Propagate coordinate covariance in catalogs

python/lsst/pipe/tasks/calibrate.py

@@ -417,6 +417,7 @@ def __init__(self, astromRefObjLoader=None,
         else:
             self.schemaMapper = None
             self.schema = afwTable.SourceTable.makeMinimalSchema()
+        afwTable.CoordKey.addErrorFields(self.schema)
         self.makeSubtask('detection', schema=self.schema)
 
         self.algMetadata = dafBase.PropertyList()

python/lsst/pipe/tasks/calibrateImage.py

@@ -352,6 +352,7 @@ def __init__(self, initial_stars_schema=None, **kwargs):
         # star measurement subtasks
         if initial_stars_schema is None:
             initial_stars_schema = afwTable.SourceTable.makeMinimalSchema()
+        afwTable.CoordKey.addErrorFields(initial_stars_schema)
         self.makeSubtask("star_detection", schema=initial_stars_schema)
         self.makeSubtask("star_deblend", schema=initial_stars_schema)
         self.makeSubtask("star_measurement", schema=initial_stars_schema)

python/lsst/pipe/tasks/functors.py

@@ -708,6 +708,40 @@ def __call__(self, catalog, **kwargs):
         return super().__call__(catalog, **kwargs)
 
 
+class RAErrColumn(CoordColumn):
+    """Uncertainty in Right Ascension, in degrees."""
+    name = 'RAErr'
+    _defaultNoDup = True
+
+    def __init__(self, **kwargs):
+        super().__init__('coord_raErr', **kwargs)
+
+
+class DecErrColumn(CoordColumn):
+    """Uncertainty in declination, in degrees."""
+    name = 'DecErr'
+    _defaultNoDup = True
+
+    def __init__(self, **kwargs):
+        super().__init__('coord_decErr', **kwargs)
+
+
+class RADecCovColumn(Column):
+    """Coordinate covariance column, in degrees."""
+    _radians = True
+    name = 'RADecCov'
+    _defaultNoDup = True
+
+    def __init__(self, **kwargs):
+        super().__init__('coord_ra_dec_Cov', **kwargs)
+
+    def _func(self, df):
+        # Must not modify original column in case that column is used by
+        # another functor.
+        output = df[self.col]*(180/np.pi)**2 if self._radians else df[self.col]
+        return output
+
+
 class HtmIndex20(Functor):
     """Compute the level 20 HtmIndex for the catalog.
 

python/lsst/pipe/tasks/multiBand.py

@@ -508,6 +508,7 @@ def __init__(self, schema=None, peakSchema=None, refObjLoader=None, initInputs=N
         self.schemaMapper = afwTable.SchemaMapper(schema)
         self.schemaMapper.addMinimalSchema(schema)
         self.schema = self.schemaMapper.getOutputSchema()
+        afwTable.CoordKey.addErrorFields(self.schema)
         self.algMetadata = PropertyList()
         self.makeSubtask("measurement", schema=self.schema, algMetadata=self.algMetadata)
         self.makeSubtask("setPrimaryFlags", schema=self.schema)

schemas/Object.yaml

@@ -18,6 +18,18 @@ funcs:
         # coord_dec because "dec" is reserved in most SQL DBs
         functor: DecColumn
         dataset: ref
+    coord_raErr:
+        # error in reference position for merged "ref" cat.
+        functor: RAErrColumn
+        dataset: ref
+    coord_decErr:
+        # error in reference position for merged "ref" cat.
+        functor: DecErrColumn
+        dataset: ref
+    coord_ra_dec_Cov:
+        # covariance in reference position for merged "ref" cat.
+        functor: RADecCovColumn
+        dataset: ref
     ra:
         functor: CoordColumn
         args: coord_ra
@@ -34,8 +46,18 @@ funcs:
         args: coord_dec
         dataset: meas
 
-    # raErr:  not available yet DM-15180
-    # decErr: not available yet DM-15180
+    raErr:
+        functor: RAErrColumn
+        dataset: meas
+        noDup: False
+    decErr:
+        functor: DecErrColumn
+        dataset: meas
+        noDup: False
+    ra_dec_Cov:
+        functor: RADecCovColumn
+        dataset: meas
+        noDup: False
     # Reference band is same for all measurements
     refBand:
         functor: ReferenceBand

schemas/Source.yaml

@@ -37,17 +37,20 @@ funcs:
     # x_y_Cov: not available
     ra:
         functor: RAColumn
-    # raErr: not available yet DM-15180
     dec:
         functor: DecColumn
 
    # RFC-924: Temporarily keep a duplicate "decl" entry for backwards
    # compatibility. To be removed after September 2023.
     decl:
         functor: DecColumn
-
-    # decErr: not available yet DM-15180
-    # ra_dec_Cov: not available yet
+
+    raErr:
+        functor: RAErrColumn
+    decErr:
+        functor: DecErrColumn
+    ra_dec_Cov:
+        functor: RADecCovColumn    
     # One calibrated Calib flux is important:
     calibFlux:
         functor: LocalNanojansky

tests/test_calibrateImage.py

@@ -75,10 +75,8 @@ def setUp(self):
         dataset.addSource(instFlux=500*noise*psf_scale, centroid=center, shape=shape)
 
         schema = dataset.makeMinimalSchema()
-        schema.addField("truth_flux", type=np.float64, doc="true flux", units="nJy")
-        schema.addField("truth_fluxErr", type=np.float64, doc="true fluxErr", units="nJy")
-
-        self.truth_exposure, self.truth_cat = dataset.realize(noise=noise, schema=dataset.makeMinimalSchema())
+        afwTable.CoordKey.addErrorFields(schema)
+        self.truth_exposure, self.truth_cat = dataset.realize(noise=noise, schema=schema)
         lsst.afw.table.updateSourceCoords(self.truth_exposure.wcs, self.truth_cat)
         # To make it look like a version=1 (nJy fluxes) refcat
         self.truth_cat = self.truth_exposure.photoCalib.calibrateCatalog(self.truth_cat)