HST Keyword Dictionary

Space Telescope Science Institute

3700 San Martin Drive

Baltimore, MD 21212

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Keyword Definitions for the

Wide Field Planetary Camera - I
Science Data Header

This is version 11.4, dated 16-NOV-1987

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ATODCORR: Do A-to-D correction: YES, NO, DONE; Datatype: CHARACTER*08 Units:; Replace each pixel with the appropriate value from the AtoD correction lookup table. The name of the lookup table must be provided in the keyword ATODFILE. The AtoD table may consist of multiple lookup tables. The lookup table whose temperature is closest to the value of the input science image header keyword WBA3PCTM is selected.
Source :(calguide)

ATODFILE: name of the A-to-D conversion file; Datatype: CHARACTER*18 Units: FILENAME; The A-to-D lookup table files are used to correct the image data for a pattern introduced by the Analog to Digital converter electronics. This is done by replacing the short integer pixel values obtained from the WF/PC with floating point values that remove the systematic degradation introduced by this hardware problem.
Source :

ATODSAT: number of "AtoD saturated" pixels (DQF=8); Datatype: CHARACTER* Units:; Source :

BADPIXEL: number of "generic bad" pixels (DQF=32); Datatype: CHARACTER* Units:; Source :

BIASCORR: Do bias correction: YES, NO, DONE; Datatype: CHARACTER*08 Units:; Subtract the bias image reference file from the input science image. The names of the bias image and its DQF must be provided in the keywords BIASFILE and BIASDFIL.
Source :(calguide)

BIASDFIL: name of the bias frame reference DQF; Datatype: CHARACTER*18 Units:; Source :

BIASEVEN: Bias level from EED extended register; Datatype: CHARACTER* Units:; Bias level from EED extended register Information garnered from columns 3-14 of the extracted engineering (.x0h) file. Note that the BIASEVEN value should be the mean of columns 3,5,7,9..., and the BIASODD value should be the mean of columns 4,6,8,10,...---i.e., the overscan columns are 180 degrees out of phase from the science image. (opr.21796)
Source :

BIASFILE: name of the bias frame reference file; Datatype: CHARACTER*18 Units: FILENAME; The structure in the electronic bias is removed by subtracting the bias reference file (with its accompanying data quality file). The most notable component of this structure is a 0.6 DN even/odd column pattern. The BIASDFIL is the name of the bias frame reference data quality file.
Source :

BIASODD: Bias level from EED extended register; Datatype: CHARACTER* Units:; Source :

BLEVCORR: Do bias level correction: YES, NO, DONE; Datatype: CHARACTER*08 Units:; Determine the global bias level from the mean of the extended register pixels in the extracted engineering data file (.x0h) and subtracted from each pixel in the input science image. Only pixels not flagged in the extracted engineering DQF (.q1h) are included in the averaging. The names of these files must be provided in the keywords BLEVFILE and BLEVDFIL.
Source :(calguide)

BLEVDFIL: Engineering file DQF; Datatype: CHARACTER*18 Units: FILENAME; Source :

BLEVFILE: Engineering file with extended register data; Datatype: CHARACTER*18 Units: FILENAME; Source :

CALIBDEF: number of "calibration defect" pixels (DQF=2); Datatype: CHARACTER* Units: COUNT; Source :

CAMERA: camera in use: WF (wide-field), PC (planetary); Datatype: CHARACTER*02 Units:; This indicates which of the two cameras was used to obtain the scientific data. The possible values are 'WIDE-FIELD' and 'PLANETARY'.
Source :[qexposure.camera]

CDBSFILE: GENERIC/BIAS/DARK/PREF/FLAT/MASK/ATOD/NO; Datatype: CHARACTER*18 Units:; Source :

DARKCORR: Do dark correction: YES, NO, DONE; Datatype: CHARACTER*08 Units:; Scale the dark image reference file and subtract it from the input science image. The dark image is multiplied by the total dark accumulation time (obtained from the keyword DARKTIME in the input science image header, and expressed in seconds) and then subtracted from the input science image. The names of the dark image and its DQF must be provided in the keywords DARKFILE and DARKDFIL.
Source :(calguide)

DARKDFIL: name of the dark reference DQF; Datatype: CHARACTER*18 Units:; Source :

DARKFILE: name of the dark reference file; Datatype: CHARACTER*18 Units: FILENAME; The WF/PC dark reference file and its associated data quality file are used to correct the dark current. The WF/PC CCDs generate a spurious signal during exposures known as dark current. This signal is a function of the time since the last erase command and the operating temperature of the CCD detectors and varies from pixel to pixel. The dark reference file is scaled by the time since the last erase command and subtracted from the image. The DARKDFIL is the name fo the dark reference data quality file.
Source :

