QZSS Early Warning System (EWS)

Dinesh ManandharCenter for Spatial Information Science

The University of Tokyo
Contact Information: dinesh@csis.u-tokyo.ac.jp

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 1

Background Information

QZSS EWS message is broadcasted using QZSS L1S signal structure that uses signal structure
similar to SBAS signal. EWS also requires knowledge about Navigation Message structure. So,some background information on SBAS signals, GPS and SBAS navigation messages are provided.

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 2

GNSS
Global Navigation Satellite System (GNSS) is the standard generic term for allnavigation satellites systems like GPS, GLONASS, GALILEO, BeiDou, QZSS, NAVIC.
• Global Constellation• Regional Constellation• GPS, USA• GLONASS, Russia• Galileo, Europe• BeiDou (COMPASS) / BDS, China• QZSS, Japan• NAVIC (IRNSS), India

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 3

Systems Related with NavigationNavigation Satellite Systems
GPS, GLONASS, Galileo, BeiDou, QZSS, NavIC

Augmentation Systems
SBAS or GBAS
Satellite Based Augmentation Systems(SBAS)PVT Computation Engine(Position, Velocity and Time)
Ground Based Augmentation Systems(GBAS)PVT Solutions withEnhanced Accuracy and Reliability

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 4

Satellite Based Augmentation System (SBAS)• Satellite Based Augmentation System (SBAS) are used to augment GNSS Data
• Provide Higher Accuracy and Integrity• Correction data for satellite orbit errors, satellite clock errors, atmospheric correction
data and satellite health status are broadcasted from satellites• SBAS Service Providers••••••••••

WAAS, USA (131,133,135,138)
MSAS, Japan (129,137)
EGNOS, Europe (120,121,123,124,126,136)
BDSBAS, China (130,143,144)
GAGAN, India (127,128,132)
SDCM, Russia (125,140,141)
KASS, Korea (134), Also Navigation System
AUS-NZ, Australia (122)
NSAS, Nigeria, (147)
ASAL, Algeria (148)

PRN code numbers are given in the bracket

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 5

GPS L1C/A Signal Structure• Carrier Signal• It defines the frequency of the signal• For example:• GPS L1 is 1575.42MHz, L2 is 1227.60MHz and L5 is 1176.45MHz• PRN Code• Used to identify satellite ID in CDMA
• Requires to modulate the data
• Should have good auto-correlation and cross-correlation properties• Navigation Data

• Includes satellite orbit related data (ephemeris data)• Includes satellite clock related information (clock errors etc)
Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 6

GPS Signals
BandL1L2L5Frequency,
MHz1575.42

1227.60

1176.45

ModulationType

Data /SymbolRate,bps/sps

Notes

1.023

BPSK50Legacy Signal

101.023

BOC(1,1)

50 / 100

From 2014

CPilot101.023TMBOC

No Data

BOC(1,1) & BOC(6,1)P(Y)

7 days

10.23

BPSK

CM

20

0.5115SignalType

CodeLengthmsec

Chip Rate,
MHz

C/A

1CDataCL

1500

0.5115

P(Y)

7days

10.23

I

1Q

1

10.23

Restricted

25 / 50BPSK

No DataModulated by TDM of(L2CM xor Data) andL2CL

50 / 100

Provides Higher
Accuracy

BPSK
BPSK

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

No DataSlide : 7

QZSS Signals and PRN ID
PRN
193
183
193
194
184
196
194
199

SVN

Satellite

Launch Date(UTC)

Orbit

J001

QZS-1

2010/9/11

QZO

J002

QZS-2

2017/6/1

QZO

L1C/A, L1C, L2C, L5
L1S
L6
L1C/A, L1C, L2C, L5
L1S
L5S
L6
L1C/A, L1C, L2C, L5

189
197
137
199
195
185
200
195

Positioning Signals

J003

QZS-3

2017/8/19

GEOJ004

QZS-4

2017/10/9

QZO

Source: https://qzss.go.jp/technical/satellites/index.html
2022/01/16 10:32 PM

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

L1S
L5S
L1Sb
L6Sr/Sf
L1C/A, L1C, L2C, L5
L1S
L5S
L6Slide : 8

QZSS Signals and PRN ID
QZS-1R was launched on 2021/10/26. 1R represent replacement for SVN 1.
PRN
196
186
186
196

