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In the geomatics field, modelling and georeferencing complex speleological structures are some of the most challenging issues. The use of conventional survey methods (for example, those employing total stations or terrestrial laser scanner) becomes more difficult, especially because of the space constraints and the often critical light conditions. In this work, a flexible and swift methodology to survey an in-progress excavation is presented, through image-based modelling techniques. The proposed approach allows obtaining a reliable and georeferenced three-dimensional model of the underground environments, preserving the integrity of the scene. The 3D model is scaled and georeferenced through three ground control points located just outside the cave, using data acquired by a double-frequency GNSS receiver in static session mode. Further targets were employed to check the deformation of the model inside the cave. The surveys were conducted on two archaeological sites: La Sassa cave and Guattari cave, both located in southern Latium.

MSc (Geografie en Omgewingsbestuur), North-West University, Potchefstroom Campus Rock art data is currently made available digitally by means of diverse databases, equipped with limited research capabilities. The global distribution of rock art complicates its research and forces researchers to rely on its online availability. Should some of the elements in such an artwork appear to be unclear, online applications that could lead to the possible enhancement of it must be sought on an individual basis. This study seeks to meet this need by creating and making available an online data model containing rock art that provides the consumer with built-in distance analysis software tools related to the data. Petroglyphs of Bosworth rock art site have been documented and presented for this purpose in context of their immediate surroundings, namely the rocks and site concerned. To make this data available online, a web application has been created with built-in analytics capabilities in terms of magnification, manipulation of the viewing angle, allocation of new colour spaces, as well as the casting of a digital light beam over the artworks. A combination of these built-in analysis functionalities is then available for application to both 2D and 3D depictions of each artwork in colour as well as monochrome. Masters

[EN] This communication presents the formulation and first steps of an Industrial PhD project, developed in the frame of the “Kuk ahpán” project (Spanish National R&D Plan, 2019-2022) that aims to understand, monitor and model tectonic processes at the lithospheric scale in Central America. For this purpose, an international team from six countries (Nicaragua, Costa Rica, El Salvador, Guatemala, Norway and Spain) works integrating research in diverse geophysical techniques and engineering, with the aim of updating Seismic Risk Maps for the Region, a critical input for Safety and Construction Codes. The proposed PhD project is framed on the research and development of technologies to prevent natural and induced geological risks that affect cities and infrastructures in highly vulnerable countries, using the DInSAR (Differential Interferometry with Synthetic Aperture Radar) technology optimized by the startup Detektia Earth Surface Monitoring in collaboration with Universidad Politécnica de Madrid. Differential Synthetic Aperture Radar Interferometry is a technique based on the processing and analysis of long series of Synthetic Aperture Radar images. This technology provides records (since 1992) and up-to-date movements on any surface anywhere in the world without the need for ground instrumentation, with accuracies about 1 mm/year (velocity). In this context satellite radar provides valuable information on very large areas that complement the field work and in-situ instrumentation. The methodological approach starts by integrating DInSAR data with geophysical and geodesical data such as bathymetry, geomagnetism, gravimetry, seismic profiles, GNSS series… to fully map the Swan fault over Honduras and Guatemala. We use this technology to address the seismic risk over the fault and nearby areas. Then, on a second step, we will apply this seismic risk assessment (including natural and anthropogenic hazards) in prioritized cities and critical infrastructures in Central America., [ES] Este documento presenta la formulación y primeros pasos de un proyecto de Doctorado Industrial, desarrollado en el marco del proyecto Kuk ahpán que tiene como objetivo comprender, monitorear y modelar procesos tectónicos a escala litosférica en Centroamérica. Para ello, un equipo internacional de seis países (Nicaragua, Costa Rica, El Salvador, Guatemala, Noruega y España) trabaja integrando la investigación en diversas técnicas e ingenierías Geofísicas, con el objetivo de actualizar los Mapas de Riesgo Sísmico de la Región, un insumo crítico. para los códigos de seguridad y construcción. El proyecto de doctorado propuesto se enmarca en la investigación y desarrollo de tecnologías para prevenirlos riesgos geológicos naturales e inducidos que afectan a ciudades e infraestructuras en países altamente vulnerables, utilizando la tecnología DInSAR (Differential Interferometry with Synthetic Aperture Radar) optimizada por la startup Detektia Earth Surface Monitoring en colaboración con la Universidad Politécnica de Madrid. La interferometría diferencial de radar de apertura sintética es una técnica basada en el procesamiento y análisis de series largas de imágenes de radar de apertura sintética. Esta tecnología proporciona registros (desde 1992) y movimientos actualizados en cualquier superficie en cualquier parte del mundo sin necesidad de instrumentación terrestre, con precisiones de alrededor de 1 mm/ año (velocidad). En este contexto, el radar satelital proporciona información valiosa sobre áreas muy grandes que complementan el trabajo de campo y la instrumentación in situ. Primero, comenzamos integrando datos DInSAR con diversos datos geofísicos como batimetría, geomagnetismo, gravimetría, perfiles sísmicos… para mapear completamente la falla Swan sobre Honduras y Guatemala. Usamos esta tecnología para abordar el riesgo sísmico sobre la falla y áreas cercanas. En un segundo paso, aplicaremos esta evaluación de riesgo sísmico (incluyendo amenazas naturales y antropogénicas) en ciudades e infraestructuras críticas en Centroamérica., Esta línea de investigación ha sido desarrollada con el apoyo de los equipos de Detektia Earth Surface Monitoring SL, la E.T.S.I. de Caminos, Canales y Puertos de la Universidad Politécnica de Madrid y el equipo de trabajo de Kuk ahpán.

