Tsunami Warning System

MIDN 1/C Carlin SongES402 Systems Engineering Design19 February 2008

Tsunami Phenomenon

large-scale, short-duration vertical displacement of water column.

generated by subduction earthquakes

principal source regions are earthquake zones in the Pacific Ocean

Life of a Tsunami Wave

Generation

Amplification

Run-up

Wave Motion & Dynamic Pressure

wave motion creates dynamic pressure which is measurable up to the wave base (L/2)

Shallow water wave characteristics of tsunami wave allows detection of dynamic pressure in deep ocean

Sensor Selection and Calibration

200 300 400 500 600 700 800 900 1000 1100 1200-10

0

10

20

30

40

50

60

70

80

90

Dep

th (

cm)

Sensor Voltage (mV)

Sensor application curve

Pressure range: Experiment (0 – 1.3 psi)

Sensor (0 – 13 psi)

Sensor MCP 601 Rabbit

countVV /0049.012

2012

Vout=-10+0.0049N

Experimental Set-up

Buffer Op-Amp

ZigBee Network Set-up

Wireless Personal Area Network (WPAN) Meshing capability

Low cost Low power requirement

Secure networking

Concept of Data Analysis (T = 5s)

0 5000 10000 15000

1.18

1.2

1.22

1.24

1.26

1.28collected data

Time (ms)

Pre

ssur

e (p

si)

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000

1.18

1.2

1.22

1.24

1.26

1.28Averaged single waveform

Time (ms)

Pre

ssur

e (p

si)

Concept of Data Analysis (T = 5s)

Pressure = Pstatic + Pdynamic

0 500 1000 1500 2000 2500 3000 3500 4000 4500 50001.16

1.18

1.2

1.22

1.24

1.26

1.28Averaged single waveform

Time (ms)

Pre

ssur

e (p

si)

74 76 78 80 82 84 861.16

1.18

1.2

1.22

1.24

1.26

1.28Pressure readings (4th Order Curve Fit)

Depth (cm)

Pre

ssur

e (p

si)

Concept of Data Analysis (T = 5s)

Subtract static pressure from readings using application curve data

Significant range of dynamic pressure

74 76 78 80 82 84 86

0.15

0.16

0.17

0.18

0.19

0.2

0.21

0.22

0.23

0.24Dynamic Pressure Readings(4th Order Curve Fit)

Depth (cm)

Dyn

amic

Pre

ssur

e (p

si)

Decision Parameter

Existence of dynamic pressure Amplitude range for dynamic

pressure Existence of low freq, high

amplitude signal Abnormal spike in voltage readings

Communications Infrastructure

3 in 4 tsunami alarms are false Evacuation for false cases causes

complacency Reliable and timely communications

system Current efforts

Online Data Transmission

Dynamic C program Digitize buffered output voltage from

sensor suite using Rabbit ADC Records time corresponding to voltage

data collection Arranges voltage and time data as an

ASCII string Output ASCII string to Serial Port B Zigbee attached to Serial Port B for

wireless transmission

Data Collection and Analysis

Data collection criteria Maximize time resolution in order to best detail

wave MATLAB code

Open ASCII string received at remote laptop via wireless transmission

Change digital voltage data to analog values Perform data analysis to find dynamic pressure of

passing wave Determine if recorded dynamic pressure is above

threshold pressure

Tsunami Warning System