The main header, or HDU1, typically contains most of the information about
the file, while the headers for the extensions usually give
additional information about the data in each extension. The main headers are
parsed into sections, and all science data files (RAW, CAL, IDF, ALL, ANO, and NVO)
contain the same sections. However, for the RAW images, not all
of the fields are populated. Several of the ancillary files
contain similar information. The following sections describe these
standard header sections.
This chapter contains general information useful to the "Advanced" and "Intermediate" user. Its contents are not, however, of immediate relevance to the "Casual" user.
DATA DESCRIPTION KEYWORDS: This set of keywords is fairly self-explanatory. For exposure level files, OBS_STAT is replaced with EXP_STAT.
DATA DESCRIPTION KEYWORDS TELESCOP= 'FUSE ' / Telescope used to acquire data INSTRUME= 'FUV ' / Instrument in use (one of FUV, FESA, or FESB) ROOTNAME= 'A1330147002 ' / Rootname of the observation set (ppppttooeee) FILENAME= 'A13301470021bsic4ttagfcal.fit' / Name of file FILETYPE= 'CALIBRATED EXTRACTED SPECTRUM' / Type of data found in data file EXP_STAT= 0 / Science data processing status (0=good)
PROPOSAL INFORMATION: This section is populated from the Mission Planning Database (MPDB).
PROPOSAL INFORMATION PRGRM_ID= 'A133 ' / Program ID from data header TARG_ID = '01 ' / Target ID from data header SCOBS_ID= '47 ' / Observation ID from data header EXP_ID = '002 ' / Exposure ID from data header OBS_ID = '47 ' / Observation ID from proposal database PR_INV_L= 'Fullerton ' / Last name of principal investigator PR_INV_F= 'Alex ' / First name of principal investigator
TARGET INFORMATION: These keywords are also populated from the MPDB and are not measured quantities. The expected fluxes and count rates come from the Phase 2 Proposal form submitted by the observer. A key to the numerical Object Classes are given in Section 8.4.5.
TARGET INFORMATION TARGNAME= 'SK-67D166 ' / Target name on proposal RA_TARG = 82.934625 / [deg] Right ascension of the target (J2000) DEC_TARG= -67.6335 / [deg] Declination of the target (J2000) APER_PA = 23.518158 / [deg] Position angle of Y axis (E of N) EQUINOX = 2000.0 / Equinox of celestial coordinate system ELAT = -8.705045834317E+01 / [deg] Ecliptic latitude ELONG = 3.354528613035E+02 / [deg] Ecliptic longitude GLAT = -3.248583704098E+01 / [deg] Galactic latitude GLONG = 2.778388799536E+02 / [deg] Galactic longitude OBJCLASS= 13 / Object class (modified IUE classification) SP_TYPE = 'O4If+ ' / MK spectral type and luminosity class (or other SRC_TYPE= 'PC ' / [P]oint or [E]xtended, [C]ontinuum, [E]mission VMAG = 12.27 / Target V magnitude EBV = 0.1 / Color excess E(B-V) Z = 0.0 / Redshift EFLX_950= 1.9E-12 / Expected flux at 950 A EFLX1050= 2.7E-12 / Expected flux at 1050 A EFLX1150= 2.6E-12 / Expected flux at 1150 A HIGH_PM = 'F ' / High proper motion target (T or F) MOV_TARG= 'F ' / [F]ixed or [M]oving target PCNTRATE= 1592.9 / Expected count rate (sum of all channels)
SUMMARY EXPOSURE INFORMATION: This section contains the date and time of the observation, including the exposure start and end time, and the computed exposure time. Exposure start and end times are expressed in Modified Julian Date (MJD = JD-2400000.5). The EXPENDC keyword indicates the reason for the termination of the exposure - entry into South Atlantic Anomaly (SAA), occultation (OCC), end of night (NGHT), or the natural end of exposure (ENDE) or end of observation (ENDO). The Sun and Moon angles, and the minimum pointing angle above the Earth limb are computed by the calibration software, and are therefore 0 in the raw data files. For TTAG data, the calibration software also screens photon address data, and ignores bad data taken in, for instance, the SAA. There are a number of keywords reporting the actions taken by this screening step, and are shown below. The meanings of these codes are summarized in Table 4.10, 4.11, and 4.12 of Section 22.214.171.124. If data are screened out, then EXPTIME will be smaller than RAWTIME in the IDF and the calibrated files.
