The INSTISIS packet

The INSTISIS packet lists the header information required for any observation with either of the arms of ISIS or with FOS. The header records required should be as follows:

CENWAVE = REAL               / Approx central wavelength (A)      *
LINESMM = REAL               / Number of lines/mm of the grating  *
DISPERSI= REAL               / Nominal dispersion (A/mm)          *
ISIANAMO= CHAR               / Position of anamorphotic lens
ISIHWAVE= CHAR               / Position of half-wave polarizer
ISIQWAVE= CHAR               / Position of quarter-wave polarizer
ISIDEKKE= CHAR               / Position of dekker
ISISLITU= CHAR               / Slit unit (long, multi or fibre)
ISISLITW= INTEGER            / Slit width (microns)
PAOFFSET= REAL               / Slit p.a. - tel. p.a. (degs)
ISIFCP  = CHAR               / Field-lens, calcite, polaroid or clear
ISIBFOLD= CHAR               / Position of blue fold
ISIRFOLD= CHAR               / Position of red fold
ISISARM = CHAR               / Data from red arm, blue arm or FOS ?
ISIFILTA= CHAR               / Name of filter A in ISIS arm      *
ISIFILTB= CHAR               / Name of filter B in ISIS arm      *
ISIHART = CHAR               / Configuration of Hartmann shutter *
ISICOLL = INTEGER            / Position of collimator (microns)  *
ISIGRAT = CHAR               / Name of grating                   *
ISITHETA= INTEGER            / Angle of grating (mdegs)          *
ISIBXDIS= CHAR               / Position of blue x disperser
ISITIGHT= CHAR               / Light tight ?
ISISDOOR= CHAR               / Status of slit door
ISICELL = CHAR               / State of grating-cell clamps      *
ISIGDOOR= CHAR               / Status of grating door
ISILID  = CHAR               / Status of ISIS lid
PAOFFSET= REAL               / Slit p.a. - telescope p.a. (degrees)

Notes:

• The header information specific to a particular ISIS arm (marked above with an asterisk) will be obtained from different noticeboard locations depending on the arm, and should not be written at all if the data is from FOS. The red arm filters are in the FOS light path, and so this information should be collected for FOS observations.