Program available at: http://www.imcce.fr/hosted_sites/naroo/program.html ; International audience ; The Cassini group within the Astronomy Unit at Queen Mary, University of London (QMUL) has been using the Imaging Science Subsystem (ISS) of the Cassini Spacecraft to make astrometric observations of the inner satellites and F ring of Saturn since 2004. Further observations are planned until the end of the mission in 2017. Here we summarize this work and describe how the astrometric data is stored in such a way that information from the GAIA catalogue can easily be used to reprocess the data without access to the images.