Multispectral Imaging for the Analysis of Materials and Pathologies in Civil Engineering, Constructions and Natural Spaces

Tesis por compendio de publicaciones[EN] Multispectral imaging is a non-destructive technique that combines imaging and spectroscopy to analyse the spectral behaviour of materials and land covers through the use of geospatial sensors. These sensors collect both spatial and spectral information for a given scenario and a spectral range, so that, their graphical representation elements (pixels or points) store the spectral properties of the radiation reflected by the material sample or land cover. The term multispectral imaging is commonly associated with satellite imaging, but the application range extends to other scales as close-range photogrammetry through the use of sensors on board of airborne systems (gliders, trikes, drones, etc.) or through their use at ground level. Its usefulness has been proved in a variety of disciplines from topography, geology, atmospheric science to forestry or agriculture. The present thesis is framed within close-range remote sensing applied to the civil engineering, cultural heritage and natural resources fields via multispectral image analysis. Specifically, the main goal of this research work is to study and analyse the radiometric behaviour of different natural and artificial covers by combining several sensors recording data in the visible and infrared ranges of the spectrum. The research lines have not been limited to the 2D data analysis, but in some cases 3D intensity data have been integrated with 2D data from active (terrestrial laser scanners) and passive (multispectral digital cameras) sensors in order to analyse different materials and possible associated pathologies, getting more comprehensive products due to the metric that 3D brings to 2D data. Works began with the radiometric calibration of the active and passive sensors used by the vicarious calibration method. The calibrations were carried out through MULRACS, a multispectral radiometric calibration software developed for this purpose (see Appendix B). After the calibration process, active and passive sensors were used together for the discretization of sedimentary rocks and detecting pathologies, as moisture, in façades and in civil structures. Finally, the Doctoral Thesis concludes with a theoretical book chapter in which all the know-how and expertise arising during this research stage have been compiled.[ES]Las imágenes multiespectrales se constituyen como técnica no destructiva que combina imagen y espectroscopía para analizar el comportamiento espectral de distintos materiales y superficies terrestres a través del uso de sensores geoespaciales. Estos sensores adquieren tanto información espacial como espectral para un escenario y un rango espectral dados de tal forma sus unidades de representación gráfica (ya sean píxeles o puntos) registran las propiedades de la radiación reflejada para cada material o cobertura a estudiar y longitud de onda. Las imágenes multiespectrales no solo se limitan a las observaciones satelitales a las que tradicionalmente se vinculan, sino que tienen un campo de aplicación más amplio gracias a los estudios de rango cercano realizados a través del uso de sensores tanto embarcados en sistemas aéreos (planeadores, paramotores, drones, etc.) como a nivel terreno. Su utilidad ha sido demostrada en multitud de disciplinas; desde la topografía, geología, aerología, hasta la ingeniería forestal o la agricultura entre otros. La presente tesis se enmarca dentro de la teledetección de rango cercano aplicada a la ingeniería civil, el patrimonio cultural y los recursos naturales a través del análisis multiespectral de imágenes. Concretamente, el principal objetivo de este trabajo de investigación consiste en el estudio y análisis del comportamiento radiométrico de distintas coberturas naturales y artificiales mediante el uso combinado de distintos sensores que registran información espectral en los rangos visible e infrarrojo del espectro electromagnético. Las líneas de investigación no se han limitado al análisis de datos bidimensionales (imágenes) sino que en algunos casos se han integrado datos de intensidad registrados en 3D a través de sensores activos (láser escáner terrestres) con datos 2D capturados con sensores pasivos (cámaras digitales convencionales y multiespectrales) con el objetivo de analizar diferentes materiales y posibles patologías asociadas a los mismos ofreciendo resultados más completos gracias a la métrica que los datos 3D aportan a los datos 2D. Los trabajos comenzaron con la calibración radiométrica de los sensores por el método de calibración vicario. Las calibraciones fueron resueltas gracias al uso del software MULRACS, un software para la calibración radiométrica multiespectral desarrollado durante este periodo para tal fin (ver Apéndice B). Tras el proceso de calibración, se combinó el uso de sensores activos y pasivos para la diferenciación de distintos tipos de rocas sedimentarias y la detección de patologías, como humedades, en fachadas de edificios históricos y en estructuras de ingeniería civil. Finalmente, la Tesis Doctoral concluye con un capítulo teórico de libro en el cual se recopilan todos los conocimientos y experiencias adquiridos durante este periodo de investigación

