Encontrados 8 documentos, a visualizar página 1 de 1
Ocean noise field-calibration constraints for deep sea mining
de Oliveira Júnior, Luciano; Rodríguez, Orlando; Jesus, SergioThe EU Horizon project TRIDENT aims at developing a comprehensive study to improve the understanding of the activities related to deep sea mining as well as to develop observation methodologies, technologies required for impact forecast, and possible mitigation measures. In the framework of TRIDENT, the impact of the acoustic field will be assessed by deploying a fixed array of acoustic recorders in the surroun...
Search space reduction for localization and tracking of an acoustic source
Rodríguez, Orlando; Zhang, Lilun; Cheng, XinghuaExperimental data from the SACLANTCEN 1993 Mediterranean Experiment are reviewed to assess the reduction of the search space for the localization and tracking of an acoustic source in a three-dimensional environment. Key to this goal is the availability of an initial estimate of source range and depth (called the 2D initial guess); an ambiguous estimate of source bearing can be obtained from the 2D initial gues...
Fundamentos de acústica submarina
Rodríguez, OrlandoA Acústica Submarina é uma área de investigação excepcionalmente interdisciplinar, que pela primeira vez encontra nesta obra um espaço de expressão em língua portuguesa; trata-se de uma obra que condensa 30 anos de investigação por parte do autor e investigadores associados da UALG, e que pretende servir como referência para o desenvolvimento de aplicações nas áreas de investigação que recorrem aos métodos da A...
TRACEO3D Ray tracing model for underwater noise predictions
Calazan, Rogério; Rodríguez, OrlandoShipping noise is the main source of underwater noise raising concern among environmental protection organizations and the scientific community. Monitoring of noise generated by shipping traffic is a difficult challenge within the context of smart systems and solutions based on acoustic modeling are being progressively adopted to overcome it. A module of sound propagation stands as a key point for the developme...
Parallel ray tracing for underwater acoustic predictions
Calazan, Rogério; Rodríguez, Orlando; Nedjah, NadiaDifferent applications of underwater acoustics frequently rely on the calculation of transmissions loss (TL), which is obtained from predictions of acoustic pressure provided by an underwater acoustic model. Such predictions are computationally intensive when dealing with three-dimensional environments. Parallel processing can be used to mitigate the computational burden and improve the performance of calculati...
Monitoring bubble production in a seagrass meadow using a source of opportunity
Felisberto, Paulo; Rodríguez, Orlando; Silva, João P.; Jesus, Sergio; Ferreira, Hugo Q.; Ferreira, Pedro P.; Cunha, Maria E.; de los Santos, Carmen B.Under high irradiance, the photosynthetic activity of dense seagrass meadows saturates the water forming oxygen bubbles. The diel cycle of bubble production peaks at mid-day, following light intensity pattern. It is well known that bubbles strongly affect the acoustic propagation, increasing signal attenuation and decreasing the effective water sound speed, noticeable at low frequencies. Thus, the diurnal varia...
Kernel-function-based models for acoustic localization of underwater vehicles
Pinheiro, Breno C.; Moreno, Ubirajara F.; de Sousa, Joao T. B.; Rodríguez, OrlandoThis paper proposes a novel design for the localization system of autonomous underwater vehicles (AUVs) using acoustic signals. The solution presented exploits models based on kernel functions with two main purposes: 1) to reject outliers; and 2) to correct or improve accuracy of measurements. The localization system discussed is based on well-established techniques such as support vector data description (SVDD...
The TV-APM interface: a web service for collaborative modelling
Rodríguez, Orlando; Silva, António J.; Zabel, Friedrich; Jesus, S. M.Current development of Internet access, together with available zero-cost Open Source applications (like, for instance, PHP, Python, etc.) can be integrated in order to minimize the constrains induced by the geographical separation of international centers, which collaborate in a given project. The advantage of such approach lies in the sharing of common analysis methods, without particular constrains to specif...