Change search
ReferencesLink to record
Permanent link

Direct link
Superdirective Microphone Arrays for Real Time Traffic Measurements
Norwegian University of Science and Technology, Faculty of Information Technology, Mathematics and Electrical Engineering, Department of Electronics and Telecommunications.
2013 (English)MasteroppgaveStudent thesis
Abstract [en]

The measurement of sound power from a car has traditionally been done by taking the car to a test site and driving it past a microphone several times. The use of microphone arrays and beamforming can make the aperture able to single out one car and follow it, taking a measurement of it, while suppressing the sound from the traffic around it. This master thesis studies two algorithms that might be used in this kind of set up: The Delay and Sum (DAS), and the Sparsity Constrained - Deconvolution Approach for the Mapping of Acoustic Sources (SC-DAMAS). This thesis tries to answer the questions: Is SC-DAMAS a better beamforming algorithm than DAS? And are they viable for a real time implementation for the measurement of cars in traffic? The SC-DAMAS algorithm achieves a far better signal to noise ratio than the DAS. In simulations with background noise levels that are 4 times higher than the source signal, the SC-DAMAS still achieved a signal to noise ratio of 10 dB. SC-DAMAS also excels in low frequency resolution: Where DAS results in a 4 m wide resolution at 400 Hz (for a 2 m long array), the SC-DAMAS manages to pinpoint the source to within one measurement field segment at 200 Hz. DAS on the other hand uses far less resources computing the results from one simulation. The SC-DAMAS used 270 times as much time concluding the simulation compared to DAS. In light of this result it is questionable whether it is possible to implement the SC-DAMAS in a way that lets it measure the sound power levels from a car in real time.

Place, publisher, year, edition, pages
Institutt for elektronikk og telekommunikasjon , 2013. , 40 p.
URN: urn:nbn:no:ntnu:diva-22534Local ID: ntnudaim:8861OAI: diva2:649778
Available from: 2013-09-19 Created: 2013-09-19 Last updated: 2013-09-19Bibliographically approved

Open Access in DiVA

fulltext(1455 kB)523 downloads
File information
File name FULLTEXT01.pdfFile size 1455 kBChecksum SHA-512
Type fulltextMimetype application/pdf
cover(184 kB)14 downloads
File information
File name COVER01.pdfFile size 184 kBChecksum SHA-512
Type coverMimetype application/pdf
attachment(2 kB)23 downloads
File information
File name ATTACHMENT01.zipFile size 2 kBChecksum SHA-512
Type attachmentMimetype application/zip

By organisation
Department of Electronics and Telecommunications

Search outside of DiVA

GoogleGoogle Scholar
Total: 523 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 55 hits
ReferencesLink to record
Permanent link

Direct link