I have no idea if the following sites will help, but I found them while surfing last night ...
http://www.sensortech.ca/materials.html
http://eng.bu.edu/~robinc/berlin.html (hand held sonar)
http://www.piezo.com/index.html (good tutorial)
http://www.piezo.com/catalog.html#te
http://mechatron.me.wisc.edu/Courses/me601/sonar/sonar.html (interesting notes)
http://sonatech.com/page03.htm
http://cgi.pbs.org/wgbh/nova/lochness/sonar.html (basic graphic on how sonar works)
http://newport.pmel.noaa.gov/~lau/sidescan/sidescan.html
Patrick
http://www.sensortech.ca/materials.html
http://eng.bu.edu/~robinc/berlin.html (hand held sonar)
http://www.piezo.com/index.html (good tutorial)
http://www.piezo.com/catalog.html#te
http://mechatron.me.wisc.edu/Courses/me601/sonar/sonar.html (interesting notes)
http://sonatech.com/page03.htm
http://cgi.pbs.org/wgbh/nova/lochness/sonar.html (basic graphic on how sonar works)
http://newport.pmel.noaa.gov/~lau/sidescan/sidescan.html
Patrick