Acoustics for underwater neutrino telescopes

En esta tesis se tratan diferentes aspectos de la acústica presente en un telescopio submarino de neutrinos, principalmente en dos vertientes: en el sistema de posicionamiento acústico utilizado para la monitorización de las posiciones de los módulos ópticos presentes a lo largo del detector, así como en sistemas para detección acústica de neutrinos, técnica que actualmente está en fase de estudio. Todos los estudios realizados están enmarcados dentro de dos colaboraciones europeas para el diseño, construcción y operación de telescopios submarinos de neutrinos: Antares (en fase de operación) y KM3NET (en fase de diseño). Objetivos. Los objetivos de este trabajo pueden resumirse en los siguientes aspectos: - Estudios y análisis del sistema de posicionamiento acústico de Antares. Desarrollo del software para la para la automatización del procesado de los datos de dicho sistema e incorporación de los resultados en la base de datos del experimento. Análisis de los datos proporcionados por dicho sistema con el fin de validar su correcto funcionamiento. - Diseño y desarrollo del sistema de posicionamiento acústico para KM3NeT, telescopio unas 20 veces más grande que Antares. - Estudios para la evaluación de la generación acústica paramétrica para el desarrollo de un calibrador compacto capaz de generar señales tipo neutrino útiles en sistemas de detección acústica. Elementos de la metodología a destacar. Cabe destacar aquí que el trabajo se ha desarrollado en el marco de dos colaboraciones internacionales: ANTARES y KM3NeT, financiados con fondos europeos y nacionales. Por su contexto y el carácter de las actividades realizadas ha sido necesaria la formación en distintos campos: telescopios de neutrinos y astropartículas, pero también en otras áreas como la acústica submarina. Además, se ha desarrollado diversas capacidades y destrezas en diversos ámbitos: en instrumentación, en aplicaciones informáticas, en análisis de datos, etc. Más concretamente, se ha trabajado en aplicaciones informáticas para los desarrollos y análisis en ANTARES.Bou Cabo, M. (2011). Acoustics for underwater neutrino telescopes [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/10989Palanci

Development of a trigger for acoustic neutrino candidates in KM3NeT

The KM3NeT Collaboration is constructing two large neutrino detectors in the Mediterranean Sea: ARCA, located near Sicily and aiming at neutrino astronomy, and ORCA located near Toulon and designed for the study of intrinsic neutrino properties. The two detectors together will have hundreds of Detection Units with Digital Optical Modules kept vertically by buoyancy forming a large 3D optical array for detecting the Cherenkov light produced after the neutrino interactions. To properly reconstruct the direction of the incoming neutrino, the position of the DOMs, which are not static due to the sea currents, must be monitored. For this purpose, the detector is equipped with an Acoustic Positioning System, which is composed of fixed acoustic emitters on the sea bottom, a hydrophone in each DU base, and a piezoceramic sensor in each DOM, as acoustic receivers. This network of acoustic sensors can be used not only for positioning, but also for acoustic monitoring studies such as bioacoustics, ship noise monitoring, environmental noise control, and acoustic neutrinos detection. This work explores the possibility of creating a trigger for saving the data for ultra-high-energy neutrino candidates detected acoustically by the hydrophones. The acoustic signal caused by the neutrino interaction in a fluid is a short-time duration Bipolar Pulse extremely directive and with a Fourier transform extending over a wide range of frequencies. A study of signal detection, has been done by simulating BP produced by the interaction of a UHE neutrino at 1 km from the detector at zero-degree incidence added to the experimental real acoustic data. Finally, a trigger proposal has been developed in order to record candidates of BPs and it has been tested. The number of candidates per second, precision, and recall have been monitored according to the cuts applied and parameters calculated by the algorithm.Comment: 9th International Workshop on Acoustic and Radio EeV Neutrino Detection Activities - ARENA202

Design and Application of a Passive Acoustic Monitoring System in the Spanish Implementation of the Marine Strategy Framework Directive

