Apparently they didn't use a mobile atomic clock but a mobile gps clock to compare the times: http://operaweb.lngs.infn.it/Opera/publicnotes/note134.pdf http://

Apparently they didn't use a mobile atomic clock but a mobile gps clock to compare the times: http://operaweb.lngs.infn.it/Opera/publicnotes/note134.pdf http://operaweb.lngs.infn.it/Opera/publicnotes/note134.pdf So it appears they synchronized both timing sources with an orbiting clock, and the critique from this dutch guy seemingly stands.