Download basemap from Italian National Geoportal

Download the aerial orthophoto of the requested domain from the Italian National Geoportal.

Usage

downloadBasemap(
  file = NULL,
  xSW = NA,
  ySW = NA,
  xExt = NA,
  yExt = NA,
  crs = 32,
  width = 1024,
  height = 1024,
  units = "px",
  res = 72
)

Arguments

file

Path to output file. If file exists, it will be overwritten.

xSW

South West Easting UTM coordinate of the basemap (in metres).

ySW

South West Northing UTM coordinate of the basemap (in metres).

xExt

Easting extension in metres.

yExt

Northing extension in metres.

crs

Coordinate Reference System as UTM zone: either 32 (default) or 33.

width

The basemap width (default = 1024).

height

The basemap height (default = 1024).

units

The unit of measure of width and height. It can be px (pixels, the default), in (inches), cm or mm

res

The resolution in dpi (default = 72).

Value

The output is a tiff encoded with GeoTIFF metadata at the path provided. No value is returned.

Details

The domain is specified by the South-West point coordinates, and its extension in the x and y directions. The Coordinate Reference System (CRS) is in UTM 32 or 33.

Note that, even if the downloading is successful the file might be empty due to some weird behaviour of the remote server from the PCN.

Examples

if (FALSE) { # \dontrun{
# Download a basemap of a domain with SW coordinates (410000, 5000500)
# in the UTM32 CRS and extension 5000m in both directions.

downloadBasemap(
    file = "./basemap.tif",
    xSW = 410000, ySW = 5000500, xExt = 5000, yExt = 5000
)

# Download a basemap of a domain with SW coordinates (410000, 5000500)
# in the UTM32 CRS and extension 5000m in both directions.
# The file has to be 2048 x 2048 pixels.

downloadBasemap(
    file = "./basemap.tif",
    xSW = 410000, ySW = 5000500, xExt = 5000, yExt = 5000,
    width = 2048, height = 2048
)

# Download a basemap of a domain with SW coordinates (410000, 5000500)
# in the UTM32 CRS and extension 5000m in both directions.
# The file has to be 10cm x 10cm with a resolution of 150 dpi.

downloadBasemap(
    file = "./basemap.tif",
    xSW = 410000, ySW = 5000500, xExt = 5000, yExt = 5000,
    width = 10, height = 10, units = "cm", res = 144
)
} # }