Make trailedAssociatorTask

python/lsst/ap/association/__init__.py

@@ -20,6 +20,7 @@
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 from .version import *
+from .trailedSourceFilter import *
 from .association import *
 from .diaForcedSource import *
 from .loadDiaCatalogs import *

python/lsst/ap/association/association.py

@@ -32,6 +32,7 @@
 import lsst.pex.config as pexConfig
 import lsst.pipe.base as pipeBase
 from lsst.utils.timer import timeMethod
+from .trailedSourceFilter import TrailedSourceFilterTask
 
 # Enforce an error for unsafe column/array value setting in pandas.
 pd.options.mode.chained_assignment = 'raise'
@@ -40,13 +41,27 @@
 class AssociationConfig(pexConfig.Config):
     """Config class for AssociationTask.
     """
+
     maxDistArcSeconds = pexConfig.Field(
         dtype=float,
-        doc='Maximum distance in arcseconds to test for a DIASource to be a '
-        'match to a DIAObject.',
+        doc="Maximum distance in arcseconds to test for a DIASource to be a "
+        "match to a DIAObject.",
         default=1.0,
     )
 
+    trailedSourceFilter = pexConfig.ConfigurableField(
+        target=TrailedSourceFilterTask,
+        doc="Subtask to remove long trailed sources based on catalog source "
+            "morphological measurements.",
+    )
+
+    doTrailedSourceFilter = pexConfig.Field(
+        doc="Run traildeSourceFilter to remove long trailed sources from "
+            "output catalog.",
+        dtype=bool,
+        default=True,
+    )
+
 
 class AssociationTask(pipeBase.Task):
     """Associate DIAOSources into existing DIAObjects.
@@ -60,10 +75,16 @@ class AssociationTask(pipeBase.Task):
     ConfigClass = AssociationConfig
     _DefaultName = "association"
 
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        if self.config.doTrailedSourceFilter:
+            self.makeSubtask("trailedSourceFilter")
+
     @timeMethod
     def run(self,
             diaSources,
-            diaObjects):
+            diaObjects,
+            exposure_time=None):
         """Associate the new DiaSources with existing DiaObjects.
 
         Parameters
@@ -72,6 +93,8 @@ def run(self,
             New DIASources to be associated with existing DIAObjects.
         diaObjects : `pandas.DataFrame`
             Existing diaObjects from the Apdb.
+        exposure_time : `float`, optional
+            Exposure time from difference image.
 
         Returns
         -------
@@ -98,7 +121,16 @@ def run(self,
                 nUpdatedDiaObjects=0,
                 nUnassociatedDiaObjects=0)
 
-        matchResult = self.associate_sources(diaObjects, diaSources)
+        if self.config.doTrailedSourceFilter:
+            diaTrailedResult = self.trailedSourceFilter.run(diaSources, exposure_time)
+            matchResult = self.associate_sources(diaObjects, diaTrailedResult.diaSources)
+
+            self.log.warning("%i DIASources exceed maxTrailLength, dropping "
+                             "from source catalog."
+                             % len(diaTrailedResult.trailedDiaSources))
+
+        else:
+            matchResult = self.associate_sources(diaObjects, diaSources)
 
         mask = matchResult.diaSources["diaObjectId"] != 0
 

python/lsst/ap/association/diaPipe.py

@@ -28,6 +28,10 @@
 Currently loads directly from the Apdb rather than pre-loading.
 """
 
+__all__ = ("DiaPipelineConfig",
+           "DiaPipelineTask",
+           "DiaPipelineConnections")
+
 import pandas as pd
 
 import lsst.dax.apdb as daxApdb
@@ -44,10 +48,6 @@
     PackageAlertsTask)
 from lsst.ap.association.ssoAssociation import SolarSystemAssociationTask
 
-__all__ = ("DiaPipelineConfig",
-           "DiaPipelineTask",
-           "DiaPipelineConnections")
-
 
 class DiaPipelineConnections(
         pipeBase.PipelineTaskConnections,
@@ -367,8 +367,8 @@ def run(self,
         loaderResult = self.diaCatalogLoader.run(diffIm, self.apdb)
 