SUMMARY EXPOSURE INFORMATION DATEOBS = '2000-10-12' / UT date of start of exposure (yyyy-mm-dd) TIMEOBS = '14:38:30' / UT start time of exposure (hh:mm:ss) EXPSTART= 5.182961006944E+04 / Exposure start time (Modified Julian Date) EXPEND = 5.182962262750E+04 / Exposure end time (Modified Julian Date) EXPTIME = 1085. / [s] Total time after screening EXPENDC = 'ENDO ' / End condition (ENDO; SAA; OCC; NGHT; ENDE) NEVENTS = 421399 / Number of events in raw data file RAWTIME = 1.085015625000E+03 / [s] Exposure duration of raw data file PLANTIME= 1020 / [s] Planned exposure time SUNANGLE= 92.1169468703347 / [deg] Angle between sun and Z axis MOONANGL= 83.0809764100487 / [deg] Angle between moon and Z axis POLEANGL= 160.545069830942 / [deg] Angle between orbit pole and Z axis GEO_LONG= 164.355774107397 / [deg] Geocentric longitude GEO_LAT = 24.3003425210518 / [deg] Geocentric latitude MAG_LAT = 30.5899872994262 / [deg] Geomagnetic latitude MIN_LIMB= 11.9518247749345 / [deg] Minimum angle above Earth limb NBADEVNT= 10910 / Number of events deleted in screening NBADPHA = 919 / Number of events deleted in PHA screening EXP_BAD = 0 / [s] Time lost to screening EXP_BRST= 0 / [s] Time lost to event bursts EXP_HV = 0 / [s] Time lost to low voltage/FIFO overflow EXP_JITR= 0 / [s] Time lost to jitter EXP_LIM = 0 / [s] Time with low limb angle EXP_SAA = 0 / [s] Time while in SAA EXPNIGHT= 1085 / [s] Night time after screening V_GEOCEN= 2.38573645263126 / [km/s] Observed to geocentric velocity V_HELIO = -1.08708418297615 / [km/s] Geocentric to heliocentric velocity V_LSRDYN= -12.7521820068359 / [km/s] Heliocentric to dynamical LSR V_LSRSTD= -15.775110244751 / [km/s] Heliocentric to standard solar LSR Geocentric and helocentric conversions are applied by the CALFUSE calibration pipeline. LSR conversion is not.
SCIENCE INSTRUMENT CONFIGURATION: These keywords contain planned as well as telemetered values for the instrument configuration. Most of the keywords shown below are self-explanatory. For the detector mask, DET_MASK, AIC1 is an open mask, i.e., none of the photon events are masked out. The focal plane assembly (FPA) X and Z positions from the telemetry are recorded in the header keywords. Note that the FES_FILT keyword is always set to CLR. The mirror focus MIR*FOC keywords are populated only for bright object defocus test exposures.
