Inversion of PROSPECT-5

S. Jacquemoud

(jacquemoud@ipgp.fr)

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.