Tsunami Monitoring System for

early warning by using GNSS

Hiroaki Tateshita

Japan Aerospace Exploration Agency

(JAXA)

Contents

• Background

• Experiment 2011 – 2012

• Next Step: Experiment 2012 – 2013

• Summary

Background• The Earthquakes and Tsunamis have caused

extensive and severe damages in Japan

• The systems to provide accurate and necessary

information for tsunami evacuation more quickly and

surely have been researched and developped

AP/Press Association image

4

Tsunami Monitoring System (current)• Existing System uses RTK-GPS, therefore the accuracy is

getting decrease if the distance from coast is more than 20 km

– condition due to the length of base line of RTK and communication line

– Coastal base station necessary

– inadequate time from ditecting Tsunami to warning and evacuation

GPS

Buoy

Analysis

Center

NAV

Signal

NAV Signal

Base

Station

Communication

Line

Real time data transmission

20kmLeading time = 10 min

Courtesy of Hitachi Zosen Corp.

5

Tsunami Monitoring System (Next Gen)

GPS

Buoy

Tsunami

Monitoring Center

NAV Signal

QZSS

NAV Signal

+Augmentation

Signal for PPP

Precise Point Positioning (PPP) by via QZSS LEX signal can provide precise position (target accuracy: less than ±10cm）

•No coastal equipment necessary -> the buoy can be put more than 100 km far from costal area

•More time for early warning and evacuation after Tsunami detection

•Decreasing data amount by sending only positioning results

Courtesy of Hitachi Zosen Coｒｐ.

More than 100km

Data collection via Com. Sat

Experiment 2011-2012

Hitachi Zosen Corp., Tokyo Univ.,

Kochi national College of Technology

and JAXA

Application to Tsunami buoy system

Data analysis

in postprocess

Compare LEX-PPP

with kinematic

method

Base station#1

Base station#2

QZS-1 MICHIBIKI

Off Muroto capeTsunami monitoring

buoy

GPSGPS

GPS

GPS

Hitachi Zosen Corp.

47km

Kochi prefecture,

Japan

• Install GNSS receiver on tension mooring buoy

• Compare LEX-PPP with Kinematic (BL=13, 47km)

• 1st gen orbit/clock estimation system

GPS QZSS

Tsukuba Space Center

・・・

Master Control Station(MCS)

LEX

LEX signal

PPP Application

Demonstration

LEX signal

Tracking &Control Station

(Okinawa)

demonstrations of various applications

of precise positioning

(ex) Tsunami Monitoring

Precise Agriculture

・・・

QZSS Monitoring Station(nine stations for QZSS)

Precise orbit/clock estimation

Current Configuration for Precicse Point

Positioning (PPP) Technical Experiment

8

Experiment Results (Availability)

Date(UTC) Kinematic*1

(BL13km)

Kinematic*1

(BL47km)

LEX-PPP*2 Wind Speed*3

[m/s]

Sep10. 2011

(calm)92.7% 72.3% 100%

Ave. 4

Max 6.1

Sep16. 2011

(procellous)97.0% 77.8% 100%

Ave. 11.2

Max 15.6

1day statistics (15sec interval)

Date/Time

(UTC)

Kinematic*1

(BL13km)

Kinematic*1

(BL47km)

LEX-PPP*2 Wind Speed*3

[m/s]

Sep10. 2011

10:00-11:0082.1% 76.2% 100% Ave. 2.4

Sep16. 2011

10:00-11:00100% 88.1% 100% Ave. 11.3

1hour statistics (1sec interval)

*1 Count fix solution *2 Count PPP solution *3 At Muroto cape

Experiment Results (Vertical Accuracy)

Time[MM:SS]

He

igh

t[m

]

He

igh

t[m

]

Time[MM:SS]

Sep.10 (calm) 10:00-11:00(UTC) Sep.16 (procellous) 10:00-11:00(UTC)

He

igh

t[m

]

He

igh

t[m

]

