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Para entender e monitorar adequadamente os riscos decorrentes de processos deformantes, como a subsidência, é fundamental identificá-los e avaliar sua magnitude adequadamente. O uso do GNSS é amplamente difundido para avaliar o panorama geral dessas instabilidades, seja por meio de posições absolutas ou medições contínuas dos pontos dentro das áreas afetadas. Por outro lado, a técnica interferométrica em uma abordagem multi-temporal (MT-InSAR), como a técnica PSInSAR, permite monitorar e detectar pequenas variações no terreno causadas por movimentos da superfície, como deslizamentos de terra ou subsidência. Nesse sentido, este manuscrito tem como objetivo complementar os resultados de uma análise de subsidência por meio de observações GPS realizadas em uma região do bairro Guabirotuba, em Curitiba (PR), utilizando o processamento interferométrico empregando a técnica PSInSAR com base em 77 imagens SAR do satélite Sentinel-1A, adquiridas na órbita descendente durante o período de 2016 a 2022. Os resultados revelaram que as estações da rede GPS implantada no Guabirotuba apresentaram uma velocidade extremamente lenta quando projetadas na direção da linha de visada (LoS) do satélite. A projeção na LoS dos deslocamentos relativos das coordenadas (north, east, up) e das velocidades apresentou comportamentos semelhantes e, em alguns pontos, divergentes quando comparados aos resultados obtidos com a técnica PSInSAR.

This work is carried out with the purpose of studying theoretically the measurement of the diffusion coefficient (DC) in liquid substances using double exposure holographic interferometry (DEHI). Diffusion has been defined, throughout history, as the phenomenon in which matter moves in a system, from regions with high concentrations to those regions where the concentration is lower, as a consequence of the random movements of its molecules. Diffusion proceeds gradually in the mixture of substances, ending just when the concentrations are equalized; in the case of liquid phase substances, the diffusion of a solute in a solvent. For the study of this process, multiple techniques have been used, among which the optical ones stand out, specifically holographic interferometry, which associates the precision of interferometric measurements with the advantages of holography; by implementing IHDE, it is possible to compare the wavefronts, which in principle were separated in time, thus allowing any type of variation in the analyzed object, however small, to be determined by knowing the characteristic wavelength of the light used. In this article, the theoretical development is presented to obtain the mathematical expression from which the CD in liquids can be calculated, using IHDE, highlighting that this is found through the comparison between interferential fringes of the same order recorded at different times, taking into account the distances, measured from the interface between the two liquids, at which they appear. Finally, an analysis of the expression found and how it is applied from experimentally obtained data is carried out. [ABSTRACT FROM AUTHOR]

Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR™) é uma técnica de sensoriamento remoto que usa como base a técnica Differential InSAR (DInSAR), porém, emprega uma série de interferogramas diferenciais advindas de uma pilha de imagens Single Look Complex - Synthetic Aperture Radar (SLC-SAR) devidamente corregistradas e adquiridas em um intervalo de tempo sobre uma mesma área para, de tal modo, selecionar pixels que apresentam um índice de dispersão da amplitude dentro de um limiar estabelecido e, assim, gerar uma série histórica de deslocamento da superfície. A PSInSAR™ usa pixels que contenham dispersores persistentes que são caracterizados por obras de engenharia como pontes, taludes, telhados, casas, prédios, e algumas feições naturais como rochas. Por meio da análise da fase desses pixels, a PSInSAR™ consegue superar algumas dificuldades encontradas com a DInSAR, tais como, problemas correlacionados com a falta de correlação atmosférica, temporal e espacial. Desde a sua idealização no início dos anos de 2000 e devido a sua capacidade de mapear deslocamentos superficiais a uma acurácia milimétrica, a PSInSAR™ vem sendo amplamente usada em estudos sobre subsidências, deslizamentos, monitoramento de barragens, monitoramento de minas e de estruturas de engenharia no modo geral. Nesse sentido, o presente artigo descreve o princípio básico de funcionamento da técnica, investiga a sua aplicabilidade no âmbito nacional e internacional e apresenta os pacotes de processamento existentes no mercado assim como o acesso de dados interferométricos que possibilitam à utilização da PSInSAR™.

