HST Keyword Dictionary

Space Telescope Science Institute

3700 San Martin Drive

Baltimore, MD 21212

_____________________________________________________

Keyword Definitions for the

This is version 11.4, dated 16-NOV-1987

_____________________________________________________

ATODCORR
Do A-to-D correction: PERFORM, OMIT, COMPLETE
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 :

ATODGAIN
Analog to Digital Gain (Electrons/DN)
Datatype: REAL*4              
Units:                        

Source :

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

Source :

BACKGRND
estimated background level
Datatype: CHARACTER*          
Units:                        

Source :

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

Source :

BIASCORR
Do bias correction: PERFORM, OMIT, COMPLETE
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 for even-numbered columns
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 for odd-numbered columns
Datatype: CHARACTER*          
Units:                        

Source :

BLEVCORR
Do bias level correction: PERFORM, OMIT, COMPLETE
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 :

CDBSFILE
GENERIC/BIAS/DARK/FLAT/MASK/NO
Datatype: CHARACTER*18        
Units:                        

Source :

COMPTAB
the HST components table
Datatype: CHARACTER*18        
Units:    FILENAME            
See PHOTMODE and related photometry keywords.

Source :

DARKCORR
Do dark correction: PERFORM, OMIT, COMPLETE
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
the ccd number of the data
Datatype: CHARACTER*          
Units:                        
HRS: detector in use (1-2): WFPC: the ccd number of the data

Source :

DEZERO
Mean bias level from EED extended register
Datatype: CHARACTER*          
Units:                        

Source :

DOHISTOS
Make histograms: PERFORM, OMIT, COMPLETE
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: PERFORM, OMIT, COMPLETE
Datatype: CHARACTER*08        
Units:                        

Source :

DOSATMAP
Output saturated pixel map: PERFORM, OMIT, COMPLETE
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 :

FILTROT
partial filter rotation angle (degrees)
Datatype: REAL*4              
Units:                        

Source :

FLATCORR
Do flat field correction: PERFORM, OMIT, COMPLETE
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 :

GRAPHTAB
the HST graph table
Datatype: CHARACTER*18        
Units:    FILENAME            
See PHOTMODE and related photometry keywords.

Source :

HISTWIDE
width of the histogram
Datatype: CHARACTER*          
Units:                        

Source :

IMAGETYP
DARK/BIAS/IFLAT/UFLAT/VFLAT/KSPOT/EXT/ECAL
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]

LRFWAVE
linear ramp filter wavelength
Datatype: REAL*4              
Units:                        

Source :

MASKCORR
Do mask correction: PERFORM, OMIT, COMPLETE
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 :

MEANC10
mean of a 10x10 region at center of chip
Datatype: CHARACTER*          
Units:                        

Source :

MEANC100
mean of a 100x100 region at center of chip
Datatype: CHARACTER*          
Units:                        

Source :

MEANC200
mean of a 200x200 region at center of chip
Datatype: CHARACTER*          
Units:                        

Source :

MEANC25
mean of a 25x25 region at center of chip
Datatype: CHARACTER*          
Units:                        

Source :

MEANC300
mean of a 300x300 region at center of chip
Datatype: CHARACTER*          
Units:                        

Source :

MEANC50
mean of a 50x50 region at center of chip
Datatype: CHARACTER*          
Units:                        

Source :

MEDIAN
middle data value when good qual pixels sorted
Datatype: CHARACTER*          
Units:                        

Source :

MEDSHADO
median pixel value in shadow of pyramid edge
Datatype: CHARACTER*          
Units:                        

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 :

OVERLAP
number of "image overlap" pixels (DQF=64)
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]

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 :

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]

RA_SUN
right ascension of the sun (deg)
Datatype: REAL*8              
Units:    DEGREES             
is the predicted start of observation.

Source :[qobservation.rtascsun]

READTIME
Length of time for CCD readout in clock ticks
Datatype: INTEGER*4           
Units:                        

Source :

ROTRTTRG
rotation rate of target
Datatype: REAL*4              
Units:    DEGREES/DAY         
of longitude.

Source :[qobservation.long_rate]

RSDPFILL
bad data fill value for calibrated images
Datatype: INTEGER*2           
Units:    FILL_VALUE          

Source :

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 :

SHADCORR
Do shaded shutter correction: PERFORM, OMIT, COMPLETE
Datatype: CHARACTER*08        
Units:                        

Source :

SHADFILE
name of the reference file for shutter shading
Datatype: CHARACTER*18        
Units:                        

Source :

SHUTTER
Shutter in place at the beginning of the exposure (A or B)
Datatype: CHARACTER*01        
Units:                        

Source :

SKEWNESS
skewness of the histogram
Datatype: CHARACTER*          
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]

UBAY3TMP
bay 3 A1 temperature (deg C)
Datatype: REAL*4              
Units:                        

Source :

UCH1CJTM
TEC cold junction #1 temperature (Celsius)
Datatype: REAL*4              
Units:                        

Source :

UCH2CJTM
TEC cold junction #2 temperature (Celsius)
Datatype: REAL*4              
Units:                        

Source :

UCH3CJTM
TEC cold junction #3 temperature (Celsius)
Datatype: REAL*4              
Units:                        

Source :

UCH4CJTM
TEC cold junction #4 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)