#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright (c) 2019 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/>.
"""Geostationary project utility module tests package."""
import unittest
import numpy as np
from satpy.readers._geos_area import (
get_area_definition,
get_area_extent,
get_geos_area_naming,
get_resolution_and_unit_strings,
get_xy_from_linecol,
sampling_to_lfac_cfac,
)
[docs]class TestGEOSProjectionUtil(unittest.TestCase):
"""Tests for the area utilities."""
[docs] def make_pdict_ext(self, typ, scan):
"""Create a dictionary and extents to use in testing."""
if typ == 1: # Fulldisk
pdict = {'a': 6378169.00,
'b': 6356583.80,
'h': 35785831.00,
'ssp_lon': 0.0,
'nlines': 3712,
'ncols': 3712,
'a_name': 'geostest',
'a_desc': 'test area',
'p_id': 'test_area',
'cfac': -13642337,
'lfac': -13642337,
'coff': 1856}
if scan == 'N2S':
pdict['scandir'] = 'N2S'
pdict['loff'] = 1856
extent = (5567248.28340708,
5567248.28340708,
-5570248.686685662,
-5570248.686685662)
if scan == 'S2N':
pdict['scandir'] = 'S2N'
pdict['loff'] = -1856
extent = (5567248.28340708,
5570248.686685662,
-5570248.686685662,
-5567248.28340708)
if typ == 2: # One sector
pdict = {'a': 6378169.00,
'b': 6356583.80,
'h': 35785831.00,
'ssp_lon': 0.0,
'nlines': 464,
'ncols': 3712,
'a_name': 'geostest',
'a_desc': 'test area',
'p_id': 'test_area',
'cfac': -13642337,
'lfac': -13642337,
'coff': 1856}
if scan == 'N2S':
pdict['scandir'] = 'N2S'
pdict['loff'] = 464
extent = (5567248.28340708,
1390686.9196223018,
-5570248.686685662,
-1500.2016392905093)
if scan == 'S2N':
pdict['scandir'] = 'S2N'
pdict['loff'] = 464
extent = (5567248.28340708,
-1390686.9196223018,
-5570248.686685662,
-2782874.0408838945)
return pdict, extent
[docs] def test_geos_area(self):
"""Test area extent calculation with N->S scan then S->N scan."""
# North -> South full disk
pdict, extent = self.make_pdict_ext(1, 'N2S')
aex = get_area_extent(pdict)
np.testing.assert_allclose(aex, extent)
# South -> North full disk
pdict, extent = self.make_pdict_ext(1, 'S2N')
aex = get_area_extent(pdict)
np.testing.assert_allclose(aex, extent)
# North -> South one sector
pdict, extent = self.make_pdict_ext(2, 'N2S')
aex = get_area_extent(pdict)
np.testing.assert_allclose(aex, extent)
# South -> North one sector
pdict, extent = self.make_pdict_ext(2, 'S2N')
aex = get_area_extent(pdict)
np.testing.assert_allclose(aex, extent)
[docs] def test_get_xy_from_linecol(self):
"""Test the scan angle calculation."""
pdict, extent = self.make_pdict_ext(1, 'S2N')
good_xy = [0.2690166648133674, -10.837528496767087]
factors = (pdict['lfac'], pdict['cfac'])
offsets = (pdict['loff'], pdict['coff'])
x, y = get_xy_from_linecol(400, 1800, offsets, factors)
np.testing.assert_approx_equal(x, good_xy[0])
np.testing.assert_approx_equal(y, good_xy[1])
pdict, extent = self.make_pdict_ext(2, 'N2S')
good_xy = [0.2690166648133674, 0.30744761692956274]
factors = (pdict['lfac'], pdict['cfac'])
offsets = (pdict['loff'], pdict['coff'])
x, y = get_xy_from_linecol(400, 1800, offsets, factors)
np.testing.assert_approx_equal(x, good_xy[0])
np.testing.assert_approx_equal(y, good_xy[1])
[docs] def test_get_area_definition(self):
"""Test the retrieval of the area definition."""
from pyresample.utils import proj4_radius_parameters
pdict, extent = self.make_pdict_ext(1, 'N2S')
good_res = (-3000.4032785810186, -3000.4032785810186)
a_def = get_area_definition(pdict, extent)
self.assertEqual(a_def.area_id, pdict['a_name'])
self.assertEqual(a_def.resolution, good_res)
self.assertEqual(a_def.proj_dict['proj'], 'geos')
self.assertEqual(a_def.proj_dict['units'], 'm')
a, b = proj4_radius_parameters(a_def.proj_dict)
self.assertEqual(a, 6378169)
self.assertEqual(b, 6356583.8)
self.assertEqual(a_def.proj_dict['h'], 35785831)
[docs] def test_sampling_to_lfac_cfac(self):
"""Test conversion from angular sampling to line/column offset."""
lfac = 13642337 # SEVIRI LFAC
sampling = np.deg2rad(2 ** 16 / lfac)
np.testing.assert_allclose(sampling_to_lfac_cfac(sampling), lfac)
[docs] def test_get_geos_area_naming(self):
"""Test the geos area naming function."""
input_dict = {'platform_name': 'testplatform',
'instrument_name': 'testinstrument',
'resolution': 1000,
'service_name': 'testservicename',
'service_desc': 'testdesc'}
output_dict = get_geos_area_naming(input_dict)
self.assertEqual(output_dict['area_id'], 'testplatform_testinstrument_testservicename_1km')
self.assertEqual(output_dict['description'], 'TESTPLATFORM TESTINSTRUMENT testdesc area definition'
' with 1 km resolution')
[docs] def test_get_resolution_and_unit_strings_in_km(self):
"""Test the resolution and unit strings function for a km resolution."""
out = get_resolution_and_unit_strings(1000)
self.assertEqual(out['value'], '1')
self.assertEqual(out['unit'], 'km')
[docs] def test_get_resolution_and_unit_strings_in_m(self):
"""Test the resolution and unit strings function for a m resolution."""
out = get_resolution_and_unit_strings(500)
self.assertEqual(out['value'], '500')
self.assertEqual(out['unit'], 'm')