Event energy correction

Since the start of the second revision of the ISDC processing, sets of gain coefficient files are part of the analysis input data. For each revolution, a dedicated ISDC pipeline (1) builds spectra from all available events, (2) derives the positions of a number of background lines, and (3) compute gain coefficients by fitting a polynomial to the line position - energy relation (see Sect.  for more details). The ``spi_science_analysis'' pipeline uses these files by default for on-the-fly energy correction, in the event binning step (program spi_obs_hist).

This ``standard'' energy correction is excellent for most cases, even for line analysis (only line analysis in revolutions with large temperature changes may require better correction). You can however apply your own set of gain coefficients by providing the name of an alternative index of gain coefficient files in the ``Gain Coefficient file name'' entry field of the spi_science_analysis GUI (click on the upper right ``hidden'' button to find this parameter).