R/tir.L8DNtoTOARadiance.R

In bwtian/TIR: Thermal Infrared Remote Sensing

#' creates a raster with the TOA radiance
#'
#' @description Creates a raster with the TOA radiance
#'
#' @param landsat8 list returned by rLandsat8::ReadLandsat8
#' @param band Landsat 11 bandname (one of "aerosol", "blue", "green", "red", "nir", "swir1", "swir2", "panchromatic", "cirrus", "tirs1", "tirs2"
#' @return TOA Radiance raster
#' @examples \dontrun{
#' ls8 <- ReadLandsat8("LC81880342014174LGN00")
#' r <- ToTOARadiance(ls8, "red")
#' }
#' @note code form rLandsat8
#' @export
#' @import raster

 ToTOARadiance <- function(landsat8, band) {

   bandnames <-c("aerosol", "blue", "green", "red",
   "nir", "swir1", "swir2",
   "panchromatic",
   "cirrus",
   "tirs1", "tirs2")

   allowedbands <- bandnames

   if (!band %in% allowedbands)
   {
        stop(paste(band, "band not allowed"))
   }

   idx <- seq_along(bandnames)[sapply(bandnames, function(x) band %in% x)]

   ml <- as.numeric(landsat8$metadata[[paste0("radiance_mult_band_",idx)]])
   al <- as.numeric(landsat8$metadata[[paste0("radiance_add_band_",idx)]])

   TOArad <- landsat8$band[[band]] * ml + al

   return(TOArad)

 }

 ## Add new
 l8.DNtoTOARadiance <- function(idenfier){
bandnames <-c("aerosol", "blue", "green", "red",
   "nir", "swir1", "swir2",
   "panchromatic",
   "cirrus",
   "tirs1", "tirs2")

   sapply(bandnames, function(i){ToTOARadiance(idenfier, i)})
 }