As discussed in chapter 3, the GRBM response matrices are also available in
FITS format.
Thus, after the specific data reduction and pre-analysis,
the two channels (40-100 and 100-700 keV) data for each temporal bin and
the 240 channels energy spectra
can be converted to FITS-OGIP spectra to be
analyzed with standard software packages like XSPEC and eventually fitted
simultaneously with WFC spectra (chapter 4).
While the response matrix conversion is more complex and needed the
development of specific IDL programs, the conversion of spectra from ASCII
files to FITS is more straightforward. This task is performed using
simple scripts based on FTOOLS programs. FTOOLS programs are also used
for simple arithmetical operations on the PHA files and to group the
data in order to achieve a number of counts per channel sufficient for
the application of the 
statistics.