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Acoustical direction finding with time-modulated arrays

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journal contribution
posted on 06.01.2017, 12:01 authored by Ben Clark, James FlintJames Flint
Time-Modulated Linear Arrays (TMLAs) offer useful efficiency savings over conventional phased arrays when applied in parameter estimation applications. The present paper considers the application of TMLAs to acoustic systems and proposes an algorithm for efficiently deriving the arrival angle of a signal. The proposed technique is applied in the frequency domain, where the signal and harmonic content is captured. Using a weighted average method on harmonic amplitudes and their respective main beam angles, it is possible to determine an estimate for the signal’s direction of arrival. The method is demonstrated and evaluated using results from both numerical and practical implementations and performance data is provided. The use of Micro-Electromechanical Systems (MEMS) sensors allows time-modulation techniques to be applied at ultrasonic frequencies. Theoretical predictions for an array of five isotropic elements with half-wavelength spacing and 1000 data samples suggest an accuracy of ±1∘ within an angular range of approximately ±50∘ . In experiments of a 40 kHz five-element microphone array, a Direction of Arrival (DoA) estimation within ±2.5∘ of the target signal is readily achieved inside a ±45∘ range using a single switched input stage and a simple hardware setup.

Funding

The authors are grateful for the financial support of Loughborough University’s Mini-Centre for Doctoral Training (mCDT) in Digital Technologies.

History

School

  • Mechanical, Electrical and Manufacturing Engineering

Published in

Sensors

Volume

16

Issue

12

Pages

2107 - 2107

Citation

CLARK, B. and FLINT, J., 2016. Acoustical direction finding with time-modulated arrays. Sensors, 16 (12), DOI: 10.3390/s16122107.

Publisher

MDPI (© the authors)

Version

VoR (Version of Record)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/ by/4.0/

Publication date

2016

ISSN

1424-8220

Language

en