The underwater and airborne acoustic environment forms a critical part of many marine mammals lif... more The underwater and airborne acoustic environment forms a critical part of many marine mammals life cycles. Assessment and development of understanding of these acoustic soundscapes is often vital in understanding many marine life and human operation interactions as well as species to species interactions in the natural acoustic environments. Traditional passive acoustic methodologies used for underwater sound and noise measurements include static hydrophones, autonomous loggers, boat-based deployments, towed arrays, drifter systems etc. Most of these systems however also rely on expensive and sometimes hazardous deployments and retrieval methods. The rapid growth in Unmanned Ariel Vehicles (UAV) technologies in recent years has lead to investigation of these platforms to act as enhanced aerial visual platforms for observing marine mammal behaviour, abundance estimation etc. These systems are however often limited by battery life to relatively short in flight deployments. However these platforms can also offer the opportunity for rapid deployment of smart hydrophone systems over a relatively large spatial areas to include acoustic behaviours and sound scape analysis by flying to a site landing on the water and then deploying underwater sensors. Whilst on the waters surface relative power consumption is significantly lower than in-flight allowing significantly longer deployments. Smart systems will then return to some base point with minimal human interaction. A prototype multi-rotor system has been developed and tested in an open water site, capable of flying to site, landing on the water, deploying a wideband hydrophone for underwater noise assessment and then returning to base. Measurements include underwater noise self-noise analysis in-flight, landing, static and take-off and potential implications to marine wildlife. These developments and trials have demonstrated the overall feasibility of wide-scale rapid hydrophone deployment using UAVs for sound field and marine mammal behaviour analysis.
General rights Copyright and moral rights for the publications made accessible in the UHI Researc... more General rights Copyright and moral rights for the publications made accessible in the UHI Research Database are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights: 1) Users may download and print one copy of any publication from the UHI Research Database for the purpose of private study or research. 2) You may not further distribute the material or use it for any profit-making activity or commercial gain Marine Scotland is the directorate of the Scottish Government responsible for the integrated management of Scotland's seas. Marine Scotland Science (formerly Fisheries Research Services) provides expert scientific and technical advice on marine and fisheries issues. Scottish Marine and Freshwater Science is a series of reports that publishes results of research and monitoring carried out by Marine Scotland Science. It also publishes the results of marine and freshwater scientific work that has been carried out for Marine Scotland under external commission. These reports are not subject to formal peer-review. This report presents the results of marine and freshwater scientific work carried out for Marine Scotland under external commission.
Journal of the Acoustical Society of America, May 1, 2017
Traditional operations such as oil and gas exploration and production have long undergone sound f... more Traditional operations such as oil and gas exploration and production have long undergone sound field and environmental impact assessments of underwater acoustic noise. More recently emerging industries such as renewables (wind, wave, and tidal energy production) have also required scrutiny in terms of underwater noise sound fields. To make these assessments, sound fields are typically measured using hydrophones deployed from boats, drifting systems or moored acoustic data loggers. These measurements are often complex and expensive requiring complicated equipment deployments, boat operations and personnel in often-dangerous or hazardous environments. Unmanned Ariel Vehicles (UAV) or drone based technologies offer the opportunity for rapid deployment of smart hydrophone systems arrays over a large spatial area with significantly lower operator and boat interaction improving deployment flexibility, cost and minimising safety concerns for boat based deployments. Results presented are from tests of a prototype multi-rotor system in an open water site, capable of flying to site, landing on the water, deploying a wideband hydrophone for underwater noise assessment and then returning to base. These developments and trials have demonstrated the overall feasibility of wide-scale rapid hydrophone deployment using UAV based sensors and its potential application to underwater sound field assessment across a variety of industries.
Journal of the Acoustical Society of America, May 1, 2017
Tidal-stream turbines are a promising source of renewable electricity worldwide. These technologi... more Tidal-stream turbines are a promising source of renewable electricity worldwide. These technologies are sufficiently new that only single test devices have been deployed with arrays imminent. Being new, their interactions with marine organisms are poorly understood and the risk of large marine vertebrates colliding with their moving blades is a consenting and ecological concern. Operational noise is also considered a disturbance threat but under what circumstances is poorly defined. Further, the threats of collision and turbine noise may be inversely correlated with animals needing to hear turbines to avoid them. Consequently, there have been proposals to add extra-noise by fitting turbines with acoustic deterrents to warn or scare animals away. In this talk we examine the acoustic interactions between marine mammals and tidal turbines. The interactions are complex and depend on turbine source levels, ambient sound, propagation in moving water, sensory abilities, swim speeds and diving behaviour. In addition, the occurrence of turbines in arrays adds further complexity as responses to one turbine will impact collision risk with another. We then consider the options for and implications of adding additional warning sounds but such quick fixes might have unintended consequences that either increase collision risk or lead to undesirable avoidance.
