lsst.ip.isr  21.0.0-6-g4e60332+ca5c6b7ca5
straylight.py
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21 from abc import ABC, abstractmethod
22 from typing import Optional
23 
24 from lsst.pex.config import Config, Field, ListField
25 from lsst.pipe.base import Task
26 from lsst.geom import Angle
27 
28 
29 class StrayLightConfig(Config):
30  doRotatorAngleCorrection = Field(
31  dtype=bool,
32  doc="",
33  default=False,
34  )
35  # TODO DM-28093: change the doc to specify that these are physical labels
36  filters = ListField(
37  dtype=str,
38  doc="Filters that need straylight correction.",
39  default=[],
40  )
41 
42 
43 class StrayLightTask(Task):
44  """Remove stray light from instruments.
45 
46  This is a dummy task to be retargeted with an camera-specific version.
47  """
48  ConfigClass = StrayLightConfig
49  _DefaultName = "isrStrayLight"
50 
51  def readIsrData(self, dataRef, rawExposure):
52  """Read and return calibration products relevant for correcting
53  stray light in the given exposure.
54 
55  Parameters
56  ----------
57  dataRef : `daf.persistence.butlerSubset.ButlerDataRef`
58  Butler reference of the detector data to be processed
59  rawExposure : `afw.image.Exposure`
60  The raw exposure that will later be corrected with the
61  retrieved calibration data; should not be modified in this
62  method.
63 
64  Returns
65  -------
66  straylightData : `object`, optional
67  An opaque object that should be passed as the second argument to
68  the `run` method. If `None`, no stray light correction will be
69  performed for the given image. Any other object (e.g. `True`)
70  may be used to signal that stray light correction should be
71  performed even if there is nothing to read.
72 
73  Notes
74  -----
75  This method will be called only when `IsrTask` is run by the Gen2
76  Middleware (i.e. CmdLineTask).
77  """
78  return None
79 
80  def check(self, exposure):
81  """Check if stray light correction should be run.
82 
83  Parameters
84  ----------
85  exposure : `lsst.afw.image.Exposure`
86  Exposure to correct.
87  """
88  return False
89 
90  def run(self, exposure, strayLightData):
91  """Correct stray light.
92 
93  Parameters
94  ----------
95  exposure : `lsst.afw.image.Exposure`
96  Exposure to correct.
97  strayLightData : `object`, optional
98  An opaque object that contains any calibration data used to
99  correct for stray light.
100  """
101  raise NotImplementedError("Must be implemented by subclasses.")
102 
103  def checkFilter(self, exposure):
104  """Check whether we should fringe-subtract the science exposure.
105 
106  Parameters
107  ----------
108  exposure : `lsst.afw.image.Exposure`
109  Exposure to check the filter of.
110 
111  Returns
112  -------
113  needsFringe : `bool`
114  If True, then the exposure has a filter listed in the
115  configuration, and should have the fringe applied.
116  """
117  return exposure.getFilter().getName() in self.config.filters
118 
119 
120 class StrayLightData(ABC):
121  """An abstract base class for rotator-dependent stray light information.
122  """
123 
124  @abstractmethod
125  def evaluate(self, angle_start: Angle, angle_end: Optional[Angle] = None):
126  """Get a stray light array for a range of rotator angles.
127 
128  Parameters
129  ----------
130  angle_begin : `float`
131  Instrument rotation angle at the start of the exposure.
132  angle_end : `float`, optional
133  Instrument rotation angle at the end of the exposure.
134  If not provided, the returned array will reflect a snapshot at
135  `angle_start`.
136 
137  Returns
138  -------
139  array : `numpy.ndarray`
140  A stray-light background image for this exposure.
141  """
142  raise NotImplementedError("Must be implemented by subclasses.")
def evaluate(self, Angle angle_start, Optional[Angle] angle_end=None)
Definition: straylight.py:125
def run(self, exposure, strayLightData)
Definition: straylight.py:90
def readIsrData(self, dataRef, rawExposure)
Definition: straylight.py:51