def test_calibration_is_smooth(self):
"""Test that calibration is smooth in time."""
coefs1 = calib.get_calibration(platform='MSG3',
time=dt.datetime(2018, 1, 18, 23, 59))
coefs2 = calib.get_calibration(platform='MSG3',
time=dt.datetime(2018, 1, 19))
self._assert_coefs_close(coefs1, coefs2, atol=1e-4)
def test_clip_at_time_coverage_bounds(self, coverage_boundary,
outside_coverage):
"""Test clipping beyond time coverage of the calibration dataset."""
coefs1 = calib.get_calibration(platform='MSG1', time=coverage_boundary)
coefs2 = calib.get_calibration(platform='MSG1',
time=outside_coverage,
clip=True)
self._assert_coefs_close(coefs1, coefs2)
def load_and_calibrate(filenames, apply_sun_earth_distance_correction, rotate,
clip_calib):
"""Load and calibrate data.
Uses inter-calibration coefficients from Meirink et al.
Args:
filenames: List of data files
apply_sun_earth_distance_correction: If True, apply sun-earth-distance-
correction to visible channels.
rotate: Rotate image so that pixel (0, 0) is N-W.
clip_calib: If True, do not extrapolate calibration coefficients beyond
the time coverage of the calibration dataset. Instead, clip at the
boundaries.
Returns:
Satpy scene holding calibrated channels
"""
# Parse filenames
parser = SEVIRIFilenameParser()
file_format, info = parser.parse(os.path.basename(filenames[0]))
calib_coefs = get_calibration(platform=info['platform_shortname'],
time=info['start_time'],
clip=clip_calib)
scn_ = _create_scene(file_format, filenames, calib_coefs)
_check_is_seviri_data(scn_)
_load_bands(scn_, rotate)
_update_scene_attrs(scn_, {'image_rotated': rotate})
if not apply_sun_earth_distance_correction:
remove_sun_earth_distance_correction(scn_)
return scn_
def test_get_calibration_can_handle_both_date_and_time(self, time):
"""Test MODIS-intercalibrated gain and offset for specific date."""
coefs = calib.get_calibration(platform='MSG3', time=time)
REF = {
'VIS006': {
'gain': 0.023689275200000002,
'offset': -1.2081530352
},
'VIS008': {
'gain': 0.029757990399999996,
'offset': -1.5176575103999999
},
'IR_016': {
'gain': 0.0228774688,
'offset': -1.1667509087999999
}
}
self._assert_coefs_close(coefs, REF)
def test_fails_with_invalid_time(self):
"""Test that calibration fails with timestamps < reference time."""
with pytest.raises(ValueError):
calib.get_calibration(platform='MSG1',
time=dt.datetime(1999, 1, 1))
def test_get_calibration(self, platform, timestamp, expected):
"""Test MODIS-intercalibrated gain and offset for specific time."""
coefs = calib.get_calibration(platform=platform, time=timestamp)
self._assert_coefs_close(coefs, expected)