Data model: proc-gimg

General description: Raw guider images are processed at APO, resulting in prog-gimg files. See Processed Guider Images at APO for further information.

Naming convention: proc-gimg-[DDDD].fits, The four digits look like some kind of timestamp but bear no resemblance to the times in the headers. Probably they are simply a sequence number.

Approximate size: 864000 bytes.

File type: FITS

Read by products: ???

Written by products: ???

Sample Header (HDU 0):

SIMPLE  =                    T / conforms to FITS standard
BITPIX  =                   16 / array data type
NAXIS   =                    2 / number of array dimensions
NAXIS1  =                  512
NAXIS2  =                  512
EXTEND  =                    T
IMAGETYP= 'object  '
EXPTIME =                 10.0
TIMESYS = 'TAI     '
DATE-OBS= '2009-11-11 02:41:37.4Z' / start of integration
CCDTEMP =           -40.099995 / degrees C
FILENAME= '/data/gcam/55146/gimg-0200.fits'
OBJECT  = 'gimg-0200'
DARKFILE= '/data/gcam/55145/gimg-0004.fits'
FLATFILE= '/data/gcam/55146/gimg-0178.fits'
FLATCART=                   11
BEGX    =                    0
BEGY    =                    0
BINX    =                    1
BINY    =                    1
CRVAL1  =                    0 / (output) Column pixel of Reference Pixel
CRVAL2  =                    0 / (output) Row pixel of Reference Pixel
CRPIX1  =                  0.5 / Column Pixel Coordinate of Reference
CRPIX2  =                  0.5 / Row Pixel Coordinate of Reference
CTYPE1  = 'LINEAR  '           / Type of projection
CUNIT1  = 'PIXEL   '           / Column unit
CUNIT2  = 'PIXEL   '           / Row unit
SDSSFMT = 'GPROC 1 2'          / type major minor version for this file
IMGBACK =               1821.0 / crude background for entire image. For displays
SEEING  =    1.733515205482617 / Estimate of current seeing, arcsec fwhm
GCAMSCAL=                0.026 / guide camera plate scale (mm/pixel)
PLATSCAL=             217.7358 / plug plate scale (mm/degree)
OBJSYS  = 'ICRS    '           / The TCC objSys
RA      =           346.000329 / RA of telescope boresight (deg)
DEC     =             0.001893 / Dec of telescope boresight (deg)
RADEG   =                346.0 / RA of telescope pointing(deg)
DECDEG  =                  0.0 / Dec of telescope pointing (deg)
ROTTYPE = 'Obj     '           / Rotator request type                               --------------------------------
ROTPOS  =                  0.0 / Rotator request position (deg)                     Ask Russell
BOREOFFX=                  0.0 / TCC Boresight offset, deg
BOREOFFY=                  0.0 / TCC Boresight offset, deg
ARCOFFX =             0.000329 / TCC ObjArcOff, deg
ARCOFFY =             0.001893 / TCC ObjArcOff, deg
OBJOFFX =                  0.0 / TCC ObjOff, deg
OBJOFFY =                  0.0 / TCC ObjOff, deg
CALOFFX =                  0.0 / TCC CalibOff, deg
CALOFFY =                  0.0 / TCC CalibOff, deg
CALOFFR =                  0.0 / TCC CalibOff, deg
GUIDOFFX=                  0.0 / TCC GuideOff, deg
GUIDOFFY=                  0.0 / TCC GuideOff, deg
GUIDOFFR=             0.019667 / TCC GuideOff, deg
AZ      =                2.222 / Azimuth axis pos. (approx, deg)
ALT     =               57.284 / Altitude axis pos. (approx, deg)
IPA     =              181.833 / Rotator axis pos. (approx, deg)
SPA     =    1.642730458961487 / TCC SpiderInstAng
FOCUS   =               491.23 / User-specified focus offset (um)
M2PISTON=               996.71 / TCC SecOrient
M2XTILT =                -3.98 / TCC SecOrient
M2YTILT =   -8.960000000000001 / TCC SecOrient
M2XTRAN =                10.17 / TCC SecOrient
M2YTRAN =                77.39 / TCC SecOrient
M1PISTON=              -790.01 / TCC PrimOrient
M1XTILT =                -3.04 / TCC PrimOrient
M1YTILT =                 5.26 / TCC PrimOrient
M1XTRAN =               277.25 / TCC PrimOrient                                     Ask Russell
M1YTRAN =               178.07 / TCC PrimOrient                                   ---------------------------
SCALE   =              1.00008 / User-specified scale factor    **2.5 Telescope scale factor to match project sky on focal plane
FF      = '0 0 0 0 '           / FF lamps 1:on 0:0ff
NE      = '0 0 0 0 '           / NE lamps 1:on 0:0ff
HGCD    = '0 0 0 0 '           / HGCD lamps 1:on 0:0ff
FFS     = '0 0 0 0 0 0 0 0'    / Flatfield Screen 1:closed 0:open
NAME    = '3564-55145-01'      / The name of the currently loaded plate
PLATEID =                 3564 / The currently loaded plate
CARTID  =                   11 / The currently loaded cartridge
MAPID   =                    1 / The mapping version of the loaded plate
POINTING= 'A       '           / The currently specified pointing
DRA     = 5.666343482725871E-06 / measured offset in RA, deg            **by how much the guider thinks the telescope is wrong
DDEC    = 1.981334345452099E-05 / measured offset in Dec, deg                  "
DROT    = 0.0003566108349008755 / measured rotator offset, deg                 "
DFOCUS  =   -8.278618687226965 / measured focus offset, um                      "
DSCALE  = 2.031682903707919E-05 / measured scale offset, %                     "
FILTRA  = -3.399806089635522E-06 / filtered offset in RA, deg               **measured offsets modified by PID loop coeffs
FILTDEC = -1.188800607271259E-05 / filtered offset in Dec, deg                    "
FILTROT = -0.0001783054174504378 / filtered rotator offset, deg                   "
FILTFCUS=   0.8278618687226965 / filtered focus offset, um                          "
FILTSCLE= -1.01584145185396E-05 / filtered scale offset, %                          "
OFFRA   = -3.399806089635522E-06 / applied offset in RA, deg              **offsets actually applied, typically same as filtered value unless correction is off
OFFDEC  = -1.188800607271259E-05 / applied offset in Dec, deg                  "
OFFROT  = -0.0001783054174504378 / applied rotator offset, deg                 "
OFFFOCUS=   0.8278618687226965 / applied focus offset, um                       "
OFFSCALE=                  0.0 / applied scale offset, %                                         "
END

