Browsing by Author "Lopes, C."
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- An autonomous system for ocean acoustic tomographyPublication . Felisberto, P.; Lopes, C.; Jesus, S. M.Vertical line arrays (VLA) are a widely used apparatus in underwater acoustics with applications in sonar prediction, underwater communications and acoustic tomography, among others. Recent developments in digital electronics and communications allow for off-the-shelf development of VLA systems, with a large number of embedded acoustic and non-acoustic sensors able to fulfill application requirements, as opposed to single or few receiver configurations available until only a few years ago. Very often, the flexibility in water column sampling is achieved by splitting the VLA into modules that can be assembled according to the application. Such systems can be deployed and recovered from small vessels with a shorthanded crew, and make it possible for research labs with reduced budgets and operational means (ships and manpower) to gain control over the whole development process, from data acquisition to post-processing.
- Data acquisition and monitoring system (DAMS)Publication . Lopes, C.; Soares, C.In order to achieve specific requirements of their research programs under projects INTIMATE and INFANTE, a consortium formed by the Centro de Investigação ̧Tecnológica do Algarve (CINTAL), the Instituto Hidrográfico (IH) and the Instituto Superior Técnico (IST) have purchased an acoustic tomography and underwater communication system to the company CO.L.Mar. This system is composed of two hydrophone arrays, one surface buoy, one RF link and other electronic and mechanical devices, that can be referred to as distinct categories: • the Wet-end system and • the Dry-end system depending on their position when deployed. The Data Acquisition & Monitoring System ( DAMS ) described in this report connects to the Dry-end of Colmar’s tomographic system (as shown in figure 1) and provides the following capabilities: i) to read and monitor the data being acquired, ii) to demultiplex and store the data on digital format and iii) to provide absolute time-marking of the data for future use.In order to achieve specific requirements of their research programs under projects INTIMATE and INFANTE, a consortium formed by the Centro de Investigação ̧Tecnológica do Algarve (CINTAL), the Instituto Hidrográfico (IH) and the Instituto Superior Técnico (IST) have purchased an acoustic tomography and underwater communication system to the company CO.L.Mar. This system is composed of two hydrophone arrays, one surface buoy, one RF link and other electronic and mechanical devices, that can be referred to as distinct categories: • the Wet-end system and • the Dry-end system depending on their position when deployed. The Data Acquisition & Monitoring System ( DAMS ) described in this report connects to the Dry-end of Colmar’s tomographic system (as shown in figure 1) and provides the following capabilities: i) to read and monitor the data being acquired, ii) to demultiplex and store the data on digital format and iii) to provide absolute time-marking of the data for future use.
- Diatoms Si uptake capacity drives carbon export in coastal upwelling systemsPublication . Abrantes, Fatima; Cermeno, Pedro; Lopes, C.; Romero, Oscar; Matos, Lelia; Van Iperen, Jolanda; Rufino, Marta; Magalhaes, VitorCoastal upwelling systems account for approximately half of global ocean primary production and contribute disproportionately to biologically driven carbon sequestration. Diatoms, silica-precipitating microalgae, constitute the dominant phytoplankton in these productive regions, and their abundance and assemblage composition in the sedimentary record is considered one of the best proxies for primary production. The study of the sedimentary diatom abundance (SDA) and total organic carbon content (TOC) in the five most important coastal upwelling systems of the modern ocean (Iberia-Canary, Benguela, Peru-Humboldt, California, and Somalia-Oman) reveals a global-scale positive relationship between diatom production and organic carbon burial. The analysis of SDA in conjunction with environmental variables of coastal upwelling systems such as upwelling strength, satellite-derived net primary production, and surface water nutrient concentrations shows different relations between SDA and primary production on the regional scale. On the global scale, SDA appears modulated by the capacity of diatoms to take up silicic acid, which ultimately sets an upper limit to global export production in these ocean regions.
