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1#
2# LSST Data Management System
3#
4# Copyright 2008-2017 AURA/LSST.
5#
6# This product includes software developed by the
7# LSST Project (http://www.lsst.org/).
8#
9# This program is free software: you can redistribute it and/or modify
10# it under the terms of the GNU General Public License as published by
11# the Free Software Foundation, either version 3 of the License, or
12# (at your option) any later version.
13#
14# This program is distributed in the hope that it will be useful,
15# but WITHOUT ANY WARRANTY; without even the implied warranty of
16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17# GNU General Public License for more details.
18#
19# You should have received a copy of the LSST License Statement and
20# the GNU General Public License along with this program. If not,
21# see <https://www.lsstcorp.org/LegalNotices/>.
22#
24__all__ = ["getRefFluxField", "getRefFluxKeys", "LoadReferenceObjectsTask", "LoadReferenceObjectsConfig",
25 "ReferenceObjectLoader"]
27import abc
28import itertools
30import astropy.time
31import astropy.units
32import numpy
34import lsst.geom
35import lsst.afw.table as afwTable
36import lsst.pex.config as pexConfig
37import lsst.pex.exceptions as pexExceptions
38import lsst.pipe.base as pipeBase
39import lsst.pex.exceptions as pexExcept
40import lsst.log
41from lsst import geom
42from lsst import sphgeom
43from lsst.daf.base import PropertyList
46def isOldFluxField(name, units):
47 """Return True if this name/units combination corresponds to an
48 "old-style" reference catalog flux field.
49 """
50 unitsCheck = units != 'nJy' # (units == 'Jy' or units == '' or units == '?')
51 isFlux = name.endswith('_flux')
52 isFluxSigma = name.endswith('_fluxSigma')
53 isFluxErr = name.endswith('_fluxErr')
54 return (isFlux or isFluxSigma or isFluxErr) and unitsCheck
57def hasNanojanskyFluxUnits(schema):
58 """Return True if the units of all flux and fluxErr are correct (nJy).
59 """
60 for field in schema:
61 if isOldFluxField(field.field.getName(), field.field.getUnits()):
62 return False
63 return True
66def getFormatVersionFromRefCat(refCat):
67 """"Return the format version stored in a reference catalog header.
69 Parameters
70 ----------
71 refCat : `lsst.afw.table.SimpleCatalog`
72 Reference catalog to inspect.
74 Returns
75 -------
76 version : `int` or `None`
77 Format version integer, or `None` if the catalog has no metadata
78 or the metadata does not include a "REFCAT_FORMAT_VERSION" key.
79 """
80 md = refCat.getMetadata()
81 if md is None:
82 return None
83 try:
84 return md.getScalar("REFCAT_FORMAT_VERSION")
85 except KeyError:
86 return None
89def convertToNanojansky(catalog, log, doConvert=True):
90 """Convert fluxes in a catalog from jansky to nanojansky.
92 Parameters
93 ----------
94 catalog : `lsst.afw.table.SimpleCatalog`
95 The catalog to convert.
96 log : `lsst.log.Log`
97 Log to send messages to.
98 doConvert : `bool`, optional
99 Return a converted catalog, or just identify the fields that need to be converted?
100 This supports the "write=False" mode of `bin/convert_to_nJy.py`.
102 Returns
103 -------
104 catalog : `lsst.afw.table.SimpleCatalog` or None
105 The converted catalog, or None if ``doConvert`` is False.
107 Notes
108 -----
109 Support for old units in reference catalogs will be removed after the
110 release of late calendar year 2019.
111 Use `meas_algorithms/bin/convert_to_nJy.py` to update your reference catalog.
112 """
113 # Do not share the AliasMap: for refcats, that gets created when the
114 # catalog is read from disk and should not be propagated.
115 mapper = lsst.afw.table.SchemaMapper(catalog.schema, shareAliasMap=False)
116 mapper.addMinimalSchema(lsst.afw.table.SimpleTable.makeMinimalSchema())
117 input_fields = []
118 output_fields = []
119 for field in catalog.schema:
120 oldName = field.field.getName()
121 oldUnits = field.field.getUnits()
122 if isOldFluxField(oldName, oldUnits):
123 units = 'nJy'
124 # remap Sigma flux fields to Err, so we can drop the alias
125 if oldName.endswith('_fluxSigma'):
126 name = oldName.replace('_fluxSigma', '_fluxErr')
127 else:
128 name = oldName
129 newField = lsst.afw.table.Field[field.dtype](name, field.field.getDoc(), units)
130 mapper.addMapping(field.getKey(), newField)
131 input_fields.append(field.field)
132 output_fields.append(newField)
133 else:
134 mapper.addMapping(field.getKey())
136 fluxFieldsStr = '; '.join("(%s, '%s')" % (field.getName(), field.getUnits()) for field in input_fields)
138 if doConvert:
139 newSchema = mapper.getOutputSchema()
140 output = lsst.afw.table.SimpleCatalog(newSchema)
141 output.extend(catalog, mapper=mapper)
142 for field in output_fields:
143 output[field.getName()] *= 1e9
144 log.info(f"Converted refcat flux fields to nJy (name, units): {fluxFieldsStr}")
145 return output
146 else:
147 log.info(f"Found old-style refcat flux fields (name, units): {fluxFieldsStr}")
148 return None
151class _FilterCatalog:
152 """This is a private helper class which filters catalogs by
153 row based on the row being inside the region used to initialize
154 the class.
156 Parameters
157 ----------
158 region : `lsst.sphgeom.Region`
159 The spatial region which all objects should lie within
160 """
161 def __init__(self, region):
162 self.region = region
164 def __call__(self, refCat, catRegion):
165 """This call method on an instance of this class takes in a reference
166 catalog, and the region from which the catalog was generated.
168 If the catalog region is entirely contained within the region used to
169 initialize this class, then all the entries in the catalog must be
170 within the region and so the whole catalog is returned.
172 If the catalog region is not entirely contained, then the location for
173 each record is tested against the region used to initialize the class.
174 Records which fall inside this region are added to a new catalog, and
175 this catalog is then returned.
177 Parameters
178 ---------
179 refCat : `lsst.afw.table.SourceCatalog`
180 SourceCatalog to be filtered.
181 catRegion : `lsst.sphgeom.Region`
182 Region in which the catalog was created
183 """
184 if catRegion.isWithin(self.region):
185 # no filtering needed, region completely contains refcat
186 return refCat
188 filteredRefCat = type(refCat)(refCat.table)
189 for record in refCat:
190 if self.region.contains(record.getCoord().getVector()):
191 filteredRefCat.append(record)
192 return filteredRefCat
195class ReferenceObjectLoader:
196 """ This class facilitates loading reference catalogs with gen 3 middleware
198 The middleware preflight solver will create a list of datarefs that may
199 possibly overlap a given region. These datarefs are then used to construct
200 and instance of this class. The class instance should then be passed into
201 a task which needs reference catalogs. These tasks should then determine
202 the exact region of the sky reference catalogs will be loaded for, and
203 call a corresponding method to load the reference objects.
204 """
205 def __init__(self, dataIds, refCats, config, log=None):
206 """ Constructs an instance of ReferenceObjectLoader
208 Parameters
209 ----------
210 dataIds : iterable of `lsst.daf.butler.DataIds`
211 An iterable object of DataSetRefs which point to reference catalogs
212 in a gen 3 repository
213 refCats : Iterable of `lsst.daf.butler.DeferedDatasetHandle`
214 Handles to load refCats on demand
215 log : `lsst.log.Log`
216 Logger object used to write out messages. If `None` (default) the default
217 lsst logger will be used
219 """
220 self.dataIds = dataIds
221 self.refCats = refCats
222 self.log = log or lsst.log.Log.getDefaultLogger()
223 self.config = config
225 @staticmethod
226 def _makeBoxRegion(BBox, wcs, BBoxPadding):
227 outerLocalBBox = geom.Box2D(BBox)
228 innerLocalBBox = geom.Box2D(BBox)
230 # Grow the bounding box to make sure the spherical geometry bbox will contain
231 # the same region, as non-padded boxes may contain different regions because of optical distortion.
