22 __all__ = [
"FitSipDistortionTask",
"FitSipDistortionConfig"]
31 from lsst.utils.timer
import timeMethod
33 from .scaledPolynomialTransformFitter
import ScaledPolynomialTransformFitter, OutlierRejectionControl
34 from .sipTransform
import SipForwardTransform, SipReverseTransform, makeWcs
35 from .makeMatchStatistics
import makeMatchStatisticsInRadians
37 from .setMatchDistance
import setMatchDistance
41 """Config for FitSipDistortionTask"""
42 order = lsst.pex.config.RangeField(
43 doc=
"Order of SIP polynomial",
48 numRejIter = lsst.pex.config.RangeField(
49 doc=
"Number of rejection iterations",
54 rejSigma = lsst.pex.config.RangeField(
55 doc=
"Number of standard deviations for clipping level",
60 nClipMin = lsst.pex.config.Field(
61 doc=
"Minimum number of matches to reject when sigma-clipping",
65 nClipMax = lsst.pex.config.Field(
66 doc=
"Maximum number of matches to reject when sigma-clipping",
70 maxScatterArcsec = lsst.pex.config.RangeField(
71 doc=
"Maximum median scatter of a WCS fit beyond which the fit fails (arcsec); "
72 "be generous, as this is only intended to catch catastrophic failures",
77 refUncertainty = lsst.pex.config.Field(
78 doc=
"RMS uncertainty in reference catalog positions, in pixels. Will be added "
79 "in quadrature with measured uncertainties in the fit.",
83 nGridX = lsst.pex.config.Field(
84 doc=
"Number of X grid points used to invert the SIP reverse transform.",
88 nGridY = lsst.pex.config.Field(
89 doc=
"Number of Y grid points used to invert the SIP reverse transform.",
93 gridBorder = lsst.pex.config.Field(
94 doc=
"When setting the gird region, how much to extend the image "
95 "bounding box (in pixels) before transforming it to intermediate "
96 "world coordinates using the initial WCS.",
103 """Fit a TAN-SIP WCS given a list of reference object/source matches.
105 ConfigClass = FitSipDistortionConfig
106 _DefaultName =
"fitWcs"
109 lsst.pipe.base.Task.__init__(self, **kwargs)
116 def fitWcs(self, matches, initWcs, bbox=None, refCat=None, sourceCat=None, exposure=None):
117 """Fit a TAN-SIP WCS from a list of reference object/source matches.
121 matches : `list` of `lsst.afw.table.ReferenceMatch`
122 A sequence of reference object/source matches.
123 The following fields are read:
124 - match.first (reference object) coord
125 - match.second (source) centroid
127 The following fields are written:
128 - match.first (reference object) centroid
129 - match.second (source) centroid
130 - match.distance (on sky separation, in radians)
132 initWcs : `lsst.afw.geom.SkyWcs`
133 An initial WCS whose CD matrix is used as the final CD matrix.
134 bbox : `lsst.geom.Box2I`
135 The region over which the WCS will be valid (PARENT pixel coordinates);
136 if `None` or an empty box then computed from matches
137 refCat : `lsst.afw.table.SimpleCatalog`
138 Reference object catalog, or `None`.
139 If provided then all centroids are updated with the new WCS,
140 otherwise only the centroids for ref objects in matches are updated.
141 Required fields are "centroid_x", "centroid_y", "coord_ra", and "coord_dec".
142 sourceCat : `lsst.afw.table.SourceCatalog`
143 Source catalog, or `None`.
144 If provided then coords are updated with the new WCS;
145 otherwise only the coords for sources in matches are updated.
146 Required input fields are "slot_Centroid_x", "slot_Centroid_y",
147 "slot_Centroid_xErr", "slot_Centroid_yErr", and optionally
148 "slot_Centroid_x_y_Cov". The "coord_ra" and "coord_dec" fields
149 will be updated but are not used as input.
150 exposure : `lsst.afw.image.Exposure`
151 An Exposure or other displayable image on which matches can be
152 overplotted. Ignored (and may be `None`) if display-based debugging
153 is not enabled via lsstDebug.
157 An lsst.pipe.base.Struct with the following fields:
158 - wcs : `lsst.afw.geom.SkyWcs`
160 - scatterOnSky : `lsst.geom.Angle`
161 The median on-sky separation between reference objects and
162 sources in "matches", as an `lsst.geom.Angle`
171 for match
in matches:
172 bbox.include(match.second.getCentroid())
184 revFitter = ScaledPolynomialTransformFitter.fromMatches(self.config.order, matches, wcs,
185 self.config.refUncertainty)
187 for nIter
in range(self.config.numRejIter):
188 revFitter.updateModel()
189 intrinsicScatter = revFitter.updateIntrinsicScatter()
190 clippedSigma, nRejected = revFitter.rejectOutliers(self.
outlierRejectionCtrloutlierRejectionCtrl)
192 "Iteration {0}: intrinsic scatter is {1:4.3f} pixels, "
193 "rejected {2} outliers at {3:3.2f} sigma.".format(
194 nIter+1, intrinsicScatter, nRejected, clippedSigma
198 displayFrame = self.