DARKTIME: Dark time (seconds); Datatype: REAL*4 Units: SECONDS; Source :

DATALOST: number of "data lost" pixels (DQF=16); Datatype: CHARACTER* Units: COUNTS; Source :

DATAMEAN: mean value of the "good" pixels; Datatype: CHARACTER* Units: COUNTS; Source :

DEC_SUN: declination of the sun (deg); Datatype: REAL*8 Units: DEGREES; Source :[qobservation.declsun]

DETECTOR: CCD detector: WFC 1-4, PC 5-8; Datatype: CHARACTER* Units:; HRS: detector in use (1-2): WFPC: the ccd number of the data
Source :

DEZERO: Bias level from EED extended register; Datatype: CHARACTER* Units:; Source :

DOHISTOS: Make histograms: YES, NO, DONE; Datatype: CHARACTER*08 Units:; Create an image of three rows containing histograms of the pixel values in the input science image, following AtoD correction, and in the output (.c0h) image, respectively. This file has the extension .c2h.
Source :(calguide)

DOPHOTOM: Fill photometry keywords: YES, NO, DONE; Datatype: CHARACTER*08 Units:; Source :

DOSATMAP: Output Saturated Pixel Map: YES, NO, DONE; Datatype: CHARACTER*08 Units:; Create a DQF flagging those pixels in the input science image which saturated the AtoD converter, or for which data was lost in transmission. This file has the extension .c3h.
Source :(calguide)

EPLONGPM: epoch of longitude of prime meridian; Datatype: REAL*4 Units: SECONDS; longitude of prime meridian of planetary target. seconds from 1980.
Source :[qtargets.epo_prim_mer]

EQNX_SUN: equinox of the sun; Datatype: REAL*4 Units:; Source :

EQRADTRG: equatorial radius of target; Datatype: REAL*4 Units: KILOMETERS; radius of planetary target.
Source :[qobservation.equ_radius]

FILTER1: first filter number (0-48); Datatype: INTEGER*2 Units:; This holds the number of the first filter used. Possible values are 0 to 48 (0 meaning the clear filter and 1-48 meaning one of the 48 filters).
Source :[qexposure.filter1]

FILTNAMi: first filter name; Datatype: CHARACTER*08 Units:; Source :

FLATCORR: Do flat field correction: YES, NO, DONE; Datatype: CHARACTER*08 Units:; Correct the input science image for variations in gain among pixels by applying a flat-field image. The input science image is multiplied by the flat-field image. The names of the flat field image and its DQF must be provided in the keywords FLATFILE and FLATDFIL.
Source :(calguide)

FLATDFIL: name of the flat field reference DQF; Datatype: CHARACTER*18 Units:; Source :

FLATFILE: name of the flat field reference file; Datatype: CHARACTER*18 Units: FILENAME; The variations in sensitivity between pixels in the CCD detectors are corrected by applying a flat field reference file. This file contains the normalized inverse sensitivity (gain) for each pixel in the detector. It is made from internal flat lamp exposures, the combination of streaked earth flats or processed observations of astronomical sources. The image is multiplied by the flat field file after correcting for bias, preflash, superpurge, and dark. The FLATDFIL is the name of the flat field reference data quality file.
Source :

FLATNTRG: flattening of target; Datatype: REAL*4 Units: ???; planetary target, the difference between the equatorial and polar radius divided by the equatorial radius.
Source :[qobservation.flattening]

GOODMAX: maximum value of the "good" pixels; Datatype: CHARACTER* Units:; Source :

GOODMIN: minimum value of the "good" pixels; Datatype: CHARACTER* Units:; Source :

GPIXELS: number of "good" pixels (DQF=0); Datatype: CHARACTER* Units: COUNT; Source :

IMAGETYP: DARK/BIAS/INTFLAT/KSPOTS/EXTERNAL/EARTH-CALIB; Datatype: CHARACTER*18 Units:; Source :

KSPOTS: Status of Kelsall spot lamps: ON, OFF; Datatype: CHARACTER*03 Units:; Determined by PODPS on the basis of the packet format code of the observation: KSPOTS=OFF unless the packet format code='24'x or '2C'x. (cgwsdh)
Source :

LINEBEG: line number (1st line: wrt source format); Datatype: INTEGER*2 Units:; Source :

LONGPMER: longitude of prime meridian; Datatype: REAL*4 Units: DEGREES; prime meridian of planetary target.
Source :[qtargets.long_prim_me]

