lsst.meas.base  14.0-12-g233aa8e+4
forcedPhotCoadd.py
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1 #!/usr/bin/env python
2 #
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23 from builtins import zip
24 
25 import lsst.pex.config
26 import lsst.pipe.base
27 import lsst.coadd.utils
28 import lsst.afw.table
29 
30 from .forcedPhotImage import ForcedPhotImageConfig, ForcedPhotImageTask
31 
32 __all__ = ("ForcedPhotCoaddConfig", "ForcedPhotCoaddTask")
33 
34 
36  footprintDatasetName = lsst.pex.config.Field(
37  doc="Dataset (without coadd prefix) that should be used to obtain (Heavy)Footprints for sources. "
38  "Must have IDs that match those of the reference catalog."
39  "If None, Footprints will be generated by transforming the reference Footprints.",
40  dtype=str,
41  default="meas",
42  optional=True
43  )
44 
45  def setDefaults(self):
46  ForcedPhotImageTask.ConfigClass.setDefaults(self)
47  # Copy 'id' and 'parent' columns without renaming them; since these are
48  # the only IDs we have in coadd processing, there's no need to qualify
49  # them with 'object'.
50  self.measurement.copyColumns["id"] = "id"
51  self.measurement.copyColumns["parent"] = "parent"
52  self.references.removePatchOverlaps = False # see validate() for why
53  self.measurement.plugins.names |= ['base_InputCount', 'base_Variance']
54  self.measurement.plugins['base_PixelFlags'].masksFpAnywhere = ['CLIPPED', 'SENSOR_EDGE',
55  'INEXACT_PSF']
56 
57  def validate(self):
58  ForcedPhotImageTask.ConfigClass.validate(self)
59  if (self.measurement.doReplaceWithNoise and self.footprintDatasetName is not None
60  and self.references.removePatchOverlaps):
61  raise ValueError("Cannot use removePatchOverlaps=True with deblended footprints, as parent "
62  "sources may be rejected while their children are not.")
63 
64 
70 
71 
73  """!
74  A command-line driver for performing forced measurement on coadd images
75 
76  This task is a subclass of ForcedPhotImageTask which is specifically for doing forced
77  measurement on a coadd, using as a reference catalog detections which were made on overlapping
78  coadds (i.e. in other bands).
79 
80  The run method (inherited from ForcedPhotImageTask) takes a lsst.daf.persistence.ButlerDataRef
81  argument that corresponds to a coadd image. This is used to provide all the inputs and outputs
82  for the task:
83  - A "*Coadd_src" (e.g. "deepCoadd_src") dataset is used as the reference catalog. This not loaded
84  directly from the passed dataRef, however; only the patch and tract are used, while the filter
85  is set by the configuration for the references subtask (see CoaddSrcReferencesTask).
86  - A "*Coadd_calexp" (e.g. "deepCoadd_calexp") dataset is used as the measurement image. Note that
87  this means that ProcessCoaddTask must be run on an image before ForcedPhotCoaddTask, in order
88  to generate the "*Coadd_calexp" dataset.
89  - A "*Coadd_forced_src" (e.g. "deepCoadd_forced_src") dataset will be written with the output
90  measurement catalog.
91 
92  In addition to the run method, ForcedPhotCcdTask overrides several methods of ForcedPhotImageTask
93  to specialize it for coadd processing, including makeIdFactory() and fetchReferences(). None of these
94  should be called directly by the user, though it may be useful to override them further in subclasses.
95  """
96 
97  ConfigClass = ForcedPhotCoaddConfig
98  RunnerClass = lsst.pipe.base.ButlerInitializedTaskRunner
99  _DefaultName = "forcedPhotCoadd"
100  dataPrefix = "deepCoadd_"
101 
102  def getExposure(self, dataRef):
103  name = self.config.coaddName + "Coadd_calexp"
104  return dataRef.get(name) if dataRef.datasetExists(name) else None
105 
106  def makeIdFactory(self, dataRef):
107  """Create an object that generates globally unique source IDs from per-CCD IDs and the CCD ID.
