Comparison of Gridded DEMs by Buffering

This research was partially funded by the research project "Functional Quality in Digital Elevation Models in Engineering" (https://coello.ujaen.es/investigacion/web_giic/funquality4 dem/, accessed on 28 July 2021) of the State Research Agency. PID2019-106195RB-I00/AEI/10.13039/ 501100011033.Comparing two digital elevation models (DEMs), S1 (reference) and S2 (product), in order to get the S2 quality, has usually been performed on sampled points. However, it seems more natural, as we propose, comparing both DEMs using 2.5D surfaces: applying a buffer to S1 (single buffer method, SBM) or to both S1 and S2 (double buffer method, DBM). The SBM and DBM approaches have been used in lines accuracy assessment and, in this paper, we generalize them to a DEM surface, so that more area of the S2 surface (in the case of the SBM), or the area and volume (in the case of the DBM) that are involved, more similarly are S1 and S2. The results obtained show that across both methods, SBM recognizes the presence of outliers and vertical bias while DBM allows a richer and more complex analysis based on voxel intersection. Both methods facilitate creating observed distribution functions that eliminate the need for the hypothesis of normality on discrepancies and allow the application of quality control techniques based on proportions. We consider that the SBM is more suitable when the S1 accuracy is much greater than that of S2 and DBM is preferred when the accuracy of S1 and S2 are approximately equal.research project "Functional Quality in Digital Elevation Models in Engineering" of the State Research Agency PID2019-106195RB-I00/AEI/10.13039/50110001103

La construcción descentralizada de datos espaciales: riesgos para la calidad de la información geográfica

En este trabajo se define en qué consiste un marco de «construcción descentralizada» de datos espaciales, el cuál presenta matices diferenciadores respecto a lo que se ha venido denominando «producción descentralizada». Para entender lo que pueden suponer los riesgos de la mala calidad, primeramente, se refuerza la idea de la importancia de los datos espaciales en la toma de decisiones. Posteriormente se identifican y presentan los que entende-mos que, al día de hoy, son los principales retos: producción (comprometerse en mucho), acceso (permitir accesos de calidad), interoperabilidad (posibilitar la utilización y uso legal), metadatos (describir bien los productos), trazabilidad y metacalidad (mantener el linaje e información so-bre la calidad de la calidad) y la preservación (asegurar del uso futuro). El trabajo acaba con unas breves conclusiones en las que se identifican las principales líneas de trabajo (normalización, formación, liderazgo, etc.) para evitar estos riesgo

A method for checking the quality of geographic metadata based on ISO 19157

The authors also wish to express their gratitude to National Center of Geographic Information (CNIG) of Spain for providing the corpus (dated on September 2nd 2016) used to test the methodology, and to the experts that contributed to the manual evaluation of some quality elements.With recent advances in remote sensing, location-based services and other related technologies, the production of geospatial information has exponentially increased in the last decades. Furthermore, to facilitate discovery and efficient access to such information, spatial data infrastructures were promoted and standardized, with a consideration that metadata are essential to describing data and services. Standardization bodies such as the International Organization for Standardization have defined well-known metadata models such as ISO 19115. However, current metadata assets exhibit heterogeneous quality levels because they are created by different producers with different perspectives. To address quality-related concerns, several initiatives attempted to define a common framework and test the suitability of metadata through automatic controls. Nevertheless, these controls are focused on interoperability by testing the format of metadata and a set of controlled elements. In this paper, we propose a methodology of testing the quality of metadata by considering aspects other than interoperability. The proposal adapts ISO 19157 to the metadata case and has been applied to a corpus of the Spanish Spatial Data Infrastructure. The results demonstrate that our quality check helps determine different types of errors for all metadata elements and can be almost completely automated to enhance the significance of metadata.Spanish Government (project TIN2017-88002-R), Regional Government of Aragon (Spain) and the European Social Fund (code T59_17R) and the Regional Government of Andalusia (Spain) for the financial support since 1997 to the research group (Ingeniería Cartográfica) with code PAIDI-TEP-164

