MatchPessimisticBConfig#

class lsst.meas.astrom.MatchPessimisticBConfig(*args, **kw)#

Bases: Config

Configuration for MatchPessimisticBTask

Attributes Summary

`matcherIterations`	Number of softening iterations in matcher.
`maxOffsetPix`	Maximum allowed shift of WCS, due to matching (pixel).
`maxRefObjects`	Maximum number of reference objects to use for the matcher.
`maxRotationDeg`	Rotation angle allowed between sources and position reference objects (degrees).
`minFracMatchedPairs`	Minimum number of matched pairs as a fraction of the smaller of the number of reference stars or the number of good sources; the actual minimum is the smaller of this value or minMatchedPairs.
`minMatchDistPixels`	Distance in units of pixels to always consider a source-reference pair a match.
`minMatchedPairs`	Minimum number of matched pairs; see also minFracMatchedPairs.
`numBrightStars`	Maximum number of bright stars to use.
`numPatternConsensus`	Number of implied shift/rotations from patterns that must agree before it a given shift/rotation is accepted.
`numPointsForShape`	Number of points to define a shape for matching.
`numPointsForShapeAttempt`	Number of points to try for creating a shape.
`numRefRequireConsensus`	If the available reference objects exceeds this number, consensus/pessimistic mode will enforced regardless of the number of available sources.

Methods Summary

validate()

Validate the Config, raising an exception if invalid.

Attributes Documentation

matcherIterations#

Number of softening iterations in matcher. (int, default 5)

Valid Range = [1,inf)

maxOffsetPix#

Maximum allowed shift of WCS, due to matching (pixel). When changing this value, the LoadReferenceObjectsConfig.pixelMargin should also be updated. (int, default 250)

Valid Range = [-inf,4000)

maxRefObjects#

Maximum number of reference objects to use for the matcher. The absolute maximum allowed for is 2 ** 16 for memory reasons. (int, default 8192)

Valid Range = [0,65537)

maxRotationDeg#

Rotation angle allowed between sources and position reference objects (degrees). (float, default 1.0)

Valid Range = [-inf,6.0)

minFracMatchedPairs#

Minimum number of matched pairs as a fraction of the smaller of the number of reference stars or the number of good sources; the actual minimum is the smaller of this value or minMatchedPairs. (float, default 0.3)

Valid Range = [0,1)

minMatchDistPixels#

Distance in units of pixels to always consider a source-reference pair a match. This prevents the astrometric fitter from over-fitting and removing stars that should be matched and allows for inclusion of new matches as the wcs improves. (float, default 1.0)

Valid Range = [0.0,6.0)

minMatchedPairs#

Minimum number of matched pairs; see also minFracMatchedPairs. (int, default 30)

Valid Range = [2,inf)

numBrightStars#

Maximum number of bright stars to use. Sets the max number of patterns that can be tested. (int, default 150)

Valid Range = [2,inf)

numPatternConsensus#: Number of implied shift/rotations from patterns that must agree before it a given shift/rotation is accepted. This is only used after the first softening iteration fails and if both the number of reference and source objects is greater than numBrightStars. (int, default 3)

numPointsForShape#: Number of points to define a shape for matching. (int, default 6)

numPointsForShapeAttempt#: Number of points to try for creating a shape. This value should be greater than or equal to numPointsForShape. Besides loosening the signal to noise cut in the ‘matcher’ SourceSelector, increasing this number will solve CCDs where no match was found. (int, default 6)

numRefRequireConsensus#: If the available reference objects exceeds this number, consensus/pessimistic mode will enforced regardless of the number of available sources. Below this optimistic mode (exit at first match rather than requiring numPatternConsensus to be matched) can be used. If more sources are required to match, decrease the signal to noise cut in the sourceSelector. (int, default 1000)

Methods Documentation

validate()#

Validate the Config, raising an exception if invalid.

Raises#

lsst.pex.config.FieldValidationError: Raised if verification fails.

Notes#

The base class implementation performs type checks on all fields by calling their validate methods.

Complex single-field validation can be defined by deriving new Field types. For convenience, some derived lsst.pex.config.Field-types (ConfigField and ConfigChoiceField) are defined in lsst.pex.config that handle recursing into subconfigs.

Inter-field relationships should only be checked in derived Config classes after calling this method, and base validation is complete.