displaydisplay(revFitter, exposure=exposure, bbox=bbox,
199 frame=displayFrame, displayPause=displayPause)
201 revScaledPoly = revFitter.getTransform()
205 sipReverse = SipReverseTransform.convert(revScaledPoly, wcs.getPixelOrigin(), cdMatrix)
213 gridBBoxPix.grow(self.config.gridBorder)
219 for point
in gridBBoxPix.getCorners():
221 gridBBoxIwc.include(cdMatrix(point))
222 fwdFitter = ScaledPolynomialTransformFitter.fromGrid(self.config.order, gridBBoxIwc,
223 self.config.nGridX, self.config.nGridY,
227 fwdScaledPoly = fwdFitter.getTransform()
228 sipForward = SipForwardTransform.convert(fwdScaledPoly, wcs.getPixelOrigin(), cdMatrix)
232 wcs =
makeWcs(sipForward, sipReverse, wcs.getSkyOrigin())
234 if refCat
is not None:
235 self.log.debug(
"Updating centroids in refCat")
238 self.log.warn(
"Updating reference object centroids in match list; refCat is None")
241 if sourceCat
is not None:
242 self.log.debug(
"Updating coords in sourceCat")
245 self.log.warn(
"Updating source coords in match list; sourceCat is None")
248 self.log.debug(
"Updating distance in match list")
252 scatterOnSky = stats.getValue()*lsst.geom.radians
254 if scatterOnSky.asArcseconds() > self.config.maxScatterArcsec:
255 raise lsst.pipe.base.TaskError(
256 "Fit failed: median scatter on sky = %0.3f arcsec > %0.3f config.maxScatterArcsec" %
257 (scatterOnSky.asArcseconds(), self.config.maxScatterArcsec))
259 return lsst.pipe.base.Struct(
261 scatterOnSky=scatterOnSky,
264 def display(self, revFitter, exposure=None, bbox=None, frame=0, pause=True):
265 """Display positions and outlier status overlaid on an image.
267 This method is called by fitWcs when display debugging is enabled. It
268 always drops into pdb before returning to allow interactive inspection,
269 and hence it should never be called in non-interactive contexts.
273 revFitter : :cpp:class:`lsst::meas::astrom::ScaledPolynomialTransformFitter`
274 Fitter object initialized with `fromMatches` for fitting a "reverse"
275 distortion: the mapping from intermediate world coordinates to
277 exposure : :cpp:class:`lsst::afw::image::Exposure`
278 An Exposure or other displayable image on which matches can be
280 bbox : :cpp:class:`lsst::afw::geom::Box2I`
281 Bounding box of the region on which matches should be plotted.
283 data = revFitter.getData()
284 disp = lsst.afw.display.getDisplay(frame=frame)
285 if exposure
is not None:
287 elif bbox
is not None:
288 disp.mtv(exposure=lsst.afw.image.ExposureF(bbox))
290 raise TypeError(
"At least one of 'exposure' and 'bbox' must be provided.")
291 data = revFitter.getData()
293 srcErrKey = lsst.afw.table.CovarianceMatrix2fKey(data.schema[
"src"], [
"x",
"y"])
296 rejectedKey = data.schema.find(
"rejected").key
297 with disp.Buffering():
299 colors = ((lsst.afw.display.RED, lsst.afw.display.GREEN)
300 if not record.get(rejectedKey)
else
301 (lsst.afw.display.MAGENTA, lsst.afw.display.CYAN))
302 rx, ry = record.get(refKey)
303 disp.dot(
"x", rx, ry, size=10, ctype=colors[0])
304 mx, my = record.get(modelKey)
305 disp.dot(
"o", mx, my, size=10, ctype=colors[0])
306 disp.line([(rx, ry), (mx, my)], ctype=colors[0])
307 sx, sy = record.get(srcKey)
308 sErr = record.get(srcErrKey)
309 sEllipse = lsst.afw.geom.Quadrupole(sErr[0, 0], sErr[1, 1], sErr[0, 1])
310 disp.dot(sEllipse, sx, sy, ctype=colors[1])
311 if pause
or pause
is None:
312 print(
"Dropping into debugger to allow inspection of display. Type 'continue' when done.")
320 """Generate a guess Wcs from the astrometric matches
322 We create a Wcs anchored at the center of the matches, with the scale
323 of the input Wcs. This is necessary because the Wcs may have a very
324 approximation position (as is common with telescoped-generated Wcs).
325 We're using the best of each: positions from the matches, and scale
330 matches : list of :cpp:class:`lsst::afw::table::ReferenceMatch`
331 A sequence of reference object/source matches.
332 The following fields are read:
334 - match.first (reference object) coord
335 - match.second (source) centroid
337 wcs : :cpp:class:`lsst::afw::geom::SkyWcs`
338 An initial WCS whose CD matrix is used as the CD matrix of the
343 newWcs : `lsst.afw.geom.SkyWcs`
350 crval += mm.first.getCoord().getVector()
351 crpix /= len(matches)
352 crval /= len(matches)
353 cd = wcs.getCdMatrix()
def makeInitialWcs(self, matches, wcs)
def __init__(self, **kwargs)
def fitWcs(self, matches, initWcs, bbox=None, refCat=None, sourceCat=None, exposure=None)
def display(self, revFitter, exposure=None, bbox=None, frame=0, pause=True)
std::shared_ptr< SkyWcs > makeSkyWcs(daf::base::PropertySet &metadata, bool strip=false)
void updateRefCentroids(geom::SkyWcs const &wcs, ReferenceCollection &refList)
void updateSourceCoords(geom::SkyWcs const &wcs, SourceCollection &sourceList)
def setMatchDistance(matches)
afw::math::Statistics makeMatchStatisticsInRadians(afw::geom::SkyWcs const &wcs, std::vector< MatchT > const &matchList, int const flags, afw::math::StatisticsControl const &sctrl=afw::math::StatisticsControl())
Compute statistics of on-sky radial separation for a match list, in radians.
std::shared_ptr< afw::geom::SkyWcs > makeWcs(SipForwardTransform const &sipForward, SipReverseTransform const &sipReverse, geom::SpherePoint const &skyOrigin)
Create a new TAN SIP Wcs from a pair of SIP transforms and the sky origin.