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Coding the JWST Calibration Pipeline(s). 2010 Calibration Workshop Robert Jedrzejewski / STScI. JWST Calibration Pipeline Plan. STScI will develop the calibration pipelines for JWST SI Teams will provide the calibration algorithms to be used in the calibration pipelines
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Coding the JWST Calibration Pipeline(s) 2010 Calibration Workshop Robert Jedrzejewski/STScI
JWST Calibration Pipeline Plan • STScI will develop the calibration pipelines for JWST • SI Teams will provide the calibration algorithms to be used in the calibration pipelines • Experience from developing the HST Calibration Pipelines will help guide the design
HST Calibration Pipelines • CALCOS • CALACS • CALWF3 • CALSTIS /acs/calacs/acsccd acsccd.c blevdrift.c blevfit.c doatod.c dobias.c doblev.c doccd.c doflash.c findblev.c findover.c getacsflag.c getccdsw.c mainccd.c /wf3/calwf3/wf3ccd blevdrift.c blevfit.c doatod.c dobias.c doblev.c doccd.c doflash.c findblev.c findover.c getccdsw.c getflags.c mainccd.c wf3ccd.c /stis/calstis/cs1 blevdrift.c blevfit.c doatod.c dobias.c doblev.c findblev.c findover.c getflags1.c
NIRSpec Multi-Object Spectroscopy Long-slit spectroscopy Integral Field Spectroscopy JWST Observing Modes • JWST has 4 science instruments, each of which can be used in several ways for science • NIRCam • Imaging • Coronography • Grism Spectroscopy • MIRI • Imaging • Coronography • Long-slit Spectroscopy • Integral Field Spectroscopy • FGS-TFI • Imaging • Coronography • Non-redundant Mask Imaging Instruments share several common modes!
Calibration flow • All JWST data is a representation of a celestial scene, as processed by the OTE and instrument to create an image on the detector • The detector turns that image into a digital dataset (imperfectly!) Detector Instrument JWST OTE Celestial Scene Image formedby telescope Image/spectrumformed by instrument Data Photons go this way
Instrument Calibration Imaging Calibration Spectroscopic Calibration Coronographic Calibration Decomposing the Calibration Pipeline Detector Calibration
Detector Calibration • The detector calibration is simplified because we will only have 2 types of detectors on JWST • 15 Hawaii 2RG HgCdTe detectors on NIRCam, NIRSpec, FGS/TFI • 3 Si:Asdetectors on MIRI • The description of the calibration steps will be the same for either detector type • E.g., Both types of detectors have a Reference Pixel Correction step • The best algorithm for doing the correction will often be different for different instruments • It’s unlikely that the Reference Pixel Correction will be the same for Si:Asand HgCdTe detectors • And often the same • The Nonlinearity Correction algorithm may well be the same for all detectors – we’ll see
JWST Calibration Pipelines or Pipeline? caljwst calDetector calNearIRDetector calMidIRDetector cal calInstrument calImaging calSpectroscopy calCoronography
No more CALxxx • Since we will develop the JWST calibration pipelines in parallel, we can share code much more easily • The functionality shared among the instrument pipelines makes it advantageous to design modules that calibrate generic effects, rather than instrument-specific effects • But the overall driver is the BEST calibration – we will not force the calibration steps to be the same for each instrument.
Summing Up • We can take advantage of the fact that JWST instruments share identical detectors to have the calibration pipelines share much of the detector calibration code • We can use the fact that several observing modes are shared by JWST instruments to have the calibration pipelines share significant amounts of instrument calibration code • It makes more sense to think of CALJWST instead of CALSTIS/CALACS/CALNICA/CALWF3/CALCOS • If a pipeline module needs to be different for different instruments, it will be