HDU 1: The bitmask image for image 0

XTENSION= 'IMAGE   '           / Image extension
BITPIX  =                    8 / array data type
NAXIS   =                    2 / number of array dimensions
NAXIS1  =                  512
NAXIS2  =                  512
PCOUNT  =                    0 / number of parameters
GCOUNT  =                    1 / number of groups

HDU 2: guide fiber rotated images nominally 16 for BOSS

XTENSION= 'IMAGE   '           / Image extension
BITPIX  =                   16 / array data type
NAXIS   =                    2 / number of array dimensions
NAXIS1  =                   19
NAXIS2  =                  285
PCOUNT  =                    0 / number of parameters
GCOUNT  =                    1 / number of groups

HDU 3: guider rotated masks

XTENSION= 'IMAGE   '           / Image extension
BITPIX  =                    8 / array data type
NAXIS   =                    2 / number of array dimensions
NAXIS1  =                   19
NAXIS2  =                  285
PCOUNT  =                    0 / number of parameters
GCOUNT  =                    1 / number of groups

HDU 4: nominally 2 acquisition fibers for BOSS

XTENSION= 'IMAGE   '           / Image extension
BITPIX  =                   16 / array data type
NAXIS   =                    2 / number of array dimensions
NAXIS1  =                   59
NAXIS2  =                  118
PCOUNT  =                    0 / number of parameters
GCOUNT  =                    1 / number of groups
END

HDU 5: masks for acquisition fibers for BOSS

XTENSION= 'IMAGE   '           / Image extension
BITPIX  =                   16 / array data type
NAXIS   =                    2 / number of array dimensions
NAXIS1  =                   59
NAXIS2  =                  118
PCOUNT  =                    0 / number of parameters
GCOUNT  =                    1 / number of groups
END

HDU 6: A binary table containing information about the guide probes and guide stars. Each entry is for one guide probe; data is listed in probe number order (starting from 1).

XTENSION= 'BINTABLE'           / binary table extension
BITPIX  =                    8 / array data type
NAXIS   =                    2 / number of array dimensions
NAXIS1  =                   99 / length of dimension 1
NAXIS2  =                   17 / length of dimension 2
PCOUNT  =                    0 / number of group parameters
GCOUNT  =                    1 / number of groups
TFIELDS =                   24 / number of table fields
TTYPE1  = 'exists  '
TFORM1  = 'L       '
TTYPE2  = 'enabled '
TFORM2  = 'L       '
TTYPE3  = 'flags   '
TFORM3  = 'L       '
TTYPE4  = 'xFocal  '
TFORM4  = 'E       '
TTYPE5  = 'yFocal  '
TFORM5  = 'E       '
TTYPE6  = 'xCenter '
TFORM6  = 'E       '
TTYPE7  = 'yCenter '
TFORM7  = 'E       '
TTYPE8  = 'radius  '
TFORM8  = 'E       '
TTYPE9  = 'xFerruleOffset'
TFORM9  = 'E       '
TTYPE10 = 'yFerruleOffset'
TFORM10 = 'E       '
TTYPE11 = 'rotation'
TFORM11 = 'E       '
TTYPE12 = 'rotStar2Sky'
TFORM12 = 'E       '
TTYPE13 = 'focusOffset'
TFORM13 = 'E       '
TTYPE14 = 'fiber_type'
TFORM14 = '20A     '
TTYPE15 = 'xstar   '
TFORM15 = 'E       '
TTYPE16 = 'ystar   '
TFORM16 = 'E       '
TTYPE17 = 'dx      '
TFORM17 = 'E       '
TTYPE18 = 'dy      '
TFORM18 = 'E       '
TTYPE19 = 'dRA     '
TFORM19 = 'E       '
TTYPE20 = 'dDec    '
TFORM20 = 'E       '
TTYPE21 = 'fwhm    '
TFORM21 = 'E       '
TTYPE22 = 'poserr  '
TFORM22 = 'E       '
TTYPE23 = 'stampSize'
TFORM23 = 'I       '
TTYPE24 = 'stampIdx'
TFORM24 = 'I       '
END