R/ucs2latlon.R

In steingod/R-osisaf: Useful functions for handling EUMETSAT Ocean and Sea Ice SAF data

ucs2latlon <- function(northings,eastings) {

    rearth <- 6371.

    deg2rad <- pi/180.

    lattruerad <- 60.*deg2rad
    distpoleq <- rearth*(1.+sin(lattruerad))

    rp <- ((eastings^2)+(northings^2))^0.5

    lat <- 90.-(1./deg2rad)*atan(rp/distpoleq)*2
    lon <- 0+(1./deg2rad)*atan2(eastings,-northings)

    return(data.frame(lat=lat,lon=lon))
}