Introduction to Michibikiand EWS
GNSS Applications for Policy and Decision Makers in theContext of Nepal
July 13, 2021
Satoshi Kogure
National Space Policy Secretariat
Cabinet Office, Government of Japan

Contents
QZSS, “Michibiki” Overview

1.
••

•

Future Expansion to 7SV constellation

2.
•

3.

SystemServices and Performances
Program schedule

Service expansion into Asia Pacific region

Summary1

1. QZSS Overview -System◼ Constellation:

QZS-1

QZS-2, 4

 1 GEO Satellite, 127E
 3 QZO Satellite (IGSO)◼ Ground System

QZS-3

Equator 2 Master ControlStations◼ Hitachi-Ota and Kobe

 7 Satellite TTC Stations

QZSS Control Center, Hitachi-Ohta,◼ Located south-westernislands Over 30 Monitor Stations

around the world2

1. QZSS Overview -Current Services◼ Functional Capabilities:
 GPS Complementary (Ranging signals)
 GNSS Augmentation (Error corrections) Messaging Service (Disaster relief, management)◼ Coverage: Asia and Pacific region
 Augmentation service covers only Japan◼

Experimental service provides error corrections in Asia Pacific region

4050
60
QZSS-1

10QZSS-2
QZSS-4
QZSS-3(127E)

One or more QZSS SVs over 10 degrees elevation angle

3

1. QZSS Overview -Current Services▌Service Area of SLAS

monitoring station:
SapporoSendai
Hitachi-ohta
Komatsu
KobeHiroshima
Fukuoka
Tanegashima
Amami
ItomanMiyako-jimaIshigaki-jima
Chichi-jima▌Accuracy of SLAS

Service Area is the area surrounded by the red line.
The left-axis is latitude, and lower-axis is longitude.

positioning errorm(95%)
horizontal
vertical≤ 1.0 m≤ 2.0 mRemarks
EL mask : 10°
User range error caused by user’s receivers anduser’s situation : 0.87 m(95%)
41. QZSS Overview -Current ServicesOverview of CLAS (Centimeter Level Augmentation Service)
Quasi-Zenith Satellite System(QZSS: JPN)

GNSS

Positioning Signal
Altitude
500km③Broadcast via satellite(or on ground communication)①Error in Positioning
Signals
Orbit clock, Biases,Ionosphere,Troposphere④②Create augmentation dataand compress④ Positioning errors
corrected byeach receiver
CORS(Continously Operationg
Reference Station)

Server and facility
for CLAS

Users

Specification on positioning accuracy
H ≤ 6.0 cm (95%), V ≤ 12.0 cm (95%) (Static)
H ≤ 12.0 cm (95%), V ≤ 24.0 cm (95%) (Kinematic)5

1. QZSS Overview -Current ServicesFunctional Capability 3 Messaging Services
Satellite Report for Disaster and Crisis Management (DC Report)
QZSS

Disaster Info. provided by JMA suchas Tsunami, Volcanic eruption,
weather warning and so on.

⚫ Using margin of L1S signal⚫ Same service coverage as GPS
complementary service
Using one of four slots of L1S:1575.42MHz,
once a four seconds, 250 bits short code cantransmits disaster management info withapplicable location
DC Report available Handset(GNSS Rx, Car Navigation device)

Disaster Info.

Japan
MeteorologicalAgency (JMA)

Ground Control
Segment

Rx can select the Info which shown the devices
depending on their location

6

1. QZSS Overview -Development PlanQZSS Program Schedule (latest)JFY

1st Michibiki

20152016

2017

2018

2019

2020

2021

2022

2023～

Replacement of Michibiki
Launch No.1R
satellite

In-Operation
Launch No.2,3,4

QZSS
4-Sat.
Constellation

QZSS
7-Sat.
Constellation

QZSS Service
Official Service Launchon Nov 1, 2018

SBAS Service

Development / Design (Additional 3 Sats.)

QZSS Service

Today
7

2. QZSS 7SV Constellation Design▌QZSS Constellation Plan

QZS-5
QZS-5
QZS-1RQZS-1R
North pole
QZS-3

QZS-6(GEO)

QZS-3(GEO)

QZS-6
QZS-7

QZS-2

QZS-2
QZS-4

QZS-4

QZS-7(QGEO)South poleOrbit

SV

Center Longi.
(deg.)

GEO(2-sats)

QZS-3, 6

127E, 90.5E

QZO(4-sats)

QZS-1R,QZS-2, 4, 5

148E(nom)
139E(nom)

QGEO(1-sat)

QZS-7

185E(nom)

7-QZSS Ground Track*QGEO: Quasi Geostationary Earth Orbit(i>1deg, e=0.008)

8

2. QZSS 7SV Constellation Design▌QZSS Constellation Plan

7 QZSS orbits viewed from the equatorial plane at eastern hemisphere,with fixed camera view
92. QZSS 7SV Constellation Design•

The highest priority is toprovide good geometry(HDOP).
–•HDOP for 7 healthy SV with 10 degree EL mask

Japan and surrounding area
should have good HDOP, lessthan 2.6 on 95 time percentile.

SBAS user requirements on
the number of GSO
satellites is satisfied.
–More than 2 GSO SV for LPV
service to be provided by
Japanese Civil Aviation Bureau

4 IGSO + 2 GSO +1 QGSO*
constellation will be completedaround 2023*: QGSO Quasi-Geo Synchronous OrbitGeosynchronous orbit with small eccentricity and inclination1062. QZSS 7SV Constellation Design11

2. QZSS 7SV Constellation Design▌Visibility in Nagarkot, Nepal

122. QZSS 7SV Constellation Design▌Visibility in Nagarkot, Nepal

QZS-3 Elevation 34 deg
QZS-6 Elevation 57 deg

132. Future Expansion to 7SV constellation
Service Requirement for future 7SV constellation (2/2)
2. Augmentation services⚫ Both existing services, Sub meter Level Augmentation Service (SLAS) andCenti-meter Level Augmentation Service (CLAS) are to be provided indomestic area via current four SVs with same specifications.
⚫ MADOCA based PPP augmentation service will cover Asia Pacific region.