[EN] The frequency and intensity of extreme worldwide weather events have increased in recent decades, causing enormous economic losses. In Argentina, in the 2017-2018 agricultural season, more than 200 million dollars were allocated to protect soy, corn and wheat crops against hail. After a storm, a field survey by an expert is required to estimate the yield losses caused by hail, without prior information on the affected regions or their intensity. The precision in the estimation of the damage depends to a great extent on the identification of Homogeneous Damage Zones (HDZ) within the plot, which is further used to quantify the total damage. Currently, HDZ are delimited using in-situ visual techniques. This research suggests developing an algorithm to define the HDZ applying Machine Learning techniques to vegetation indices derived from Sentinel 1 and 2 data. For this purpose, 5 microwave indices (DPDD, IDPDD, VDDPI, MPDI and DPSVI) and 5 spectral indices (NDVI, EVI, SAVI, AVI and NPCRI) were tested. The most sensitive indices to changes were selected, for both microwave and optical signals, and were in turn integrated into the damage detection model. A K-Means (k = 3) machine learning algorithm was used to define the classes. To validate the algorithm, 38 storms that occurred between 2017 and 2020 were analyzed in 91 soybean, wheat and corn plots located in the Argentine Pampean plain. The One-Way ANOVA model (p, [ES] La frecuencia e intensidad de los eventos meteorológicos extremos, a nivel mundial, se han incrementado en las últimas décadas, provocando enormes pérdidas económicas. En Argentina, en la campaña agrícola 2017-2018, se destinaron más de 200 millones de dólares para proteger los cultivos soja, maíz y trigo contra granizo. Luego de una tormenta, un perito visita el campo para estimar las mermas de rendimiento causadas por granizo, sin información previa de las regiones afectadas ni su intensidad. La precisión en la estimación del daño depende en gran medida de la identificación de Zonas Homogéneas de Daños (ZHD) dentro de la parcela para ponderar el daño total. Actualmente, las ZHD se delimitan acampo con técnicas visuales. Se propone desarrollar un algoritmo para definir las ZHD aplicando técnicas Machine Learning a índices de vegetación calculados con datos Sentinel 1 y 2. Se procesaron y compararon 5 índices de microondas (DPDD, IDPDD, VDDPI, MPDI y DPSVI) y 5 espectrales (NDVI, EVI, SAVI, AVI y NPCRI) y se seleccionó el más sensible a los cambios para cada tipo de señal; además, se incorporaron como variable de entrada al modelo las derivadas de ambos índices. Para definir las clases se empleó K-Means (k = 3). Para validar el algoritmo se analizaron38 tormentas ocurridas entre los años 2017 y 2020 en 91 parcelas de soja, trigo y maíz ubicadas en la llanura pampeana argentina. Se aplicó a cada parcela el modelo One-Way ANOVA (p

An example of the combined use of UAV photogrammetry and rockfall numerical simulation is described. A case of fragmental rockfall occurred on 17 November 2018 in Cárcavos, a site located in the Spanish municipality of Ayna (Albacete). The event caused a great social alarm as some infrastructure was affected. By using Unmanned Aerial Vehicle (UAV) photogrammetry, a high-resolution 3D model has been generated from point cloud data, and distribution and size of the fragmented rocks (more than 600 boulders) determined. The analysis has been performed through numerical simulations to: (1) reproduce the paths followed by the real blocks; and (2) estimate the speed and energy of the blocks, together with their heights, impacts and stopping points. Accordingly, source areas have been identified, including the potential source areas and unstable blocks on the slope. In addition, the exposed elements at risk (buildings, facilities, infrastructures, etc.) have been identified, and the effectiveness of mitigation measures against future events evaluated.

[EN] Environmental degradation or contamination is subject to the presence of heavy metals such as: arsenic, cadmium, mercury, nickel, lead, etc., which may have a geogenic (natural) or anthropogenic origin (produced by hazardous waste), the latter bring with them negative consequences for human health, due to the bioaccumulation of trace elements. Today, spectrometric techniques, through the integration of geospatial technologies and multi-source data, are considered an alternative to traditional field sampling methods, and their use is gaining strength every day. This article uses the so-called “Crosta technique” to detect the presence of characteristic minerals existing in the Southeast Regional Park of the Autonomous Community of Madrid, and, on the other hand, to locate the existence of heavy metals. In a qualitative evaluation, applying the “Crosta composition”, a high concordance between the minerals bentonite and sepiolite is evidenced with the official contrast cartography, from the Geological and Mining Institute of Spain, in addition, a slight modification was made in the input bands of the “Crosta composition”, obtaining an overestimation of the minerals. Finally, by means of a visual interpretation of those main components that contain the spectral information related to heavy metals, a list of coordinates was generated, which will be validated in field campaigns, where the use of spectroradiometers and the chemical analysis of samples will be key to determine the goodness of the results., [ES] La degradación o contaminación ambiental se encuentra sujeta a la presencia de metales pesados como: arsénico, cadmio, mercurio, níquel, plomo, etc., los cuales pueden tener origen geogénico (natural) o antropogénico (producidospor residuos peligrosos), estos últimos, traen consigo consecuencias negativas para la salud humana, debido a la bioacumulación de elementos traza. Hoy en día, las técnicas espectrométricas, mediante la integración de tecnologías geoespaciales y datos multifuente, son consideradas como una alternativa a los métodos tradicionales de muestreo decampo, y su empleo cada día cobra más fuerza. El presente artículo, emplea la denominada “técnica de Crosta” para detectar la presencia de minerales característicos existentes en el Parque Regional del Sureste de la Comunidad Autónoma de Madrid, y, por otro lado, para localizar la existencia de metales pesados. De manera cualitativa, aplicandola “composición Crosta”, se evidencia una alta concordancia entre los minerales bentonita y sepiolita con la cartografía oficial de contraste, procedente del Instituto Geológico y Minero de España, además, se realizó una leve modificación en las bandas de entrada de la “composición Crosta”, obteniendo una sobre estimación de los minerales. Por último, mediante una interpretación visual de aquellas componentes principales que contienen la información espectral relativa a metales pesados, se generó un listado de coordenadas, las cuales serán validadas en campañas de campo, en donde el uso de espectroradiómetros y el análisis químico de muestras serán claves para determinar la bondad de los resultados., La presente investigación tiene el apoyo de: Secretaría de Educación Superior, Ciencia, Tecnología e Innovación (SENESCYT), mediante la beca otorgada dentro del marco de la convocatoria abierta 2017 - componente general. Instituto Geográfico Militar del Ecuador (IGM), mediante la concesión del permiso respectivo para poder efectuar estudios regulares de posgrado en España. Tepro Consultores Agrícolas SL, mediante las prácticas doctorales realizadas a partir del 01/03/2021 hasta la actualidad.

