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

Unmanned Vehicle Systems & Operations on Air, Sea, Land

Unmanned Vehicle Systems & Operations On Air, Sea, Land is our fourth textbook in a series covering the world of Unmanned Aircraft Systems (UAS) and Counter Unmanned Aircraft Systems (CUAS). (Nichols R. K., 2018) (Nichols R. K., et al., 2019) (Nichols R. , et al., 2020)The authors have expanded their purview beyond UAS / CUAS systems. Our title shows our concern for growth and unique cyber security unmanned vehicle technology and operations for unmanned vehicles in all theaters: Air, Sea and Land – especially maritime cybersecurity and China proliferation issues. Topics include: Information Advances, Remote ID, and Extreme Persistence ISR; Unmanned Aerial Vehicles & How They Can Augment Mesonet Weather Tower Data Collection; Tour de Drones for the Discerning Palate; Underwater Autonomous Navigation & other UUV Advances; Autonomous Maritime Asymmetric Systems; UUV Integrated Autonomous Missions & Drone Management; Principles of Naval Architecture Applied to UUV’s; Unmanned Logistics Operating Safely and Efficiently Across Multiple Domains; Chinese Advances in Stealth UAV Penetration Path Planning in Combat Environment; UAS, the Fourth Amendment and Privacy; UV & Disinformation / Misinformation Channels; Chinese UAS Proliferation along New Silk Road Sea / Land Routes; Automaton, AI, Law, Ethics, Crossing the Machine – Human Barrier and Maritime Cybersecurity.Unmanned Vehicle Systems are an integral part of the US national critical infrastructure The authors have endeavored to bring a breadth and quality of information to the reader that is unparalleled in the unclassified sphere. Unmanned Vehicle (UV) Systems & Operations On Air, Sea, Land discusses state-of-the-art technology / issues facing U.S. UV system researchers / designers / manufacturers / testers. We trust our newest look at Unmanned Vehicles in Air, Sea, and Land will enrich our students and readers understanding of the purview of this wonderful technology we call UV.https://newprairiepress.org/ebooks/1035/thumbnail.jp

Optimization of flexible spectrum in optical transport networks

The ever-increasing demand for broadband services by end-user devices utilising 3G/4G/LTE and the projected 5G in the last mile will require sustaining broadband supply from fibre-linked terminals. The eventual outcome of the high demand for broadband is strained optical and electronic devices. The backbone optical fibre transport systems and techniques such as dense wavelength division multiplexing (DWDM), higher modulation formats, coherent detection and signal amplification have increased both fibre capacity and spectrum efficiency. A major challenge to fibre capacity and spectrum efficiency is fibre-faults and optical impairments, network management, routing and wavelength assignment (RWA). In this study, DWDM and flexible spectrum techniques such as wavelength assignment and adjustment, wavelength conversion and switching, optical add and drop multiplexing (OADM) and bitrate variable transmission have been experimentally optimized in a laboratory testbed for short- and long-haul optical fibre networks. This work starts by experimentally optimising different transmitters, fibre-types and receivers suitable for implementing cost effective and energy efficient flexible spectrum networks. Vertical cavity surface-emitting lasers (VCSELs) and distributed feedback (DFB) lasers have been studied to provide up to 10 Gb/s per channel in 1310 nm and 1550 nm transmission windows. VCSELs provide wavelength assignment and adjustment. This work utilises the non-return-to-zero (NRZ) on-off keying (OOK) modulation technique and direct detection due to their cost and simplicity. By using positive intrinsic negative (PIN) photo-receivers with error-free BER sensitivity of -18±1 dBm at the acceptable 10-9-bit error rate (BER) threshold level, unamplified transmission distances between 6 km and 76 km have been demonstrated using G.652 and G.655 single mode fibres (SMFs). For the first time, an all optical VCSEL to VCSEL wavelength conversion, switching, transmission at the 1550 nm window and BER evaluation of a NRZ data signal is experimentally demonstrated. With VCSEL wavelength conversion and switching, wavelength adjustments to a spectrum width of 4.8 nm (600 GHz) can be achieved to provide alternative routes to signals when fibre-cuts and wavelength collision occurs therefore enhancing signal continuity. This work also demonstrates a technique of removing and adding a wavelength in a bundle of DWDM and flexible channels using an OADM. This has been implemented using a VCSEL and a fibre Bragg grating (FBG) providing a wavelength isolation ratio of 31.4 dB and ~0.3 add/drop penalty of 8.5 Gb/s signal. As a result, an OADM improves spectrum efficiency by offering wavelength re-use. Optical impairments such as crosstalk, chromatic dispersion (CD) and effects of polarization mode dispersion (PMD) have been experimentally investigated and mitigated. This work showed that crosstalk penalty increased with fibre-length, bitrate, interfering signal power and reduced channel spacing and as a result, a crosstalk-penalty trade-off is required. Effects of CD on a transmitted 10 Gb/s signal were also investigated and its mitigation techniques used to increase the fibre-reach. This work uses the negative dispersion fibres to mitigate the accumulated dispersion over the distance of transmission. A 5 dB sensitivity improvement is reported for an unamplified 76 km using DFB transmitters and combination of NZDSF true-wave reduced slope (TW-RS) and submarine reduced slope (TW-SRS) with + and – dispersion coefficients respectively. We have also demonstrated up to 52 km 10 Gb/s per channel VCSEL-based transmission and reduced net dispersion. Experimental demonstration of forward Raman amplification has achieved a 4.7 dB on-off gain distributed over a 4.8 nm spectral width and a 1.7 dB improvement of receiver sensitivity in Raman-aided 10 Gb/s per wavelength VCSEL transmission. Finally, 4.25-10 Gb/s PON-based point to point (P2P) and point to multipoint (P2MP) broadcast transmission have been experimentally demonstrated. A 10 Gb/s with a 1:8 passive splitter incurred a 3.7 dB penalty for a 24.7 km fibre-link. In summary, this work has demonstrated cost effective and energy efficient potential flexible spectrum techniques for high speed signal transmission. With the optimized network parameters, flexible spectrum is therefore relevant in short-reach, metro-access and long-haul applications for national broadband networks and the Square Kilometre Array (SKA) fibre-based signal and data transmission