LoadReferenceObjectsTask¶
Implementations must subclass this class, override the loadSkyCircle method, and will typically override the value of ConfigClass with a task-specific config class.
LoadReferenceObjectsTask
acts as an abstract base class for tasks that load objects from a reference catalog in a particluar region of sky.
Python API summary¶
from lsst.meas.algorithms.loadReferenceObjects import LoadReferenceObjectsTask
-
class
(butler=None, *args, **kwargs)LoadReferenceObjectsTask
Abstract base class to load objects from reference catalogs
...
-
attribute
config
Access configuration fields and retargetable subtasks.
See also
See the LoadReferenceObjectsTask
API reference for complete details.
Retargetable subtasks¶
No subtasks.
Configuration fields¶
anyFilterMapsToThis¶
Always use this reference catalog filter, no matter whether or what filter name is supplied to the loader. Effectively a trivial filterMap: map all filter names to this filter. This can be set for purely-astrometric catalogs (e.g. Gaia DR2) where there is only one reasonable choice for every camera filter->refcat mapping, but not for refcats used for photometry, which need a filterMap and/or colorterms/transmission corrections.
defaultFilter¶
Default reference catalog filter to use if filter not specified in exposure; if blank then filter must be specified in exposure. Deprecated: defaultFilter is deprecated by RFC-716. Will be removed after v22.
filterMap¶
Mapping of camera filter name: reference catalog filter name; each reference filter must exist in the refcat. Note that this does not perform any bandpass corrections: it is just a lookup.
pixelMargin¶
- Default
250
- Field type
int
RangeField
- Range
- [0,inf)
Padding to add to 4 all edges of the bounding box (pixels)
In Depth¶
Catalog Schema¶
coord
: ICRS position of star on sky (anlsst.geom.SpherePoint
)centroid
: position of star on an exposure, if relevant (anlsst.afw.Point2D
)hasCentroid
: is centroid usable? (a Flag)
<referenceFilterName>_flux
: brightness in the specified reference catalog filter (nJy)- Note: you can use astropy.units to convert from AB Magnitude to nJy:
u.Magnitude(value, u.ABmag).to_value(u.nJy)
<referenceFilterName>_fluxErr
(optional): brightness standard deviation (nJy); omitted if no data is available; possibly nan if data is available for some objects but not otherscamFlux
: brightness in default camera filter (nJy); omitted ifdefaultFilter
not specifiedcamFluxErr
: brightness standard deviation for default camera filter; omitted ifdefaultFilter
not specified or standard deviation not available that filter<cameraFilterName>_camFlux
: brightness in specified camera filter (nJy)
<cameraFilterName>_camFluxErr
(optional): brightness standard deviation in specified camera filter (nJy); omitted if no data is available;- possibly nan if data is available for some objects but not others
photometric
(optional): is the object usable for photometric calibration? (a Flag)resolved
(optional): is the object spatially resolved? (a Flag)variable
(optional): does the object have variable brightness? (a Flag)coord_raErr
: uncertainty incoord
along the direction of right ascension (radian, an Angle) = uncertainty in ra * cos(dec); nan if unknown
coord_decErr
: uncertainty incoord
along the direction of declination (radian, an Angle);- nan if unknown
- The following are optional; fields should only be present if the information is available for at least some objects.
Numeric values are
nan
if unknown:epoch
: date of observation as TAI MJD (day)pm_ra
: proper motion along the direction of right ascension (rad/year, an Angle) = dra/dt * cos(dec)pm_dec
: proper motion along the direction of declination (rad/year, and Angle)pm_raErr
: uncertainty inpm_ra
(rad/year)pm_decErr
: uncertainty inpm_dec
(rad/year)pm_ra_dec_Cov
: covariance between pm_ra and pm_dec (rad2/year2)pm_flag
: set if proper motion, error or covariance is badparallax
: parallax (rad, an Angle)parallaxErr
: uncertainty inparallax
(rad)parallax_flag
: set if parallax value or parallaxErr is badcoord_ra_pm_ra_Cov
: covariance between coord_ra and pm_ra (rad2/year)coord_ra_pm_dec_Cov
: covariance between coord_ra and pm_dec (rad2/year)coord_ra_parallax_Cov
: covariance between coord_ra and parallax (rad2/year)coord_dec_pm_ra_Cov
: covariance between coord_dec and pm_ra (rad2/year)coord_dec_pm_dec_Cov
: covariance between coord_dec and pm_dec (rad2/year)coord_dec_parallax_Cov
: covariance between coord_dec and parallax (rad2/year)pm_ra_parallax_Cov
: covariance between pm_ra and parallax (rad2/year)pm_dec_parallax_Cov
: covariance between pm_dec and parallax (rad2/year)