Source code for satpy.readers.eum_base

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (c) 2017-2018 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 <http://www.gnu.org/licenses/>.
"""Utilities for EUMETSAT satellite data."""

from datetime import datetime, timedelta

import numpy as np

# 6 bytes, 8 bytes, 10 bytes
time_cds_short = [('Days', '>u2'), ('Milliseconds', '>u4')]
time_cds = time_cds_short + [('Microseconds', '>u2')]
time_cds_expanded = time_cds + [('Nanoseconds', '>u2')]
issue_revision = [('Issue', np.uint16), ('Revision', np.uint16)]


[docs] def timecds2datetime(tcds): """Convert time_cds-variables to datetime-object. Works both with a dictionary and a numpy record_array. """ days = int(tcds['Days']) milliseconds = int(tcds['Milliseconds']) try: microseconds = int(tcds['Microseconds']) except (KeyError, ValueError): microseconds = 0 try: microseconds += int(tcds['Nanoseconds']) / 1000. except (KeyError, ValueError): pass reference = datetime(1958, 1, 1) delta = timedelta(days=days, milliseconds=milliseconds, microseconds=microseconds) return reference + delta
[docs] def recarray2dict(arr): """Convert numpy record array to a dictionary.""" res = {} tcds_types = [time_cds_short, time_cds, time_cds_expanded] for dtuple in arr.dtype.descr: key = dtuple[0] ntype = dtuple[1] data = arr[key] if ntype in tcds_types: if data.size > 1: res[key] = np.array([timecds2datetime(item) for item in data.ravel()]).reshape(data.shape) else: res[key] = timecds2datetime(data) elif isinstance(ntype, list): res[key] = recarray2dict(data) else: if data.size == 1: data = data[0] if ntype[:2] == '|S': # Python2 and Python3 handle strings differently try: data = data.decode() except ValueError: data = None else: data = data.split(':')[0].strip() res[key] = data else: res[key] = data.squeeze() return res
[docs] def get_service_mode(instrument_name, ssp_lon): """Get information about service mode for a given instrument and subsatellite longitude.""" service_modes = {'seviri': {'0.0': {'service_name': 'fes', 'service_desc': 'Full Earth Scanning service'}, '9.5': {'service_name': 'rss', 'service_desc': 'Rapid Scanning Service'}, '41.5': {'service_name': 'iodc', 'service_desc': 'Indian Ocean Data Coverage service'}, '45.5': {'service_name': 'iodc', 'service_desc': 'Indian Ocean Data Coverage service'} }, 'fci': {'0.0': {'service_name': 'fdss', 'service_desc': 'Full Disk Scanning Service'}, '9.5': {'service_name': 'rss', 'service_desc': 'Rapid Scanning Service'}, }, } unknown_modes = {'service_name': 'unknown', 'service_desc': 'unknown'} return service_modes.get(instrument_name, unknown_modes).get('{:.1f}'.format(ssp_lon), unknown_modes)