Empedrado <- readOGR("Empedrado.shp") 		# loads the shapefile

# change the coordinate system to match the same from the images #
Empedrado <- spTransform(Empedrado, CRS("+proj=utm +zone=18 +datum=WGS84 +units=m +no_defs +ellps=WGS84 +towgs84=0,0,0"))