3. Messaging services⚫ Disaster and Crisis management Report (DCR) service, a kind of Early
Warning Service (EWS) will be expanded to Asia Pacific region.
◼ Common format is now being investigated with EC and other providers under ICG
correspondence group.

High accuracy augmentation (MADOCA-PPP) and Early Warning Service
into wider area in Asia Pacific region will be operational after 2023

14

2. QZSS 7SV Constellation Design-Practical PPP correction service in Asia Pacific region•

Experimental augmentation signal of MADOCA-PPP is now available for Asia-Pacific region.

•Operational service will start no later than 2024.

•For reduction of initial convergence period in PPP, QZS will provide the ionosphericcorrection data for some areas from 2024 as an experiment for future practical operation.

Ionospheric correction data will beprovided via L6D signal on QZS 5-7.

Error corrections for PPP will be provided
via L6E signal on QZS 1-7.

QZS#1-4
L6D:
CLAS

QZS#1-7
L6E:
PPP corr.

✔
✔
✔

Ionospheric delay✔
✔
✔
✔

Tropospheric delay✔

SV orbit error
Clock error
Code /pahse Bias

QZS#5-7
L6D:
Fast-PPP Ex✔

Fast PPP convergence time can be achieved withQZSS wide area ionosheric correction.

15

2. QZSS 7SV Constellation DesignLatest Updates -Early Warning Service (EWS)• QZSS L1S signal is sharing 250 bps data stream with SLAS and Disaster andCrisis Report service.
• DCR service is currently providing weather information generated by JMA forJapanese domestic users.
• Common EWS format is being investigated in collaboration with EC.
• QZSS ground segment will be upgraded to support EWS in 2024-2025 anddistribute EWS once every 4 seconds through QZS-1 to 4 satellites.
SignalService NameCenter freq.

Modulation

Bit Rate

L1S

Sub-meter Level Augmentation Service(SLAS)

1575.42MHz

BPSK

250bpsDC Report Service

Road Map for QZSS EWS expansion into Asia Pacific region
JFY

2018

Current operation
Upgraded plan
EWS expansion intoAsia Pacific region

2019

2020

2021

2022

2023

2024

2025～

DCR operation (Metrological warning delivery)*Nov. 1stService start

Manufacturing, Test
①Trial by Manual preparation★
★
Trial by EU ★
Trial★
in AU Trial in AU Trialin PHin Thailand②Trial by semi manual
operation(ftp connection)③Real timeoperation(VPN connection)16

2. QZSS 7SV Constellation Design
Latest Updates -Early Warning Service (EWS)• QZSS L1S signal is sharing 250 bps data stream with SLAS and Disaster andCrisis Report service.
• DCR service is currently providing weather information generated by JMA for
Japanese domestic users.
• Common EWS format is being investigated in collaboration with EC.
• QZSS ground segment will be upgraded to support EWS in 2024-2025 anddistribute EWS once every 4 seconds through QZS-1 to 4 satellites.
SignalService Name

Center freq.

Level
Service operation;
ChallengesSub-meterto be solvedin Augmentation
advance of practical(SLAS)

L1S

1575.42MHz

Modulation

Bit Rate

BPSK

250bpsDC Report
ServiceDue to narrow bandwidthof satellite
transmission through QZSS L1S, effective way toshareit among
stakeholders
in the region,
someprioritization
scheme will be required.
Road
Mapfor QZSSEWS expansion
into
Asia
Pacific region
JFY2018

Current operation
Upgraded plan
EWS expansion into
Asia Pacific region

2019202020212022202320242025～

DCR operation (Metrological warning delivery)*Nov. 1stService start

Manufacturing, Test
①Trial by Manual preparation★
★
Trial by EU ★
Trial★
in AU Trial in AU Trialin PH
in Thailand②Trial by semi manual
operation(ftp connection)③Real timeoperation(VPN connection)

17

Available Receiver, chipset for QZSS use

MADOCA-PPP
available

CLAS available

SLAS, EWS available

Please check
QZSS.go.jp

Most of smart phone can track QZSS

18

Available Receiver, chipset for QZSS use

MADOCA-PPP
available

List of products that support the QZSS is shown;https://qzss.go.jp/en/usage/products/list.html
CLAS available

SLAS, EWS available

Please check
QZSS.go.jp

Most of smart phone can track QZSS19

3. Summary• QZSS is Japanese regional navigation satellite system to improve
not only GNSS availability but also accuracy and reliability– 4 satellite constellation: Three IGSO and one GEO satellites– Providing PNT, augmentation and messaging services• On Nov 1st 2018, Japanese Government officially launched QZSSservice.
– The service performance has satisfied with the specifications.
– Application demonstrations were conducted.

• Future expansion to 7 satellite constellation– Started procurement process for additional 3 satellites• An IGSO, a GSO and a QGSO satellite will be added to the existing constellation– Service requirements were established• Cover Asia Oceania region for PNT services• Extension of High accuracy augmentation (MADOCA-PPP) and Early Warning
Service into AP region is being operational services
20

Participants can learn how to utilize EWS and PPP positioning through pototype developmentwith their team members.
Check MGA web site https://www.multignssasia.com/

Thank you for your attention!

For more information, please visit our web site

https://qzss.go.jp/en/
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