Once you have seen which sources are detected by spiros, you can obtain better results by fixing the source positions in the image reconstruction. For example, you may want to fix the position of the bright, well known sources to see whether the detection significance of a fainter source improves (as it should in case of a real detection).
First, you may want to save the previous results. The easiest way is to make a full copy of your current working directory:
cd .. cp -r spi_analysis spi_imaging_without_catalogue cd spi_analysis
The source positions have to be provided to spiros through a source_cat.fits file. You can either use an existing file or create a new one with the catalogue extraction task (middle section of the main GUI). Here we explain how to produce a new source_cat.fits file including sources found in the ISDC reference catalogue in the observation FoV.