Acoustic Source Localisation
- June 14, 2017
- Posted by: marlenedubois
- Category: CPR Training
Performance of certain direction of arrival (DOA) estimation algorithms using a uniform linear array of scalar sensors has been analyzed along with reported. Velocity hydrophones, which measure one Cartesian component of the three-dimensional particle velocity vector of the incident wave field, were first reported in underwater acoustics literature in 1956. although the importance of simultaneously measuring both pressure along with particle velocity was recognized almost three decades later when Mann etc. published a classic paper addressing the fundamentals of energy transfer in acoustic field.
The relevance of This particular brand-new approach was further elucidated by G. L. D’Spain. The technology of vector hydrophones or acoustic vector sensors (AVS), consisting of three orthogonally oriented velocity hydrophones plus a pressure hydrophone, all spatially collocated, for simultaneous measurement of pressure along with particle velocities is actually of relatively recent vintage. the item has attracted considerable interest, especially within the signal processing community, after Nehorai along with Paldi presented the AVS measurement type along that has a method for localising acoustic sources using an array of such sensors. Hochwald along with Nehorai later addressed the important issue of identifiability with vector sensors, namely, the bound on the number of sources identifiable in a class of array processing designs with multiple parameters along with signals per source. Hawkes along with Nehorai have quantified the impact of sensor locations on the performance (Cramer Rao Bound) of an AVS array.
In a separate paper they have defined some performance measures such as mean square angular error (MSAE) along with mean square range error (MSRE) along with derived asymptotic lower bounds on these quantities in terms of the CRB. The same authors have also discussed the correlations between the measurements within an AVS as well as between two spatially separated acoustic vector sensors. They have also analysed the effect of a reflecting boundary along with presented a fast method for localising a wideband source using a distributed AVS array.
A host of beamforming techniques using vector sensors have also appeared from the literature. Wong along with Zoltowski introduced ESPRIT-based closed form source localisation for arbitrarily spaced 3D arrays of vector hydrophones. They have also proposed aperture extension using a uniform rectangular array of vector hydrophones spaced much farther than half a wavelength to achieve enhanced array resolution along with direction-finding precision. Narrowband Beamforming along with Capon direction estimation methods with an AVS array have been discussed by Hawkes along with Nehorai. Root-MUSIC based azimuth-elevation DOA estimation technique using uniformly spaced velocity hydrophones has been developed by Wong along with Zoltowski. They have also proposed a blind MUSIC-based source localisation algorithm using arbitrary 3D array of vector hydrophones. The same authors have also presented a near-field/far-field azimuth-elevation angle estimation algorithm using an individual vector hydrophone.