[EN] In recent years, the production of panoramic images has been boosted by the increasing use of digital photographiccameras and mobile phones. However, for highly demanding applications such as long-range deformation monitoring, theaccuracy and quality control of panoramic images and processes used to obtain accurate 3D models should be properlyassessed. Therefore, prior to being applied in real projects, the quality of the spherical panoramic images generated bythree widely used computer programs (Agisoft Metashape, GigaPan Stitch and PTGui) is evaluated using the same imagesof a photogrammetric laboratory full of control points and an outdoor environment by shooting from several stations. Inaddition to the assessment of the geometrical accuracy, the study also includes important aspects for practical efficiencysuch as workflow, speed of processing, user-friendliness, or exporting products and formats available. The results of thecomparisons show that Agisoft Metashape meets the required geometric specifications with higher quality and has clearadvantages in performance if compared to the other two tested programs., [ES] En los últimos años, la producción de imágenes panorámicas se ha visto impulsada por el uso cada vez mayor de cámaras fotográficas digitales y teléfonos móviles. Sin embargo, deben evaluarse adecuadamente en aplicaciones altamente exigentes como la monitorización de deformaciones a grandes distancias, la precisión y el control de calidad de las imágenes panorámicas y los procesos utilizados para obtener modelos 3D precisos. Por consiguiente, antes de ser aplicadas en proyectos reales, se evalúa la calidad de las imágenes panorámicas esféricas generadas por tres programas informáticos ampliamente utilizados (Agisoft Metashape, GigaPan Stitch y PTGui) utilizando las mismas imágenes de un laboratorio fotogramétrico lleno de puntos de apoyo y del exterior desde varias estaciones. Además de la evaluación de la precisión geométrica, el estudio también incluye aspectos importantes para la eficiencia práctica como es el flujo de trabajo, la velocidad de procesamiento, la facilidad de uso o la exportación de productos y los formatos disponibles. Los resultados de las comparaciones muestran que Agisoft Metashape cumple con las especificaciones geométricas requeridas con mayor calidad y tiene claras ventajas de rendimiento si se compara con los otros dos programas testeados.

[EN] Due to their oceanographic and climatic ecological characteristics, the coastal areas of the Valparaíso Region of Chile are of great importance for the country's tourist, economic, and environmental development. The region's coasts have been affected by extreme events since 2015, with recurrent swells that have increased between 10% and 25% compared to previous years, causing the interruption of the annual dynamic process of the beaches accentuated by anthropic interventions on beaches, wetlands and coastal dunes that promote coastal degradation. This work aims to characterize which part of the beaches and at what time of year there is a higher risk of severe erosion in the immediate areas to the coast and explain its causes based on satellite images of medium resolution satellite images. 128 SDS were extracted with Landsat 8 OLI and Sentinel 2 images with systems SHOREX. Average widths calculated for the series in each of the seasons. Recording the minimum widths in the proximal areas with averages of 12.3 m; 23.6 m and 21.2 m Concón Bay, Reñaca Beach and Algarrobo bay, respectively showing critical or problematic states. The dominant direction of the waves and the geographical disposition of the three beaches seems evident that there is a robust longitudinal transport to the north that generates less sediment accumulation in the proximal areas. The seasonal variation of the beaches distinguishes by more energetic conditions in winter than in summer. But they are also influenced by rapid episodic periods, low atmospheric pressure systems from the north and south, swells and tropical storms. Hence, it is unlikely that the variations in the width of the beach are only due to winter-summer energetic conditions., [ES] Las áreas costeras de la región de Valparaíso de Chile por sus características oceanográficas, climáticas y ecológicas son de gran importancia para el desarrollo turístico, económico y ambiental del país. Las costas de la región se han visto afectadas por eventos extremos desde 2015, con marejadas recurrentes que han aumentado respecto a años anteriores entre el 10% y 25%. Esto ha provocado la interrupción del proceso dinámico anual de las playas, acentuado por las intervenciones antrópicas sobre estos ambientes costeros, humedales y dunas que promueven su degradación. El trabajo que se presenta tiene como objetivo caracterizar en qué parte de las playas y en qué momento del año hay un riesgo más alto de erosión grave en las áreas inmediatas a la costa, así como tratar de explicar sus causas apoyándose en la utilización de imágenes satelitales de resolución media. Se extrajeron 128 SDS con imágenes Landsat 8 OLI y Sentinel 2 con el sistema SHOREX. Se calcularon los valores promedio de anchura de playa para la serie en cada una de las temporadas registrando anchuras mínimas en las zonas proximales de 12,3 m; 23,6 m y 21,2 m para la Bahía de Concón, Playa Reñaca y Bahía de Algarrobo respectivamente, demostrando estados críticos o problemáticos. La dirección dominante del oleaje y la disposición geográfica de las tres playas hace evidente la existencia de un fuerte transporte longitudinal hacia el norte que genera que las áreas proximales presenten menor acumulación de sedimentos. La variación estacional de las playas se caracteriza por condiciones más energéticas en invierno que en verano. No obstante, se ven también influenciadas por periodos episódicos rápidos, sistemas de bajas presiones atmosféricas del norte y del sur, así como marejadas y tormentas tropicales que se suman al moldeamiento de las playas., Este trabajo ha sido financiado por la Agencia Nacional de Investigación y Desarrollo (ANID) a través del FONDEF IDeA I+D 2019 – Desafío País Adaptación al Cambio Climático y Desastres Naturales. Código Proyecto ID19I10361. Agradecimiento a los practicantes de Escuela de Geología de la Universidad Mayor por su colaboración en la toma de datos en campo y procesamiento de datos sedimentarios. Álvaro Millamán, Maximiliano Parrao, Catalina Cerda, Nicolás Rodríguez, a las asistentes, Natalia Medina, Roxana Mansilla. Al IHC Cantabria que nos ha cedido datos de oleaje y marea de la zona.