         # Associate new DiaSources with existing DiaObjects.
-        assocResults = self.associator.run(diaSourceTable,
-                                           loaderResult.diaObjects)
+        assocResults = self.associator.run(diaSourceTable, loaderResult.diaObjects,
+                                           exposure_time=diffIm.getInfo().getVisitInfo().getExposureTime())
         if self.config.doSolarSystemAssociation:
             ssoAssocResult = self.solarSystemAssociator.run(
                 assocResults.unAssocDiaSources,

python/lsst/ap/association/trailedSourceFilter.py

@@ -0,0 +1,112 @@
+# This file is part of ap_association.
+#
+# Developed for the LSST Data Management System.
+# This product includes software developed by the LSST Project
+# (https://www.lsst.org).
+# See the COPYRIGHT file at the top-level directory of this distribution
+# for details of code ownership.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+__all__ = ("TrailedSourceFilterTask", "TrailedSourceFilterConfig")
+
+import lsst.pex.config as pexConfig
+import lsst.pipe.base as pipeBase
+from lsst.utils.timer import timeMethod
+
+
+class TrailedSourceFilterConfig(pexConfig.Config):
+    """Config class for TrailedSourceFilterTask.
+    """
+
+    maxTrailLength = pexConfig.Field(
+        dtype=float,
+        doc="Length of long trailed sources to remove from the input catalog, "
+            "in arcseconds per second. Default comes from DMTN-199, which "
+            "requires removal of sources with trails longer than 10 "
+            "degrees/day, which is 36000/3600/24arcsec/second, or roughly"
+            "0.416 arcseconds per second.",
+        default=36000/3600.0/24.0,
+    )
+
+
+class TrailedSourceFilterTask(pipeBase.Task):
+    """Find trailed sources in DIASources and filter them as per DMTN-199
+    guidelines.
+
+    This task checks the length of trailLength in the DIASource catalog using
+    a given arcsecond/second rate from maxTrailLength and the exposure time.
+    The two values are used to calculate the maximum allowed trail length and
+    filters out any trail longer than the maximum. The maxTrailLength is
+    outlined in DMTN-199 and determines the default value.
+    """
+
+    ConfigClass = TrailedSourceFilterConfig
+    _DefaultName = "trailedSourceFilter"
+
+    @timeMethod
+    def run(self, dia_sources, exposure_time):
+        """Remove trailed sources longer than ``config.maxTrailLength`` from
+        the input catalog.
+
+        Parameters
+        ----------
+        dia_sources : `pandas.DataFrame`
+            New DIASources to be checked for trailed sources.
+        exposure_time : `float`
+            Exposure time from difference image.
+
+        Returns
+        -------
+        result : `lsst.pipe.base.Struct`
+            Results struct with components.
+
+            - ``dia_sources`` : DIASource table that is free from unwanted
+             trailed sources. (`pandas.DataFrame`)
+
+            - ``trailed_dia_sources`` : DIASources that have trails which
+            exceed maxTrailLength/second*exposure_time.
+            (`pandas.DataFrame`)
+        """
+
+        trail_mask = self._check_dia_source_trail(dia_sources, exposure_time)
+
+        return pipeBase.Struct(
+            diaSources=dia_sources[~trail_mask].reset_index(drop=True),
+            trailedDiaSources=dia_sources[trail_mask].reset_index(drop=True))
+
+    def _check_dia_source_trail(self, dia_sources, exposure_time):
+        """Find DiaSources that have long trails.
+
+        Creates a mask for sources with lengths greater than 0.416
+        arcseconds/second multiplied by the exposure time.
+
+        Parameters
+        ----------
+        dia_sources : `pandas.DataFrame`
+            Input DIASources to check for trail lengths.
+        exposure_time : `float`
+            Exposure time from difference image.
+
+        Returns
+        -------
+        trail_mask : `pandas.DataFrame`
+            Boolean mask for DIASources which are greater than the
+            cutoff length.
+        """
+
+        trail_mask = (dia_sources.loc[:, "trailLength"].values[:]
+                      >= (self.config.maxTrailLength*exposure_time))
+
+        return trail_mask

tests/test_association_task.py

@@ -22,7 +22,6 @@
 import numpy as np
 import pandas as pd
 import unittest
-
 import lsst.geom as geom
 import lsst.utils.tests
 
