Data Model

With the forthcoming standard FM301, which is a subset of CfRadial2.0, as a basis for the xradar data model we can take full advantage of Xarray and the whole software stack.

We facilitate datatree.DataTree to bundle the different sweeps of a radar volume into one structure. These sweep datasets are essentially xarray.Dataset which contain metadata attributes and variables (xarray.DataArray).

DataTree

The DataTree consists of one global root group and several sweep groups. Optionally, groups containing parameter and calibration can be part of the datatree.

Internal representation: datatree.DataTree

Global Scope / Root Group

This group holds data and metadata relevant to the entire volume. These are:

• attributes

• ancillary variables

Internal representation: xarray.Dataset

Sweep Groups

Each of the sweep groups contains data and metadata belonging to a specific sweep. These are:

• dimensions

• coordinates

• ancillary variables

• dataset variables

Internal representation: xarray.Dataset

Dimensions

• time

• range

• frequency

• prt, optional

Coordinates

• time

• range

• frequency

Internal Representation: xarray.DataArray

Ancillary Variables

• sweep_number

• sweep_mode

• follow_mode

• prt_mode

• fixed_angle

• azimuth

• elevation

Internal Representation: xarray.DataArray

Dataset Variables

• DBZH, radar_equivalent_reflectivity_factor_h

• DBZV, radar_equivalent_reflectivity_factor_v

• and many more, see xradar.model.sweep_dataset_vars

Internal Representation: xarray.DataArray