Journal of the Acoustical Society of America, Oct 1, 2019
The growth of interest in the development of harnessing tidal energy has also led to the requirem... more The growth of interest in the development of harnessing tidal energy has also led to the requirement of assessment of underwaters sound fields in these environments. The radiated acoustic signatures of underwater systems in these environments is of significant interest. The measurements of the sound field in tidal flow areas however offer a number of major challenges. In a high flow environment, a static hydrophone would often suffer from significant flow noise. This parasitic noise is not real in the environment but a result of water column particle interaction with the hydrophone surface and has the capability of severely limiting the systems dynamic range for assessment of the true acoustic environment. Drifting system, moving at the speed of the water flow minimise this by reducing fluid particle to sensor interactions however are constrained by both temporal and spatial variations during the drifting limiting the ability to continuously monitor a system. Flow shield technology (sonar domes) have however been used extensively of the reverse problem of high-quality sound reception from a moving platform essentially suffering from the same problem. Work is presented on the use flow shield concept for a proto-type seabed mounted static recorder deployed in a high flow environment.
Marine mammals use vocalisations for a number of purposes: in locating food and underwater obstac... more Marine mammals use vocalisations for a number of purposes: in locating food and underwater obstacles, and to maintain contact with members of their family group. These sounds are loud in comparison with the ambient background, but are subject to masking due to underwater noise sources such as tidal turbines. We developed a model of animal movement which implements simple behavioural rules to allow group cohesion. We discuss some general features of group behaviour, and approaches to validation of the model using empirical data. Including external sources of noise can lead to loss of contact between group members. However, animals can take various measures to deal with these effects, such as more frequent vocalisation or "panic" swimming in response to sounds.
Acoustics can provide important information to assess underwater resources, noise and wildlife in... more Acoustics can provide important information to assess underwater resources, noise and wildlife interactions on marine energy sites. The European Marine Energy Centre (EMEC) has collaborated on a number of projects to develop acoustic technology, methods and quality control of monitoring techniques used for such assessments. This paper outlines previous and current activities at EMEC in this area, with a focus upon beneficial advances through knowledge exchange with Loughborough University and other knowledge partners.
This good practice guide was prepared by Stephen Robinson of the National Physical Laboratory wit... more This good practice guide was prepared by Stephen Robinson of the National Physical Laboratory with the assistance of Dr Paul Lepper (Loughborough University) and Dr Richard Hazelwood (R&V Hazelwood Associates). The work to develop new guidance has built upon the expertise already gained by researchers in a number of countries who have been actively engaged in discussions on this topic for some time. It is these informal discussions that have led to the initiation of standardisation work within ISO.
1. ABSTRACT The use of envelope detection methods to reduce the bandwidth of an echolocation clic... more 1. ABSTRACT The use of envelope detection methods to reduce the bandwidth of an echolocation click into the audio-band is not a new concept. However, the increasing popularity of portable digital recorders with excellent signal to noise performance needs such signal processing if ultrasonic transient data needs to be captured. Similarly, this approach allows high frequency information to be recorded onto video recorder sound tracks providing the advantage of synchronised sound with images for behavioural studies. This paper describes the development of a new generation of ECD with improved performance and includes cetacean echolocation data recorded using this equipment in two independent studies.
Conventional underwater based acoustic deployment platforms, such as boats, drifting systems or m... more Conventional underwater based acoustic deployment platforms, such as boats, drifting systems or moored long term acoustic data loggers are often expensive, complex and are usually deployed in dangerous environments. A novel alternative involving the use of a waterproof Unmanned Aerial System (UAS) for the deployment of underwater acoustic sensors is presented. The system has the capability of overcoming the limitations of current deployment methods, while also being able to self-deploy and self-retrieve, and will improve deployment and redeployment times.
Presented at the Small Unmanned Aerial Systems for Environmental Research conference http://www.w... more Presented at the Small Unmanned Aerial Systems for Environmental Research conference http://www.worcester.ac.uk/discover/uav-conference.html.
