnces Xbsorption CO2,X CH 0.5 CH4 4 bsorption bnds bnd (Alwys ssuming cirrus-eisting condition) Wvelength (micron) 5-Nov-08 16

18 Dt retrievl simultion under cirrus-eisting condition ( 巻雲への対処手法 ) Retrievl of column-co 2, ground surfce lbedo, cirrus height, cirrus opticl thickness,

19 Reflection from cirrus/erosol cirrus erosols Cirrus effects will be cncelled with two-step estimtion method by using the H 2 O sturted spectrl region of the 2.0 µm bnd Some types of the erosols (e.g. including lrge prticles) will ffect serious error on the retrievl. We re now investigting wy to overcome the erosol effects. 5-Nov-08 18

20 Info. bout cirrus height nd OPD Step #1: The cirrus opticl depth (τ), the cirrus cloud center height (h), nd ground surfce lbedo (α 0.76, t 50 cm -1 intervls) t the 0.76 µm (O 2 -A) bnd re estimted from the 0.76 µm bnd nd the H 2 O sturted spectrl region of the 2.0 µm bnd OD=0.5 Step #2: Simultneous retrievl of column density of CO 2, ground surfce lbedo (α 1.6 t 50 cm -1 intervls), nd re-estimtion of τ from the 1.6 µm bnd cirrus Cirrus height (Ground surfce) 10 5-Nov-08 19

21 Concluding Remrks まとめ Key issues of the TANSO-FTS-SWIR processing: Dt Filtering & Retrievl フィルタリング と 導出処理 が要点 GOSAT rditive trnsfer (DISORT nd HSTAR bse) codes nd dt retrievl lgorithms (MAP method) will be improved yer by yer. Polrized dt utiliztion MAP 法 ( 非線形最小二乗法 ) により導出する 手法の改良も予定 偏光の取り扱いが重要 5-Nov-08 20