Ciencia y Tecnologías Físicas >
Instituto de Acústica (IA) >
(IA) Artículos >
Open Access item Waveform Shaping of Sonar Transducers for Improving the Vertical Resolution in Sub-bottom Sediments Profiling
Ranz Guerra, Carlos
Anthony, David K.
|Keywords:||Sub-bottom profiling, High resolution, Inverse filtering, Waveform shaping, Sonar transducers|
|Citation:||Marine Geophysical Researches 26:87-95 (2005)|
|Abstract:||Vertical resolution is of fundamental importance in sonar exploration and is directly related to the duration of the acoustic pulse generated by the transducer. The shorter the radiated pulse, the higher the vertical resolution. Many sub-bottom profiling sonar systems use piezoelectric transducers because they are reversible and well understood. Piezoelectric projectors are normally resonant transducers, which are intrinsically narrowband. A piezoelectric transducer is usually driven by a tone-burst. However, it is possible to use Fourier techniques to find a pre-compensated electrical driving function so that the transducer radiates a prescribed wider band acoustic waveform. This technique can be applied to synthesize zero-phase cosine-magnitude, Gaussian, and bionic pulses, with a conventional sandwich transducer. Zero-phase cosine-magnitude waveforms provide minimum length pulses (and therefore maximum resolution) within a prescribed frequency band.The aim of this paper is to illustrate the synthesis of wideband acoustic pulses using an underwater piezoelectric projector. The conventional acoustic waveform radiated when a Tonpiltz transducer is transiently excited using a “click” and allows its frequency response function to be measured. This function is used to design the electrical signal which then drives the transducer so that it radiates the shortest pulse compatible with its mechanical response. The significant resolution enhancement of the waveform shaping process is illustrated by its application to a sediment wedge model.|
|Description:||Final full-text version of the paper available at SpringerLink: http://dx.doi.org/10.1007/s11001-005-3709-6.|
|Appears in Collections:||(IA) Artículos|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.