Drop beam dimension

echopype/calibrate/calibrate_ek.py

@@ -124,9 +124,12 @@ def _cal_power_samples(self, cal_type: str) -> xr.Dataset:
         if "time1" in out.coords:
             out = out.drop("time1")
 
-        # Squeeze out the beam dim
-        # doing it here because both out and self.cal_params["equivalent_beam_angle"] has beam dim
-        return out.squeeze("beam", drop=True)
+        # Squeeze out the beam dim, if present.
+        # Doing it here because both out and self.cal_params["equivalent_beam_angle"] have` beam dim
+        if "beam" in out.dims:
+            return out.squeeze("beam", drop=True)
+        else:
+            return out
 
 
 class CalibrateEK60(CalibrateEK):

echopype/convert/set_groups_ek60.py

@@ -24,14 +24,16 @@ class SetGroupsEK60(SetGroupsBase):
     # in converting from v0.5.x to v0.6.0. The values within
     # these sets are applied to all Sonar/Beam_groupX groups.
 
+    # 2023-05-25 note: We have decided to remove the beam dimension from EK60,
+    # where it was added as a length-1 dimension only to more closely match
+    # the SONAR-netCDF4 v1 convention. For the time being, we are retaining the
+    # infrastructure that adds this dimension, but updating the variables lists.
+
     # Variables that need only the beam dimension added to them.
-    beam_only_names = {"backscatter_r", "angle_athwartship", "angle_alongship"}
+    beam_only_names = set()
 
     # Variables that need only the ping_time dimension added to them.
-    ping_time_only_names = {"beam_type"}
-
-    # Variables that need beam and ping_time dimensions added to them.
-    beam_ping_time_names = {
+    ping_time_only_names = {
         "beam_direction_x",
         "beam_direction_y",
         "beam_direction_z",
@@ -45,6 +47,9 @@ class SetGroupsEK60(SetGroupsBase):
         "gain_correction",
     }
 
+    # Variables that need beam and ping_time dimensions added to them.
+    beam_ping_time_names = set()
+
     beamgroups_possible = [
         {
             "name": "Beam_group1",