Updated BUFRVariables with scales and descriptions

* Added detailed descriptions with references to the attributes in BUFRVariables
* Change the attribute order to align with the exported schema
* Changed variable roundings to align with the scales defined in the BUFR schemas:
  * Latitude and longitude is set to 5. Was 6
  * heightOfStationGroundAboveMeanSeaLevel is set to 1. Was 2
  * heightOfBarometerAboveMeanSeaLevel is set to to 1. Was 2
  * pressure is set to -1. Was 1. Note: The BUFRVariable unit is Pa and not hPA
  * airTemperature is set to 2. Was 1.
  * heightOfSensorAboveLocalGroundOrDeckOfMarinePlatformTempRH is set to 2. Was 4
  * heightOfSensorAboveLocalGroundOrDeckOfMarinePlatformWSPD is set to 2. Was 4
 * Added unit tests to test the roundings
* Updated existing unit tests to align with corrected precision

src/pypromice/postprocess/bufr_utilities.py

@@ -66,28 +66,81 @@ class BUFRVariables:
 
     """
 
-    wmo_id: str
+    # Station type: "mobile" or "land"
+    # ===============================
+    # Fixed land station schema: https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_D/307080
+    # Mobile station schema: https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_D/307090
+
     station_type: str
+
+    # WMO station identifier
+    # Land stations: https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_D/301090
+    # Mobile stations: https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_D/301092
+    # ======================================================================================================
+    wmo_id: str
     timestamp: datetime.datetime
-    relativeHumidity: float = attrs.field(converter=round_converter(0))
-    airTemperature: float = attrs.field(converter=round_converter(1))
-    pressure: float = attrs.field(converter=round_converter(1))
-    windDirection: float = attrs.field(converter=round_converter(0))
-    windSpeed: float = attrs.field(converter=round_converter(1))
-    latitude: float = attrs.field(converter=round_converter(6))
-    longitude: float = attrs.field(converter=round_converter(6))
+
+    # https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_B/005001
+    # Scale: 5, unit: degrees
+    # TODO: Test if eccodes does the rounding as well. The rounding is was 6 which is larger that the scale.
+    latitude: float = attrs.field(converter=round_converter(5))
+    # https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_B/006001
+    # Scale: 5, unit: degrees
+    longitude: float = attrs.field(converter=round_converter(5))
+
+    # https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_B/007030
+    # Scale: 1, unit: m
     heightOfStationGroundAboveMeanSeaLevel: float = attrs.field(
-        converter=round_converter(2)
+        converter=round_converter(1)
     )
-    #
+    # https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_B/007031
+    # Scale: 1, unit: m
     heightOfBarometerAboveMeanSeaLevel: float = attrs.field(
-        converter=round_converter(2),
+        converter=round_converter(1),
     )
+
+    # Pressure information
+    # ====================
+    # Definition table: https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_D/302031
+    # https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_B/007004
+    # Scale: -1, unit: Pa
+    pressure: float = attrs.field(converter=round_converter(-1))
+    # There are two other pressure variables in the template: 302001 and 010062.
+
+    # Basic synoptic "instantaneous" data
+    # ===================================
+    # Definition table: https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_D/302035
+    # This section only include the temperature and humidity data (302032).
+    # Precipitation and cloud data are currently ignored.
+    # https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_B/007032
+    # Scale: 2, unit: m
+    # This is the first appearance of this variable id.
     heightOfSensorAboveLocalGroundOrDeckOfMarinePlatformTempRH: float = attrs.field(
-        converter=round_converter(4),
+        converter=round_converter(2),
     )
+    # https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_B/012101
+    # Scale: 2, unit: K
+    airTemperature: float = attrs.field(converter=round_converter(2))
+    # There is also a Dewpoint temperature in this template: 012103 which is currently unused.
+    # https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_B/012103
+    # Scale: 0, unit: %
+    relativeHumidity: float = attrs.field(converter=round_converter(0))
+
+    # Basic synoptic "period" data
+    # ============================
+    # Definition table: https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_D/302043
+    # Wind data: https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_D/302042
+    # Wind direction: https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_B/011001
+    # Scale: 0, unit: degrees
+    windDirection: float = attrs.field(converter=round_converter(0))
+    # Wind speed: https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_B/011002
+    # Scale: 1, unit: m/s
+    windSpeed: float = attrs.field(converter=round_converter(1))
+    # https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_B/007032
+    # Scale: 2, unit: m
+    # This is the 7th appearance of this variable id.
     heightOfSensorAboveLocalGroundOrDeckOfMarinePlatformWSPD: float = attrs.field(
-        converter=round_converter(4)
+        converter=round_converter(2)
     )
 
     def as_series(self) -> pd.Series:
@@ -131,6 +184,7 @@ def __eq__(self, other: "BUFRVariables"):
 
 BUFR_TEMPLATES = {
     "mobile": {
+        # Template definition: https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_D/307090
         "unexpandedDescriptors": (307090),  # message template, "synopMobil"
         "edition": 4,  # latest edition
         "masterTableNumber": 0,
@@ -146,6 +200,7 @@ def __eq__(self, other: "BUFRVariables"):
         "compressedData": 0,
     },
     "land": {
+        # Template definition: https://vocabulary-manager.eumetsat.int/vocabularies/BUFR/WMO/32/TABLE_D/307080
         "unexpandedDescriptors": (307080),  # message template, "synopLand"
         "edition": 4,  # latest edition
         "masterTableNumber": 0,