MASKCORR: Do mask correction: YES, NO, DONE; Datatype: CHARACTER*08 Units:; Include the static bad pixel mask in the output DQF. The name of the static bad pixel mask must be provided in the keyword MASKFILE. This file is in the same format as a DQF.
Source :(calguide)

MASKFILE: name of the input DQF of known bad pixels; Datatype: CHARACTER*18 Units: FILENAME; The static mask files (formerly known as the data quality masks) contain flags for those pixels which always contain degraded values. This mask is routinely incorporated into the data quality file generated in the RSDP pipeline by calwfp. The static mask file is a short integer (INTEGER*2) image file of of four (4) groups with the same dimensions as the WF/PC science image. The image contains values of zero (0) in all pixels, except for those with known static defects. Defective pixels are flagged with the value four (4).
Source :

MIR_REVR: is the image mirror reversed?; Datatype: CHARACTER* Units:; Source :

MODE: instr. mode: FULL (full res.), AREA (area int.); Datatype: CHARACTER*04 Units:; FULL = full-resolution (800X800), AREA = area-integration (400x400);

Source :[qexposure.mode]

MTFLAG: moving target flag; Datatype: LOGICAL*1 Units:; Source :[qobservation.mt_flag]

NPDECTRG: north pole declination of target; Datatype: REAL*4 Units: DEGREES; north pole of planetary target.
Source :[qobservation.north_dec]

NPRATRG: north pole right ascension of target; Datatype: REAL*4 Units: DEGREES; Source :

NSHUTA17: Number of AP17 shutter B closes; Datatype: INTEGER*4 Units:; Source :

ORIENTAT: orientation of the image (deg); Datatype: CHARACTER* Units:; Source :

PA_V3: position angle of v3 axis of HST; Datatype: REAL*4 Units: DEGREES; This is the angle from North, towards East, of the Y-axis of the vehicle coordinate system. The direction of North is taken at the V1-axis. Position angles measured from North at different right ascensions, such as at the target position for PA_APER or the aperture reference position for ORIENTAT, will include a small correction for the difference in the direction of North.
Source :[qobservation.psanglv3]

PFILTERi: Preflash Filter 1 number (0-48); Datatype: INTEGER*2 Units:; Source :

PKTFMT: packet format code; Datatype: INTEGER*4 Units:; Type of Exposure WF PC ---------------- ----- ----- EXTERNAL '60'X '61'X w/PREFLASH '62'X '63'X w/PURGE '64'X '65'X w/PURGE & PREFLASH '66'X '67'X EXTERNAL '68'X '69'X with Serial Clocks On w/PREFLASH '6A'X '6B'X with Serial Clocks On w/PURGE '6C'X '6D'X with Serial Clocks On w/PURGE & PREFLASH '6E'X '6F'X with Serial Clocks On BIAS '20'X '28'X DARK '21'X '29'X INTFLAT '22'X '2A'X EXTFLAT '23'X '2B'X KSPOT '24'X '2C'X UVFLOOD '25'X '2D'X DARK w/CLOCKS=ON '26'X '2E'X PREFLASH '27'X '2F'X

Source :

PREFCORR: Do preflash correction: YES, NO, DONE; Datatype: CHARACTER*08 Units:; If the value in keyword PREFTIME is less than zero, the preflash image reference file is scaled and subtracted from the input science image. The preflash image is multiplied by the preflash lamp exposure time (obtained from the keyword PREFTIME in the input science image header and expressed in seconds) and then subtracted from the input science image. If the keyword PREFTIME = 0, the CTE fixup is applied. The names of the preflash or CTE image and its DQF must be provided in the keywords PREFFILE and PREFDFIL.
Source :(calguide)

PREFDFIL: name of the preflash reference DQF; Datatype: CHARACTER*18 Units:; Source :

PREFFILE: name of the preflash reference file; Datatype: CHARACTER*18 Units: FILENAME; The WF/PC Preflash Reference File and its associated data quality file are used to remove the signal introduced by the preflash lamp. This signal is removed by subtracting this reference file. The reference file is scaled by the preflash exposure time to allow for variations in the requested preflash exposure. The subtraction of the reference file corrects for the uneven illumination pattern of the preflash image. Since the preflash is obtained by illuminating the backside of the shutter with an internal lamp, the difference in reflectivity of the two shutter blades requires reference files specific to each shutter blade. The PREFDFIL is the name of the preflash reference data quality file.
Source :

PREFTIME: Predicted preflash time (seconds); Datatype: REAL*4 Units: SECONDS; Source :

PSTPTIME: Predicted obs. stop time (yyyy:ddd:hh:mm:ss); Datatype: CHARACTER* Units: DATE; execution where: yyyy is year,
ddd is day of year, hh is hour, mm is minutes, ss is seconds.