232 # Also create an inner region that is sure to be inside the bbox
233 outerLocalBBox.grow(BBoxPadding)
234 innerLocalBBox.grow(-1*BBoxPadding)
236 # Handle the fact that the inner bounding box shrunk to a zero sized region in at least one
237 # dimension, in which case all reference catalogs must be checked fully against the input
238 # bounding box
239 if innerLocalBBox.getDimensions() == geom.Extent2D(0, 0):
240 innerSkyRegion = sphgeom.Box()
241 else:
242 innerBoxCorners = innerLocalBBox.getCorners()
243 innerSphCorners = [wcs.pixelToSky(corner).getVector() for corner in innerBoxCorners]
245 innerSkyRegion = sphgeom.ConvexPolygon(innerSphCorners)
247 # Convert the corners of the box to sky coordinates
248 outerBoxCorners = outerLocalBBox.getCorners()
249 outerSphCorners = [wcs.pixelToSky(corner).getVector() for corner in outerBoxCorners]
251 outerSkyRegion = sphgeom.ConvexPolygon(outerSphCorners)
253 return innerSkyRegion, outerSkyRegion, innerSphCorners, outerSphCorners
255 def loadPixelBox(self, bbox, wcs, filterName=None, epoch=None, photoCalib=None, bboxPadding=100):
256 """Load reference objects that are within a pixel-based rectangular region
258 This algorithm works by creating a spherical box whose corners correspond
259 to the WCS converted corners of the input bounding box (possibly padded).
260 It then defines a filtering function which will look at a reference
261 objects pixel position and accept objects that lie within the specified
262 bounding box.
264 The spherical box region and filtering function are passed to the generic
265 loadRegion method which will load and filter the reference objects from
266 the datastore and return a single catalog containing all reference objects
268 Parameters
269 ----------
270 bbox : `lsst.geom.box2I`
271 Box which bounds a region in pixel space
272 wcs : `lsst.afw.geom.SkyWcs`
273 Wcs object defining the pixel to sky (and inverse) transform for the space
274 of pixels of the supplied bbox
275 filterName : `str`
276 Name of camera filter, or None or blank for the default filter
277 epoch : `astropy.time.Time` (optional)
278 Epoch to which to correct proper motion and parallax,
279 or None to not apply such corrections.
280 photoCalib : None
281 Deprecated and ignored, only included for api compatibility
282 bboxPadding : `int`
283 Number describing how much to pad the input bbox by (in pixels), defaults
284 to 100. This parameter is necessary because optical distortions in telescopes
285 can cause a rectangular pixel grid to map into a non "rectangular" spherical
286 region in sky coordinates. This padding is used to create a spherical
287 "rectangle", which will for sure enclose the input box. This padding is only
288 used to determine if the reference catalog for a sky patch will be loaded from
289 the data store, this function will filter out objects which lie within the
290 padded region but fall outside the input bounding box region.
292 Returns
293 -------
294 referenceCatalog : `lsst.afw.table.SimpleCatalog`
295 Catalog containing reference objects inside the specified bounding box
297 Raises
298 ------
299 `lsst.pex.exception.RuntimeError`
300 Raised if no reference catalogs could be found for the specified region
302 `lsst.pex.exception.TypeError`
303 Raised if the loaded reference catalogs do not have matching schemas
304 """
305 innerSkyRegion, outerSkyRegion, _, _ = self._makeBoxRegion(bbox, wcs, bboxPadding)
307 def _filterFunction(refCat, region):
308 # Add columns to the reference catalog relating to center positions and use afwTable
309 # to populate those columns
310 refCat = self.remapReferenceCatalogSchema(refCat, position=True)
311 afwTable.updateRefCentroids(wcs, refCat)
312 # no need to filter the catalog if it is sure that it is entirely contained in the region
313 # defined by given bbox
314 if innerSkyRegion.contains(region):
315 return refCat
316 # Create a new reference catalog, and populate it with records which fall inside the bbox
317 filteredRefCat = type(refCat)(refCat.table)
318 centroidKey = afwTable.Point2DKey(refCat.schema['centroid'])
319 for record in refCat:
320 pixCoords = record[centroidKey]
321 if bbox.contains(geom.Point2I(pixCoords)):
322 filteredRefCat.append(record)
323 return filteredRefCat
324 return self.loadRegion(outerSkyRegion, filtFunc=_filterFunction, epoch=epoch, filterName=filterName)
326 def loadRegion(self, region, filtFunc=None, filterName=None, epoch=None):
327 """ Load reference objects within a specified region
329 This function loads the DataIds used to construct an instance of this class
330 which intersect or are contained within the specified region. The reference
331 catalogs which intersect but are not fully contained within the input region are
332 further filtered by the specified filter function. This function will return a
333 single source catalog containing all reference objects inside the specified region.
335 Parameters
336 ----------
337 region : `lsst.sphgeom.Region`
338 This can be any type that is derived from `lsst.sphgeom.region` and should
339 define the spatial region for which reference objects are to be loaded.
340 filtFunc : callable
341 This optional parameter should be a callable object that takes a reference
342 catalog and its corresponding region as parameters, filters the catalog by
343 some criteria and returns the filtered reference catalog. If the value is
344 left as the default (None) than an internal filter function is used which
345 filters according to if a reference object falls within the input region.
346 filterName : `str`
347 Name of camera filter, or None or blank for the default filter
348 epoch : `astropy.time.Time` (optional)
349 Epoch to which to correct proper motion and parallax,
350 or None to not apply such corrections.
352 Returns
353 -------
354 referenceCatalog : `lsst.afw.table.SourceCatalog`
355 Catalog containing reference objects which intersect the input region,
356 filtered by the specified filter function
358 Raises
359 ------
360 `lsst.pex.exception.RuntimeError`
361 Raised if no reference catalogs could be found for the specified region
363 `lsst.pex.exception.TypeError`
364 Raised if the loaded reference catalogs do not have matching schemas
366 """
367 regionBounding = region.getBoundingBox()
368 self.log.info("Loading reference objects from region bounded by {}, {} lat lon".format(
369 regionBounding.getLat(), regionBounding.getLon()))
370 if filtFunc is None:
371 filtFunc = _FilterCatalog(region)
372 # filter out all the regions supplied by the constructor that do not overlap
373 overlapList = []
374 for dataId, refCat in zip(self.dataIds, self.refCats):
375 # SphGeom supports some objects intersecting others, but is not symmetric,
376 # try the intersect operation in both directions
377 try:
378 intersects = dataId.region.intersects(region)
379 except TypeError:
380 intersects = region.intersects(dataId.region)
382 if intersects:
383 overlapList.append((dataId, refCat))
385 if len(overlapList) == 0:
386 raise pexExceptions.RuntimeError("No reference tables could be found for input region")
388 firstCat = overlapList[0][1].get()
389 refCat = filtFunc(firstCat, overlapList[0][0].region)
390 trimmedAmount = len(firstCat) - len(refCat)
392 # Load in the remaining catalogs
393 for dataId, inputRefCat in overlapList[1:]:
394 tmpCat = inputRefCat.get()
396 if tmpCat.schema != firstCat.schema:
397 raise pexExceptions.TypeError("Reference catalogs have mismatching schemas")
399 filteredCat = filtFunc(tmpCat, dataId.region)
400 refCat.extend(filteredCat)
401 trimmedAmount += len(tmpCat) - len(filteredCat)
403 self.log.debug(f"Trimmed {trimmedAmount} out of region objects, leaving {len(refCat)}")
404 self.log.info(f"Loaded {len(refCat)} reference objects")
406 # Ensure that the loaded reference catalog is continuous in memory
407 if not refCat.isContiguous():
408 refCat = refCat.copy(deep=True)
410 if epoch is not None and "pm_ra" in refCat.schema:
411 # check for a catalog in a non-standard format
412 if isinstance(refCat.schema["pm_ra"].asKey(), lsst.afw.table.KeyAngle):
413 applyProperMotionsImpl(self.log, refCat, epoch)
414 else:
415 self.log.warn("Catalog pm_ra field is not an Angle; not applying proper motion")
417 # Verify the schema is in the correct units and has the correct version; automatically convert
418 # it with a warning if this is not the case.