[EN] The use of medium/high-density LIDAR (Light Detection And Ranging) data for land modelling and DTM (Digital Terrain Model) is becoming more widespread. This level of detail is difficult to achieve with other means or materials. However, the horizontal and vertical geometric accuracy of the LIDAR points obtained, although high, is not homogeneous. Horizontally you can reach precisions around 30-50 cm, while the vertical precision is rarely greater than 10-15 cm. The result of LIDAR flights, are clouds of points very close to each other (30-60 cm) with significant elevation variations, even if the terrain is flat. And this makes the triangulated models TIN (Triangulated Irregular Network) obtained from such LIDAR data especially chaotic. Since contour lines are generated directly from such triangulated models, their appearance shows excessive noise, with excessively broken and rapidly closed on themselves. Getting smoothed contour liness, without decreasing accuracy, is a challenge for terrain model software. In addition, triangulated models obtained from LIDAR data are the basis for future slope maps of the land. And for the same reason explained in the previous paragraph, these slope maps generated from high or medium density LIDAR point clouds are especially heterogeneous. Achieving uniformity and greater adjustment to reality by reducing the natural noise of LIDAR data is another added challenge. In this paper, the problem of excessive noise from LIDAR data of high (around 8 points/m2) and medium density (around 2 points/m2) in the generation of contour lines and terrain slope maps is raised and solutions are proposed to reduce this noise. All this, in the area of specific software for the management of TIN models and GIS (Geographic Information System) and adapting the alternatives proposed by these programmes., [ES] El uso de datos LIDAR de alta densidad para la modelización del terreno y obtención de MDT (Modelo Digital del Terreno) está cada día más generalizado. El nivel de detalle conseguido es difícil de alcanzar con otros medios o materiales. No obstante, la precisión geométrica horizontal y vertical de los puntos LIDAR obtenidos, aunque es alta, no es homogénea. Horizontalmente se puede llegar a precisiones del orden de los 30-50 cm, mientras la precisión vertical raras veces es mayor de 10-15 cm. El resultado de los vuelos LIDAR, son nubes de puntos muy próximos entre sí (30-60 cm) con variaciones de cota importantes, aunque el terreno sea llano. Y esto hace que los modelos triangulados TIN (Triangulated Irregular Network) obtenidos a partir de dichos datos LIDAR sean especialmente caóticos. Dado que las curvas de nivel se generan directamente a partir de dichos modelos triangulados, su apariencia muestra excesivo ruido, con curvas excesivamente quebradas y rápidamente cerradas sobre sí mismas. Conseguir curvas suavizadas, sin disminuir la precisión, es un reto para los programas de modelización de terrenos. Además, los modelos triangulados obtenidos a partir de datos LIDAR, son la base de los futuros mapas de pendiente de los terrenos. Y por la misma razón explicada en el párrafo anterior, estos mapas de pendiente generados a partir de nubes de puntos LIDAR de alta o media densidad, son especialmente heterogéneos. Conseguir uniformidad y mayor ajuste a la realidad reduciendo el ruido natural de los datos LIDAR es otro reto añadido. En esta comunicación, se plantea la problemática del excesivo ruido de los datos LIDAR de alta (en torno a 8 puntos/m2) y media densidad (en torno a 2 puntos/m2) en la generación de curvas de nivel y mapas de pendiente del terreno y se proponen soluciones para reducir dicho ruido. Todo ello, en el ámbito de programas específicos de gestión de modelos TIN y de los SIG (Sistemas de Información Geográfica) y adaptando las alternativas que dichos programas plantean., Our gratitude to the National Geographic Institute and the Government of La Rioja, for making available to us in a totally disinterested way sheets of the LIDAR PNOA 2016 flight produced within the framework of the National Cartographic System (SCNE).

[EN] The cultivation of tomato solanum lycopersicum is of great economic importance in Colombia, being Cundinamarca the fifth producing department of the country with an average of 371,827 tons for the year 2019. New emerging technologies such as precision agriculture applied to the agricultural sector represent an opportunity to monitor physiological processes. Through the application of Remote Sensing with aerial images taken by UAV unmanned aerial vehicles and time series calculations of plant indices such as the Green Chlorophyll Index (GCI), information on the production potential of the crop was quantified. The objective of this research was to extract relevant information from the production process in the batches, using Geomatic techniques. As results, the main batches with the highest production were identified, based on photosynthetic activity and growth height using a digital surface model, generated from the information obtained by photogrammetric flights. It was also possible to identify some microclimates generated in the lots, as a consequence of the difference in height found in the study area. As a final conclusion of achievement, obtain information and current characteristics of the plantation in order to make decisions in the next plantings., [ES] El cultivo de tomate solanum lycopersicum es de gran importancia económica en Colombia, siendo Cundinamarca el quinto departamento productor del país con un promedio de 371.827 toneladas para el año 2019. Las nuevas tecnologías emergentes como la agricultura de precisión aplicada al sector agrícola, representan una oportunidad para monitorear procesos fisiológicos. Mediante la aplicación de la teledetección con imágenes aéreas tomadas por vehículos aéreos no tripulados UAV y cálculos de series de tiempo de índices vegetales como el Green Chlorophyll Index (GCI), se cuantificó información sobre el potencial de producción del cultivo. El objetivo de la presente investigación fue extraer información relevante del proceso productivo en los lotes, mediante técnicas geomáticas. Como resultados se identificaron los principales lotes con mayor producción, basados en la actividad fotosintética y la altura de crecimiento utilizando un modelo digital de superficie, generado partir de la información obtenida por los vuelos fotogramétricos. También se pudo identificar algunos microclimas generados en los lotes, como consecuencia de la diferencia de altura encontrada en la zona de estudio. Como conclusión final se logró obtener información y características actuales de la plantación con el finde tomar decisiones en las próximas siembras., Se agradece al grupo de investigación geocartografia, y al proyecto de investigación “Herramienta geoespacial para la construcción del diagnóstico socioambiental del Plan de Desarrollo Territorial del municipio de Silvania - Cundinamarca.”, código 63546, convocatoria Colciencias 2018.