tests/unit/bufr_export/test_bufr_utilitites.py

@@ -181,3 +181,37 @@ def test_nan_value_serialization(self):
             variables_src,
             variables_read,
         )
+
+    def test_precision(self):
+        """
+        Test if the BUFRVariable rounding configurations aligns with the BUFR format.
+
+        Use np.random.random() to generate high precision random values.
+        """
+        variables_src = BUFRVariables(
+            wmo_id="04464",
+            station_type="mobile",
+            timestamp=datetime.datetime(2023, 12, 19, 10, 0),
+            relativeHumidity=np.random.random(),
+            airTemperature=np.random.random(),
+            pressure=1000*np.random.random(),
+            windDirection=np.random.random(),
+            windSpeed=np.random.random(),
+            latitude=np.random.random(),
+            longitude=np.random.random(),
+            heightOfStationGroundAboveMeanSeaLevel=np.random.random(),
+            heightOfBarometerAboveMeanSeaLevel=np.random.random(),
+            heightOfSensorAboveLocalGroundOrDeckOfMarinePlatformTempRH=np.random.random(),
+            heightOfSensorAboveLocalGroundOrDeckOfMarinePlatformWSPD=np.random.random(),
+        )
+        with tempfile.TemporaryFile("w+b") as fp:
+            write_bufr_message(variables=variables_src, file=fp)
+            fp.seek(0)
+            variables_read = read_bufr_message(
+                fp=fp,
+            )
+
+        self.assertEqual(
+            variables_src,
+            variables_read,
+        )

tests/unit/bufr_export/test_create_bufr_files.py

@@ -32,7 +32,7 @@ def tearDown(self):
 
     def test_create_bufr_files(self):
         """
-        Teste the creation of bufr files and their output folder structure.
+        Test the creation of bufr files and their output folder structure.
         It does not test the content of the bufr files.
         """
         input_dir = self.temp_dir / "input"

tests/unit/bufr_export/test_get_bufr.py

@@ -54,7 +54,7 @@ def test_bufr_variables_gcnet(self):
             stid=station_configuration.stid,
             station_configuration=station_configuration,
             relativeHumidity=69.0,
-            airTemperature=256.0,
+            airTemperature=255.95,
             pressure=77300.0,
             windDirection=149.0,
             windSpeed=14.9,
@@ -84,7 +84,7 @@ def test_bufr_variables_promice_v2(self):
             stid=station_configuration.stid,
             station_configuration=station_configuration,
             relativeHumidity=69.0,
-            airTemperature=256.0,
+            airTemperature=255.95,
             pressure=77300.0,
             windDirection=149.0,
             windSpeed=14.9,
@@ -114,7 +114,7 @@ def test_bufr_variables_promice_v3(self):
             stid=station_configuration.stid,
             station_configuration=station_configuration,
             relativeHumidity=69.0,
-            airTemperature=256.0,
+            airTemperature=255.95,
             pressure=77300.0,
             windDirection=149.0,
             windSpeed=14.9,
@@ -165,7 +165,7 @@ def test_bufr_variables_static_gps_elevation(self):
             station_type=station_config.station_type,
             timestamp=timestamp,
             relativeHumidity=1.0,
-            airTemperature=252.2,  # Converted to kelvin
+            airTemperature=252.15,  # Converted to kelvin
             pressure=199300.0,
             windDirection=32.0,
             windSpeed=5.3,

tests/unit/bufr_export/test_get_bufr_integration.py

@@ -141,7 +141,7 @@ def test_get_bufr_has_new_data(self):
             # Newest measurement in tx_l3_test1.csv: 2023-12-07 23:00:00
             timestamp=datetime.datetime(2023, 12, 7, 23, 00),
             relativeHumidity=69,
-            airTemperature=256.0,
+            airTemperature=255.95,
             pressure=77300.0,
             windDirection=149,
             windSpeed=14.9,
@@ -180,7 +180,7 @@ def test_get_bufr_has_new_data_dont_store_position(self):
             # Newest measurement in tx_l3_test1.csv: 2023-12-07 23:00:00
             timestamp=datetime.datetime(2023, 12, 7, 23, 00),
             relativeHumidity=69,
-            airTemperature=256.0,
+            airTemperature=255.95,
             pressure=77300.0,
             windDirection=149,
             windSpeed=14.9,
@@ -260,7 +260,7 @@ def test_get_bufr_includes_datasets_not_in_latests_timestamps(self):
             # Newest measurement in tx_l3_test1.csv: 2023-12-07 23:00:00
             timestamp=datetime.datetime(2023, 12, 7, 23, 00),
             relativeHumidity=69,
-            airTemperature=256.0,
+            airTemperature=255.95,
             pressure=77300.0,
             windDirection=149,
             windSpeed=14.9,
@@ -321,7 +321,7 @@ def test_invalid_value_at_last_index(self):
             # Newest measurement in tx_l3_test1.csv: 2023-12-07 23:00:00
             timestamp=datetime.datetime(2023, 12, 7, 23, 00),
             relativeHumidity=69,
-            airTemperature=256.0,
+            airTemperature=255.95,
             pressure=np.nan,
             windDirection=149,
             windSpeed=14.9,
@@ -459,7 +459,7 @@ def test_ignore_newer_data_than_now_input(self):
             # Newest measurement in tx_l3_test1.csv: 2023-12-07 23:00:00 but now_timestamp is 2023-12-06
             timestamp=datetime.datetime(2023, 12, 6, 0, 0),
             relativeHumidity=82,
-            airTemperature=250.8,
+            airTemperature=250.85,
             pressure=77370.0,
             windDirection=153,
             windSpeed=10.4,
@@ -500,7 +500,7 @@ def test_land_station_export(self):
             # Newest measurement in tx_l3_test1.csv: 2023-12-07 23:00:00
             timestamp=datetime.datetime(2023, 12, 7, 23, 00),
             relativeHumidity=69,
-            airTemperature=256.0,
+            airTemperature=255.95,
             pressure=77300.0,
             windDirection=149,
             windSpeed=14.9,