Mapping to Existing Headers

This document provides a few comparisons between current NOAO (Kitt Peak) headers and the proposed headers. This maps the keywords in current headers to the proposed header. This does not add keywords not in the current but which would be used in the proposed headers.


1. WIYN HYDRA Spectrum with WIYN HARCON

The following shows a mapping from an early Hydra header created with the WIYN HARCON system. This is a one amplifier readout with on-chip summing.

Current Header

SIMPLE  =                    T  /  FITS STANDARD
BITPIX  =                   32  /  FITS BITS/PIXEL
NAXIS   =                    2  /  NUMBER OF AXES
NAXIS1  =                 2080  /
NAXIS2  =                  512  /
OBJECT  = 'Pleiades 0 offset e'  /
HDR_REV = '1.010  13Jul94     (title @ end of pic; UTSHUT)' /
ORIGPIC = 'obj0051'            / Original picture file name
OPICNUM =                   51 / Original picture number
NAMPSYX = '1 1'                / Num amps in y & x (eg. '2 2'=quad)
AMPLIST = '12'                 / Readout order in y,x
OBSERVAT= 'KPNO'               / Origin of data
TELESCOP= 'WIYN3.5m'           / Specific system
DETECTOR= 't2kc'               / Detector (CCD type, photon counter, etc.)
IMAGETYP= 'OBJECT'             / Type of picture (object, dark, etc.)
PREFLASH=             0.000000 / Preflash time in secs
CCDSUM  = '1 4'                / On chip summation (X,Y)
BIASSEC = '[1:32,1:512]'       / Bias section definition
CCDSEC  = '[1:2048,1:512]'     / Section in full CCD for DATASEC
DATASEC = '[33:2080,1:512]'    / Image area in raw frame
TRIMSEC = '[34:2080,1:512]'    / Trim section definition
DATE-OBS= '11/11/95'           / Date (dd/mm/yy) of observation
UTSHUT  = '11:02:47.0'         / UT of shutter open
EXPTIME =              180.000 / Exposure time in secs
DARKTIME=              180.870 / Total elapsed time in secs
GAIN_12 = '1.7'                / gain, electrons per ADU
NOISE_12= '4.3'                / read noise, electrons
DCS_TIME=                15000 / (ns) DCS integrator slope time
READTIME=                39480 / (ns) unbinned pixel read time
WAVEMODE= 'OverlapXmit EarlyReset' / Waveform options enabled
WAVEFILE= 'Obs Fri Nov 10 22:50:17 1995' /
RECID   = 'wiyn.hydra.951111.110247' / archive ID for observation
UT      = '11:02:45.26'         /  universal time
ST      = ' 6:56:51.45'         /  sidereal time
EL      = '47:37:7.83'         / elevation
AZ      = '271:58:38.79'       / azimuth
TRACK   = 'enabled'            / tracking
COORDS  = 'Helio. mean FK5'    / coordinate system
RADECSYS= 'FK5'                / coordinate system
RA      = ' 3:46:32.20'         /  right ascension
DEC     = '24:16:54.00'         /  declination
EQUINOX =               2000.0 / equinox of position
EPOCH   =               2000.0 / same as EQUINOX (for back compat.)
ZD      =               42.359 / zenith distance
AIRMASS =             1.352262 / airmass at start of exposure
ROTANGLE=                -34.0 / rotator angle, degrees CW from N
FIBCABLE= 'RED'                / Hydra Fiber Cable Name
SLFIB1  = '1 2 00:00:00.00 00:00:00.0  SCS' /
SLFIB2  = '2 1  3:45:20.30 24:17:35.1 278882  10.10 (171)' /
[etc]
GRATNAME= '400@4.2'            / grating name
GRATANGL=               21.281 / grating angle (degrees)
CAMANGLE=               30.000 / camera-collimator angle (degrees)
DEWARANG=                0.000 / dewar azimuth (degrees)
FILTNAMC= 'G3_GG-375'          / bench filter c (in beam)
FIBFOCUS=               -0.212 / fiber focus (inches)
CAMFOCUS=               -0.054 / camera focus (inches)
CAMNAME = 'Simmons'            / camera name

