Source code for pyart.aux_io.odim_h5

Routines for reading ODIM_H5 files.


import datetime

import numpy as np

    import h5py

    _H5PY_AVAILABLE = True
except ImportError:
    _H5PY_AVAILABLE = False

from ..config import FileMetadata, get_fillvalue
from ..core.radar import Radar
from ..exceptions import MissingOptionalDependency
from import _test_arguments, make_time_unit_str

    "TH": "total_power_horizontal",  # uncorrected reflectivity, horizontal
    "TV": "total_power_vertical",  # uncorrected reflectivity, vertical
    "DBZH": "reflectivity_horizontal",  # corrected reflectivity, horizontal
    "DBZV": "reflectivity_vertical",  # corrected reflectivity, vertical
    "ZDR": "differential_reflectivity",  # differential reflectivity
    "RHOHV": "cross_correlation_ratio",
    "LDR": "linear_polarization_ratio",
    "PHIDP": "differential_phase",
    "KDP": "specific_differential_phase",
    "SQI": "normalized_coherent_power",
    "SNR": "signal_to_noise_ratio",
    "VRAD": "velocity",  # radial velocity, marked for deprecation in ODIM HDF5 2.2
    "VRADH": "velocity_horizontal",  # radial velocity, horizontal polarisation
    "VRADV": "velocity_vertical",  # radial velocity, vertical polarisation
    "WRAD": "spectrum_width",
    "QIND": "quality_index",

