ASIAEx 2001

The "Shark of Science" hydrophone array sled.

Source Signals We Used

• We had 2 frequency modulated (sweeper) moored sources. One transmitted a 300Hz signal and the other transmitted a 500Hz signal. (Computer generated 500Hz sample)
• We also had two 400Hz phase encoded moored sources. (Computer generated 400Hz sample)
• We also had one 224Hz phase encoded moored source. (Computer generated 224Hz sample)
• The actual sound of our sources being played 5,000 times louder than the signal at the receiver (you wouldn't hear it otherwise).

Actual sounds from the ocean floor (all amplified 300 times louder)

• The sound of a South China Sea fishing vessel.
• The sound of common light bulb implosion that we used for hydrophone localization, heard from over 1 kilometer away.
• The sound of a hydrophone being dragged over the sandy bottom by strong internal waves.
• The sound of a shackle hitting our top float after an internal wave went by.
• The sound of a local fisherman, fishing with explosives.

A look at the frequency spectrum and a description of these sounds

• All Sources
• fishing vessel
• light bulb implosion
• shackle
• fishing with explosives
• being dragged