PhotonTransferCurveExtractTask¶
PhotonTransferCurveExtractTask constructs a photon transfer curve (PTC) dataset from a single pair of flat field exposures.
Processing summary¶
PhotonTransferCurveExtractTask runs these operations:
Pairs exposures together by either exposure time (the default) or by exposure id (in the case where the exposure time does not track with the observed flux).
Measures the mean, variances, and covariances from the difference of the pair of exposures.
Persists these results in a set of partial PTC datasets.
Python API summary¶
from lsst.cp.pipe.ptc.cpPtcExtract import PhotonTransferCurveExtractTask
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class
PhotonTransferCurveExtractTask(*, config=None, log=None, initInputs=None, **kwargs) Task to measure covariances from flat fields
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- attributeconfig
Access configuration fields and retargetable subtasks.
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method
run(inputExp, inputDims, taskMetadata=None, inputPhotodiodeData=None) Measure covariances from difference of flat pairs
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See also
See the PhotonTransferCurveExtractTask API reference for complete details.
Retargetable subtasks¶
No subtasks.
Configuration fields¶
auxiliaryHeaderKeys¶
Auxiliary header keys to store with the PTC dataset.
binSize¶
Bin the image by this factor in both dimensions.
connections¶
- Data type
lsst.pipe.base.config.PhotonTransferCurveExtractConfigConnections- Field type
Configurations describing the connections of the PipelineTask to datatypes
detectorMeasurementRegion¶
- Default
'AMP'- Field type
strChoiceField(optional)- Choices
'AMP'Amplifier of the detector.
'FULL'Full image.
NoneField is optional
Region of each exposure where to perform the calculations (amplifier or full image).
doExtractPhotodiodeData¶
Extract photodiode data?
doGain¶
Calculate a gain per input flat pair.
edgeMaskLevel¶
- Default
'DETECTOR'- Field type
strChoiceField(optional)- Choices
'DETECTOR'Mask only the edges of the full detector.
'AMP'Mask edges of each amplifier.
NoneField is optional
Mask edge pixels in which coordinate frame: DETECTOR or AMP?
efdPhotodiodeSeries¶
EFD series to use to get photodiode values.
efdSalIndex¶
EFD SAL Index to select electrometer. This is 101 for mainTel, 201 for auxTel.
gainCorrectionType¶
- Default
'FULL'- Field type
strChoiceField(optional)- Choices
'NONE'No correction.
'SIMPLE'First order correction.
'FULL'Second order correction.
NoneField is optional
Correction type for the gain.
ksHistLimitMultiplier¶
Number of sigma (as predicted from the mean value) to compute KS test histogram.
ksHistMinDataValues¶
Minimum number of good data values to compute KS test histogram.
ksHistNBins¶
Number of bins for the KS test histogram.
maskNameList¶
Mask list to exclude from statistics calculations.
matchExposuresByFluxKeyword¶
Header keyword for flux if matchExposuresType is FLUX.
matchExposuresType¶
- Default
'TIME'- Field type
strChoiceField(optional)- Choices
'TIME'Match exposures by exposure time.
'FLUX'Match exposures by target flux. Use header keyword in matchExposuresByFluxKeyword to find the flux.
'EXPID'Match exposures by exposure ID.
NoneField is optional
Match input exposures by time, flux, or expId
maxMeanSignal¶
Maximum values (inclusive) of mean signal (in ADU) below which to consider, per amp. The same cut is applied to all amps if this dictionary is of the form {‘ALL_AMPS’: value} Deprecated: This config has been moved to cpSolvePtcTask, and will be removed after v26.
maximumRangeCovariancesAstier¶
Maximum range of covariances as in Astier+19
minMeanSignal¶
Minimum values (inclusive) of mean signal (in ADU) per amp to use. The same cut is applied to all amps if this parameter [dict] is passed as {‘ALL_AMPS’: value} Deprecated: This config has been moved to cpSolvePtcTask, and will be removed after v26.
minNumberGoodPixelsForCovariance¶
Minimum number of acceptable good pixels per amp to calculate the covariances (via FFT or direclty).
nIterSigmaClipPtc¶
Number of sigma-clipping iterations for afwMath.StatisticsControl()
nSigmaClipPtc¶
Sigma cut for afwMath.StatisticsControl()
numEdgeSuspect¶
Number of edge pixels to be flagged as untrustworthy.
photodiodeCurrentScale¶
Scale factor to apply to photodiode current values for the CHARGE_SUM integration method.
photodiodeIntegrationMethod¶
- Default
'CHARGE_SUM'- Field type
strChoiceField(optional)- Choices
'DIRECT_SUM'Use numpy’s trapz integrator on all photodiode readout entries
'TRIMMED_SUM'Use numpy’s trapz integrator, clipping the leading and trailing entries, which are nominally at zero baseline level.
'CHARGE_SUM'Treat the current values as integrated charge over the sampling interval and simply sum the values, after subtracting a baseline level.
NoneField is optional
Integration method for photodiode monitoring data.
saveLogOutput¶
Flag to enable/disable saving of log output for a task, enabled by default.
thresholdDiffAfwVarVsCov00¶
If the absolute fractional differece between afwMath.VARIANCECLIP and Cov00 for a region of a difference image is greater than this threshold (percentage), a warning will be issued.
useEfdPhotodiodeData¶
Extract photodiode values from EFD?