Merge pull request #167 from lsst/tickets/DM-28233

DM-28233: Fix refcat position error units
lsst · Jan 7, 2021 · cff38f6 · cff38f6
2 parents 642e80a + f3ea031
commit cff38f6
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Showing 4 changed files with 30 additions and 26 deletions.
diff --git a/src/Associations.cc b/src/Associations.cc
@@ -247,10 +247,11 @@ void Associations::collectRefStars(afw::table::SimpleCatalog &refCat, geom::Angl
         auto star = std::make_shared<RefStar>(ra, dec, flux, fluxErr);
 
         if (std::isnan(refCoordinateErr)) {
-            star->vx = record->get(raErrKey);
-            star->vy = record->get(decErrKey);
+            // refcat errors are unitless but stored as radians: convert to deg**2
+            star->vx = std::pow(lsst::geom::radToDeg(record->get(raErrKey)), 2);
+            star->vy = std::pow(lsst::geom::radToDeg(record->get(decErrKey)), 2);
         } else {
-            // Compute and use the fake errors
+            // Convert the fake errors from mas to deg**2
             star->vx = std::pow(refCoordinateErr / 1000. / 3600. / std::cos(coord.getLatitude()), 2);
             star->vy = std::pow(refCoordinateErr / 1000. / 3600., 2);
         }

diff --git a/tests/test_jointcal_cfht.py b/tests/test_jointcal_cfht.py
@@ -87,7 +87,7 @@ def test_jointcalTask_2_visits(self):
             self.config.debugOutputPath = tempdir
 
             # See Readme for an explanation of these empirical values.
-            dist_rms_relative = 14e-3*u.arcsecond
+            dist_rms_relative = 16e-3*u.arcsecond
             pa1 = 0.049
             metrics = {'collected_astrometry_refStars': 867,
                        'collected_photometry_refStars': 11570,
@@ -99,8 +99,8 @@ def test_jointcalTask_2_visits(self):
                        'selected_photometry_fittedStars': 2232,
                        'selected_astrometry_ccdImages': 12,
                        'selected_photometry_ccdImages': 12,
-                       'astrometry_final_chi2': 1146.81,
-                       'astrometry_final_ndof': 2486,
+                       'astrometry_final_chi2': 1159.736,
+                       'astrometry_final_ndof': 1872,
                        'photometry_final_chi2': 11624.3,
                        'photometry_final_ndof': 2778
                        }
@@ -131,14 +131,14 @@ def setup_jointcalTask_2_visits_constrainedAstrometry(self):
         self.jointcalStatistics.do_photometry = False
 
         # See Readme for an explanation of these empirical values.
-        dist_rms_relative = 12e-3*u.arcsecond
+        dist_rms_relative = 16e-3*u.arcsecond
         metrics = {'collected_astrometry_refStars': 867,
                    'selected_astrometry_refStars': 332,
                    'associated_astrometry_fittedStars': 2272,
                    'selected_astrometry_fittedStars': 1229,
                    'selected_astrometry_ccdImages': 12,
-                   'astrometry_final_chi2': 1204.72,
-                   'astrometry_final_ndof': 2576,
+                   'astrometry_final_chi2': 1124.0575,
+                   'astrometry_final_ndof': 1912,
                    }
 
         return dist_rms_relative, metrics
@@ -158,6 +158,9 @@ def test_jointcalTask_2_visits_constrainedAstrometry_no_rank_update(self):
         """Demonstrate that skipping the rank update doesn't substantially affect astrometry.
         """
         relative_error, metrics = self.setup_jointcalTask_2_visits_constrainedAstrometry()
+        metrics['astrometry_final_chi2'] = 1069.348
+        metrics['astrometry_final_ndof'] = 1900
+
         self.config.astrometryDoRankUpdate = False
 
         self._testJointcalTask(2, relative_error, self.dist_rms_absolute, None, metrics=metrics)
@@ -168,8 +171,8 @@ def test_jointcalTask_2_visits_constrainedAstrometry_4sigma_outliers(self):
         """
         dist_rms_relative, metrics = self.setup_jointcalTask_2_visits_constrainedAstrometry()
         self.config.outlierRejectSigma = 4
-        metrics['astrometry_final_chi2'] = 849.75
-        metrics['astrometry_final_ndof'] = 2390
+        metrics['astrometry_final_chi2'] = 757.027
+        metrics['astrometry_final_ndof'] = 1732
 
         self._testJointcalTask(2, dist_rms_relative, self.dist_rms_absolute, None, metrics=metrics)
 

