topocorr_samp: Topographic correction for satellite imagery

In yinscapital/sat-locat-reference-team-lucc: TEAM land use and cover change data processing toolkit

Description

Perform topographic correction using a number of different methods. This code is modified from the code in the landsat package by Sarah Goslee. This version of the code has been altered from the landsat version to allow the option of using a sample of pixels for calculation of k in the Minnaert correction (useful when dealing with large images).

Usage

topocorr_samp(x, slope, aspect, sunelev, sunazimuth, method = "cosine",
  na.value = NA, IL.epsilon = 1e-06, sampleindices = NULL,
  DN_min = NULL, DN_max = NULL)

Arguments

x	image as a RasterLayer
slope	the slope in radians as a RasterLayer
aspect	the aspect in radians as a RasterLayer
sunelev	sun elevation in degrees
sunazimuth	sun azimuth in degrees
method	the method to use for the topographic correction: cosine, improvedcosine, minnaert, minslope, ccorrection, gamma, SCS, or illumination
na.value	the value used to code no data values
IL.epsilon	a small amount to add to calculated illumination values that are equal to zero to avoid division by zero resulting in Inf values
sampleindices	(optional) row-major indices of sample pixels to use in regression models used for some topographic correction methods (like Minnaert). Useful when handling very large images. See gridsample for one method of calculating these indices.
DN_min	minimum allowable pixel value after correction (values less than DN_min are set to NA)
DN_max	maximum allowable pixel value after correction (values less than DN_max are set to NA)

Details

See the help page for topocorr in the landsat package for details on the parameters.

Value

RasterBrick with two layers: 'slope' and 'aspect'

Author(s)

Sarah Goslee and Alex Zvoleff

References

Sarah Goslee. Analyzing Remote Sensing Data in R: The landsat Package. Journal of Statistical Software, 2011, 43:4, pg 1–25. http://www.jstatsoft.org/v43/i04/

Examples

#TODO: add examples

yinscapital/sat-locat-reference-team-lucc documentation built on May 14, 2019, 11:09 a.m.