Acoustic Fossil Imaging

byMatt Kaiser & John Lewis

Advised by: Dr. James H. Irwin & Mr. José Sánchez

Outline

Matt Kaiser John Lewis

-Project Summary-Functional Description-References-Parts List-Schedule

-System Level Block Diagram -Sub-System Level Block Diagrams-Specification Sheet-User Interface

Project Summary

Goal: Image Fossils Buried in Rock

Major Components: Ultrasonic Sensor, Data Acquisition, and PC

Signal Processing in MATLAB

Data Acquisition with Tektronix TDS3012B e*scope

System Block Diagram

Data Acquisition

Overall Block Diagram

Sensor Block Diagram

Acoustic Sensor

Description: A device that sends a burst of 16 50[kHz] acoustical pulses

Acoustic Foam

Description: The acoustical foam narrows the dispersion angle of the sensor to provide more accurate results

Oscilloscope Block Diagram

Oscilloscope

Description: The oscilloscope provides a means to view the data graphically

Format Output

Description: This allows the graphical data to be put into a form that can be imported to a PC with MATLAB

Signal Processing

PC with MATLAB

Description: The signal processing will allow the user to see the object in three dimensions, and will give other useful data about the object (e.g. length, width, and height)

Software Flow ChartImport Data

This converts the data into a useable form for MATLAB manipulation

Correlate Data

This allows multiple echoes contained in each other to be determined

Dimension Determination

Using time delays the dimensions of an object can be determined

3-D Plot

This allows the user to view a specific object in 3-D

User Interface

Move Sensor by Hand

Acquire Data with Oscilloscope

Run MATLAB M-File

Specifications

Parameter Min Typ Max Units

Power Supply Voltage 4.5 5 6.8 V

Input Frequency - 10 - Hz

Input Voltage 0 - 4 V

Transmit Frequency - 49.4 - kHz

Transmit Pulses - 16 - -

Transmit Sensitivity 110 - - dB

Receive Frequency -42 - - dB

Operating Temperature 0 - 40 °C

Operating Distances 6 - 35 ft

Vertical Directivity Pattern 0 - 60 °

Parts List

Ultrasonic Transducer

Tektronix Oscilloscope

HP Single Power Supply

Krohn-Hite Function Generator

PC

“Chips”

ReferencesAcoustic imaging: The reconstruction of underwater objects, IEEE Visualization, 1991, p. 94-101, ISBN: 0-8186-2245-8

Brunner, Eberhard, Ultrasound System Considerations and Their Impact on Front-End Components, Analog Devices, 2002

Case study: Visualization of 3-D ultrasonic data, IEEE Visualization, 1994, p. 369-373, ISBN: 1070-2385

Schedule

Date Planned Work

January 27 Implement New Sensor

February 3 Work on Better Test Platform and Sensor Hardware

February 10 Acquire Data and Process

February 17 Work on More Complex Calculation Routines

February 24 Attempt to Image Objects Buried with Other Objects

March 2 Continue Complex Imaging

March 9 Implement More Sensors if Necessary

March 16 Spring Break

March 23 Testing

March 30 Testing

April 6 Final Software and Hardware Implementation & Testing

April 13 Make Adjustments to Improve System

April 20 Prepare for Expo

April 27 Prepare Final Presentation

May 4 Finishing Touches on Documentation

Questions?

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