419 if not hasNanojanskyFluxUnits(refCat.schema) or not getFormatVersionFromRefCat(refCat) >= 1:
420 self.log.warn("Found version 0 reference catalog with old style units in schema.")
421 self.log.warn("run `meas_algorithms/bin/convert_refcat_to_nJy.py` to convert fluxes to nJy.")
422 self.log.warn("See RFC-575 for more details.")
423 refCat = convertToNanojansky(refCat, self.log)
425 expandedCat = self.remapReferenceCatalogSchema(refCat, position=True)
427 # Add flux aliases
428 expandedCat = self.addFluxAliases(expandedCat, self.config.defaultFilter, self.config.filterMap)
430 # Ensure that the returned reference catalog is continuous in memory
431 if not expandedCat.isContiguous():
432 expandedCat = expandedCat.copy(deep=True)
434 fluxField = getRefFluxField(schema=expandedCat.schema, filterName=filterName)
435 return pipeBase.Struct(refCat=expandedCat, fluxField=fluxField)
437 def loadSkyCircle(self, ctrCoord, radius, filterName=None, epoch=None):
438 """Load reference objects that lie within a circular region on the sky
440 This method constructs a circular region from an input center and angular radius,
441 loads reference catalogs which are contained in or intersect the circle, and
442 filters reference catalogs which intersect down to objects which lie within
443 the defined circle.
445 Parameters
446 ----------
447 ctrCoord : `lsst.geom.SpherePoint`
448 Point defining the center of the circular region
449 radius : `lsst.geom.Angle`
450 Defines the angular radius of the circular region
451 filterName : `str`
452 Name of camera filter, or None or blank for the default filter
453 epoch : `astropy.time.Time` (optional)
454 Epoch to which to correct proper motion and parallax,
455 or None to not apply such corrections.
457 Returns
458 -------
459 referenceCatalog : `lsst.afw.table.SourceCatalog`
460 Catalog containing reference objects inside the specified bounding box
462 Raises
463 ------
464 `lsst.pex.exception.RuntimeError`
465 Raised if no reference catalogs could be found for the specified region
467 `lsst.pex.exception.TypeError`
468 Raised if the loaded reference catalogs do not have matching schemas
470 """
471 centerVector = ctrCoord.getVector()
472 sphRadius = sphgeom.Angle(radius.asRadians())
473 circularRegion = sphgeom.Circle(centerVector, sphRadius)
474 return self.loadRegion(circularRegion, filterName=filterName, epoch=epoch)
476 def joinMatchListWithCatalog(self, matchCat, sourceCat):
477 """Relink an unpersisted match list to sources and reference
478 objects.
480 A match list is persisted and unpersisted as a catalog of IDs
481 produced by afw.table.packMatches(), with match metadata
482 (as returned by the astrometry tasks) in the catalog's metadata
483 attribute. This method converts such a match catalog into a match
484 list, with links to source records and reference object records.
486 Parameters
487 ----------
488 matchCat : `lsst.afw.table.BaseCatalog`
489 Unpersisted packed match list.
490 ``matchCat.table.getMetadata()`` must contain match metadata,
491 as returned by the astrometry tasks.
492 sourceCat : `lsst.afw.table.SourceCatalog`
493 Source catalog. As a side effect, the catalog will be sorted
494 by ID.
496 Returns
497 -------
498 matchList : `lsst.afw.table.ReferenceMatchVector`
499 Match list.
500 """
501 return joinMatchListWithCatalogImpl(self, matchCat, sourceCat)
503 @classmethod
504 def getMetadataBox(cls, bbox, wcs, filterName=None, photoCalib=None, epoch=None, bboxPadding=100):
505 """Return metadata about the load
507 This metadata is used for reloading the catalog (e.g., for
508 reconstituting a normalised match list.)
510 Parameters
511 ----------
512 bbox : `lsst.geom.Box2I`
513 Bounding bos for the pixels
514 wcs : `lsst.afw.geom.SkyWcs
515 WCS object
516 filterName : `str` or None
517 filterName of the camera filter, or None or blank for the default filter
518 photoCalib : None
519 Deprecated, only included for api compatibility
520 epoch : `astropy.time.Time` (optional)
521 Epoch to which to correct proper motion and parallax,
522 or None to not apply such corrections.
523 bboxPadding : `int`
524 Number describing how much to pad the input bbox by (in pixels), defaults
525 to 100. This parameter is necessary because optical distortions in telescopes
526 can cause a rectangular pixel grid to map into a non "rectangular" spherical
527 region in sky coordinates. This padding is used to create a spherical
528 "rectangle", which will for sure enclose the input box. This padding is only
529 used to determine if the reference catalog for a sky patch will be loaded from
530 the data store, this function will filter out objects which lie within the
531 padded region but fall outside the input bounding box region.
532 Returns
533 -------
534 md : `lsst.daf.base.PropertyList`
535 """
536 _, _, innerCorners, outerCorners = cls._makeBoxRegion(bbox, wcs, bboxPadding)
537 md = PropertyList()
538 for box, corners in zip(("INNER", "OUTER"), (innerCorners, outerCorners)):
539 for (name, corner) in zip(("UPPER_LEFT", "UPPER_RIGHT", "LOWER_LEFT", "LOWER_RIGHT"),
540 corners):
541 md.add(f"{box}_{name}_RA", geom.SpherePoint(corner).getRa().asDegrees(), f"{box}_corner")
542 md.add(f"{box}_{name}_DEC", geom.SpherePoint(corner).getDec().asDegrees(), f"{box}_corner")
543 md.add("SMATCHV", 1, 'SourceMatchVector version number')
544 filterName = "UNKNOWN" if filterName is None else str(filterName)
545 md.add('FILTER', filterName, 'filter name for photometric data')
546 md.add('EPOCH', "NONE" if epoch is None else epoch.mjd, 'Epoch (TAI MJD) for catalog')
547 return md
549 @staticmethod
550 def getMetadataCircle(coord, radius, filterName, photoCalib=None, epoch=None):
551 """Return metadata about the load
553 This metadata is used for reloading the catalog (e.g. for reconstituting
554 a normalized match list.)
556 Parameters
557 ----------
558 coord : `lsst.geom.SpherePoint`
559 ICRS center of a circle
560 radius : `lsst.geom.angle`
561 radius of a circle
562 filterName : `str` or None
563 filterName of the camera filter, or None or blank for the default filter
564 photoCalib : None
565 Deprecated, only included for api compatibility
566 epoch : `astropy.time.Time` (optional)
567 Epoch to which to correct proper motion and parallax,
568 or None to not apply such corrections.
570 Returns
571 -------
572 md : `lsst.daf.base.PropertyList`
573 """
574 md = PropertyList()
575 md.add('RA', coord.getRa().asDegrees(), 'field center in degrees')
576 md.add('DEC', coord.getDec().asDegrees(), 'field center in degrees')
577 md.add('RADIUS', radius.asDegrees(), 'field radius in degrees, minimum')
578 md.add('SMATCHV', 1, 'SourceMatchVector version number')
579 filterName = "UNKNOWN" if filterName is None else str(filterName)
580 md.add('FILTER', filterName, 'filter name for photometric data')
581 md.add('EPOCH', "NONE" if epoch is None else epoch.mjd, 'Epoch (TAI MJD) for catalog')
582 return md
584 @staticmethod
585 def addFluxAliases(refCat, defaultFilter, filterReferenceMap):
586 """This function creates a new catalog containing the information of the input refCat
587 as well as added flux columns and aliases between camera and reference flux.
589 Parameters
590 ----------
591 refCat : `lsst.afw.table.SimpleCatalog`
592 Catalog of reference objects
593 defaultFilter : `str`
594 Name of the default reference filter
595 filterReferenceMap : `dict` of `str`
596 Dictionary with keys corresponding to a filter name, and values which
597 correspond to the name of the reference filter.
