Septentrio has announced that they have obtained, based on live ICD compliant Galileo messages from the four Galileo IOV satellites, a fi rst autonomous realtime Galileo PVT calculation. The standalone position was calculated from in-orbit navigation messages using a standard PolaRx4 GNSS receiver equipped with commercially released fi rmware. www.septentrio.com.
The PLAN Group of the University of Calgary was successful in capturing and processing the signals from these satellites as they emerged. Galileo PRN 11, 12, and 19 were found and tracked on E1B/C. The PLAN software GSNRx was also able to track simultaneously GPS L1 and GLONASS L1 and produce combined position solutions.
Examining the Galileo navigation message transmitted on the E1B signal, it was found that the satellite health status is fl agged as E1BHS=3 meaning Signal Component currently in Test, and the data validity status is fl agged as E1BDVS=1 meaning Working without Guarantee.
Data was collected using a roof-mounted NovAtel 702GG antenna and an inhouse two-channel digitizing front-end clocked by a high quality OCXO and also a three-channel National Instruments front-end for post-processing. The twochannel intermediate frequency data was streamed live to a laptop computer for real-time processing with GSNRx. Two RF channels were processed, the fi rst centered at 1574.0 MHz with an IF bandwidth of 10.0 MHz, for the GPS L1 C/A and Galileo E1B/C signals and the second centered at 1602.0 MHz again with a bandwidth of 10.0 MHz, for the GLONASS L1 OF signals. The GPS and GLONASS signals were tracked using a Kalmanfi lter-based tracking strategy while the Galileo signals were tracked using a specialized data-pilot algorithm.
Europe’s new age of satellite navigation has passed a historic milestone – the very fi rst determination of a ground location using the four Galileo satellites currently in orbit together with their ground facilities. This fundamental step confi rms the Galileo system works as planned.
“Once testing of the latest two satellites was complete, in recent weeks our effort focused on the generation of navigation messages and their dissemination to receivers on the ground,” explained Marco Falcone, ESA’s Galileo System Manager.
This first position fix of longitude, latitude and altitude took place at the Navigation Laboratory at ESA’s technical heart ESTEC, in Noordwijk, the Netherlands on the morning of 12 March, with an accuracy between 10 and 15 metres – which is expected taking into account the limited infrastructure deployed so far.