DeferredChargeCalib

class lsst.ip.isr.DeferredChargeCalib(**kwargs)

Bases: lsst.ip.isr.IsrCalib

Calibration containing deferred charge/CTI parameters.

Parameters:

**kwargs

Additional parameters to pass to parent constructor.

Notes

The charge transfer inefficiency attributes stored are:

driftScale : dict [str, float]

A dictionary, keyed by amplifier name, of the local electronic offset drift scale parameter, A_L in Snyder+2021.

decayTime : dict [str, float]

A dictionary, keyed by amplifier name, of the local electronic offset decay time, tau_L in Snyder+2021.

globalCti : dict [str, float]

A dictionary, keyed by amplifier name, of the mean global CTI paramter, b in Snyder+2021.

serialTraps : dict [str, lsst.ip.isr.SerialTrap]

A dictionary, keyed by amplifier name, containing a single serial trap for each amplifier.

Attributes Summary

requiredAttributes

Methods Summary

apply(target)	Method to apply the calibration to the target object.
calibInfoFromDict(dictionary)	Handle common keywords.
determineCalibClass(metadata, message)	Attempt to find calibration class in metadata.
fromDetector(detector)	Read metadata parameters from a detector.
fromDict(dictionary)	Construct a calibration from a dictionary of properties.
fromTable(tableList)	Construct calibration from a list of tables.
getMetadata()	Retrieve metadata associated with this calibration.
readFits(filename, **kwargs)	Read calibration data from a FITS file.
readText(filename, **kwargs)	Read calibration representation from a yaml/ecsv file.
setMetadata(metadata)	Store a copy of the supplied metadata with this calibration.
toDict()	Return a dictionary containing the calibration properties.
toTable()	Construct a list of tables containing the information in this calibration.
updateMetadata([camera, detector, …])	Update metadata keywords with new values.
validate([other])	Validate that this calibration is defined and can be used.
writeFits(filename)	Write calibration data to a FITS file.
writeText(filename[, format])	Write the calibration data to a text file.

Attributes Documentation

requiredAttributes

Methods Documentation

apply(target)

Method to apply the calibration to the target object.

Parameters:

target : object

Thing to validate against.

Returns:

valid : bool

Returns true if the calibration was applied correctly.

Raises:

NotImplementedError

Raised if not implemented.

calibInfoFromDict(dictionary)

Handle common keywords.

This isn’t an ideal solution, but until all calibrations expect to find everything in the metadata, they still need to search through dictionaries.

Parameters:

dictionary : dict or lsst.daf.base.PropertyList

Source for the common keywords.

Raises:

RuntimeError

Raised if the dictionary does not match the expected OBSTYPE.

classmethod determineCalibClass(metadata, message)

Attempt to find calibration class in metadata.

Parameters:

metadata : dict or lsst.daf.base.PropertyList

Metadata possibly containing a calibration class entry.

message : str

Message to include in any errors.

Returns:

calibClass : object

The class to use to read the file contents. Should be an lsst.ip.isr.IsrCalib subclass.

Raises:

ValueError

Raised if the resulting calibClass is the base lsst.ip.isr.IsrClass (which does not implement the content methods).

fromDetector(detector)

Read metadata parameters from a detector.

Parameters:

detector : lsst.afw.cameraGeom.detector

Input detector with parameters to use.

Returns:

calib : lsst.ip.isr.Linearizer

The calibration constructed from the detector.

classmethod fromDict(dictionary)

Construct a calibration from a dictionary of properties.

Parameters:

dictionary : dict

Dictionary of properties.

Returns:

calib : lsst.ip.isr.CalibType

Constructed calibration.

Raises:

RuntimeError

Raised if the supplied dictionary is for a different calibration.

classmethod fromTable(tableList)

Construct calibration from a list of tables.

This method uses the fromDict method to create the calibration, after constructing an appropriate dictionary from the input tables.

Parameters:

tableList : list [lsst.afw.table.Table]

List of tables to use to construct the crosstalk calibration. Two tables are expected in this list, the first containing the per-amplifier CTI parameters, and the second containing the parameters for serial traps.

Returns:

calib : lsst.ip.isr.DeferredChargeCalib

The calibration defined in the tables.

Raises:

ValueError

Raised if the trap type or trap coefficients are not defined properly.

getMetadata()

Retrieve metadata associated with this calibration.

Returns:

meta : lsst.daf.base.PropertyList

Metadata. The returned PropertyList can be modified by the caller and the changes will be written to external files.

classmethod readFits(filename, **kwargs)

Read calibration data from a FITS file.

Parameters:

filename : str

Filename to read data from.

kwargs : dict or collections.abc.Mapping`, optional

Set of key=value pairs to pass to the fromTable method.

Returns:

calib : lsst.ip.isr.IsrCalib

Calibration contained within the file.

classmethod readText(filename, **kwargs)

Read calibration representation from a yaml/ecsv file.

Parameters:

filename : str

Name of the file containing the calibration definition.

kwargs : dict or collections.abc.Mapping`, optional

Set of key=value pairs to pass to the fromDict or fromTable methods.

Returns:

calib : IsrCalibType

Calibration class.

Raises:

RuntimeError

Raised if the filename does not end in “.ecsv” or “.yaml”.

setMetadata(metadata)

Store a copy of the supplied metadata with this calibration.

Parameters:

metadata : lsst.daf.base.PropertyList

Metadata to associate with the calibration. Will be copied and overwrite existing metadata.

toDict()

Return a dictionary containing the calibration properties. The dictionary should be able to be round-tripped through fromDict.

Returns:

dictionary : dict

Dictionary of properties.

toTable()

Construct a list of tables containing the information in this calibration.

The list of tables should create an identical calibration after being passed to this class’s fromTable method.

Returns:

tableList : list [lsst.afw.table.Table]

List of tables containing the crosstalk calibration information. Two tables are generated for this list, the first containing the per-amplifier CTI parameters, and the second containing the parameters for serial traps.

updateMetadata(camera=None, detector=None, filterName=None, setCalibId=False, setCalibInfo=False, setDate=False, **kwargs)

Update metadata keywords with new values.

Parameters:

camera : lsst.afw.cameraGeom.Camera, optional

Reference camera to use to set _instrument field.

detector : lsst.afw.cameraGeom.Detector, optional

Reference detector to use to set _detector* fields.

filterName : str, optional

Filter name to assign to this calibration.

setCalibId : bool, optional

Construct the _calibId field from other fields.

setCalibInfo : bool, optional

Set calibration parameters from metadata.

setDate : bool, optional

Ensure the metadata CALIBDATE fields are set to the current datetime.

kwargs : dict or collections.abc.Mapping, optional

Set of key=value pairs to assign to the metadata.

validate(other=None)

Validate that this calibration is defined and can be used.

Parameters:

other : object, optional

Thing to validate against.

Returns:

valid : bool

Returns true if the calibration is valid and appropriate.

writeFits(filename)

Write calibration data to a FITS file.

Parameters:

filename : str

Filename to write data to.

Returns:

used : str

The name of the file used to write the data.

writeText(filename, format='auto')

Write the calibration data to a text file.

Parameters:

filename : str

Name of the file to write.

format : str

Format to write the file as. Supported values are:

"auto" : Determine filetype from filename. "yaml" : Write as yaml. "ecsv" : Write as ecsv.

Returns:

used : str

The name of the file used to write the data. This may differ from the input if the format is explicitly chosen.

Raises:

RuntimeError

Raised if filename does not end in a known extension, or if all information cannot be written.

Notes

The file is written to YAML/ECSV format and will include any associated metadata.