599 Returns
600 -------
601 refCat : `lsst.afw.table.SimpleCatalog`
602 Reference catalog with columns added to track reference filters
604 Raises
605 ------
606 `RuntimeError`
607 If specified reference filter name is not a filter specifed as a key in the
608 reference filter map.
609 """
610 refCat = ReferenceObjectLoader.remapReferenceCatalogSchema(refCat,
611 filterNameList=filterReferenceMap.keys())
612 aliasMap = refCat.schema.getAliasMap()
613 if filterReferenceMap is None:
614 filterReferenceMap = {}
615 for filterName, refFilterName in itertools.chain([(None, defaultFilter)],
616 filterReferenceMap.items()):
617 if refFilterName:
618 camFluxName = filterName + "_camFlux" if filterName is not None else "camFlux"
619 refFluxName = refFilterName + "_flux"
620 if refFluxName not in refCat.schema:
621 raise RuntimeError("Unknown reference filter %s" % (refFluxName,))
622 aliasMap.set(camFluxName, refFluxName)
624 refFluxErrName = refFluxName + "Err"
625 camFluxErrName = camFluxName + "Err"
626 aliasMap.set(camFluxErrName, refFluxErrName)
628 return refCat
630 @staticmethod
631 def remapReferenceCatalogSchema(refCat, *, filterNameList=None, position=False, photometric=False):
632 """This function takes in a reference catalog and creates a new catalog with additional
633 columns defined the remaining function arguments.
635 Parameters
636 ----------
637 refCat : `lsst.afw.table.SimpleCatalog`
638 Reference catalog to map to new catalog
640 Returns
641 -------
642 expandedCat : `lsst.afw.table.SimpleCatalog`
643 Deep copy of input reference catalog with additional columns added
644 """
645 mapper = afwTable.SchemaMapper(refCat.schema, True)
646 mapper.addMinimalSchema(refCat.schema, True)
647 mapper.editOutputSchema().disconnectAliases()
648 if filterNameList:
649 for filterName in filterNameList:
650 mapper.editOutputSchema().addField(f"{filterName}_flux",
651 type=numpy.float64,
652 doc=f"flux in filter {filterName}",
653 units="Jy"
654 )
655 mapper.editOutputSchema().addField(f"{filterName}_fluxErr",
656 type=numpy.float64,
657 doc=f"flux uncertanty in filter {filterName}",
658 units="Jy"
659 )
661 if position:
662 mapper.editOutputSchema().addField("centroid_x", type=float, doReplace=True)
663 mapper.editOutputSchema().addField("centroid_y", type=float, doReplace=True)
664 mapper.editOutputSchema().addField("hasCentroid", type="Flag", doReplace=True)
665 mapper.editOutputSchema().getAliasMap().set("slot_Centroid", "centroid")
667 if photometric:
668 mapper.editOutputSchema().addField("photometric",
669 type="Flag",
670 doc="set if the object can be used for photometric"
671 "calibration",
672 )
673 mapper.editOutputSchema().addField("resolved",
674 type="Flag",
675 doc="set if the object is spatially resolved"
676 )
677 mapper.editOutputSchema().addField("variable",
678 type="Flag",
679 doc="set if the object has variable brightness"
680 )
682 expandedCat = afwTable.SimpleCatalog(mapper.getOutputSchema())
683 expandedCat.setMetadata(refCat.getMetadata())
684 expandedCat.extend(refCat, mapper=mapper)
686 return expandedCat
689def getRefFluxField(schema, filterName=None):
690 """Get the name of a flux field from a schema.
692 return the alias of "anyFilterMapsToThis", if present
693 else if filterName is specified:
694 return "*filterName*_camFlux" if present
695 else return "*filterName*_flux" if present (camera filter name
696 matches reference filter name)
697 else throw RuntimeError
698 else:
699 return "camFlux", if present,
700 else throw RuntimeError
702 Parameters
703 ----------
704 schema : `lsst.afw.table.Schema`
705 Reference catalog schema.
706 filterName : `str`, optional
707 Name of camera filter. If not specified, ``defaultFilter`` needs to be
708 set in the refcat loader config.
710 Returns
711 -------
712 fluxFieldName : `str`
713 Name of flux field.
715 Raises
716 ------
717 RuntimeError
718 If an appropriate field is not found.
719 """
720 if not isinstance(schema, afwTable.Schema):
721 raise RuntimeError("schema=%s is not a schema" % (schema,))
722 try:
723 return schema.getAliasMap().get("anyFilterMapsToThis")
724 except LookupError:
725 pass # try the filterMap next
727 if filterName:
728 fluxFieldList = [filterName + "_camFlux", filterName + "_flux"]
729 else:
730 fluxFieldList = ["camFlux"]
731 for fluxField in fluxFieldList:
732 if fluxField in schema:
733 return fluxField
735 raise RuntimeError("Could not find flux field(s) %s" % (", ".join(fluxFieldList)))
738def getRefFluxKeys(schema, filterName=None):
739 """Return keys for flux and flux error.
741 Parameters
742 ----------
743 schema : `lsst.afw.table.Schema`
744 Reference catalog schema.
745 filterName : `str`
746 Name of camera filter.
748 Returns
749 -------
750 keys : `tuple` of (`lsst.afw.table.Key`, `lsst.afw.table.Key`)
751 Two keys:
753 - flux key
754 - flux error key, if present, else None
756 Raises
757 ------
758 RuntimeError
759 If flux field not found.
760 """
761 fluxField = getRefFluxField(schema, filterName)
762 fluxErrField = fluxField + "Err"
763 fluxKey = schema[fluxField].asKey()
764 try:
765 fluxErrKey = schema[fluxErrField].asKey()
766 except Exception:
767 fluxErrKey = None
768 return (fluxKey, fluxErrKey)
771class LoadReferenceObjectsConfig(pexConfig.Config):
772 pixelMargin = pexConfig.RangeField(
773 doc="Padding to add to 4 all edges of the bounding box (pixels)",
774 dtype=int,
775 default=300,
776 min=0,
777 )
778 defaultFilter = pexConfig.Field(
779 doc=("Default reference catalog filter to use if filter not specified in exposure;"
780 " if blank then filter must be specified in exposure."),
781 dtype=str,
782 default="",
783 )
784 anyFilterMapsToThis = pexConfig.Field(
785 doc=("Always use this reference catalog filter, no matter whether or what filter name is "
786 "supplied to the loader. Effectively a trivial filterMap: map all filter names to this filter."
787 " This can be set for purely-astrometric catalogs (e.g. Gaia DR2) where there is only one "
788 "reasonable choice for every camera filter->refcat mapping, but not for refcats used for "
789 "photometry, which need a filterMap and/or colorterms/transmission corrections."),
790 dtype=str,
791 default=None,
792 optional=True
793 )
794 filterMap = pexConfig.DictField(
795 doc=("Mapping of camera filter name: reference catalog filter name; "
796 "each reference filter must exist in the refcat."
797 " Note that this does not perform any bandpass corrections: it is just a lookup."),
798 keytype=str,
799 itemtype=str,
800 default={},
801 )
802 requireProperMotion = pexConfig.Field(
803 doc="Require that the fields needed to correct proper motion "
804 "(epoch, pm_ra and pm_dec) are present?",
805 dtype=bool,
806 default=False,
807 )
809 def validate(self):
810 super().validate()
811 if self.filterMap != {} and self.anyFilterMapsToThis is not None:
812 msg = "`filterMap` and `anyFilterMapsToThis` are mutually exclusive"
813 raise pexConfig.FieldValidationError(LoadReferenceObjectsConfig.anyFilterMapsToThis,
814 self, msg)
817# The following comment block adds a link to this task from the Task Documentation page.
