Tsunami Warning System
MIDN 1/C Carlin Song
ES402 Systems Engineering Design
19 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
Pressure range:
Experiment (0 – 1.3 psi)
Sensor (0 – 13 psi)
Sensor application curve
90
80
70
Sensor  MCP 601  Rabbit
20
V  12
 0.0049V / count
2 1
Vout=-10+0.0049N
Depth (cm)
60
50
40
30
20
10
0
-10
200
300
400
500
600
700
800
Sensor Voltage (mV)
900
1000
1100
1200
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)
collected data
1.28
1.26
Averaged single waveform
1.28
1.26
1.22
1.24
Pressure (psi)
Pressure (psi)
1.24
1.2
1.18
0
10000
5000
15000
1.22
1.2
Time (ms)
1.18
0
500
1000
1500
2000 2500 3000
Time (ms)
3500
4000
4500
5000
Concept of Data Analysis (T = 5s)
Pressure readings (4th Order Curve Fit)
1.28
1.26
1.26
1.24
1.24
Pressure (psi)
Pressure (psi)
Averaged single waveform
1.28
1.22
1.22
1.2
1.2
1.18
1.18
1.16
0
500
1000
1500
2000 2500 3000
Time (ms)
3500
4000
4500
5000
1.16
74
76
78
Pressure = Pstatic + Pdynamic
80
Depth (cm)
82
84
86
Concept of Data Analysis (T = 5s)
Dynamic Pressure Readings(4th Order Curve Fit)

0.24
0.23
Dynamic Pressure (psi)
0.22
0.21
0.2
0.19
0.18

0.17
0.16
0.15
74
76
78
80
Depth (cm)
82
84
86
Subtract static
pressure from
readings using
application curve
data
Significant range
of dynamic
pressure
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