000004214 001__ 4214
000004214 005__ 20190508174507.0
000004214 037__ $$aCTALK-2019-0115
000004214 100__ $$aSignorile, Giovanna
000004214 245__ $$aGalileo and GNSS Time Offsets
000004214 260__ $$c2018
000004214 269__ $$c2018-04-11
000004214 520__ $$aSince April 2013, Galileo started to disseminate the GPS to Galileo Time Offset (GGTO), by transmitting the conversion parameters through the navigation message. This broadcast offset is allowing the user of a combined GSP/Galileo receiver to achieve a unique navigation solution by using measurements from both GPS and Galileo satellites, thus  allowing interoperability between the two navigation satellite systems. Nowadays, many positioning systems are available, the topic of interoperability is therefore   crucial to provide better capabilities at user level than the ones that would be achieved by relying solely on one system. The time offsets between the different systems should therefore be made available to the multi-GNSS users. An alternative would be that each constellation broadcast the time offset between its time scale and a reference common to all GNSS.  In this paper, we investigate this scenario. We propose, as reference common to all GNSS, either a combination of the predictions of the GNSS time scales of the different systems, or directly the UTC predictions broadcast by the different systems. The link between this common GNSS reference time scale and BIPM is also investigated. From these approaches, we present a first assessment of the performances that can be achieved by a single user equipped with a not calibrated multi-GNSS receiver when estimating the offset between Galileo and other GNSS time scales, therefore addressing the interoperability of Galileo with other GNSS.
000004214 594__ $$aNO
000004214 700__ $$aSesia, Ilaria,
000004214 700__ $$aDefraigne, Pascale
000004214 700__ $$aTavella, Patrizia
000004214 773__ $$t32nd European Frequency and Time FOrum
000004214 8560_ $$fpascale.defraigne@observatoire.be
000004214 906__ $$aContributed
000004214 980__ $$aCTALKCONT