@@ -46,20 +45,23 @@ def setUp(self):
         self.diaSources = pd.DataFrame(data=[
             {"ra": 0.04*idx + scatter*rng.uniform(-1, 1),
              "dec": 0.04*idx + scatter*rng.uniform(-1, 1),
-             "diaSourceId": idx + 1 + self.nObjects, "diaObjectId": 0}
+             "diaSourceId": idx + 1 + self.nObjects, "diaObjectId": 0, "trailLength": 5.5*idx}
             for idx in range(self.nSources)])
         self.diaSourceZeroScatter = pd.DataFrame(data=[
             {"ra": 0.04*idx,
              "dec": 0.04*idx,
-             "diaSourceId": idx + 1 + self.nObjects, "diaObjectId": 0}
+             "diaSourceId": idx + 1 + self.nObjects, "diaObjectId": 0, "trailLength": 5.5*idx}
             for idx in range(self.nSources)])
+        self.exposure_time = 30.0
 
     def test_run(self):
         """Test the full task by associating a set of diaSources to
         existing diaObjects.
         """
-        assocTask = AssociationTask()
-        results = assocTask.run(self.diaSources, self.diaObjects)
+        config = AssociationTask.ConfigClass()
+        config.doTrailedSourceFilter = False
+        assocTask = AssociationTask(config=config)
+        results = assocTask.run(self.diaSources, self.diaObjects, exposure_time=self.exposure_time)
 
         self.assertEqual(results.nUpdatedDiaObjects, len(self.diaObjects) - 1)
         self.assertEqual(results.nUnassociatedDiaObjects, 1)
@@ -75,13 +77,32 @@ def test_run(self):
                 [0]):
             self.assertEqual(test_obj_id, expected_obj_id)
 
+    def test_run_trailed_sources(self):
+        """Test the full task by associating a set of diaSources to
+        existing diaObjects when trailed sources are filtered.
+
+        This should filter out two of the five sources based on trail length,
+        leaving one unassociated diaSource and two associated diaSources.
+        """
+        assocTask = AssociationTask()
+        results = assocTask.run(self.diaSources, self.diaObjects, exposure_time=self.exposure_time)
+
+        self.assertEqual(results.nUpdatedDiaObjects, len(self.diaObjects) - 3)
+        self.assertEqual(results.nUnassociatedDiaObjects, 3)
+        self.assertEqual(len(results.matchedDiaSources), len(self.diaObjects) - 3)
+        self.assertEqual(len(results.unAssocDiaSources), 1)
+        self.assertTrue(np.array_equal(results.matchedDiaSources["diaObjectId"].values,
+                                       [1, 2], equal_nan=True))
+        self.assertTrue(np.array_equal(results.unAssocDiaSources["diaObjectId"].values,
+                                       [0], equal_nan=True))
+
     def test_run_no_existing_objects(self):
         """Test the run method with a completely empty database.
         """
         assocTask = AssociationTask()
         results = assocTask.run(
             self.diaSources,
-            pd.DataFrame(columns=["ra", "dec", "diaObjectId"]))
+            pd.DataFrame(columns=["ra", "dec", "diaObjectId", "trailLength"]), exposure_time=self.exposure_time)
         self.assertEqual(results.nUpdatedDiaObjects, 0)
         self.assertEqual(results.nUnassociatedDiaObjects, 0)
         self.assertEqual(len(results.matchedDiaSources), 0)

tests/test_diaPipe.py

@@ -121,7 +121,7 @@ def solarSystemAssociator_run(self, unAssocDiaSources, solarSystemObjectTable, d
                                          unAssocDiaSources=MagicMock(spec=pd.DataFrame()))
 
         @lsst.utils.timer.timeMethod
-        def associator_run(self, table, diaObjects):
+        def associator_run(self, table, diaObjects, exposure):
             return lsst.pipe.base.Struct(nUpdatedDiaObjects=2, nUnassociatedDiaObjects=3,
                                          matchedDiaSources=MagicMock(spec=pd.DataFrame()),
                                          unAssocDiaSources=MagicMock(spec=pd.DataFrame()))