KeplerQualityFlags

class lightkurve.utils.KeplerQualityFlags

Bases: lightkurve.utils.QualityFlags

This class encodes the meaning of the various Kepler QUALITY bitmask flags, as documented in the Kepler Archive Manual (Ref. [1], Table 2.3).

References

[1]Kepler: A Search for Terrestrial Planets. Kepler Archive Manual. http://archive.stsci.edu/kepler/manuals/archive_manual.pdf

Attributes Summary

ApertureCosmic
Argabrightening
ArgabrighteningOnCCD
AttitudeTweak
CoarsePoint
CollateralCosmic
DEFAULT_BITMASK DEFAULT bitmask identifies all cadences which are definitely useless.
Desat
DetectorAnomaly
EarthPoint
HARDEST_BITMASK HARDEST bitmask identifies cadences with any flag set.
HARD_BITMASK HARD bitmask is conservative and may identify cadences which are useful.
ImpulsiveOutlier
ManualExclude
NoData
NoFinePoint
OPTIONS Dictionary which provides friendly names for the various bitmasks.
PossibleThrusterFiring
RollingBandInAperture
RollingBandInMask
STRINGS Pretty string descriptions for each flag
SafeMode
SensitivityDropout
ThrusterFiring
ZeroCrossing

Methods Summary

create_quality_mask(quality_array[, bitmask]) Returns a boolean array which flags good cadences given a bitmask.
decode(quality) Converts a Kepler QUALITY value into a list of human-readable strings.

Attributes Documentation

ApertureCosmic = 128
Argabrightening = 64
ArgabrighteningOnCCD = 4096
AttitudeTweak = 1
CoarsePoint = 4
CollateralCosmic = 8192
DEFAULT_BITMASK = 1130799

DEFAULT bitmask identifies all cadences which are definitely useless.

Desat = 32
DetectorAnomaly = 16384
EarthPoint = 8
HARDEST_BITMASK = 2096639

HARDEST bitmask identifies cadences with any flag set. Its use is not recommended.

HARD_BITMASK = 1664431

HARD bitmask is conservative and may identify cadences which are useful.

ImpulsiveOutlier = 2048
ManualExclude = 256
NoData = 65536
NoFinePoint = 32768
OPTIONS = {'default': 1130799, 'hard': 1664431, 'hardest': 2096639, 'none': 0}

Dictionary which provides friendly names for the various bitmasks.

PossibleThrusterFiring = 524288
RollingBandInAperture = 131072
RollingBandInMask = 262144
STRINGS = {1: 'Attitude tweak', 2: 'Safe mode', 4: 'Coarse point', 8: 'Earth point', 16: 'Zero crossing', 32: 'Desaturation event', 64: 'Argabrightening', 128: 'Cosmic ray in optimal aperture', 256: 'Manual exclude', 1024: 'Sudden sensitivity dropout', 2048: 'Impulsive outlier', 4096: 'Argabrightening on CCD', 8192: 'Cosmic ray in collateral data', 16384: 'Detector anomaly', 32768: 'No fine point', 65536: 'No data', 131072: 'Rolling band in optimal aperture', 262144: 'Rolling band in full mask', 524288: 'Possible thruster firing', 1048576: 'Thruster firing'}

Pretty string descriptions for each flag

SafeMode = 2
SensitivityDropout = 1024
ThrusterFiring = 1048576
ZeroCrossing = 16

Methods Documentation

classmethod create_quality_mask(quality_array, bitmask=None)

Returns a boolean array which flags good cadences given a bitmask.

This method is used by the constructors of KeplerTargetPixelFile and KeplerLightCurveFile to initialize their quality_mask class attribute which is used to ignore bad-quality data.

Parameters:
quality_array : array of int

‘QUALITY’ column of a Kepler target pixel or lightcurve file.

bitmask : int or str

Bitmask (int) or one of ‘none’, ‘default’, ‘hard’, or ‘hardest’.

Returns:
boolean_mask : array of bool

Boolean array in which True means the data is of good quality.

classmethod decode(quality)

Converts a Kepler QUALITY value into a list of human-readable strings.

This function takes the QUALITY bitstring that can be found for each cadence in Kepler/K2’s pixel and light curve files and converts into a list of human-readable strings explaining the flags raised (if any).

Parameters:
quality : int

Value from the ‘QUALITY’ column of a Kepler/K2 pixel or lightcurve file.

Returns:
flags : list of str

List of human-readable strings giving a short description of the quality flags raised. Returns an empty list if no flags raised.


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