The Awe photometric pipeline

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The Awe photometric pipeline

• Software implementation

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Photometric pipeline class model
Cal569
Cal565
Cal563/Cal564
Cal562
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Photometric pipeline equation to solve
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Photometric pipeline source catalogs
PhotSrcCatalog association between standard
star catalog and
Sextractor catalog
photsrccat.refcat PhotRefCatalog() photsrccat.fr
ame ScienceFrame() photsrccat.transform
PhotTransformation() photsrccat.make()
rawzero photsrccat.photsourcelist3.get_raw_zer
opoint() rawzero_list photsrccat.get_list_of
_raw_zeropoints()
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Photometric pipeline color terms
Color terms are dealt with in photsrccatalog.make(
)
photsrccatalog.transform PhotTransformation()
transf.get_dict_of_transformed_magnitudes(mag_id,
refcat)
? the mag_id is the primary key through which the
system identifies the photometric band
Examples JohnsonV, CousinsR, SloanU, SloanG
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Photometric pipeline extinction
Atmospheric extinction is treated as a pluggable
algorithm ? three different algorithms
implemented at present
atmospheric_extinction AtmosphericExtinctionFram
es() atmospheric_extinction.polar
photsrccat_list_1 atmospheric_extinction.equat
photsrccat_list_2 atmospheric_extinction.extcurve
PhotExtinctionCurve() atmospheric_extinction.mak
e()
? system easily extended with new ways to derive
the atmospheric extinction
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Photometric pipeline zeropoints
The zeropoints are derived by and contained
within a PhotometricParameters object.
photometricparameters.photcat
photsrccatalog photometricparameters.extinct
atmospheric_extinction photometricparameters.make(
)
? a PhotometricParameters object represents the
Calfile that is used in the image pipeline
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Photometric pipeline illumination correction

• software has to be implemented
• current scheme is to apply the correction on
  frame level in the image pipeline
• the input frames for the photometric pipeline
  are, therefore, already corrected for this effect

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Photometric pipeline a general recipe
photsrccatalog.refcat PhotRefCatalog() photsrcca
talog.frame ScienceFrame() photsrccatalog.transf
orm PhotTransformation()
photsrccatalog.make()
atmospheric_extinction BaseAtmosphericExtinction
() atmospheric_extinction.make()
photometricparameters.extinct
atmospheric_extinction photometricparameters.photc
at photsrccatalog photometricparameters.make()
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Photometric pipeline a use case (1)
Available resources for (rough) photometric
calibration
during the night, for every filter only ONE
observation was made of a standard field
standard stars are present on only ONE of the
chips of the N-chip camera
a standard extinction curve has to be used
no illumination correction is known, nor can it
be derived
Conclusion the prospects are bleak
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Photometric pipeline a use case (2)
the_photsrccatalog.refcat PhotRefCatalog() the_p
hotsrccatalog.frame ScienceFrame() the_photsrcca
talog.transform PhotTransformation() the_photsrc
catalog.make()
?
photsrccatalog.frame ScienceFrame() photsrccatal
og.set_sky_background()
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Photometric pipeline a use case (3)
atmos_extinction AtmosphericExtinctionCurve() at
mos_extinction.filter scienceframe.filter atmos_
extinction.extcurve PhotExtinctionCurve() atmos_
extinction.report PhotometricExtinctionReport()
atmos_extinction.make()
? Note the dependency on a Filter object ? Note
the dependency on a PhotometricExtinctionReport
object
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Photometric pipeline a use case (4)
the_photometricparameters PhotometricParameters(
) the_photometricparameters.photcat
the_photsrccatalog the_photometricparameters.extin
ct atmos_extinction the_photometricparameters.ma
ke()
?
photometricparameters.photcat
photsrccatalog photometricparameters.extinct
atmos_extinction photometricparameters.set_zeropoi
nt(zp, zp_err)
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Photometric pipeline resources

• /cvsroot/catalog/
• /cvsroot/opipe/Toolbox/photometry
• /cvsroot/opipe/docs
• /cvsroot/opipe/astro/main

• Yours truly (ronald_at_astro.rug.nl)