Minimum penalized φ-divergence estimation under model misspecification

This paper focuses on the consequences of assuming a wrong model for multinomial data when using minimum penalized φ-divergence, also known as minimum penalized disparity estimators, to estimate the model parameters. These estimators are shown to converge to a well-defined limit. An application of the results obtained shows that a parametric bootstrap consistently estimates the null distribution of a certain class of test statistics for model misspecification detection. An illustrative application to the accuracy assessment of the thematic quality in a global land cover map is included.Ministerio de Economía y Competitivida

Núcleos espaciados: algoritmo para la determinación de un eje medio a partir de multitrazas GNSS 3D

La Información Geográfica Voluntaria (IGV) supone un cambio radical en la obtención y disponibilidad de Información Geográfica. La aportación de millones de usuarios de esta información proporciona un volumen de datos que, usados de forma correcta, es una fuente de un gran valor. En este trabajo se presenta un proceso semiautomático que permite trabajar con este tipo de información, el algoritmo “Núcleos espaciados”. Este algoritmo permite la obtención de un eje medio a partir de un conjunto de multitrazas GNSS 3D tomadas sobre un tramo de carretera. La eficacia del algoritmo ha sido evaluada con un control de calidad posicional del eje obtenido mediante el método de control posicional por elementos lineales de las distancias medias.Esta investigación se ha realizado dentro del proyecto de investigación “Evaluación 3D de elementos lineales de información geográfica (E3DLING)” del Ministerio de Economía y competitividad (BIA2011-23271). Igualmente, se agradece a la Junta de Andalucía la financiación económica del Grupo de Investigación Ingeniería Cartográfica (PAIDI-TEP-164) desde 1997 hasta la fecha

Tratamiento de multitrazas GNSS 3D para la obtención de ejes medios

El uso de los sistemas de navegación se ha difundido mucho y la explotación de sus datos es compleja debido tanto al volumen como a su variabilidad. Este trabajo de revisión presenta una definición de los elementos (trazas) y un análisis de las fuentes de variabilidad, así como los criterios usuales de filtrado de los datos originales. Otro aspecto presentado son los atípicos, éstos se definen y clasifican para el caso de trazas GNSS. La obtención del eje medio se aborda en dos pasos, primero se presentan algoritmos que, a partir de dos polilíneas 3D permiten obtener una solución media y, posteriormente, se presentan otras opciones que permiten obtener una solución de eje medio a partir de un conjunto de trazas.Este trabajo se ha realizado dentro del proyecto de investigación “Evaluación 3D de elementos lineales de información geográfica” del Ministerio de Ciencia e Innovación (BIA2011-23271) cofinanciado por el Fondo Europeo de Desarrollo Regional

Métricas para el control posicional 3D de bases geoespaciales mediante elementos lineales

El control posicional de los productos cartográficos ha venido realizándose a través de la comparación de una muestra de puntos del producto a controlar con los correspondientes puntos extraídos de una fuente de mayor exactitud. Estos métodos y estándares han incluido el cálculo de la exactitud posicional de la componente altimétrica, tanto de forma independiente, como dependiente del resto de componentes. Recientemente, han aparecido algunos trabajos que proponen la realización de este control posicional a través de un conjunto de líneas existentes en la cartografía utilizando como fuente de control las correspondientes líneas obtenidas de una fuente más exacta. Sin embargo, hasta el momento las métricas aplicadas en estos casos se han limitado a las componentes planimétricas. En este trabajo se propone la adaptación de una serie de métricas, planteadas para el control planimétrico, para la realización del control posicional tridimensional mediante elementos lineales. Estas métricas han sido aplicadas a un caso real confirmado los resultados la viabilidad de este tipo de control y de las métricas utilizadas.Este trabajo se ha realizado dentro del proyecto de investigación “Evaluación 3D de elementos lineales de información geográfica” del Ministerio de Ciencia e Innovación (BIA2011-23271)

