Merge pull request #1706 from simonrp84/slstr

Update SLSTR reader to choose correct file for interpolated angles

satpy/readers/slstr_l1b.py

@@ -231,6 +231,15 @@ def end_time(self):
 class NCSLSTRAngles(BaseFileHandler):
     """Filehandler for angles."""
 
+    def _loadcart(self, fname):
+        """Load a cartesian file of appropriate type."""
+        cartf = xr.open_dataset(fname,
+                                decode_cf=True,
+                                mask_and_scale=True,
+                                chunks={'columns': CHUNK_SIZE,
+                                        'rows': CHUNK_SIZE})
+        return cartf
+
     def __init__(self, filename, filename_info, filetype_info):
         """Initialize the angles reader."""
         super(NCSLSTRAngles, self).__init__(filename, filename_info,
@@ -245,29 +254,23 @@ def __init__(self, filename, filename_info, filetype_info):
         # TODO: get metadata from the manifest file (xfdumanifest.xml)
         self.platform_name = PLATFORM_NAMES[filename_info['mission_id']]
         self.sensor = 'slstr'
-
         self.view = filename_info['view']
         self._start_time = filename_info['start_time']
         self._end_time = filename_info['end_time']
 
-        cart_file = os.path.join(
+        carta_file = os.path.join(
+            os.path.dirname(self.filename), 'cartesian_a{}.nc'.format(self.view[0]))
+        carti_file = os.path.join(
             os.path.dirname(self.filename), 'cartesian_i{}.nc'.format(self.view[0]))
-        self.cart = xr.open_dataset(cart_file,
-                                    decode_cf=True,
-                                    mask_and_scale=True,
-                                    chunks={'columns': CHUNK_SIZE,
-                                            'rows': CHUNK_SIZE})
         cartx_file = os.path.join(
             os.path.dirname(self.filename), 'cartesian_tx.nc')
-        self.cartx = xr.open_dataset(cartx_file,
-                                     decode_cf=True,
-                                     mask_and_scale=True,
-                                     chunks={'columns': CHUNK_SIZE,
-                                             'rows': CHUNK_SIZE})
+        self.carta = self._loadcart(carta_file)
+        self.carti = self._loadcart(carti_file)
+        self.cartx = self._loadcart(cartx_file)
 
     def get_dataset(self, key, info):
         """Load a dataset."""
-        if not info['view'].name.startswith(self.view):
+        if not key['view'].name.startswith(self.view[0]):
             return
         logger.debug('Reading %s.', key['name'])
         # Check if file_key is specified in the yaml
@@ -283,15 +286,19 @@ def get_dataset(self, key, info):
 
         if c_step != 1 or l_step != 1:
             logger.debug('Interpolating %s.', key['name'])
-
             # TODO: do it in cartesian coordinates ! pbs at date line and
             # possible
             tie_x = self.cartx['x_tx'].data[0, :][::-1]
             tie_y = self.cartx['y_tx'].data[:, 0]
-            full_x = self.cart['x_i' + self.view[0]].data
-            full_y = self.cart['y_i' + self.view[0]].data
+            if key.get('resolution', 1000) == 500:
+                full_x = self.carta['x_a' + self.view[0]].data
+                full_y = self.carta['y_a' + self.view[0]].data
+            else:
+                full_x = self.carti['x_i' + self.view[0]].data
+                full_y = self.carti['y_i' + self.view[0]].data
 
             variable = variable.fillna(0)
+            variable.attrs['resolution'] = key.get('resolution', 1000)
 
             from scipy.interpolate import RectBivariateSpline
             spl = RectBivariateSpline(

satpy/tests/reader_tests/test_slstr_l1b.py

@@ -93,6 +93,15 @@ def setUp(self, xr_):
                 'S9_BT_ao': self.rad,
                 'foo_radiance_an': self.rad,
                 'S5_solar_irradiances': self.rad,
+                'geometry_tn': self.rad,
+                'latitude_an': self.rad,
+                'x_tx': self.rad,
+                'y_tx': self.rad,
+                'x_in': self.rad,
+                'y_in': self.rad,
+                'x_an': self.rad,
+                'y_an': self.rad,
+                'flags_an': self.rad,
                 'detector_an': det,
             },
             attrs={
@@ -110,9 +119,19 @@ def make_dataid(**items):
 class TestSLSTRReader(TestSLSTRL1B):
     """Test various nc_slstr file handlers."""
 
