Inversion of PROSPECT-5
S. Jacquemoud
November 27, 2014
IPGP, Sorbonne Paris Cité, Université Paris Diderot, UMR CNRS 7154, 35-39 rue Hélène Brion, 75013 Paris, France
Upper epidermis
Lower epidermis
Palisade parenchyma
Spongy parenchyma
transmitted + emitted
ab
sorb
ed
reflected + emitted
Leaf optical properties
1R T A
s dR R R
A
Sinclair et al. (1973), Agronomy Journal, 65:276-283.
Leaf optical properties in the solar domain
VIS PIR MIR
Clover (Trifolium pratense)
Transmittance
Reflectance
http://opticleaf.ipgp.fr/
n, k
N la
yers
T
R
1 la
yer
Monocots
Dicots
MONOCOTS
DICOTS
Plate model
Multi-layer model
Allen et al. (1969), Journal of the Optical Society of America, 59:1376-1379. Stokes (1862), Proceedings of the Royal Society of London, 11:545-556.
PROSPECT: principle
6
Direct mode
PROSPECT-5
Inverse mode
Leaf reflectance
and/or transmittance INPUT PARAMETERS
Leaf structure parameter N Chlorophyll content Cab ( g/cm2) Carotenoid content Ccx ( g/cm2)
Brown pigments Cbp (r.u.) Equivalent water thickness Cw (cm)
Dry matter content Cdm (g/cm2)
OPTICAL CONSTANTS Refractive index
Specific absorption coefficients
Jacquemoud & Baret (1990), Remote Sensing of Environment, 34:75-91.
PROSPECT: direct versus inverse mode
Féret et al. (2008), Remote Sensing of Environment, 112:3030-3043.
PROSPECT-4: one-factor-at-a-time sensitivity analysis
N = 1.5, Cab = 50 g.cm 2, Cm = 0.005 g.cm 2
PROSPECT-4: global sensitivity analysis
Contribution to leaf transmittance
Cab Cw
Cm
N
http://teledetection.ipgp.fr/prosail/
Download the Matlab files at: http://teledetection.ipgp.fr/prosail/PROSPECT5_Matlab_inversion.rar
dataSpec_P5B.m
complex refractive index
tav.m
Fresnel's equations
invleafP5B.m
main program
fminsearch('chi2P5B',P0,[ ],rmes,tmes)
leaf reflectance (rmes) and/or
transmittance (tmes)
chi2P5B.m
merit function
LRT=prospect_5B(N,Cab,Ccx,Cbp,Cw,Cdm)
chi2=sqrt(sum((rmes-LRT(:,2)).^2+(tmes-LRT(:,3)).^2))
prospect_5B.m
leaf optical properties model
LRT=prospect_5B(N,Cab,Ccx,Cbp,Cw,Cdm)
Retrieved parameters
N,Cab,Ccx,Cbp,Cw,Cdm
PROSPECT: inverse mode
Measured parameters
Cab,Ccx,Cw,Cdm
Validation
Experiment
Model optimization
PROSPECT: leaf reflectance/transmittance reconstruction
Poplar (Liriodendron tulipifera)
400 600 800 1000 1200 1400 1600 1800 2000 2200 24000
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Wavelength (nm)
Re
fle
cta
nc
e T
ran
sm
itta
nc
e
N = 1.28 Cab
= 37.4 Ccx
= 7.14 Cbp
= 0.0 Cw
= 0.01169 Cdm
= 0.00500
R measured T measured R model T model
More than 1000 leaf samples corresponding to 15 independent datasets acquired over various
environmental conditions:
climate: temperate, tropical
ecosystem: forest, crops
more than 100 species
0 50 1000
20
40
60
80
100
MEASURED
RETRIEVED
CHLOROPHYLL
RMSE = 6.2111
0 5 10 15 20 250
5
10
15
20
25
MEASURED
RETRIEVED
CAROTENOIDS
RMSE = 3.2562
0 0.01 0.02 0.030
0.005
0.01
0.015
0.02
0.025
0.03
MEASURED
RETRIEVED
WATER
RMSE = 0.0025773
PROSPECT: leaf parameter retrieval
Féret et al. (2008), Remote Sensing of Environment, 112:3030-3043.