r_foursail {ccrtm}R Documentation

R implementation of foursail (pure R)

Description

The pure R version of foursail is included in the package as an easy way to review the code, and to check more optimized versions against. Model originally developed by Wout Verhoef.

Usage

r_foursail(rho, tau, bgr, param)

Arguments

rho

input leaf reflectance from 400-2500nm (can be measured or modeled)

tau

input leaf transmittance from 400-2500nm (can be measured or modeled)

bgr

background reflectance. Usual input is soil reflectance spectra from 400-2500nm (can be measured or modeled)

param

A named vector of SAIL parameter values (note: program ignores case):

  • [1] = Leaf angle distribution function parameter a (LIDFa)

  • [2] = Leaf angle distribution function parameter b (LIDFb)

  • [3] = Leaf angle distribution function type (see ?lidfFun)

  • [4] = Leaf area index (LAI)

  • [5] = Hot spot effect parameter (hspot) - The foliage hot spot size parameter is equal to the ratio of the correlation length of leaf projections in the horizontal plane and the canopy height (Verhoef & Bach 2007).

  • [6] = Solar zenith angle (tts)

  • [7] = Observer zenith angle (tto)

  • [8] = Sun-sensor azimuth angle (psi)

Value

spectra matrixwith 4 reflectance factors and canopy transmission for wavelengths 400 to 2500nm:

Author(s)

Marco D. Visser (R implementation)


[Package ccrtm version 0.1.6 Index]