The Problem

1
ACOUSTIC SOURCE LOCALIZATION USING ACOUSTIC
VECTOR SENSORS
Joshua York , Patricio S. La Rosa, Ed Richter,
and Arye Nehorai Department of Electrical and
Systems Engineering
Azimuth and elevation estimation
Abstract
Experimental Setup and GUI
Measurement model
Acoustic source
Acoustic source
Illustration of the main components of our
experimental setup
An acoustic vector sensor (AVS) measures all the
three components of the acoustic particle
velocity and the pressure at a single point in
space. Through real experiments, the study
evaluated the advantages of AVS for source
localizing problems, compared with standard
pressure sensor arrays. For this aim, we built a
linear array of four AVS and design a graphical
user interface for processing the measurements
and estimating the source location in 3D. This
research considered the source identifiability
using a single AVS, as well as 3D location
estimation using a linear array of AVS.
Array of AVS
Capon Spectra
AVS
Far acoustic field
Signal conditioner
Overview
Euler equation
DAQ

• Goal
• Estimate the position of an acoustic source using
  spatial and temporal measurements of pressure and
  particle acoustic field
• Approach
• Physical modeling of the propagation of an
  acoustic waveform through the air.
• Statistical analysis of pressure and particle
  velocity measurements taken by an array of
  acoustic vector sensors.
• Applications
• Assisted navigation, defense, teleconference,
  vibration analysis
• Background

pressure at position r and time t
Figure Power distribution as a function of
azimuth and elevation The red arrow indicates the
maximum spectral value.
particle velocity at position r and time t
direction of particle velocity
Numerical Example Source identifiability
speed of sound,
Ambient pressure
SNR1 SNR2 SNR
A) Single AVS
Single AVS and source model
pressure-sensor-measurement noise
particle-velocity-measurement noise
SNR -3 dB
SNR 12 dB
SNR 6 dB
Multiple AVS and single source model
B) Two AVS
Steering vector
Estimation algorithm
References

• A. Nehorai and E. Paldi, Acoustic vector
  sensor array processing," Proc. 26th Asilomar
  Conf. Signals, Syst. Comput., pp. 192-198,
  Pacific Grove, CA, Oct. 1992.
• A. Nehorai and E. Paldi, "Acoustic vector-sensor
  array processing," IEEE Trans. on Signal
  Processing, Vol. SP-42, pp. 2481-2491, Sept.
  1994.
• M. Hawkes and A. Nehorai, "Acoustic
  vector-sensor beamforming and capon direction
  estimation," IEEE Trans. on Signal Processing,
  Vol. SP-46, pp. 2291-2304, Sept. 1998.

FigurePhotograph of a three dimensional sound
intensity probe consisting of one pressure sensor
and three particle velocity sensors mounted
together (Source Microflown Technologies, B.V.)
Capon Spectra
sample-correlation matrix for N samples