ReferenceObjectLoaderBase¶
- class lsst.meas.algorithms.ReferenceObjectLoaderBase(config=None, *args, **kwargs)¶
Bases:
object
Base class for reference object loaders, to facilitate gen2/gen3 code sharing.
- Parameters:
- config
lsst.pex.config.Config
Configuration for the loader.
- config
Methods Summary
applyProperMotions
(catalog, epoch)Apply proper motion correction to a reference catalog.
getMetadataBox
(bbox, wcs, filterName[, ...])Return metadata about the load
getMetadataCircle
(coord, radius, filterName)Return metadata about the reference catalog being loaded.
joinMatchListWithCatalog
(matchCat, sourceCat)Relink an unpersisted match list to sources and reference objects.
makeMinimalSchema
(filterNameList, *[, ...])Make a standard schema for reference object catalogs.
Methods Documentation
- applyProperMotions(catalog, epoch)¶
Apply proper motion correction to a reference catalog.
Adjust position and position error in the
catalog
for proper motion to the specifiedepoch
, modifying the catalog in place.- Parameters:
- catalog
lsst.afw.table.SimpleCatalog
Catalog of positions, containing at least these fields:
Coordinates, retrieved by the table’s coordinate key.
coord_raErr
: Error in Right Ascension (rad).coord_decErr
: Error in Declination (rad).pm_ra
Proper motion in Right Ascension (rad/yr,East positive)
pm_raErr
: Error inpm_ra
(rad/yr), optional.pm_dec
Proper motion in Declination (rad/yr,North positive)
pm_decErr
: Error inpm_dec
(rad/yr), optional.epoch
: Mean epoch of object (an astropy.time.Time)
- epoch
astropy.time.Time
Epoch to which to correct proper motion. If None, do not apply PM corrections or raise if
config.requireProperMotion
is True.
- catalog
- Raises:
- RuntimeError
Raised if
config.requireProperMotion
is set but we cannot apply the proper motion correction for some reason.
- getMetadataBox(bbox, wcs, filterName, epoch=None, bboxToSpherePadding=100)¶
Return metadata about the load
This metadata is used for reloading the catalog (e.g., for reconstituting a normalised match list).
- Parameters:
- bbox
lsst.geom.Box2I
orlsst.geom.Box2D
Bounding box for the pixels.
- wcs
lsst.afw.geom.SkyWcs
The WCS object associated with
bbox
.- filterName
str
Name of the camera filter.
- epoch
astropy.time.Time
orNone
, optional Epoch to which to correct proper motion and parallax, or
None
to not apply such corrections.- bboxToSpherePadding
int
, optional Padding in pixels to account for translating a set of corners into a spherical (convex) boundary that is certain to encompass the enitre area covered by the box.
- bbox
- Returns:
- md
lsst.daf.base.PropertyList
The metadata detailing the search parameters used for this dataset.
- md
- static getMetadataCircle(coord, radius, filterName, epoch=None)¶
Return metadata about the reference catalog being loaded.
This metadata is used for reloading the catalog (e.g. for reconstituting a normalized match list).
- Parameters:
- coord
lsst.geom.SpherePoint
ICRS center of the search region.
- radius
lsst.geom.Angle
Radius of the search region.
- filterName
str
Name of the camera filter.
- epoch
astropy.time.Time
orNone
, optional Epoch to which to correct proper motion and parallax, or
None
to not apply such corrections.
- coord
- Returns:
- md
lsst.daf.base.PropertyList
Metadata about the catalog.
- md
- joinMatchListWithCatalog(matchCat, sourceCat)¶
Relink an unpersisted match list to sources and reference objects.
A match list is persisted and unpersisted as a catalog of IDs produced by afw.table.packMatches(), with match metadata (as returned by the astrometry tasks) in the catalog’s metadata attribute. This method converts such a match catalog into a match list, with links to source records and reference object records.
- Parameters:
- matchCat
lsst.afw.table.BaseCatalog
Unpersisted packed match list.
matchCat.table.getMetadata()
must contain match metadata, as returned by the astrometry tasks.- sourceCat
lsst.afw.table.SourceCatalog
Source catalog. As a side effect, the catalog will be sorted by ID.
- matchCat
- Returns:
- matchList
lsst.afw.table.ReferenceMatchVector
Match list.
- matchList
- static makeMinimalSchema(filterNameList, *, addCentroid=False, addIsPhotometric=False, addIsResolved=False, addIsVariable=False, coordErrDim=2, addProperMotion=False, properMotionErrDim=2, addParallax=False)¶
Make a standard schema for reference object catalogs.
- Parameters:
- filterNameList
list
ofstr
List of filter names. Used to create <filterName>_flux fields.
- addIsPhotometric
bool
If True then add field “photometric”.
- addIsResolved
bool
If True then add field “resolved”.
- addIsVariable
bool
If True then add field “variable”.
- coordErrDim
int
Number of coord error fields; must be one of 0, 2, 3:
If 2 or 3: add fields “coord_raErr” and “coord_decErr”.
If 3: also add field “coord_radecErr”.
- addProperMotion
bool
If True add fields “epoch”, “pm_ra”, “pm_dec” and “pm_flag”.
- properMotionErrDim
int
Number of proper motion error fields; must be one of 0, 2, 3; ignored if addProperMotion false: - If 2 or 3: add fields “pm_raErr” and “pm_decErr”. - If 3: also add field “pm_radecErr”.
- addParallax
bool
If True add fields “epoch”, “parallax”, “parallaxErr” and “parallax_flag”.
- filterNameList
- Returns:
- schema
lsst.afw.table.Schema
Schema for reference catalog, an
lsst.afw.table.SimpleCatalog
.
- schema
Notes
Reference catalogs support additional covariances, such as covariance between RA and proper motion in declination, that are not supported by this method, but can be added after calling this method.