wradlib.io.radolan.read_radolan_composite(f, missing=-9999, loaddata=True)

Read quantitative radar composite format of the German Weather Service

The quantitative composite format of the DWD (German Weather Service) was established in the course of the RADOLAN project and includes several file types, e.g. RX, RO, RK, RZ, RP, RT, RC, RI, RG, PC, PG and many, many more. (see format description on the RADOLAN project homepage [DWD2009]). At the moment, the national RADOLAN composite is a 900 x 900 grid with 1 km resolution and in polar-stereographic projection. There are other grid resolutions for different composites (eg. PC, PG)


This function already evaluates and applies the so-called PR factor which is specified in the header section of the RADOLAN files. The raw values in an RY file are in the unit 0.01 mm/5min, while read_radolan_composite returns values in mm/5min (i. e. factor 100 higher). The factor is also returned as part of attrs dictionary under keyword “precision”.


Using loaddata=’xarray’ the data is wrapped in an xarray Dataset. x,y, dimension as well as x,y and time coordinates (polar stereographic projection) are supplied.

  • f (string or file handle) – path to the composite file or file handle
  • missing (int) – value assigned to no-data cells
  • loaddata (bool | str) – True | False | ‘xarray’, If False function returns (None, attrs) If ‘xarray’ returns (xarray Dataset, attrs)

output (tuple) –

tuple of two items (data, attrs):
  • data : numpy.array of shape (number of rows, number of columns) | xarray.Dataset
  • attrs : dictionary of metadata information from the file header


See RADOLAN binary data format.