Source code for satpy.readers.ghrsst_l2

# -*- coding: utf-8 -*-
# Copyright (c) 2017 - 2022 Satpy developers
# 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 <>.
"""Reader for the GHRSST level-2 formatted data."""

import os
import tarfile
from contextlib import suppress
from datetime import datetime
from functools import cached_property

import xarray as xr

from satpy.readers.file_handlers import BaseFileHandler
from satpy.utils import get_legacy_chunk_size

CHUNK_SIZE = get_legacy_chunk_size()

[docs] class GHRSSTL2FileHandler(BaseFileHandler): """File handler for GHRSST L2 netCDF files.""" def __init__(self, filename, filename_info, filetype_info, engine=None): """Initialize the file handler for GHRSST L2 netCDF data.""" super().__init__(filename, filename_info, filetype_info) self._engine = engine self._tarfile = None self.filename_info['start_time'] = datetime.strptime(, '%Y%m%dT%H%M%SZ') self.filename_info['end_time'] = datetime.strptime(, '%Y%m%dT%H%M%SZ') @cached_property def nc(self): """Get the xarray Dataset for the filename.""" if os.fspath(self.filename).endswith('tar'): file_obj = self._open_tarfile() else: file_obj = self.filename nc = xr.open_dataset(file_obj, decode_cf=True, mask_and_scale=True, engine=self._engine, chunks={'ni': CHUNK_SIZE, 'nj': CHUNK_SIZE}) return nc.rename({'ni': 'x', 'nj': 'y'})
[docs] def _open_tarfile(self): self._tarfile =, mode='r') sst_filename = next((name for name in self._tarfile.getnames() if self._is_sst_file(name))) file_obj = self._tarfile.extractfile(sst_filename) return file_obj
[docs] @staticmethod def _is_sst_file(name): """Check if file in the tar archive is a valid SST file.""" return name.endswith('nc') and 'GHRSST-SSTskin' in name
[docs] def get_dataset(self, key, info): """Get any available dataset.""" stdname = info.get('standard_name') return[stdname].squeeze()
@property def start_time(self): """Get start time.""" return self.filename_info['start_time'] @property def end_time(self): """Get end time.""" return self.filename_info['end_time'] @property def sensor(self): """Get the sensor name.""" return['sensor'].lower() def __del__(self): """Close the tarfile object.""" with suppress(AttributeError): self._tarfile.close()