準天頂衛星L5S信号によるDFMC SBAS実験 GPS/GNSSシンポジウム 東京海洋大学（江東区） Nov. 9, 2017 OS1-2 準天頂衛星L5S信号によるDFMC SBAS実験 坂井 丈泰・麻生 貴広・北村 光教 海上・港湾・航空技術研究所

Introduction QZSS (Quasi-Zenith Satellite System) Program GPS/GNSS Symposium, Nov. 2017 Introduction QZSS (Quasi-Zenith Satellite System) Program Regional navigation service broadcast from high-elevation angle by a combination of three satellites on the inclined geosynchronous (quasi-zenith) orbit and a GEO. The first satellite “Michibiki” launched in 2010 has been continuously broadcasting GPS-like ranging signals and some augmentation signals. Begins the operation with 4-satellite constellation in April 2018, and 7-satellite constellation will follow around 2023. QZS-2 was just launched on 1 June, 2017. The mission of the operational QZSS: Positioning: Ranging and augmentation services including SBAS; and Messaging: Two-way mobile communication service for disaster and crisis management. QZSS L-Band Ranging Signals GPS-like ranging signals: L1C/A, L2C, L5 I/Q, and L1C Augmentation signals: L1S, L5S, and L6 D/E for QZS-2/3/4 plus L1Sb for QZS-3 Planning to use L5S signals for DFMC SBAS experiment. L5 SBAS transmission from GEO by QZS-3 and from IGSO by QZS-2/4

QZSS Concept Broadcast signal from high elevation angle. GPS/GNSS Symposium, Nov. 2017 QZSS Concept GEO IGSOs QZSS-IGSO GPS/GEO Broadcast signal from high elevation angle. Applicable to navigation services for mountain area and urban canyon. Augmentation signal from the zenith could help users to acquire and augment other GNSS satellite signals at any time. IGSO (Inclined Geosynchronous Orbit) centered at 139E. Eccentricity 0.075, inclination 41deg. Additional GEO.

Mission Mission 1: Positioning Services: Mission 2: Messaging Service: GPS/GNSS Symposium, Nov. 2017 Mission Mission 1: Positioning Services: Ranging Service: Broadcasts GPS-like ranging signals on three frequencies (L1C/A, L2C, L5I/Q, and L1C) to improve availability of navigation in urban and mountain areas. Submeter Level Augmentation Service: SLAS on L1S: Code-phase differential correction service for mobile users. Centimeter Level Augmentation Service: CLAS on L6D: Carrier-phase differential correction service for precision applications. SBAS Service by QZS-3 GEO: Using L1Sb signal. Mission 2: Messaging Service: Provides two-way mobile communication service for disaster and crisis management. S-band two-way communication for emergency safety report. Downlink short messages on L1 frequency. (C)JAXA QZSS Orbit and Ground Track

Contour of QZSS Minimum Elevation Angle GPS/GNSS Symposium, Nov. 2017 4-Satellite Const. in 2017 QZS Visibility Inside Japanese Territory ・ 2 to 3 IGSOs above 20 deg. elevation; ・ At least 1 IGSO above 60 deg. elevation. Equator GEO @127E ・ Improved visibility ・ Additional services Quasi-Zenith Orbit (IGSO) Contour of QZSS Minimum Elevation Angle Now we have QZS-1, -2, and -3 satellites on orbit; 2 IGSO and 1 GEO. One more IGSO satellite, QZS-4, will be launched by Fall 2017.

QZSS Ranging Signals Signal Frequency MHz Service Compatibility QZS-1 GPS/GNSS Symposium, Nov. 2017 QZSS Ranging Signals Signal Frequency MHz Service Compatibility QZS-1 QZS-2/4 QZS-3 IGSO GEO L1C/A 1575.42 Positioning Complement GPS  L1C L1S Augmentation (SLAS) QZSS Service Messaging 　QZSS Service L1Sb Augmentation (SBAS) SBAS (L1) Service — L2C 1227.60 L5 I/Q 1176.45 L5S Experimental Use (L5 SBAS) SBAS (L5) Service　 L6D (D1) 1278.75 Augmentation (CLAS) L6E (D2) Experimental Use (MADOCA)

SBAS Service Satellite-Based Augmentation System: GPS/GNSS Symposium, Nov. 2017 SBAS Service Satellite-Based Augmentation System: GNSS augmentation system primarily for aviation use International standard adopted by ICAO (Int’l Civil Aviation Organization). Provides augmentation to ensure integrity and accuracy for civil aviation. Operational systems: US WAAS (Wide Area Augmentation System) since 2003. Japanese MSAS (MTSAT-based Augmentation System) since 2007. European EGNOS (European Geostationary Overlay Service) since 2011. Indian GAGAN (GPS-Aided Geo-Augmented Navigation) since 2014. Planned systems: Russian SDCM, Korean KASS, Chinese BDSBAS, etc. Current Standard: L1 SBAS Augmentation information transmitted from the SBAS satellite L1 C/A signal with PRN 120 to 158 transmitted from GEO SFSC: Single-Frequency and Single-Constellation Augments L1 C/A only; Augments GPS or GLONASS. Transmits ionospheric correction as the vertical delay at grid points. Limited performance at the low latitude regions… Due to ionospheric irregularities and limited number of GNSS satellites.

