Satellite SAR interferometry for monitoring dam deformation in Portugal

The paper offers three examples of satellite SAR interferometry (InSAR) application for monitoring dam deformations: Paradela, Raiva and Alto Ceira, all of them in Portugal. Dam deformations were estimated using several sets of ERS and Envisat C-band SAR data by PS-InSAR method that offers accuracy of a millimeter per year at monitoring man-made tructures. The results show potential of InSAR but also summarize limits of C-band InSAR in these particular cases and can be handful to recognize applicability of new Sentinel-1 data (since 2014) for continuous monitoring of dam deformations. While Alto Ceira dam lies in SAR radar shadow and was represented by only one observable point, and the movement detected (in satellite line-of-sight direction) appears to fit with geodetical measurements. Raiva and Paradela dams were represented by sufficient number of points feasible for PS-InSAR processing. Deformations at slope near to Raiva dam and slow linear movements of the center of Paradela dam were detected

Multi-temporal SAR Interferometry for Monitoring of Man-Made Sfructures.

Multi-temporal InSAR (MTI) methods are effective tools for monitoring and investigating surface displacement on Earth based on conventional radar interferometry. These techniques allow us to measure deformation with uncertainties up to one millimeter per year, interpreting time series of interferometric phases at coherent/stable point scatterers. Considering the regular revisit time and wide-area coverage of satellite radar sensors, and that stable points usually correspond to buildings and other man-made structures, these techniques are particularly suitable for application in urban environments. In this paper we present some examples of the application of MTI techniques to study the stability of port structures and one example of dam monitoring. These promising results make it possible to think in the development of an interferometric methodology using the new high-resolution synthetic aperture radar satellites scenes for structural health monitoring

aplicabilidade do modelo Servqual na restauração de um aldeamento turístico

Dissertação de Mestrado , Ciências Económicas e Empresariais, Faculdade de Economia, Universidade do Algarve, 2008No actual contexto económico urge a necessidade das organizações reflectirem e consciencializarem-se de que o facto de prestar serviços de qualidade, visando a plena satisfação do cliente, se torna um dos factores impreteríveis para se conseguir não só sobreviver, como também expandir num mercado gradualmente mais exigente e competitivo. Com o objectivo de quantificar as dimensões associadas à satisfação global do cliente no contexto da restauração num aldeamento turístico, foi efectuado um estudo de natureza exploratória, que teve por base uma amostra de 300 indivíduos. Recorrendo-se a um instrumento de medição da qualidade nos serviços, designado por modelo SERVQUAL, seleccionaram-se dois segmentos de restauração, nomeadamente o A e o B, onde foram inquiridos 150 indivíduos em cada um deles. No tratamento estatístico utilizou-se a análise factorial como método de extracção de factores, no sentido de analisar quais as dimensões da satisfação do cliente e a regressão linear múltipla para quantificar a contribuição dos diversos factores na sua satisfação global. A análise factorial permitiu-nos identificar vários factores, nomeadamente a fiabilidade, a funcionalidade, a tangibilidade, a personalização, a prontidão, as aptidões técnicas, a empatia, o comportamento e a disponibilidade como sendo dimensões da satisfação do cliente na restauração. A aplicação do modelo de regressão linear múltipla, no caso em estudo permitiu-nos concluir que são consideradas variáveis não significativas as que estão relacionadas com as características das instalações, existindo uma preocupação acrescida com as variáveis de natureza relacional. Deste modo, a importância que o cliente confere aos aspectos relacionais sugere o desenvolvimento incontestável de acções de formação profissional, com particular incidência nas questões relacionais associadas à prestação de serviços.In the current economic context, the organizations need to be aware that to survive and expand in a market gradually more demanding and competitive, it is imperative to achieve the best quality of services and consequent full client’s satisfaction. In order to quantify the customer’s satisfaction about a restaurant village resort, we studied 300 individuals (sample). The instrument used to measure the services quality was the model SERVQUAL. Two restaurant segments, A and B, were selected and 150 people were surveyed in each one. The statistical treatment included factorial analysis as a method of factor extraction to analyse customer’s satisfaction. It was also used multiple linear regression to quantify the contribution of different factors in the clients overall satisfaction. The factorial analysis enabled us to identify several factors, including the reliability, functionality, tangibility, customization, readiness, technical skills, empathy, the performance and availability as dimensions of customer satisfaction. The multiple linear regression models allowed us to conclude, in this case, that the accommodations characteristics are considered non-significant variables. However, there was an increased concern with the human relationships variables. Thus, the importance given to relational aspects suggests the urgent need of developing professional training, focusing on services providing

viStaMPS: The InSAR collaborative project

The viStaMPS software is a collaborative scientific project that was created with three major purposes: (1) facilitate the usage by users non familiar with the specificities of the programming language that supports StaMPS; (2) implement several visualization tasks not available in the StaMPS standard approach (avoiding that each user develop its own code for visualization and interpretation purposes) and (3) create a collaborative research project, continuously under development counting on the dynamism of its users to improve and/or add new features.The authors acknowledge the European Space Agency (ESA) for providing the ERS-SAR images, used to create the figures, under the Cat-1 Project ID 9981.info:eu-repo/semantics/publishedVersio

Potential of Multi-temporal InSAR Techniques for Bridges and Dams Monitoring

AbstractThe aim of this paper is twofold. Firstly, to present a survey of the actual and most advanced methods for man-made structures monitoring, more specifically dams and bridges. Theoretical and technical aspects of these methodologies are presented and discussed focusing on innovative inspection methods and on the opportunities that could deliver. Secondly, to identify the opportunities that could potentially improve the inspections and maintenance processes, being the satellite-based monitoring, using radar imagery, recognized as viable source of independent information products that may be used to remotely monitor the health of these specific man-made structures. By applying Multi-temporal InSAR processing techniques to a series of radar images over the same region, it is possible to detect vertical movements of structure systems on the ground in the millimeter range, and therefore, identify abnormal or excessive movement indicating potential problems requiring detailed ground investigation. In this paper it is clearly demonstrated that with the new high-resolution synthetic aperture radar satellites scenes, InSAR technology may be particular useful as hot spot indicator of relative deformations structures over large areas, making possible to develop interferometric based methodologies for structural health monitoring. From a technological standpoint, this approach represents a substantial evolution over the current state-of-the-art

ATLANTIC ANTS: a data set of ants in Atlantic Forests of South America

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