31.7 Post-Calibration Output Files

Output Calibrated FOS Data Files

Filename Extension	File Contents
.c0h and .c0d	Calibrated wavelengths
.c1h and .c1d	Calibrated fluxes
.c2h and .c2d	Calibrated statistical error
.c3h and .c3d	Special mode data
.cqh and .cqd	Calibrated data quality
.c4h and .c4d	Count rate object and sky spectra
.c5h and .c5d	Flatfielded object count rate spectrum
.c6h and .c6d	Flatfielded sky count rate spectrum
.c7h and .c7d	Background count rate spectrum
.c8h and .c8d	Flatfielded and sky subtracted object count rate spectrum

If the reference files and reference tables used in the pipeline processing do not reflect the actual instrument performance, calibration errors can occur, which can lead to artificial features in the calibrated science data. In the next chapter, we address a variety of sources of error in FOS calibration and assess limiting accuracies in the STScI instrument calibration.

Figure 31.9: Partial Sample Post-COSTAR FOS .c1h Header

GCOUNT  =                   77 /

        / FOS DATA DESCRIPTOR KEYWORDS

INSTRUME= 'FOS               ' / instrument in use

ROOTNAME= 'Y3JK0709T         ' / rootname of the observation set

FILETYPE= 'FLX     '           / file type

BUNIT   = 'ERGS/CM**2/S/A'     / brightness units

        / CALIBRATION FLAGS AND INDICATORS

GRNDMODE= 'RAPID-READOUT     ' / ground software mode

DETECTOR= 'BLUE              ' / detector in use: amber, blue

APER_ID = 'B-2               ' / aperture id

POLAR_ID= 'C                 ' / polarizer id

POLANG  =                  0.0 / initial angular position of polarizer

FGWA_ID = 'H13               ' / FGWA id

FCHNL   =                    0 / first channel

NCHNLS  =                  512 / number of channels

OVERSCAN=                    5 / overscan number

NXSTEPS =                    4 / number of x steps

YFGIMPEN=                    T / onboard GIMP correction enabled (T/F)

YFGIMPER= 'NO                ' / error in onboard GIMP correction (YES/NO)

        / CALIBRATION REFERENCE FILES AND TABLES

DEFDDTBL=                    F / UDL disabled diode table used

BACHFILE= 'yref$b3m1128my.r0h' / background reference header file

FL1HFILE= 'yref$e7813577y.r1h' / first flat-field header file

FL2HFILE= 'N/A               ' / second flat-field header file

IV1HFILE= 'yref$e3h14503y.r2h' / first inverse sensitivity header file

IV2HFILE= 'N/A               ' / second inverse sensitivity header file

AISHFILE= 'yref$fac08361y.r8h' / average inverse sensitivity header file

RETHFILE= 'N/A               ' / waveplate retardation header file

DDTHFILE= 'yref$d9h1244ay.r4h' / disabled diode table header file

DQ1HFILE= 'yref$b2f1306ry.r5h' / first data quality initialization header file

DQ2HFILE= 'N/A               ' / second data quality initialization header file

CCG2    = 'mtab$a3d1145ly.cmg' / paired pulse correction parameters table

CCS0    = 'ytab$a3d1145dy.cy0' / aperture parameters

CCS1    = 'ytab$aaj0732ay.cy1' / aperture position parameters

CCS2    = 'ytab$a3d1145fy.cy2' / sky emission line regions

CCS3    = 'ytab$a3d1145gy.cy3' / bkg and sky filter widths

CCS4    = 'ytab$e5v13262y.cy4' / polarimetry parameters

CCS5    = 'ytab$a3d1145jy.cy5' / sky shifts

CCS6    = 'ytab$e5v11576y.cy6' / wavelength coefficients

CCS7    = 'ytab$ba910502y.cy7' / GIMP correction scale factors

CCS8    = 'ytab$ba31407ly.cy8' / predicted background count rates

CCS9    = 'ytab$e3i09491y.cy9' / scattered light parameters

CCSA    = 'ytab$fad1554cy.cya' / OTA focus history

CCSB    = 'ytab$g1512585y.cyb' / relative aperture throughput coeff

CCSC    = 'ytab$fad1554hy.cyc' / aperture throughput vs OTA focus

CCSD    = 'ytab$fad1554ky.cyd' / time changes in sensitivity

        / CALIBRATION SWITCHES

CNT_CORR= 'COMPLETE'           / count to count rate conversion

OFF_CORR= 'OMIT              ' / GIMP correction

PPC_CORR= 'COMPLETE'           / paired pulse correction

BAC_CORR= 'COMPLETE'           / background subtraction

GMF_CORR= 'COMPLETE'           / scale reference background

SCT_CORR= 'COMPLETE'           / scattered light correction

FLT_CORR= 'COMPLETE'           / flat fielding

SKY_CORR= 'SKIPPED '           / sky subtraction

WAV_CORR= 'COMPLETE'           / wavelength scale generation

FLX_CORR= 'OMIT              ' / flux scale generation

APR_CORR= 'COMPLETE'           / aperture throughput corrections

AIS_CORR= 'COMPLETE'           / AIS flux scale generation

TIM_CORR= 'COMPLETE'           / time changes in sensitivity correction

ERR_CORR= 'COMPLETE'           / propagated error computation

MOD_CORR= 'PERFORM           ' / ground software mode dependent reductions

HISTORY   FL1HFILE=yref$e7813577y.r1h       FLT_CORR=COMPLETE

HISTORY   INFLIGHT  01/03/1994

HISTORY   Based on SMOV Superflats: proposal 4776

HISTORY   AISHFILE=yref$fac08361y.r8h       AIS_CORR=COMPLETE

HISTORY   INFLIGHT 01/02/1994 - 15/07/1995

HISTORY   1st delivery: post-costar ais time+aperture dependent flux cal

END