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Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Subsidence is a highly destructive natural hazard, which can be caused by both natural and anthropogenic causes. Its impacts include the creation of cracks and fissures, damages to buildings and infrastructures, a decrease in storage capacity of aquifer systems, and an increase of the susceptibility to flooding. In this study, Persistent Scattered Interferometry (PSI) has been used to process Synthetic Aperture Radar (SAR) images, for the detection and analysis of ground deformation and subsidence processes in the island of Mallorca. The study database is composed of 120 images captured by the Sentinel 1A and 1B satellites (between May 2016 and December 2019), from which we derived a map of accumulated displacement rates occurred during a 3 years and a half period. The results show important subsidence processes of up to 30 mm year-1 in large areas of the sedimentary basin of Palma, and of lesser magnitude (between 10 and 20 mm year-1) in locations of the Central Depression and in basins in the Serra de Tramuntana, such as the Torrent Major at Sóller and the Torrent de Gorg Blau. A significant relationship has also been observed between the thickness of the Quaternary sediment and the observed subsidence rates. The results highlight the high degree of geomorphological dynamism at very short time scales that characterizes Mallorca, and the vulnerability of certain urban areas, such as the city of Palma (? 400000 inhabitants), and agricultural areas, such as the Central Depression, facing the risk of subsidence and associated damages. [ABSTRACT FROM AUTHOR]

In this contribution, DInSAR analysis, seismic/brittle strain rates, and seismic uplift estimations were used to evaluate ground deformation patterns of the 24 December 2019 Mw 5.8 Mesetas Earthquake that occurred in the Mesetas municipality (Meta, Colombia), on the eastern foothills of Colombian's Eastern Cordillera, near the Serranía de la Macarena. According to the focal mechanisms computed for this earthquake, the right-lateral Algeciras Fault System was responsible for the rupture event. Primary and secondary SAR images from December 18/2019 and 30/2019, respectively, were used to calculate coseismic ground deformation of the study area. Geocoded line-of-sight (LOS) displacement image suggests that major ground deformation was on the order of 0.2 m for the 24 December discrete seismic event, while the accumulated seismic contribution to surface uplift during 1993 to 2020 reached values of ca. 0.14 m/yr. In contrast, seismic/brittle strain rates and seismic uplift estimations show that this part of South America is currently experiencing deformation at a rate of 4.1×10-16 ± 1.7×10-17s-1 and uplift at a rate of 81.5 ± 3.4 m/Ma during 2018-2020, whereas the deformation was 0.1×10-16 ± 0.2 ×10-17s-1 at a rate of 2.2 ± 0.5 m/Ma between 1993-2018. [ABSTRACT FROM AUTHOR]

La ciudad de Morelia, en la zona central de México, ha sido afectada en años recientes por la subsidencia diferencial del suelo que se refleja en forma de fallas y fracturas en la superficie. El objetivo de este trabajo es el obtener series de tiempo de la deformación del suelo utilizando interferogramas InSAR, con el fin de determinar la evolución espacial y temporal de la subsidencia en la ciudad de Morelia. Con este fin se procesaron 28 imágenes de ENVISAT-ASAR, adquiridas de mayo de 2003 a septiembre de 2010. Se limitaron las líneas de base perpendiculares y temporales a ser menos de 400 m y 420 días respectivamente, como un criterio de calidad para seleccionar los interferogramas. De un total de 378 interferogramas, se consideró que únicamente 65 tenían la suficiente calidad para ser usados en la inversión, basado en la decorrelación obervada en las señales. Los resultados muestran que la mayor parte de la ciudad de Morelia no está afectada por subsidencia del suelo de manera significativa. En areas donde si hay subsidencia del terreno, las velocidades varían de 0.7 a 5 cm/año. La mayor subsidencia se da en forma de estructuras circulares y a lo largo de algunas de las fallas observadas en la superficie. La subsidencia del terreno está concentrada en áreas específicas al pie de la fallas La Colina, Central Camionera y La Paloma. Sin embargo, la subsidencia no es continua a lo largo de estas fallas y se observa únicamente en segmentos específicos de las mismas. En algunos casos, como por ejemplo la falla La Paloma, la subsidencia parece estar asociada con fuertes cambios litológicos entre el techo y el piso de las fallas. En otros casos, como en las fallas Central Camionera y La Colina, la subsidencia diferencial observada parece estar asociada a la compleja estructura del basamento y del subsuelo de la ciudad de Morelia, y relacionada primordialmente con la compactación diferencial de los sedimentos de la cuenca. doi: https://doi.org/10.22201/igeof.00167169p.2018.57.1.1821

