Merge pull request #983 from lsst/tickets/DM-42979

DM-42979: Use calibFlux for source selector

python/lsst/pipe/tasks/calibrateImage.py

@@ -391,6 +391,9 @@ def setDefaults(self):
         # Keep sky sources in the output catalog, even though they aren't
         # wanted for calibration.
         self.star_selector["science"].doSkySources = True
+        # Set the flux and error fields
+        self.star_selector["science"].signalToNoise.fluxField = "slot_CalibFlux_instFlux"
+        self.star_selector["science"].signalToNoise.errField = "slot_CalibFlux_instFluxErr"
 
         # Use the affine WCS fitter (assumes we have a good camera geometry).
         self.astrometry.wcsFitter.retarget(lsst.meas.astrom.FitAffineWcsTask)
@@ -986,6 +989,9 @@ def _fit_photometry(self, exposure, stars):
             unchanged.
         stars : `lsst.afw.table.SourceCatalog`
             Good stars selected for use in calibration.
+        background : `lsst.afw.math.BackgroundList`
+            Background that was fit to the exposure during detection of the
+            above stars.
 
         Returns
         -------

python/lsst/pipe/tasks/photoCal.py

@@ -103,6 +103,12 @@ def validate(self):
             raise RuntimeError("applyColorTerms=True requires photoCatName is non-None")
         if self.applyColorTerms and len(self.colorterms.data) == 0:
             raise RuntimeError("applyColorTerms=True requires colorterms be provided")
+        if self.fluxField != self.match.sourceSelection.signalToNoise.fluxField:
+            raise RuntimeError("Configured flux field %s does not match source selector field %s",
+                               self.fluxField, self.match.sourceSelection.signalToNoise.fluxField)
+        if self.fluxField + "Err" != self.match.sourceSelection.signalToNoise.errField:
+            raise RuntimeError("Configured flux field %sErr does not match source selector error field %s",
+                               self.fluxField, self.match.sourceSelection.signalToNoise.errField)
 
     def setDefaults(self):
         pexConf.Config.setDefaults(self)
@@ -114,6 +120,10 @@ def setDefaults(self):
             "base_PixelFlags_flag_saturated",
         ]
         self.match.sourceSelection.doUnresolved = True
+        self.match.sourceSelection.doSignalToNoise = True
+        self.match.sourceSelection.signalToNoise.minimum = 10.0
+        self.match.sourceSelection.signalToNoise.fluxField = self.fluxField
+        self.match.sourceSelection.signalToNoise.errField = self.fluxField + "Err"
 
 
 class PhotoCalTask(pipeBase.Task):
@@ -322,12 +332,8 @@ def run(self, exposure, sourceCat, expId=0):
         ----------
         exposure : `lsst.afw.image.Exposure`
             Exposure upon which the sources in the matches were detected.
-        sourceCat : `lsst.afw.image.SourceCatalog`
-            A catalog of sources to use in the calibration
-            (i.e. a `list` of `lsst.afw.table.Match` with
-            first being of type `lsst.afw.table.SimpleRecord` and second type `lsst.afw.table.SourceRecord`
-            the reference object and matched object respectively).
-            Will not be modified except to set the outputField if requested.
+        sourceCat : `lsst.afw.table.SourceCatalog`
+            Good stars selected for use in calibration.
         expId : `int`, optional
             Exposure ID.
 

tests/test_calibrateImage.py

@@ -189,7 +189,7 @@ def _check_run(self, calibrate, result, expect_calibrated_pixels: bool = True):
         self.assertEqual(result.stars["slot_PsfFlux_mag"].unit, u.ABmag)
 
         # Should have detected all S/N >= 10 sources plus 2 sky sources, whether 1 or 2 snaps.
-        self.assertEqual(len(result.stars), 7)
+        self.assertEqual(len(result.stars), 6)
         # Did the psf flags get propagated from the psf_stars catalog?
         self.assertEqual(result.stars["calib_psf_used"].sum(), 3)
 
@@ -319,7 +319,7 @@ def test_find_stars(self):
 
         # Only 5 psf-like sources with S/N>10 should be in the output catalog,
         # plus two sky sources.
-        self.assertEqual(len(stars), 7)
+        self.assertEqual(len(stars), 6)
         self.assertTrue(stars.isContiguous())
         # Sort in order of brightness, to easily compare with expected positions.
         stars.sort(stars.getPsfFluxSlot().getMeasKey())
@@ -420,8 +420,8 @@ def test_match_psf_stars(self):
         # sort() above leaves the catalog non-contiguous.
         stars = stars.copy(deep=True)
         np.testing.assert_array_equal(stars["calib_psf_candidate"],
-                                      [False, False, False, False, True, True, True])
-        np.testing.assert_array_equal(stars["calib_psf_used"], [False, False, False, False, True, True, True])
+                                      [False, False, False, True, True, True])
+        np.testing.assert_array_equal(stars["calib_psf_used"], [False, False, False, True, True, True])
         # Too few sources to reserve any in these tests.
         self.assertEqual(stars["calib_psf_reserved"].sum(), 0)
 

tests/test_photoCal.py

@@ -100,6 +100,8 @@ def setUp(self):
         # The test and associated data have been prepared on the basis that we
         # use the PsfFlux to perform photometry.
         self.config.fluxField = "base_PsfFlux_instFlux"
+        self.config.match.sourceSelection.signalToNoise.fluxField = "base_PsfFlux_instFlux"
+        self.config.match.sourceSelection.signalToNoise.errField = "base_PsfFlux_instFluxErr"
 
     def tearDown(self):
         del self.srcCat