Experimental study on the thermal properties of pigmented mortars for use in energy efficiency applications

[EN] This study aims at investigating the application of pigments on mortars and evaluating how it affects their thermal properties. In addition, it was analysed whether the addition of this type of substance affects the mechanical and optical properties of the mortars. For this purpose, several mortar samples were made with grey and white cement to which different concentrations of black and white pigment were added. The mechanical characterization tests showed that the compressive strength is not affected by the addition of pigments in the proportions supplied. On the other hand, the thermal conductivity tests also showed a negligible relationship between the proportion of pigment added and the change in the mortar conductivity. Then, the thermal behaviour of these mortar samples subjected to heating with a low-cost solar simulator was also monitored. Results revealed a significant increase in temperature for the mortar samples with black pigments, while those with white pigments barely reduced this temperature. Finally, after performing a spectral reflectance test, a correlation was found between the reflectivity of the pigmented mortars in the optical spectrum and their thermal behaviour.SIThe authors want to thank the Spanish Ministry of Education, Culture and Sports for providing an FPU grant (Training Program for Academic Staff) to the corresponding author of this paper (grant number FPU20/01376 ). This work was financed by ERDF funds and Junta of Castilla y León through the TCUE 2021–2023 program within the framework of the DACHARAP project ( N° Ref. PC-TCUE21-23_033 )

Comparing Terrestrial Laser Scanning (TLS) and Wearable Laser Scanning (WLS) for Individual Tree Modeling at Plot Level

54 p.This study presents a comparison between the use of wearable laser scanning (WLS) and terrestrial laser scanning (TLS) devices for automatic tree detection with an estimation of two dendrometric variables: diameter at breast height (DBH) and total tree height (TH). Operative processes for data collection and automatic forest inventory are described in detail. The approach used is based on the clustering of points belonging to each individual tree, the isolation of the trunks, the iterative fitting of circles for the DBH calculation and the computation of the TH of each tree. TLS and WLS point clouds were compared by the statistical analysis of both estimated forest dendrometric parameters and the possible presence of bias. Results show that the apparent differences in point density and relative precision between both 3D forest models do not affect tree detection and DBH estimation. Nevertheless, tree height estimation using WLS appears to be affected by the limited scanning range of the WLS used in this study. TH estimations for trees below a certain height are equivalent using WLS or TLS, whereas TH of taller trees is clearly underestimated using WLSS

Ener3DMap-SolarWeb roofs: A geospatial web-based platform to compute photovoltaic potential

[EN] The effective exploitation and management of renewable energies requires knowledge not only of the energy intensity at the exploitation site but also of the influence of the geometry of the site and its surroundings. For this reason, the efficient processing and interpretation of combined geospatial and energy data is a key issue. This paper presents the development of a web-based tool for the automatic computation of photovoltaic potential on rooftops and on parcels without buildings. The tool called Ener3DMap-SolarWeb Roofs is based on Leaflet and supports WMS, GeoJSON, GeoCSV and KML formats, among others. With these data formats, base maps, geometric data from the rooftops automatically computed from LiDAR and imagery data with self-developed processing algorithms, cadastral data and a solar radiation model are integrated in the tool. These different types of data, the high level of automation and the different scales for which energy data is calculated (hourly, monthly and annually) are the main contributions of the presented tool compared to other existing solutions. The capacities of the tool are tested through its application to analyze the solar potential of rooftops with different shapes and for different solar panel configurations. The accuracy of the results is ensured through the integration of a validated methodology for the computation of geometry and a validated solar radiation model, PVGIS