DEMs: An Approach to Users and Uses from the Quality Perspective

The importance of Digital Elevation Models (DEMs) is great in geosciences, but a general view of users and uses which would bring the concept of quality closer to users is lacking. For this reason, the aim of this paper was three-fold: to obtain better knowledge of users, determine the main application domains of DEMs, and identify main use cases. For this purpose, we used data from two web questionnaires (MR1 and MR2), a search of the ScienceDirect database (MR3) and a Google search (MR4). The data coming from the MR1 resource have offered us a large number of cases in order to characterise the profile of users in Spain. The MR2 resource is an ad hoc designed survey which has allowed us, among other things, to identify those calculations that are more normal; determine that subjective evaluation of quality is of great importance for users; and conclude that there is a high percentage of users who do not use any quality index, and also that the majority of users do not know how to evaluate the influence of poor quality on their work. Through MR3, it was possible to analyse the relationships between relevant items and carry out a semantic analysis of a set of 950 abstracts. From MR4, it can be concluded that the formalisation of applications as use cases is not normal. This paper identifies some research lines in order to offer users a better understanding of the issue of quality regarding DEMs

Experimental verification of hybrid renewable systems as feasible energy sources

[EN] Renewable energies are a central element in the search for energy sustainability, so they are becoming a substantial component of the energy scenario of every country, both as systems connected to the grid or in stand-alone applications. Feasibility of these renewable energy systems could be necessary not only in their application in isolated areas, but also in systems connected to the grid, in this last case when their contribution reaches a substantial fraction of the total electricity demand. To overcome this reliability problem, hybrid renewable systems could become essential and activities to optimize their design should be addressed, both in the simulation and in the experimental areas. In this paper, a laboratory to simulate and verify the reliability of hybrid renewable systems is presented and its application to the feasibility analysis of multicomponent systems including photovoltaic panels, wind generator and biomass gasification plant, plus energy storage in a battery bank, are described.Pérez-Navarro, Á.; Alfonso-Solar, D.; Ariza-Chacón, HE.; Cárcel Carrasco, FJ.; Correcher Salvador, A.; Escrivá-Escrivá, G.; Hurtado, E.... (2016). Experimental verification of hybrid renewable systems as feasible energy sources. Renewable Energy. 86(2):384-391. doi:10.1016/j.renene.2015.08.030S38439186

Bronchoscopist's perception of the quality of the single-use bronchoscope (Ambu aScope4™) in selected bronchoscopies: a multicenter study in 21 Spanish pulmonology services

Background: The disposable bronchoscope is an excellent alternative to face the problem of SARS-CoV-2 and other cross infections, but the bronchoscopist’s perception of its quality has not been evaluated. Methods: To evaluate the quality of the Ambu-aScope4 disposable bronchoscope, we carried out a cross-sectional study in 21 Spanish pulmonology services. We use a standardized questionnaire completed by the bronchoscopists at the end of each bronchoscopy. The variables were described with absolute and relative frequencies, measures of cen‑ tral tendency and dispersion depending on their nature. The existence of learning curves was evaluated by CUSUM analysis. Results: The most frequent indications in 300 included bronchoscopies was bronchial aspiration in 69.3% and the median duration of these was 9.1 min. The route of entry was nasal in 47.2% and oral in 34.1%. The average score for ease of use, image, and aspiration quality was 80/100. All the planned techniques were performed in 94.9% and the bronchoscopist was satisfed in 96.6% of the bronchoscopies. They highlighted the portability and immediacy of the aScope4TM to start the procedure in 99.3%, the possibility of taking and storing images in 99.3%. The CUSUM analysis showed average scores>70/100 from the frst procedure and from the 9th procedure more than 80% of the scores exceeded the 80/100 score