Changed azimuth angle range to ]-180, 180]

pygac/gac_reader.py

@@ -472,6 +472,12 @@ def get_angles(self):
         sun_azi = np.rad2deg(sun_azi)
         rel_azi = get_absolute_azimuth_angle_diff(sun_azi, sat_azi)
 
+        # Scale angles to ]-180, 180].
+        sun_azi = sun_azi % 360.0
+        sat_azi = sat_azi % 360.0
+        sun_azi[sun_azi > 180] = sun_azi[sun_azi > 180] - 360
+        sat_azi[sat_azi > 180] = sat_azi[sat_azi > 180] - 360
+
         # Mask corrupt scanlines
         for arr in (sat_azi, sat_zenith, sun_azi, sun_zenith, rel_azi):
             arr[self.mask] = np.nan

pygac/tests/test_reader.py

@@ -192,9 +192,50 @@ def test_get_tle_lines(self, read_tle_file, *mocks):
                 self.assertEqual(tle1, tle_data[tle_idx])
                 self.assertEqual(tle2, tle_data[tle_idx + 1])
 
+    @mock.patch('pygac.gac_reader.GACReader._get_corrupt_mask')
+    def test_get_angles(self, get_corrupt_mask):
+        """Test get_angles function of the reader."""
+        # Line: 1, 649, 6198 and 12658 from Tiros-N file (1980-01-03 11:47)
+        lon_i = np.array(
+            [69.41555, 152.10587, 164.3131, 67.23855])[:, np.newaxis]
+        lat_i = np.array(
+            [71.6283, 85.24265, -62.076958, 82.72296])[:, np.newaxis]
+        get_corrupt_mask.return_value = np.isnan(lon_i)
+        self.reader.lons = lon_i
+        self.reader.lats = lat_i
+        self.reader.tle_lines = [
+            '1 11060U 78096A   80003.54792075  .00000937  00000-0  52481-3 0  2588\r\n',
+            '2 11060  98.9783 332.1605 0012789  88.8047 271.4583 14.11682873 63073\r\n']
+        self.reader.utcs = np.array(
+            [315748035469, 315748359969,
+             315751135469, 315754371969]).astype('datetime64[ms]')
+        self.reader.spacecrafts_orbital = {25: 'tiros n'}
+        self.reader.spacecrafts_names = {25: 'tirosn'}
+        self.reader.spacecraft_id = 25
+        self.reader.times = self.reader.to_datetime(self.reader.utcs)
+        expected_sat_azi = np.array(
+            [-76.90, 11.08, 145.33, -50.01])[:, np.newaxis]
+        expected_sun_azi = np.array(
+            [-120.36, -31.94, -173.51, -93.67])[:, np.newaxis]
+        expected_sat_zenith = np.array(
+            [69.05, 69.04, 69.55, 69.07])[:, np.newaxis]
+        expected_sun_zenith = np.array(
+            [104.30, 116.94, 94.86, 112.60])[:, np.newaxis]
+        expected_rel_azi = np.array(
+            [43.45, 43.01, 41.16, 43.65])[:, np.newaxis]
+
+        retv = self.reader.get_angles()
+        (sat_azi, sat_zenith, sun_azi, sun_zenith, rel_azi) = retv
+        np.testing.assert_allclose(sat_azi, expected_sat_azi, rtol=0.05)
+        np.testing.assert_allclose(sun_azi, expected_sun_azi, rtol=0.05)
+        np.testing.assert_allclose(sat_zenith, expected_sat_zenith, rtol=0.05)
+        np.testing.assert_allclose(sun_zenith, expected_sun_zenith, rtol=0.05)
+        np.testing.assert_allclose(rel_azi, expected_rel_azi, rtol=0.05)
+
     @mock.patch('pygac.gac_reader.ConfigParser.ConfigParser.read')
     @mock.patch('pygac.gac_reader.ConfigParser.ConfigParser.items')
     def test_get_tle_file(self, items, *mocks):
+        """Test get_tle_file."""
         # Use TLE name/dir from config file
         items.return_value = [('tledir', 'a'), ('tlename', 'b')]
         tle_file = self.reader.get_tle_file()