Proposed Header

SIMPLE  =                    T / FITS format
BITPIX  =                   16 / Number of bits per pixel
NAXIS   =                    2 / Number of image axes
NAXIS1  =                 2080 / Number of pixels
NAXIS2  =                  512 / Number of pixels
OBJECT  = 'Pleiades 0 offset e' / Observation title
DATAACQ = '1.010  13Jul94'     / Data system software version
FILENAME= 'obj0051'            / Original filename
OBSERVAT= 'KPNO    '           / Observatory
TELESCOP= 'WIYN3.5m'           / Telescope
DETECTOR= 't2kc    '           / Detector
OBSTYPE = 'OBJECT  '           / Observation type
PREFLASH=                  0.0 / Preflash time (sec)
CCDSUM  = '1 4     '           / CCD on-chip summing
BIASSEC = '[1:32,1:512]'       / Bias section
CCDSEC  = '[1:2048,1:2048]'    / Region of CCD read
DATASEC = '[33:2080,1:512]'    / Data section
TRIMSEC = '[34:2048,1:512]'    / Section of useful data
DATE-OBS= '11/11/95'           / UTC date of observation
UTC     = '11:02:47.0'         / UTC of observation
EXPTIME =              180.000 / Exposure time (seconds)
DARKTIME=              180.870 / Dark time (seconds)
GAIN    =                  1.7 / CCD gain (e/ADU)
RDNOISE =                  4.3 / Readout noise (e)
AMPINTEG=               15000. / Amplifier integration time (ns)
AMPREAD =               39480. / Amplifier pixel read time (ns)
ARCONWM = 'OverlapXmit EarlyReset' / Waveform options enabled
ARCONWF = 'Obs Fri Nov 10 22:50:17 1995' / Wavefile
OBSID   = 'wiyn.hydra.951111.110247' / Observation identification
IMAGEID =                    1 / Image identification
MJDHDR  =         50032.460246 / MJD of header creation
LST     = '06:56:51.45'        / LST of observation
TELAL   = '47:37:07.83'        / Telescope altitude
TELAZ   = '271:58:38.79'       / Telescope azimuth
TELSTAT = 'enabled '           / Telescope status
RADECSYS= 'FK5     '           / Default coordinate system
RA      = '03:46:32.20'        / Right ascension (hours)
DEC     = '24:16:54.00'        / Declination (degrees)
EQUINOX =               2000.0 / Default coordinate equinox
EPOCH   =               2000.0 / Default coordinate epoch
ZD      =               42.359 / Zenith distance (degrees)
INSTCONF= 'Red Cable'          / Instrument configuration
FIBER   = '1 2 00:00:00.00 00:00:00.0  SCS' /
FIB00002= '2 1  3:45:20.30 24:17:35.1 278882  10.10 (171)' /
[etc]
DISPER  = 'RC-181  '           / Disperser
DISPAN  =               21.281 / Disperser angle (deg)
CAMPAN  =                 30.0 / Camera angle (deg)
DEWPAN  =                0.000 / Dewar angle (deg)
FILTER  = 'G3_GG-375'          / Bench filter c (in beam)
INSFOCUS=               -0.212 / Fiber focus (inches)
CAMFOCUS=               -0.054 / Camera focus (inches)
CAMERA  = 'Simmons'            / Camera name
The mapping between HDR_REV and DATAACQ is not completely appropriate. The convention for CCDSEC when binning was not really defined earlier. The proposed definition requires it to be in unbinned CCD pixels. The UTC keyword corresponds to the UTSHUT keyword and the UT keyword is translated to the MJDHDR which is the modified Julian date at the time the header is created. The following keywords could not be mapped:

2. Coude Feed Arc Spectrum with ICE

The following shows a mapping from a 1993 Coude Feed arc spectrum.