- Improving vector-borne disease control in AlbufeiraPublication . Sá, R.; Dinis, V.; Edmundo, A.; Costa, I. Carvalho; Figueiredo, V.; Almeida, S.; Fonseca, A.; Lopes, C.; Rodrigues, V.; Correia, M.The Albufeira Health Centre (CSA) comprises various functional units within primary healthcare. Recognizing the limited awareness of colleagues regarding the Vector Surveillance Network (REVIVE), responsible for entomological surveillance of mosquitoes, ticks, and sandflies, the Public Health Unit (USP) initiated a project to improve coordination and knowledge sharing. Implemented in April 2023, the project involved a multidisciplinary team. Informational materials on vector surveillance and control, clinical guidance for common vector-borne diseases (VBDs), tick collection protocols, and specimen registration forms were distributed. A video highlighting entomological surveillance and strategies for prevention and control was disseminated. To date, the project has recorded 45 views of the video (51%). A questionnaire distributed among the target population revealed that only 20% had knowledge of the epidemiological importance of vectors in the Algarve region. None were familiar with REVIVE or its work. Furthermore, participants were not acquainted with the Aedes albopictus mosquito species. Regarding ticks, 20% felt confident in tick removal, but none were aware of the tick genera in the Algarve region. Only 20% were aware of notifiable vector-borne diseases through SINAVE. Training sessions on this topic were suggested. The project emphasized the significance of communication and collaboration among healthcare professionals in the prevention and control of vector-borne diseases. It highlighted the need for continuous education on VBDs, surveillance techniques, and control measures. This innovative project can serve as a model for healthcare centres and countries, contributing to global efforts to improve the response to vector-borne diseases. The project's outreach extended to the Municipal Albufeira Animal Welfare Centre. A new questionnaire will be distributed to gather additional insights and enhance the impact of the project.
- The INTIFANTE'00 sea trial: preliminary source localization and ocean tomography data analysisPublication . Jesus, S. M.; Coelho, E.; Onofre, J.; Picco, P.; Soares, C.; Lopes, C.The INTIFANTE'00 sea trial was a multidisciplinary experiment including testing of an autonomous surface vehicle, underwater communications, source localization and acoustic ocean tomography. The results shown here will concentrate on the source localization and ocean tomography data sets. The data gathered during a 24 hour run along a range independent track shows strong oceanographic features, possibly due to internal tide signature, both on the temperature data, as measured on the thermistor chain collocated with a vertical line array(VLA), and on the acoustic data. A range dependent track between 120 and 60 m water depth, shows a highly variable channel impulse response along time and range when the source was moving outwards from the VLA. In another acoustic track, the source was navigatated across a underwater canyon where the energy was rapidly distributed over a deep acoustic channel with sound trapped well below the thermocline. Good agreement between the modeled and measured channel responses represents the rst step towards matched- eld processinglike methods such as source localization and tracking and ocean tomography.
- Ultra light vertical array remote data acquisition system (ULVA RDAS)Publication . Felisberto, P.; Lopes, C.; Carmo, A.In 1997, CINTAL has requested Co.L.Mar Srl. (Italy) to provide the plans and the execution for a multichannel Ultra Light Vertical Array (ULVA) underwater acoustic passive system to support its research plans under project INTIMATE (FCT contract 2/2.1/MAR/1698/95). The solution proposed by Co.L.Mar was composed of a vertical line array (VLA) with 16 hydrophones, a radio buoy with an RF data link to a base station, interfaced to a DAT recorder. Under the same project, CINTAL has developed a PC based system that interfaced to the RF receiver on the base station would allow to acquire on computer disk and monitor the signals being received on line - this is the Data Acquisition and Monitoring System (DAMS). The ensemble composed of the receiving array, the RF link and the PC monitoring system will referred to in this report as the ULVA/DAMS system. The ULVA/DAMS system was first tested at sea in July 1999 and then sucessfully operated during the INTIFANTE 00 sea trial in October 2000.