[EN] In recent years, Remote Sensing (RS) and its derived products have been used as a key tool for the detection, monitoring, management and future use of Marginal Lands (ML). Currently, there is no single, universally accepted definition of the term and there is a wide variety of synonyms. In this paper, we conduct a compilation of synonyms and meanings that encompass the term, as well as propose a definition. To reach this objective, an overview of the state of the art of ML is done, visualising trends by science maps, based on bibliographic data of established research journals, found in Google Scholar, Web of Science (WoS) and Scopus search engines. The bibliographic review carried out shows that the study of ML has traditionally been carried out with an ad hoc basis focused on the objective to be achieved, this aspect and other knowledge gaps are discussed to analyse the global study of ML. Due to the broad spectrum of uses in which ML have been studied, the work has been focused on RS for monitoring and characterizing ML, focusing on two different aspects: (i) satellite monitoring of marginal lands; and (ii) determining carbon sequestration potential of marginal lands using remote sensing., [ES] En los últimos años, la teledetección y sus productos derivados se han utilizado como herramienta clave para la detección, seguimiento, gestión y uso futuro de las tierras marginales (ML). Actualmente, no existe una definición única y universalmente aceptada del término y existe una gran variedad de sinónimos. En este artículo llevamos a cabo una recopilación de sinónimos y significados que engloban el término, además de proponer una definición universal. Para alcanzar este objetivo, se realiza un resumen del estado del arte de las ML, visualizando las tendencias mediante mapas científicos, basadas en datos bibliográficos de revistas de investigación consolidadas, encontradas en los buscadores Google Scholar, Web of Science (WoS) y Scopus. La revisión bibliográfica realizada muestra que el estudio de las ML se ha realizado tradicionalmente con una base ad hoc centrada en el objetivo a alcanzar. Se discute este aspecto y otras lagunas de conocimiento para analizar el estudio global de las tierras marginales. Debido al amplio espectro de usos en que se han estudiado las tierras marginales, los trabajos se han centrado en la teledetección para su seguimiento y caracterización, centrándose en dos aspectos diferentes: (i) el seguimiento por satélite de las tierras marginales; y (ii) determinación de su potencial en el almacenamiento de carbono mediante teledetección., This work was supported by the Spanish Ministerio de Economía, Industria y Competitividad through the scholarship for Training of Research Staff BES-2017-081920 and the European Commission through the H2020-MSCA-RISE-2018 MAIL project under Grant Agreement 823805.

[EN] In this work, we provide an updated geodetic approach to the Mediterranean Surface Geostrophic circulation based on satellite data. We follow same methodology as in a previous approach by Vigo et al. (2018), but here both the Sea Surface Height (SSH) and the Geoid (N) have been updated by enhanced solutions, and the time period covered has been extended to 23 years, from 1993 to 2015. The main general pattern of circulation is confirmed with respect to previous approach, but the new estimation provides enhanced resolution of the details, and higher variations in the climatology. When compare both satellite data-based approaches to the Mediterranean Surface Geostrophic Circulation (SGC) with Mercator model simulations that assimilates in-situ measurements, our new estimate shows clearly better agreement than the earlier approach. The mean circulation for the studied period, and the climatology of the SGC for the Mediterranean Sea are presented in the context of previous literature., [ES] En este trabajo, proporcionamos una actualización de la circulación geostrófica en superficie del Mediterráneo obtenida a partir de datos de gravedad y altimetría desde satélite. Seguimos la misma metodología que en un enfoque anterior de Vigo et al. (2018), pero aquí tanto la altura de la superficie del mar (SSH) como el geoide (N) se han actualizado usando soluciones mejoradas, y el período de tiempo cubierto se ha ampliado a 23 años, de 1993 a 2015. El patrón general de circulación se confirma con respecto a la aproximación anterior, pero esta nueva estimación proporciona una resolución mejorada en los detalles de pequeña escala, así como mayores variaciones en la climatología. Cuando se comparan ambos enfoques basados los dos en datos satelitales para la Circulación Geostrófica de la Superficie del Mediterráneo (SGC) con las simulaciones del modelo Mercator (que asimila las mediciones in situ), nuestra nueva estimación muestra claramente una mejor concordancia que la aproximación anterior. La circulación media para el período estudiado y la climatología del SGC para el mar Mediterráneo se presentan en el contexto de la literatura previa., We acknowledge the support of all data providers: ESA CCI Sea Level Project for the Altimetry data, DTU SPACE from the Danish National Space Centre for MDT and MSS products, the surface currents from the Mercator Ocean Project, and LEGOS and CERSAT for the Ekman Surface Currents. The work is supported by Spain Ministry of Science, Innovation and Universities grant number RTI2018-093874-B-100. Zid Ferdous is supported by PhD Grant of Ministry of Higher Education and Scientific Research from Algerian Government for residential training abroad.