Current Header

SIMPLE  =                    T  /  FITS STANDARD
BITPIX  =                   16  /  FITS BITS/PIXEL
NAXIS   =                    2  /  NUMBER OF AXES
NAXIS1  =                 2080  /
NAXIS2  =                  100  /
OBJECT  = 'THORIUM-ARGON ARC: 3900A-7290A 0.17A/pixel'  /
OBSERVAT= 'KPNO              '  /  observatory
EXPTIME =                  10.  /  actual integration time
DARKTIME=                  10.  /  total elapsed time
IMAGETYP= 'comp              '  /  object, dark, bias, etc.
DATE-OBS= '28/07/93          '  /  date (dd/mm/yy) of obs.
UT      = '23:22:39.00'         /  universal time
ST      = '12:22:46.00'         /  sidereal time
RA      = ' 7:14:06.00'         /  right ascension
DEC     = '-52:49:33.00'        /  declination
EPOCH   =               1993.6  /  epoch of ra and dec
ZD      = '107.930           '  /  zenith distance
AIRMASS =                 99.9  /  airmass
TELESCOP= 'kpcdf             '  /  telescope name
DETECTOR= 't2kb              '  /  detector
PREFLASH=                    0  /  preflash time, seconds
GAIN    =                  2.6  /  gain, electrons per adu
DWELL   =                    8  /  sample integration time
RDNOISE =                   4.  /  read noise, electrons per adu
CAMTEMP =                 -103  /  camera temperature
DEWTEMP =                 -121  /  dewar temperature
BIASSEC = '[2049:2080,1:100] '  /  overscan portion of frame
TRIMSEC = '[1:2048,1:100]    '  /  region to be extracted
DATASEC = '[1:2048,1:100]    '  /  image portion of frame
CCDSEC  = '[1:2048,560:659]  '  /  orientation to full frame
ORIGSEC = '[1:2048,1:2048]   '  /  original size full frame
CCDSUM  = '1 1               '  /  on chip summation
INSTRUME= 'test              '  /  instrument
COMPLAMP= 'thar              '  /  comparison lamp
GRATPOS =               8802.8  /  grating position
RECID   = 'kpcdf.930728.232239'

Proposed Header

SIMPLE  =                    T / FITS format
BITPIX  =                   16 / Number of bits per pixel
NAXIS   =                    2 / Number of image axes
NAXIS1  =                 2080 / Number of pixels
NAXIS2  =                  100 / Number of pixels
OBJECT  = 'THORIUM-ARGON ARC: 3900A-7290A 0.17A/pixel'  / Observation title
OBSERVAT= 'KPNO              '  /  Observatory
EXPTIME =                  10. / Exposure time (seconds)
DARKTIME=                  10. / Dark time (seconds)
OBSTYPE = 'comp    '           / Observation type
DATE-OBS= '28/07/93'           / UTC date of observation
UTC     = '23:22:39.00'        / UTC of observation
LST     = '12:22:46.00'        / LST of observation
RA      = ' 7:14:06.00'        / Right ascension (hours)
DEC     = '-52:49:33.00'       / Declination (degrees)
EPOCH   =               1993.6 / Epoch of ra and dec
ZD      =              107.930 / Zenith distance (deg)
AIRMASS =                 99.9 / Airmass
TELESCOP= 'kpcdf   '           / Telescope
DETECTOR= 't2kb    '           / Detector
PREFLASH=                  0.0 / preflash time, seconds
GAIN    =                  2.6 / CCD gain (e/ADU)
AMPINTEG=                8000. / Amplifier integration time (ns)
RDNOISE =                   4. / Readout noise (e)
CAMTEM  =                 -103 / Camera temperature (deg C)
DEWTEM  =                 -121 / Dewar temperature (deg C)
BIASSEC = '[2049:2080,1:100] ' / Bias section
TRIMSEC = '[1:2048,1:100]    ' / Section of useful data
DATASEC = '[1:2048,1:100]    ' / Data section
CCDSEC  = '[1:2048,560:659]  ' / Region of CCD read
CCDSIZE = '[1:2048,1:2048]   ' / CCD size
CCDSUM  = '1 1               ' / CCD on-chip summing
INSTRUME= 'test              ' / Instrument
LAMP    = 'thar              ' / Lamp
DISPOS  =               8802.8 / Disperser position
OBSID   = 'kpcdf.930728.232239' / Observation identification
IMAGEID =                    1 / Image identification

The INSTRUME keyword is not really appropriate.