[docs]def read_odim_h5( filename, field_names=None, additional_metadata=None, file_field_names=False, exclude_fields=None, include_fields=None, include_datasets=None, exclude_datasets=None, **kwargs ): """ Read a ODIM_H5 file. Parameters ---------- filename : str Name of the ODIM_H5 file to read. field_names : dict, optional Dictionary mapping ODIM_H5 field names to radar field names. If a data type found in the file does not appear in this dictionary or has a value of None it will not be placed in the radar.fields dictionary. A value of None, the default, will use the mapping defined in the Py-ART configuration file. additional_metadata : dict of dicts, optional Dictionary of dictionaries to retrieve metadata from during this read. This metadata is not used during any successive file reads unless explicitly included. A value of None, the default, will not introduct any addition metadata and the file specific or default metadata as specified by the Py-ART configuration file will be used. file_field_names : bool, optional True to use the MDV data type names for the field names. If this case the field_names parameter is ignored. The field dictionary will likely only have a 'data' key, unless the fields are defined in `additional_metadata`. exclude_fields : list or None, optional List of fields to exclude from the radar object. This is applied after the `file_field_names` and `field_names` parameters. Set to None to include all fields specified by include_fields. include_fields : list or None, optional List of fields to include from the radar object. This is applied after the `file_field_names` and `field_names` parameters. Set to None to include all fields not specified by exclude_fields. include_datasets : list or None, optional List of datasets to include from the HDF5 file, given as ["dataset1", "dataset2", ...]. Set to None to include all datasets not specified by exclude_datasets. exclude_datasets : list or None, optional List of datasets to exclude from the HDF5 file, given as ["dataset1", "dataset2", ...]. Set to None to include all datasets specified by include_datasets. Returns ------- radar : Radar Radar object containing data from ODIM_H5 file. """ # TODO before moving to # * unit test # * add default field mapping, etc to default config # * auto-detect file type with function # * instrument parameters # * add additional checks for HOW attributes # * support for other objects (SCAN, XSEC) # check that h5py is available if not _H5PY_AVAILABLE: raise MissingOptionalDependency( "h5py is required to use read_odim_h5 but is not installed" ) # test for non empty kwargs _test_arguments(kwargs) # create metadata retrieval object if field_names is None: field_names = ODIM_H5_FIELD_NAMES filemetadata = FileMetadata( "odim_h5", field_names, additional_metadata, file_field_names, exclude_fields, include_fields, ) # open the file with h5py.File(filename, "r") as hfile: odim_object = _to_str(hfile["what"].attrs["object"]) if odim_object not in ["PVOL", "SCAN", "ELEV", "AZIM"]: raise NotImplementedError("object: %s not implemented." % (odim_object)) # determine the number of sweeps by the number of groups which # begin with dataset if include_datasets is not None: datasets = [ k for k in hfile if k.startswith("dataset") and k in include_datasets ] elif exclude_datasets is not None: datasets = [ k for k in hfile if k.startswith("dataset") and k not in exclude_datasets ] else: datasets = [k for k in hfile if k.startswith("dataset")] datasets.sort(key=lambda x: int(x[7:])) nsweeps = len(datasets) # latitude, longitude and altitude latitude = filemetadata("latitude") longitude = filemetadata("longitude") altitude = filemetadata("altitude") h_where = hfile["where"].attrs latitude["data"] = np.array([h_where["lat"]], dtype="float64") longitude["data"] = np.array([h_where["lon"]], dtype="float64") altitude["data"] = np.array([h_where["height"]], dtype="float64") # metadata metadata = filemetadata("metadata") metadata["source"] = _to_str(hfile["what"].attrs["source"]) metadata["original_container"] = "odim_h5" metadata["odim_conventions"] = _to_str(hfile.attrs["Conventions"]) h_what = hfile["what"].attrs metadata["version"] = _to_str(h_what["version"]) metadata["source"] = _to_str(h_what["source"]) try: ds1_how = hfile[datasets[0]]["how"].attrs except KeyError: # if no how group exists mock it with an empty dictionary ds1_how = {} if "system" in ds1_how: metadata["system"] = ds1_how["system"] if "software" in ds1_how: metadata["software"] = ds1_how["software"] if "sw_version" in ds1_how: metadata["sw_version"] = ds1_how["sw_version"] # sweep_start_ray_index, sweep_end_ray_index sweep_start_ray_index = filemetadata("sweep_start_ray_index") sweep_end_ray_index = filemetadata("sweep_end_ray_index") if odim_object in ["AZIM", "SCAN", "PVOL"]: rays_per_sweep = [int(hfile[d]["where"].attrs["nrays"]) for d in datasets] elif odim_object == "ELEV": rays_per_sweep = [ int(hfile[d]["where"].attrs["angles"].size) for d in datasets ] total_rays = sum(rays_per_sweep) ssri = np.cumsum(np.append([0], rays_per_sweep[:-1])).astype("int32") seri = np.cumsum(rays_per_sweep).astype("int32") - 1 sweep_start_ray_index["data"] = ssri sweep_end_ray_index["data"] = seri # sweep_number sweep_number = filemetadata("sweep_number") sweep_number["data"] = np.arange(nsweeps, dtype="int32") # sweep_mode sweep_mode = filemetadata("sweep_mode") sweep_mode["data"] = np.array(nsweeps * ["azimuth_surveillance"]) # scan_type if odim_object == "ELEV": scan_type = "rhi" else: scan_type = "ppi" # fixed_angle fixed_angle = filemetadata("fixed_angle") if odim_object == "ELEV": sweep_el = [hfile[d]["where"].attrs["az_angle"] for d in datasets] else: sweep_el = [hfile[d]["where"].attrs["elangle"] for d in datasets] fixed_angle["data"] = np.array(sweep_el, dtype="float32") # elevation elevation = filemetadata("elevation") if "elangles" in ds1_how: edata = np.empty(total_rays, dtype="float32") for d, start, stop in zip(datasets, ssri, seri): edata[start : stop + 1] = hfile[d]["how"].attrs["elangles"][:] elevation["data"] = edata elif odim_object == "ELEV": edata = np.empty(total_rays, dtype="float32") for d, start, stop in zip(datasets, ssri, seri): edata[start : stop + 1] = hfile[d]["where"].attrs["angles"][:] elevation["data"] = edata else: elevation["data"] = np.repeat(sweep_el, rays_per_sweep) # range _range = filemetadata("range") if "rstart" in hfile["dataset1/where"].attrs: # derive range from rstart and rscale attributes