diff --git a/info.limpet.test/src/info/limpet/data2/TestBistaticAngleCalculations.java b/info.limpet.test/src/info/limpet/data2/TestBistaticAngleCalculations.java
index b6edc4c2..e78c4042 100644
--- a/info.limpet.test/src/info/limpet/data2/TestBistaticAngleCalculations.java
+++ b/info.limpet.test/src/info/limpet/data2/TestBistaticAngleCalculations.java
@@ -237,6 +237,19 @@ public void testCreateActions() throws IOException
 
     assertEquals("new datasets generated", 6, store.size());
 
+    // check the new datasets know about their predecessors
+    List<Document<?>> newOut = actions.get(0).getOutputs();
+    assertEquals("three outputs", 3, newOut.size());
+
+    // check they're all angles
+    for (Document<?> t : newOut)
+    {
+      NumberDocument output = (NumberDocument) t;
+      assertEquals("all in degrees", SampleData.DEGREE_ANGLE, output.getUnits());
+      assertEquals("time-related", SampleData.MILLIS, output.getIndexUnits());
+      assertNotNull("output knows where it came from", output.getPrecedent());
+    }
+
   }
 
   @Test
diff --git a/info.limpet/src/info/limpet/operations/spatial/msa/BistaticAngleOperation.java b/info.limpet/src/info/limpet/operations/spatial/msa/BistaticAngleOperation.java
index 9b99a185..96f69a1a 100644
--- a/info.limpet/src/info/limpet/operations/spatial/msa/BistaticAngleOperation.java
+++ b/info.limpet/src/info/limpet/operations/spatial/msa/BistaticAngleOperation.java
@@ -64,8 +64,7 @@ public BistaticAngleCommand(final List<IStoreItem> selection,
     {
       super("Bistatic angle at:" + target.getName() + " from "
           + tx.getName() + " to:" + rx.getName(),
-          "Calculate bistatic angle at:" + target.getName() + " from "
-              + tx.getName() + " to:" + rx.getName(), store, false, false,
+          "Calculate bistatic angles", store, false, false,
           selection, context);
 
       // special processing.
@@ -81,13 +80,13 @@ public BistaticAngleCommand(final List<IStoreItem> selection,
           _timeProvider == null ? null : SampleData.MILLIS;
       _azimuthBuilder =
           new NumberDocumentBuilder("Aximuth Angle at:" + target.getName(),
-              _outputUnits, null, indexUnits);
+              _outputUnits, this, indexUnits);
       _bistaticBuilder =
           new NumberDocumentBuilder("Bistatic Angle at:" + target.getName(),
-              _outputUnits, null, indexUnits);
+              _outputUnits, this, indexUnits);
       _bistaticAspectBuilder =
           new NumberDocumentBuilder("Bistatic Aspect Angle at:"
-              + target.getName(), _outputUnits, null, indexUnits);
+              + target.getName(), _outputUnits, this, indexUnits);
     }
 
     @Override