CpCtiSolveTask¶

class lsst.cp.pipe.CpCtiSolveTask(**kwargs)¶

Bases: PipelineTask

Combine CTI measurements to a final calibration.

This task uses the extended pixel edge response (EPER) method as described by Snyder et al. 2021, Journal of Astronimcal Telescopes, Instruments, and Systems, 7, 048002. doi:10.1117/1.JATIS.7.4.048002

Attributes Summary

canMultiprocess

Methods Summary

`debugView`(ampName, signal, test)	Debug method for global CTI test value.
`emptyMetadata`()	Empty (clear) the metadata for this Task and all sub-Tasks.
`findTraps`(inputMeasurements, calib, detector)	Solve for serial trap parameters.
`getFullMetadata`()	Get metadata for all tasks.
`getFullName`()	Get the task name as a hierarchical name including parent task names.
`getName`()	Get the name of the task.
`getTaskDict`()	Get a dictionary of all tasks as a shallow copy.
`makeField`(doc)	Make a `lsst.pex.config.ConfigurableField` for this task.
`makeSubtask`(name, **keyArgs)	Create a subtask as a new instance as the `name` attribute of this task.
`run`(inputMeasurements, camera, inputDims)	Solve for charge transfer inefficiency from overscan measurements.
`runQuantum`(butlerQC, inputRefs, outputRefs)	Do butler IO and transform to provide in memory objects for tasks `run` method.
`solveGlobalCti`(inputMeasurements, calib, ...)	Solve for global CTI constant.
`solveLocalOffsets`(inputMeasurements, calib, ...)	Solve for local (pixel-to-pixel) electronic offsets.
`timer`(name[, logLevel])	Context manager to log performance data for an arbitrary block of code.

Attributes Documentation

canMultiprocess: ClassVar[bool] = True¶

Methods Documentation

debugView(ampName, signal, test)¶

Debug method for global CTI test value.

Parameters:

ampNamestr: Name of the amp for plot title.
signallist [float]: Image means for the input exposures.
testlist [float]: CTI test value to plot.

emptyMetadata() → None¶: Empty (clear) the metadata for this Task and all sub-Tasks.

findTraps(inputMeasurements, calib, detector)¶

Solve for serial trap parameters.

Parameters:

inputMeasurementslist [dict]

List of overscan measurements from each input exposure. Each dictionary is nested within a top level ‘CTI’ key, with measurements organized by amplifier name, containing keys:

"FIRST_MEAN": Mean value of first image column (float).
"LAST_MEAN": Mean value of last image column (float).
"IMAGE_MEAN": Mean value of the entire image region (float).
"OVERSCAN_COLUMNS": List of overscan column indicies (list [int]).
"OVERSCAN_VALUES": List of overscan column means (list [float]).

caliblsst.ip.isr.DeferredChargeCalib

Calibration to populate with values.

detectorlsst.afw.cameraGeom.Detector

Detector object containing the geometry information for the amplifiers.

Returns:

caliblsst.ip.isr.DeferredChargeCalib: Populated calibration.

Raises:

RuntimeError: Raised if no data remains after flux filtering.

Notes

The original CTISIM code uses a data model in which the “overscan” consists of the standard serial overscan bbox with the values for the last imaging data column prepended to that list. This version of the code keeps the overscan and imaging sections separate, and so a -1 offset is needed to ensure that the same columns are used for fitting between this code and CTISIM. This offset removes that last imaging data column from the count.

getFullMetadata() → TaskMetadata¶

Get metadata for all tasks.

Returns:

metadataTaskMetadata: The keys are the full task name. Values are metadata for the top-level task and all subtasks, sub-subtasks, etc.

Notes

The returned metadata includes timing information (if @timer.timeMethod is used) and any metadata set by the task. The name of each item consists of the full task name with . replaced by :, followed by . and the name of the item, e.g.:

topLevelTaskName:subtaskName:subsubtaskName.itemName

using : in the full task name disambiguates the rare situation that a task has a subtask and a metadata item with the same name.

getFullName() → str¶

Get the task name as a hierarchical name including parent task names.

Returns:

fullNamestr

The full name consists of the name of the parent task and each subtask separated by periods. For example:

The full name of top-level task “top” is simply “top”.
The full name of subtask “sub” of top-level task “top” is “top.sub”.
The full name of subtask “sub2” of subtask “sub” of top-level task “top” is “top.sub.sub2”.

getName() → str¶

Get the name of the task.

Returns:

taskNamestr: Name of the task.

See also

getFullName: Get the full name of the task.

getTaskDict() → dict[str, weakref.ReferenceType[lsst.pipe.base.task.Task]]¶

Get a dictionary of all tasks as a shallow copy.

Returns:

taskDictdict: Dictionary containing full task name: task object for the top-level task and all subtasks, sub-subtasks, etc.

classmethod makeField(doc: str) → ConfigurableField¶

Make a lsst.pex.config.ConfigurableField for this task.

Parameters:

docstr: Help text for the field.

Returns:

configurableFieldlsst.pex.config.ConfigurableField: A ConfigurableField for this task.

Examples

Provides a convenient way to specify this task is a subtask of another task.

Here is an example of use:

class OtherTaskConfig(lsst.pex.config.Config):
    aSubtask = ATaskClass.makeField("brief description of task")

makeSubtask(name: str, **keyArgs: Any) → None¶

Create a subtask as a new instance as the name attribute of this task.