818## @addtogroup LSST_task_documentation
819## @{
820## @page LoadReferenceObjectsTask
821## @ref LoadReferenceObjectsTask_ "LoadReferenceObjectsTask"
822## @copybrief LoadReferenceObjectsTask
823## @}
826class LoadReferenceObjectsTask(pipeBase.Task, metaclass=abc.ABCMeta):
827 r"""!Abstract base class to load objects from reference catalogs
829 @anchor LoadReferenceObjectsTask_
831 @section meas_algorithms_loadReferenceObjects_Contents Contents
833 - @ref meas_algorithms_loadReferenceObjects_Purpose
834 - @ref meas_algorithms_loadReferenceObjects_Initialize
835 - @ref meas_algorithms_loadReferenceObjects_IO
836 - @ref meas_algorithms_loadReferenceObjects_Schema
837 - @ref meas_algorithms_loadReferenceObjects_Config
839 @section meas_algorithms_loadReferenceObjects_Purpose Description
841 Abstract base class for tasks that load objects from a reference catalog
842 in a particular region of the sky.
844 Implementations must subclass this class, override the loadSkyCircle method,
845 and will typically override the value of ConfigClass with a task-specific config class.
847 @section meas_algorithms_loadReferenceObjects_Initialize Task initialisation
849 @copydoc \_\_init\_\_
851 @section meas_algorithms_loadReferenceObjects_IO Invoking the Task
853 @copydoc loadPixelBox
855 @section meas_algorithms_loadReferenceObjects_Schema Schema of the reference object catalog
857 Reference object catalogs are instances of lsst.afw.table.SimpleCatalog with the following schema
858 (other fields may also be present).
859 The units use astropy quantity conventions, so a 2 suffix means squared.
860 See also makeMinimalSchema.
861 - coord: ICRS position of star on sky (an lsst.geom.SpherePoint)
862 - centroid: position of star on an exposure, if relevant (an lsst.afw.Point2D)
863 - hasCentroid: is centroid usable? (a Flag)
864 - *referenceFilterName*_flux: brightness in the specified reference catalog filter (nJy)
865 Note: you can use astropy.units to convert from AB Magnitude to nJy:
866 `u.Magnitude(value, u.ABmag).to_value(u.nJy)`
867 - *referenceFilterName*_fluxErr (optional): brightness standard deviation (nJy);
868 omitted if no data is available; possibly nan if data is available for some objects but not others
869 - camFlux: brightness in default camera filter (nJy); omitted if defaultFilter not specified
870 - camFluxErr: brightness standard deviation for default camera filter;
871 omitted if defaultFilter not specified or standard deviation not available that filter
872 - *cameraFilterName*_camFlux: brightness in specified camera filter (nJy)
873 - *cameraFilterName*_camFluxErr (optional): brightness standard deviation
874 in specified camera filter (nJy); omitted if no data is available;
875 possibly nan if data is available for some objects but not others
876 - photometric (optional): is the object usable for photometric calibration? (a Flag)
877 - resolved (optional): is the object spatially resolved? (a Flag)
878 - variable (optional): does the object have variable brightness? (a Flag)
879 - coord_raErr: uncertainty in `coord` along the direction of right ascension (radian, an Angle)
880 = uncertainty in ra * cos(dec); nan if unknown
881 - coord_decErr: uncertainty in `coord` along the direction of declination (radian, an Angle);
882 nan if unknown
884 The following are optional; fields should only be present if the
885 information is available for at least some objects.
886 Numeric values are `nan` if unknown:
887 - epoch: date of observation as TAI MJD (day)
889 - pm_ra: proper motion along the direction of right ascension (rad/year, an Angle) = dra/dt * cos(dec)
890 - pm_dec: proper motion along the direction of declination (rad/year, and Angle)
891 - pm_raErr: uncertainty in `pm_ra` (rad/year)
892 - pm_decErr: uncertainty in `pm_dec` (rad/year)
893 - pm_ra_dec_Cov: covariance between pm_ra and pm_dec (rad2/year2)
894 - pm_flag: set if proper motion, error or covariance is bad
896 - parallax: parallax (rad, an Angle)
897 - parallaxErr: uncertainty in `parallax` (rad)
898 - parallax_flag: set if parallax value or parallaxErr is bad
900 - coord_ra_pm_ra_Cov: covariance between coord_ra and pm_ra (rad2/year)
901 - coord_ra_pm_dec_Cov: covariance between coord_ra and pm_dec (rad2/year)
902 - coord_ra_parallax_Cov: covariance between coord_ra and parallax (rad2/year)
903 - coord_dec_pm_ra_Cov: covariance between coord_dec and pm_ra (rad2/year)
904 - coord_dec_pm_dec_Cov: covariance between coord_dec and pm_dec (rad2/year)
905 - coord_dec_parallax_Cov: covariance between coord_dec and parallax (rad2/year)
906 - pm_ra_parallax_Cov: covariance between pm_ra and parallax (rad2/year)
907 - pm_dec_parallax_Cov: covariance between pm_dec and parallax (rad2/year)
909 @section meas_algorithms_loadReferenceObjects_Config Configuration parameters
911 See @ref LoadReferenceObjectsConfig for a base set of configuration parameters.
912 Most subclasses will add configuration variables.
913 """
914 ConfigClass = LoadReferenceObjectsConfig
915 _DefaultName = "LoadReferenceObjects"
917 def __init__(self, butler=None, *args, **kwargs):
918 """Construct a LoadReferenceObjectsTask
920 Parameters
921 ----------
922 butler : `lsst.daf.persistence.Butler`
923 Data butler, for access reference catalogs.
924 """
925 pipeBase.Task.__init__(self, *args, **kwargs)
926 self.butler = butler
928 @pipeBase.timeMethod
929 def loadPixelBox(self, bbox, wcs, filterName=None, photoCalib=None, epoch=None):
930 """Load reference objects that overlap a rectangular pixel region.
932 Parameters
933 ----------
934 bbox : `lsst.geom.Box2I` or `lsst.geom.Box2D`
935 Bounding box for pixels.
936 wcs : `lsst.afw.geom.SkyWcs`
937 WCS; used to convert pixel positions to sky coordinates
938 and vice-versa.
939 filterName : `str`
940 Name of filter, or `None` or `""` for the default filter.
941 This is used for flux values in case we have flux limits
942 (which are not yet implemented).
943 photoCalib : `lsst.afw.image.PhotoCalib` (optional)
944 Calibration, or `None` if unknown.
945 epoch : `astropy.time.Time` (optional)
946 Epoch to which to correct proper motion and parallax,
947 or None to not apply such corrections.
949 Returns
950 -------
951 results : `lsst.pipe.base.Struct`
952 A Struct containing the following fields:
953 refCat : `lsst.afw.catalog.SimpleCatalog`
954 A catalog of reference objects with the standard
955 schema, as documented in the main doc string for
956 `LoadReferenceObjects`.
957 The catalog is guaranteed to be contiguous.
958 fluxField : `str`
959 Name of flux field for specified `filterName`.
961 Notes
962 -----
963 The search algorithm works by searching in a region in sky
964 coordinates whose center is the center of the bbox and radius
965 is large enough to just include all 4 corners of the bbox.
966 Stars that lie outside the bbox are then trimmed from the list.
967 """
968 circle = self._calculateCircle(bbox, wcs)
970 # find objects in circle
971 self.log.info("Loading reference objects using center %s and radius %s deg" %
972 (circle.coord, circle.radius.asDegrees()))
973 loadRes = self.loadSkyCircle(circle.coord, circle.radius, filterName=filterName, epoch=epoch,
974 centroids=True)
975 refCat = loadRes.refCat
976 numFound = len(refCat)
978 # trim objects outside bbox
979 refCat = self._trimToBBox(refCat=refCat, bbox=circle.bbox, wcs=wcs)
980 numTrimmed = numFound - len(refCat)
981 self.log.debug("trimmed %d out-of-bbox objects, leaving %d", numTrimmed, len(refCat))
982 self.log.info("Loaded %d reference objects", len(refCat))
984 # make sure catalog is contiguous
985 if not refCat.isContiguous():
986 loadRes.refCat = refCat.copy(deep=True)
988 return loadRes
990 @abc.abstractmethod
991 def loadSkyCircle(self, ctrCoord, radius, filterName=None, epoch=None, centroids=False):
992 """Load reference objects that overlap a circular sky region.
