LoadReferenceCatalogTask

class lsst.pipe.tasks.loadReferenceCatalog.LoadReferenceCatalogTask(*, dataIds, refCats, name, **kwargs)

Bases: Task

Load multi-band reference objects from a reference catalog.

Parameters

dataIdsiterable of lsst.daf.butler.dataId

An iterable object of dataIds which point to reference catalogs in a Gen3 repository. Required for Gen3.

refCatsiterable of lsst.daf.butler.DeferredDatasetHandle

An iterable object of dataset refs for reference catalogs in a Gen3 repository.

namestr

The name of the refcat that this object will load. This name is used for applying colorterms, for example.

Raises

RuntimeError if dataIds or refCats is None.

Methods Summary

getPixelBoxCatalog(bbox, wcs, filterList[, ...])	Get a multi-band reference catalog by specifying a bounding box and WCS.
getSkyCircleCatalog(center, radius, filterList)	Get a multi-band reference catalog by specifying a center and radius.

Methods Documentation

getPixelBoxCatalog(bbox, wcs, filterList, epoch=None, bboxToSpherePadding=None)

Get a multi-band reference catalog by specifying a bounding box and WCS.

The catalog will be in numpy.ndarray, with positions proper-motion corrected to “epoch” (if specified, and if the reference catalog has proper motions); sources cut on a reference selector (if “config.doReferenceSelection = True”); and color-terms applied (if “config.doApplyColorTerms = True”).

The format of the reference catalog will be of the format:

dtype = [(‘ra’, ‘np.float64’),

(‘dec’, ‘np.float64’), (‘refMag’, ‘np.float32’, (len(filterList), )), (‘refMagErr’, ‘np.float32’, (len(filterList), ))]

Reference magnitudes (AB) and errors will be NaN for non-detections in a given band.

Parameters

bboxlsst.geom.Box2I

Box which bounds a region in pixel space.

wcslsst.afw.geom.SkyWcs

Wcs object defining the pixel to sky (and reverse) transform for the supplied bbox.

filterListList [ str ]

List of camera physicalFilter names to retrieve magnitudes.

epochastropy.time.Time, optional

Epoch to which to correct proper motion and parallax (if available), or None to not apply such corrections.

bboxToSpherePaddingint, optional

Padding to account for translating a set of corners into a spherical (convex) boundary that is certain to encompass the entire area covered by the bbox.

Returns

refCatnumpy.ndarray

Reference catalog.

getSkyCircleCatalog(center, radius, filterList, epoch=None, catalogFormat='numpy')

Get a multi-band reference catalog by specifying a center and radius.

The catalog will be in numpy.ndarray, with positions proper-motion corrected to “epoch” (if specified, and if the reference catalog has proper motions); sources cut on a reference selector (if “config.doReferenceSelection = True”); and color-terms applied (if “config.doApplyColorTerms = True”).

The format of the reference catalog will be of the format:

dtype = [(‘ra’, ‘np.float64’),

(‘dec’, ‘np.float64’), (‘refMag’, ‘np.float32’, (len(filterList), )), (‘refMagErr’, ‘np.float32’, (len(filterList), ))]

Reference magnitudes (AB) and errors will be NaN for non-detections in a given band.

Parameters

centerlsst.geom.SpherePoint

Point defining the center of the circular region.

radiuslsst.geom.Angle

Defines the angular radius of the circular region.

filterListList [ str ]

List of camera physicalFilter names to retrieve magnitudes.

epochastropy.time.Time, optional

Epoch to which to correct proper motion and parallax (if available), or None to not apply such corrections.

Returns

refCatnumpy.ndarray

Reference catalog.