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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.
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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 MCP 601 Rabbit 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) Pressure = Pstatic + Pdynamic
Concept of Data Analysis (T = 5s) • 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