[EN] In order to monitor the ripeness and composition of wine grape berries and establish an optimal harvest date, the determination of °Brix and pH is vital. This research includes the study of two wine grapes harvests seasons of Cabernet Sauvignon variety: 2017 and 2018. Field data was periodically taken, allowing to follow the phenological state of the vine. Incorporating technological solutions to the fruit sampling process, such as Sentinel-2 images, permits optimizing a handcrafted procedure and gives the possibility of having a more detailed view of the plots. From the images, 12 variables were obtained, composed of 8 bands and 4 spectral indices, which were related to variables extracted from field samples. The °Brix modeling presents an R2 of 69% and 73% in the 2017 and 2018 seasons, respectively. In pH modeling, the 2017 season had low R2 results, reaching 43%, which then improves considerably in the 2018 season, reaching 63,8%. By choosing a model that allows defining the variability of the plot and the possible early or late ripening areas of the vineyard, is not only very useful but also very valuable to reach a constant improvement in production and hence in the wine quality., [ES] Con el fin de monitorear la madurez y composición de las bayas de uva vinífera y determinar una fecha óptima de cosecha, es vital la determinación de °Brix y pH. Esta investigación comprende el estudio de dos temporadas de cosecha de uva vinífera de variedad Cabernet Sauvignon: 2017 y 2018. Periodo en el cual se tomaron periódicamente datos de campo que permitieron seguir el estado fenológico de la vid hasta el momento de la cosecha y posterior vinificación. Incorporar soluciones tecnológicas, como el uso de imágenes satelitales, en este caso Sentinel-2, al proceso de muestreo de fruta, permite optimizar un proceso artesanal, dando la posibilidad de tener una visión más detallada del cuartel, lo que hace más eficiente el trabajo de terreno. Desde las imágenes se obtuvieron 12 variables compuestas por 8 bandas y 4 indicadores (NDVI, NDMI, Clorofila y GNDVI) que se relacionaron con variables extraídas de muestreos de campo. Con dichos datos se seleccionó el mejor modelo de regresión lineal múltiple, utilizando 3 variables para predecir °Brix y pH. La modelación de °Brix presenta un coeficiente de determinación R2 de 69% y 73% en las temporadas 2017 y 2018, respectivamente. En el caso de la modelación de pH, la temporada 2017 tiene bajos resultados de R2, alcanzando un 43%, el cual mejora considerablemente en la temporada 2018, alcanzando un 63.8%. Determinar un modelo que permita definir la variabilidad de la parcela y, por tanto, las posibles zonas de maduración temprana o tardía del viñedo, es de gran utilidad para concretar una mejora en la producción y por ende en la calidad del vino.

Stereo imagery from very high-resolution satellite series can be used to create high-resolution digital surface models (DSMs) with sub-meter spatial resolution. Especially when in-orbit tri-stereo acquisitions are available as provided by the Pléiades constellation, buildings can be reconstructed well even in dense city centres. Unfortunately, such high-quality stereo data are often not available in the image archives and, thus, need to be newly acquired in most cases, leading to long delays and high cost. Especially for rapid mapping or crisis-response applications, high-resolution DSMs would be helpful for tasks such as city modelling and ultimately population estimation. In this work, we test the feasibility of producing DSMs by pairing two archive images, which were not acquired on the same day, in the same orbit or by the same satellite. We tested this approach for 14 images from Port-au-Prince, Haiti, and 12 images from Salzburg, Austria, from which we calculated a total of 136 DSMs. These were evaluated against Lidar DSMs. The resulting DSMs reach a completeness of up to 60%, and partly Median Absolute Deviation values comparable to in-orbit stereo pairs. For best results, the stereo convergence angle should be between 5 and 15°, and the difference in sun angles between the two images should be below 25-30.

Information on pavement layer thickness is very important for determining bearing capacity, estimating remaining life and strengthening planning. Ground-penetrating radar (GPR) is a nondestructive testing (NDT) method used for determining the continuous pavement layer thickness in the travel direction. The data obtained with GPR in one survey line is suitable for the needs of repair and rehabilitation planning of roads and highways, but not for wider traffic areas such as airfield pavements. Spatial representation of pavement thickness is more useful for airfield pavements but requires a 3D model. In the absence of 3D GPR, a 3D model of pavement thickness can be created by additional processing of GPR data obtained from multiple survey lines. Five 3D models of asphalt pavements were created to determine how different numbers of survey lines affect their accuracy. The distance between survey lines ranges from 1 to 5 m. The accuracy of the 3D models is determined by comparing the asphalt layer thickness on the model with the values measured on 22 cores. The results, as expected, show that the highest accuracy is achieved for the 3D model created with a distance of 1 m between survey lines, with an average relative error of up to 1.5%. The lowest accuracy was obtained for the 3D model created with a distance of 4 m between the survey lines, with an average relative error of 7.4%.

[EN] Groundwater is one of the most important hydric resources of the Spain territory. Nevertheless, heavy groundwater withdrawal generates severe consequences, being land subsidence one of them. The Interferometric Synthetic Aperture Radar (InSAR) technique have been recently exploited to detect and monitor aquifer related deformations. In the present work, relationship between piezometric levels drawdowns and land subsidence has been studied for the higher withdrawals areas within Almonte-Marismas aquifer system (which holds the Doñana Natural Space). Four datasets of radar satellite images, obtained from Sentine-1 satellite, have been processed using the InSAR technique in the period 2014 - 2020. Results show that in some of these areas, like those surrounding El Rocío and Matalascañas villages, the correlation between these two variables is high., [ES] El agua subterránea es uno de los recursos hídricos más importantes en el territorio español. La gran cantidad de agua que se retira de ellos puede tener graves consecuencias, entre las que destaca, en algunos acuíferos, la subsidencia del terreno. La técnica de interferometría radar (InSAR), ha sido desarrollada en las últimas décadas para detectar y monitorear las deformaciones relacionadas con los acuíferos. En este trabajo se estudia la posible relación existente entre la variación de los niveles piezométricos y el movimiento del terreno en zonas con grandes extracciones del acuífero Almonte-Marismas (sobre el que se ubica el Espacio Natural de Doñana). Para ello, se han analizado los datos de deformación del terreno obtenidos del satélite Sentinel-1 en el periodo 2014-2020 Los resultados muestran que, en alguna de estas zonas, como las cercanas a las poblaciones de El Rocío y Matalascañas, la correlación entre ambas variables es alta., Este trabajo es parte de las actividades subvencionadas dentro del Sistema Nacional de Garantía Juvenil (PEJ2018-002477), financiado por la Fundación Tripartita para la Formación en el Empleo, la iniciativa YEI (Youth Employment Initiative) y el Fondo Social Europeo (FSE). Los datos Copernicus Sentinel-1 se obtuvieron y procesaron en la plataforma GEP de la ESA en el marco del GEP Early Adopters Programme. Agradecemos al IGME y a la CHG por proporcionar los datos de piezometría, así como a la Junta de Andalucía por suministrar los datos meteorológicos.

3D point cloud data from data acquisition techniques such as terrestrial photogrammetry, close range photogrammetry (CRP) and light detection and ranging (LiDAR) play a major role in heritage becau...