SCIENCE INSTRUMENT CONFIGURATION INSTMODE= 'TTAG ' / Instrument mode (TTAG or HIST) DETECTOR= '1B ' / Detector for data in this file (1A, 1B, 2A, 2B) APERTURE= 'LWRS ' / Planned target aperture: HIRS, MDRS, LWRS, RFPT BRIT_OBJ= 'NO ' / Special configuration for bright-object obs APER_ACT= 'LWRS_SIC' / Extracted aperture in this file DET_MASK= 'AIC1 ' / Detector mask used NUM_APS = 1 / Number of apertures in use in the observation INITBINX= 1 / Initial binning in X coordinate INITBINY= 1 / Initial binning in Y coordinate SPECBINX= 1 / Current binning in X coordinate SPECBINY= 1 / Current binning in Y coordinate SIA_TBL = ' ' / SIA Table name NUM_HIST= 0 / Number of histograms in the observation INT_CAL = ' ' / Internal Calibration (STIM, NONE) FPSPLIT = 0 / Number of FP Split positions FPASXPOS= 140.145 / [microns] FPA SiC X position FPALXPOS= 116.107 / [microns] FPA LiF X position FPASZPOS= -98.9776 / [microns] FPA SiC Z position FPALZPOS= -34.4119 / [microns] FPA LiF Z position MIRL1FOC= 0.000000 / [microns] LiF 1 mirror position MIRL2FOC= 0.000000 / [microns] LiF 2 mirror position MIRS1FOC= 0.000000 / [microns] SiC 1 mirror position MIRS2FOC= 0.000000 / [microns] SiC 2 mirror position TTPERIOD= 1.0 / [s] Time marker insertion period ENGSNAPT= 300 / [s] Engineering snapshot period TACQSEQ = 'ACQ-T-NOPKUP ' / Target acquisition sequence ROLLOFF = 0.0 / [Deg] Roll offset FES_BIN = 1 / FES binning factor (1;2;4;8) FES_FILT= 'CLR ' / FES filter wheel position: CLR=Clear, COL=Color FES_TPOS= 'OUT ' / FES target position: IN or OUT
DETECTOR HV BIAS RANGES: These keywords list the minimum and maximum high voltage level for all segments during the exposure. The minimum and maximum for a given segment should normally be the same. The nominal high voltage levels were adjusted periodically during the mission; see Table 7.4.
DETECTOR HV BIAS RANGES DET1HVAL= 128 / Det1 MCP A HV bias minimum setting DET1HVAH= 128 / Det1 MCP A HV bias maximum setting DET1HVBL= 128 / Det1 MCP B HV bias minimum setting DET1HVBH= 128 / Det1 MCP B HV bias maximum setting DET2HVAL= 128 / Det2 MCP A HV bias minimum setting DET2HVAH= 128 / Det2 MCP A HV bias maximum setting DET2HVBL= 101 / Det2 MCP B HV bias minimum setting DET2HVBH= 101 / Det2 MCP B HV bias maximum setting HV_FLAG = 4 / Detector voltage full throughout exposure
ORBITAL EPHEMERIS: These keywords contain the Keplerian elements for the FUSE orbital ephemeris. Together with the time of observation, these values can be used to calculate where the satellite was in its orbit (although much of this information is already in the timeline table in the IDF files). The calibration software, for instance, uses these values to compute the Doppler correction to apply as it produces the calibrated data.
ORBITAL EPHEMERIS EPCHTIMD= 51829. / Epoch time of parameters whole day (MJD) EPCHTIMF= 0.943173899999238 / Epoch time of parameters fraction of day (MJD) INCLINAT= 24.9842 / [deg] Inclination ECCENTRY= 0.0011377 / Eccentricity MEANANOM= 238.2636 / [deg] Mean anomaly ARGPERIG= 121.8967 / [deg] Argument of perigee RASCASCN= 301.572 / [deg] RA of ascending node SEMIMAJR= 7137.84084370588 / [km] Semi-major axis MEANMOTN= 14.39635355 / [revs/day] Mean motion FDM2COEF= 9.37E-06 / First time derivative of mean motion / 2 SDM6COEF= 0. / Second time derivative of mean motion / 6 DRAGCOEF= 0.00023849 / B star drag coefficient PROPMODL= 'SGP4 ' / Propagation model
SCIENCE DATA PROCESSING STEPS: These keywords indicate which steps of the calibration pipeline have been applied to the data. All processing steps are set to a value of INITIAL in the raw data files. The first pipeline module sets them to either PERFORM or OMIT, depending on whether the corresponding calibration step is to be performed or not. Once a step is completed, its keyword is changed to a value of COMPLETE. If a pipeline module decides not to perform a step labeled PERFORM, it changes the keyword to SKIPPED. Thus, COMPLETE, OMIT, and SKIPPED are all valid keywords in extracted spectral files (see Dixon et al. (2007)).
