lsst.meas.base.forcedPhotCoadd.ForcedPhotCoaddTask Class Reference

Inheritance diagram for lsst.meas.base.forcedPhotCoadd.ForcedPhotCoaddTask:

Public Member Functions
def	getExposure (self, dataRef)
def	makeIdFactory (self, dataRef)
def	getExposureId (self, dataRef)
def	fetchReferences (self, dataRef, exposure)
def	attachFootprints (self, sources, refCat, exposure, refWcs, dataRef)

Static Public Attributes
	ConfigClass = ForcedPhotCoaddConfig
	RunnerClass = lsst.pipe.base.ButlerInitializedTaskRunner
string	dataPrefix = "deepCoadd_"

Detailed Description

A command-line driver for performing forced measurement on coadd images.

Notes
-----
In addition to the run method, `ForcedPhotCcdTask` overrides several
methods of `ForcedPhotImageTask` to specialize it for coadd processing,
including `~ForcedPhotImageTask.makeIdFactory` and
`~ForcedPhotImageTask.fetchReferences`. None of these should be called
directly by the user, though it may be useful to override them further in
subclasses.

Definition at line 80 of file forcedPhotCoadd.py.

Member Function Documentation

attachFootprints()

def lsst.meas.base.forcedPhotCoadd.ForcedPhotCoaddTask.attachFootprints	(		self,
			sources,
			refCat,
			exposure,
			refWcs,
			dataRef
	)

Attach Footprints to source records.

For coadd forced photometry, we use the deblended "heavy"
`~lsst.afw.detection.Footprint`\ s from the single-band measurements
of the same band - because we've guaranteed that the peaks (and hence
child sources) will be consistent across all bands before we get to
measurement, this should yield reasonable deblending for most sources.
It's most likely limitation is that it will not provide good flux
upper limits for sources that were not detected in this band but were
blended with sources that were.

Definition at line 158 of file forcedPhotCoadd.py.

    def attachFootprints(self, sources, refCat, exposure, refWcs, dataRef):
        r"""Attach Footprints to source records.
 
        For coadd forced photometry, we use the deblended "heavy"
        `~lsst.afw.detection.Footprint`\ s from the single-band measurements
        of the same band - because we've guaranteed that the peaks (and hence
        child sources) will be consistent across all bands before we get to
        measurement, this should yield reasonable deblending for most sources.
        It's most likely limitation is that it will not provide good flux
        upper limits for sources that were not detected in this band but were
        blended with sources that were.
        """
        if self.config.footprintDatasetName is None:
            return ForcedPhotImageTask.attachFootprints(self, sources, refCat, exposure, refWcs, dataRef)
        self.log.info("Loading deblended footprints for sources from %s, %s" %
                      (self.config.footprintDatasetName, dataRef.dataId))
        fpCat = dataRef.get("%sCoadd_%s" % (self.config.coaddName, self.config.footprintDatasetName),
                            immediate=True)
        for refRecord, srcRecord in zip(refCat, sources):
            fpRecord = fpCat.find(refRecord.getId())
            if fpRecord is None:
                raise LookupError("Cannot find Footprint for source %s; please check that %sCoadd_%s "
                                  "IDs are compatible with reference source IDs" %
                                  (srcRecord.getId(), self.config.coaddName,
                                   self.config.footprintDatasetName))
            srcRecord.setFootprint(fpRecord.getFootprint())
 

fetchReferences()

def lsst.meas.base.forcedPhotCoadd.ForcedPhotCoaddTask.fetchReferences	(		self,
			dataRef,
			exposure
	)

Return an iterable of reference sources which overlap the exposure.

Parameters
----------
dataRef : `lsst.daf.persistence.ButlerDataRef`
    Butler data reference corresponding to the image to be measured;
    should have tract, patch, and filter keys.

exposure : `lsst.afw.image.Exposure`
    Unused.

Notes
-----
All work is delegated to the references subtask; see
`CoaddSrcReferencesTask` for information about the default behavior.

Definition at line 133 of file forcedPhotCoadd.py.

    def fetchReferences(self, dataRef, exposure):
        """Return an iterable of reference sources which overlap the exposure.
 
