diff --git a/oops/backplane/limb.py b/oops/backplane/limb.py
index c7817574..a04d61b0 100755
--- a/oops/backplane/limb.py
+++ b/oops/backplane/limb.py
@@ -30,7 +30,7 @@ def limb_altitude(self, event_key, zmin=None, zmax=None, scaled=False):
         radius = body.surface.radii.max()
         if zmin is not None:
             zmin = zmin * radius
-        if zmin is not None:
+        if zmax is not None:
             zmax = zmax * radius
 
     key = ('limb_altitude', event_key, zmin, zmax)
@@ -159,7 +159,7 @@ def limb_latitude(self, event_key, lat_type='centric'):
     return self.register_backplane(key, latitude)
 
 #===============================================================================
-def limb_clock_angle(self, event_key):
+def limb_clock_angle(self, event_key, zmin=None, zmax=None, scaled=False):
     """Angular location around the limb, measured clockwise from the projected
     north pole.
 
@@ -168,8 +168,16 @@ def limb_clock_angle(self, event_key):
                         limb_altitude backplane key, in which case this
                         backplane inherits the mask of the given backplane
                         array.
+        zmin            lower limit on altitude; lower values are masked.
+        zmax            upper limit on altitude.
+        scaled          if True, zmin and zmax are in units of the maximum body radius.
     """
 
+    # Get the altitude backplane
+    altitude_key = ('limb_altitude', event_key, zmin, zmax)
+    altitude = limb_altitude(self, event_key, zmin=zmin, zmax=zmax, scaled=scaled)
+
+    # Create the clock angle backplane
     (event_key,
      backplane_key) = self._event_and_backplane_keys(event_key, LIMB_BACKPLANES,
                                                      default='LIMB')
@@ -194,8 +202,13 @@ def limb_clock_angle(self, event_key):
     event = polar_surface.apply_coords_to_event(event, obs=self.obs_event,
                                                        axes=2,
                                                        derivs=self.ALL_DERIVS)
+    clock_angle = event.coord2
+
+    # copy altitude mask
+    if np.any(altitude.mask):
+        clock_angle = clock_angle.remask_or(altitude.mask)
 
-    return self.register_backplane(key, event.coord2)
+    return self.register_backplane(key, clock_angle)
 
 ################################################################################
 
diff --git a/oops/hosts/galileo/ssi/__init__.py b/oops/hosts/galileo/ssi/__init__.py
index f1b34dac..3a9ca054 100755
--- a/oops/hosts/galileo/ssi/__init__.py
+++ b/oops/hosts/galileo/ssi/__init__.py
@@ -11,7 +11,6 @@
 import pdsparser
 import oops
 
-from oops.hosts         import pds3
 from oops.hosts.galileo import Galileo
 
 from filecache import FCPath
@@ -42,7 +41,7 @@ def from_file(filespec,
     filespec = FCPath(filespec)
 
     # Load the PDS label
-    label = pds3.get_label(filespec)
+    label = pdsparser.PdsLabel.from_file(filespec).as_dict()
 
     # Load the data array
     local_path = filespec.retrieve()
@@ -211,6 +210,8 @@ def __init__(self, meta_dict):
         self.target = meta_dict['TARGET_NAME']
 
         # Telemetry mode
+        if 'TELEMETRY_FORMAT_ID' not in meta_dict:
+            meta_dict['TELEMETRY_FORMAT_ID'] = 'NONE'
         self.mode = meta_dict['TELEMETRY_FORMAT_ID']
 
         # Window
@@ -366,9 +367,12 @@ def initialize(planets=None, asof=None,
         SSI.fovs['HCM'] = fov_full      # Inference based on inspection
                                         # hmmm, actually C0248807700R.img is 800x200
                                         # maybe this is just a cropped full fov
+        SSI.fovs['NONE'] = fov_full     # Inference based on inspection
 
         # Construct the SpiceFrame
-        _ = oops.frame.SpiceFrame("GLL_SCAN_PLATFORM")
+        # SSI images are spaced as closely as 1 unit in the file name, which
+        # corresponds to 80 clock ticks.  Therefore, we use a tolerance of +/-40
+        _ = oops.frame.SpiceType1Frame("GLL_SCAN_PLATFORM", -77, 40)
 
         # Load kernels
         Galileo.load_kernels()