albedo_reflected: Calculates the mean albedo of surfaces surrounding each...

Description Usage Arguments Details Value Examples

View source: R/radiationtools.R

Description

albedo_reflected is used to calculate mean albedo of surfaces surrounding a location from which radiation is reflected.

Usage

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albedo_reflected(alb, e = extent(alb))

Arguments

alb

a raster object, two-dimensional array or matrix of surface albedo values (range 0 - 1) derived using albedo() or albedo_adjust().

e

an optional extent object indicating the geographic extent of alb.

Details

A small proportion of radiation received at any given location is in the form of reflected radiation, and this function permits the albedo of surrounding surfaces to be calculated. An inverse distance-weighting is applied (range 0 to 1). If alb is a raster object, then a raster object is returned and e can be determined from alb.

Value

a raster object, two-dimensional array or matrix of values representing the mean albedo of surfaces surrounding each pixel of a two-dimension albedo array (range 0 - 1).

Examples

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library(raster)
alb <- albedo(aerial_image[,,1], aerial_image[,,2], aerial_image[,,3],
              aerial_image[,,4])
alb <- alb[901:1000, 901:1000]
e <- extent(c(169900, 170000, 12900, 13000))
rt <-raster(e, res = 1)
r_alb <- albedo_reflected(alb, e)
par(mfrow = c(2, 1))
plot(if_raster(alb, rt), main = "Surface albedo", col= gray(0:255/255))
plot(if_raster(r_alb, rt), main = "Albedo of surrounding surfaces",
     col= gray(0:255/255))

ilyamaclean/microclima documentation built on Dec. 14, 2018, 3:10 p.m.