Interpretando el desplazamiento vertical del suelo desde P-SBAS utilizando la estadística GI* de Getis-Ord

[EN] The Differential Synthetic Aperture Radar Interferometric (DInSAR) algorithm has already shown its importance in volcanicmonitoring. However, it is limited by atmospheric perturbations or temporal decorrelation, implying the existence of lowcoherencerecords that must be discarded. In vast studied areas, with thousands of points unevenly distributed, theinterpretation of the results is usually complicated. This text presents an analysis of the vertical component variation onTenerife island (Canary Islands), from 2005 to 2010, using Getis-Ord Gi* spatial statistic on ENVISAT DinSAR images.The ascending and descending images have been processed using the Parallel Small BAseline Subset (P-SBAS)algorithm, within ESA Grid Processing on Demand cloud environment. From Line of Sight results of both tracks, the verticaldeformation speeds have been calculated over 72,207 points with high coherence (> 0.7). Finally, the Gi* statistic hasbeen applied, obtaining a map with statistical significance, where the high values of Gi*, both positive and negative, implythe spatial clustering of likely ground movements. This map highlights areas with variable vertical kinematics on TenerifeIsland, contributing to understanding of its geodynamics. The displacements obtained coincide with previous studies, evenshowing possible new relationships between some phenomena that should be considered. The Gi* spatial statistic is anefficient and quick tool to extract information in a regional scale kinematic study.[ES] El algoritmo de Interferometría Diferencial con Radar de Apertura Sintética (DInSAR) ha mostrado su utilidad en la detección de cambios en la componente vertical en zonas vulcanológicas activas. Sin embargo, sus limitaciones en la obtención de datos, debido a perturbaciones atmosféricas o decorrelación temporal, implica la existencia de registros con poca coherencia que deben ser desechados. Cuando el área a estudiar tiene una extensión significativa, con miles de puntos distribuidos no homogéneamente por la zona, se complica la interpretación de los resultados. En este texto se presenta el análisis de la variación de la componente vertical de la isla de Tenerife (Canarias), desde 2005 a 2010, empleando la estadística espacial Gi* de Getis-Ord sobre los resultados obtenidos a partir del tratamiento de imágenes ENVISAT. Se han procesado las imágenes ascendentes y descendentes, usando el algoritmo Parallel Small BAseline Subset (P-SBAS), dentro del entorno de la ESA en la nube denominado Grid Processing on Demand. Desde los resultados en línea de vista de ambas trayectorias, se ha calculado las velocidades de deformación vertical para 72.207 puntos con alta coherencia (>0.7). Finalmente, se ha aplicado la estadística espacial Gi* de Getis-Ord a dichas velocidades, obteniendo un mapa con significación estadística, en el que los valores altos del estadístico Gi*, tanto positivos como negativos, implican la agrupación espacial de posibles movimientos del terreno. Este mapa destaca las áreas con cinemática vertical variable para toda la isla de Tenerife, ayudando a la comprensión de la geodinámica de la isla. Los desplazamientos obtenidos son coherentes con otros estudios, incluso muestran posibles relaciones entre algunos fenómenos que deberían ser tenidos en cuenta. Consideramos el uso del estadístico espacial Gi* una herramienta eficaz y rápida para extraer información en un estudio cinemático a escala regional.Barbero, I.; Páez, R.; Torrecillas, C. (2021). Understanding vertical ground displacement from P-SBAS using Getis-Ord GI* statistic. En Proceedings 3rd Congress in Geomatics Engineering. Editorial Universitat Politècnica de València. 163-169. https://doi.org/10.4995/CiGeo2021.2021.12747OCS16316

