DirectMatchTask¶
DirectMatchTask
implements a brute force nearest neighbor match between
a input source catalog and a reference catalog.
The matching permits no rotation or scaling, but uses the existing sky positions in the source catalog. This is often useful for QA, as it allows validating the pipeline astrometry and photometry against the reference catalog.
Note that this DirectMatchTask is not currently suitable for use within the AstrometryTask, as it has a different interface and serves a different purpose.
Processing summary¶
DirectMatchTask
runs this sequence of operations:
- Finds an on sky circle covering the input source catalog.
- Loads reference objects within the circle.
- Performs a simple nearest neighbor assignment within a specified tolerance.
Python API summary¶
from lsst.meas.astrom.directMatch import DirectMatchTask
-
class
(butler=None, refObjLoader=None, **kwargs)DirectMatchTask
Simple, brute force matching of a source catalog to a reference catalog
...
-
attribute
config
Access configuration fields and retargetable subtasks.
See also
See the DirectMatchTask
API reference for complete details.
Retargetable subtasks¶
refObjLoader¶
- Default
lsst.meas.algorithms.loadIndexedReferenceObjects.LoadIndexedReferenceObjectsTask
- Field type
ConfigurableField
Load reference objects
referenceSelection¶
- Default
lsst.meas.algorithms.sourceSelector.ReferenceSourceSelectorTask
- Field type
ConfigurableField
Selection of reference sources
sourceSelection¶
- Default
lsst.meas.algorithms.sourceSelector.ScienceSourceSelectorTask
- Field type
ConfigurableField
Selection of science sources
Examples¶
config = DirectMatchConfig()
task = DirectMatchTask(butler=butler, config=config)
matchResults = task.run(catalog)