+    class FakeSpl:
+        """Fake return function for SPL interpolation."""
+
+        @staticmethod
+        def ev(foo_x, foo_y):
+            """Fake function to return interpolated data."""
+            return np.zeros((3, 2))
+
     @mock.patch('satpy.readers.slstr_l1b.xr')
-    def test_instantiate(self, xr_):
+    @mock.patch('scipy.interpolate.RectBivariateSpline')
+    def test_instantiate(self, bvs_, xr_):
         """Test initialization of file handlers."""
+        bvs_.return_value = self.FakeSpl
         xr_.open_dataset.return_value = self.fake_dataset
 
         good_start = datetime.strptime(self.start_time,
@@ -122,6 +141,8 @@ def test_instantiate(self, xr_):
 
         ds_id = make_dataid(name='foo', calibration='radiance',
                             stripe='a', view='nadir')
+        ds_id_500 = make_dataid(name='foo', calibration='radiance',
+                                stripe='a', view='nadir', resolution=500)
         filename_info = {'mission_id': 'S3A', 'dataset_name': 'foo',
                          'start_time': 0, 'end_time': 0,
                          'stripe': 'a', 'view': 'n'}
@@ -149,28 +170,29 @@ def test_instantiate(self, xr_):
         filename_info = {'mission_id': 'S3A', 'dataset_name': 'foo',
                          'start_time': 0, 'end_time': 0,
                          'stripe': 'a', 'view': 'n'}
-        test = NCSLSTRGeo('somedir/S1_radiance_an.nc', filename_info, 'c')
-        test.get_dataset(ds_id, dict(filename_info, **{'file_key': 'foo'}))
+        test = NCSLSTRGeo('somedir/geometry_an.nc', filename_info, 'c')
+        test.get_dataset(ds_id, dict(filename_info, **{'file_key': 'latitude_{stripe:1s}{view:1s}'}))
         self.assertEqual(test.start_time, good_start)
         self.assertEqual(test.end_time, good_end)
         xr_.open_dataset.assert_called()
         xr_.open_dataset.reset_mock()
 
-        test = NCSLSTRAngles('somedir/S1_radiance_an.nc', filename_info, 'c')
-        # TODO: Make this test work
-        # test.get_dataset(ds_id, filename_info)
+        test = NCSLSTRFlag('somedir/S1_radiance_an.nc', filename_info, 'c')
+        test.get_dataset(ds_id, dict(filename_info, **{'file_key': 'flags_{stripe:1s}{view:1s}'}))
+        assert test.view == 'nadir'
+        assert test.stripe == 'a'
         self.assertEqual(test.start_time, good_start)
         self.assertEqual(test.end_time, good_end)
         xr_.open_dataset.assert_called()
         xr_.open_dataset.reset_mock()
 
-        test = NCSLSTRFlag('somedir/S1_radiance_an.nc', filename_info, 'c')
-        assert test.view == 'nadir'
-        assert test.stripe == 'a'
+        test = NCSLSTRAngles('somedir/S1_radiance_an.nc', filename_info, 'c')
+        test.get_dataset(ds_id, dict(filename_info, **{'file_key': 'geometry_t{view:1s}'}))
         self.assertEqual(test.start_time, good_start)
         self.assertEqual(test.end_time, good_end)
         xr_.open_dataset.assert_called()
         xr_.open_dataset.reset_mock()
+        test.get_dataset(ds_id_500, dict(filename_info, **{'file_key': 'geometry_t{view:1s}'}))
 
 
 class TestSLSTRCalibration(TestSLSTRL1B):