pyodim 0.4

An ODIM hdf5 file reader.

PYODIM

A simple ODIM H5 (Opera Data Information Model - Hierarchical Data Format version 5) radar reader in Python. It outputs the radar date in an xarray Dataset. The goal is to be as barebone as possible while providing an xarray, so that it can easily scale up (production) or just a very lean reader for quicklooks into the data.

Example

import pyodim

filename = "/path/to/radar/file.h5"
rset = pyodim.read_odim(filename, lazy_load=True)  # Lazy load does not load the data in memory to save time if you are interested in only a specific sweep
radar = rset[0].compute()  # All sweeps are in a list (elevation ascending), so the 1st item of the list is the bottom sweep.
print(radar)

This code will output the radar data for the first sweep (lowest elevation scan) in the radar file as an xarray Dataset, for example:

<xarray.Dataset>
Dimensions:     (azimuth: 360, range: 1283, elevation: 1, time: 360)
Coordinates:
  * range       (range) float32 125.0 375.0 625.0 ... 3.204e+05 3.206e+05
  * azimuth     (azimuth) float32 0.01111 1.011 2.011 ... 357.0 358.0 359.0
  * elevation   (elevation) float32 0.5
  * time        (time) datetime64[ns] 2024-01-16T02:49:29.337047353 ... 2024-...
Data variables: (12/17)
    DBZH        (azimuth, range) float64 nan nan nan nan nan ... nan nan nan nan
    SNRH        (azimuth, range) float64 nan nan nan nan nan ... nan nan nan nan    
    VRADH       (azimuth, range) float64 nan nan nan nan nan ... nan nan nan nan
    WRADH       (azimuth, range) float64 nan nan nan nan nan ... nan nan nan nan
    KDP         (azimuth, range) float64 nan nan nan nan nan ... nan nan nan nan
    ...          ...
    x           (azimuth, range) float32 0.02424 0.07271 ... -5.595e+03
    y           (azimuth, range) float32 125.0 375.0 ... 3.203e+05 3.206e+05
    z           (azimuth, range) float32 45.09 47.27 ... 2.84e+03 2.842e+03
    longitude   (azimuth, range) float32 144.8 144.8 144.8 ... 144.7 144.7 144.7
    latitude    (azimuth, range) float32 -37.85 -37.85 -37.85 ... -34.97 -34.96
Attributes: (12/15)
    Conventions:  ODIM_H5/V2_4
    latitude:     -37.85200119018555
    longitude:    144.75199890136722
    height:       44.0
    date:         2024-01-16T02:45:21
    object:       PVOL
    ...           ...
    beamwV:       1.0
    wavelength:   10.489999771118164
    NI:           36.5052
    highprf:      696.0
    start_time:   20240116_024928
    end_time:     20240116_024958

PYODIM reads the ODIM radar data and metadata. It also provides some quality of life feature like automatically creating the x, y, z and latitude/longitude coordinates for all radar gates (using the azimuthal equidistant - aeqd - projection). By default it uses dask.delayed to lazily load the data, meaning that it will not actually load all the sweeps in memory, as for many applications we often don't need all the radar sweeps. Instead, by calling the .compute() method like in the example above, PYODIM will only read and load in memory the sweep that you want, saving time. If you want to read all the sweeps at once in a list, then just set lazy_load=False.

Dependencies

Mandatory:

• numpy
• xarray
• pyproj
• dask

And optionally (it will automatically populate the fields metadata using pyart if available):

• Py-ART