PLEASE PRE-REGISTER FOR THIS EVENT BY GOING TO:
A number of two-pulse sonar techniques can be employed to separate linear and nonlinear scatterers. Twin Inverted Pulse Sonar (TWIPS) and Biased Pulse Summation Sonar (BiaPSS) are processes that exploit nonlinear bubble dynamics to perform such a classification, with clutter reduction. Consequently, these techniques can be used to enhance target detection in bubbly waters. TWIPS and BiaPSS rely upon bubbles being driven to large nonlinear pulsations, but this is dependent upon availability of a high-amplitude source. Previous studies could only access a narrow-band source and therefore used a low frequency so that, over the rarefaction cycle, most ocean bubbles would expand sufficiently (the size range of near-surface ocean bubbles under waves and wakes being large). However, recent access to a broadband high-power source has allowed exploitation of bubble resonances.
This talk presents results of investigations using broadband linear sine sweeps, of which one is based upon the simulation of an Atlantic Bottlenose Dolphin (Tursiops truncatus) echolocation click from Capus et al. (2006). Insonifying a cloud of bubbles with a wide band of frequencies excites as many of those sizes at, or close to, their resonance. As such, the contrast between linear and nonlinear scatter is enhanced, improving target detection capability.
Topics and speakers for the evening meetings are generally identified and organised by the London Branch Committee, but we always welcome new ideas and suggestions for future presentations. If you have any ideas or suggestions, or may even like to give a presentation yourself, please contact the London Branch Committee (Roslyn Andrews: Roslyn.Andrews@aecom.com )
This event is free to IOA members and the general public, however, numbers are strictly limited and we request that you pre-register for this event by going to the registration page at:
If you register and are no longer able to attend this event, please cancel your ticket or contact Vicky.Stewart@atkinsglobal.com so that your place can be offered to someone else.
The closest underground stations to the venue are Chancery Lane (Central line) and Holborn (Central & Piccadilly line).
For more details of IOA regional branch activities please refer to the IOA website: www.ioa.org.uk
70 Chancery Lane
London,
WC2A-1AF
United Kingdom