Parameters:

namestr

Brief name of the subtask.

**keyArgs

Extra keyword arguments used to construct the task. The following arguments are automatically provided and cannot be overridden:

config.
parentTask.

Notes

The subtask must be defined by Task.config.name, an instance of ConfigurableField or RegistryField.

run(inputMeasurements, camera, inputDims)¶

Solve for charge transfer inefficiency from overscan measurements.

Parameters:

inputMeasurementslist [dict]

List of overscan measurements from each input exposure. Each dictionary is nested within a top level ‘CTI’ key, with measurements organized by amplifier name, containing keys:

"FIRST_MEAN": Mean value of first image column (float).
"LAST_MEAN": Mean value of last image column (float).
"IMAGE_MEAN": Mean value of the entire image region (float).
"OVERSCAN_COLUMNS": List of overscan column indicies (list [int]).
"OVERSCAN_VALUES": List of overscan column means (list [float]).

cameralsst.afw.cameraGeom.Camera

Camera geometry to use to find detectors.

inputDimslist [dict]

List of input dimensions from each input exposure.

Returns:

resultslsst.pipe.base.Struct

Result struct containing:

outputCalib: Final CTI calibration data (lsst.ip.isr.DeferredChargeCalib).

Raises:

RuntimeError: Raised if data from multiple detectors are passed in.

runQuantum(butlerQC, inputRefs, outputRefs)¶

Do butler IO and transform to provide in memory objects for tasks run method.

Parameters:

butlerQCQuantumContext: A butler which is specialized to operate in the context of a lsst.daf.butler.Quantum.
inputRefsInputQuantizedConnection: Datastructure whose attribute names are the names that identify connections defined in corresponding PipelineTaskConnections class. The values of these attributes are the lsst.daf.butler.DatasetRef objects associated with the defined input/prerequisite connections.
outputRefsOutputQuantizedConnection: Datastructure whose attribute names are the names that identify connections defined in corresponding PipelineTaskConnections class. The values of these attributes are the lsst.daf.butler.DatasetRef objects associated with the defined output connections.

solveGlobalCti(inputMeasurements, calib, detector)¶

Solve for global CTI constant.

This method solves for the mean global CTI, b.

Parameters:

inputMeasurementslist [dict]

List of overscan measurements from each input exposure. Each dictionary is nested within a top level ‘CTI’ key, with measurements organized by amplifier name, containing keys:

"FIRST_MEAN": Mean value of first image column (float).
"LAST_MEAN": Mean value of last image column (float).
"IMAGE_MEAN": Mean value of the entire image region (float).
"OVERSCAN_COLUMNS": List of overscan column indicies (list [int]).
"OVERSCAN_VALUES": List of overscan column means (list [float]).

caliblsst.ip.isr.DeferredChargeCalib

Calibration to populate with values.

detectorlsst.afw.cameraGeom.Detector

Detector object containing the geometry information for the amplifiers.

Returns:

caliblsst.ip.isr.DeferredChargeCalib: Populated calibration.

Raises:

RuntimeError: Raised if no data remains after flux filtering.

Notes

The original CTISIM code uses a data model in which the “overscan” consists of the standard serial overscan bbox with the values for the last imaging data column prepended to that list. This version of the code keeps the overscan and imaging sections separate, and so a -1 offset is needed to ensure that the same columns are used for fitting between this code and CTISIM. This offset removes that last imaging data column from the count.

solveLocalOffsets(inputMeasurements, calib, detector)¶

Solve for local (pixel-to-pixel) electronic offsets.

This method fits for au_L, the local electronic offset decay time constant, and A_L, the local electronic offset constant of proportionality.

Parameters:

inputMeasurementslist [dict]

List of overscan measurements from each input exposure. Each dictionary is nested within a top level ‘CTI’ key, with measurements organized by amplifier name, containing keys:

"FIRST_MEAN": Mean value of first image column (float).
"LAST_MEAN": Mean value of last image column (float).
"IMAGE_MEAN": Mean value of the entire image region (float).
"OVERSCAN_COLUMNS": List of overscan column indicies (list [int]).
"OVERSCAN_VALUES": List of overscan column means (list [float]).

caliblsst.ip.isr.DeferredChargeCalib

Calibration to populate with values.

detectorlsst.afw.cameraGeom.Detector

Detector object containing the geometry information for the amplifiers.

Returns:

caliblsst.ip.isr.DeferredChargeCalib: Populated calibration.

Raises:

RuntimeError: Raised if no data remains after flux filtering.

Notes

The original CTISIM code (https://github.com/Snyder005/ctisim) uses a data model in which the “overscan” consists of the standard serial overscan bbox with the values for the last imaging data column prepended to that list. This version of the code keeps the overscan and imaging sections separate, and so a -1 offset is needed to ensure that the same columns are used for fitting between this code and CTISIM. This offset removes that last imaging data column from the count.

timer(name: str, logLevel: int = 10) → Iterator[None]¶

Context manager to log performance data for an arbitrary block of code.

Parameters:

namestr: Name of code being timed; data will be logged using item name: Start and End.
logLevelint: A logging level constant.

Navigation

CpCtiSolveTask¶