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Technique of CO2 concentration profile retrieving from satellite - - PowerPoint PPT Presentation
Technique of CO2 concentration profile retrieving from satellite - - PowerPoint PPT Presentation
Technique of CO2 concentration profile retrieving from satellite data by means of neural network approach Kataev M.Yu., Andreev A.G. Goals of work: To develop the scientific computer program for modeling GOSAT NIR spectrums and their
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The main trajectories of the solar beams in the system « earth + atmosphere ».
Green is the reflected from surface solar radiation Blue is the scattering in atmosphere solar radiation
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τ τΘ0
Θ0 1
I2(λ) τΘ0
1 2
rλ I1(λ) ρ(λ)
Reflected and scattering parts of the signal
atmosphere I1(λ) =E0τΘ0cos(Θ0)ρλτ
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Radiative transfer (RT)
(F-M. Breon, S. Boffies J.Appl.meteorol., 1996, Jan, pp. 69-76)
⎪ ⎭ ⎪ ⎬ ⎫ ⎪ ⎩ ⎪ ⎨ ⎧ + + − =
∫
2 1
)) , ( ) , ( ) , ( ( 1 exp ) , , , (
2 1 P P mol aer gas
dp p p p P P T λ α λ α λ α µ µ λ
) , , 1 , ( ) , , , ( ) ( ) ( ) (
1 surf surf sun surf
P T P T R S I λ µ λ λ π λ λ ⋅ = dp P p T P p T F p F p S I
surf surf sun P aer aer aer mol mol sun
surf
) , , 1 , ( ) , , , ( )) ( ) , ( ) ( ) , ( ( 1 ) ( ) (
2
λ µ λ γ λ α ψ γ λ α µ π λ λ ⋅ ⋅ + ⋅ =
∫
) cos( )] 1 )( 1 [( ) cos(
2 / 1
ϕ µ µ µ µ γ
sat sun sat sun
− − − − =
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Databases for spectra calculation in global world
l 1 Solar spectra, Kurucz spectral resolution 1 cm-1, l 2 Spectroscopic information HITRAN2004 spectral
parameters database,
l 3 Meteorological parameters – NCEP Reanalysis
data 6 hours 2.5x2.5 grad,
l 4 Gases concentration profiles H2O – NCEP data,
CO2 – NIES (S.Maksyutov) data
l 5 Aerosol extinction – SPRINTARS (Toshihiko
Takemura,RIAM,Kyushu Univ.)
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Variations of the CO2 concentration profile for West Siberia region
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Data from NCEP with comparison
- f AFGL climatological model
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Example of transmittance calculation for Channel 2 of GOSAT
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SEARCH OF THE OPTIMAL SPECTRAL CHANNELS
⎥ ⎦ ⎤ ⎢ ⎣ ⎡ − ⋅ ⋅ = ) , ( ) , ( 1 ) , ( ) , ( 1 ) , , (
1 2 2 1 2 1
µ ν µ ν µ ν µ ν σ µ ν ν
- T
T T T L
where - dispersion of the measurements, - transmittance for all components of air besides gas under investigation, - transmittance (1 – lie in absorption lines of gas under investigation and 2 – very small absorption of gas under investigation).
) , (
2 , 1
µ ν
- T
σ ) , (
2 , 1
µ ν T
6040 6042 6044 6046 6048 6050 6052 6054 6056 6058 6060 0.0 0.2 0.4 0.6 0.8 1.0
ON OFF CH4 All
Transmittance Wavenumber, cm-1
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Results of searching of the CO2 spectral channels
The 753 wavenumber with help of algorithm when selection criterion for retrieving error =0.1% was found.
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Clusterization of the CO2 data
The clusterization is based on close structure analysis of matrix of the distances between objects. The algorithm is realized using of performance of graph theory.
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Neural network approach for inverse task solving
) ( ) (
1
∑
=
+ = =
n i i i
w x w f g f y
Mathematical model of the neuron
y
w1 w2 wn
n
w0
∑
f(g) x1 x2 xn a1x1 a2x2 anxn
The neural network of one layer; f(g) is the activation function; inputs: х1, х2, ..., хn; weight factors: w11, w12, …,
- utputs: y
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Scheme of Neural network in our work
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Maximal relative error on training of NN for retrieving of the CO2 concentration profile
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Resuls of retrieving of the CO2 concentration profile from test samples (A) and training samples (B).
A B
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Relative error of CO2 concentration profile retrieving with changes of the aerosol optical thickness
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l Technique of CO2 concentration profile
retrieving from satellite data by means of neural network approach Kataev M.Yu., Andreev A.G.
Tomsk state university of control systems and radioelectronics
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