Added previous changes Josh made regarding the removal of the instruments...

Added previous changes Josh made regarding the removal of the instruments response/sensitivity. I also added some default innit function incase the user wants to override this logic as requested in the original issue.

geomagio/edge/FDSNFactory.py

@@ -280,24 +280,31 @@ class FDSNFactory(TimeseriesFactory):
                 trace=data[0], starttime=starttime, endtime=endtime
             )
 
-        if self.remove_sensitivity is not None:
-            if self.remove_sensitivity_flag == "remove_sensitivity":
-                data[0].remove_sensitivity()
+        for trace in data:
+            response = trace.stats.response
+            if self.remove_sensitivity is not None:
+                if self.remove_sensitivity_flag == "remove_sensitivity":
+                    trace.remove_sensitivity()
 
-            elif self.remove_sensitivity_flag == "remove_response":
-                data[0].remove_response(output="DEF", zero_mean=False, taper=False)
-
-        else:
-            # If the instrument_sensitivity exists, remove the sensitivity
-            if hasattr(data[0].stats.response, "instrument_sensitivity"):
-                data[0].remove_sensitivity()
+                elif self.remove_sensitivity_flag == "remove_response":
+                    trace.remove_response()
 
             else:
-                data[0].remove_response(output="DEF", zero_mean=False, taper=False)
-
-        if data[0].stats.response.instrument_sensitivity.input_units == "T":
-            # convert to nT (nanoteslas) if units are "T" (Teslas)
-            data[0].data *= 1e9
+                if response.instrument_sensitivity:
+                    if response.instrument_sensitivity.input_units == "T":
+                        # some ASL stations produce data in Teslas, not nanoteslas
+                        response.instrument_sensitivity.value /= 1e9
+                        response.instrument_sensitivity.input_units = "nT"
+                    # apply total gain/sensitivity, ignore any frequency response
+                    trace.remove_sensitivity()
+                else:
+                    # according to fdsn docs, if no instrument_sensitivity,
+                    # the response must be an instrument_polynomial
+                    # https://docs.fdsn.org/projects/stationxml/en/latest/reference.html#instrumentsensitivity
+
+                    # Geomag Program observatories use 2nd order instrument_polynomial
+                    # to capture both offset and scale, but no frequency response
+                    data.remove_response()
 
         else:
             self._set_metadata(data, observatory, channel, type, interval)