The first step of the analysis is to create the Observation Group (for more information on og_create, see ). The easiest is to launch the first program from the analysis top-level directory (i.e., $REP_BASE_PROD) so that the parameter ``baseDir'' can be set to the current directory.
og_create idxSwg=spi.lst ogid=spi_analysis baseDir="./" instrument=SPI
``spi.lst'' is the file containing the list of pointing DOLs created as explained in Sect. . Note that if this file is located in another directory, the full path should be specified together with its name. The ``spi_analysis'' term is a user chosen parameter used to name the subdirectory where all analysis data will be stored. ``instrument=SPI'' should never be changed for SPI data analysis. The result is an observation group named ``og_spi.fits'' located in ``./obs/spi_analysis/''. This later location is where the following of your analysis should be executed, and where all further analysis results will be written.
Depending on the number of science windows, the speed of your machine, and your data server, this can take from a few seconds for just one science window to more than an hour for hundreds of science windows (and of the order of a few seconds for this example).