XTENSION  = 'IMAGE' /        FITS extension type
BITPIX    = 16      /        bits per data value
NAXIS     = 4       /        number of data array dimensions
PCOUNT    = 0       /        number of parameter bytes following data table
GCOUNT    = 1       /        number of groups
EXTNAME   = 'SCI'   /        extension name
BSCALE    = 1.0     /        scale factor for array value to physical value
BZERO     = 32768   /        physical value for an array value of zero
BUNIT     = 'DN'    /        physical units of the data array values
