Update covariance units

lsst · Dec 9, 2022 · b73e64c · b73e64c
1 parent d1bb8a0
commit b73e64c
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Showing 3 changed files with 10 additions and 5 deletions.
diff --git a/doc/lsst.meas.algorithms/reference-catalog-schema.rst b/doc/lsst.meas.algorithms/reference-catalog-schema.rst
@@ -44,9 +44,9 @@ The following are optional; fields should only be present if the information is
     - ``parallax_flag``: set if parallax value or parallaxErr is bad
     - ``coord_ra_pm_ra_Cov``: covariance between coord_ra and pm_ra (rad^2/year)
     - ``coord_ra_pm_dec_Cov``: covariance between coord_ra and pm_dec (rad^2/year)
-    - ``coord_ra_parallax_Cov``: covariance between coord_ra and parallax (rad^2/year)
+    - ``coord_ra_parallax_Cov``: covariance between coord_ra and parallax (rad^2)
     - ``coord_dec_pm_ra_Cov``: covariance between coord_dec and pm_ra (rad^2/year)
     - ``coord_dec_pm_dec_Cov``: covariance between coord_dec and pm_dec (rad^2/year)
-    - ``coord_dec_parallax_Cov``: covariance between coord_dec and parallax (rad^2/year)
+    - ``coord_dec_parallax_Cov``: covariance between coord_dec and parallax (rad^2)
     - ``pm_ra_parallax_Cov``: covariance between pm_ra and parallax (rad^2/year)
     - ``pm_dec_parallax_Cov``: covariance between pm_dec and parallax (rad^2/year)
diff --git a/python/lsst/meas/algorithms/convertReferenceCatalog.py b/python/lsst/meas/algorithms/convertReferenceCatalog.py
@@ -201,11 +201,16 @@ def _makeSchema(filterNameList, *, addCentroid=False,
             for j in range(i + 1, 5):
                 j_field = fields[j]
                 j_unit = units[j]
+                formatted_unit = "rad^2"
+                if ("year" in i_unit) and ("year" in j_unit):
+                    formatted_unit += "/year^2"
+                elif ("year" in i_unit) or ("year" in j_unit):
+                    formatted_unit += "/year"
                 schema.addField(
                     field=f"{i_field}_{j_field}_Cov",
                     type="F",
                     doc=f"uncertainty covariance between {i_field} and {j_field}",
-                    units=f"{i_unit} {j_unit}"
+                    units=formatted_unit
                 )
     return schema
 

diff --git a/tests/test_convertReferenceCatalog.py b/tests/test_convertReferenceCatalog.py
@@ -167,9 +167,9 @@ def testMakeSchema_fullCovariance(self):
         self.assertIn("pm_ra_parallax_Cov", refSchema)
         self.assertIn("parallaxErr", refSchema)
         self.assertEqual(refSchema['coord_raErr'].asField().getUnits(), "rad")
-        self.assertEqual(refSchema['coord_ra_coord_dec_Cov'].asField().getUnits(), "rad rad")
+        self.assertEqual(refSchema['coord_ra_coord_dec_Cov'].asField().getUnits(), "rad^2")
         self.assertEqual(refSchema['pm_raErr'].asField().getUnits(), "rad/year")
-        self.assertEqual(refSchema['pm_dec_parallax_Cov'].asField().getUnits(), "rad/year rad")
+        self.assertEqual(refSchema['pm_dec_parallax_Cov'].asField().getUnits(), "rad^2/year")
 
     def testCheckFluxUnits(self):
         """Test that we can identify old style fluxes in a schema."""