Download presentation

Presentation is loading. Please wait.

Published byDeirdre Matthews Modified over 2 years ago

1
Overview of PROSPECT and SAIL Model 2nd IR/Microwave emissivity group meeting NOAA/NESDIS/STAR 2008.08.01 Bo Qian bqian@umd.edu

2
Introduction of PROSPECT PROSPECT is a radiative transfer model that represents the optical properties of plant leaves from 400 nm to 2500 nm. The key parameters in the model are leaf structure parameter (N), chlorophyll a+b (Cab) and the equivalent water thickness (Cw).

3
transmitted + emitted absorbed PROSPECT- Leaf Optical Properties Spectra MODEL reflected + emitted S.Jacquemoud and F.Baret, REMOTE SENS. ENVIRON.34:75-91(1990) depend on anatomical leaf structure and biochemical leaf composition

4
Description of the PROSPECT model N identical layers IsIs Elementary layer: n : refractive index K : global absorption coefficient Surface effects Hemispheric fluxes Global absorption: Specific absorption coefficients Content in absorbing material reflectance ( ) ( ) transmittance (A.Olioso, S.Jacquemoud,F.Baret, Adaptation of the leaf optical property model PROSPECT to thermal infrared, 2006)

5
N leaf structure parameter C ab chlorophyll a+b concentration ( g.cm 2 ) C bp brown pigment concentration ( g.cm 2 ) C w equivalent water thickness (cm) C m dry matter content (g.cm 2 ) PROSPECT INPUTS PROSPECT OUTPUTS R( ) T ( ) – leaf reflectance – leaf transmittance

6
Comparison of two different version 1998 version3.01 1995 version 2.01 Cw=0 Cw=0.002

7
PROSPECT V3.01 outputs under Cw from 0.0 to 0.02 cm -1 (0.0,0.0002, 0.0011, 0.0065, 0.0155, 0.02 cm -1 ) 0.0 0.02 N = 1.5, C ab = 50 g.cm 2, C dm = 0.005 g.cm 2 0.02 0.0

8
Energy balance Kirchhoff’s Law The emissivity of a body equals its absorptivity at thermal equilibrium So, absorptivity = emissivity ??? One question ?

9
Sensitivity of the Leaf Structure Parameter N N=1~1.5 Albino maize leaf and monocotyledons with compact mesophyll N=1.5~2.5 Dicotyledons by a spongy parenchyma with air cavities on the abaxial face N>2.5 Senescent leaves with a disorganized internal structure

10
Cw=0, N=1.0,1.5,2.0,2.5,3.0 3.0 2.5 2.0 1.5 1.0 Visible light Region

11
Cw=0.02, N=1.0,1.5,2.0,2.5,3.0 3.0 2.5 2.0 1.5 1.0 400,690,1450,1950,2500

12
reasonable Non-reasonable In fact, N=3,represents senescent leaves with disorganized structure, the Cw should be small even it is zero. So the combination given parameters of Cw=0.02 and N=3 should be non-reasonable. Relatively, the Cw=0.0 and N=3 will be a better choice.

13
Questions: The key point is how to determine the value of the combination inputs parameters. What is the relationships between inputs parameters realistically? (N, Cab, Cw,Cm,Cbp) Need in-situ data and satellites data validation

14
Scattering by Arbitrarily Inclined Leaves-SAIL Model

15
Introduction The scattering and extinction coefficients of SAIL model are derived for the case of arbitrary leaf inclination angle and a random leaf azimuth distribution. SAIL Model includes the G.H.Suits uniform model.

16
Canopy Layer Morphology Characteristics The idealized morphology of a canopy layer assumed for the SAIL Model is given as following: The layer is horizontal and infinitely extended The only canopy components are small and flat leaves The layer is homogenous

17
bi-directional reflectance directional-hemispherical reflectance soil surface plant canopy SAIL model (Verhoef 1984-1985) sun absorption of directional incoming radiation

18
SAIL Model parameters LAI mean leaf angle (θ l ) leaf reflectance (ρ l ) leaf transmittance (τ l ) soil reflectance (ρ s ) geometry of observation Sun position spectral reflectances absorption of solar radiation Inputs Outputs

19
W.VERHOEF, (1984),Remote sensing of Environment,16:15-141 Bidirectional reflectance profiles in the green(550nm) SAIL Model Suits Model H=1.000 V=1.571

20
W.VERHOEF, (1984),Remote sensing of Environment,16:15-141 Bidirectional reflectance profiles in the near infrared SAIL Model Suits Model H=1.000 V=1.571

21
Conclusions The SAIL Model is an improved version of Suits’s canopy reflectance model The extinction and scattering coefficients in the Suits’s Model are calculated on the basis of a given LAI and leaf inclination distribution The calculation of canopy reflectance is the same both models, the uniform Suits model is included as a special case

22
Next to do As a very important aspect is try to understand how to exactly determine the inputs parameters for these two models Understand the optical parameters calculation and details theory in the model

Similar presentations

OK

Quick Review of Remote Sensing Basic Theory Paolo Antonelli SSEC University of Wisconsin-Madison Monteponi, September 2008.

Quick Review of Remote Sensing Basic Theory Paolo Antonelli SSEC University of Wisconsin-Madison Monteponi, September 2008.

© 2018 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on acid-base titration equation Ppt on object-oriented concepts in php Ppt on e-sales order processing system Ppt on tsunami warning system to mobile Ppt on business etiquettes training programs Maths ppt on rational numbers Ppt on media and entertainment industry Ppt on classical economics school Ppt on cmos image sensor Ppt on x-ray tube