SCIENCE DATA PROCESSING STEPS INIT_COR= 'COMPLETE' / Initialize processing DIGI_COR= 'COMPLETE' / Check digitizer values ELEC_COR= 'COMPLETE' / Detector dead-time correction IDS__COR= 'COMPLETE' / IDS dead-time correction FIFO_COR= 'COMPLETE' / FIFO overflow correction DEAD_COR= 'COMPLETE' / Apply all dead-time corrections THRM_COR= 'COMPLETE' / Thermal distortion correction RATE_COR= 'COMPLETE' / Count-rate Y distortion TMXY_COR= 'COMPLETE' / Temporal X and Y corrections GEOM_COR= 'COMPLETE' / Geometric distortion PHAH_COR= 'OMIT ' / Assign pulse heights to HIST data PHAX_COR= 'COMPLETE' / Low pulse-height X distortion (walk) ACTV_COR= 'COMPLETE' / Define detector active region LIMB_COR= 'COMPLETE' / Limb-angle screening SAA__COR= 'COMPLETE' / SAA screening VOLT_COR= 'COMPLETE' / Confirm detector voltage BRST_COR= 'COMPLETE' / Screen for bursts APER_COR= 'COMPLETE' / Screen for target out of aperture UGTI_COR= 'COMPLETE' / Set user good-time intervals FLAG_COR= 'COMPLETE' / Set individual photon flags GTI__COR= 'COMPLETE' / Determine good-time intervals TIME_COR= 'OMIT ' / Modify photon arrival times (HIST only) AIRG_COR= 'COMPLETE' / Flag events in airglow regions BPIX_COR= 'COMPLETE' / Flag events in bad-pixel regions PHA__COR= 'COMPLETE' / Pulse-height screening FIND_COR= 'COMPLETE' / Find spectra on detector YMOT_COR= 'COMPLETE' / Track motion of Y centroid GRAT_COR= 'COMPLETE' / Grating motion correction FPA__COR= 'COMPLETE' / FPA offset correction MIRR_COR= 'COMPLETE' / Mirror motion correction JITR_COR= 'COMPLETE' / Satellite jitter correction YCNT_COR= 'COMPLETE' / Y centroid of corrected data CHID_COR= 'COMPLETE' / Final channel assignment TCRT_COR= 'COMPLETE' / Calculate target count rate ASTG_COR= 'COMPLETE' / Astigmatism correction WAVE_COR= 'COMPLETE' / Assign wavelength to photons DOPP_COR= 'COMPLETE' / Heliocentric reference frame FLAT_COR= 'OMIT ' / Flat-field correction FLUX_COR= 'COMPLETE' / Flux-calibrate each photon COMB_COR= 'PERFORM ' / Generate observation-level spectrum
SCIENCE DATA PROCESSING CALIBRATION FILES: These keywords indicate the names of the SDP calibration files and the ancillary files used by the calibration software. Knowing these filenames is important if one is considering reprocessing the data. Since no flat field or worm corrections were applied to the data these fields always remain empty.
