R/TOA_h.r

In carlosfperuchena/satellite2ground: Local adaptation of modeled solar irradiance series with coincident ground measurements

#'  Calculation of the Top of Atmosphere (TOA) solar irradiance on a horizontal plane
#'
#' @param latitude Elevation angle (radians) (for the sun or for satellite)
#' @param Time_Stamp Time: UTC time stamp, in format "YYYY-MM-DD hh:mm:ss"
#' @param Sun_elev Sun elevation angle (degrees) above horizon
#'
#' @return TOA_h Solar irradiance on a horizontal plane
#'
#' @export

TOA_h <- function(latitude,Sun_elev,Time_Stamp){

  solDs<-fSolD(latitude,Time_Stamp)
  yyyy_mm_dd_df=data.frame(yyyy_mm_dd=year(Time_Stamp)*1000 + doy(Time_Stamp))
  yyyy_mm_dd_unico=unique(yyyy_mm_dd_df$yyyy_mm_dd)
  Eo=as.numeric(solDs[,2])
  TOA = Eo*1367
  df_Eo=data.frame(Eo=Eo, yyyy_mm_dd=yyyy_mm_dd_unico, TOA = TOA)
  df_todo_Eo=merge(df_Eo,yyyy_mm_dd_df, by="yyyy_mm_dd",all=TRUE )
  TOA_h = df_todo_Eo$TOA*sin(Sun_elev*pi/180)

return(TOA_h)
}