Force variance plane to be unchanged in DcrAssembleCoaddTask

lsst · Dec 7, 2018 · d546943 · d546943
1 parent 5a0743d
commit d546943
Showing 1 changed file with 10 additions and 2 deletions.
diff --git a/python/lsst/pipe/tasks/dcrAssembleCoadd.py b/python/lsst/pipe/tasks/dcrAssembleCoadd.py
@@ -350,6 +350,9 @@ def run(self, skyInfo, tempExpRefList, imageScalerList, weightList,
         """
         templateCoadd = supplementaryData.templateCoadd
         baseMask = templateCoadd.mask.clone()
+        # The variance plane is for each subfilter
+        # and should be proportionately lower than the full-band image
+        baseVariance = templateCoadd.variance.clone()/self.config.dcrNumSubfilters
         spanSetMaskList = self.findArtifacts(templateCoadd, tempExpRefList, imageScalerList)
         # Note that the mask gets cleared in ``findArtifacts``, but we want to preserve the mask.
         templateCoadd.setMask(baseMask)
@@ -449,7 +452,8 @@ def run(self, skyInfo, tempExpRefList, imageScalerList, weightList,
         dcrCoadds = self.fillCoadd(dcrModels, skyInfo, tempExpRefList, weightList,
                                    calibration=self.scaleZeroPoint.getCalib(),
                                    coaddInputs=templateCoadd.getInfo().getCoaddInputs(),
-                                   mask=baseMask)
+                                   mask=baseMask,
+                                   variance=baseVariance)
         coaddExposure = self.stackCoadd(dcrCoadds)
         return pipeBase.Struct(coaddExposure=coaddExposure, nImage=nImage,
                                dcrCoadds=dcrCoadds, dcrNImages=dcrNImages)
@@ -762,7 +766,7 @@ def stackCoadd(self, dcrCoadds):
         return coaddExposure
 
     def fillCoadd(self, dcrModels, skyInfo, tempExpRefList, weightList, calibration=None, coaddInputs=None,
-                  mask=None):
+                  mask=None, variance=None):
         """Create a list of coadd exposures from a list of masked images.
 
         Parameters
@@ -781,6 +785,8 @@ def fillCoadd(self, dcrModels, skyInfo, tempExpRefList, weightList, calibration=
             A record of the observations that are included in the coadd.
         mask : `lsst.afw.image.Mask`, optional
             Optional mask to override the values in the final coadd.
+        variance : `lsst.afw.image.Image`, optional
+            Optional variance plane to override the values in the final coadd.
 
         Returns
         -------
@@ -801,6 +807,8 @@ def fillCoadd(self, dcrModels, skyInfo, tempExpRefList, weightList, calibration=
             coaddExposure.setMaskedImage(model[skyInfo.bbox])
             if mask is not None:
                 coaddExposure.setMask(mask)
+            if variance is not None:
+                coaddExposure.setVariance(variance)
             dcrCoadds.append(coaddExposure)
         return dcrCoadds