SPACE TELESCOPE SCIENCE INSTITUTE Operated for NASA by AURA COS Pipeline Calibration Outline of...

SPACETELESCOPESCIENCEINSTITUTE

Operated for NASA by AURA

COS Pipeline Calibration•Outline of CALCOS•Processing Steps and Keywords•Reference Files•Associations•Reuse of CALSTIS Code•Retain CALSTIS nomenclature and file naming conventions to the extent that it is useful to do so.

COS PIPELINE PDRP. Hodge

December 7, 2000 CALCOS

Space Telescope Science Institute

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Outline of CALCOS

• Calibrate each wavecal file:Calibrate each wavecal file:• Apply the same calibration as for science dataApply the same calibration as for science data• Extract 1-D spectrumExtract 1-D spectrum• Determine offset in dispersion directionDetermine offset in dispersion direction

• If data are in TIMETAG mode:If data are in TIMETAG mode:• If FUV, determine locations and count rates of stim pinsIf FUV, determine locations and count rates of stim pins• Create corrected timetag tableCreate corrected timetag table• Create accum image from timetag tableCreate accum image from timetag table

• Process ACCUM data:Process ACCUM data:• Basic 2-D calibration (unless already done)Basic 2-D calibration (unless already done)• Extract 1-D spectrumExtract 1-D spectrum• Apply wavelength zero point offset from wavecalApply wavelength zero point offset from wavecal




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FUV Reduction ProcessInput FilesInput Files Processing StepProcessing Step Keyword Keyword

SwitchSwitchOutput FileOutput File

_rtg or _raw_rtg or _raw

DQITABDQITAB

Assign data qualityAssign data quality DQICORRDQICORR _ctg or _flt_ctg or _flt

BRFTABBRFTAB Thermal distortion correctionThermal distortion correction TEMPCORRTEMPCORR _ctg or _flt_ctg or _flt

GEOTABGEOTAB Geometric (INL) correctionGeometric (INL) correction GEOCORRGEOCORR _ctg or _flt_ctg or _flt

Livetime correctionLivetime correction LIVECORRLIVECORR _ctg or _flt_ctg or _flt

PFLTFILEPFLTFILE

LFLTFILELFLTFILE

Divide by flat fieldDivide by flat field FLATCORRFLATCORR _ctg or _flt_ctg or _flt




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FUV Reduction Process (cont.)Input FilesInput Files Processing StepProcessing Step Keyword Keyword


Orbital Doppler correctionOrbital Doppler correction DOPPCORRDOPPCORR _ctg or _flt_ctg or _flt

Heliocentric Doppler correctionHeliocentric Doppler correction HELCORRHELCORR _ctg or _flt_ctg or _flt

PHATABPHATAB Filter by pulse height (or verify Filter by pulse height (or verify good pulse height)good pulse height)

PHACORRPHACORR _ctg or _flt_ctg or _flt

BADTTABBADTTAB Filter by timeFilter by time BADTCORRBADTCORR _ctg_ctg

_ctg_ctg Bin timetag into 2-D accum imageBin timetag into 2-D accum image BINCORRBINCORR _flt_flt




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FUV Reduction Process (cont.)Input FilesInput Files Processing StepProcessing Step Keyword SwitchKeyword Switch Output FileOutput File

_flt_flt

XTRACTABXTRACTAB

Extract 1-D spectrumExtract 1-D spectrum X1DCORRX1DCORR _x1d_x1d

_flt_flt Subtract backgroundSubtract background BACKCORRBACKCORR _x1d_x1d

LAMPTABLAMPTAB Correct wavelength zero pointCorrect wavelength zero point WAVECORRWAVECORR _x1d_x1d

_x1d_x1d

DISPTABDISPTAB

Assign wavelengthsAssign wavelengths DISPCORRDISPCORR _x1d_x1d

_x1d_x1d

PHOTTABPHOTTAB

Convert count rate to fluxConvert count rate to flux FLUXCORRFLUXCORR _x1d_x1d

_x1d_x1d Combine FP-split dataCombine FP-split data FPCORRFPCORR _x1s_x1s




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NUV Reduction ProcessInput FilesInput Files Processing StepProcessing Step Keyword Keyword


_rtg or _raw_rtg or _raw

DQITABDQITAB

Assign data qualityAssign data quality DQICORRDQICORR _ctg or _flt_ctg or _flt

Livetime correctionLivetime correction LIVECORRLIVECORR _ctg or _flt_ctg or _flt

PFLTFILEPFLTFILE

LFLTFILELFLTFILE

Divide by flat fieldDivide by flat field FLATCORRFLATCORR _ctg or _flt_ctg or _flt

Orbital Doppler correctionOrbital Doppler correction DOPPCORRDOPPCORR _ctg or _flt_ctg or _flt

Heliocentric Doppler correctionHeliocentric Doppler correction HELCORRHELCORR _ctg or _flt_ctg or _flt




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NUV Reduction Process (cont.)Input FilesInput Files Processing StepProcessing Step