3. CTIO BIAS Image with ARCON

The following shows a mapping from an recent CTIO/ARCON header. This uses two amplifiers and creates a two dimensional image with the overscans in the middle of the image.

Current Header

SIMPLE  =                    T / FITS format
BITPIX  =                   16 / Number of bits per pixel
NAXIS   =                    2 / Number of bits per pixel
NAXIS1  =                 2206 / Number of bits per pixel
NAXIS2  =                 2046 / Number of bits per pixel
OBJECT  = 'bias frames'
HDR_REV = '1.010  13Jul94     (title @ end of pic; UTSHUT)' /
ORIGPIC = 'zero001'            / Original picture file name
OPICNUM =                    1 / Original picture number
NAMPSYX = '1 2'                / Num amps in y & x (eg. '2 2'=quad)
AMPLIST = '11 12'              / Readout order in y,x
OBSERVAT= 'CTIO'               / Origin of data
TELESCOP= 'CTIO 0.9 meter telescope' / Specific system
DETECTOR= 'Tek2K_3'            / Detector (CCD type, photon counter, etc.)
IMAGETYP= 'BIAS'               / Type of picture (object, dark, etc.)
PREFLASH=             0.000000 / Preflash time in secs
CCDSUM  = '1 1'                / On chip summation (X,Y)
ASEC11  = '[1:1103,1:2046]'    / Section read with Amp11
CSEC11  = '[1:1039,1:2046]'    / Section in full CCD for DSEC11
DSEC11  = '[1:1039,1:2046]'    / Image area in raw frame for Amp11
TSEC11  = '[16:1039,1:2046]'   / Trim section definition for Amp11
BSEC11  = '[1050:1103,1:2046]' / Bias section definition for Amp11
BSEC12  = '[1104:1157,1:2046]' / Bias section definition for Amp12
ASEC12  = '[1104:2206,1:2046]' / Section read with Amp12
CSEC12  = '[1040:2078,1:2046]' / Section in full CCD for DSEC12
DSEC12  = '[1168:2206,1:2046]' / Image area in raw frame for Amp12
TSEC12  = '[1168:2191,1:2046]' / Trim section definition for Amp12
OBSERVER= 'R.Jeffries'         / Observers
WAVEFILE= 'Obs Tue Mar  5 17:34:11 1996' /
WAVEMODE= 'MPP'                / Waveform mode switches on
GTRON22 =                3.900 / (e-) predicted read noise, upper right
GTRON21 =                3.900 / (e-) predicted read noise, upper left
GTRON12 =                4.100 / (e-) predicted read noise, lower right
GTRON11 =                4.100 / (e-) predicted read noise, lower left
GTGAIN22=                3.200 / (e-/ADU), predicted gain, upper right
GTGAIN21=                3.200 / (e-/ADU) predicted gain, upper left
GTGAIN12=                3.200 / (e-/ADU) predicted gain, lower right
GTGAIN11=                3.300 / (e-/ADU) predicted gain, lower left
GTINDEX =                    2 / Gain selection (index into Gain Table)
DCS_TIME=                 7000 / (ns) Double Correlated Sample time
DATE-OBS= '05/03/96'           / Date (dd/mm/yy) of observation
UTSHUT  = '21:08:33.0'         / UT of shutter open
UT      = '21:08:32.0'         / UT of TCS coords
RA      = '00:49:36.10'        / right ascension (telescope)
DEC     = '-28:01:45.5'        / declination (telescope)
EPOCH   =               2000.0 / epoch of RA & DEC
ZD      =                 33.1 / zenith distance (degrees)
HA      = '02:31:50.6'         / hour angle (H:M:S)
ST      = '03:20:54.7'         / sidereal time
RECID   = 'ct15m.950706.014158.390
AIRMASS =                1.193 / airmass
EXPTIME =                0.000 / Exposure time in secs
DARKTIME=                0.170 / Total elapsed time in secs
COMMENT METEOROLOGICAL INFORMATION
WEATDATE= 'Mar 05 21:06:02 1996' / Date and time of last update
WINDSPD = '6.2'                / Wind speed (mph)
WINDDIR = '84'                 / Wind direction (degrees)
AMBTEMP = '19.4'               / Ambient temperature (degrees C)
HUMIDITY= '55'                 / Ambient relative humidity (percent)
PRESSURE= '783'                / Barometric pressure (millibars)
COMMENT INSTRUMENT PARAMETERS
INSTRUME= 'cfccd'              / cassegrain direct imager
FILTER1 = 'dia'                / Filter in wheel one
FNAME1  = 'diafragma'          / Full name of filter in  wheel1
FILTER2 = 'v'                  / Filter in wheel two
FNAME2  = 'Vtek#2'             / Full name of filter in  wheel2
FILTERS = 'dia v'              / Filter positions
TELFOCUS=                    0 / Telescope focus

