BrightStarStamp¶
- class lsst.meas.algorithms.BrightStarStamp(stamp_im: MaskedImageF, gaiaGMag: float, gaiaId: int, position: Point2I, archive_element: Persistable | None = None, annularFlux: float | None = None, minValidAnnulusFraction: float = 0.0, validAnnulusFraction: float | None = None, optimalInnerRadius: int | None = None, optimalOuterRadius: int | None = None)¶
Bases:
AbstractStamp
Single stamp centered on a bright star, normalized by its annularFlux.
- Parameters:
- stamp_im
MaskedImage
Pixel data for this postage stamp
- gaiaGMag
float
Gaia G magnitude for the object in this stamp
- gaiaId
int
Gaia object identifier
- position
Point2I
Origin of the stamps in its origin exposure (pixels)
- archive_element
Persistable
or None, optional Archive element (e.g. Transform or WCS) associated with this stamp.
- annularFlux
float
or None, optional Flux in an annulus around the object
- stamp_im
Attributes Summary
Methods Summary
factory
(stamp_im, metadata, idx[, ...])This method is needed to service the FITS reader.
measureAndNormalize
(annulus[, statsControl, ...])Compute "annularFlux", the integrated flux within an annulus around an object's center, and normalize it.
Attributes Documentation
- archive_element: Persistable | None = None¶
Methods Documentation
- classmethod factory(stamp_im, metadata, idx, archive_element=None, minValidAnnulusFraction=0.0)¶
This method is needed to service the FITS reader. We need a standard interface to construct objects like this. Parameters needed to construct this object are passed in via a metadata dictionary and then passed to the constructor of this class. This particular factory method requires keys: G_MAGS, GAIA_IDS, and ANNULAR_FLUXES. They should each point to lists of values.
- Parameters:
- stamp_im
MaskedImage
Pixel data to pass to the constructor
- metadata
dict
Dictionary containing the information needed by the constructor.
- idx
int
Index into the lists in
metadata
- archive_element
Persistable
or None, optional Archive element (e.g. Transform or WCS) associated with this stamp.
- minValidAnnulusFraction
float
, optional The fraction of valid pixels within the normalization annulus of a star.
- stamp_im
- Returns:
- brightstarstamp
BrightStarStamp
An instance of this class
- brightstarstamp
- measureAndNormalize(annulus: ~lsst.afw.geom.SpanSet, statsControl: ~lsst.afw.math.StatisticsControl = <lsst.afw.math.StatisticsControl object>, statsFlag: ~lsst.afw.math.Property = <Property.MEAN: 4>, badMaskPlanes: ~collections.abc.Collection[str] = ('BAD', 'SAT', 'NO_DATA'))¶
Compute “annularFlux”, the integrated flux within an annulus around an object’s center, and normalize it.
Since the center of bright stars are saturated and/or heavily affected by ghosts, we measure their flux in an annulus with a large enough inner radius to avoid the most severe ghosts and contain enough non-saturated pixels.
- Parameters:
- annulus
SpanSet
SpanSet containing the annulus to use for normalization.
- statsControl
StatisticsControl
, optional StatisticsControl to be used when computing flux over all pixels within the annulus.
- statsFlag
Property
, optional statsFlag to be passed on to
afwMath.makeStatistics
to compute annularFlux. Defaults to a simple MEAN.- badMaskPlanes
collections.abc.Collection
[str
] Collection of mask planes to ignore when computing annularFlux.
- annulus