SCIENCE DATA PROCESSING CALIBRATION FILES AEFF1CAL= 'aeff1b103.fit ' / Effective-area curve #1 AEFF2CAL= 'aeff1b104.fit ' / Effective-area curve #2 AIRG_CAL= 'airg1b004.fit ' / Geocoronal line locations ASTG_CAL= 'astg1b011.fit ' / Astigmatism correction BCHR_CAL= 'bchr1b003.fit ' / Background characteristics BKGD_CAL= 'bkgd1b011.fit ' / Background/scattered-light model BPM_CAL = 'A13301470021bttagfbpm.fit' / Bad-pixel map for this exposure CHID_CAL= 'chid1b014.fit ' / Windows for spectral extraction DIGI_CAL= 'digi001.fit ' / Reference file for digitizer values ELEC_CAL= 'elec005.fit ' / Detector parameters FLAT1CAL= ' ' / Flat-field correction #1 FLAT2CAL= ' ' / Flat-field correction #2 GEOM_CAL= 'geom1b016.fit ' / X and Y geometric corrections GRAT_CAL= 'grat005.fit ' / Grating motions HSKP_CAL= 'A1330147002hskpf.fit' / Housekeeping data JITR_CAL= 'A1330147002jitrf.fit' / Spacecraft jitter data MIRR_CAL= 'mirr002.fit ' / Mirror motions PARM_CAL= 'parm1b015.fit ' / Master parameter file PHAH_CAL= 'phah1b001.fit ' / Pulse height map for HIST data PHAX_CAL= 'phax1b005.fit ' / Low-pulse-height X distortion QUAL_CAL= 'qual1b020.fit ' / Quality flag (bad pixel) map RATE_CAL= 'rate1b002.fit ' / Y stretch with count rate SAAC_CAL= 'saac004.fit ' / SAA contours for data screening SCRN_CAL= 'scrn1b015.fit ' / Parameters for data screening SPEC_CAL= 'spec002.fit ' / Spectrograph parameters STIM_CAL= 'stim1b001.fit ' / Default thermal drift parameters TMXY_CAL= 'tmxy1b002.fit ' / Temporal X and Y corrections VOLT_CAL= 'volt1b009.fit ' / Detector bias voltages and dates WAVE_CAL= 'wave1b023.fit ' / Wavelength calibration WGTS_CAL= 'wgts1b011.fit ' / Pixel weights for extraction WORM1CAL= ' ' / Worm correction #1 WORM2CAL= ' ' / Worm correction #2
SCIENCE DATA PROCESSING KEYWORDS: This section collects other data which are relevant to the calibration. These keywords are populated by OPUS and/or by CalFUSE. Some of these keywords (e.g., limb angle; pulse height) reflect screening limits used when CalFUSE was executed (see The CalFUSE Page).
SCIENCE DATA PROCESSING KEYWORDS OPUSVERS= '2.7 ' / FUSE OPUS version number CF_VERS = '3.2.1 ' / CALFUSE pipeline version number HKEXISTS= 'yes ' / Housekeeping data file exists DAYNIGHT= 'BOTH ' / Use only DAY, NIGHT, or BOTH BRITLIMB= 15. / [deg] Bright limb avoidance angle DARKLIMB= 10. / [deg] Dark limb avoidance angle ORBPERID= 5998. / [s] Estimate of orbital period PHALOW = 2 / Pulse height screening low limit PHAHIGH = 24 / Pulse height screening high limit OPT_EXTR= 10 / Number of optimal extraction iterations STIM_L_X= 256.5767 / X centroid of left stim pulse STIM_L_Y= 749.4218 / Y centroid of left stim pulse STIM_R_X= 16144.58 / X centroid of right stim pulse STIM_R_Y= 772.1562 / Y centroid of right stim pulse FPADXLIF= -0.1579872 / [pixels] Correction for FPA position (LIF) FPADXSIC= -5.317671 / [pixels] Correction for FPA position (SIC) WPC = 0.013 / [A] Wavelength increment per pixel W0 = 900. / [A] Wavelength of first pixel DET_DEAD= 1.005887 / Mean detector deadtime correction factor IDS_DEAD= 1. / Mean IDS deadtime correction factor TOT_DEAD= 1.005887 / TOTAL deadtime correction factor
MEASURED SPECTRAL CENTROIDS: This section gives the position of the centroids of the spectra determined by CalFUSE. The quality keyword is set to HIGH if the centroid is measured from the target spectrum, MEDIUM if it is measured from airglow features, and LOW if it is taken from a reference file (see Dixon et al. (2007) for more details).
