Remove adding noise on fake objects

Images processed using the LSST software stack are expected to be background noise dominated for faint objects. As such their is no reason to add additional noise to fake objects inserted. This also takes care of a problem where the noise being inserted was artificially too large due to a bug where the gain was not taken into account
lsst-dm · Nov 17, 2017 · 7215e68 · 7215e68
1 parent d74812f
commit 7215e68
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Showing 4 changed files with 6 additions and 8 deletions.
diff --git a/python/lsst/synpipe/positionGalSimFakes.py b/python/lsst/synpipe/positionGalSimFakes.py
@@ -241,9 +241,7 @@ def run(self, exposure, background):
                                             PARENT)
                 galBBox = newBBox
 
-            # Add Noise: Optional?
-            galMaskedImage = fsl.addNoise(galImage, exposure.getDetector(),
-                                          rand_gen=self.npRand)
+            galMaskedImage = lsst.afw.image.MaskedImageF(galImage)
 
             # Put information of the added fake galaxies into the header
             md.set("FAKE%s" % str(galident), "%.3f, %.3f" % (galXY.getX(),

diff --git a/python/lsst/synpipe/positionStarFakes.py b/python/lsst/synpipe/positionStarFakes.py
@@ -90,9 +90,7 @@ def run(self, exposure, background):
                 starImage = starImage.Factory(starImage, newBBox, PARENT)
                 starBBox = newBBox
 
-            starMaskedImage = fsl.addNoise(starImage.convertF(),
-                                           exposure.getDetector(),
-                                           rand_gen=self.npRand)
+            starMaskedImage = afwImage.MaskedImageF(starImage)
 
             starMaskedImage.getMask().set(self.bitmask)
 

diff --git a/python/lsst/synpipe/randomGalSimFakes.py b/python/lsst/synpipe/randomGalSimFakes.py
@@ -100,7 +100,8 @@ def run(self, exposure, background):
                 galImage = galImage.Factory(galImage, newBBox, lsst.afw.image.PARENT)
                 galBBox = newBBox
 
-            galMaskedImage = fsl.addNoise(galImage, exposure.getDetector(), rand_gen=self.npRand)
+            galMaskedImage = lsst.afw.image.MaskedImageF(galImage)
+
             mask = galMaskedImage.getMask()
             mask.set(self.bitmask)
 

diff --git a/python/lsst/synpipe/randomStarFakes.py b/python/lsst/synpipe/randomStarFakes.py
@@ -51,7 +51,8 @@ def run(self, exposure, background):
             self.log.info("Adding fake at: %.1f,%.1f" % (x, y))
             psfImage = psf.computeImage(lsst.afw.geom.Point2D(x, y))
             psfImage *= flux
-            psfMaskedImage = fsl.addNoise(psfImage.convertF(), exposure.getDetector(), rand_gen=self.npRand)
+
+            psfMaskedImage = lsst.afw.image.MaskedImageF(psfImage.convertF())
 
             mask = psfMaskedImage.getMask()
             mask.set(self.bitmask)