Diseño de la red andaluza de posicionamiento

Las técnicas geodésicas tienen como finalidad el determinar matemáticamente la forma y dimensiones del globo terrestre, lo que constituye un requisito imprescindible para dotar a las representaciones cartográficas de la debida precisión geométrica. Estas técnicas han conocido un extraordinario avance en las dos últimas décadas con el nacimiento de la geodesia espacial, basada en el uso de satélites artificiales. En tan solo una generación se ha pasado de usar procedimientos astronómicos y geodésicos para determinar con precisión la localización de un punto sobre la superficie terrestre a utilizar una constelación de satélites artificiales que sirven como puntos de referencia fija en el espacio, al modo en que se usaban las estrellas desde la época fenicia

Resolución de ambigüedades GPS: técnicas empleadas y estudios

El fin de este artículo es una profundización en lo que se denomina en argot GPS, Resolución de la Ambigüedad. Ésta, es clave en mediciones GPS cuando se trabaja con técnicas estáticas de corta base o cinemáticas principalmente en tiempo real. La razón estriba en el empleo del observable de la fase de la portadora, afectado éste del término de la Ambigüedad N, esto es, por un número desconocido de completas longitudes de onda que se producen entre el satélite GPS y el receptor. Esta ambigüedad ha de ser determinada con técnicas de aproximación que exploren al completo el potencial de la precisión de las medidas GPS de la fase portadora, dado que es la naturaleza del número entero lo que garantiza la alta precisión

El sistema de información multidisciplinar de apoyo científico (SIMAC) para la isla Decepción (Islas Shetland del Sur, Antártida)

Esta tesis plantea y da solución a la necesidad de compartir información geoespacial entre grupos de trabajos multidisciplinares que acometen sus estudios buscando un mismos fin. Este es el caso de la vulcanología, ciencia multidisciplinar, dónde el control del volcán y el establecimiento de su control para establecer su riesgo natural, es acometido por múltiples disciplinas que deben saber encontrar los datos necesarios para dicha evaluación. Se define un Sistema de Información, cuyo modelo de datos permite alojar todo este tipo de información, así como consultarla y descargarla

Modelo digital de elevaciones de Andalucía de 100m

La edición del Modelo Digital de Elevaciones 100 m. pretende completar las restantes series topográficas del Instituto de Cartografía de Andalucía (I.C.A.) con una descripción numérica del relieve andaluz, necesaria para análisis en tres dimensiones. Los datos de altitud han sido obtenidos del Mapa Topográfico de Andalucía 1:10.000 y se ofrecen con un paso de malla de 1 00 metros en formato ráster (GRID y TIFF), binario (SIN), ASCII (TXT) y de superficie 3D (DTED); todos en coordenadas UTM y con la posibilidad adicional de coordenadas geográficas para los formatos GRID y ASCII. Incluye además tres programas «freeware» como herramientas de explotación y exportación a otros formatos, como el vectorial DXF o el VRML

Determination of volumetric variations and coastal changes due to historical volcanic eruptions using historical maps and remote-sensing at Deception Island (West-Antarctica)

Deception Island is an active volcano in the South Shetland Islands (Antarctic). Its eruptions have been recorded since 1842, the last episode occurring between 1967 and 1970. This study quantifies the geomorphological changes which have taken place as a result of historical volcanic activity on the island. The linear and volumetric results obtained for the Telefon Bay and Craters of 1970s where the Surtseyan eruption took place in 1967 are presented in detail.Ministerio de Educación y Ciencia CGL2005-07589-C03- 01/ANTMinisterio de Educación y Ciencia CGL2004-21547-EMinisterio de Educación y Ciencia CGL2007-28768-E/ANTMinisterio de Educación y Ciencia CTM2009-0725

Reviewing and exploring the qualitative impacts that different market and regulatory measures can have on encouraging energy communities based on their organizational structure

