#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (c) 2023
#
# This file is part of satpy.
#
# satpy is free software: you can redistribute it and/or modify it under the
# terms of the GNU General Public License as published by the Free Software
# Foundation, either version 3 of the License, or (at your option) any later
# version.
#
# satpy is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with
# satpy. If not, see <http://www.gnu.org/licenses/>.
"""GERB L2 HR HDF5 reader.
A reader for the Top of Atmosphere outgoing fluxes from the Geostationary Earth Radiation
Budget instrument aboard the Meteosat Second Generation satellites.
"""
import datetime as dt
import logging
from satpy.area import get_area_def
from satpy.readers.core.hdf5 import HDF5FileHandler
LOG = logging.getLogger(__name__)
[docs]
def gerb_get_dataset(ds, ds_info):
"""Load a GERB dataset in memory from a HDF5 file or HDF5FileHandler.
The routine takes into account the quantisation factor and fill values.
"""
ds_attrs = ds.attrs
ds_fill = ds_info["fill_value"]
fill_mask = ds != ds_fill
if "Quantisation Factor" in ds_attrs and "Unit" in ds_attrs:
ds = ds*ds_attrs["Quantisation Factor"]
else:
ds = ds*1.
ds = ds.where(fill_mask)
return ds
[docs]
class GERB_HR_FileHandler(HDF5FileHandler):
"""File handler for GERB L2 High Resolution H5 files."""
@property
def end_time(self):
"""Get end time."""
return self.start_time + dt.timedelta(minutes=15)
@property
def start_time(self):
"""Get start time."""
return self.filename_info["sensing_time"]
[docs]
def get_dataset(self, ds_id, ds_info):
"""Read a HDF5 file into an xarray DataArray."""
ds_name = ds_id["name"]
if ds_name not in ["Solar Flux", "Thermal Flux", "Solar Radiance", "Thermal Radiance"]:
raise KeyError(f"{ds_name} is an unknown dataset for this reader.")
ds = gerb_get_dataset(self[f"Radiometry/{ds_name}"], ds_info)
ds.attrs.update({"start_time": self.start_time, "data_time": self.start_time, "end_time": self.end_time})
return ds
[docs]
def get_area_def(self, dsid):
"""Area definition for the GERB product."""
ssp_lon = self.file_content["Geolocation/attr/Nominal Satellite Longitude (degrees)"]
if abs(ssp_lon) < 1e-6:
return get_area_def("msg_seviri_fes_9km")
elif abs(ssp_lon - 9.5) < 1e-6:
return get_area_def("msg_seviri_fes_9km")
elif abs(ssp_lon - 45.5) < 1e-6:
return get_area_def("msg_seviri_iodc_9km")
else:
raise ValueError(f"There is no matching grid for SSP longitude {self.ssp_lon}")