        Parameters
        ----------
        dataRef : `lsst.daf.persistence.ButlerDataRef`
            Butler data reference corresponding to the image to be measured;
            should have tract, patch, and filter keys.
 
        exposure : `lsst.afw.image.Exposure`
            Unused.
 
        Notes
        -----
        All work is delegated to the references subtask; see
        `CoaddSrcReferencesTask` for information about the default behavior.
        """
        skyMap = dataRef.get(self.dataPrefix + "skyMap", immediate=True)
        tractInfo = skyMap[dataRef.dataId["tract"]]
        patch = tuple(int(v) for v in dataRef.dataId["patch"].split(","))
        patchInfo = tractInfo.getPatchInfo(patch)
        references = lsst.afw.table.SourceCatalog(self.references.schema)
        references.extend(self.references.fetchInPatches(dataRef, patchList=[patchInfo]))
        return references
 

getExposure()

def lsst.meas.base.forcedPhotCoadd.ForcedPhotCoaddTask.getExposure	(		self,
			dataRef
	)

Definition at line 98 of file forcedPhotCoadd.py.

    def getExposure(self, dataRef):
 
        if self.config.hasFakes:
            name = "fakes_" + self.config.coaddName + "Coadd_calexp"
        else:
            name = self.config.coaddName + "Coadd_calexp"
 
        return dataRef.get(name) if dataRef.datasetExists(name) else None
 

getExposureId()

def lsst.meas.base.forcedPhotCoadd.ForcedPhotCoaddTask.getExposureId	(		self,
			dataRef
	)

Definition at line 130 of file forcedPhotCoadd.py.

    def getExposureId(self, dataRef):
        return int(dataRef.get(self.config.coaddName + "CoaddId"))
 

makeIdFactory()

def lsst.meas.base.forcedPhotCoadd.ForcedPhotCoaddTask.makeIdFactory	(		self,
			dataRef
	)

Create an object that generates globally unique source IDs.

Source IDs are created based on a per-CCD ID and the ID of the CCD
itself.

Parameters
----------
dataRef : `lsst.daf.persistence.ButlerDataRef`
    Butler data reference. The "CoaddId_bits" and "CoaddId" datasets
    are accessed. The data ID must have tract and patch keys.

Definition at line 107 of file forcedPhotCoadd.py.

    def makeIdFactory(self, dataRef):
        """Create an object that generates globally unique source IDs.
 
        Source IDs are created based on a per-CCD ID and the ID of the CCD
        itself.
 
        Parameters
        ----------
        dataRef : `lsst.daf.persistence.ButlerDataRef`
            Butler data reference. The "CoaddId_bits" and "CoaddId" datasets
            are accessed. The data ID must have tract and patch keys.
        """
        # With the default configuration, this IdFactory doesn't do anything,
        # because the IDs it generates are immediately overwritten by the ID
        # from the reference catalog (since that's in
        # config.measurement.copyColumns).  But we create one here anyway, to
        # allow us to revert back to the old behavior of generating new forced
        # source IDs, just by renaming the ID in config.copyColumns to
        # "object_id".
        expBits = dataRef.get(self.config.coaddName + "CoaddId_bits")
        expId = int(dataRef.get(self.config.coaddName + "CoaddId"))
        return lsst.afw.table.IdFactory.makeSource(expId, 64 - expBits)
 

Member Data Documentation

ConfigClass

lsst.meas.base.forcedPhotCoadd.ForcedPhotCoaddTask.ConfigClass = ForcedPhotCoaddConfig

static

Definition at line 93 of file forcedPhotCoadd.py.

dataPrefix

string lsst.meas.base.forcedPhotCoadd.ForcedPhotCoaddTask.dataPrefix = "deepCoadd_"

static

Definition at line 96 of file forcedPhotCoadd.py.

RunnerClass

lsst.meas.base.forcedPhotCoadd.ForcedPhotCoaddTask.RunnerClass = lsst.pipe.base.ButlerInitializedTaskRunner

static

Definition at line 94 of file forcedPhotCoadd.py.

---

The documentation for this class was generated from the following file:

• /j/snowflake/release/lsstsw/stack/0.4.1/Linux64/meas_base/21.0.0-5-g073e055+57e5e98977/python/lsst/meas/base/forcedPhotCoadd.py