A framework to predict, validate and review the acoustic footprints of operating tidal turbines [... more A framework to predict, validate and review the acoustic footprints of operating tidal turbines [abstract]
Environmental dependence of underwater sound propagation resulting from percussive pile driving [... more Environmental dependence of underwater sound propagation resulting from percussive pile driving [abstract]
Although acoustic systems are increasingly being used for environmental and noise surveys of mari... more Although acoustic systems are increasingly being used for environmental and noise surveys of marine energy devices, there are currently no standard protocols for the on-site full bandwidth calibration of these systems. Reports often include little or no information on the methods of calibration used before, during or after surveys. Without proper calibration, the sound levels may be far from accurate, leading to skewed reporting and inaccurate conclusions. Hydrophone calibrations from internationally recognised standardisation centres, such as NPL, allow providers to reference their systems to international standards. Marine renewable energy devices, however, are often deployed in remote areas and it is not always practical or cost-effective to send every acoustic system to be independently tested before every deployment. On-site referencing of multiple units to a single standardised system can help improve calibration traceability. Although this may at first appear relatively simple, the production of an accurate, full-spectrum calibration, particularly in real-world test sites, is surprisingly difficult.
Pile-driving of marine foundations can radiate substantial levels of low-frequency impulsive nois... more Pile-driving of marine foundations can radiate substantial levels of low-frequency impulsive noise into the water column, which given the right acoustic propagation environment conditions can propagate over large distances. Concern over the potential for impact on marine fauna often results in a regulatory requirement to measure the radiated noise level over distances which may extend tens of kilometres. Furthermore, if the transmission loss is to be established or validated it would be necessary to measure as a function of range at a number of positions. Because of the variation in hammer energy during the pile-driving activity, particularly if a soft-start is employed, it is also desirable to perform the measurement independent of distance for the duration of the pile-driving operation. A number of others factors will also influence the noise radiated into the water column, including the water depth (exposing a different amount of the surface area of the pile), the seabed properties, the penetration depth into the seabed by the pile, the pile dimensions, and the hammer energy. Importantly, some of these factors may change during pile-driving of an individual pile, for example tidal variation and sediment penetration, and this means that the acoustic output is likely to change during the driving of a specific pile. A method for the measurement of this underwater noise, that is generally in relatively shallow water, which considers both the spatial and temporal variation of the sound field is described. The method includes a combination of fixed autonomous recorders and vessel based hydrophone deployments. The paper describes the activities within the International Organization for Standardization (ISO), Technical Committee 43, Sub-Committee 3, Working Group 3 to produce an international standards document to define the appropriate measurement methodology, which should be followed when measuring underwater noise radiated from marine pile-driving.
The underwater and airborne acoustic environment forms a critical part of many marine mammals lif... more The underwater and airborne acoustic environment forms a critical part of many marine mammals life cycles. Assessment and development of understanding of these acoustic soundscapes is often vital in understanding many marine life and human operation interactions as well as species to species interactions in the natural acoustic environments. Traditional passive acoustic methodologies used for underwater sound and noise measurements include static hydrophones, autonomous loggers, boat-based deployments, towed arrays, drifter systems etc. Most of these systems however also rely on expensive and sometimes hazardous deployments and retrieval methods. The rapid growth in Unmanned Ariel Vehicles (UAV) technologies in recent years has lead to investigation of these platforms to act as enhanced aerial visual platforms for observing marine mammal behaviour, abundance estimation etc. These systems are however often limited by battery life to relatively short in flight deployments. However these platforms can also offer the opportunity for rapid deployment of smart hydrophone systems over a relatively large spatial areas to include acoustic behaviours and sound scape analysis by flying to a site landing on the water and then deploying underwater sensors. Whilst on the waters surface relative power consumption is significantly lower than in-flight allowing significantly longer deployments. Smart systems will then return to some base point with minimal human interaction. A prototype multi-rotor system has been developed and tested in an open water site, capable of flying to site, landing on the water, deploying a wideband hydrophone for underwater noise assessment and then returning to base. Measurements include underwater noise self-noise analysis in-flight, landing, static and take-off and potential implications to marine wildlife. These developments and trials have demonstrated the overall feasibility of wide-scale rapid hydrophone deployment using UAVs for sound field and marine mammal behaviour analysis.
General rights Copyright and moral rights for the publications made accessible in the UHI Researc... more General rights Copyright and moral rights for the publications made accessible in the UHI Research Database are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights: 1) Users may download and print one copy of any publication from the UHI Research Database for the purpose of private study or research. 2) You may not further distribute the material or use it for any profit-making activity or commercial gain Marine Scotland is the directorate of the Scottish Government responsible for the integrated management of Scotland's seas. Marine Scotland Science (formerly Fisheries Research Services) provides expert scientific and technical advice on marine and fisheries issues. Scottish Marine and Freshwater Science is a series of reports that publishes results of research and monitoring carried out by Marine Scotland Science. It also publishes the results of marine and freshwater scientific work that has been carried out for Marine Scotland under external commission. These reports are not subject to formal peer-review. This report presents the results of marine and freshwater scientific work carried out for Marine Scotland under external commission.