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In this work, an easy to understand optical system was developed for the study of the medical imaging technique optical coherence tomography (OCT). This technique allows volumetric reconstruction of inhomogeneous, non-transparent and scattering samples such as biological tissues. The implementation was based on using non-specialized components for OCT under the scheme of a Michelson interferometer with a CCD camera to capture the interference patterns in a configuration known as full field OCT (FFOCT). Our system, explained in detail, was designed using components commonly found in most optical labs because our focus is to provide an accessible experimental setup for understanding the basics of OCT. The developed system possesses an axial resolution of 1.74 μm and a lateral resolution of 4.5 μm. With the described system, tomograms of two samples were obtained: a metal coin and an ex-vivo insect wing of the blattodea. [ABSTRACT FROM AUTHOR]

In this work, we present a comparative study between two notorious techniques for wavefront characterization: Shack-Hartmann wavefront sensor and the Point-Diffraction Interferometer. The main goal of this work is to experimentally demonstrate the equivalence of results when wavefront characterization measurements are carried out for both techniques, within the experimental error, in the case of imaging systems. The study has been carried out in several commercial convergent lenses obtaining small root-mean-square difference between both techniques. The results aim the possibility to design a dual set-up combining both techniques with potential use in Ophthalmic applications. [ABSTRACT FROM AUTHOR]

Carajás Mineral Province, Amazon region, is the most important one in Brazil. Vale S.A. Company has the right to operate in the area of the N5E mine. The work is conducted on rock alteration products of low geomechanical quality related to sandstones, siltstones, and a lateritic cover. In order to monitor ground deformation, 33 TerraSAR-X images covering the period of March 2012– April 2013 were used in the investigation. An interferometric synthetic aperture radar (InSAR) approach based on permanent scatterer interferometry (PSI) using an interferometric point target analysis algorithm was applied. Results demonstrated that most of the area was considered stable during the time span of the image acquisition. However, persistent scatterers (PSs) with high deformation rates were mapped over a landfill probably related to settlements. To validate the PSI data, graphs were generated with the displaced information based on topographic measurements in the field. The graphs showed that the surface deformations during TSX-1 runway coverage are within the miner's safety threshold and do not present a risk of major problems. The PSI data provided a synoptic and detailed view of the deformation process that affects the mining complex without the need of field campaign or instrumentation. [ABSTRACT FROM AUTHOR]

We present an experimental installation for the measurement of deformations of healthy superior premolar teeth implementing the method of projection of fringes. The samples were inserted in polyethylene resin and fixed in support, which has a stem that is responsible for the application of the load, the loads used being of the order of 25 N, 50 N, 75 N and 100 N. Each load was applied along the axis of the tooth by touching its two cusps and then again with the load touching only a cusp. Was developed a computer program supported in MATLAB for the reconstruction of images. The process of digital image reconstruction using the stripe projection method includes: Intensity and phase contrast images and deformation caused by the application of a force on the teeth. For the linearization of the phase was applied the algorithm of Volkov. [ABSTRACT FROM AUTHOR]

En este trabajo se presenta una metodología para la medida de deflexiones en el rango de las micras en membranas termoneumáticas de silicio. El método se basa en la interferometría por fibra óptica con el cual se estudió el comportamiento estático de una membrana de silicio de 10 mm de grosor, 5 mm de lado y 300 mm de bulk, la cual se pegó sobre un porta muestras de vidrio. Por medida estática se entiende la medida de la deflexión de las membranas considerando únicamente la respuesta de éstas a la fuente de radiación infrarroja que las estimula.

Neste trabalho apresentamos a medida do coeficiente linear de dilatação térmica do alumínio, usando o interferograma obtido a partir da transformada de Fourier sobre a soma de duas imagens de speckle deslocadas. O resultado alcançado está em bom acordo com o tabelado e os equipamentos necessários têm custo acessível, tornando o experimento uma alternativa interessante para introdução da metrologia óptica no laboratório didático ou um projeto a ser desenvolvido em disciplinas experimentais.

