TTYPE1  = 'TIME    '           / Mission Time in sec since 01 Jan 2021 00:00:00
TFORM1  = '1D      '           / data format of field
TUNIT1  = 's       '           / physical unit of field
TTYPE2  = 'COUNTS     '           / Pulse height amplitude
TFORM2  = 'string  '           / data format of field
TUNIT2  = 'counts'             / physical unit of field
TTYPE3  = 'SUMPHA  '           / Cumulative counts over all channels
TFORM3  = '1I      '           / data format of field
TUNIT3  = 'counts'             / physical unit of field
EXTNAME = 'ARRAY_PHA'           / Extension Name
TELESCOP= 'BURSTCUBE'          / Telescope mission name
INSTRUME= 'string'             / Instrument name
DATAMODE= 'string'             / Data mode
OBJECT  = 'string'             / Object name
RA_OBJ  = -99.0                / R.A. Object
DEC_OBJ = -99.0                / Dec Object
POSFLAG = -99                  / Position FLAG 1=good 0=best effort -1=false
EQUINOX = 2000                 / Equinox
RADECSYS= 'FK5'                / Coordinates Systems
OBS_ID  = 'yymmdd'             / Observation ID
MJDREFI =                59215 / MJD reference day 01 Jan 2021 00:00:00
MJDREFF =  0.00080074074074074 / MJD reference (fraction of day)
TIMEREF = 'LOCAL   '           / Reference Frame
TASSIGN = 'SATELLITE'          / Time assigned
TIMESYS = 'TT      '           / Time system
TIMEUNIT= 's       '           / Time unit for timing header keywords
TIMEPIXR=                    1 / Time stamps refer to the end of each bin
TIMEDEL = 0.0                  / Integration time
CLOCKAPP=                    F / If clock corrections are applied (T/F)
DATE-OBS= 'isodate'            / Start Date
DATE-END= 'isodate'            / Stop Date
TSTART  = 0.0                  / Start Time
TSTOP   = 0.0                  / Stop Time
TELAPSE = 0.0                  / TSTOP-TSTART in sec
ONTIME  = 0.0                  / Sum good time interval in sec
EXPOSURE= 0.0                  / Exposure
DEADAPP =                    F / if deadtime applied
TRIGGER = 0                    / Trigger number
TRIGTIME= 0.0                  / Trigger Time sec since 01 Jan 2021 00:00:00
TRIGUTC = 'isodate'            / TIME of Trigger time in UTC
TRIGDET = -99                  /Trigger Detector 0=no 1=yes
TRIGSCAL= 0.0                  /[s] Trigger timescale
TRIGSIGN= 0.0                  /Trigger significance
TRIGEMIN= 0.0                  / [keV] Trigger energy min
TRIGEMAX= 0.0                  / [keV] Trigger energy max
HDUCLASS= 'OGIP    '           / format conforms to the OGIP standard
HDUCLAS1= 'ARRAY   '           / hduclass1
HDUCLAS2= 'TOTAL   '           / hduclass2
ORIGIN  = 'GSFC    '           / Origin of the fits file
CREATOR = 'string'             / Software that create 1st the file
PROCVER = 'string'             / Processing version
CALDBVER= 'string'             / CALDB version
SEQPNUM = 1                    / Number of times the dataset has been processed
DATE    = 'isodate'            / File creation date
CHECKSUM= 'string'             / data unit checksum updated date
DATASUM = 'string'             / HDU checksum updated date
