dn2toa {ASIP}

R Documentation

DN to TOA conversion of optical bands

Description

Digital number (DN) bands to Top of Atmosphere (TOA) conversion.

Usage

dn2toa(directory = getwd(), crop = "n", ext2crop = "none",
  op_directory = directory, b1 = 1, b2 = 1, b3 = 1, b4 = 1, b5 = 1,
  b6 = 1, b7 = 1)

Arguments

ext2crop, crop, directory	Same as mentioned in arvi.
op_directory	Specify the output directory (within double quotes). By default the input satellite image directory will be selected as the output directory.
b1	By default Band1 will be processed to TOA reflectance. To cancel production of this band assign value 0.
b2	By default Band2 will be processed to TOA reflectance. To cancel production of this band assign value 0.
b3	By default Band3 will be processed to TOA reflectance. To cancel production of this band assign value 0.
b4	By default Band4 will be processed to TOA reflectance. To cancel production of this band assign value 0.
b5	By default Band5 will be processed to TOA reflectance. To cancel production of this band assign value 0.
b6	By default Band6 will be processed to TOA reflectance. To cancel production of this band assign value 0.
b7	By default Band7 will be processed to TOA reflectance. To cancel production of this band assign value 0.

Value

Each bands selected will produce corresponding image in *.tif format in the input directory.

Note

1. This function followed by multi.indices is recommended only if user is intended to produce multiple indices like ndvi & gemi other than running seperate function for each product to save processing time and resources.

Other important notes are mentioned in custom.eqn.

References

USGS (2016) Landsat 8 (L8) data users handbook, version 2.

Landsat 7 science data users handbook, NASA. Available at "https://landsat.gsfc.nasa.gov/wp-content/uploads/2016/08/Landsat7_Handbook.pdf".

Examples

library (raster)
library (rgdal)
# Finding the path of the sample satellite image directory.
# User may define paths directly like "/home/ur_folder" or "C:/ur_folder"
path <- system.file ("TM_sample", package = "ASIP")
shapefil <- paste0 (path, "/test.shp")
# Assign 0 values to band names which are not required
dn2toa (path, crop = "f", ext2crop = shapefil, b3=0, b4=0, b5=0, b6 = 0, b7 = 0)

---