O objetivo deste trabalho foi estabelecer as relações entre os parâmetros dendométricos de florestas e a resposta da radiometria e da interferometria obtidas por sensores SAR (Synthetic Aperture Radar), utilizando técnicas de regressão multivariada. Uma área de povoamento de Eucalyptus grandis, com 6,1 anos de plantio, foi selecionada para estudo. Os resultados indicaram que o volume das parcelas foi altamente correlacionado com o logaritmo da altura interferométrica (LogHint) obtida pela diferença entre os modelos interferométricos nas bandas X e P, enquanto que o DAP (Diâmetro à Altura do Peito) apresentou melhor relação com a combinação da coerência interferométrica na banda PVV (CohPVV) e o LogHint. A altura comercial da vegetação, similarmente ao DAP, foi melhor explicada com a combinação da CohPvv e o LogHint. Os resultados obtidos demonstraram que, devido ao povoamento ser constituído de indivíduos cuja estrutura era predominantemente cilíndrica de orientação vertical, houve uma maior interação com a polarização VV. Os resultados indicaram também que a resposta radiométrica na banda P, de maior comprimento de onda, não foi tão eficaz quanto a interferometria (CohPvv e o LogHint) para estimativa dos parâmetros dendométricos estudados, obtendo índices de determinação de 84 a 88% em relação ao inventário florestal das áreas.

Using interferometry and Fourier analysis, the photothermal phase map is obtained from the induced thermal lens effect in a liquid sample with high absorbance at the laser wavelength. The experimental setup consists of an adaptation of two beams thermal lens experiment, where both arms of a Sagnac's interferometer are used as probe beams. The interferograms are recorded with a CCD camera and then processed using Fourier analysis techniques. The results show that the coefficient of thermal diffusivity of a high concentrated water solution of Tartrazine is greater than that of pure water. The technique can be used to study heat transfer in opaque samples to the wavelength of the excitation beam. [ABSTRACT FROM AUTHOR]

Las barreras térmicas poseen unas propiedades mecánicas y tribológicas limitadas. Los tratamientos térmicos de sintetizado pueden utilizarse como una posible solución para su mejora. En el presente trabajo se evalúa la evolución de diversas propiedades tribológicas y mecánicas, a diferentes tiempos de sinterización, a temperatura de 1.000 °C. Se observa que el sintetizado produce un aumento de la resistencia al desgaste, de la dureza y del módulo de Young. A partir de los ensayos ball-on-disk, realizados utilizando un par friccionante de ZrO2 y de acero, se han estudiado los mecanismos de desgaste dominantes para cada uno de los pares friccionantes. Se ha observado que la delaminación entre partículas y la fractura frágil durante el proceso de desgaste son los mecanismos principales que controlan el proceso. Los caminos de desgaste estudiados mediante microscopía electrónica de barrido (SEM) e interferometría de barrido de luz blanca (SWLI) han permitido cuantificar el desgaste en cada uno de los casos. A fin de poder estudiar los recubrimientos de ZrO2 mediante SEM y SWLI ha sido necesario realizar una metalización con oro para así aumentar la conductividad eléctrica y reflectividad de las muestras.

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La tecnica interferometrica, basata sull’elaborazione coerente della fase del ritorno del segnale radar dalla superficie terrestre, ha reso il telerilevamento radar uno strumento di analisi quantitativa in molteplici campi applicativi quali cartografia, geodesia, rischio sismico, idrogeologico e vulcanico. In particolare, l’InSAR consente di produrre mappe di spostamento co-sismico, ovvero di misurare il campo di deformazione superficiale causato da un terremoto con accuratezze centimetriche. Satellite SAR interferometry for the measurement of surface deformation The SAR Interferometry (InSAR) technique is mostly used to measure the characteristics of the topography and its changes during time. The interferometric technique, based on the coherent elaboration of radar returns from the surface, has made the radar remote sensing a valuable tool for a quantitative analysis in many applicative fields such as cartography, geodesy, seismic, hydrogeologic and volcanic hazards. In particular, InSAR technique is able to measure the co-seismic surface deformation caused by an earthquake with accuracies at order of centimeters. This kind of data is extremely important for the estima-tion of the geometric parameters of the seismic source which is a relevant information for the management of event scenarios.In the last decade a new technique for the elaboration of the interferometric signal arises, the multitemporal SAR Interferometry. Thanks to the exploita-tion of a conspicuous number of SAR images, it is possible detecting and monitoring the slow soil deformation with millimetric accuracies. Moreover, the recent very high resolution satellite SAR sensors make possible to apply this technique in urban areas in order to monitor single structures such as bridges, buildings, roads and so on.

