A prototype for a Multi-GNSS orbit combination

Since 1994, the International GNSS Service (IGS) provides a combination of orbit and clock offset products from its different Analysis Centers. These products are used as input by many software for countless scientific and/or operational applications. They can also be used as an independent reference for benchmark experiments. Nevertheless, those products include GPS-only data, despite the fact that nowadays several GNSS constellations are available. We performed modifications on the existing IGS combination software and made it compatible with multi-GNSS products. We present here the results of a combination of five Multi-GNSS Experiment Analysis Centers (ACs) for five constellations (GPS + GLONASS + Galileo + Beidou + QZSS) from GPS week 1800 to 2000. The RMS of combined orbit w.r.t. input ACs ones are ~ 3±1.5cm for recent weeks of the test period.