With the popularity of ultrasound therapy in clinics, characterization of the acoustic field is important not only to the tolerability and efficiency of ablation, but also for treatment planning. A quantitative method was introduced to assess the intensity distribution of a focused ultrasound beam using a hydrophone and an infrared camera with no prior knowledge of the acoustic and thermal para...

The present study originated in the lack of research into achieving underwater total internal reflection (TIR) via the acousto-optic effect. The uniqueness of this technique exists in the fact that it is based on a high sound pressure level which induces a localised change in refractive index of seawater sufficient to achieve total internal reflection within the communication channel. Different...

The ANTARES group at the University of Erlangen is working towards the integration of a set of acoustic sensors into the ANTARES Neutrino Telescope 1. With this setup, tests of acoustic particle detection methods and background studies shall be performed. The ANTARES Neutrino Telescope, which is currently being constructed in the Mediterranean Sea, will be equipped with the infrastructure to ac...

. Vibro-acoustography (VA) is an acoustic image modality based on the response of tissue under excitation of two ultrasound beams with different-frequencies. The aim of this paper is to provide a quantitative analysis with experimental measurements of the difference-frequency (DF) pressure generated in VA. This analysis considered the radiation force , the induced acoustic emission, and nonline...

This paper proposes an innovative concept that responds to the requirements of acoustic REA as the integration between a network of sophisticated Acoustic-Oceanographic Buoys (AOB) and online ocean properties inversion algorithms. A prototype of the system, including one sonobuoy and a preliminary version of the inversion code, was tested at sea during the MREA’03 sea trial. The AOB is a light ...

This letter describes a ray-based blind deconvolution technique for ocean sound channels that produces broadband estimates of the source-to-array impulse response and the original source waveform from array-measured signals corrupted by (unknown) multipath propagation. The technique merely requires elementary knowledge of array geometry and sound speed at the array location. It is based on iden...

This paper explores acoustic field simulation of 128 elements cylindrical phased array. The simulations were performed in a homogenous medium water at several frequencies from 2.25 MHz to 7.5 MHz. Beam width versus the focal distance with a different number of active elements for chosen focal distance is simulated. To determine focusing efficiency of the cylindrical array the beam width of the ...

Non-invasive range and bearing estimation of buried objects, in the underwater acoustic environment, has received considerable attention (Granara et al., 1998). Many studies have been recently developed. Some of them use acoustic scattering to localize objects by analyzing acoustic resonance in the time-frequency domain, but these processes are usually limited to simple shaped objects (Nicq & B...

A method for estimating the sound absorption coefficient of a material under a synthesized Diffuse Acoustic Field was recently proposed, as an alternative to classical sound absorption measurements in reverberant rooms. Using sound field reproduction approaches and a synthetic array of acoustic monopoles facing the material, estimation of the sound absorption coefficient under a reproduced Diff...

This paper presents an overview of the experiment INTIMATE96, carried out in June 1996 on the continental shelf off the coast of Portugal and discusses the effects of internal tides on the acoustic propagation. A towed broadband acoustic source and a 4-hydrophone vertical array were used. Acoustic data were collected for 5 days, including legs where the source ship was moving and legs with the ...