[EN] A passive acoustic monitoring (PAM) device named SAMARUC has been developed to acquire underwater sounds following the specifications of the Monitoring Guidance for Underwater Noise in European Seas: Monitoring Guidance Specifications. Based on a Texas Instruments processor, an ultra-low power ADC was programmed to work at a sampling rate of 192 kHz and adhoc electronics were designed allowing the processor¿s two microSD buses to be used, thereby increasing the storage capacity. Many other software and hardware enhancements were implemented, such as the new low latency file system, the construction of NITUFF anodized aluminium housing and ringed buoys. With the resulting application, data obtained by the SAMARUC at El Gorguel (Cartagena, Spain) in 2018 were compared to a theoretical underwater noise map created using AIS data. This was done following the Descriptor D11.2 by means of the ambient noise level indicators at two one-third-octave frequency bands (63 Hz and 125 Hz), mainly related to marine traffic and noise pollution. The conjunction between the acquisition of underwater acoustic data and the development of a numerical propagation model was found to be highly recommendable to estimate the ambient continuous noise level when validating the acquired data as well as when correcting the prediction provided by the model.Lara, G.; Bou-Cabo, M.; Esteban, JA.; Espinosa Roselló, V.; Miralles Ricós, R. (2019). Design and Application of a Passive Acoustic Monitoring System in the Spanish Implementation of the Marine Strategy Framework Directive. MDPI. 1-7. https://doi.org/10.3390/ecsa-6-06568S1

Underwater Acoustic Positioning System for the Monitoring of KM3NeT Optical Modules

[EN] KM3NeT, the underwater neutrino telescope in the Mediterranean Sea, is a detector under construction. KM3NeT uses Digital Optical Modules (DOMs) to detect neutrinos by detecting the Cherenkov light of relativistic particles produced in the interaction. To reconstruct the neutrino event and the coming direction, it is necessary to monitor the position of each DOM, which is not fixed since it is mounted in flexible string lines, held close to vertical by buoys but sensitive to sea currents. A piezo-ceramic transducer is installed inside of each DOM. Using some emitters anchored in the sea floor it is possible to calculate the position of the DOMs by triangulation of distances obtained from the determination of the time of flight of the acoustic wave. In this work, the acoustic model used for the simulation of the system is described and the results presented.[ES] KM3NeT, el detector submarino que se encuentra en construcción en el Mar Mediterráneo, usa Módulos Digitales Ópticos (DOMs) para localizar neutrinos, a través de la detección de la luz de Cherenkov producida por partículas relativistas durante la interacción con el agua. Para reconstruir el camino seguido por el neutrino, es necesario saber la posición de cada DOM, el cuál no se encuentra fijo ya que está sujeto a unos cables anclados que se mantienen en vertical gracias a una boya en el final de la línea, lo cual la hace sensible al movimiento de las corrientes marinas. Cada DOM contiene instalada una cerámica piezoeléctrica, como receptor acústico, y usando unos emisores anclados en el fondo del mar se puede estimar la posición de cada DOM triangulando las distancias entre ellos, las cuales se saben por el tiempo de vuelo de la señal acústica. En este trabajo, se presenta una simulación del sistema y se describe el modelo acústico usado.Ardid Ramírez, M.; Bou Cabo, M.; D. Tortosa, D.; Martínez Mora, JA.; Poirè, C. (2019). Underwater Acoustic Positioning System for the Monitoring of KM3NeT Optical Modules. Revista de Acústica. 50(3-4):24-33. http://hdl.handle.net/10251/160009S2433503-

Underwater noise studies in the Gulf of Lions region. Anthropogenic contributions to underwater noise due to maritime traffic and offshore windfarm operation

En el marco del proyecto MSPMED se ha llevado a cabo un caso de estudio transfronterizo entre España y Francia en relación al estado de los ecosistemas, el desarrollo de la eólica marina y el ruido submarino,. Este deliverable analiza cómo podría ser el impacto del ruido submarino producido por el tráfico marítimo y la eólica marina en el componente pelágico

New Insights into the Design and Application of a Passive Acoustic Monitoring System for the Assessment of the Good Environmental Status in Spanish Marine Waters