MEASURED SPECTRAL CENTROIDS YCENT1 = 688.1578 / [pixels] Y centroid of LIF HIRS spectrum YCENT2 = 809.5578 / [pixels] Y centroid of LIF MDRS spectrum YCENT3 = 558.6619 / [pixels] Y centroid of LIF LWRS spectrum YCENT5 = 193.9905 / [pixels] Y centroid of SIC HIRS spectrum YCENT6 = 321.1906 / [pixels] Y centroid of SIC MDRS spectrum YCENT7 = 60.5411 / [pixels] Y centroid of SIC LWRS spectrum YQUAL1 = 'MEDIUM ' / Quality of Y centroid value (LIF HIRS) YQUAL2 = 'MEDIUM ' / Quality of Y centroid value (LIF MDRS) YQUAL3 = 'HIGH ' / Quality of Y centroid value (LIF LWRS) YQUAL5 = 'MEDIUM ' / Quality of Y centroid value (SIC HIRS) YQUAL6 = 'MEDIUM ' / Quality of Y centroid value (SIC MDRS) YQUAL7 = 'HIGH ' / Quality of Y centroid value (SIC LWRS)
BACKGROUND SAMPLE REGIONS: This section provides the details of the regions on the detectors used to determine the backgrounds used by CalFUSE (see Chapter 7).
BACKGROUND SAMPLE REGIONS BKGD_NUM= 3 / Number of background regions specified BKG_MIN0= 160 / [pixels] bkgd sample region 0 - lower limit BKG_MIN1= 665 / [pixels] bkgd sample region 1 - lower limit BKG_MIN2= 891 / [pixels] bkgd sample region 2 - lower limit BKG_MIN3= 0 / [pixels] bkgd sample region 3 - lower limit BKG_MIN4= 0 / [pixels] bkgd sample region 4 - lower limit BKG_MIN5= 0 / [pixels] bkgd sample region 5 - lower limit BKG_MIN6= 0 / [pixels] bkgd sample region 6 - lower limit BKG_MIN7= 0 / [pixels] bkgd sample region 7 - lower limit BKG_MAX0= 450 / [pixels] bkgd sample region 0 - upper limit BKG_MAX1= 890 / [pixels] bkgd sample region 1 - upper limit BKG_MAX2= 930 / [pixels] bkgd sample region 2 - upper limit BKG_MAX3= 0 / [pixels] bkgd sample region 3 - upper limit BKG_MAX4= 0 / [pixels] bkgd sample region 4 - upper limit BKG_MAX5= 0 / [pixels] bkgd sample region 5 - upper limit BKG_MAX6= 0 / [pixels] bkgd sample region 6 - upper limit BKG_MAX7= 0 / [pixels] bkgd sample region 7 - upper limit
ENGINEERING KEYWORDS: A fair amount of the detector engineering snapshot data (engineering telemetry) is included in the FITS headers. The values included are shown below. Except for the Active Image Counters, only those values from the relevant detector segment are inserted into the header. The example keywords below are for segment 1B. For a description of the counters and masks, see the Instrument Handbook (2009). The counter information is used by CalFUSE (see Dixon et al. (2007)).