108 
109  @param dataRef Data reference from butler. The "CoaddId_bits" and "CoaddId"
110  datasets are accessed. The data ID must have tract and patch keys.
111  """
112  # With the default configuration, this IdFactory doesn't do anything, because
113  # the IDs it generates are immediately overwritten by the ID from the reference
114  # catalog (since that's in config.measurement.copyColumns). But we create one here anyway, to
115  # allow us to revert back to the old behavior of generating new forced source IDs,
116  # just by renaming the ID in config.copyColumns to "object_id".
117  expBits = dataRef.get(self.config.coaddName + "CoaddId_bits")
118  expId = int(dataRef.get(self.config.coaddName + "CoaddId"))
119  return lsst.afw.table.IdFactory.makeSource(expId, 64 - expBits)
120 
121  def getExposureId(self, dataRef):
122  return int(dataRef.get(self.config.coaddName + "CoaddId"))
123 
124  def fetchReferences(self, dataRef, exposure):
125  """Return an iterable of reference sources which overlap the exposure
126 
127  @param dataRef Data reference from butler corresponding to the image to be measured;
128  should have tract, patch, and filter keys.
129  @param exposure lsst.afw.image.Exposure to be measured (not used by this implementation)
130 
131  All work is delegated to the references subtask; see CoaddSrcReferencesTask for information
132  about the default behavior.
133  """
134  skyMap = dataRef.get(self.dataPrefix + "skyMap", immediate=True)
135  tractInfo = skyMap[dataRef.dataId["tract"]]
136  patch = tuple(int(v) for v in dataRef.dataId["patch"].split(","))
137  patchInfo = tractInfo.getPatchInfo(patch)
138  references = lsst.afw.table.SourceCatalog(self.references.schema)
139  references.extend(self.references.fetchInPatches(dataRef, patchList=[patchInfo]))
140  return references
141 
142  def attachFootprints(self, sources, refCat, exposure, refWcs, dataRef):
143  """For coadd forced photometry, we use the deblended HeavyFootprints from the single-band
144  measurements of the same band - because we've guaranteed that the peaks (and hence child sources)
145  will be consistent across all bands before we get to measurement, this should yield reasonable
146  deblending for most sources. It's most likely limitation is that it will not provide good flux
147  upper limits for sources that were not detected in this band but were blended with sources that
148  were.
149  """
150  if self.config.footprintDatasetName is None:
151  return ForcedPhotImageTask.attachFootprints(self, sources, refCat, exposure, refWcs, dataRef)
152  self.log.info("Loading deblended footprints for sources from %s, %s" %
153  (self.config.footprintDatasetName, dataRef.dataId))
154  fpCat = dataRef.get("%sCoadd_%s" % (self.config.coaddName, self.config.footprintDatasetName),
155  immediate=True)
156  for refRecord, srcRecord in zip(refCat, sources):
157  fpRecord = fpCat.find(refRecord.getId())
158  if fpRecord is None:
159  raise LookupError("Cannot find Footprint for source %s; please check that %sCoadd_%s "
160  "IDs are compatible with reference source IDs" %
161  (srcRecord.getId(), self.config.coaddName,
162  self.config.footprintDatasetName))
163  srcRecord.setFootprint(fpRecord.getFootprint())
164 
165  @classmethod
166  def _makeArgumentParser(cls):
167  parser = lsst.pipe.base.ArgumentParser(name=cls._DefaultName)
168  parser.add_id_argument("--id", "deepCoadd_forced_src", help="data ID, with raw CCD keys + tract",
169  ContainerClass=lsst.coadd.utils.CoaddDataIdContainer)
170  return parser
A base class for command-line forced measurement drivers.
static std::shared_ptr< IdFactory > makeSource(RecordId expId, int reserved)
def attachFootprints(self, sources, refCat, exposure, refWcs, dataRef)
A command-line driver for performing forced measurement on coadd images.
Config class for forced measurement driver task.