lsst.meas.astrom g71f27ac40c+2ced63db88
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Public Member Functions | Public Attributes | Static Public Attributes | List of all members
lsst.meas.astrom.astrometry.AstrometryTask Class Reference
Inheritance diagram for lsst.meas.astrom.astrometry.AstrometryTask:
lsst.meas.astrom.ref_match.RefMatchTask

Public Member Functions

def __init__ (self, refObjLoader, schema=None, **kwargs)
 
def run (self, sourceCat, exposure)
 
def solve (self, exposure, sourceCat)
 

Public Attributes

 usedKey
 

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 100 of file astrometry.py.

Constructor & Destructor Documentation

◆ __init__()

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

Reimplemented from lsst.meas.astrom.ref_match.RefMatchTask.

Definition at line 121 of file astrometry.py.

Member Function Documentation

◆ 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
    - 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 133 of file astrometry.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`)

Raises
------
TaskError
    If the measured mean on-sky distance between the matched source and
    reference objects is greater than
    ``self.config.maxMeanDistanceArcsec``.

Notes
-----
ignores config.forceKnownWcs

Definition at line 182 of file astrometry.py.

Member Data Documentation

◆ ConfigClass

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

Definition at line 118 of file astrometry.py.

◆ usedKey

lsst.meas.astrom.astrometry.AstrometryTask.usedKey

Definition at line 125 of file astrometry.py.


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