Heritage site preservation with combined radiometric and geometric analysis of TLS data

Damage mapping is considered a critical stage in the correct diagnosis of the state of conservation of Cultural Heritage manifestations. The common approach generally implies a large user interaction to map the different pathological processes presented on 2D documents such as elevations or sections, among others. In contrast with this practice, the present paper proposes a semiautomatic 3D-methodology, with a minimum user interaction, able to accurately analyse both radiometric and geometric data recovered by a non-contact technology (Terrestrial Laser Scanning), allowing the extraction and quantification of a wide diversity of pathological processes from biological colonization to deformations. This approach is therefore a potential tool for the rapid and accurate diagnosis of Cultural Heritage. To confirm the applicability and potential offered by the proposed methodology, a highly affected historical masonry, the San Francisco Master Gate of the Almeida Fortress (Portugal), was evaluated by using the Faro Focus 3D 120 Laser Scanner

Novel Pole Photogrammetric System for Low-Cost Documentation of Archaeological Sites: The Case Study of “Cueva Pintada”

19 p.Close-range photogrammetry is a powerful and widely used technique for 3D reconstruction of archaeological environments, specifically when a high-level detail is required. This paper presents an innovative low-cost system that allows high quality and detailed reconstructions of indoor complex scenarios with unfavorable lighting conditions by means of close-range nadir and oblique images as an alternative to drone acquisitions for those places where the use of drones is limited or discouraged: (i) indoor scenarios in which both loss of GNSS signal and need of long exposure times occur, (ii) scenarios with risk of raising dust in suspension due to the proximity to the ground and (iii) complex scenarios with variability in the presence of nooks and vertical elements of different heights. The low-altitude aerial view reached with this system allows high-quality 3D documentation of complex scenarios helped by its ergonomic design, self-stability, lightness, and flexibility of handling. In addition, its interchangeable and remote-control support allows to board different sensors and perform both acquisitions that follow the ideal photogrammetric epipolar geometry but also acquisitions with geometry variations that favor a more complete and reliable reconstruction by avoiding occlusions. This versatile pole photogrammetry system has been successfully used to 3D reconstruct and document the “Cueva Pintada” archaeological site located in Gran Canaria (Spain), of approximately 5400 m2 with a Canon EOS 5D MARK II SLR digital camera. As final products: (i) a great quality photorealistic 3D model of 1.47 mm resolution and ±8.4 mm accuracy, (ii) detailed orthophotos of the main assets of the archaeological remains and (iii) a visor 3D with associated information on the structures, materials and plans of the site were obtained.S

Adaptar la web con "Mobile First" y mejora del posicionamiento SEO para el Máster en Geotecnologías Cartográficas en Ingeniería y Arquitectura

Memoria ID-037. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2018-2019

Prevalence of MITF p.E318K in patients with melanoma independent of the presence of CDKN2A causative mutations

