Use SNR starSelector for measurePsf; add assembleCoadd.py with WCSSel…

…ectImages

config/latiss/assembleCoadd.py

@@ -0,0 +1,24 @@
+# This file is part of obs_lsst.
+#
+# Developed for the LSST Data Management System.
+# This product includes software developed by the LSST Project
+# (http://www.lsst.org).
+# See the COPYRIGHT file at the top-level directory of this distribution
+# for details of code ownership.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the LSST License Statement and
+# the GNU General Public License along with this program.  If not,
+# see <http://www.lsstcorp.org/LegalNotices/>.
+
+from lsst.pipe.tasks.selectImages import WcsSelectImagesTask
+config.select.retarget(WcsSelectImagesTask)

config/latiss/characterizeImage.py

@@ -1,10 +1,29 @@
-# Switch to PCA determiner as it is much more robust when there are very few
-# sources. Increase default FWHM due to plate scale and reduce fluxMin due to
-# short expTimes on a 1.2m telescope. nEigenComponents and spatialOrder set to
-# min values so that we always succeed even with one or two stars.
-config.measurePsf.psfDeterminer = 'pca'
-config.measurePsf.psfDeterminer['pca'].spatialOrder = 0
-config.measurePsf.psfDeterminer['pca'].nEigenComponents = 1
-config.measurePsf.starSelector['objectSize'].fluxMin = 2500
+# To ensure as many candidates as possible are passed to measurePsf, we use a simple 'science' star selector, 
+# including only a signal to noise limit and pixel flag filter to filter out bad candidates. THe SNR>30 limit
+# corresponds to a band-dependent magnitude of around 19 on LATISS in a 30s image, so galaxy contamination is 
+# limited. The default objectSize star selector is not appropriate given the low number of sources and 
+# PSF variations across the FOV. 
+config.measurePsf.starSelector = 'science'
+config.measurePsf.starSelector['science'].doSignalToNoise = True
+config.measurePsf.starSelector['science'].signalToNoise.minimum = 30.0
+config.measurePsf.starSelector['science'].signalToNoise.maximum = None
+config.measurePsf.starSelector['science'].signalToNoise.fluxField = "base_GaussianFlux_instFlux"
+config.measurePsf.starSelector['science'].signalToNoise.errField = "base_GaussianFlux_instFluxErr"
+config.measurePsf.starSelector['science'].doFlags = True
+config.measurePsf.starSelector['science'].flags.bad = ["base_PixelFlags_flag_edge",
+                        "base_PixelFlags_flag_interpolatedCenter",
+                        "base_PixelFlags_flag_saturatedCenter",
+                        "base_PixelFlags_flag_crCenter",
+                        "base_PixelFlags_flag_bad",
+                        "base_PixelFlags_flag_interpolated"]
+
+# Use these to run the pca psf estimator 
+#config.measurePsf.psfDeterminer = 'pca'
+#config.measurePsf.psfDeterminer['pca'].spatialOrder = 0
+
+# Set PSF spatialOrder to 0 to calculate the mean PSF profile across the detector, i.e. no 
+# spatial variations. 
+config.measurePsf.psfDeterminer['piff'].spatialOrder = 0
+
 config.installSimplePsf.width = 81  
 config.installSimplePsf.fwhm = 2.355*2 # LATISS platescale is 2x LSST nominal