Robust detection of North Atlantic right whales using deep learning methods

This thesis begins by assessing the current state of marine mammal detection, specifically investigating currently used detection platforms and approaches of detection. The recent development of autonomous platforms provides a necessity for automated processing of hydrophone recordings and suitable...

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Bibliographic Details
Main Author: Vickers, William
Format: Thesis
Language:English
Published: 2021
Subjects:
Online Access:https://ueaeprints.uea.ac.uk/id/eprint/87558/
https://ueaeprints.uea.ac.uk/id/eprint/87558/1/2022VickersWPhD.pdf
Description
Summary:This thesis begins by assessing the current state of marine mammal detection, specifically investigating currently used detection platforms and approaches of detection. The recent development of autonomous platforms provides a necessity for automated processing of hydrophone recordings and suitable methods to detect marine mammals from their acoustic vocalisations. Although passive acoustic monitoring is not a novel topic, the detection of marine mammals from their vocalisations using machine learning is still in its infancy. Specifically, detection of the highly endangered North Atlantic right whale (Eubalaena glacialis) is investigated. A large variety of machine learning algorithms are developed and applied to the detection of North Atlantic right whale (NARW) vocalisations with a comparison of methods presented to discover which provides the highest detection accuracy. Convolutional neural networks are found to outperform other machine learning methods and provide the highest detection accuracy when given spectrograms of acoustic recordings for detection. Next, tests investigate the use of both audio and image based enhancements method for improving detection accuracy in noisy conditions. Log spectrogram features and log histogram equalisation features both achieve comparable detection accuracy when tested in clean (noise-free), and noisy conditions. Further work provides an investigation into deep learning denoising approaches, applying both denoising autoencoders and denoising convolutional neural networks to noisy NARW vocalisations. After initial parameter and architecture testing, a full evaluation of tests is presented to compare the denoising autoencoder and denoising convolutional neural network. Additional tests also provide a range of simulated real-world noise conditions with a variety of signal-to-noise ratios (SNRs) for evaluating denoising performance in multiple scenarios. Analysis of results found the denoising autoencoder (DAE) to outperform other methods and had increased accuracy in all ...