BADTTABBADTTAB Filter by timeFilter by time BADTCORRBADTCORR _ctg_ctg

_ctg_ctg Bin timetag into 2-D accum imageBin timetag into 2-D accum image BINCORRBINCORR _flt_flt

_flt_flt

XTRACTABXTRACTAB

Extract 1-D spectrumExtract 1-D spectrum X1DCORRX1DCORR _x1d_x1d

_flt_flt Subtract backgroundSubtract background BACKCORRBACKCORR _x1d_x1d

LAMPTABLAMPTAB Correct wavelength zero pointCorrect wavelength zero point WAVECORRWAVECORR _x1d_x1d

_x1d_x1d

DISPTABDISPTAB

Assign wavelengthsAssign wavelengths DISPCORRDISPCORR _x1d_x1d

_x1d_x1d

PHOTTABPHOTTAB

Convert count rate to fluxConvert count rate to flux FLUXCORRFLUXCORR _x1d_x1d




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Reference ImagesTable NameTable Name SuffixSuffix DescriptionDescription Selection CriteriaSelection Criteria

PFLTFILEPFLTFILE pflpfl Pixel-to-pixel flat fieldPixel-to-pixel flat field DETECTORDETECTOR

LFLTFILELFLTFILE lfllfl Low-order flat fieldLow-order flat field DETECTORDETECTOR




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Reference TablesTable nameTable name SuffixSuffix DescriptionDescription Selection Selection

keywordskeywordsSelection Selection columnscolumns

Parameter Parameter columnscolumns

DQITABDQITAB bpxbpx Locations of bad Locations of bad pixelspixels

DETECTORDETECTOR SEGMENTSEGMENT lx, ly,lx, ly,

dx, dy, q, dx, dy, q, typetype

BADTTABBADTTAB timtim Bad time intervalsBad time intervals start, stopstart, stop

BRFTABBRFTAB brfbrf Baseline reference Baseline reference frame parametersframe parameters

DETECTORDETECTOR SEGMENTSEGMENT sx1, sy1,sx1, sy1,

sx2, sy2sx2, sy2

PHATABPHATAB phapha Pulse height Pulse height thresholdsthresholds

DETECTORDETECTOR SEGMENTSEGMENT llt, ultllt, ult




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Reference Tables (cont.)Table nameTable name SuffixSuffix DescriptionDescription Selection Selection



GEOTABGEOTAB geogeo Geometric (INL) Geometric (INL) correctioncorrection

DETECTORDETECTOR SEGMENTSEGMENT xnelem, xnelem, xdispl*, xdispl*, ynelem, ynelem, ydispl*ydispl*

XTRACTABXTRACTAB 1dx1dx Locations of spectra Locations of spectra and background and background regionsregions

DETECTORDETECTOR SEGMENT, SEGMENT, OPT_ELEM, OPT_ELEM, CENWAVECENWAVE

slope, slope, b_spec,b_spec,

(or b_a,(or b_a,

b_b, b_c), b_b, b_c), bkg1, bkg2, bkg1, bkg2, height, height, bheight, bheight, bwidthbwidth




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Reference Tables (cont.)Table nameTable name SuffixSuffix DescriptionDescription Selection Selection



LAMPTABLAMPTAB lmplmp Template lamp Template lamp spectrumspectrum

nelem, nelem, wavelength*, wavelength*, flux*flux*

DISPTABDISPTAB dspdsp Dispersion Dispersion coefficientscoefficients

DETECTORDETECTOR SEGMENT,SEGMENT,OPT_ELEM,OPT_ELEM,CENWAVECENWAVE

ncoeff,ncoeff,

coeff*coeff*

PHOTTABPHOTTAB phtpht Photometric Photometric throughputthroughput

DETECTORDETECTOR SEGMENT,SEGMENT,APERTURE,APERTURE,OPT_ELEM,OPT_ELEM,CENWAVECENWAVE

nelem, nelem, wavelength*, wavelength*, throughput*throughput*




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Associations• CALCOS uses the association table to identify files that will be used in calibrationCALCOS uses the association table to identify files that will be used in calibration

• Contents of an association:Contents of an association:• science datascience data• wavecal datawavecal data

• Science data:Science data:• timetagtimetag• accum:accum:

• spectrumspectrum• stim-pulse data (FUV)stim-pulse data (FUV)• pulse-height data (FUV)pulse-height data (FUV)

• both FUV segments in the same fileboth FUV segments in the same file• FP-split or repeatobs in separate filesFP-split or repeatobs in separate files




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Reuse of CALSTIS Code• Algorithm reuse, more than code reuse:Algorithm reuse, more than code reuse:

• Estimate of code reuse: 5%Estimate of code reuse: 5%• Estimate of algorithm reuse: 30%Estimate of algorithm reuse: 30%

• Differences that affect the code but not necessarily the algorithm:Differences that affect the code but not necessarily the algorithm:• Wavecal observations will be handled differentlyWavecal observations will be handled differently• Different zero point for on-board Doppler shift (affects convolution of flat fields)Different zero point for on-board Doppler shift (affects convolution of flat fields)• NUV spectra arranged differently on detectorNUV spectra arranged differently on detector

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