lsst.meas.astrom.astrometry.AstrometryTask Class Reference

Inheritance diagram for lsst.meas.astrom.astrometry.AstrometryTask:

Public Member Functions
def	__init__ (self, refObjLoader, schema=None, kwargs)
def	run (self, sourceCat, exposure)
def	solve (self, exposure, sourceCat)
def	setRefObjLoader (self, refObjLoader)
def	loadAndMatch (self, exposure, sourceCat)

Public Attributes
	usedKey
	refObjLoader

Static Public Attributes
	ConfigClass = AstrometryConfig

Detailed Description

Match an input source catalog with objects from a reference catalog and
solve for the WCS.

This task is broken into two main subasks: matching and WCS fitting which
are very interactive. The matching here can be considered in part a first
pass WCS fitter due to the fitter's sensitivity to outliers.

Parameters
----------
refObjLoader : `lsst.meas.algorithms.ReferenceLoader`
    A reference object loader object
schema : `lsst.afw.table.Schema`
    Used to set "calib_astrometry_used" flag in output source catalog.
**kwargs
    additional keyword arguments for pipe_base
    `lsst.pipe.base.Task.__init__`

Definition at line 73 of file astrometry.py.

Constructor & Destructor Documentation

__init__()

def lsst.meas.astrom.astrometry.AstrometryTask.__init__	(		self,
			refObjLoader,
			schema = None,
			kwargs
	)

Definition at line 94 of file astrometry.py.

Member Function Documentation

loadAndMatch()

def lsst.meas.astrom.ref_match.RefMatchTask.loadAndMatch (   self,   exposure,   sourceCat  )

inherited

Load reference objects overlapping an exposure and match to sources
detected on that exposure.

Parameters
----------
exposure : `lsst.afw.image.Exposure`
    exposure that the sources overlap
sourceCat : `lsst.afw.table.SourceCatalog.`
    catalog of sources detected on the exposure

Returns
-------
result : `lsst.pipe.base.Struct`
    Result struct with Components:

    - ``refCat`` : reference object catalog of objects that overlap the
      exposure (`lsst.afw.table.SimpleCatalog`)
    - ``matches`` :  Matched sources and references
      (`list` of `lsst.afw.table.ReferenceMatch`)
    - ``matchMeta`` : metadata needed to unpersist matches
      (`lsst.daf.base.PropertyList`)

Notes
-----
ignores config.matchDistanceSigma

Definition at line 116 of file ref_match.py.

run()

def lsst.meas.astrom.astrometry.AstrometryTask.run	(		self,
			sourceCat,
			exposure
	)

Load reference objects, match sources and optionally fit a WCS.

This is a thin layer around solve or loadAndMatch, depending on
config.forceKnownWcs.

Parameters
----------
exposure : `lsst.afw.image.Exposure`
    exposure whose WCS is to be fit
    The following are read only:

    - bbox
    - photoCalib (may be absent)
    - filter (may be unset)
    - detector (if wcs is pure tangent; may be absent)

    The following are updated:

    - wcs (the initial value is used as an initial guess, and is
      required)

sourceCat : `lsst.afw.table.SourceCatalog`
    catalog of sources detected on the exposure

Returns
-------
result : `lsst.pipe.base.Struct`
    with these fields:

    - ``refCat`` : reference object catalog of objects that overlap the
      exposure (with some margin) (`lsst.afw.table.SimpleCatalog`).
    - ``matches`` : astrometric matches
      (`list` of `lsst.afw.table.ReferenceMatch`).
    - ``scatterOnSky`` :  median on-sky separation between reference
      objects and sources in "matches"
      (`lsst.afw.geom.Angle`) or `None` if config.forceKnownWcs True
    - ``matchMeta`` :  metadata needed to unpersist matches
      (`lsst.daf.base.PropertyList`)

Definition at line 106 of file astrometry.py.

setRefObjLoader()

def lsst.meas.astrom.ref_match.RefMatchTask.setRefObjLoader (   self,   refObjLoader  )

inherited

Sets the reference object loader for the task

Parameters
----------
refObjLoader
    An instance of a reference object loader task or class

Definition at line 105 of file ref_match.py.

solve()

def lsst.meas.astrom.astrometry.AstrometryTask.solve	(		self,
			exposure,
			sourceCat
	)

Load reference objects overlapping an exposure, match to sources and
fit a WCS

Returns
-------
result : `lsst.pipe.base.Struct`
    Result struct with components:

    - ``refCat`` : reference object catalog of objects that overlap the
      exposure (with some margin) (`lsst::afw::table::SimpleCatalog`).
    - ``matches`` :  astrometric matches
      (`list` of `lsst.afw.table.ReferenceMatch`).
    - ``scatterOnSky`` :  median on-sky separation between reference
      objects and sources in "matches" (`lsst.geom.Angle`)
    - ``matchMeta`` :  metadata needed to unpersist matches
      (`lsst.daf.base.PropertyList`)

Notes
-----
ignores config.forceKnownWcs

Definition at line 156 of file astrometry.py.

Member Data Documentation

ConfigClass

lsst.meas.astrom.astrometry.AstrometryTask.ConfigClass = AstrometryConfig

static

Definition at line 91 of file astrometry.py.

refObjLoader

lsst.meas.astrom.ref_match.RefMatchTask.refObjLoader

inherited

Definition at line 92 of file ref_match.py.

usedKey

lsst.meas.astrom.astrometry.AstrometryTask.usedKey

Definition at line 98 of file astrometry.py.

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

• python/lsst/meas/astrom/astrometry.py