ENGINEERING KEYWORDS THERMCON= 'ON ' / Thermal control flag FESSRC = 'FES A ' / Source of FES dump data FESCENT = 'FES A ' / Source of FES centroid data GMODE = 'IDENTIFIED_TRACKING ' / Guidance mode TRACKON = 'OFF ' / Moving target tracking on ATCMDATT= 'AT COMMANDED ATTITUD ' / At commanded attitude Segment 1B Counters C1BSIC_B= 14101192 / SIC counter at beginning of integration C1BSIC_E= 14175036 / SIC counter at end of integration C1BLIF_B= 11704586 / LIF counter at beginning of integration C1BLIF_E= 12032091 / LIF counter at end of integration C1BDE_B = 13969564 / Digitized events counter at beginning of integr C1BDE_E = 14391379 / Digitized events counter at end of integration C1BAS_B = 15180958 / Autonomous shutdown (SAA) counter at beginning C1BAS_E = 15182787 / Autonomous shutdown (SAA) counter at end of int C1BFE_B = 3527277 / Fast event counter at beginning of integration C1BFE_E = 3954788 / Fast event counter at end of integration C1BFE_CR= 394.019348 / Count rate from fast event counter Active Image Counters CTIME_B = 5.182961006944E+04 / [MJD] Time of first engineering snapshot CTIME_E = 5.182962262731E+04 / [MJD] Time of last engineering snapshot C1AAI_B = 10760595 / Seg 1A at beginning C1AAI_E = 11259319 / Seg 1A at end of integration C1BAI_B = 13894835 / Seg 1B at beginning C1BAI_E = 14316651 / Seg 1B at end of integration C2AAI_B = 1067178 / Seg 2A at beginning C2AAI_E = 1679155 / Seg 2A at end of integration C2BAI_B = 2067772 / Seg 2B at beginning C2BAI_E = 2341339 / Seg 2B at end of integration Detector 1 parameters DET1ETMP= 25.9103 / DET1 electronics temperature DET1PTMP= 18.1937 / DET1 Baseplate temperature DET1ASCL= 17.0 / DET1 segment A Time (X) image scale factor DET1BSCL= 91.0 / DET1 segment B Time (X) image scale factor DET1AXOF= 183.0 / DET1 segment A Time (X) image position offset DET1BXOF= 107.0 / DET1 segment B Time (X) image position offset DET1TEMP= 18.4255 / DET1 Detector temperature DET1HVMT= 24.5318 / DET1 High Voltage Module temperature DET1HVFT= 20.9761 / DET1 High Voltage Filter temperature DET1AMAT= 26.3947 / DET1 segment A Amplifier temperature DET1AMBT= 26.3947 / DET1 segment B Amplifier temperature DET1TDAT= 21.386000 / DET1 TDC A temperature DET1TDBT= 21.792 / DET1 TDC B temperature DET1HVA = 57.0 / DET1 MCP A Bias Current DET1HVB = 48.0 / DET1 MCP B Bias Current DET1AUCT= 227.0 / DET1 TDC-A Upper Charge Threshold setting DET1BUCT= 228.0 / DET1 TDC-B Upper Charge Threshold setting DET1ABWK= 165.0 / DET1 TDC-A Begin CFD Walk setting DET1BBWK= 139.0 / DET1 TDC-B Begin CFD Walk setting DET1AEWK= 165.0 / DET1 TDC-A End CFD Walk setting DET1BEWK= 125.0 / DET1 TDC-B End CFD Walk setting DET1ABSL= 227.0 / DET1 TDC-A charge Baseline threshold setting DET1BBSL= 228.0 / DET1 TDC-B charge Baseline threshold setting DET1ALCT= 7.0 / DET1 TDC-A Lower Charge Threshold setting DET1BLCT= 6.0 / DET1 TDC-B Lower Charge Threshold setting DET1ALTT= 169.0 / DET1 TDC-A Lower Time Threshold setting DET1BLTT= 143.0 / DET1 TDC-B Lower Time Threshold setting DET1HVGR= 1.0 / DET1 Grid High Voltage Status DET1HVPW= 1.0 / DET1 Bias High Voltage Status DET1STIM= 'OFF ' / DET1 Stimulation Lamp Status
ARCHIVE SEARCH KEYWORDS: Finally, keywords used by the archive, and those necessary to associate the exposures that make up an observation are included.
