lsst.meas.astrom  21.0.0-3-g6d51c4a+905c13b855
Public Member Functions | Public Attributes | Static Public Attributes | List of all members
lsst.meas.astrom.fitSipDistortion.FitSipDistortionTask Class Reference
Inheritance diagram for lsst.meas.astrom.fitSipDistortion.FitSipDistortionTask:

Public Member Functions

def __init__ (self, **kwargs)
 
def fitWcs (self, matches, initWcs, bbox=None, refCat=None, sourceCat=None, exposure=None)
 
def display (self, revFitter, exposure=None, bbox=None, frame=0, pause=True)
 
def makeInitialWcs (self, matches, wcs)
 

Public Attributes

 outlierRejectionCtrl
 

Static Public Attributes

 ConfigClass = FitSipDistortionConfig
 

Detailed Description

Fit a TAN-SIP WCS given a list of reference object/source matches.

Definition at line 101 of file fitSipDistortion.py.

Constructor & Destructor Documentation

◆ __init__()

def lsst.meas.astrom.fitSipDistortion.FitSipDistortionTask.__init__ (   self,
**  kwargs 
)

Definition at line 107 of file fitSipDistortion.py.

Member Function Documentation

◆ display()

def lsst.meas.astrom.fitSipDistortion.FitSipDistortionTask.display (   self,
  revFitter,
  exposure = None,
  bbox = None,
  frame = 0,
  pause = True 
)
Display positions and outlier status overlaid on an image.

This method is called by fitWcs when display debugging is enabled.  It
always drops into pdb before returning to allow interactive inspection,
and hence it should never be called in non-interactive contexts.

Parameters
----------
revFitter : :cpp:class:`lsst::meas::astrom::ScaledPolynomialTransformFitter`
    Fitter object initialized with `fromMatches` for fitting a "reverse"
    distortion: the mapping from intermediate world coordinates to
    pixels.
exposure : :cpp:class:`lsst::afw::image::Exposure`
    An Exposure or other displayable image on which matches can be
    overplotted.
bbox : :cpp:class:`lsst::afw::geom::Box2I`
    Bounding box of the region on which matches should be plotted.

Definition at line 263 of file fitSipDistortion.py.

◆ fitWcs()

def lsst.meas.astrom.fitSipDistortion.FitSipDistortionTask.fitWcs (   self,
  matches,
  initWcs,
  bbox = None,
  refCat = None,
  sourceCat = None,
  exposure = None 
)
Fit a TAN-SIP WCS from a list of reference object/source matches.

Parameters
----------
matches : `list` of `lsst.afw.table.ReferenceMatch`
    A sequence of reference object/source matches.
    The following fields are read:
    - match.first (reference object) coord
    - match.second (source) centroid

    The following fields are written:
    - match.first (reference object) centroid
    - match.second (source) centroid
    - match.distance (on sky separation, in radians)

initWcs : `lsst.afw.geom.SkyWcs`
    An initial WCS whose CD matrix is used as the final CD matrix.
bbox : `lsst.geom.Box2I`
    The region over which the WCS will be valid (PARENT pixel coordinates);
    if `None` or an empty box then computed from matches
refCat : `lsst.afw.table.SimpleCatalog`
    Reference object catalog, or `None`.
    If provided then all centroids are updated with the new WCS,
    otherwise only the centroids for ref objects in matches are updated.
    Required fields are "centroid_x", "centroid_y", "coord_ra", and "coord_dec".
sourceCat : `lsst.afw.table.SourceCatalog`
    Source catalog, or `None`.
    If provided then coords are updated with the new WCS;
    otherwise only the coords for sources in matches are updated.
    Required input fields are "slot_Centroid_x", "slot_Centroid_y",
    "slot_Centroid_xErr", "slot_Centroid_yErr", and optionally
    "slot_Centroid_x_y_Cov".  The "coord_ra" and "coord_dec" fields
    will be updated but are not used as input.
exposure : `lsst.afw.image.Exposure`
    An Exposure or other displayable image on which matches can be
    overplotted.  Ignored (and may be `None`) if display-based debugging
    is not enabled via lsstDebug.

Returns
-------
An lsst.pipe.base.Struct with the following fields:
    - wcs : `lsst.afw.geom.SkyWcs`
The best-fit WCS.
    - scatterOnSky : `lsst.geom.Angle`
The median on-sky separation between reference objects and
sources in "matches", as an `lsst.geom.Angle`

Definition at line 115 of file fitSipDistortion.py.

◆ makeInitialWcs()

def lsst.meas.astrom.fitSipDistortion.FitSipDistortionTask.makeInitialWcs (   self,
  matches,
  wcs 
)
Generate a guess Wcs from the astrometric matches

We create a Wcs anchored at the center of the matches, with the scale
of the input Wcs.  This is necessary because the Wcs may have a very
approximation position (as is common with telescoped-generated Wcs).
We're using the best of each: positions from the matches, and scale
from the input Wcs.

Parameters
----------
matches : list of :cpp:class:`lsst::afw::table::ReferenceMatch`
    A sequence of reference object/source matches.
    The following fields are read:

    - match.first (reference object) coord
    - match.second (source) centroid

wcs : :cpp:class:`lsst::afw::geom::SkyWcs`
    An initial WCS whose CD matrix is used as the CD matrix of the
    result.

Returns
-------
newWcs : `lsst.afw.geom.SkyWcs`
    A new WCS guess.

Definition at line 318 of file fitSipDistortion.py.

Member Data Documentation

◆ ConfigClass

lsst.meas.astrom.fitSipDistortion.FitSipDistortionTask.ConfigClass = FitSipDistortionConfig
static

Definition at line 104 of file fitSipDistortion.py.

◆ outlierRejectionCtrl

lsst.meas.astrom.fitSipDistortion.FitSipDistortionTask.outlierRejectionCtrl

Definition at line 109 of file fitSipDistortion.py.


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