SkyCorrectionTask¶

class lsst.pipe.tasks.skyCorrection.SkyCorrectionTask(*args, **kwargs)¶

Bases: PipelineTask

Perform a full focal plane sky correction.

Attributes Summary

canMultiprocess

Methods Summary

`emptyMetadata`()	Empty (clear) the metadata for this Task and all sub-Tasks.
`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`(calExps, calBkgs, skyFrames, camera)	Perform sky correction on a visit.
`runQuantum`(butlerQC, inputRefs, outputRefs)	Do butler IO and transform to provide in memory objects for tasks `run` method.
`timer`(name[, logLevel])	Context manager to log performance data for an arbitrary block of code.

Attributes Documentation

canMultiprocess: ClassVar[bool] = True¶

Methods Documentation

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

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(calExps, calBkgs, skyFrames, camera)¶

Perform sky correction on a visit.

The original visit-level background is first restored to the calibrated exposure and the existing background model is inverted in-place. If doMaskObjects is True, the mask map associated with this exposure will be iteratively updated (over nIter loops) by re-estimating the background each iteration and redetecting footprints.

An initial full focal plane sky subtraction (bgModel1) will take place prior to scaling and subtracting the sky frame.

If doSky is True, the sky frame will be scaled to the flux in the input visit.

If doBgModel2 is True, a final full focal plane sky subtraction will take place after the sky frame has been subtracted.

The first N elements of the returned skyCorr will consist of inverted elements of the calexpBackground model (i.e., subtractive). All subsequent elements appended to skyCorr thereafter will be additive such that, when skyCorr is subtracted from a calexp, the net result will be to undo the initial per-detector background solution and then apply the skyCorr model thereafter. Adding skyCorr to a calexpBackground will effectively negate the calexpBackground, returning only the additive background components of the skyCorr background model.

Parameters:

calExpslist [lsst.afw.image.exposure.ExposureF]: Detector calibrated exposure images for the visit.
calBkgslist [lsst.afw.math.BackgroundList]: Detector background lists matching the calibrated exposures.
skyFrameslist [lsst.afw.image.exposure.ExposureF]: Sky frame calibration data for the input detectors.
cameralsst.afw.cameraGeom.Camera: Camera matching the input data to process.

Returns:

resultsStruct containing:

skyCorrlist [lsst.afw.math.BackgroundList]: Detector-level sky correction background lists.
calExpMosaiclsst.afw.image.exposure.ExposureF: Visit-level mosaic of the sky corrected data, binned. Analogous to calexp - skyCorr.
calBkgMosaiclsst.afw.image.exposure.ExposureF: Visit-level mosaic of the sky correction background, binned. Analogous to calexpBackground + skyCorr.

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.

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

SkyCorrectionTask¶