topocorr_samp: Topographic correction for satellite imagery

Description Usage Arguments Details Value Author(s) References Examples

View source: R/topocorr_samp.R

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

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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

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#TODO: add examples

azvoleff/teamlucc documentation built on June 4, 2017, 12:08 a.m.