Match sources to reference objects. More...

Inheritance diagram for lsst.meas.astrom.matchOptimisticB.matchOptimisticBContinued.MatchOptimisticBTask:

Public Member Functions
def	__init__ (self, kwargs)

def	filterStars (self, refCat)

def	matchObjectsToSources (self, refCat, sourceCat, wcs, refFluxField, match_tolerance=None)
	Match sources to position reference stars. More...

Public Attributes
	edgeKey

	interpolatedCenterKey

	saturatedKey

Static Public Attributes
	ConfigClass = MatchOptimisticBConfig

Detailed Description

Match sources to reference objects.

Description

Match sources to reference objects. This is often done as a preliminary step to fitting an astrometric or photometric solution. For details about the matching algorithm see matchOptimisticB.h

Task initialisation

Invoking the Task

Match sources to position reference stars.

Parameters

[in]	refCat	catalog of reference objects that overlap the exposure; reads fields for: coord the specified flux field
[in]	sourceCat	catalog of sources found on an exposure; reads fields for: centroid centroid flag edge flag saturated flag aperture flux, if found, else PSF flux
[in]	wcs	estimated WCS
[in]	refFluxField	field of refCat to use for flux
[in]	match_tolerance	a MatchTolerance object for specifying tolerances. Must at minimum contain a lsst.afw.geom.Angle called maxMatchDist that communicates state between AstrometryTask and the matcher Task.

Returns

an lsst.pipe.base.Struct with fields:

matches a list of matches, each instance of lsst.afw.table.ReferenceMatch
usableSourcCat a catalog of sources potentially usable for matching. For this fitter usable sources include unresolved sources not too near the edge. It includes saturated sources, even those these are removed from the final match list, because saturated sources may be used to determine the match list.

Configuration parameters

See MatchOptimisticBConfig

To modify how usable sources are selected, specify a different source selector in config.sourceSelector.

A complete example of using MatchOptimisticBTask

MatchOptimisticBTask is a subtask of AstrometryTask, which is called by PhotoCalTask. See pipe_tasks_photocal_Example.

Debug variables

The command line task interface supports a flag -d to import debug.py from your PYTHONPATH; see Using lsstDebug to control debugging output for more about debug.py files.

The available variables in MatchOptimisticBTask are:

verbose (bool): If True then the matcher prints debug messages to stdout

To investigate the Debug variables, put something like

import lsstDebug
def DebugInfo(name):
    debug = lsstDebug.getInfo(name)        # N.b. lsstDebug.Info(name) would call us recursively
    if name == "lsst.pipe.tasks.astrometry":
        debug.verbose = True
    return debug
lsstDebug.Info = DebugInfo

into your debug.py file and run this task with the –debug flag.

Definition at line 117 of file matchOptimisticBContinued.py.

Constructor & Destructor Documentation

◆ init()

def lsst.meas.astrom.matchOptimisticB.matchOptimisticBContinued.MatchOptimisticBTask.__init__	(	self,
		kwargs
	)

Definition at line 185 of file matchOptimisticBContinued.py.

Member Function Documentation

◆ filterStars()

def lsst.meas.astrom.matchOptimisticB.matchOptimisticBContinued.MatchOptimisticBTask.filterStars	(	self,
		refCat
	)

Extra filtering pass; subclass if desired

Definition at line 189 of file matchOptimisticBContinued.py.

◆ matchObjectsToSources()

def lsst.meas.astrom.matchOptimisticB.matchOptimisticBContinued.MatchOptimisticBTask.matchObjectsToSources	(	self,
		refCat,
		sourceCat,
		wcs,
		refFluxField,
		match_tolerance = `None`
	)

Match sources to position reference stars.

Parameters

[in]	refCat	catalog of reference objects that overlap the exposure; reads fields for: coord the specified flux field
[in]	sourceCat	catalog of sources found on an exposure; reads fields for: centroid centroid flag edge flag saturated flag aperture flux, if found, else PSF flux
[in]	wcs	estimated WCS
[in]	refFluxField	field of refCat to use for flux
[in]	match_tolerance	a MatchTolerance object for specifying tolerances. Must at minimum contain a lsst.afw.geom.Angle called maxMatchDist that communicates state between AstrometryTask and the matcher Task.

Returns

an lsst.pipe.base.Struct with fields:

matches a list of matches, each instance of lsst.afw.table.ReferenceMatch
usableSourcCat a catalog of sources potentially usable for matching. For this fitter usable sources include unresolved sources not too near the edge. It includes saturated sources, even those these are removed from the final match list, because saturated sources may be used to determine the match list.

Definition at line 196 of file matchOptimisticBContinued.py.