ARCHIVE SEARCH KEYWORDS BANDWID = 99.99597 / [Angstroms] Bandwidth of the data CENTRWV = 949.998 / [Angstroms] Central wavelength of the data WAVEMIN = 900. / [Angstroms] Minimum wavelength of the data WAVEMAX = 999.996 / [Angstroms] Maximum wavelength of the data PLATESC = 1.163 / [arcsec/pixel] Plate scale ASSOCIATION KEYWORDS ASN_ID = 'A1330147000 ' / Unique identifier assigned to association ASN_TAB = 'A1330147000asn.fit ' / Name of the association table ASN_MTYP= 'EXPOSURE ' / Role of the exposure in the association
Subsets of the DATA DESCRIPTION keywords, PROPOSAL INFORMATION keywords, and TARGET INFORMATION keywords are also included in the housekeeping and jitter file headers. In addition, their headers contain unique keywords which are described in this section.
Housekeeping Keywords: The HDU1 header for the housekeeping files contains some of the keywords defined above plus a set of engineering housekeeping time keywords (shown below). These specify the start time of the engineering telemetry contained in the file, and are measured quantities. The TIME_ENG keyword value is normally about one-half to one minute before the actual start time of the science exposure.
ENGINEERING HOUSEKEEPING TIME HSKPVERS= '3.2 ' / Housekeeping version number DATE_ENG= '2000-09-27 ' / start date (yyyy-mm-dd) TIME_ENG= '11:03:16 ' / start time (hh:mm:ss)
The HDU2 headers of the housekeeping files simply contain definitions of the housekeeping variables listed in Appendix D, so they are not repeated here.
Jitter Keywords: The HDU1 headers for the jitter files contain the engineering housekeeping time keywords described above, as well as a unique set of jitter keywords. The jitter data are computed from the housekeeping data. Most of the jitter keywords reflect the results of that analysis, and are intended as indicators of the overall quality of the pointing during the science exposure.
JITTER KEYWORDS JIT_STAT= 0 / Status of jitter data is good JIT_VERS= '3.5 ' / cf_jitter version number QREF_SRC= 'TELEMETRY' / Source of reference quaternion QREF_0 = -0.0168658437405577 / Reference quaternion QREF_1 = 0.318041029256893 QREF_2 = 0.908345046651746 QREF_3 = 0.271062212872567 EXP_DUR = 668. / [s] duration of jitter data KNOWNTRK= 1. / fraction of exp in known track ACSTRK = 0. / fraction of exp in ACS track NOGDEINF= 0. / fraction of exp with no guiding info NGS_USED= 6 / number of guide stars used GS1_USED= 1. / fraction of exp using known guide star 1 GS2_USED= 1. / fraction of exp using known guide star 2 GS3_USED= 1. / fraction of exp using known guide star 3 GS4_USED= 1. / fraction of exp using known guide star 4 GS5_USED= 1. / fraction of exp using known guide star 5 GS6_USED= 1. / fraction of exp using known guide star 6 KTRKFINE= 1. / exp fraction, err < 15 arcsec, known stars ATRKFINE= 0. / exp fraction, err < 15 arcsec, ACS TOTLFINE= 1. / exp fraction, err < 15 arcsec, total GS_INUSE= 1. / fraction of exp tracking on guide stars SLEWFLG = -1 / Slew commanded during obs (if > 0) SLEWTIME= 0 / time spent slewing (sec) POSAVG_X= 0.02662656 / [arcsec] mean DX during known track POSAVG_Y= -0.01711245 / [arcsec] mean DY during known track X_JITTER= 0.326723 / [arcsec] sigma of DX during known track Y_JITTER= 0.136007 / [arcsec] sigma of DY during known track XJIT_15 = 0.326723 / [arcsec] sigma of DX for err < 15 arcsec YJIT_15 = 0.136007 / [arcsec] sigma of DY for err < 15 arcsec X_JITLRG= 0.03892216 / frac of DX more than 2-sigma from POSAVE_X Y_JITLRG= 0.05239521 / frac of DY more than 2-sigma from POSAVE_Y