SVN

J005

Source: https://qzss.go.jp/technical/satellites/index.html
2022/01/16 10:32 PM

Satellite NameQZS-1R

Launch Date(UTC)2021/10/26

Orbit

Positioning Signals

QZO

L1C/A, L1C, L2C, L5
L1S
L5S
L6Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 9

QZSS EWS

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 10

Slide from QZSS Presentation by S. Kogure, UTokyo/ICG GNSS Training, 11 – 14 January 2022
Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 11

This slide is taken from presentation slides of S. Kogure, Introduction to Michibiki and EWS, presented on 13th July 2021
2022/01/16 10:32 PMDinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 12EWS System Architecture
QZSS

EWS Message
Decoding
GNSS(Pos. Vel.,Time)

2Coding
Display EWS
Message

Coding Interface
NB-IoT
WiFi / BLE

SPRESENSE Device

QZSS Control Office
Japan

3

NB-IoT
WiFi/BT

Send by e-mail1

4

EWS Test Message

5

6Flashing light

Wailing siren

7Teams generate sample EWS message
See documents: EWS_Format.pdf
EWS_Message_Example.pdf

Minimum Requirement as MVP (Minimum Viable Product) for PoC level Prototype:
Item (1) : Generate sample test EWS message
Item (2) : Read EWS message from Spresense device and display in a PC

Alarm, Evacuation
Guidance

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Showing message
on signage display

Slide : 13

SBAS / EWS Message Format
EWS Message: Early Warning System Message
DC Report: Disaster Crisis Report, QZSS uses the term DC Report instead of EWS.

Preamble
8 bitsData Rate
Symbol Rate

Message
Type6 bits

EWS Message Data
212 bits

CRC
24 bits: 250bps: 500sps (1/2 rate FEC)

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 14

Earthquake Early Warning Message Format

https://qzss.go.jp/en/technical/ps-is-qzss/is_qzss_dcr_008_agree.html
https://qzss.go.jp/en/technical/ps-is-qzss/ps-is-qzss.html
Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 15

Earthquake Early Warning Message Format

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 16

DC Report message output from a receiver• DC (Disaster Crisis) Report message output format• QZSS uses the term “DC” instead of EWS.
• All output data shall be interpreted as ASCII characters• The beginning of the sentence is message header "$QZQSM“• Satellite ID is 6 LSB of the 8 bit which represented PRN of the L1S• PRN 183 0xB7 10110111b  110111b (Take 6LSBs)  5510
• PRN 183 corresponds to 55• 250bit DC Report Message are added two binary data "00" at end of amessage to make 252 bit data
• A carriage return code (CR) and a linefeed code (LF) are added at the end of asentence

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 17

GNSS Navigation Data BitsDinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 18

U-blox Screen Shot

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 19

QZSS Navigation Message Data BitsSV
QZSS 1QZSS 1QZSS 3QZSS 3QZSS 7
QZSS 7MSG
L1S0
L1C/A 0
L1S 0
L1C/A 0
L1S 0
L1C/A 0DATA (* denotes invalid words)
43
9AADF545 D18002C3 F25880CB 115A81F9 503FCA08 214106A8 64500013 7E7063B1322C0AA24 2E8E83F8 3FD7D58F 2D517A6C 3FF28752 AA27838C 060F7023 0D26BAE0 3FF4A787 2E78F7AB
439AADF545 D18002C3 F25880CB 115A81F9 503FCA08 214106A8 64500013 7E7063B1322C0AA81 AE8E8327 00263E35 BA997E7F 3FBF0777 03133174 3061EFC3 3F4A8413 3FFA2DF0 2E7DE57F
439AADF545 D18002C3 F25880CB 115A81F9 503FCA08 214106A8 64500013 7E7063B1322C0AA81 AE8E8327 01D759E0 25981C5D 8069002C 036272D5 809D87FF 2ECDBB5E 80021FAB 2E40007CDinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 20