MSAS Program MSAS: Japanese SBAS in operation. GPS/GNSS Symposium, Nov. 2017 MSAS Program (c) Mitsubishi Electric Corp. MSAS GEO: MTSAT-2 MSAS: Japanese SBAS in operation. Operational since Sept. 27, 2007. 2 GEO: MTSAT-1R and MTSAT-2. Continues operation with 2 signals via 1 GEO. MTSAT-1R decommissioned in Dec. 2015. Hawaii and Australia reference sites are removed in Feb. 2015. Service for Air Navigation GPS Augmentation Information for RNAV, from En-route through NPA (RNP 0.3 performance). Within Fukuoka (Japanese) airspace. Only horizontal navigation due to ionosphere activities. Renewal in 2020: MSAS V2 QZS-3 GEO will take over the current GEO MTSAT-2. The current GEO will be decommissioned in 2020. 13 reference stations; 7 stations added to the current configuration. Update for vertical guidance capability planned around 2023: MSAS V3 Vertical guidance service with 2 GEO.

Near-Term Plan Service SBAS Service by QZS-3 Service Fiscal Year 2015 GPS/GNSS Symposium, Nov. 2017 Near-Term Plan Fiscal Year 2015 2016 2017 2018 2019 2020 2021 2022 2023 and Later 1st Michibiki QZSS 4-Satellite Constellation 7-Satellite Replenish Satellite Launch #1-R Experiment/Test Launch　#2,3,4 Service Current MSAS Service by MTSAT-2 SBAS　Service by QZS-3 Development/Launch (Additional 3 satellites) Service

DFMC SBAS Trial Dual-Frequency operation: MSAS V4 GPS/GNSS Symposium, Nov. 2017 DFMC SBAS Trial Dual-Frequency operation: MSAS V4 DFMC SBAS transmitted on L5 frequency: L5 SBAS Following L1 single frequency single constellation SBAS. Eliminates ionospheric effects dramatically thanks to dual frequency operation. Vertical guidance service everywhere in the coverage. QZS-2 and later satellites have the L5S signal. L5S signal of QZS-2 to -4 is compliant with the L5 SBAS with a few exception. ENRI is now conducting DFMC SBAS Trial with QZSS L5S The First L5 SBAS experiment with real L5 signal from the space. Both GEO (QZS-3) and IGSO (QZS-2/4) are used for this trial. ENRI has developed the prototype SBAS for this trial. GPS/GLONASS/Galileo-capable dual frequency SBAS. Compliant with the draft international standard of L5 DFMC SBAS. Began the trial on 23 Aug. using L5S signal (PRN 196) of QZS-2 IGSO. Additional signals from QZS-3 and QZS-4 by the end 2017. Expects participation to this experiments.

Configuration for Trial GPS/GNSS Symposium, Nov. 2017 Configuration for Trial QZSS #2, #3, and #4 GLONASS GPS Galileo GEO (QZS-3) + IGSO (QZS-2/4) Ranging Signal L5S Signal L5S Signal Uplink BeiDou Measurement Data L5 SBAS Message GEONET ENRI L5 SBAS Prototype QZSS C&C GSI (Shinjuku, Tokyo) ENRI, MPAT (Chofu, Tokyo) QZSS MCS (Hitachi-Ota, Ibaraki) Supports DFMC Provides measurements in real time Operates in real time Supports GPS, GLONASS, and Galileo Control of QZSS Handles L5S message data

Prototype DFMC SBAS 13 Monitor Stations GPS/GNSS Symposium, Nov. 2017 Prototype DFMC SBAS 13 Monitor Stations Dual Frequency DFMC L5 SBAS Location: GEONET 950369 (Wakayama) Period: 2016/12/15 (24H) SBAS corrections improve position accuracy in both modes of GPS and GPS+GLONASS. SBAS messages are generated by the prototype DFMC SBAS developed by ENRI, in accordance with the draft DFMC L5 SBAS standards.

Prototype DFMC SBAS Horizontal Accuracy Vertical Accuracy GPS/GNSS Symposium, Nov. 2017 Prototype DFMC SBAS w/o augmentation w/ augmentation Horizontal Accuracy Vertical Accuracy Evaluated long-term performance using archive data at GEONET 950369 Wakayama. Confirmed stable performance for a year; Horizontal ~0.5m and Vertical ~1m.

Clock/Orbit Correction GPS/GNSS Symposium, Nov. 2017 Realtime Experiment Clock/Orbit Correction Position Solution Monitored Satellites Satellites in Sky Output Message Stream

Conclusion QZSS: Japanese Regional Satellite Navigation System GPS/GNSS Symposium, Nov. 2017 Conclusion QZSS: Japanese Regional Satellite Navigation System Services: GPS-complement ranging, GNSS augmentation, and Messaging. L1 SBAS service by L1Sb signal: Single-Frequency Single-Constellation. 4-satellite constellation including 3 IGSO and a GEO in 2017. Will be extended to 7-satellite constellation around 2023. DFMC SBAS Trial Using QZSS L5S Augmentation Signal The First L5 SBAS experiment with real L5 signal from the space. ENRI has developed the prototype SBAS for this trial. GPS/GLONASS/Galileo-capable dual frequency SBAS. Compliant with the draft int’l standard of L5 DFMC SBAS. The trial has been conducted since 23th of August, 2017. Report if you receive the signal on PRN 196. Contact for more information: Dr. Takeyasu Sakai <sakai@mpat.go.jp> Electronic Navigation Research Institute National Institute of Maritime, Port and Aviation Technology, Japan