Journal of the Acoustical Society of America, May 1, 2017
Traditional operations such as oil and gas exploration and production have long undergone sound f... more Traditional operations such as oil and gas exploration and production have long undergone sound field and environmental impact assessments of underwater acoustic noise. More recently emerging industries such as renewables (wind, wave, and tidal energy production) have also required scrutiny in terms of underwater noise sound fields. To make these assessments, sound fields are typically measured using hydrophones deployed from boats, drifting systems or moored acoustic data loggers. These measurements are often complex and expensive requiring complicated equipment deployments, boat operations and personnel in often-dangerous or hazardous environments. Unmanned Ariel Vehicles (UAV) or drone based technologies offer the opportunity for rapid deployment of smart hydrophone systems arrays over a large spatial area with significantly lower operator and boat interaction improving deployment flexibility, cost and minimising safety concerns for boat based deployments. Results presented are from tests of a prototype multi-rotor system in an open water site, capable of flying to site, landing on the water, deploying a wideband hydrophone for underwater noise assessment and then returning to base. These developments and trials have demonstrated the overall feasibility of wide-scale rapid hydrophone deployment using UAV based sensors and its potential application to underwater sound field assessment across a variety of industries.
Journal of the Acoustical Society of America, May 1, 2017
Tidal-stream turbines are a promising source of renewable electricity worldwide. These technologi... more Tidal-stream turbines are a promising source of renewable electricity worldwide. These technologies are sufficiently new that only single test devices have been deployed with arrays imminent. Being new, their interactions with marine organisms are poorly understood and the risk of large marine vertebrates colliding with their moving blades is a consenting and ecological concern. Operational noise is also considered a disturbance threat but under what circumstances is poorly defined. Further, the threats of collision and turbine noise may be inversely correlated with animals needing to hear turbines to avoid them. Consequently, there have been proposals to add extra-noise by fitting turbines with acoustic deterrents to warn or scare animals away. In this talk we examine the acoustic interactions between marine mammals and tidal turbines. The interactions are complex and depend on turbine source levels, ambient sound, propagation in moving water, sensory abilities, swim speeds and diving behaviour. In addition, the occurrence of turbines in arrays adds further complexity as responses to one turbine will impact collision risk with another. We then consider the options for and implications of adding additional warning sounds but such quick fixes might have unintended consequences that either increase collision risk or lead to undesirable avoidance.
Journal of the Acoustical Society of America, Oct 1, 2019
The growth of interest in the development of harnessing tidal energy has also led to the requirem... more The growth of interest in the development of harnessing tidal energy has also led to the requirement of assessment of underwaters sound fields in these environments. The radiated acoustic signatures of underwater systems in these environments is of significant interest. The measurements of the sound field in tidal flow areas however offer a number of major challenges. In a high flow environment, a static hydrophone would often suffer from significant flow noise. This parasitic noise is not real in the environment but a result of water column particle interaction with the hydrophone surface and has the capability of severely limiting the systems dynamic range for assessment of the true acoustic environment. Drifting system, moving at the speed of the water flow minimise this by reducing fluid particle to sensor interactions however are constrained by both temporal and spatial variations during the drifting limiting the ability to continuously monitor a system. Flow shield technology (sonar domes) have however been used extensively of the reverse problem of high-quality sound reception from a moving platform essentially suffering from the same problem. Work is presented on the use flow shield concept for a proto-type seabed mounted static recorder deployed in a high flow environment.
Marine mammals use vocalisations for a number of purposes: in locating food and underwater obstac... more Marine mammals use vocalisations for a number of purposes: in locating food and underwater obstacles, and to maintain contact with members of their family group. These sounds are loud in comparison with the ambient background, but are subject to masking due to underwater noise sources such as tidal turbines. We developed a model of animal movement which implements simple behavioural rules to allow group cohesion. We discuss some general features of group behaviour, and approaches to validation of the model using empirical data. Including external sources of noise can lead to loss of contact between group members. However, animals can take various measures to deal with these effects, such as more frequent vocalisation or "panic" swimming in response to sounds.
Acoustics can provide important information to assess underwater resources, noise and wildlife in... more Acoustics can provide important information to assess underwater resources, noise and wildlife interactions on marine energy sites. The European Marine Energy Centre (EMEC) has collaborated on a number of projects to develop acoustic technology, methods and quality control of monitoring techniques used for such assessments. This paper outlines previous and current activities at EMEC in this area, with a focus upon beneficial advances through knowledge exchange with Loughborough University and other knowledge partners.
