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Session A6: GNSS Integrity and Augmentation

Performance of DFMC SBAS Broadcasted from Japanese QZSS in Oslo, Norway
Toru Takahashi, Susumu Saito, Mitsunori Kitamura, and Takeyasu Sakai, ENRI, MPAT, Japan
Location: Beacon B

Peer Reviewed

Peer Reviewed

The aviation and maritime activities in the Arctic are growing with the recession of the Arctic sea ice. The Global Navigation Satellite System (GNSS), which are operating with the augmentation system such as the Satellite-based augmentation systems (SBAS) and Advanced Receiver Autonomous Integrity Monitoring (ARAIM), is effective for the navigation for the aviation and maritime in the Arctic because of poor infrastructures. However, the current L1 SBAS broadcasts augmentation messages from geostationary (GEO) satellites, which is not available practically in the polar region at a latitude of 72 degrees or higher.
Reid et al. (2016) estimated the availability of the different operations enabled by the SBAS and ARAIM using the MATLAB Algorithm Availability Simulation Tool (MAAST). They mentioned that the Dual-Frequency Multi-Constellation (DFMC) SBAS enables the aircraft precision approach as well as precise maritime operation.
The DFMC SBAS is under standardization by the International Civil Aviation Organization (ICAO). Broadcasting augmentation messages from the Inclined Geosynchronous Orbit (IGSO) satellite is considered as one of options. The Electronic Navigation Research Institute (ENRI) developed a DFMC SBAS prototype based on the draft standards (Kitamura et al., 2018). It can augment GPS, Galileo and GLONASS. The DFMC SBAS augmentation messages are generated based on the ground observation and broadcast from the Japanese Quasi-Zenith Satellite System (QZSS) for experiment. The QZSS, which currently includes three satellites in Quasi-Zenith Orbit (QZO) and one in GEO. The QZO is similar to IGSO but with a higher orbit eccentricity to stay longer at high elevation angles over Japan, i.e. with the apogee in the northern hemisphere. The inclination angle of the QZO is about 42 degrees. Thus, the DFMC SBAS could be available in the Arctic by using the message broadcast from QZSS.
To test DFMC SBAS in the polar region, we installed an experimental DFMC SBAS receiving system in Oslo, Norway (10.72 E, 59.94 N). Since Oslo is located on the other side of the earth from Japan, the QZSS signals are not always received there. Nevertheless, it is worthwhile testing in more challenging environment to validate DFMC SBAS broadcast from QZSS. Furthermore, European Geostationary Navigation Overlay Service (EGNOS) is available in Oslo, which enables us to compare our DFMC SBAS result with the EGNOS L1 services.
This system consisted of an antenna and two receivers. The antenna used was a JAVAD GrAnt-G3T capable of receiving signals L1, L2, and L5 bands. The DFMC GNSS measurements were recorded by a JAVAD DELTA receiver. A Furuno prototype DFMC SBAS receiver is used to record DFMC SBAS messages. This experiment was conducted continuously from 24 February 2021 to 17 March 2021. The antenna and receivers were installed on the roof of the Chemistry building of University of Oslo. QZSS satellites appeared in the north-eastern sky from Oslo with the maximum elevation angle of 15 degrees. We successfully received the DFMC SBAS messages from QZSS by the Furuno prototype DFMC receiver. GPS, Galileo, GLONASS, and BeiDou signals were recorded by JAVAD DELTA. We analyzed the errors in the position solutions as well as vertical and horizontal protection levels by using GPS L1/L5 and Galileo E1/E5a signals augmented by the DFMC SBAS. Potential performances of the DFMC SBAS in higher latitude regions will also be discussed.
References:
M. Kitamura, T. Aso, T. Sakai (2018) Wide Area Augmentation Performance of DFMC SBAS Using Global Monitoring Stations, The 16th IAIN World Congress 2018.
Reid, T., Walter, T., Blanch, J., and Enge, P. (2016) GNSS Integrity in The Arctic. J Inst Navig, 63: 469– 492. doi: 10.1002/navi.169.



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