diff --git a/tests/test_jointcal_decam.py b/tests/test_jointcal_decam.py
@@ -96,8 +96,8 @@ def test_jointcalTask_2_visits(self):
                    'selected_photometry_fittedStars': 4637,
                    'selected_astrometry_ccdImages': 15,
                    'selected_photometry_ccdImages': 15,
-                   'astrometry_final_chi2': 1.21494,
-                   'astrometry_final_ndof': 560,
+                   'astrometry_final_chi2': 2803.108,
+                   'astrometry_final_ndof': 890,
                    'photometry_final_chi2': 16529,
                    'photometry_final_ndof': 3634,
                    }

diff --git a/tests/test_jointcal_hsc.py b/tests/test_jointcal_hsc.py
@@ -89,8 +89,8 @@ def test_jointcalTask_2_visits_simple(self):
                    'selected_photometry_fittedStars': 1731,
                    'selected_astrometry_ccdImages': 6,
                    'selected_photometry_ccdImages': 6,
-                   'astrometry_final_chi2': 683.783,
-                   'astrometry_final_ndof': 1916,
+                   'astrometry_final_chi2': 835.473,
+                   'astrometry_final_ndof': 1918,
                    'photometry_final_chi2': 4997.62,
                    'photometry_final_ndof': 2188
                    }
@@ -127,8 +127,8 @@ def test_jointcalTask_10_visits_simple_astrometry_no_photometry(self):
                    'associated_astrometry_fittedStars': 5860,
                    'selected_astrometry_fittedStars': 3568,
                    'selected_astrometry_ccdImages': 30,
-                   'astrometry_final_chi2': 9621.29,
-                   'astrometry_final_ndof': 18562,
+                   'astrometry_final_chi2': 10218.518,
+                   'astrometry_final_ndof': 18574,
                    }
         self._testJointcalTask(10, dist_rms_relative, dist_rms_absolute, pa1, metrics=metrics)
 
@@ -199,8 +199,8 @@ def test_JointcalTask_2_visits_simple_astrometry_no_photometry(self):
                    'associated_astrometry_fittedStars': 2070,
                    'selected_astrometry_fittedStars': 989,
                    'selected_astrometry_ccdImages': 6,
-                   'astrometry_final_chi2': 683.783,
-                   'astrometry_final_ndof': 1916,
+                   'astrometry_final_chi2': 835.473,
+                   'astrometry_final_ndof': 1918,
                    }
         self.config = lsst.jointcal.jointcal.JointcalConfig()
         self.config.astrometryModel = "simple"
@@ -232,8 +232,8 @@ def test_jointcalTask_2_visits_simple_astrometry_no_photometry_match_cut_10(self
                    'associated_astrometry_fittedStars': 2070,
                    'selected_astrometry_fittedStars': 1042,
                    'selected_astrometry_ccdImages': 6,
-                   'astrometry_final_chi2': 683.369,
-                   'astrometry_final_ndof': 1910,
+                   'astrometry_final_chi2': 800.346,
+                   'astrometry_final_ndof': 1864,
                    }
         pa1 = None
         self._testJointcalTask(2, self.dist_rms_relative, dist_rms_absolute, pa1, metrics=metrics)
@@ -247,15 +247,15 @@ def test_jointcalTask_3_visits_simple_astrometry_no_photometry(self):
         self.jointcalStatistics.do_photometry = False
 
         # More visits and slightly worse relative and absolute rms.
-        dist_rms_relative = 8.2e-3*u.arcsecond
+        dist_rms_relative = 8.3e-3*u.arcsecond
         dist_rms_absolute = 24e-3*u.arcsecond
         metrics = {'collected_astrometry_refStars': 1038,
                    'selected_astrometry_refStars': 209,
                    'associated_astrometry_fittedStars': 3199,
                    'selected_astrometry_fittedStars': 1282,
                    'selected_astrometry_ccdImages': 9,
-                   'astrometry_final_chi2': 1013.20,
-                   'astrometry_final_ndof': 2900,
+                   'astrometry_final_chi2': 1221.63,
+                   'astrometry_final_ndof': 2892,
                    }
         pa1 = None
         self._testJointcalTask(3, dist_rms_relative, dist_rms_absolute, pa1, metrics=metrics)
@@ -278,8 +278,8 @@ def test_jointcalTask_3_visits_simple_astrometry_no_photometry_min_measurements_
                    'associated_astrometry_fittedStars': 3199,
                    'selected_astrometry_fittedStars': 432,
                    'selected_astrometry_ccdImages': 9,
-                   'astrometry_final_chi2': 360.884,
-                   'astrometry_final_ndof': 1294,
+                   'astrometry_final_chi2': 567.443,
+                   'astrometry_final_ndof': 1286,
                    }
         pa1 = None
         self._testJointcalTask(3, dist_rms_relative, dist_rms_absolute, pa1, metrics=metrics)