This good practice guide was prepared by Stephen Robinson of the National Physical Laboratory wit... more This good practice guide was prepared by Stephen Robinson of the National Physical Laboratory with the assistance of Dr Paul Lepper (Loughborough University) and Dr Richard Hazelwood (R&V Hazelwood Associates). The work to develop new guidance has built upon the expertise already gained by researchers in a number of countries who have been actively engaged in discussions on this topic for some time. It is these informal discussions that have led to the initiation of standardisation work within ISO.
1. ABSTRACT The use of envelope detection methods to reduce the bandwidth of an echolocation clic... more 1. ABSTRACT The use of envelope detection methods to reduce the bandwidth of an echolocation click into the audio-band is not a new concept. However, the increasing popularity of portable digital recorders with excellent signal to noise performance needs such signal processing if ultrasonic transient data needs to be captured. Similarly, this approach allows high frequency information to be recorded onto video recorder sound tracks providing the advantage of synchronised sound with images for behavioural studies. This paper describes the development of a new generation of ECD with improved performance and includes cetacean echolocation data recorded using this equipment in two independent studies.
Conventional underwater based acoustic deployment platforms, such as boats, drifting systems or m... more Conventional underwater based acoustic deployment platforms, such as boats, drifting systems or moored long term acoustic data loggers are often expensive, complex and are usually deployed in dangerous environments. A novel alternative involving the use of a waterproof Unmanned Aerial System (UAS) for the deployment of underwater acoustic sensors is presented. The system has the capability of overcoming the limitations of current deployment methods, while also being able to self-deploy and self-retrieve, and will improve deployment and redeployment times.
Presented at the Small Unmanned Aerial Systems for Environmental Research conference http://www.w... more Presented at the Small Unmanned Aerial Systems for Environmental Research conference http://www.worcester.ac.uk/discover/uav-conference.html.
A framework to predict, validate and review the acoustic footprints of operating tidal turbines [... more A framework to predict, validate and review the acoustic footprints of operating tidal turbines [abstract]
Environmental dependence of underwater sound propagation resulting from percussive pile driving [... more Environmental dependence of underwater sound propagation resulting from percussive pile driving [abstract]
Although acoustic systems are increasingly being used for environmental and noise surveys of mari... more Although acoustic systems are increasingly being used for environmental and noise surveys of marine energy devices, there are currently no standard protocols for the on-site full bandwidth calibration of these systems. Reports often include little or no information on the methods of calibration used before, during or after surveys. Without proper calibration, the sound levels may be far from accurate, leading to skewed reporting and inaccurate conclusions. Hydrophone calibrations from internationally recognised standardisation centres, such as NPL, allow providers to reference their systems to international standards. Marine renewable energy devices, however, are often deployed in remote areas and it is not always practical or cost-effective to send every acoustic system to be independently tested before every deployment. On-site referencing of multiple units to a single standardised system can help improve calibration traceability. Although this may at first appear relatively simple, the production of an accurate, full-spectrum calibration, particularly in real-world test sites, is surprisingly difficult.
Pile-driving of marine foundations can radiate substantial levels of low-frequency impulsive nois... more Pile-driving of marine foundations can radiate substantial levels of low-frequency impulsive noise into the water column, which given the right acoustic propagation environment conditions can propagate over large distances. Concern over the potential for impact on marine fauna often results in a regulatory requirement to measure the radiated noise level over distances which may extend tens of kilometres. Furthermore, if the transmission loss is to be established or validated it would be necessary to measure as a function of range at a number of positions. Because of the variation in hammer energy during the pile-driving activity, particularly if a soft-start is employed, it is also desirable to perform the measurement independent of distance for the duration of the pile-driving operation. A number of others factors will also influence the noise radiated into the water column, including the water depth (exposing a different amount of the surface area of the pile), the seabed properties, the penetration depth into the seabed by the pile, the pile dimensions, and the hammer energy. Importantly, some of these factors may change during pile-driving of an individual pile, for example tidal variation and sediment penetration, and this means that the acoustic output is likely to change during the driving of a specific pile. A method for the measurement of this underwater noise, that is generally in relatively shallow water, which considers both the spatial and temporal variation of the sound field is described. The method includes a combination of fixed autonomous recorders and vessel based hydrophone deployments. The paper describes the activities within the International Organization for Standardization (ISO), Technical Committee 43, Sub-Committee 3, Working Group 3 to produce an international standards document to define the appropriate measurement methodology, which should be followed when measuring underwater noise radiated from marine pile-driving.
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