1. 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

2. 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 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

3. 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.

4. 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

5. 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
・ 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.

6. 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
Positioning
Complement GPS 
L1C
L1S
Augmentation (SLAS)
QZSS Service
Messaging
　QZSS Service
L1Sb
Augmentation
(SBAS)
SBAS (L1) Service —
L2C
L5 I/Q
L5S
Experimental Use (L5 SBAS)
SBAS (L5) Service　
L6D (D1)
Augmentation (CLAS)
L6E (D2)
Experimental Use (MADOCA)

7. 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.

8. 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
Hawaii and Australia reference sites are
removed in Feb
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.

9. 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

10. 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.

11. 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

12. Prototype DFMC SBAS 13 Monitor Stations
GPS/GNSS Symposium, Nov. 2017
Prototype DFMC SBAS
13 Monitor Stations
Dual Frequency
DFMC L5 SBAS
Location:
GEONET
(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.

13. 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 Wakayama.
Confirmed stable performance for a year; Horizontal ~0.5m and Vertical ~1m.

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

15. 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
Electronic Navigation Research Institute
National Institute of Maritime, Port and Aviation Technology, Japan