get.Pso function

get.Pso calculates the bi-directional gap probability Pso, i.e. the joint probability of a sunlit and simultaneously viewed leaf (or soil background) at a given normalized canopy depth, accounting for the hot-spot effect between the solar and viewing directions.

Usage

get.Pso(K, k, LAI, q, dso, xl)

Arguments

K

numeric value. Canopy extinction coefficient in the direction of the observer.

k

numeric value. Canopy extinction coefficient in the direction of the sun.

LAI

numeric value. Total (one-sided) leaf area index of the canopy (m2 m-2).

q

numeric value. Hot-spot size parameter (leaf width to canopy height ratio, dimensionless).

dso

numeric value. Normalized distance between the sun and observer beams at the canopy level, derived from the solar/viewing zenith and relative azimuth angles (dimensionless).

xl

numeric value. Normalized cumulative canopy depth at which Pso is evaluated (dimensionless, 0 at the top of the canopy to -1 at the bottom, expressed as a fraction of LAI).

Value

numeric value. Bi-directional gap probability Pso at depth xl (dimensionless, 0-1).

Author

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

Carlos Camino (Ported version into R)

Examples

if (FALSE) { # \dontrun{
pso <- get.Pso(K, k, LAI, q, dso, xl)
} # }