[EN] Passive acoustic monitoring systems allow for non-invasive monitoring of underwater species and anthropogenic noise. One of these systems has been developed keeping in mind the need to create a user-friendly tool to obtain the ambient noise indicators, while at the same time providing a powerful tool for marine scientists and biologists to progress in studying the effect of human activities on species and ecosystems. The device is based on a low-power processor with ad-hoc electronics, ensuring that the system has efficient energy management, and that the storage capacity is large enough to allow deployments for long periods. An application is presented using data from an acoustic campaign done in 2018 at El Gorguel (Cartagena, Spain). The results show a good agreement between theoretical maps created using AIS data and the ambient noise level indicators measured in the frequency bands of 63 Hz and 125 Hz specified in the directive 11 of the EU Marine Strategy Framework Directive. Using a 2D representation, these ambient noise indicators have enabled repetitive events and daily variations in boat traffic to be identified. The ship noise registered can also be used to track ships by using the acoustic signatures of the engine propellers¿ noise.Lara Martínez, G.; Miralles Ricós, R.; Bou-Cabo, M.; Esteban, JA.; Espinosa Roselló, V. (2020). New Insights into the Design and Application of a Passive Acoustic Monitoring System for the Assessment of the Good Environmental Status in Spanish Marine Waters. Sensors. 20(18):1-12. https://doi.org/10.3390/s20185353S1122018Lara, G., Bou-Cabo, M., Esteban, J. A., Espinosa, V., & Miralles, R. (2019). Design and Application of a Passive Acoustic Monitoring System in the Spanish Implementation of the Marine Strategy Framework Directive. Proceedings of 6th International Electronic Conference on Sensors and Applications. doi:10.3390/ecsa-6-06568SAMARUC Webhttp://samaruc.webs.upv.esExplora (Patents and Software) UPV Webhttps://aplicat.upv.es/exploraupv/ficha-tecnologia/patente_software/15065?busqueda=R-16202-2012Beghi, M. G. (Ed.). (2013). Modeling and Measurement Methods for Acoustic Waves and for Acoustic Microdevices. doi:10.5772/2581Oceans Physics at Your Fingertipshttps://www.emodnet-physics.eu/Map/Gridded Bathymetric Datahttps://www.gebco.net/data_and_products/gridded_bathymetry_data/Mackenzie, K. V. (1981). Nine‐term equation for sound speed in the oceans. The Journal of the Acoustical Society of America, 70(3), 807-812. doi:10.1121/1.386920Ross, D., & Kuperman, W. A. (1989). Mechanics of Underwater Noise. The Journal of the Acoustical Society of America, 86(4), 1626-1626. doi:10.1121/1.398685Gervaise, C., Kinda, B. G., Bonnel, J., Stéphan, Y., & Vallez, S. (2012). Passive geoacoustic inversion with a single hydrophone using broadband ship noise. The Journal of the Acoustical Society of America, 131(3), 1999-2010. doi:10.1121/1.3672688Crocker, S. E., Nielsen, P. L., Miller, J. H., & Siderius, M. (2014). Geoacoustic inversion of ship radiated noise in shallow water using data from a single hydrophone. The Journal of the Acoustical Society of America, 136(5), EL362-EL368. doi:10.1121/1.4898739Li, H., Yang, K., Duan, R., & Lei, Z. (2017). Joint Estimation of Source Range and Depth Using a Bottom-Deployed Vertical Line Array in Deep Water. Sensors, 17(6), 1315. doi:10.3390/s17061315Tong, J., Hu, Y.-H., Bao, M., & Xie, W. (2013). Target tracking using acoustic signatures of light-weight aircraft propeller noise. 2013 IEEE China Summit and International Conference on Signal and Information Processing. doi:10.1109/chinasip.2013.6625333Lo, K. W., Perry, S. W., & Ferguson, B. G. (2002). Aircraft flight parameter estimation using acoustical Lloyd’s mirror effect. IEEE Transactions on Aerospace and Electronic Systems, 38(1), 137-151. doi:10.1109/7.993235Miralles, R., Lara, G., Gosalbez, J., Bosch, I., & León, A. (2019). Improved visualization of large temporal series for the evaluation of good environmental status. Applied Acoustics, 148, 55-61. doi:10.1016/j.apacoust.2018.12.00

