Merge pull request #1089 from mraspaud/fix-sunz-correction-computation

Make sunz correction use available sunz dataset

satpy/composites/__init__.py

@@ -376,7 +376,7 @@ def __init__(self, max_sza=95.0, **kwargs):
 
     def __call__(self, projectables, **info):
         """Generate the composite."""
-        projectables = self.match_data_arrays(projectables)
+        projectables = self.match_data_arrays(list(projectables) + list(info.get('optional_datasets', [])))
         vis = projectables[0]
         if vis.attrs.get("sunz_corrected"):
             LOG.debug("Sun zen correction already applied")
@@ -387,7 +387,7 @@ def __call__(self, projectables, **info):
         tic = time.time()
         LOG.debug("Applying sun zen correction")
         coszen = self.coszen.get(key)
-        if coszen is None and len(projectables) == 1:
+        if coszen is None and not info.get('optional_datasets'):
             # we were not given SZA, generate SZA then calculate cos(SZA)
             from pyorbital.astronomy import cos_zen
             LOG.debug("Computing sun zenith angles.")

satpy/tests/test_composites.py

@@ -17,13 +17,15 @@
 # satpy.  If not, see <http://www.gnu.org/licenses/>.
 """Tests for compositors in composites/__init__.py."""
 
-import xarray as xr
-import dask.array as da
-import dask
-import numpy as np
+import unittest
 from datetime import datetime
 from unittest import mock
-import unittest
+
+import dask
+import dask.array as da
+import numpy as np
+import pytest
+import xarray as xr
 
 
 class TestMatchDataArrays(unittest.TestCase):
@@ -233,6 +235,9 @@ def setUp(self):
         area = AreaDefinition('test', 'test', 'test',
                               {'proj': 'merc'}, 2, 2,
                               (-2000, -2000, 2000, 2000))
+        bigger_area = AreaDefinition('test', 'test', 'test',
+                                     {'proj': 'merc'}, 4, 4,
+                                     (-2000, -2000, 2000, 2000))
         attrs = {'area': area,
                  'start_time': datetime(2018, 1, 1, 18),
                  'modifiers': tuple(),
@@ -241,6 +246,11 @@ def setUp(self):
                            attrs=attrs, dims=('y', 'x'),
                            coords={'y': [0, 1], 'x': [0, 1]})
         self.ds1 = ds1
+        ds2 = xr.DataArray(da.ones((4, 4), chunks=2, dtype=np.float64),
+                           attrs=attrs, dims=('y', 'x'),
+                           coords={'y': [0, 0.5, 1, 1.5], 'x': [0, 0.5, 1, 1.5]})
+        ds2.attrs['area'] = bigger_area
+        self.ds2 = ds2
         self.sza = xr.DataArray(
             np.rad2deg(np.arccos(da.from_array([[0.0149581333, 0.0146694376], [0.0150812684, 0.0147925727]],
                                                chunks=2))),
@@ -284,6 +294,13 @@ def test_basic_lims_provided(self):
         res = comp((self.ds1, self.sza), test_attr='test')
         np.testing.assert_allclose(res.values, np.array([[66.853262, 68.168939], [66.30742, 67.601493]]))
 
+    def test_imcompatible_areas(self):
+        """Test sunz correction on incompatible areas."""
+        from satpy.composites import SunZenithCorrector, IncompatibleAreas
+        comp = SunZenithCorrector(name='sza_test', modifiers=tuple(), correction_limit=90)
+        with pytest.raises(IncompatibleAreas):
+            comp((self.ds2, self.sza), test_attr='test')
+
 
 class TestDifferenceCompositor(unittest.TestCase):
     """Test case for the difference compositor."""