60sec 60sec

1 hour 1 hour

Time[HH:MM] Time[HH:MM]

Experiment Results (Horizontal Accuracy)

Time[MM:SS]Time[MM:SS]

Sep.10 (calm) 10:00-11:00(UTC)

Ea

st-W

est

axi

s[m

]

No

rth

-So

uth

axi

s[m

]

60sec 60sec

Ea

st-W

est

axi

s[m

]

No

rth

-So

uth

axi

s[m

]

1 hour 1 hour

Time[HH:MM] Time[HH:MM]

NEXT STEP:

experiment 2012-2013

JAMSTEC - TOHOKU UNIV. - JAXA

Sea floor Sea floor Sea floor Sea floor

pressure sensorpressure sensorpressure sensorpressure sensor

Seafloor

station

QZSS

LEX signal

Communication

satellite

Tsunami

warning

m-Triton

Buoy

Crustal

movement

Background

Requirements

• Real-time tsunami detection of

more than 100km coastal areas.

• Real-time positioning of the buoy

for seafloor crustal movement

measurement.

Objective

• Study the applicability and

effectiveness of QZSS in tsunami

disaster.

GPS

Tsunami

detection

QZSS/GNSS QZSS/GNSS QZSS/GNSS QZSS/GNSS

positioning for positioning for positioning for positioning for

Tsunami detectionTsunami detectionTsunami detectionTsunami detection

Antenna

Solar Panel

GNSS Reciever,

Logger, Modem for

Satellite

Communication

Batteries, controler

for base station

ocean bottom

pressure sensor

Crustal deformation

Observation

m-TRITON buoy

JAMSTEC - Tohoku UNIV. – JAXA

Collaboration• Development of New buoy observation

system for tsunami and crustal deformation under strong sea current– JAMSTEC

• Buoy for Strong Sea Currents environment

• Tsunami Monitoring by using an ocean bottom pressure sensor

– Tohoku Univ.• Crustal deformation Observation

– JAXA• PPP(Precise Point Positioning）

• Satellite Communication

We put the new buoy system on the ocean. The

test and data analysis will be conducted soon.

JAMSTEC/Tohoku Univ. JAXA

・QZS-1③③③③Precise Point Positioning

・Communication Satellite

（ETS-VIII ...）

・m-Triton Buoy

・Tsunami Detection System①①①①Ocien Bottom pressure sensor

②②②②Crustal deformation Observation

海底水圧計

ﾜｲﾔｰ下の

ﾄﾗﾝｽﾃﾞｭｰｻ

m-triton

Buoy

水圧ﾃﾞｰﾀ

衛星通信

地殻変動検知用

海底局

精密軌道・

クロック情

報を生成

リアルタイム

PPP測位

Next-gen high accuracy positioning

platform

(MGM-net etc.)

GPS GLONASS Galileo QZSS : “MICHIBIKI”

Tsukuba space center

・・・

RTCM

MADOCA

LEX

message

Master Control

Station(MCS)

LEX message

LEX message

NTRIP Caster

(External server)

Multi-GNSS Application

Demonstration

LEX signal

Tracking &Control

Station

(Okinawa)

Various demonstration experiments

example：

・detection and warning of Tsunami

・precise agriculture

・estimation of precipitable water

・・・

InternetPPP users

Current target accuracy is less than 10cm.

MADOCA: Muliti-gnss Advanced Demonstration tool for Orbit-and-Clock Analysis

Including precise orbit and clock of Multi-GNSS

orbit & clock

estimation

LEX message

generation

RTCM SSR

extension

LEX

message

navigation signal

Data interface

Summary

• The systems to provide accurate and necessary information for tsunami evacuation more quickly and surely have been researched and developped

• As a result of experiment 2011 – 2012, PPP can provide the similar level of accuracy and availability with RTK

• As Next Step, New buoy observation system for tsunami and crustal deformation under strong sea current was developped. The test and data analysis will be conducted soon.