get.reflectances

get.reflectances propagates the thin-layer reflectance and transmittance factors of the canopy (computed by the SAIL 4-stream radiative transfer scheme) down through all nl canopy layers to the soil, and back up, to obtain the directional-hemispherical and hemispherical-hemispherical reflectance at the top of each layer.

Usage

get.reflectances(tau_ss, tau_sd, tau_dd, rho_dd, rho_sd, rsoil, nl, nwl = 2162)

Arguments

tau_ss

numeric matrix with nl rows and nwl columns. Direct-direct transmittance of each thin canopy layer.

tau_sd

numeric matrix with nl rows and nwl columns. Direct-diffuse transmittance of each thin canopy layer.

tau_dd

numeric matrix with nl rows and nwl columns. Diffuse-diffuse transmittance of each thin canopy layer.

rho_dd

numeric matrix with nl rows and nwl columns. Diffuse-diffuse reflectance of each thin canopy layer.

rho_sd

numeric matrix with nl rows and nwl columns. Direct-diffuse reflectance of each thin canopy layer.

rsoil

numeric vector of length nwl. Soil reflectance spectrum at the bottom boundary.

nl

integer. Number of canopy layers.

nwl

integer. Number of wavelengths in the spectral domain (default 2162, i.e. 400-2500 nm plus the thermal region).

Value

A list with:

R_sd

numeric matrix with nl+1 rows and nwl columns. Directional-hemispherical reflectance at the top of each layer (including the soil, layer nl+1).

R_dd

numeric matrix with nl+1 rows and nwl columns. Hemispherical-hemispherical reflectance at the top of each layer (including the soil, layer nl+1).

Xss

numeric vector of length nl. Direct-direct transmittance of each layer (identical to tau_ss, kept for use in flux propagation).

Xsd

numeric matrix with nl rows and nwl columns. Normalized direct-to-diffuse transmittance of each layer, accounting for multiple reflections with the layers below.

Xdd

numeric matrix with nl rows and nwl columns. Normalized diffuse-to-diffuse transmittance of each layer, accounting for multiple reflections with the layers below.

Author

 Wout Verhoef, Christiaan van der Tol, Joris Timmermans (Original version in Matlab)

Carlos Camino (Ported version into R)

Examples

if (FALSE) { # \dontrun{
refl <- get.reflectances(tau_ss, tau_sd, tau_dd, rho_dd, rho_sd, rsoil, nl, nwl = 2162)
} # }