Proposed Header

------------------- PHU --------------------------------------------------------
SIMPLE  =                    T / FITS format
BITPIX  =                   16 / Number of bits per pixel
NAXIS   =                    0 / Number of bits per pixel
EXTEND  =                    T / FITS extensions
NEXTEND =                    2 / Number of image extensions
OBJECT  = 'bias frames'        / Observation title
DATAACQ = '1.010  13Jul94'     / Data system software version
FILENAME= 'zero001 '           / Original filename
CCDNAMPS=                    2 / Number of amplifiers
OBSERVAT= 'CTIO    '           / Observatory
TELESCOP= 'CTIO 0.9 meter telescope' / Telescope
DETECTOR= 'Tek2K_3 '           / Detector
OBSTYPE = 'BIAS    '           / Observation type
OBSERVER= 'R.Jeffries'         / Observers
DATE-OBS= '05/03/96'           / Date (dd/mm/yy) of observation
UTC     = '21:08:33.0'         / UTC of observation
MJDHDR  =        50147.8809256 / MJD of header creation
TELRA   = '00:49:36.10'        / Telescope right ascension (hours)
TELDEC  = '-28:01:45.5'        / Telescope declination (degrees)
TELEPOCH=               2000.0 / Epoch of telescope coordinates
ZD      =                 33.1 / Zenith distance (degrees)
HA      = '02:31:50.6'         / Hour angle (hours)
LST     = '03:20:54.7'         / Local sidereal time
OBSID   = 'ct15m.950706.014158.390 / Observation identification
AIRMASS =                1.193 / airmass
EXPTIME =                0.000 / Exposure time (sec)
DARKTIME=                0.170 / Dark time (sec)
COMMENT METEOROLOGICAL INFORMATION
ENVMJD  =          50147.87919 / Environment measurement time (MJD)
ENVWIN  =                  6.2 / Average wind speed (mph)
ENVDIR  =                   84 / Average wind direction (degrees)
ENVTEM  =                 19.4 / Site temperature (degrees C)
ENVHUM  =                   55 / Relative humidity (%)
ENVPRE  =                  783 / Air pressure (mbars)
COMMENT INSTRUMENT PARAMETERS
INSTRUME= 'cfccd   '           / Instrument
FILTER  = 'dia     '           / Filter in wheel one 
FILTYP  = 'diafragma'          / Full name of filter in wheel1
FILPOS  =                    1 / Filter system position
FILTER02= 'v       '           / Filter in wheel two
FTLTYP02= 'Vtek#2  '           / Full name of filter in  wheel2
FILPOS  =                    2 / Filter system position
TELFOCUS=                    0 / Telescope focus
DETSIZE = '[1:2048,1:2046]'    / Detector size