Source :[qobservation.pred_stop_tm]

PSTRTIME: Predicted obs. start time (yyyy:ddd:hh:mm:ss); Datatype: CHARACTER* Units: DATE; execution where:
yyyy is year, ddd is day of year, hh is hour, mm is minutes, ss is seconds.

Source :[qobservation.pred_strt_tm]

PURGCORR: Do purge correction: YES, NO, DONE; Datatype: CHARACTER*08 Units:; The names of the superpurge image and its DQF must be provided in the keywords PURGFILE and PURGDFIL. The scaling is obtained from the keywords DARKTIME and PURGTIME.
Source :(calguide)

PURGDFIL: name of the purge reference DQF; Datatype: CHARACTER*18 Units:; Source :

PURGFILE: name of the purge reference file; Datatype: CHARACTER*18 Units: FILENAME; The WF/PC superpurge reference file and its associated data quality file are used in the superpurge calibration procedure. The superpurge procedure removes residual images of highly overexposed sources. However, it creates a non-uniform residual image over the entire detector which decays with time. The level of this global residual image in a readout depends upon both the time since the purge was performed and the time since the last erase prior to the readout. The superpurge reference file must be scaled and subtracted from all images obtained after a superpurge in which the residual is still significant. The PURGDFIL is the name of the purge reference data quality file.
Source :

PURGTIME: Time since last SuperPurge (seconds); Datatype: REAL*4 Units: SECONDS; The time of the observation, which was dredged from qobservation, is used to establish the search limit. 24 hours are subtracted from the current observation time, and a join of qolink and qesiparm is queried to determine if any purge observations were taken within the previous 24 hours. If one is found, the number of seconds is calculated. If none are found, the limit of 24 hours (172800 seconds) is written into the keyword PURGTIME. (cgwprg)
Source :

RA_SUN: right ascension of the sun (deg); Datatype: REAL*8 Units: DEGREES; is the predicted start of observation.
Source :[qobservation.rtascsun]

ROTRTTRG: rotation rate of target; Datatype: REAL*4 Units: DEGREES/DAY; of longitude.
Source :[qobservation.long_rate]

SAMPBEG: sample number (1st sample: wrt source format); Datatype: INTEGER*2 Units:; Source :

SATURATE: Data value at which saturation occurs; Datatype: INTEGER*2 Units:; Source :

SERIALS: serial clocks: ON, OFF; Datatype: CHARACTER*03 Units:; Determined by PODPS on the basis of the packet format code of the observation. Serial clocks are on if the packet format code = '68'x. (cgwsdh)
Source :

SHUTTER: Shutter in place during preflash or INTFLAT; Datatype: CHARACTER*07 Units:; Source :

SOFTERRS: number of "soft error" pixels (DQF=1); Datatype: CHARACTER* Units: COUNT; Source :

STATICD: number of "static defect" pixels (DQF=4); Datatype: CHARACTER* Units: COUNT; Source :

SURFALTD: surface feature altitude; Datatype: REAL*4 Units: KILOMETERS; surface feature.
Source :[qobservation.feature_alt]

SURFLATD: surface feature latitude; Datatype: REAL*4 Units: DEGREES; surface feature.
Source :[qobservation.feature_lat]

SURFLONG: surface feature longitude; Datatype: REAL*4 Units: DEGREES; surface feature.
Source :[qobservation.feature_long]

TECTEMPi: TEC cold junction #1 temperature (Celsius); Datatype: REAL*4 Units:; Source :

WBA3PCTM: Bay 3 temperature (Celsius); Datatype: REAL*4 Units:; Source :

WEXPODUR: Commanded duration of exposure (seconds); Datatype: INTEGER*4 Units: SECONDS; Source :

WEXPOTIM: Major frame pulse time preceding exposure start (cnts); Datatype: INTEGER*4 Units:; Decimal representation of the 16 low order bits (lsb) of the time tag given by the spacecraft to the major frame pulse (mfp) preceding the start of a WFPC exposure. (ETS-c)
Source :

WSCALE: Scale factor for output image; Datatype: REAL*4 Units:; Source :

WZERO: Zero point for output image; Datatype: REAL*4 Units:; Source :

HST Keyword Dictionary: 3/15/94: (rose@stsci.edu)