Acoustic Transmitters for Underwater Neutrino Telescopes

In this paper acoustic transmitters that were developed for use in underwater neutrino telescopes are presented. Firstly, an acoustic transceiver has been developed as part of the acoustic positioning system of neutrino telescopes. These infrastructures are not completely rigid and require a positioning system in order to monitor the position of the optical sensors which move due to sea currents. To guarantee a reliable and versatile system, the transceiver has the requirements of reduced cost, low power consumption, high pressure withstanding (up to 500 bars), high intensity for emission, low intrinsic noise, arbitrary signals for emission and the capacity of acquiring and processing received signals. Secondly, a compact acoustic transmitter array has been developed for the calibration of acoustic neutrino detection systems. The array is able to mimic the signature of ultra-high-energy neutrino interaction in emission directivity and signal shape. The technique of parametric acoustic sources has been used to achieve the proposed aim. The developed compact array has practical features such as easy manageability and operation. The prototype designs and the results of different tests are described. The techniques applied for these two acoustic systems are so powerful and versatile that may be of interest in other marine applications using acoustic transmitters.Comment: 21 pages, 14 figures,1 tabl

A Risk-Based Model Using Communication Distance Reduction for the Assessment of Underwater Continuous Noise: An Application to the Bottlenose Dolphin (Tursiops truncatus) Inhabiting the Spanish North Atlantic Marine Demarcation

Over the last decade, national authorities and European administrations have made great efforts to establish methodological standards for the assessment of underwater continuous noise, especially under the requirements set by the Marine Strategy Framework Directive (MSFD). Through the MSFD implementation across EU Member States Marine Reporting Units (MRUs), it is intended to establish the Good Environmental Status (GES) whether it is achieved or not. The evaluation of the Sound Pressure Level (SPL) at the local or regional scale for 1/3 octave band of 63 Hz and 125 Hz and the identification of long temporary trends were considered to be a priority due to the valuable information they can offer in relation to continuous low-frequency noise. Nevertheless, the methodology to determine threshold values from which to evaluate the GES has become difficult to define, and new approaches and considerations are currently being discussed by groups of experts, such as the technical subgroup on underwater acoustics (TGnoise) and regional commissions (e.g., OSPAR). This work presents a methodology to perform the assessment of a given area, providing a risk index that is related to potential appearance of masking effect due to the underwater noise produced by marine traffic. The risk index is hinged on the calculation of area under curves defined by the density of animals and a variable related to underwater noise SPL, defined as percentage of communication distance reduction. At this stage, the methodology presented does not consider physiological or behavioral mechanisms to overcome the masking by animals. The methodology presented has been applied to the bottlenose dolphin (Tursiops truncatus) inhabiting the ABIES—NOR marine demarcation to illustrate the possible use of risk-based models to manage marine areas related to human pressures, such as marine traffic, with the potential adverse impact on a given species (e.g., masking effect).En prens

Design and Performance of a Metal-Shielded Piezoelectric Sensor

[EN] In certain circumstances when acoustic measurements are required in the presence of explosive atmospheres the sensor must be placed inside a Faraday Cage. Piezoelectric active materials are suitable for this purpose as they do not need an electrical power supply, although the metal shielding can considerably reduce sensor sensitivity, which is already low at the acoustic frequency range (<20 kHz). This paper describes a metal-shielded piezoelectric sensor designed to work in the range of frequencies between 1 and 2 kHz and in these environmental conditions. The main idea was to add a thin material layer to the front face of the piezoelectric ceramic in order to force the system to vibrate in flexure mode at low frequencies. The resonant frequency and sensitivity of the system was studied as a function of the radius, thickness, and material of the thin layer. The study includes a comparison of theoretical model, FEM simulation, and real data measured using three aluminum and three steel prototypes of different sizes.The author acknowledges financial support from Plan Estatal de Investigacion, ref. FPA2015-231 65150-C3-2-P (MINECO/FEDER), Programa para la promocion de empleo joven e implantacion de la garantia juvenil en I+D+i (PEJ-2014-A-66083), and Generalitat Valenciana AICO2016-108.cSáenz De Inestrillas Jiménez, A.; Camarena Femenia, F.; Bou Cabo, M.; Barreiro-Pérez, JM.; Reig Fabado, A. (2017). Design and Performance of a Metal-Shielded Piezoelectric Sensor. Sensors. 17(1284):1-10. https://doi.org/10.3390/s17061284S11017128