994 Parameters
995 ----------
996 ctrCoord : `lsst.geom.SpherePoint`
997 ICRS center of search region.
998 radius : `lsst.geom.Angle`
999 Radius of search region.
1000 filterName : `str` (optional)
1001 Name of filter, or `None` or `""` for the default filter.
1002 This is used for flux values in case we have flux limits
1003 (which are not yet implemented).
1004 epoch : `astropy.time.Time` (optional)
1005 Epoch to which to correct proper motion and parallax,
1006 or None to not apply such corrections.
1007 centroids : `bool` (optional)
1008 Add centroid fields to the loaded Schema. ``loadPixelBox`` expects
1009 these fields to exist.
1011 Returns
1012 -------
1013 results : `lsst.pipe.base.Struct`
1014 A Struct containing the following fields:
1015 refCat : `lsst.afw.catalog.SimpleCatalog`
1016 A catalog of reference objects with the standard
1017 schema, as documented in the main doc string for
1018 `LoadReferenceObjects`.
1019 The catalog is guaranteed to be contiguous.
1020 fluxField : `str`
1021 Name of flux field for specified `filterName`.
1023 Notes
1024 -----
1025 Note that subclasses are responsible for performing the proper motion
1026 correction, since this is the lowest-level interface for retrieving
1027 the catalog.
1028 """
1029 return
1031 @staticmethod
1032 def _trimToBBox(refCat, bbox, wcs):
1033 """Remove objects outside a given pixel bounding box and set
1034 centroid and hasCentroid fields.
1036 Parameters
1037 ----------
1038 refCat : `lsst.afw.table.SimpleCatalog`
1039 A catalog of objects. The schema must include fields
1040 "coord", "centroid" and "hasCentroid".
1041 The "coord" field is read.
1042 The "centroid" and "hasCentroid" fields are set.
1043 bbox : `lsst.geom.Box2D`
1044 Pixel region
1045 wcs : `lsst.afw.geom.SkyWcs`
1046 WCS; used to convert sky coordinates to pixel positions.
1048 @return a catalog of reference objects in bbox, with centroid and hasCentroid fields set
1049 """
1050 afwTable.updateRefCentroids(wcs, refCat)
1051 centroidKey = afwTable.Point2DKey(refCat.schema["centroid"])
1052 retStarCat = type(refCat)(refCat.table)
1053 for star in refCat:
1054 point = star.get(centroidKey)
1055 if bbox.contains(point):
1056 retStarCat.append(star)
1057 return retStarCat
1059 def _addFluxAliases(self, schema):
1060 """Add aliases for camera filter fluxes to the schema.
1062 If self.config.defaultFilter then adds these aliases:
1063 camFlux: <defaultFilter>_flux
1064 camFluxErr: <defaultFilter>_fluxErr, if the latter exists
1066 For each camFilter: refFilter in self.config.filterMap adds these aliases:
1067 <camFilter>_camFlux: <refFilter>_flux
1068 <camFilter>_camFluxErr: <refFilter>_fluxErr, if the latter exists
1070 Parameters
1071 ----------
1072 schema : `lsst.afw.table.Schema`
1073 Schema for reference catalog.
1075 Raises
1076 ------
1077 RuntimeError
1078 If any reference flux field is missing from the schema.
1079 """
1080 aliasMap = schema.getAliasMap()
1082 if self.config.anyFilterMapsToThis is not None:
1083 refFluxName = self.config.anyFilterMapsToThis + "_flux"
1084 if refFluxName not in schema:
1085 msg = f"Unknown reference filter for anyFilterMapsToThis='{refFluxName}'"
1086 raise RuntimeError(msg)
1087 aliasMap.set("anyFilterMapsToThis", refFluxName)
1088 return # this is mutually exclusive with filterMap
1090 def addAliasesForOneFilter(filterName, refFilterName):
1091 """Add aliases for a single filter
1093 Parameters
1094 ----------
1095 filterName : `str` (optional)
1096 Camera filter name. The resulting alias name is
1097 <filterName>_camFlux, or simply "camFlux" if `filterName`
1098 is `None` or `""`.
1099 refFilterName : `str`
1100 Reference catalog filter name; the field
1101 <refFilterName>_flux must exist.
1102 """
1103 camFluxName = filterName + "_camFlux" if filterName is not None else "camFlux"
1104 refFluxName = refFilterName + "_flux"
1105 if refFluxName not in schema:
1106 raise RuntimeError("Unknown reference filter %s" % (refFluxName,))
1107 aliasMap.set(camFluxName, refFluxName)
1108 refFluxErrName = refFluxName + "Err"
1109 if refFluxErrName in schema:
1110 camFluxErrName = camFluxName + "Err"
1111 aliasMap.set(camFluxErrName, refFluxErrName)
1113 if self.config.defaultFilter:
1114 addAliasesForOneFilter(None, self.config.defaultFilter)
1116 for filterName, refFilterName in self.config.filterMap.items():
1117 addAliasesForOneFilter(filterName, refFilterName)
1119 @staticmethod
1120 def makeMinimalSchema(filterNameList, *, addCentroid=False,
1121 addIsPhotometric=False, addIsResolved=False,
1122 addIsVariable=False, coordErrDim=2,
1123 addProperMotion=False, properMotionErrDim=2,
1124 addParallax=False):
1125 """Make a standard schema for reference object catalogs.
1127 Parameters
1128 ----------
1129 filterNameList : `list` of `str`
1130 List of filter names. Used to create <filterName>_flux fields.
1131 addIsPhotometric : `bool`
1132 If True then add field "photometric".
1133 addIsResolved : `bool`
1134 If True then add field "resolved".
1135 addIsVariable : `bool`
1136 If True then add field "variable".
1137 coordErrDim : `int`
1138 Number of coord error fields; must be one of 0, 2, 3:
1140 - If 2 or 3: add fields "coord_raErr" and "coord_decErr".
1141 - If 3: also add field "coord_radecErr".
1142 addProperMotion : `bool`
1143 If True add fields "epoch", "pm_ra", "pm_dec" and "pm_flag".
1144 properMotionErrDim : `int`
1145 Number of proper motion error fields; must be one of 0, 2, 3;
1146 ignored if addProperMotion false:
1147 - If 2 or 3: add fields "pm_raErr" and "pm_decErr".
1148 - If 3: also add field "pm_radecErr".
1149 addParallax : `bool`
1150 If True add fields "epoch", "parallax", "parallaxErr"
1151 and "parallax_flag".
1153 Returns
1154 -------
1155 schema : `lsst.afw.table.Schema`
1156 Schema for reference catalog, an
1157 `lsst.afw.table.SimpleCatalog`.
1159 Notes
1160 -----
1161 Reference catalogs support additional covariances, such as
1162 covariance between RA and proper motion in declination,
1163 that are not supported by this method, but can be added after
1164 calling this method.