DC Report message output from a receiver

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 21

SPRESENSE Main Board

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 22

Sample NMEA Output Data from Spresense Device$QZQSM,56,53ADF6105400050FB4A1F7D4403A880C51022A2711450028A2D00010E28E564*05$QZDCM,Message Type,14$GPGGA,072433.00,3554.1824,N,13956.3583,E,2,09,1.2,54.3,M,39.3,M,,*52$GPGSV,3,1,09,03,09,310,38,12,05,050,37,16,07,235,36,22,11,288,,0*69$GPGSV,3,2,09,25,37,046,44,26,42,252,45,29,48,089,46,31,59,329,47,0*6B$GPGSV,3,3,09,32,63,180,51,,,,,,,,,,,,,0*55$GQGSV,2,1,05,56,86,275,48,01,45,189,44,02,86,275,47,03,22,167,40,0*6B$GQGSV,2,2,05,07,46,201,39,,,,,,,,,,,,,0*5D$GNRMC,072433.00,A,3554.1824,N,13956.3583,E,0.0,22.2,041221,,,D,V*05$GNVTG,22.2,T,,M,0.0,N,0.0,K,D*24$GPGGA,072434.00,3554.1824,N,13956.3583,E,2,09,1.2,54.3,M,39.3,M,,*55$GPGSV,3,1,09,03,09,310,38,12,05,050,37,16,07,235,36,22,11,288,,0*69$GPGSV,3,2,09,25,37,046,44,26,42,252,45,29,48,089,45,31,59,329,47,0*68$GPGSV,3,3,09,32,63,180,51,,,,,,,,,,,,,0*55$GQGSV,2,1,05,56,86,275,48,01,45,189,44,02,86,275,46,03,22,167,39,0*64$GQGSV,2,2,05,07,46,201,38,,,,,,,,,,,,,0*5C$GNRMC,072434.00,A,3554.1824,N,13956.3583,E,0.0,22.2,041221,,,D,V*02$GNVTG,22.2,T,,M,0.0,N,0.0,K,D*24
Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 23

Sample NMEA Output Data from Spresense Device$GPGGA,072436.00,3554.1824,N,13956.3583,E,2,09,1.2,54.3,M,39.3,M,,*57$GPGSV,3,1,09,03,09,310,38,12,05,050,36,16,07,235,37,22,11,288,,0*69$GPGSV,3,2,09,25,37,046,43,26,42,252,46,29,48,089,45,31,59,329,46,0*6D$GPGSV,3,3,09,32,63,180,51,,,,,,,,,,,,,0*55$GQGSV,2,1,05,56,86,275,48,01,45,189,44,02,86,275,46,03,22,167,41,0*6B$GQGSV,2,2,05,07,46,201,38,,,,,,,,,,,,,0*5C$GNRMC,072436.00,A,3554.1824,N,13956.3583,E,0.0,22.2,041221,,,D,V*00$GNVTG,22.2,T,,M,0.0,N,0.0,K,D*24$QZQSM,56,9AADF6104F000283F2507F8A106961F92C406588AD40FF28208000111573F9C*74$QZDCM,Message Type,14$GPGGA,072437.00,3554.1824,N,13956.3583,E,2,09,1.2,54.3,M,39.3,M,,*56

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 24

Demo:EWS Message from Spresense Device

If you want to access EWS message from Spresense device, please send request e-mail to me.

Dinesh Manandhar, CSIS, The University of Tokyo, dinesh@csis.u-tokyo.ac.jp

Slide : 25