satellite (version 1.0.5)

calcDODN: Compile dark object DN for given sensor band

Description

The function estimates the DN value of a "dark object" which is used for atmospheric correction using the DOS2 and DOS4 model. Therefore, the frequency distribution of the smallest 1% of the data values is analyzed and the value for which the first derivate has the absolute maximum is taken as the DN for a dark object.

Usage

# S4 method for Satellite
calcDODN(x, bcde)
# S4 method for RasterLayer
calcDODN(x)

Value

Numeric value of the DN for the dark object.

Arguments

x

Satellite object or RasterLayer with sensor band data, e.g. returned by getSatDataLayer.

bcde

If 'x' is a Satellite object, a band code as character.

Details

The DN for a dark object is extracted from a histogram similar to Chavez (1988).

References

Chavez Jr PS (1988) An improved dark-object subtraction technique for atmospheric scattering correction of multispectral data. Remote Sensing of Environment 24/3, tools:::Rd_expr_doi("10.1016/0034-4257(88)90019-3").

See Also

The DN is used by calcPathRadDOS for computing the path radiance based on the dark object method.

Examples

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

calcDODN(sat, bcde = "B002n")
calcDODN(getSatDataLayer(sat, bcde = "B002n"))