The emergence of energy communities represents a promising option to democratize the energy system by empowering consumers to take a more active role. This can aid in achieving energy and environmental goals as well as encouraging more equitable distribution of costs and revenues between all parties on the energy system. Despite this potential, energy communities are still a nascent solution, the success of which is heavily influenced by regulations. As a result, there are a wide variety of organizational structures for energy communities at this time. This paper provides a review of the policy landscape in Spain as it relates to energy communities. This work also presents a formalized method for characterizing different energy community structures and provides a qualitative assessment of the impacts of different measures to encourage energy communities with respect to their organizational structure. Findings suggest that many market-focused measures, including wholesale, local flexibility, capacity, and multisector market measures favor larger, more integrated communities, while regulatory, legal, and organizational measures, including peer-to-peer trading, aggregation, and self-consumption favor smaller, more distributed communities. Additionally, when developing policies to encourage the growth of energy communities, policymakers should be cognizant of the progression of policies in the context of the desired outcomes for energy community growth specific to the region or country and its goals.Peer ReviewedPostprint (published version

Regional Positioning Services as economic and construction activity indicators: the case study of Andalusian Positioning Network (Southern Spain)

The Andalusian Positioning Network (RAP) is a regional GNSS permanent network in southern Spain that offers two public services for precise positioning: real-time (RAP-IP) and post processing (RAP-FTP). The most of registered users are linked to the construction sector, so the collapse of the housing bubble and the Spanish economic crisis influenced the use of RAP services from 2008. The behavior of these services has differed somewhat, although analysis for the years 2008 to 2013 reveals a general decline. Since 2009 the RAP-FTP service demand fell by 50%, but the RAP-IP service was stable until October 2011, when it began a steep decline in December 2012. Analyzing the temporal demand and the geospatial connections of RAP-IP with economic impact indicators, we found a high linear correlation between this service and jobs in the construction sector (0.98) and permit building (0.96). The real time and associated geoinformation are its main advantages

Generation of a toponimics geodatabase for Andalusia in the andalusian institute of cartography (Southern Spain)

Generating a place-name database is a difficult task. This communication describes the process used to generate a database for toponimics in Andalusia. The source has been an ARC/INFO GIS cartographic data model with 2,745 cartographic sheets at a 1:10,000 scale. We transformed this information into a place-names database with a few macros and a large number of non-automated processes. Furthermore, the Geographic Information Systems helped us to revise errors and in the final design of the geodatabase. The result is a geodatabase with more than 190,000 geo-referenced entries. These entries are going to be the core of the Andalusian Geographic Nomenclature – the next new ICA project

Reconstructing palaeo-volcanic geometries using a Geodynamic Regression Model (GRM): Application to Deception Island volcano (South Shetland Islands, Antarctica)

This article describes a reconstruction made of the palaeo-volcanic edifice on Deception Island (South Shetland Islands, Antarctica) prior to the formation of its present caldera. Deception Island is an active Quaternary volcano located in the Bransfield Strait, between the South Shetland Islands and the Antarctic Peninsula. The morphology of the island has been influenced mainly by the volcanic activity but geodynamics and volcanic deformation have also contributed. A volcanic reconstruction method, the Geodynamic Regression Model (GRM), which includes a terrain deformation factor, is proposed. In the case of Deception Island, the directions of this deformation are NW–SE and NE–SW, and match both the observed deformation of the Bransfield Strait and the volcanic deformation monitored over the last 20 years in the island, using Global Navigation Satellite System (GNSS) techniques. Based on these data, possible volcanic deformation values of 5–15 mm/yr in these directions have been derived. A possible coastline derived from a current bathymetry is transformed, according to values for the chosen date, to obtain the palaeo-coastline of Deception Island of 100 k years ago. Topographic, geomorphologic, volcanological and geological data in a GIS system have been considered, for computation of the outside caldera slope, palaeo-coastline, palaeo-summit height and palaeo digital elevation model (DEM). The result is a 3D palaeo-geomorphological surface model of a volcano, reaching 640 m in height, with an increase of 4 km3 in volume compared to the current edifice, covering 4 km2 more surface area and the method reveals the previous existence of parasite volcanoes. Two photorealistic images of the island are obtained by superposition of textures extracted from a current Quick Bird satellite image also. This technique for reconstructing the terrain of an existing volcano could be useful for analysing the past and future geomorphology of this island and similar locations