xarray RADOLAN backend#
In this example, we read RADOLAN data files using the xarray radolan backend.
import glob
import os
import wradlib as wrl
import wradlib_data
import warnings
from IPython.display import display
import matplotlib.pyplot as plt
import numpy as np
import xarray as xr
warnings.filterwarnings("ignore")
Load RADOLAN Data#
fpath = "radolan/misc/raa01-rw_10000-1408030950-dwd---bin.gz"
f = wradlib_data.DATASETS.fetch(fpath)
comp = wrl.io.open_radolan_dataset(f)
Downloading file 'radolan/misc/raa01-rw_10000-1408030950-dwd---bin.gz' from 'https://github.com/wradlib/wradlib-data/raw/main/data/radolan/misc/raa01-rw_10000-1408030950-dwd---bin.gz' to '/home/docs/.cache/wradlib-data'.
Inspect Data#
display(comp)
<xarray.Dataset> Size: 3MB
Dimensions: (y: 900, x: 900, time: 1)
Coordinates:
* y (y) float64 7kB -4.658e+06 -4.657e+06 ... -3.76e+06 -3.759e+06
* x (x) float64 7kB -5.23e+05 -5.22e+05 -5.21e+05 ... 3.75e+05 3.76e+05
* time (time) datetime64[ns] 8B 2014-08-03T09:50:00
Data variables:
RW (y, x) float32 3MB ...
crs int64 8B ...
Attributes:
radarid: 10000
formatversion: 3
radolanversion: 2.13.1
radarlocations: ['boo', 'ros', 'emd', 'hnr', 'pro', 'ess', 'asd', 'neu',...Inspect RADOLAN moments#
The DataArrays can be accessed by key or by attribute. Each DataArray has dimensions and coordinates of its parent dataset.
display(comp.RW)
<xarray.DataArray 'RW' (y: 900, x: 900)> Size: 3MB
[810000 values with dtype=float32]
Coordinates:
* y (y) float64 7kB -4.658e+06 -4.657e+06 ... -3.76e+06 -3.759e+06
* x (x) float64 7kB -5.23e+05 -5.22e+05 -5.21e+05 ... 3.75e+05 3.76e+05
Attributes:
valid_min: 0
valid_max: 4095
standard_name: rainfall_rate
long_name: RW
unit: mm h-1
grid_mapping: crsCreate simple plot#
Using xarray features a simple plot can be created like this.
comp.RW.plot(x="x", y="y", add_labels=False)
<matplotlib.collections.QuadMesh at 0x7ee6c79d9a90>
fig = plt.figure(figsize=(10, 10))
ax = fig.add_subplot(111)
comp.RW.plot(x="x", y="y", ax=ax)
<matplotlib.collections.QuadMesh at 0x7ee6c76a3750>
Mask some values#
ds = comp["RW"].where(comp["RW"] >= 1)
ds.plot()
<matplotlib.collections.QuadMesh at 0x7ee6c75b4910>
Use xr.open_dataset#
comp2 = xr.open_dataset(f, engine="radolan")
display(comp2)
<xarray.Dataset> Size: 3MB
Dimensions: (y: 900, x: 900, time: 1)
Coordinates:
* y (y) float64 7kB -4.658e+06 -4.657e+06 ... -3.76e+06 -3.759e+06
* x (x) float64 7kB -5.23e+05 -5.22e+05 -5.21e+05 ... 3.75e+05 3.76e+05
* time (time) datetime64[ns] 8B 2014-08-03T09:50:00
Data variables:
RW (y, x) float32 3MB ...
crs int64 8B ...
Attributes:
radarid: 10000
formatversion: 3
radolanversion: 2.13.1
radarlocations: ['boo', 'ros', 'emd', 'hnr', 'pro', 'ess', 'asd', 'neu',...Use xr.open_mfdataset to retrieve timeseries#
flist = [
"radolan/misc/raa01-sf_10000-1305270050-dwd---bin.gz",
"radolan/misc/raa01-sf_10000-1305280050-dwd---bin.gz",
]
flist = [wradlib_data.DATASETS.fetch(f) for f in flist]
Downloading file 'radolan/misc/raa01-sf_10000-1305270050-dwd---bin.gz' from 'https://github.com/wradlib/wradlib-data/raw/main/data/radolan/misc/raa01-sf_10000-1305270050-dwd---bin.gz' to '/home/docs/.cache/wradlib-data'.
Downloading file 'radolan/misc/raa01-sf_10000-1305280050-dwd---bin.gz' from 'https://github.com/wradlib/wradlib-data/raw/main/data/radolan/misc/raa01-sf_10000-1305280050-dwd---bin.gz' to '/home/docs/.cache/wradlib-data'.
comp3 = xr.open_mfdataset(flist, engine="radolan")
display(comp3)
<xarray.Dataset> Size: 6MB
Dimensions: (time: 2, y: 900, x: 900)
Coordinates:
* time (time) datetime64[ns] 16B 2013-05-27T00:50:00 2013-05-28T00:50:00
* y (y) float64 7kB -4.658e+06 -4.657e+06 ... -3.76e+06 -3.759e+06
* x (x) float64 7kB -5.23e+05 -5.22e+05 -5.21e+05 ... 3.75e+05 3.76e+05
Data variables:
SF (time, y, x) float32 6MB dask.array<chunksize=(1, 900, 900), meta=np.ndarray>
crs (time) int64 16B 0 0
Attributes:
radarid: 10000
formatversion: 3
radolanversion: 2.12.0
radarlocations: ['ham', 'ros', 'emd', 'han', 'bln', 'ess', 'fld', 'drs',...
radardays: ['bln 24', 'drs 24', 'eis 24', 'emd 24', 'ess 24', 'fld ...