Fix VIIRS EDR using the wrong geolocation arrays

satpy/readers/viirs_edr.py

@@ -257,6 +257,7 @@ def _dynamic_variables_from_file(self, handled_var_names: set) -> Iterable[tuple
         i_lon_name = f"longitude_i_{ftype}"
         i_lat_name = f"latitude_i_{ftype}"
         i_coords = (i_lon_name, i_lat_name)
+        coords: dict[str, dict] = {}
         for var_name in self.nc.variables.keys():
             data_arr = self.nc[var_name]
             is_lon = "longitude" in var_name.lower()
@@ -276,19 +277,28 @@ def _dynamic_variables_from_file(self, handled_var_names: set) -> Iterable[tuple
                 "resolution": res,
                 "coordinates": m_coords if res == 750 else i_coords,
             }
-            if is_lon:
-                ds_info["standard_name"] = "longitude"
-                ds_info["units"] = "degrees_east"
-                ds_info["name"] = m_lon_name if res == 750 else i_lon_name
-                # recursive coordinate/SwathDefinitions are not currently handled well in the base reader
-                del ds_info["coordinates"]
-            elif is_lat:
-                ds_info["standard_name"] = "latitude"
-                ds_info["units"] = "degrees_north"
-                ds_info["name"] = m_lat_name if res == 750 else i_lat_name
-                # recursive coordinate/SwathDefinitions are not currently handled well in the base reader
-                del ds_info["coordinates"]
-            yield True, ds_info
+            if not (is_lon or is_lat):
+                yield True, ds_info
+                continue
+
+            ds_info["standard_name"] = "longitude" if is_lon else "latitude"
+            ds_info["units"] = "degrees_east" if is_lon else "degrees_north"
+            # recursive coordinate/SwathDefinitions are not currently handled well in the base reader
+            del ds_info["coordinates"]
+            if var_name not in handled_var_names:
+                handled_var_names.add(var_name)
+                yield True, ds_info
+
+            # "standard" geolocation coordinate (assume shorter variable name is "better")
+            new_name = (m_lon_name if res == 750 else i_lon_name) if is_lon else (
+                m_lat_name if res == 750 else i_lat_name)
+            if new_name not in coords or len(var_name) < len(coords[new_name]["file_key"]):
+                ds_info = ds_info.copy()
+                ds_info["name"] = new_name
+                coords[ds_info["name"]] = ds_info
+
+        for coord_info in coords.values():
+            yield True, coord_info
 
 
 class VIIRSSurfaceReflectanceWithVIHandler(VIIRSJRRFileHandler):

satpy/tests/reader_tests/test_viirs_edr.py

@@ -213,6 +213,14 @@ def cloud_height_file(tmp_path_factory: TempPathFactory) -> Path:
     data_vars = _create_continuous_variables(
         ("CldTopTemp", "CldTopHght", "CldTopPres")
     )
+    lon_pc = data_vars["Longitude"].copy(deep=True)
+    lat_pc = data_vars["Latitude"].copy(deep=True)
+    lon_pc.attrs["long_name"] = "BAD"
+    lat_pc.attrs["long_name"] = "BAD"
+    del lon_pc.encoding["_FillValue"]
+    del lat_pc.encoding["_FillValue"]
+    data_vars["Longitude_Pc"] = lon_pc
+    data_vars["Latitude_Pc"] = lat_pc
     return _create_fake_file(tmp_path_factory, fn, data_vars)
 
 
@@ -556,6 +564,9 @@ def _shared_metadata_checks(data_arr: xr.DataArray) -> None:
     assert lons.max() <= 180.0
     assert lats.min() >= -90.0
     assert lats.max() <= 90.0
+    # Some files (ex. CloudHeight) have other lon/lats that shouldn't be used
+    assert lons.attrs.get("long_name") != "BAD"
+    assert lats.attrs.get("long_name") != "BAD"
 
     if "valid_range" in data_arr.attrs:
         valid_range = data_arr.attrs["valid_range"]