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.cpExtractPtcTask import PhotonTransferCurveExtractTask
-
class
PhotonTransferCurveExtractTask(*, config=None, log=None, initInputs=None, **kwargs) Task to measure covariances from flat fields
...
- attributeconfig
Access configuration fields and retargetable subtasks.
See also
See the PhotonTransferCurveExtractTask API reference for complete details.
Retargetable subtasks¶
No subtasks.
Configuration fields¶
binSize¶
Bin the image by this factor in both dimensions.
connections¶
- Data type
lsst.pipe.base.config.Connections- 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).
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?
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.
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}
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}
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.
saveLogOutput¶
Flag to enable/disable saving of log output for a task, enabled by default.
saveMetadata¶
Flag to enable/disable metadata saving 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.