Investigation of Sound Speed Errors in Adaptive Beamforming

Iben Kraglund Holfort, Fredrik Gran, Jørgen Arendt Jensen

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

389 Downloads (Pure)


Previous studies have shown that adaptive beam-formers provide a significant increase of resolution and contrast, when the propagation speed is known precisely. This paper demonstrates the influence of sound speed errors on two adaptive beamformers; the minimum variance (MV) beamformer and the amplitude and phase (APES) beamformer. Simulations of a single point target are carried out in Field II, and a percentage error is applied on the speed of sound. As the error increases, MV and APES provide amplitude drops of 17 dB and 3 dB on the signal strength. Two approaches to overcome this amplitude drop is proposed; diagonal loading (DL) and forward-backward (FB) averaging of the covariance matrix. The investigations show that DL provides a slightly decreased resolution and amplitude compared to FB. It is noted that APES provides more robust estimates than MV at the mere expense of a slight decrease of resolution. From the investigations, it is concluded the performance of the adaptive beamformers are not outperformed by the conventional delay-and-sum beamformer.
Original languageEnglish
Title of host publicationProceedings of the IEEE International Ultrasonics Symposium
Publication date2008
ISBN (Print)978-1-4244-2428-3
Publication statusPublished - 2008
Event2008 IEEE International Ultrasonics Symposium - Beijing, China
Duration: 2 Nov 20085 Nov 2008


Conference2008 IEEE International Ultrasonics Symposium
Internet address

Bibliographical note

Copyright: 2008 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE

Fingerprint Dive into the research topics of 'Investigation of Sound Speed Errors in Adaptive Beamforming'. Together they form a unique fingerprint.

Cite this