lsst.meas.base  14.0-17-g4f4ea82
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  self.measurement.plugins['base_PixelFlags'].masksFpAnywhere = ['CLIPPED', 'SENSOR_EDGE',
55  'REJECTED', 'INEXACT_PSF']
56  self.measurement.plugins['base_PixelFlags'].masksFpCenter = ['CLIPPED', 'SENSOR_EDGE',
57  'REJECTED', 'INEXACT_PSF']
58 
59  def validate(self):
60  ForcedPhotImageTask.ConfigClass.validate(self)
61  if (self.measurement.doReplaceWithNoise and self.footprintDatasetName is not None
62  and self.references.removePatchOverlaps):
63  raise ValueError("Cannot use removePatchOverlaps=True with deblended footprints, as parent "
64  "sources may be rejected while their children are not.")
65 
66 
72 
73 
75  """!
76  A command-line driver for performing forced measurement on coadd images
77 
78  This task is a subclass of ForcedPhotImageTask which is specifically for doing forced
79  measurement on a coadd, using as a reference catalog detections which were made on overlapping
80  coadds (i.e. in other bands).
81 
82  The run method (inherited from ForcedPhotImageTask) takes a lsst.daf.persistence.ButlerDataRef
83  argument that corresponds to a coadd image. This is used to provide all the inputs and outputs
84  for the task:
85  - A "*Coadd_src" (e.g. "deepCoadd_src") dataset is used as the reference catalog. This not loaded
86  directly from the passed dataRef, however; only the patch and tract are used, while the filter
87  is set by the configuration for the references subtask (see CoaddSrcReferencesTask).
88  - A "*Coadd_calexp" (e.g. "deepCoadd_calexp") dataset is used as the measurement image. Note that
89  this means that ProcessCoaddTask must be run on an image before ForcedPhotCoaddTask, in order
90  to generate the "*Coadd_calexp" dataset.
91  - A "*Coadd_forced_src" (e.g. "deepCoadd_forced_src") dataset will be written with the output
92  measurement catalog.
93 
94  In addition to the run method, ForcedPhotCcdTask overrides several methods of ForcedPhotImageTask
95  to specialize it for coadd processing, including makeIdFactory() and fetchReferences(). None of these
96  should be called directly by the user, though it may be useful to override them further in subclasses.
97  """
98 
99  ConfigClass = ForcedPhotCoaddConfig
100  RunnerClass = lsst.pipe.base.ButlerInitializedTaskRunner
101  _DefaultName = "forcedPhotCoadd"
102  dataPrefix = "deepCoadd_"
103 
104  def getExposure(self, dataRef):
105  name = self.config.coaddName + "Coadd_calexp"
106  return dataRef.get(name) if dataRef.datasetExists(name) else None
107 
108  def makeIdFactory(self, dataRef):
109  """Create an object that generates globally unique source IDs from per-CCD IDs and the CCD ID.
110 
111  @param dataRef Data reference from butler. The "CoaddId_bits" and "CoaddId"
112  datasets are accessed. The data ID must have tract and patch keys.
113  """
114  # With the default configuration, this IdFactory doesn't do anything, because
115  # the IDs it generates are immediately overwritten by the ID from the reference
116  # catalog (since that's in config.measurement.copyColumns). But we create one here anyway, to
117  # allow us to revert back to the old behavior of generating new forced source IDs,
118  # just by renaming the ID in config.copyColumns to "object_id".
119  expBits = dataRef.get(self.config.coaddName + "CoaddId_bits")
120  expId = int(dataRef.get(self.config.coaddName + "CoaddId"))
121  return lsst.afw.table.IdFactory.makeSource(expId, 64 - expBits)
122 
123  def getExposureId(self, dataRef):
124  return int(dataRef.get(self.config.coaddName + "CoaddId"))
125 
126  def fetchReferences(self, dataRef, exposure):
127  """Return an iterable of reference sources which overlap the exposure
128 
129  @param dataRef Data reference from butler corresponding to the image to be measured;
130  should have tract, patch, and filter keys.
131  @param exposure lsst.afw.image.Exposure to be measured (not used by this implementation)
132 
133  All work is delegated to the references subtask; see CoaddSrcReferencesTask for information
134  about the default behavior.
135  """
136  skyMap = dataRef.get(self.dataPrefix + "skyMap", immediate=True)
137  tractInfo = skyMap[dataRef.dataId["tract"]]
138  patch = tuple(int(v) for v in dataRef.dataId["patch"].split(","))
139  patchInfo = tractInfo.getPatchInfo(patch)
140  references = lsst.afw.table.SourceCatalog(self.references.schema)
141  references.extend(self.references.fetchInPatches(dataRef, patchList=[patchInfo]))
142  return references
143 
144  def attachFootprints(self, sources, refCat, exposure, refWcs, dataRef):
145  """For coadd forced photometry, we use the deblended HeavyFootprints from the single-band
146  measurements of the same band - because we've guaranteed that the peaks (and hence child sources)
147  will be consistent across all bands before we get to measurement, this should yield reasonable
148  deblending for most sources. It's most likely limitation is that it will not provide good flux
149  upper limits for sources that were not detected in this band but were blended with sources that
150  were.
151  """
152  if self.config.footprintDatasetName is None:
153  return ForcedPhotImageTask.attachFootprints(self, sources, refCat, exposure, refWcs, dataRef)
154  self.log.info("Loading deblended footprints for sources from %s, %s" %
155  (self.config.footprintDatasetName, dataRef.dataId))
156  fpCat = dataRef.get("%sCoadd_%s" % (self.config.coaddName, self.config.footprintDatasetName),
157  immediate=True)
158  for refRecord, srcRecord in zip(refCat, sources):
159  fpRecord = fpCat.find(refRecord.getId())
160  if fpRecord is None:
161  raise LookupError("Cannot find Footprint for source %s; please check that %sCoadd_%s "
162  "IDs are compatible with reference source IDs" %
163  (srcRecord.getId(), self.config.coaddName,
164  self.config.footprintDatasetName))
165  srcRecord.setFootprint(fpRecord.getFootprint())
166 
167  @classmethod
168  def _makeArgumentParser(cls):
169  parser = lsst.pipe.base.ArgumentParser(name=cls._DefaultName)
170  parser.add_id_argument("--id", "deepCoadd_forced_src", help="data ID, with raw CCD keys + tract",
171  ContainerClass=lsst.coadd.utils.CoaddDataIdContainer)
172  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.