#!/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)