[EN] The island of La Palma is one of those with the highest potential risk in the Canary archipelago, therefore it is important to carry out an in-depth study to define its state of volcanic activity. This has been done using satellite radar observations and a state-of-the-art original interpretation technique. Both things have made it possible to detect the beginning of the volcanic reactivation on the island of La Palma, probably decades before a possible eruption. Its temporal evolution shows a changing spatial and temporal nature of volcanic deformation with great spatial resolution and over a prolonged period of time (2009-2020), providing information on the dynamic nature of the associated processes. The geodetic techniques used allow detecting the fluid migration induced by the injection of magma in depth and identifying the existence of dislocation sources under the Cumbre Vieja volcano that could be associated with future landslides, making it necessary to continue with the monitoring of this reactivation process using these and other techniques., [ES] La isla de La Palma es de las de mayor riesgo potencial del archipiélago canario, siendo por tanto importante realizar un estudio en profundidad que permita definir su estado de actividad volcánica. Esto se ha realizado usando observaciones radar de satélite y una técnica de interpretación original de última generación. Ambas cosas han permitido detectar el inicio de la reactivación volcánica en la isla de La Palma, probablemente décadas antes de una posible erupción. Su evolución temporal muestra una naturaleza cambiante de la deformación volcánica, tanto espacial como temporalmente. El uso de imágenes radar permite obtener resultados con una gran resolución espacial y en un periodo de tiempo prolongado (2009-2020), obteniendo información sobre la naturaleza dinámica de los procesos asociados. Las técnicas geodésicas empleadas permiten detectar la migración de fluidos inducida por la inyección de magma en profundidad e identificar la existencia de fuentes de dislocación bajo el volcán Cumbre Vieja que podrían estar asociadas con futuros deslizamientos, siendo por tanto necesario continuar con la monitorización de este proceso de reactivación utilizando estas y otras técnicas., Esta investigación ha sido financiada por el proyecto de investigación DEEP-MAPS (RTI2018-093874-B-100) del Ministerio de Ciencia, Innovación y Universidades. También ha sido parcialmente financiado por el proyecto del CSIC 201530E019, el proyecto GEOSIR (AYA2010-17448) del Ministerio de Ciencia e Innovación y el proyecto del MINECO CGL2017-86241-R. Agradecemos a DARES S.L por la licencia de uso del software interferométrico CPT en este studio. Este trabajo representa una contribución a la plataforma interdisciplinar del CSIC PTI TELEDETECT.

[EN] Due to their oceanographic and climatic ecological characteristics, the coastal areas of the Valparaíso Region of Chile are of great importance for the country's tourist, economic, and environmental development. The region's coasts have been affected by extreme events since 2015, with recurrent swells that have increased between 10% and 25% compared to previous years, causing the interruption of the annual dynamic process of the beaches accentuated by anthropic interventions on beaches, wetlands and coastal dunes that promote coastal degradation. This work aims to characterize which part of the beaches and at what time of year there is a higher risk of severe erosion in the immediate areas to the coast and explain its causes based on satellite images of medium resolution satellite images. 128 SDS were extracted with Landsat 8 OLI and Sentinel 2 images with systems SHOREX. Average widths calculated for the series in each of the seasons. Recording the minimum widths in the proximal areas with averages of 12.3 m; 23.6 m and 21.2 m Concón Bay, Reñaca Beach and Algarrobo bay, respectively showing critical or problematic states. The dominant direction of the waves and the geographical disposition of the three beaches seems evident that there is a robust longitudinal transport to the north that generates less sediment accumulation in the proximal areas. The seasonal variation of the beaches distinguishes by more energetic conditions in winter than in summer. But they are also influenced by rapid episodic periods, low atmospheric pressure systems from the north and south, swells and tropical storms. Hence, it is unlikely that the variations in the width of the beach are only due to winter-summer energetic conditions. [ES] Las áreas costeras de la región de Valparaíso de Chile por sus características oceanográficas, climáticas y ecológicas son de gran importancia para el desarrollo turístico, económico y ambiental del país. Las costas de la región se han visto afectadas por eventos extremos desde 2015, con marejadas recurrentes que han aumentado respecto a años anteriores entre el 10% y 25%. Esto ha provocado la interrupción del proceso dinámico anual de las playas, acentuado por las intervenciones antrópicas sobre estos ambientes costeros, humedales y dunas que promueven su degradación. El trabajo que se presenta tiene como objetivo caracterizar en qué parte de las playas y en qué momento del año hay un riesgo más alto de erosión grave en las áreas inmediatas a la costa, así como tratar de explicar sus causas apoyándose en la utilización de imágenes satelitales de resolución media. Se extrajeron 128 SDS con imágenes Landsat 8 OLI y Sentinel 2 con el sistema SHOREX. Se calcularon los valores promedio de anchura de playa para la serie en cada una de las temporadas registrando anchuras mínimas en las zonas proximales de 12,3 m; 23,6 m y 21,2 m para la Bahía de Concón, Playa Reñaca y Bahía de Algarrobo respectivamente, demostrando estados críticos o problemáticos. La dirección dominante del oleaje y la disposición geográfica de las tres playas hace evidente la existencia de un fuerte transporte longitudinal hacia el norte que genera que las áreas proximales presenten menor acumulación de sedimentos. La variación estacional de las playas se caracteriza por condiciones más energéticas en invierno que en verano. No obstante, se ven también influenciadas por periodos episódicos rápidos, sistemas de bajas presiones atmosféricas del norte y del sur, así como marejadas y tormentas tropicales que se suman al moldeamiento de las playas. Este trabajo ha sido financiado por la Agencia Nacional de Investigación y Desarrollo (ANID) a través del FONDEF IDeA I+D 2019 – Desafío País Adaptación al Cambio Climático y Desastres Naturales. Código Proyecto ID19I10361. Agradecimiento a los practicantes de Escuela de Geología de la Universidad Mayor por su colaboración en la toma de datos en campo y procesamiento de datos sedimentarios. Álvaro Millamán, Maximiliano Parrao, Catalina Cerda, Nicolás Rodríguez, a las asistentes, Natalia Medina, Roxana Mansilla. Al IHC Cantabria que nos ha cedido datos de oleaje y marea de la zona.

