Add support for proper motion correction

Mainly this consists of getting the epoch (TAI MJD) of the exposure into the catalog loader.
lsst · Sep 4, 2018 · be05087 · be05087
1 parent 1b7a1d8
commit be05087
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Showing 3 changed files with 18 additions and 3 deletions.
diff --git a/python/lsst/meas/astrom/astrometry.py b/python/lsst/meas/astrom/astrometry.py
@@ -210,12 +210,14 @@ def solve(self, exposure, sourceCat):
             wcs=expMd.wcs,
             filterName=expMd.filterName,
             calib=expMd.calib,
+            epoch=expMd.epoch,
         )
         matchMeta = self.refObjLoader.getMetadataBox(
             bbox=expMd.bbox,
             wcs=expMd.wcs,
             filterName=expMd.filterName,
             calib=expMd.calib,
+            epoch=expMd.epoch,
         )
 
         if debug.display:

diff --git a/python/lsst/meas/astrom/directMatch.py b/python/lsst/meas/astrom/directMatch.py
@@ -91,22 +91,24 @@ def __init__(self, butler=None, refObjLoader=None, **kwargs):
         self.makeSubtask("sourceSelection")
         self.makeSubtask("referenceSelection")
 
-    def run(self, catalog, filterName=None):
+    def run(self, catalog, filterName=None, epoch=None):
         """!Load reference objects and match to them
 
         @param[in] catalog  Catalog to match to (lsst.afw.table.SourceCatalog)
         @param[in] filterName  Name of filter, for loading fluxes (str)
+        @param[in] epoch  Epoch for proper motion and parallax correction
+                          (an astropy.time.Time), or None
         @return Struct with matches (lsst.afw.table.SourceMatchVector) and
             matchMeta (lsst.meas.astrom.MatchMetadata)
         """
         circle = self.calculateCircle(catalog)
-        matchMeta = self.refObjLoader.getMetadataCircle(circle.center, circle.radius, filterName)
+        matchMeta = self.refObjLoader.getMetadataCircle(circle.center, circle.radius, filterName, epoch=epoch)
         emptyResult = Struct(matches=[], matchMeta=matchMeta)
         sourceSelection = self.sourceSelection.run(catalog)
         if len(sourceSelection.sourceCat) == 0:
             self.log.warn("No objects selected from %d objects in source catalog", len(catalog))
             return emptyResult
-        refData = self.refObjLoader.loadSkyCircle(circle.center, circle.radius, filterName)
+        refData = self.refObjLoader.loadSkyCircle(circle.center, circle.radius, filterName, epoch=epoch)
         refCat = refData.refCat
         refSelection = self.referenceSelection.run(refCat)
         if len(refSelection.sourceCat) == 0:

diff --git a/python/lsst/meas/astrom/ref_match.py b/python/lsst/meas/astrom/ref_match.py
@@ -22,7 +22,10 @@
 
 __all__ = ['RefMatchConfig', 'RefMatchTask']
 
+import astropy.time
+
 import lsst.geom
+import lsst.daf.base
 import lsst.afw.math as afwMath
 import lsst.pex.config as pexConfig
 import lsst.pipe.base as pipeBase
@@ -180,14 +183,22 @@ def _getExposureMetadata(self, exposure):
         - wcs: WCS (an lsst.afw.geom.Wcs)
         - calib calibration (an lsst.afw.image.Calib), or None if unknown
         - filterName: name of filter, or None if unknown
+        - epoch: date of exposure (an astropy.time.Time), or None
         """
         exposureInfo = exposure.getInfo()
         filterName = exposureInfo.getFilter().getName() or None
         if filterName == "_unknown_":
             filterName = None
+        epoch = None
+        if exposure.getInfo().hasVisitInfo():
+            epochTaiMjd = exposure.getInfo().getVisitInfo().getDate().get(system=lsst.daf.base.MJD,
+                                                                          scale=lsst.daf.base.TAI)
+            epoch = astropy.time.Time(epochTaiMjd, scale="tai", format="mjd")
+
         return pipeBase.Struct(
             bbox=exposure.getBBox(),
             wcs=exposureInfo.getWcs(),
             calib=exposureInfo.getCalib() if exposureInfo.hasCalib() else None,
             filterName=filterName,
+            epoch=epoch,
         )