skyl: Sky light model

In MarcoDVisser/ccrtm: Coupled Chain Radiative Transfer Models

Sky light model

Description

Simple skyl atmospheric model.

Usage

skyl(rddt, rsdt, rdot, rsot, Es, Ed, tts, skyl = NULL)

Arguments

rddt	Bi-hemispherical reflectance
rsdt	Directional-hemispherical reflectance for solar incident flux
rdot	Hemispherical-directional reflectance in viewing direction
rsot	Bi-directional reflectance factor
Es	Solar flux
Ed	Diffuse flux
tts	solar angle
skyl	diffuse fraction, if NULL skyl is estimated using the tts (solar angle).

Details

The version implemented here can also include a dependence of the sun zenith angle after Danner et al. (2019) who build on recommendations from Francois et al. (2002).

Value

a list with hemispherical and directional reflectance.

References

Francois, C., Ottle, C., Olioso, A., Prevot, L., Bruguier, N., Ducros, Y.(2002). Conversion of 400-1100 nm vegetation albedo measurements into total shortwave broadband albedo using a canopy radiative transfer model. Agronomie 22, 611-618.

Danner M, Berger K, Wocher M, Mauser W, Hank T. Fitted PROSAIL Parameterization of Leaf Inclinations, Water Content and Brown Pigment Content for Winter Wheat and Maize Canopies. Remote Sensing. 2019; 11(10):1150.

Examples

data(solar)
rt<-fRTM(rho~prospect5+foursail)
skyl(rt[,"rddt"],rt[,"rsdt"],rt[,"rdot"],rt[,"rsot"],
Es=solar[,1],Ed=solar[,2],tts=45,skyl=NULL)

MarcoDVisser/ccrtm documentation built on Feb. 19, 2025, 1:15 p.m.