Merge pull request #2639 from fwfichtner/avhrr-cloud-flags

Update AVHRR EPS reader to read cloud flags information

satpy/etc/readers/avhrr_l1b_eps.yaml

@@ -89,6 +89,7 @@ datasets:
             - latitude
         file_type: avhrr_eps
 
+
     latitude:
         name: latitude
         resolution: 1050
@@ -131,6 +132,13 @@ datasets:
         coordinates: [longitude, latitude]
         file_type: avhrr_eps
 
+    cloud_flags:
+        name: cloud_flags
+        sensor: avhrr-3
+        resolution: 1050
+        coordinates: [longitude, latitude]
+        file_type: avhrr_eps
+
 file_types:
     avhrr_eps:
         file_reader: !!python/name:satpy.readers.eps_l1b.EPSAVHRRFile

satpy/readers/eps_l1b.py

@@ -287,19 +287,9 @@ def get_dataset(self, key, info):
         if self.sections is None:
             self._read_all()
 
-        if key["name"] in ["longitude", "latitude"]:
-            lons, lats = self.get_full_lonlats()
-            if key["name"] == "longitude":
-                dataset = create_xarray(lons)
-            else:
-                dataset = create_xarray(lats)
-
-        elif key["name"] in ["solar_zenith_angle", "solar_azimuth_angle",
-                             "satellite_zenith_angle", "satellite_azimuth_angle"]:
-            dataset = self._get_angle_dataarray(key)
-        elif key["name"] in ["1", "2", "3a", "3A", "3b", "3B", "4", "5"]:
-            dataset = self._get_calibrated_dataarray(key)
-        else:
+        try:
+            dataset = self._get_data_array(key)
+        except KeyError:
             logger.info("Can't load channel in eps_l1b: " + str(key["name"]))
             return
 
@@ -311,18 +301,32 @@ def get_dataset(self, key, info):
         dataset.attrs.update(key.to_dict())
         return dataset
 
+    def _get_data_array(self, key):
+        name = key["name"]
+        if name in ["longitude", "latitude"]:
+            data = self.get_full_lonlats()[int(name == "latitude")]
+            dataset = create_xarray(data)
+        elif name in ["solar_zenith_angle", "solar_azimuth_angle", "satellite_zenith_angle", "satellite_azimuth_angle"]:
+            dataset = self._get_angle_dataarray(key)
+        elif name in ["1", "2", "3a", "3A", "3b", "3B", "4", "5"]:
+            dataset = self._get_calibrated_dataarray(key)
+        elif name == "cloud_flags":
+            array = self["CLOUD_INFORMATION"]
+            dataset = create_xarray(array)
+        else:
+            raise KeyError(f"Unknown channel: {name}")
+        return dataset
+
     def _get_angle_dataarray(self, key):
         """Get an angle dataarray."""
-        sun_azi, sun_zen, sat_azi, sat_zen = self.get_full_angles()
-        if key["name"] == "solar_zenith_angle":
-            dataset = create_xarray(sun_zen)
-        elif key["name"] == "solar_azimuth_angle":
-            dataset = create_xarray(sun_azi)
-        if key["name"] == "satellite_zenith_angle":
-            dataset = create_xarray(sat_zen)
-        elif key["name"] == "satellite_azimuth_angle":
-            dataset = create_xarray(sat_azi)
-        return dataset
+        arr_index = {
+            "solar_azimuth_angle": 0,
+            "solar_zenith_angle": 1,
+            "satellite_azimuth_angle": 2,
+            "satellite_zenith_angle": 3,
+        }[key["name"]]
+        data = self.get_full_angles()[arr_index]
+        return create_xarray(data)
 
     @cached_property
     def three_a_mask(self):

satpy/tests/reader_tests/test_eps_l1b.py

@@ -152,6 +152,15 @@ def test_angles(self):
         assert res.attrs["sensor"] == "avhrr-3"
         assert res.attrs["name"] == "solar_zenith_angle"
 
+    def test_clould_flags(self):
+        """Test getting the cloud flags."""
+        did = make_dataid(name="cloud_flags")
+        res = self.fh.get_dataset(did, {})
+        assert isinstance(res, xr.DataArray)
+        assert res.attrs["platform_name"] == "Metop-C"
+        assert res.attrs["sensor"] == "avhrr-3"
+        assert res.attrs["name"] == "cloud_flags"
+
     @mock.patch("satpy.readers.eps_l1b.EPSAVHRRFile.__getitem__")
     def test_get_full_angles_twice(self, mock__getitem__):
         """Test get full angles twice."""