Percorrer por autor "Faria, Carlos"
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- Network nodes for ocean data exchange through submarine fiber optic cable repeatersPublication . Martins, M. S.; Cruz, Nuno A.; Silva, António; Ferreira, Bruno; Zabel, Fred; Matos, Tiago; Jesus, Sergio; Pinto, André; Pereira, Eduardo; Matos, Aníbal; Faria, Carlos; Tieppo, Marcos; Goncalves, L. M.; Rocha, João; Faria, JoãoAs humanity progresses and globalization advances, humanized environment and associated systems increase in complexity and size. In earth systems, oceans represent an essential element of equalization and normal functioning. Ocean-atmospheric interactions are nowadays believed to be at the heart of all earth vital signs and climatic behaviours, and therefore are essential to accurate monitoring and understanding of earth systems. The work presented is a preliminary result of the K2D- Knowledge and Data from the Deep to Space, project which addresses the challenge of creating underwater network nodes to provide power and communication to land through the submarine fiber optic cable repeaters. The N2ODE system will consist of a set of subsystems that will allow continuous monitoring and interaction with fixed and mobile underwater devices.
- Wideband and wide beam polyvinylidene difluoride (PVDF) acoustic transducer for broadband underwater communicationsPublication . Martins, Marcos; Faria, Carlos; Matos, Tiago; Gonçalves, Luís; Cabral, José; Silva, António; Jesus, SergioThe advances in wireless communications are still very limited when intended to be used on Underwater Communication Systems mainly due to the adverse proprieties of the submarine channel to the acoustic and radio frequency (RF) waves propagation. This work describes the development and characterization of a polyvinylidene difluoride ultrasound transducer to be used as an emitter in underwater wireless communications. The transducer has a beam up to 10° × 70° degrees and a usable frequency band up to 1 MHz. The transducer was designed using Finite Elements Methods and compared with real measurements. Pool trials show a transmitting voltage response (TVR) of approximately 150 dB re µPa/V@1 m from 750 kHz to 1 MHz. Sea trials were carried in Ria Formosa, Faro (Portugal) over a 15 m source-receiver communication link. All the signals were successfully detected by cross-correlation using 10 chirp signals between 10 to 900 kHz.