if available # check that the gate spacing is constant between sweeps rstart = [hfile[d]["where"].attrs["rstart"] for d in datasets] if any(rstart != rstart[0]): raise ValueError("range start changes between sweeps") rscale = [hfile[d]["where"].attrs["rscale"] for d in datasets] if any(rscale != rscale[0]): raise ValueError("range scale changes between sweeps") all_sweeps_nbins = [hfile[d]["where"].attrs["nbins"] for d in datasets] # check for max range off all sweeps max_nbins = max(all_sweeps_nbins) if isinstance(max_nbins, np.ndarray): max_nbins = max_nbins[0] else: max_nbins = max(all_sweeps_nbins) rscenter = 1e3 * rstart[0] + rscale[0] / 2 _range["data"] = np.arange( rscenter, rscenter + max_nbins * rscale[0], rscale[0], dtype="float32" ) _range["meters_to_center_of_first_gate"] = rstart[0] * 1000.0 _range["meters_between_gates"] = float(rscale[0]) else: # if not defined use range attribute which defines the maximum range # in km. There is no information on the starting location of the # range bins so we assume this to be 0. # This most often occurs in RHI files, which technically do not meet # the ODIM 2.2 specs. Section 7.4 requires that these files include # the where/rstart, where/rscale and where/nbins attributes. max_range = [hfile[d]["where"].attrs["range"] for d in datasets] if any(max_range != max_range[0]): raise ValueError("maximum range changes between sweeps") # nbins is required nbins = hfile["dataset1/data1/data"].shape[1] _range["data"] = np.linspace(0, max_range[0] * 1000.0, nbins).astype( "float32" ) _range["meters_to_center_of_first_gate"] = 0 _range["meters_between_gates"] = max_range[0] * 1000.0 / nbins # azimuth azimuth = filemetadata("azimuth") az_data = np.ones((total_rays,), dtype="float32") for dset, start, stop in zip(datasets, ssri, seri): if odim_object == "ELEV": # all azimuth angles are the sweep azimuth angle sweep_az = hfile[dset]["where"].attrs["az_angle"] elif odim_object == "AZIM": # Sector azimuths are specified in the startaz and stopaz # attribute of dataset/where. # Assume that the azimuth angles do not pass through 0/360 deg. startaz = hfile[dset]["where"].attrs["startaz"] stopaz = hfile[dset]["where"].attrs["stopaz"] nrays = stop - start + 1 sweep_az = np.linspace(startaz, stopaz, nrays, endpoint=True) elif ("startazA" in ds1_how) and ("stopazA" in ds1_how): # average between start and stop azimuth angles startaz = hfile[dset]["how"].attrs["startazA"] stopaz = hfile[dset]["how"].attrs["stopazA"] sweep_az = np.angle( ( np.exp(1.0j * np.deg2rad(startaz)) + np.exp(1.0j * np.deg2rad(stopaz)) ) / 2.0, deg=True, ) else: # according to section 5.1 the first ray points to the # northernmost direction and proceeds clockwise for a complete # 360 rotation. try: astart = hfile[dset]["how"].attrs["astart"] except KeyError: astart = 0.0 nrays = hfile[dset]["where"].attrs["nrays"] da = 360.0 / nrays sweep_az = np.arange(astart + da / 2.0, 360.0, da, dtype="float32") az_data[start : stop + 1] = sweep_az azimuth["data"] = az_data # time _time = filemetadata("time") if ("startazT" in ds1_how) and ("stopazT" in ds1_how): # average between startazT and stopazT t_data = np.empty((total_rays,), dtype="float64") for dset, start, stop in zip(datasets, ssri, seri): t_start = hfile[dset]["how"].attrs["startazT"] t_stop = hfile[dset]["how"].attrs["stopazT"] t_data[start : stop + 1] = (t_start + t_stop) / 2 start_epoch = t_data.min() start_time = datetime.datetime.utcfromtimestamp(start_epoch) _time["units"] = make_time_unit_str(start_time) _time["data"] = t_data - start_epoch else: t_data = np.empty((total_rays,), dtype="int32") # interpolate between each sweep starting and ending time for dset, start, stop in zip(datasets, ssri, seri): dset_what = hfile[dset]["what"].attrs start_str = _to_str(dset_what["startdate"] + dset_what["starttime"]) end_str = _to_str(dset_what["enddate"] + dset_what["endtime"]) start_dt = datetime.datetime.strptime(start_str, "%Y%m%d%H%M%S") end_dt = datetime.datetime.strptime(end_str, "%Y%m%d%H%M%S") time_delta = end_dt - start_dt delta_seconds = time_delta.seconds + time_delta.days * 3600 * 24 rays = stop - start + 1 sweep_start_epoch = ( start_dt - datetime.datetime(1970, 1, 1) ).total_seconds() t_data[start : stop + 1] = sweep_start_epoch + np.linspace( 0, delta_seconds, rays ) start_epoch = t_data.min() start_time = datetime.datetime.utcfromtimestamp(start_epoch) _time["units"] = make_time_unit_str(start_time) _time["data"] = (t_data - start_epoch).astype("float32") # fields fields = {} h_field_keys = [k for k in hfile["dataset1"] if k.startswith("data")] odim_fields = [ hfile["dataset1"][d]["what"].attrs["quantity"] for d in h_field_keys ] for odim_field, h_field_key in zip(odim_fields, h_field_keys): field_name = filemetadata.get_field_name(_to_str(odim_field)) if field_name is None: continue fdata =, max_nbins), dtype="float32") start = 0 # loop on the sweeps, copy data into correct location in data array for dset, rays_in_sweep in zip(datasets, rays_per_sweep): try: sweep_data = _get_odim_h5_sweep_data(hfile[dset][h_field_key]) except KeyError: sweep_data = np.zeros((rays_in_sweep, max_nbins)) + np.NaN sweep_nbins = sweep_data.shape[1] fdata[start : start + rays_in_sweep, :sweep_nbins] = sweep_data[:] # set data to NaN if its beyond the range of this sweep fdata[start : start + rays_in_sweep, sweep_nbins:max_nbins] = np.nan start += rays_in_sweep # create field dictionary field_dic = filemetadata(field_name) field_dic["data"] = fdata field_dic["_FillValue"] = get_fillvalue() fields[field_name] = field_dic # instrument_parameters instrument_parameters = None return Radar( _time, _range, fields, metadata, scan_type, latitude, longitude, altitude, sweep_number, sweep_mode, fixed_angle, sweep_start_ray_index, sweep_end_ray_index, azimuth, elevation, instrument_parameters=instrument_parameters, )
def _to_str(text): """Convert bytes to str if necessary.""" if hasattr(text, "decode"): return text.decode("utf-8") else: return text def _get_odim_h5_sweep_data(group): """Get ODIM_H5 sweet data from an HDF5 group.""" # mask raw data what = group["what"] raw_data = group["data"][:] if "nodata" in what.attrs: nodata = what.attrs.get("nodata") data =, nodata) else: data = if "undetect" in what.attrs: undetect = what.attrs.get("undetect") data[data == undetect] = offset = 0.0 gain = 1.0 if "offset" in what.attrs: offset = what.attrs.get("offset") if "gain" in what.attrs: gain = what.attrs.get("gain") return data * gain + offset