lsst.meas.base  14.0-9-g876143c+6
forcedPhotCoadd.py
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1 #!/usr/bin/env python
2 #
3 # LSST Data Management System
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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 
55  def validate(self):
56  ForcedPhotImageTask.ConfigClass.validate(self)
57  if (self.measurement.doReplaceWithNoise and self.footprintDatasetName is not None
58  and self.references.removePatchOverlaps):
59  raise ValueError("Cannot use removePatchOverlaps=True with deblended footprints, as parent "
60  "sources may be rejected while their children are not.")
61 
62 
68 
69 
71  """!
72  A command-line driver for performing forced measurement on coadd images
73 
74  This task is a subclass of ForcedPhotImageTask which is specifically for doing forced
75  measurement on a coadd, using as a reference catalog detections which were made on overlapping
76  coadds (i.e. in other bands).
77 
78  The run method (inherited from ForcedPhotImageTask) takes a lsst.daf.persistence.ButlerDataRef
79  argument that corresponds to a coadd image. This is used to provide all the inputs and outputs
80  for the task:
81  - A "*Coadd_src" (e.g. "deepCoadd_src") dataset is used as the reference catalog. This not loaded
82  directly from the passed dataRef, however; only the patch and tract are used, while the filter
83  is set by the configuration for the references subtask (see CoaddSrcReferencesTask).
84  - A "*Coadd_calexp" (e.g. "deepCoadd_calexp") dataset is used as the measurement image. Note that
85  this means that ProcessCoaddTask must be run on an image before ForcedPhotCoaddTask, in order
86  to generate the "*Coadd_calexp" dataset.
87  - A "*Coadd_forced_src" (e.g. "deepCoadd_forced_src") dataset will be written with the output
88  measurement catalog.
89 
90  In addition to the run method, ForcedPhotCcdTask overrides several methods of ForcedPhotImageTask
91  to specialize it for coadd processing, including makeIdFactory() and fetchReferences(). None of these
92  should be called directly by the user, though it may be useful to override them further in subclasses.
93  """
94 
95  ConfigClass = ForcedPhotCoaddConfig
96  RunnerClass = lsst.pipe.base.ButlerInitializedTaskRunner
97  _DefaultName = "forcedPhotCoadd"
98  dataPrefix = "deepCoadd_"
99 
100  def getExposure(self, dataRef):
101  name = self.config.coaddName + "Coadd_calexp"
102  return dataRef.get(name) if dataRef.datasetExists(name) else None
103 
104  def makeIdFactory(self, dataRef):
105  """Create an object that generates globally unique source IDs from per-CCD IDs and the CCD ID.
106 
107  @param dataRef Data reference from butler. The "CoaddId_bits" and "CoaddId"
108  datasets are accessed. The data ID must have tract and patch keys.
109  """
110  # With the default configuration, this IdFactory doesn't do anything, because
111  # the IDs it generates are immediately overwritten by the ID from the reference
112  # catalog (since that's in config.measurement.copyColumns). But we create one here anyway, to
113  # allow us to revert back to the old behavior of generating new forced source IDs,
114  # just by renaming the ID in config.copyColumns to "object_id".
115  expBits = dataRef.get(self.config.coaddName + "CoaddId_bits")
116  expId = int(dataRef.get(self.config.coaddName + "CoaddId"))
117  return lsst.afw.table.IdFactory.makeSource(expId, 64 - expBits)
118 
119  def getExposureId(self, dataRef):
120  return int(dataRef.get(self.config.coaddName + "CoaddId"))
121 
122  def fetchReferences(self, dataRef, exposure):
123  """Return an iterable of reference sources which overlap the exposure
124 
125  @param dataRef Data reference from butler corresponding to the image to be measured;
126  should have tract, patch, and filter keys.
127  @param exposure lsst.afw.image.Exposure to be measured (not used by this implementation)
128 
129  All work is delegated to the references subtask; see CoaddSrcReferencesTask for information
130  about the default behavior.
131  """
132  skyMap = dataRef.get(self.dataPrefix + "skyMap", immediate=True)
133  tractInfo = skyMap[dataRef.dataId["tract"]]
134  patch = tuple(int(v) for v in dataRef.dataId["patch"].split(","))
135  patchInfo = tractInfo.getPatchInfo(patch)
136  references = lsst.afw.table.SourceCatalog(self.references.schema)
137  references.extend(self.references.fetchInPatches(dataRef, patchList=[patchInfo]))
138  return references
139 
140  def attachFootprints(self, sources, refCat, exposure, refWcs, dataRef):
141  """For coadd forced photometry, we use the deblended HeavyFootprints from the single-band
142  measurements of the same band - because we've guaranteed that the peaks (and hence child sources)
143  will be consistent across all bands before we get to measurement, this should yield reasonable
144  deblending for most sources. It's most likely limitation is that it will not provide good flux
145  upper limits for sources that were not detected in this band but were blended with sources that
146  were.
147  """
148  if self.config.footprintDatasetName is None:
149  return ForcedPhotImageTask.attachFootprints(self, sources, refCat, exposure, refWcs, dataRef)
150  self.log.info("Loading deblended footprints for sources from %s, %s" %
151  (self.config.footprintDatasetName, dataRef.dataId))
152  fpCat = dataRef.get("%sCoadd_%s" % (self.config.coaddName, self.config.footprintDatasetName),
153  immediate=True)
154  for refRecord, srcRecord in zip(refCat, sources):
155  fpRecord = fpCat.find(refRecord.getId())
156  if fpRecord is None:
157  raise LookupError("Cannot find Footprint for source %s; please check that %sCoadd_%s "
158  "IDs are compatible with reference source IDs" %
159  (srcRecord.getId(), self.config.coaddName,
160  self.config.footprintDatasetName))
161  srcRecord.setFootprint(fpRecord.getFootprint())
162 
163  @classmethod
164  def _makeArgumentParser(cls):
165  parser = lsst.pipe.base.ArgumentParser(name=cls._DefaultName)
166  parser.add_id_argument("--id", "deepCoadd_forced_src", help="data ID, with raw CCD keys + tract",
167  ContainerClass=lsst.coadd.utils.CoaddDataIdContainer)
168  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.