|
| __init__ (self, **kwargs) |
|
| run (self, exposure, sources, background) |
|
| update_psf_stats (self, summary, psf, bbox, sources=None, image_mask=None, sources_is_astropy=False) |
|
| update_wcs_stats (self, summary, wcs, bbox, visitInfo) |
|
| update_photo_calib_stats (self, summary, photo_calib) |
|
| update_background_stats (self, summary, background) |
|
| update_masked_image_stats (self, summary, masked_image) |
|
| update_effective_time_stats (self, summary, exposure) |
|
Task to compute exposure summary statistics.
This task computes various quantities suitable for DPDD and other
downstream processing at the detector centers, including:
- psfSigma
- psfArea
- psfIxx
- psfIyy
- psfIxy
- ra
- dec
- zenithDistance
- zeroPoint
- skyBg
- skyNoise
- meanVar
- raCorners
- decCorners
- astromOffsetMean
- astromOffsetStd
These additional quantities are computed from the stars in the detector:
- psfStarDeltaE1Median
- psfStarDeltaE2Median
- psfStarDeltaE1Scatter
- psfStarDeltaE2Scatter
- psfStarDeltaSizeMedian
- psfStarDeltaSizeScatter
- psfStarScaledDeltaSizeScatter
These quantities are computed based on the PSF model and image mask
to assess the robustness of the PSF model across a given detector
(against, e.g., extrapolation instability):
- maxDistToNearestPsf
- psfTraceRadiusDelta
These quantities are computed to assess depth:
- effTime
- effTimePsfSigmaScale
- effTimeSkyBgScale
- effTimeZeroPointScale
Definition at line 144 of file computeExposureSummaryStats.py.
lsst.pipe.tasks.computeExposureSummaryStats.ComputeExposureSummaryStatsTask.update_effective_time_stats |
( |
| self, |
|
|
| summary, |
|
|
| exposure ) |
Compute effective exposure time statistics to estimate depth.
The effective exposure time is the equivalent shutter open
time that would be needed under nominal conditions to give the
same signal-to-noise for a point source as what is achieved by
the observation of interest. This metric combines measurements
of the point-spread function, the sky brightness, and the
transparency.
.. _teff_definitions:
The effective exposure time and its subcomponents are defined in [1]_
References
----------
.. [1] Neilsen, E.H., Bernstein, G., Gruendl, R., and Kent, S. (2016).
Limiting Magnitude, \tau, teff, and Image Quality in DES Year 1
https://www.osti.gov/biblio/1250877/
Parameters
----------
summary : `lsst.afw.image.ExposureSummaryStats`
Summary object to update in-place.
exposure : `lsst.afw.image.ExposureF`
Exposure to grab band and exposure time metadata
Definition at line 508 of file computeExposureSummaryStats.py.
lsst.pipe.tasks.computeExposureSummaryStats.ComputeExposureSummaryStatsTask.update_psf_stats |
( |
| self, |
|
|
| summary, |
|
|
| psf, |
|
|
| bbox, |
|
|
| sources = None, |
|
|
| image_mask = None, |
|
|
| sources_is_astropy = False ) |
Compute all summary-statistic fields that depend on the PSF model.
Parameters
----------
summary : `lsst.afw.image.ExposureSummaryStats`
Summary object to update in-place.
psf : `lsst.afw.detection.Psf` or `None`
Point spread function model. If `None`, all fields that depend on
the PSF will be reset (generally to NaN).
bbox : `lsst.geom.Box2I`
Bounding box of the image for which summary stats are being
computed.
sources : `lsst.afw.table.SourceCatalog` or `astropy.table.Table`
Catalog for quantities that are computed from source table columns.
If `None`, these quantities will be reset (generally to NaN).
The type of this table must correspond to the
``sources_is_astropy`` argument.
image_mask : `lsst.afw.image.Mask`, optional
Mask image that may be used to compute distance-to-nearest-star
metrics.
sources_is_astropy : `bool`, optional
Whether ``sources`` is an `astropy.table.Table` instance instead
of an `lsst.afw.table.Catalog` instance. Default is `False` (the
latter).
Definition at line 239 of file computeExposureSummaryStats.py.