Recent rapid population growth and increasing urbanisation have led to fast vertical developments in urban areas. Therefore, in the context of the dynamic property market, factors related to the third dimension (3D) need to be considered. Current hedonic price modelling (HPM) studies have little explicit consideration for the third dimension, which may have a significant influence on modelling property values in complex urban environments. Therefore, our research aims to narrow the cognitive gap of the missing third dimension by assessing both 2D and 3D HPM and identifying important 3D factors for spatial analysis and visualisation in the selected study area, Xi&rsquo, an, China. The statistical methods we used for 2D HPM are ordinary least squares (OLS) and geographically weighted regression (GWR). In 2D HPM, they both have very low R2 (0.111 in OLS and 0.217 in GWR), showing a very limited generalisation potential. However, a significant improvement is observed when adding 3D factors, namely view quality, sky view factor (SVF), sunlight and property orientation. The obtained higher R2 (0.414) shows the importance of the third dimension or&mdash, 3D factors for HPM. Our findings demonstrate the necessity to include such factors into HPM and to develop 3D models with a higher level of details (LoD) to serve more purposes such as fair property taxation.

Characterizing and monitoring changes in biogenic 3-dimensional (3D) structures at multiple scales over time is challenging within the practical constraints of conventional ecological tools. Therefore, we developed a structure-from-motion (SfM)-based photogrammetry method, coupled with inspection and mesh processing software, to estimate important ecological parameters of underwater worm colonies (hummocks) constructed by the sabellariid polychaete Sabellaria alveolata, using non-destructive, 3D modeling and mesh analysis. High resolution digital images of bioconstructions (hummocks) were taken in situ under natural conditions to generate digital 3D models over different sampling periods to analyse the morphological evolution of four targeted hummocks. 3D models were analysed in GOM Inspect software, a powerful and freely available mesh processing software to follow growth as well as morphology changes over time of each hummock. Linear regressions showed 3D models only slightly overestimated the real dimensions of the reference objects with an average error < 5% between measured and model-estimated dimensions for both length and volume. Manual inspection of models and semi-automated surface-to-surface comparison allowed the computation of important metrics linked to the ecology of temperate reefs such as volume, surface area, surface complexity/rugosity, number and size of holes and creeks and the mean density of living worms per colony. Moreover we demonstrated the reliability of 3D surface complexity estimates against two linear rugosity measures: a traditional and a virtual variant of the ‘chain-and-tape’ method. Finally, besides 3D models deviation analysis via surface comparison, a Bayesian latent variable model approach was adopted to highlight the significative effects of sea state conditions on S. alveolata hummocks metrics. We demonstrated without damaging the benthic organisms that SfM approach allow continuous study of temperate bioconstruction leading to a fine description of short-term structural modification mediated by hydrodynamics, making this technique accessible and repeatable to many other areas of ecological research.

The paper presents an investigation about the combination of multispectral and 3D imaging aiming at the analysis of the condition and preservation of an ancient vase. Visible-reflected (VIS) and -induced luminescence (UVL) images are mapped to 3D models produced with image- and range-based 3D modelling techniques. The case study is an Attic vase, part of the pottery collection of the Landesmuseum Rudolfinum (Carinthia, Austria) and temporarily stored in the Institute of Archaeology of the University of Graz, Austria. The aim of this study is to exploit the added-value provided by mapping multispectral imaging onto 3D geometry for a comprehensive knowledge of the condition of a restored Cultural Heritage (CH) item., International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, XLII-2, ISSN:1682-1750, ISSN:2194-9034, ISSN:1682-1777

The derivation of the radiative budget of urban environments has gained a high interest in the recent years as an essential part of the global energy budget of big cities. Urban 3D (three-dimensional) heterogeneity hampers its assessment with in-situ measurements, which stresses the interest of Earth Observation (EO) satellites. Improvements in remote-sensing technology and 3D urban databases open the way to new deterministic approaches. This paper presents a new method that derives maps of urban shortwave exitance, albedo and radiative budget $$Q_{SW}$$* from EO satellite images (e.g. Sentinel 2, Landsat-8), using the discrete anisotropic radiative transfer model. In a preliminary step, it derives maps of urban material optical properties from an EO satellite image, at the spatial resolution of this EO image. The method is applied to the city of Basel, Switzerland, in the frame of the European Community H2020 URBANFLUXES (www.urbanfluxes.eu) project which aims at improving our knowledge on anthropogenic heat fluxes in European cities. Results are very encouraging. Indeed, urban $$Q_{SW}$$* derived from 234 EO satellite images, ranging from 200 to 800 W/m2 through the year, is very close to in-situ measured $$Q_{SW}$$*: ≈15 W/m2 temporal root mean square error (i.e. 2.7% mean relative difference) relative to measurements.

The project is part of the wider application and subsequent spread of innovative digital technologies involving robotic systems. Modern society needs knowledge and investigation of the environment and of the related built landscape; therefore it increasingly requires new types of information. The goal can be achieved through the innovative integration of methods to set new analysis strategies for the knowledge of the built heritage and cultural landscape. The experimental cooperation between different disciplines and the related tools and techniques, which this work suggests for the analysis of the architectural heritage and the historical territory, are the following: – 3D metric survey techniques with active and passive sensors – the latter operating in both terrestrial mode and by aerial pointof view. In some circumstances, beyond the use of terrestrial LiDAR, even the newest mobile mapping system using SLAMtechnology (simultaneous localization and mapping) has been tested. – Techniques of non-destructive investigation, such as geophysical analysis of the subsoil and built structures, in particularGPR (Ground Penetrating Radar) techniques. – Historic and stratigraphic surveys carried out primarily through the study and interpretation of documentary sources,cartography and historical iconography, closely related to the existing data or latent material. The experience through the application of these techniques of investigation connected to the built spaces and to the manmade environments has been achieved with the aim of improving the ability to analyse the occurred transformations/layers over time and no longer directly readable or interpretable on manufactured evidence.