lsst.meas.astrom  21.0.0-4-g591bb35+2e2638e9ee
Public Member Functions | Static Public Attributes | List of all members
lsst.meas.astrom.fitAffineWcs.FitAffineWcsTask Class Reference
Inheritance diagram for lsst.meas.astrom.fitAffineWcs.FitAffineWcsTask:

Public Member Functions

def fitWcs (self, matches, initWcs, bbox=None, refCat=None, sourceCat=None, exposure=None)
 

Static Public Attributes

 ConfigClass = FitAffineWcsConfig
 

Detailed Description

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

This WCS fitter should be used on top of a cameraGeom distortion model as
the model assumes that only a shift the WCS center position and a small
affine transform are required.

Definition at line 94 of file fitAffineWcs.py.

Member Function Documentation

◆ fitWcs()

def lsst.meas.astrom.fitAffineWcs.FitAffineWcsTask.fitWcs (   self,
  matches,
  initWcs,
  bbox = None,
  refCat = None,
  sourceCat = None,
  exposure = None 
)
Fit a simple Affine transform with a shift to the matches and update
the WCS.

This method assumes that the distortion model of the telescope is
applied correctly and is accurate with only a slight rotation,
rotation, and "squish" required to fit to the reference locations.

Parameters
----------
matches : `list` of `lsst.afw.table.ReferenceMatch`
    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`
    initial WCS
bbox : `lsst.geom.Box2I`
    Ignored; present for consistency with FitSipDistortionTask.
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 fields are "slot_Centroid_x", "slot_Centroid_y", and
    "coord_ra", and "coord_dec".
exposure : `lsst.afw.image.Exposure`
    Ignored; present for consistency with FitSipDistortionTask.

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

    - ``wcs`` :  the fit WCS (`lsst.afw.geom.SkyWcs`)
    - ``scatterOnSky`` :  median on-sky separation between reference
      objects and sources in "matches" (`lsst.afw.geom.Angle`)

Definition at line 105 of file fitAffineWcs.py.

Member Data Documentation

◆ ConfigClass

lsst.meas.astrom.fitAffineWcs.FitAffineWcsTask.ConfigClass = FitAffineWcsConfig
static

Definition at line 101 of file fitAffineWcs.py.


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