Towards uniform unit handling

- remove nT <--> T handling from inventory_review in sandbox
- replace with triage_mt_units_magnetic_field
- make triage_units a list, not a string, that can handle electrics an magnetics
- make MT2SI_MAGNETIC_FIELD_FILTER

aurora/sandbox/io_helpers/inventory_review.py

@@ -38,7 +38,9 @@ def describe_inventory_stages(inventory, assign_names=False, verbose=False):
                             new_name = f"{station.code}_{channel.code}_{i}"
                             stage.name = new_name
                             if verbose:
-                                logger.info(f"ASSIGNING stage {stage}, name {stage.name}")
+                                logger.info(
+                                    f"ASSIGNING stage {stage}, name {stage.name}"
+                                )
                     if hasattr(stage, "symmetry"):
                         pass
                         # import matplotlib.pyplot as plt
@@ -116,15 +118,17 @@ def scan_inventory_for_nonconformity(inventory, verbose=False):
                 # print("Applied unstable fix to magnetic channel names")
                 logger.info("{T1,T2,T3} --> {F1, F2, F3}")
 
-            # Tesla to nanoTesla
-            for channel in station:
-                response = channel.response
-                for stage in response.response_stages:
-                    if verbose:
-                        msg = f"{channel.code} {stage.stage_sequence_number}"
-                        msg = f"{msg} {stage.input_units}"
-                        logger.info(msg)
-                    if stage.input_units == "T":
-                        stage.input_units = "nT"
-                        stage.stage_gain *= 1e-9
+            # Below represents correct syntax for a valid, but not conventional way to correct units
+            # leaving the code (commented) for future reference
+            # # Tesla to nanoTesla
+            # for channel in station:
+            #     response = channel.response
+            #     for stage in response.response_stages:
+            #         if verbose:
+            #             msg = f"{channel.code} {stage.stage_sequence_number}"
+            #             msg = f"{msg} {stage.input_units}"
+            #             logger.info(msg)
+            #         if stage.input_units == "T":
+            #             stage.input_units = "nT"
+            #             stage.stage_gain *= 1e-9
     return inventory

aurora/sandbox/io_helpers/make_mth5_helpers.py

@@ -7,6 +7,7 @@
 from aurora.sandbox.obspy_helpers import trim_streams_to_acquisition_run
 from aurora.sandbox.triage_metadata import triage_missing_coil_hollister
 from aurora.sandbox.triage_metadata import triage_mt_units_electric_field
+from aurora.sandbox.triage_metadata import triage_mt_units_magnetic_field
 from mt_metadata.timeseries.stationxml import XMLInventoryMTExperiment
 from mth5.utils.helpers import initialize_mth5
 from mth5.timeseries import RunTS
@@ -18,7 +19,7 @@ def create_from_server_multistation(
     target_folder=Path(),
     run_id="001",
     force_align_streams=True,
-    triage_units=None,
+    triage_units=[],
     triage_missing_coil=False,
     **kwargs,
 ):
@@ -54,8 +55,10 @@ def create_from_server_multistation(
 
     # TRIAGE ONE-OFF ISSUE WITH UNITS
     if triage_units:
-        if triage_units == "V/m to mV/km":
+        if "V/m to mV/km" in triage_units:
             experiment = triage_mt_units_electric_field(experiment)
+        if "T to nT" in triage_units:
+            experiment = triage_mt_units_magnetic_field(experiment)
     if triage_missing_coil:
         experiment = triage_missing_coil_hollister(experiment)
 

aurora/sandbox/triage_metadata.py

@@ -1,4 +1,6 @@
 from aurora.time_series.filters.filter_helpers import MT2SI_ELECTRIC_FIELD_FILTER
+from aurora.time_series.filters.filter_helpers import MT2SI_MAGNETIC_FIELD_FILTER
+
 from loguru import logger
 
 
@@ -33,6 +35,37 @@ def triage_mt_units_electric_field(experiment):
     return experiment
 
 
+def triage_mt_units_magnetic_field(experiment):
+    """
+    One-off example of adding a filter to an mth5 in the case where the electric
+    field data are given in V/m, but they were expected in mV/km.  This adds the
+    correct filter to the metadata so that the calibrated data have units of
+    mV/km.
+     Parameters
+    ----------
+    experiment ;
+
+    Returns
+    -------
+
+    """
+    logger.info(
+        f"Add MT2SI_MAGNETIC_FIELD_FILTER to magnetic channels for parkfield"
+        f" {MT2SI_MAGNETIC_FIELD_FILTER} "
+    )
+    filter_name = MT2SI_MAGNETIC_FIELD_FILTER.name
+    survey = experiment.surveys[0]
+    survey.filters[filter_name] = MT2SI_MAGNETIC_FIELD_FILTER
+    stations = survey.stations
+    for station in stations:
+        channels = station.runs[0].channels
+        for channel in channels:
+            if channel.component[0] == "h":
+                channel.filter.name.insert(0, filter_name)
+                channel.filter.applied.insert(0, True)
+    return experiment
+
+
 def triage_missing_coil_hollister(experiment):
     """
     One off for hollister missing hy metadata for no reason I can tell

aurora/test_utils/parkfield/make_parkfield_mth5.py

@@ -42,7 +42,7 @@ def make_pkdsao_mth5(fdsn_dataset):
     h5_path = create_from_server_multistation(
         fdsn_dataset,
         target_folder=PARKFIELD_PATHS["data"],
-        triage_units="V/m to mV/km",
+        triage_units=["V/m to mV/km", "T to nT"],
     )
 
     for station in fdsn_dataset.station.split(","):

aurora/time_series/filters/filter_helpers.py

@@ -83,7 +83,25 @@ def make_volt_per_meter_to_millivolt_per_km_converter():
     return coeff_filter
 
 
+def make_tesla_to_nanotesla_converter():
+    """
+    This represents a filter that converts from nt to T.
+
+    Returns
+    -------
+
+    """
+    coeff_filter = make_coefficient_filter(
+        gain=1e-9,
+        units_in="nanotesla",
+        units_out="tesla",
+        name="MT to SI magnetic field conversion",
+    )
+    return coeff_filter
+
+
 MT2SI_ELECTRIC_FIELD_FILTER = make_volt_per_meter_to_millivolt_per_km_converter()
+MT2SI_MAGNETIC_FIELD_FILTER = make_tesla_to_nanotesla_converter()
 
 
 def main():