Os dados do radar imageador obtidos pela plataforma aérea R99 do Projeto SIPAM ainda esperam por validações em relação às suas precisões. Uma destas validações consiste na determinação da precisão topográfica de geração automática de RDEM (Radar Digital Elevation Model), obtido por técnica interferométrica na banda X. Nesse trabalho, a avaliação da precisão topográfica do RDEM foi feita por comparação com o DEM topográfico da área estudada, através de método de subtração. Identificou-se, primeiramente, que devido aos deslocamentos de trajetória da aeronave, o RDEM precisou ser ajustado por meio de correção planimétrica, resultando num erro RMS de 8,04 metros. O outro ajuste necessário foi a redução de uma componente de alta freqüência nos valores dos pixels que introduzia um erro adicional, o que foi conseguido por meio de filtros gauss passa baixa. Com a filtragem, o erro RMS da precisão topográfica do RDEM variou de 4,64m a 5,61m, dependendo da distância da área imageada à antena, valor que está bem próximo do erro especificado pelo fabricante, que é de 5,0 metros.

Geoportale Nazionale: the remote sensing special plan for environment Due to its geomorphological conformation, the italian territory is subject to a high hydrogeological instability. For this reason the PST-A, enacted by MATTM, is aimed at empowering the capability of land observation by collecting high resolution remote sensing data. The multitemporal database, built from Lidar and Interferometric SAR data, is available through the Geoportale Nazionale. The web portal can provide and manage geographical informations of the whole Italian country, giving organizations a tool to organize soil protection activities

Location of areas subject to hydro-geological risk using the National Geoportal and PSI data applications The availability of a database with high accuracy is a fundamental requirement of all public service are central or local government whose mission is monitoring the status of land use and management of emergencies caused by natural events and/ or anthropogenic, if it refers to the requirement that areas with high risk of disruption inevitably becomes a budget constraint and a necessary tool to support all activities of governance on land use and local coordination of emergency situations and monitoring the forecast of events.

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In this work fringes patterns axe obtain themselves experimentally that show the deformation that undergoes an object when applying to him a effort of mechanical origin, by means of digital holographic interferometry of double exposure. The experimental assembly for the digital record and the numerical reconstruction of the hologram of the object was made before and after to be deformed for, finally to obtain the deformation fringes. [ABSTRACT FROM AUTHOR]

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Es bella costumbre y hermoso hábito de cortesía el dar gracias sinceras a quienes en una ocasión y en un sitio tan respetable como ésté permiten hablar y se dignan escuchar . Yo no puedo sustraerme a tales usos sino que más bien os ruego, muy particularmente Señor Decano, señores Profesores, estimados colegas míos y señores estudiantes que os dignéis creer en el testimonio de mis agradecimientos ya que yo soy el menos autorizado para ocupar cátedra aquí y para pretender instruiros en alguna cosa.

ABSTRACT: Carajás Mineral Province, Amazon region, is the most important one in Brazil. Vale S.A. Company has the right to operate in the area of the N5E mine. The work is conducted on rock alteration products of low geomechanical quality related to sandstones, siltstones, and a lateritic cover. In order to monitor ground deformation, 33 TerraSAR-X images covering the period of March 2012-April 2013 were used in the investigation. An interferometric synthetic aperture radar (InSAR) approach based on permanent scatterer interferometry (PSI) using an interferometric point target analysis algorithm was applied. Results demonstrated that most of the area was considered stable during the time span of the image acquisition. However, persistent scatterers (PSs) with high deformation rates were mapped over a landfill probably related to settlements. To validate the PSI data, graphs were generated with the displaced information based on topographic measurements in the field. The graphs showed that the surface deformations during TSX-1 runway coverage are within the miner’s safety threshold and do not present a risk of major problems. The PSI data provided a synoptic and detailed view of the deformation process that affects the mining complex without the need of field campaign or instrumentation.

I -LA INTERFEROMETRÍA. Dr. Rafael López Ruiz, Bogotá. II-BIOGRAFÍA DE UN LIBRO. Alumno Luis Jaime Sánchez. Bogotá. III-EDITORIAL-LA LECHE Y UNO DE SUS PELIGROSOS CONTAGIOS. Dr. Alfredo Abondano Herrera. Bogotá. IV-NOTICIAS MÉDICAS. V- SECCIÓN OFICIAL. VI-BOLETÍN BIBLIOGRÁFICO