Adding hierarchical radar data

[aladinor]

• updated the docstring for xarray.tutorial.open_dataset
• partially closes #321

[TomNicholas]

Thanks @aladinor !

Can I see what that radar data looks like (i.e. a printed representation of the tree structure) before I merge it?

Also can we rename the file? Currently you would access this like xr.tutorial.open_datatree('radar-dtree'), which says tree twice. I think radar is fine, or even nexrad or similar.

[aladinor]

Hi @TomNicholas

This is the content of the radar file

xarray.DataTree structure

<xarray.DataTree>
Group: /
│   Dimensions:              ()
│   Data variables:
│       volume_number        int64 8B ...
│       platform_type        <U5 20B ...
│       instrument_type      <U5 20B ...
│       time_coverage_start  <U20 80B ...
│       time_coverage_end    <U20 80B ...
│       longitude            float64 8B ...
│       altitude             int64 8B ...
│       latitude             float64 8B ...
│   Attributes:
│       Conventions:      None
│       instrument_name:  KVNX
│       ...
├── Group: /sweep_0
│       Dimensions: (azimuth: 720, range: 1832)
│       Coordinates:
│         * azimuth   (azimuth) float64 ...
│         * range     (range) float32 ...
│         time        (azimuth) datetime64[ns] ...
│         ...
│       Data variables:
│         DBZH, ZDR, PHIDP, RHOHV, ...
├── Group: /sweep_1
│       Dimensions: (azimuth: 720, range: 1192)
│       ...
│       Data variables:
│         DBZH, VRADH, WRADH, ...
├── Group: /sweep_2
│       Dimensions: (azimuth: 720, range: 1832)
│       ...
├── Group: /radar_parameters
│       Dimensions: ()
│       Coordinates: longitude, latitude, altitude
├── Group: /georeferencing_correction
│       Dimensions: ()
│       Coordinates: longitude, latitude, altitude
└── Group: /radar_calibration

and I renamed the file to radar.nc

[keewis]

shall we go ahead and merge this? It would be super helpful to have a native example dataset with multiple data groups somewhere.