------------------- EHU 1 ------------------------------------------------------
XTENSION= 'IMAGE   '           / Image extension
BITPIX  =                   16 / Number of bits per pixel
NAXIS   =                    2 / Number of bits per pixel
NAXIS1  =                 1103 / Number of bits per pixel
NAXIS2  =                 2046 / Number of bits per pixel
INHERIT =                    T / Inherit global header
EXTNAME = 'im11    '           / Extension name
IMAGEID =                   11 / Image identification
PREFLASH=             0.000000 / Preflash time (secs)
CCDSUM  = '1 1     '           / CCD on-chip summing
CCDSEC  = '[1:1024,1:2046]'    / Region of CCD read
DATASEC = '[16:1039,1:2046]'   / Data section
TRIMSEC = '[16:1039,1:2046]'   / Trim section
BIASSEC = '[1050:1103,1:2046]' / Bias section
ARCONWF = 'Obs Tue Mar  5 17:34:11 1996' / Arcon wavefile
ARCONWM = 'MPP     '           / Waveform mode switches on
RDNOISE =                4.100 / Readout noise (e)
GAIN    =                3.300 / Amplifier gain (e/ADU)
ARCONGI =                    2 / Gain selection (index into Gain Table)
ARCONPRN=                4.100 / Predicted readout noise (e)
ARCONPG =                3.300 / Predicted gain (e/ADU)
AMPINTEG=                 7000 / Amplifier integration time (ns)

------------------- EHU 2 ------------------------------------------------------
XTENSION= 'IMAGE   '           / Image extension
BITPIX  =                   16 / Number of bits per pixel
NAXIS   =                    2 / Number of bits per pixel
NAXIS1  =                 1103 / Number of bits per pixel
NAXIS2  =                 2046 / Number of bits per pixel
INHERIT =                    T / Inherit global header
EXTNAME = 'im12    '           / Extension name
IMAGEID =                   12 / Image identification
PREFLASH=             0.000000 / Preflash time in secs
CCDSUM  = '1 1     '           / On chip summation (X,Y)
BIASSEC = '[1:54,1:2046]'      / Bias section
CCDSEC  = '[1025:2048,1:2046]' / Region of CCD read
DATASEC = '[65:1088,1:2046]'   / Data section
TRIMSEC = '[65:1088,1:2046]'   / Trim section
ARCONWF = 'Obs Tue Mar  5 17:34:11 1996' / Arcon wavefile
ARCONWM = 'MPP     '           / Waveform mode switches on
RDNOISE =                4.100 / Readout noise (e)
GAIN    =                3.200 / Amplifier gain (e/ADU)
ARCONGI =                    2 / Gain selection (index into Gain Table)
ARCONPRN=                4.100 / Predicted readout noise (e)
ARCONPG =                3.200 / Predicted gain (e/ADU)
AMPINTEG=                 7000 / Amplifier integration time (ns)

This section mapping is shown as currently done with Arcon to write the data in reverse order (i.e. flip) for the second amplifier. This results in the bias sections appearing on opposites sides in the two extensions. A new implementation might not flip the data in the controller which would give the following sections for the second extension with the CCDSEC keyword indicating the flip relative to the full image as defined by DETSIZE.

CCDSEC  = '[2048:1025,1:2046]' / Region of CCD read
DATASEC = '[16:1039,1:2046]'   / Data section
TRIMSEC = '[16:1039,1:2046]'   / Trim section
BIASSEC = '[1050:1103,1:2046]' / Bias section
Note that there is no sampling period indicated for the wind measurements which assumes that the measurements are 'instantaneous' at the time indicated. Other keywords that would be added are to specify the coordinate system and time system.