1165 """
1166 schema = afwTable.SimpleTable.makeMinimalSchema()
1167 if addCentroid:
1168 afwTable.Point2DKey.addFields(
1169 schema,
1170 "centroid",
1171 "centroid on an exposure, if relevant",
1172 "pixel",
1173 )
1174 schema.addField(
1175 field="hasCentroid",
1176 type="Flag",
1177 doc="is position known?",
1178 )
1179 for filterName in filterNameList:
1180 schema.addField(
1181 field="%s_flux" % (filterName,),
1182 type=numpy.float64,
1183 doc="flux in filter %s" % (filterName,),
1184 units="nJy",
1185 )
1186 for filterName in filterNameList:
1187 schema.addField(
1188 field="%s_fluxErr" % (filterName,),
1189 type=numpy.float64,
1190 doc="flux uncertainty in filter %s" % (filterName,),
1191 units="nJy",
1192 )
1193 if addIsPhotometric:
1194 schema.addField(
1195 field="photometric",
1196 type="Flag",
1197 doc="set if the object can be used for photometric calibration",
1198 )
1199 if addIsResolved:
1200 schema.addField(
1201 field="resolved",
1202 type="Flag",
1203 doc="set if the object is spatially resolved",
1204 )
1205 if addIsVariable:
1206 schema.addField(
1207 field="variable",
1208 type="Flag",
1209 doc="set if the object has variable brightness",
1210 )
1211 if coordErrDim not in (0, 2, 3):
1212 raise ValueError("coordErrDim={}; must be (0, 2, 3)".format(coordErrDim))
1213 if coordErrDim > 0:
1214 afwTable.CovarianceMatrix2fKey.addFields(
1215 schema=schema,
1216 prefix="coord",
1217 names=["ra", "dec"],
1218 units=["rad", "rad"],
1219 diagonalOnly=(coordErrDim == 2),
1220 )
1222 if addProperMotion or addParallax:
1223 schema.addField(
1224 field="epoch",
1225 type=numpy.float64,
1226 doc="date of observation (TAI, MJD)",
1227 units="day",
1228 )
1230 if addProperMotion:
1231 schema.addField(
1232 field="pm_ra",
1233 type="Angle",
1234 doc="proper motion in the right ascension direction = dra/dt * cos(dec)",
1235 units="rad/year",
1236 )
1237 schema.addField(
1238 field="pm_dec",
1239 type="Angle",
1240 doc="proper motion in the declination direction",
1241 units="rad/year",
1242 )
1243 if properMotionErrDim not in (0, 2, 3):
1244 raise ValueError("properMotionErrDim={}; must be (0, 2, 3)".format(properMotionErrDim))
1245 if properMotionErrDim > 0:
1246 afwTable.CovarianceMatrix2fKey.addFields(
1247 schema=schema,
1248 prefix="pm",
1249 names=["ra", "dec"],
1250 units=["rad/year", "rad/year"],
1251 diagonalOnly=(properMotionErrDim == 2),
1252 )
1253 schema.addField(
1254 field="pm_flag",
1255 type="Flag",
1256 doc="Set if proper motion or proper motion error is bad",
1257 )
1259 if addParallax:
1260 schema.addField(
1261 field="parallax",
1262 type="Angle",
1263 doc="parallax",
1264 units="rad",
1265 )
1266 schema.addField(
1267 field="parallaxErr",
1268 type="Angle",
1269 doc="uncertainty in parallax",
1270 units="rad",
1271 )
1272 schema.addField(
1273 field="parallax_flag",
1274 type="Flag",
1275 doc="Set if parallax or parallax error is bad",
1276 )
1277 return schema
1279 def _calculateCircle(self, bbox, wcs):
1280 """Compute on-sky center and radius of search region.
1282 Parameters
1283 ----------
1284 bbox : `lsst.geom.Box2I` or `lsst.geom.Box2D`
1285 Pixel bounding box.
1286 wcs : `lsst.afw.geom.SkyWcs`
1287 WCS; used to convert pixel positions to sky coordinates.
1289 Returns
1290 -------
1291 results : `lsst.pipe.base.Struct`
1292 A Struct containing:
1294 - coord : `lsst.geom.SpherePoint`
1295 ICRS center of the search region.
1296 - radius : `lsst.geom.Angle`
1297 Radius of the search region.
1298 - bbox : `lsst.geom.Box2D`
1299 Bounding box used to compute the circle.
1300 """
1301 bbox = lsst.geom.Box2D(bbox) # make sure bbox is double and that we have a copy
1302 bbox.grow(self.config.pixelMargin)
1303 coord = wcs.pixelToSky(bbox.getCenter())
1304 radius = max(coord.separation(wcs.pixelToSky(pp)) for pp in bbox.getCorners())
1305 return pipeBase.Struct(coord=coord, radius=radius, bbox=bbox)
1307 def getMetadataBox(self, bbox, wcs, filterName=None, photoCalib=None, epoch=None):
1308 """Return metadata about the load.
1310 This metadata is used for reloading the catalog (e.g., for
1311 reconstituting a normalised match list.
1313 Parameters
1314 ----------
1315 bbox : `lsst.geom.Box2I` or `lsst.geom.Box2D`
1316 Pixel bounding box.
1317 wcs : `lsst.afw.geom.SkyWcs`
1318 WCS; used to convert pixel positions to sky coordinates.
1319 filterName : `str`
1320 Name of camera filter, or `None` or `""` for the default
1321 filter.
1322 photoCalib : `lsst.afw.image.PhotoCalib` (optional)
1323 Calibration, or `None` if unknown.
1324 epoch : `astropy.time.Time` (optional)
1325 Epoch to which to correct proper motion and parallax,
1326 or None to not apply such corrections.
1328 Returns
1329 -------
1330 metadata : lsst.daf.base.PropertyList
1331 Metadata about the load.
1332 """
1333 circle = self._calculateCircle(bbox, wcs)
1334 return self.getMetadataCircle(circle.coord, circle.radius, filterName, photoCalib=photoCalib,
1335 epoch=epoch)
1337 def getMetadataCircle(self, coord, radius, filterName, photoCalib=None, epoch=None):
1338 """Return metadata about the load.
1340 This metadata is used for reloading the catalog (e.g., for
1341 reconstituting a normalised match list.
1343 Parameters
1344 ----------
1345 coord : `lsst.geom.SpherePoint`
1346 ICRS center of the search region.
1347 radius : `lsst.geom.Angle`
1348 Radius of the search region.
1349 filterName : `str`
1350 Name of camera filter, or `None` or `""` for the default
1351 filter.
1352 photoCalib : `lsst.afw.image.PhotoCalib` (optional)
1353 Calibration, or `None` if unknown.
1354 epoch : `astropy.time.Time` (optional)
1355 Epoch to which to correct proper motion and parallax,
1356 or None to not apply such corrections.
1358 Returns
1359 -------
1360 metadata : lsst.daf.base.PropertyList
1361 Metadata about the load
1362 """
1363 md = PropertyList()
1364 md.add('RA', coord.getRa().asDegrees(), 'field center in degrees')
1365 md.add('DEC', coord.getDec().asDegrees(), 'field center in degrees')
1366 md.add('RADIUS', radius.asDegrees(), 'field radius in degrees, minimum')
1367 md.add('SMATCHV', 1, 'SourceMatchVector version number')
1368 filterName = "UNKNOWN" if filterName is None else str(filterName)
1369 md.add('FILTER', filterName, 'filter name for photometric data')
1370 md.add('EPOCH', "NONE" if epoch is None else epoch.mjd, 'Epoch (TAI MJD) for catalog')
1371 return md
1373 def joinMatchListWithCatalog(self, matchCat, sourceCat):
1374 """Relink an unpersisted match list to sources and reference
1375 objects.
1377 A match list is persisted and unpersisted as a catalog of IDs
1378 produced by afw.table.packMatches(), with match metadata
1379 (as returned by the astrometry tasks) in the catalog's metadata
1380 attribute. This method converts such a match catalog into a match
1381 list, with links to source records and reference object records.
1383 Parameters
1384 ----------
1385 matchCat : `lsst.afw.table.BaseCatalog`
1386 Unperisted packed match list.
1387 ``matchCat.table.getMetadata()`` must contain match metadata,
1388 as returned by the astrometry tasks.
1389 sourceCat : `lsst.afw.table.SourceCatalog`
1390 Source catalog. As a side effect, the catalog will be sorted
1391 by ID.
1393 Returns
1394 -------
1395 matchList : `lsst.afw.table.ReferenceMatchVector`
1396 Match list.
1397 """
1398 return joinMatchListWithCatalogImpl(self, matchCat, sourceCat)
1400 def applyProperMotions(self, catalog, epoch):
1401 """Apply proper motion correction to a reference catalog.
1403 Adjust position and position error in the ``catalog``
1404 for proper motion to the specified ``epoch``,
1405 modifying the catalog in place.