Importance The main high-penetrance melanoma susceptibility gene is CDKN2A, encoding p16INK4A and p14ARF. The gene MITF variant p.E318K also predisposes to melanoma and renal cell carcinoma. To date, the prevalence of MITF p.E318K and its clinical and phenotypical implications has not been previously assessed in a single cohort of Spanish patients with melanoma or in p16INK4A mutation carriers.Objectives To evaluate the prevalence of MITF p.E318K in Spanish patients with melanoma and assess the association with clinical and phenotypic features.Design, Setting, and Participants A hospital-based, case-control study was conducted at the Melanoma Unit of Hospital Clinic of Barcelona, with MITF p.E318K genotyped in all patients using TaqMan probes. We included 531 patients: 271 patients with multiple primary melanoma (MPM) without mutations affecting p16INK4A (wild-type p16INK4A); 191 probands from melanoma-prone families with a single melanoma diagnosis and without mutations affecting p16INK4A, and 69 probands from different families carrying CDKN2A mutations affecting p16INK4A. A population-based series of 499 age- and sex-matched cancer-free individuals from the Spanish National Bank of DNA were included as controls. Patients were recruited between January 1, 1992, and June 30, 2014; data analysis was conducted from September 1 to November 30, 2014.Main Outcomes and Measures The genetic results of the MITF p.E318K variant were correlated with clinical and phenotypic features.Results Among the 531 patients, the prevalence of the MITF p.E318K variant was calculated among the different subsets of patients included and was 1.9% (9 of 462) in all melanoma patients with wild-type p16INK4A, 2.6% (7 of 271) in those with MPM, and 2.9% (2 of 69) in the probands of families with p16INK4A mutations. With results reported as odds ratio (95% CI), the MITF p.E318K was associated with an increased melanoma risk (3.3 [1.43-7.43]; P 200 nevi) (8.4 [2.14-33.19]; P < .01). Two fast-growing melanomas were detected among 2 MITF p.E318K carriers during dermatologic digital follow-up.Conclusions and Relevance In addition to melanoma risk, MITF p.E318K is associated with a high nevi count and could play a role in fast-growing melanomas. Testing for MITF p.E318K should not exclude patients with known mutations in p16INK4A. Strict dermatologic surveillance, periodic self-examination, and renal cell carcinoma surveillance should be encouraged in this context

Hyperspectral imaging and robust statistics in non-melanoma skin cancer analysis

Non-Melanoma skin cancer is one of the most frequent types of cancer. Early detection is encouraged so as to ensure the best treatment, Hyperspectral imaging is a promising technique for non-invasive inspection of skin lesions, however, the optimal wavelengths for these purposes are yet to be conclusively determined. A visible-near infrared hyperspectral camera with an ad-hoc built platform was used for image acquisition in the present study. Robust statistical techniques were used to conclude an optimal range between 573.45 and 779.88 nm to distinguish between healthy and non-healthy skin. Wavelengths between 429.16 and 520.17 nm were additionally found to be optimal for the differentiation between cancer types.Gerencia Regional de Salud de Castilla y León (GRS 2139/A/20); Spanish Ministry of Science, Innovation and Universities (PRE2019-089411); Instituto de Salud Carlos III (PI18/00587); Ibderdrola Spain; Junta de Castilla y León (GRS 1837/A/18). This project was funded by the Junta de Castilla y Leon, under the title project HYPERSKINCARE (Ref. GRS 1837/A/18). Lloyd Austin Courtenay is funded by the Spanish Ministry of Science, Innovation and Universities with an FPI Predoctoral Grant (Ref. PRE2019-089411) associated to project RTI2018-099850-B-I00 and the University of Salamanca. Susana Lagüela and Susana del Pozo are both funded by the Iberdrola Spain through the initiative Cátedra Iberdrola VIII Centenario of the University of Salamanca. Javier Cañueto is partially supported by the PI18/00587(Instituto de Salud Carlos III cofinanciado con fondos FEDER) and GRS 2139/A/20 (Gerencia Regional de Salud de Castilla y León

Deep Convolutional Neural Support Vector Machines for the Classification of Basal Cell Carcinoma Hyperspectral Signatures

[EN] Non-melanoma skin cancer, and basal cell carcinoma in particular, is one of the most common types of cancer. Although this type of malignancy has lower metastatic rates than other types of skin cancer, its locally destructive nature and the advantages of its timely treatment make early detection vital. The combination of multispectral imaging and artificial intelligence has arisen as a powerful tool for the detection and classification of skin cancer in a non-invasive manner. The present study uses hyperspectral images to discern between healthy and basal cell carcinoma hyperspectral signatures. Upon the combined use of convolutional neural networks, with a final support vector machine activation layer, the present study reaches up to 90% accuracy, with an area under the receiver operating characteristic curve being calculated at 0.9 as well. While the results are promising, future research should build upon a dataset with a larger number of patients.SIJunta de Castilla y Leo