The path between accumulation and reduction steps is not necessarily a regular pipeline, but it can be an iterative and interactive process with a feedback loop between steps. Response matrix generation is a further step necessary for spectral analysis of SAX data and for data deconvolution purposes. Programs to generate the response matrix of the experiments onboard SAX, appropriate to the observations under analysis, using calibration and housekeeping data and particular instrument settings, are part of the SAX scientific software. SAX reduced data will be then available in the specific XAS format as well as in FITS form. FOT filing is the first step of the data reduction phase.
Accumulation is the second step of the data reduction phase.
Cross-accumulation programs are experiment independent and they mainly deal with list of photons to produce other reduced data structures as, for example, to create an image from a photon list with selection in energy and time windows, simultaneously. Reduction proper is strictly related to the instrument specific accumulations, and it only depends on experiment specific functions, as dead time correction, background subtraction, point spread function correction, and so on. The result of this step can obviously advise the observer to go back and to repeat the accumulation step, along an iterative and interactive process. The XAS format can be immediately mapped to FITS format. Response matrix generation programs are also part of the XAS software.