Updated get_bufr to support static GPS heights.

* Bedrock stations shouldn’t depend on the noisy GPS signal for elevation.
* Added station dimension values for WEG_B
* Added corresponding unittest

src/pypromice/postprocess/get_bufr.py

@@ -144,6 +144,7 @@ class StationConfiguration:
     temperature_from_sonic_ranger: Optional[float] = None
     height_of_gps_from_station_ground: Optional[float] = None
     sonic_ranger_from_gps: Optional[float] = None
+    static_height_of_gps_from_mean_sea_level: Optional[float] = None
 
     # The station data will be exported to BUFR if True. Otherwise, it will only export latest position
     export_bufr: bool = False
@@ -558,14 +559,22 @@ def get_bufr_variables(
     if station_configuration.barometer_from_gps is None:
         raise AttributeError("barometer_from_gps is required for BUFR export")
 
+    if station_configuration.static_height_of_gps_from_mean_sea_level is None:
+        height_of_gps_above_mean_sea_level = data["gps_alt_fit"]
+    else:
+        height_of_gps_above_mean_sea_level = (
+            station_configuration.static_height_of_gps_from_mean_sea_level
+        )
+
     heightOfStationGroundAboveMeanSeaLevel = (
-        data["gps_alt_fit"] - station_configuration.height_of_gps_from_station_ground
+        height_of_gps_above_mean_sea_level - station_configuration.height_of_gps_from_station_ground
     )
 
     heightOfBarometerAboveMeanSeaLevel = (
-        data["gps_alt_fit"] + station_configuration.barometer_from_gps
+        height_of_gps_above_mean_sea_level + station_configuration.barometer_from_gps
     )
 
+
     heightOfSensorAboveLocalGroundOrDeckOfMarinePlatformTempRH = (
         station_configuration.temperature_from_station_ground
     )

src/pypromice/postprocess/station_configurations.toml

@@ -514,6 +514,12 @@ station_site = "NUK_U"
 project = "Wegener"
 station_type = "land"
 wmo_id = "460"
+barometer_from_gps = 1.3
+anemometer_from_sonic_ranger = 0.4
+temperature_from_sonic_ranger = 0.0
+height_of_gps_from_station_ground = 0.9
+sonic_ranger_from_gps = 1.3
+static_height_of_gps_from_mean_sea_level = 17.5
 export_bufr = true
 skipped_variables = []
 positions_update_timestamp_only = false

src/pypromice/test/bufr_export/test_get_bufr.py

@@ -199,6 +199,68 @@ def test_bufr_variables_promice_v3(self):
             heightOfBarometerAboveMeanSeaLevel=2126,
         )
 
+    def test_bufr_variables_static_gps_elevation(self):
+        timestamp = datetime.datetime.now()
+        data = pd.Series(
+            data=dict(
+                rh_i=0.93,
+                t_i=-21,
+                name="",
+                p_i=993,
+                wdir_i=32.1,
+                wspd_i=5.3,
+                gps_lon_fit=-46.0,
+                gps_lat_fit=66.0,
+                # This is a erroneous value that should be overridden by the static value
+                gps_alt_fit=142.1,
+                z_boom_u_smooth=2.1,
+            ),
+            name=timestamp,
+        )
+        station_config = StationConfiguration(
+            stid="A_STID",
+            station_type="land",
+            wmo_id="4201",
+            export_bufr=True,
+            barometer_from_gps=1.3,
+            height_of_gps_from_station_ground=0.9,
+            static_height_of_gps_from_mean_sea_level=17.5,
+            anemometer_from_sonic_ranger=None,
+            temperature_from_sonic_ranger=None,
+            sonic_ranger_from_gps=None,
+        )
+        # The elevations should be determined from the static variable
+        expected_station_ground_elevation = 17.5 - 0.9
+        expected_barometer_elevation = 17.5 + 1.3
+
+        expected_bufr_variables = BUFRVariables(
+            wmo_id=station_config.wmo_id,
+            station_type=station_config.station_type,
+            timestamp=timestamp,
+            relativeHumidity=1.0,
+            airTemperature=252.2,  # Converted to kelvin
+            pressure=199300.0,
+            windDirection=32.0,
+            windSpeed=5.3,
+            latitude=66.0,
+            longitude=-46.0,
+            heightOfStationGroundAboveMeanSeaLevel=expected_station_ground_elevation,
+            heightOfBarometerAboveMeanSeaLevel=expected_barometer_elevation,
+            # The sensor heights are ignored since the necessary dimension values are missing
+            heightOfSensorAboveLocalGroundOrDeckOfMarinePlatformTempRH=np.nan,
+            heightOfSensorAboveLocalGroundOrDeckOfMarinePlatformWSPD=np.nan,
+        )
+
+        output = get_bufr_variables(
+            data,
+            station_configuration=station_config,
+        )
+
+        self.assertEqual(
+            expected_bufr_variables,
+            output,
+        )
+
     def test_fails_on_missing_dimension_values(self):
         """
         Test that get_bufr_variables raises an AttributeError if the data is missing