1407 Parameters
1408 ----------
1409 catalog : `lsst.afw.table.SimpleCatalog`
1410 Catalog of positions, containing:
1412 - Coordinates, retrieved by the table's coordinate key.
1413 - ``coord_raErr`` : Error in Right Ascension (rad).
1414 - ``coord_decErr`` : Error in Declination (rad).
1415 - ``pm_ra`` : Proper motion in Right Ascension (rad/yr,
1416 East positive)
1417 - ``pm_raErr`` : Error in ``pm_ra`` (rad/yr), optional.
1418 - ``pm_dec`` : Proper motion in Declination (rad/yr,
1419 North positive)
1420 - ``pm_decErr`` : Error in ``pm_dec`` (rad/yr), optional.
1421 - ``epoch`` : Mean epoch of object (an astropy.time.Time)
1422 epoch : `astropy.time.Time`
1423 Epoch to which to correct proper motion,
1424 """
1425 if ("epoch" not in catalog.schema or "pm_ra" not in catalog.schema or "pm_dec" not in catalog.schema):
1426 if self.config.requireProperMotion:
1427 raise RuntimeError("Proper motion correction required but not available from catalog")
1428 self.log.warn("Proper motion correction not available from catalog")
1429 return
1430 applyProperMotionsImpl(self.log, catalog, epoch)
1433def joinMatchListWithCatalogImpl(refObjLoader, matchCat, sourceCat):
1434 """Relink an unpersisted match list to sources and reference
1435 objects.
1437 A match list is persisted and unpersisted as a catalog of IDs
1438 produced by afw.table.packMatches(), with match metadata
1439 (as returned by the astrometry tasks) in the catalog's metadata
1440 attribute. This method converts such a match catalog into a match
1441 list, with links to source records and reference object records.
1443 Parameters
1444 ----------
1445 refObjLoader
1446 Reference object loader to use in getting reference objects
1447 matchCat : `lsst.afw.table.BaseCatalog`
1448 Unperisted packed match list.
1449 ``matchCat.table.getMetadata()`` must contain match metadata,
1450 as returned by the astrometry tasks.
1451 sourceCat : `lsst.afw.table.SourceCatalog`
1452 Source catalog. As a side effect, the catalog will be sorted
1453 by ID.
1455 Returns
1456 -------
1457 matchList : `lsst.afw.table.ReferenceMatchVector`
1458 Match list.
1459 """
1460 matchmeta = matchCat.table.getMetadata()
1461 version = matchmeta.getInt('SMATCHV')
1462 if version != 1:
1463 raise ValueError('SourceMatchVector version number is %i, not 1.' % version)
1464 filterName = matchmeta.getString('FILTER').strip()
1465 try:
1466 epoch = matchmeta.getDouble('EPOCH')
1467 except (pexExcept.NotFoundError, pexExcept.TypeError):
1468 epoch = None # Not present, or not correct type means it's not set
1469 if 'RADIUS' in matchmeta:
1470 # This is a circle style metadata, call loadSkyCircle
1471 ctrCoord = lsst.geom.SpherePoint(matchmeta.getDouble('RA'),
1472 matchmeta.getDouble('DEC'), lsst.geom.degrees)
1473 rad = matchmeta.getDouble('RADIUS') * lsst.geom.degrees
1474 refCat = refObjLoader.loadSkyCircle(ctrCoord, rad, filterName, epoch=epoch).refCat
1475 elif "INNER_UPPER_LEFT_RA" in matchmeta:
1476 # This is the sky box type (only triggers in the LoadReferenceObject class, not task)
1477 # Only the outer box is required to be loaded to get the maximum region, all filtering
1478 # will be done by the unpackMatches function, and no spatial filtering needs to be done
1479 # by the refObjLoader
1480 box = []
1481 for place in ("UPPER_LEFT", "UPPER_RIGHT", "LOWER_LEFT", "LOWER_RIGHT"):
1482 coord = lsst.geom.SpherePoint(matchmeta.getDouble(f"OUTER_{place}_RA"),
1483 matchmeta.getDouble(f"OUTER_{place}_DEC"),
1484 lsst.geom.degrees).getVector()
1485 box.append(coord)
1486 outerBox = sphgeom.ConvexPolygon(box)
1487 refCat = refObjLoader.loadRegion(outerBox, filterName=filterName, epoch=epoch).refCat
1489 refCat.sort()
1490 sourceCat.sort()
1491 return afwTable.unpackMatches(matchCat, refCat, sourceCat)
1494def applyProperMotionsImpl(log, catalog, epoch):
1495 """Apply proper motion correction to a reference catalog.
1497 Adjust position and position error in the ``catalog``
1498 for proper motion to the specified ``epoch``,
1499 modifying the catalog in place.
1501 Parameters
1502 ----------
1503 log : `lsst.log.Log`
1504 Log object to write to.
1505 catalog : `lsst.afw.table.SimpleCatalog`
1506 Catalog of positions, containing:
1508 - Coordinates, retrieved by the table's coordinate key.
1509 - ``coord_raErr`` : Error in Right Ascension (rad).
1510 - ``coord_decErr`` : Error in Declination (rad).
1511 - ``pm_ra`` : Proper motion in Right Ascension (rad/yr,
1512 East positive)
1513 - ``pm_raErr`` : Error in ``pm_ra`` (rad/yr), optional.
1514 - ``pm_dec`` : Proper motion in Declination (rad/yr,
1515 North positive)
1516 - ``pm_decErr`` : Error in ``pm_dec`` (rad/yr), optional.
1517 - ``epoch`` : Mean epoch of object (an astropy.time.Time)
1518 epoch : `astropy.time.Time`
1519 Epoch to which to correct proper motion.
1520 """
1521 if "epoch" not in catalog.schema or "pm_ra" not in catalog.schema or "pm_dec" not in catalog.schema:
1522 log.warn("Proper motion correction not available from catalog")
1523 return
1524 if not catalog.isContiguous():
1525 raise RuntimeError("Catalog must be contiguous")
1526 catEpoch = astropy.time.Time(catalog["epoch"], scale="tai", format="mjd")
1527 log.info("Correcting reference catalog for proper motion to %r", epoch)
1528 # Use `epoch.tai` to make sure the time difference is in TAI
1529 timeDiffsYears = (epoch.tai - catEpoch).to(astropy.units.yr).value
1530 coordKey = catalog.table.getCoordKey()
1531 # Compute the offset of each object due to proper motion
1532 # as components of the arc of a great circle along RA and Dec
1533 pmRaRad = catalog["pm_ra"]
1534 pmDecRad = catalog["pm_dec"]
1535 offsetsRaRad = pmRaRad*timeDiffsYears
1536 offsetsDecRad = pmDecRad*timeDiffsYears
1537 # Compute the corresponding bearing and arc length of each offset
1538 # due to proper motion, and apply the offset
1539 # The factor of 1e6 for computing bearing is intended as
1540 # a reasonable scale for typical values of proper motion
1541 # in order to avoid large errors for small values of proper motion;
1542 # using the offsets is another option, but it can give
1543 # needlessly large errors for short duration
1544 offsetBearingsRad = numpy.arctan2(pmDecRad*1e6, pmRaRad*1e6)
1545 offsetAmountsRad = numpy.hypot(offsetsRaRad, offsetsDecRad)
1546 for record, bearingRad, amountRad in zip(catalog, offsetBearingsRad, offsetAmountsRad):
1547 record.set(coordKey,
1548 record.get(coordKey).offset(bearing=bearingRad*lsst.geom.radians,
1549 amount=amountRad*lsst.geom.radians))
1550 # Increase error in RA and Dec based on error in proper motion
1551 if "coord_raErr" in catalog.schema:
1552 catalog["coord_raErr"] = numpy.hypot(catalog["coord_raErr"],
1553 catalog["pm_raErr"]*timeDiffsYears)
1554 if "coord_decErr" in catalog.schema:
1555 catalog["coord_decErr"] = numpy.hypot(catalog["coord_decErr"],
1556 catalog["pm_decErr"]*timeDiffsYears)