wradlib.georef.rect.get_radolan_grid

wradlib.georef.rect.get_radolan_grid(nrows=None, ncols=None, trig=False, wgs84=False)

Calculates x/y coordinates of radolan grid of the German Weather Service

Returns the x,y coordinates of the radolan grid positions (lower left corner of every pixel). The radolan grid is a polarstereographic projection, the projection information was taken from RADOLAN-RADVOR-OP Kompositformat_2.2.2 [DWD, 2009]

Coordinates for 900km x 900km grid

Coordinate	lon	lat	x	y
LowerLeft	3.5889E	46.9526N	-523.4622	-4658.645
LowerRight	14.6209E	47.0705N	376.5378	-4658.645
UpperRight	15.7208E	54.7405N	376.5378	-3758.645
UpperLeft	2.0715E	54.5877N	-523.4622	-3758.645

Coordinates for 1100km x 900km grid

Coordinate	lon	lat	x	y
LowerLeft	4.6759E	46.1929N	-443.4622	-4758.645
LowerRight	15.4801E	46.1827N	456.5378	-4758.645
UpperRight	17.1128E	55.5342N	456.5378	-3658.645
UpperLeft	3.0889E	55.5482N	-433.4622	-3658.645

Coordinates for 1500km x 1400km grid

Coordinate	lon	lat	x	y
LowerLeft	2.3419E	43.9336N	-673.4622	-5008.645

Parameters:

• nrows (int) – number of rows (460, 900 by default, 1100, 1500)
• ncols (int) – number of columns (460, 900 by default, 1400)
• trig (boolean) – if True, uses trigonometric formulas for calculation if False, uses osr spatial reference system to transform between projections trig is recommended to be False, however, the two ways of computation are expected to be equivalent.
• wgs84 (boolean) – if True, output coordinates are in wgs84 lonlat format (default: False)

Returns:

radolan_grid (numpy.ndarray) – Array of shape (rows, cols, 2) xy- or lonlat-grid.

Examples

>>> # using osr spatial reference transformation
>>> import wradlib.georef as georef  # noqa
>>> radolan_grid = georef.get_radolan_grid()
>>> print("{0}, ({1:.4f}, {2:.4f})".format(radolan_grid.shape, *radolan_grid[0,0,:]))  # noqa
(900, 900, 2), (-523.4622, -4658.6447)

>>> # using pure trigonometric transformations
>>> import wradlib.georef as georef
>>> radolan_grid = georef.get_radolan_grid(trig=True)
>>> print("{0}, ({1:.4f}, {2:.4f})".format(radolan_grid.shape, *radolan_grid[0,0,:]))  # noqa
(900, 900, 2), (-523.4622, -4658.6447)

>>> # using osr spatial reference transformation
>>> import wradlib.georef as georef
>>> radolan_grid = georef.get_radolan_grid(1500, 1400)
>>> print("{0}, ({1:.4f}, {2:.4f})".format(radolan_grid.shape, *radolan_grid[0,0,:]))  # noqa
(1500, 1400, 2), (-673.4622, -5008.6447)

>>> # using osr spatial reference transformation
>>> import wradlib.georef as georef
>>> radolan_grid = georef.get_radolan_grid(900, 900, wgs84=True)
>>> print("{0}, ({1:.4f}, {2:.4f})".format(radolan_grid.shape, *radolan_grid[0,0,:]))  # noqa
(900, 900, 2), (3.5889, 46.9526)

See Polar Stereographic Projection.

Raises:TypeError, ValueError