satellite: convRad2Ref – R documentation

Become an expert in R — Interactive courses, Cheat Sheets, certificates and more!

convRad2Ref

Convert a band's scaled counts or radiance values to reflectance

Description

Convert a band's scaled counts to reflectance using a simple linear conversion without any kind of atmospheric correction etc.

Usage

## S4 method for signature 'Satellite'
convRad2Ref(x, szen_correction = "TRUE")

## S4 method for signature 'RasterStack'
convRad2Ref(x, mult, add, szen)

## S4 method for signature 'RasterLayer'
convRad2Ref(x, mult, add, szen)

Arguments

`x`	An object of class Satellite, raster::RasterStack or raster::RasterLayer providing radiance values.
`szen_correction`	Logical; if `TRUE`, sun zenith correction is being applied.
`mult`	Multiplicative coefficient for value transformation (i.e. slope).
`add`	Additive coefficient for value transformation (i.e. offset)
`szen`	Cosine of solar zenith angle.

Details

The conversion functions are taken from USGS' Landsat 8 Data Users Handbook which is available online at https://www.usgs.gov/land-resources/nli/landsat/landsat-8-data-users-handbook.

If the sensor does not provide linear conversion coefficients for reflectance computation, the reflectance is calculated using the solar irradiance following the functions taken from USGS' Landsat 7 manual, chapter 11.3.2, which is available online at https://landsat.gsfc.nasa.gov/wp-content/uploads/2016/08/Landsat7_Handbook.pdf.

Value

If x is a Satellite object, a Satellite object with added converted layers;
if x is a raster::Raster* object, a raster::Raster* object with converted layer(s).

Examples

path <- system.file("extdata", package = "satellite")
files <- list.files(path, pattern = glob2rx("LC08*.TIF"), full.names = TRUE)
sat <- satellite(files)  
sat <- convRad2Ref(sat)

# If you use a raster layer, supply required meta information
bcde <- "B002n"
convRad2Ref(x = getSatDataLayer(sat, bcde),
            mult = getSatRADM(sat, bcde),
            add = getSatRADA(sat, bcde))

satellite

Handling and Manipulating Remote Sensing Data

v1.0.2

MIT + file LICENSE

Authors

Thomas Nauss, Hanna Meyer, Tim Appelhans, Florian Detsch

Initial release

2019-12-06