Seismic Vulnerability Analysis in 3D City Models (3DCM)

UID/SOC/04647/2013 SFRH/BPD/76893/2011Lisbon is a city with high seismic risk, having been hit in the past by strong earthquakes. That’s the reason why several seismic vulnerability studies have been made devoted to the buildings of the capital, aiming the creation of different scenarios that depend on the magnitude and source location of the earthquake. The results of these studies have been presented as maps resulting from crossing information contained in 2D layers and presented in a GIS environment. 3D City Models (3DCM) intend to associate a database of a city to a rigorous geospatial representation and close to the visible reality in an urban environment, combining geometry and semantics. As such, they may include tools that convey attribute analysis at different levels, allowing the generation of new knowledge on a phenomenon or its effects, not only at the statistical level but also in terms of visual impact on the object. In this project it is intended to extend into the third dimension a seismic vulnerability study of the buildings of Lisbon held in 2D and explore the gains of spatial analysis in 3D representations. The various parameters that contribute to assess seismic vulnerability of buildings may be analyzed individually or simultaneously. The application of this tool will be demonstrated in a pilot area of Lisbon.publishersversionpublishe

O Observatório Astronómico da Escola Politécnica : modelos virtuais para a sua preservação

O último observatório de ensino de interesse histórico em Portugal, que data do final do século XIX, é um dos edifícios mais carismáticos dos Museus da Universidade de Lisboa. Após um século de uso intensivo, o Observatório Astronómico da Escola Politécnica necessita de obras estruturais antes de ser devolvido integralmente à fruição pública. Recentemente, um grupo de estudantes desta Universidade foi envolvido na construção de modelos 3D virtuais para recriar o edifício do Observatório e alguns objetos das suas coleções. A qualidade dos modelos potencia a sua utilização como instrumento de divulgação de uma peça relevante do património histórico-científico da Universidade de Lisboa. Este artigo descreve as várias abordagens adoptadas e compara-as entre si.The Astronomical Observatory of the Lisbon Polytechnic School is the last teaching observatory of historical interest in Portugal. Created in the late nineteenth century, it survives intact in its original design. Given its singularity in the context of scientific heritage, the quality and beauty of its architecture, as well as its privileged location in the Botanical Garden, the Observatory has the potential to become the Museum’s focal point for the promotion of astronomy and its history. After 100 years of intense use, however, the Observatory is highly degraded and needs structural restoration before it can be fully returned to public fruition. Recently, three professors of the Faculty of Sciences of the University of Lisbon decided to involve a group of students in the construction of virtual 3D models to recreate the Observatory building and collections. This article describes the methods used to produce the models and presents a comparison between them

A digital botanical garden: using interactive 3D models for visitor experience enhancement and collection management

Highlights: • A virtual 3D model of a botanical garden was built based on a GIS with plants botanical information and buildings, statues and other assets historical information. • The height and crown diameter of individual trees were determined from watershed operations on aerial LiDAR data. Statues were modelled photogrammetrically. Buildings were modelled procedurally using CGA rules. • Users found realism and information access to be the most positive points. The way of data organisation and the elaborated modelling rules make the product easily extendable for new data and objects. Abstract: Botanical gardens are important spots in urban spaces, both for researchers and for many different kinds of public. Conveying scientific information by means of an attractive digital product, on a pre- or post-visit experience, is a way of captivating the public, especially the younger generation, to the relevance of those gardens as repositories of knowledge and for conservation of plant species diversity. This approach also facilitates communication with the general public and access to historical data. On the other hand, bringing the garden to the desktop of researchers and managers can be an advantage, not only for an overview of the status quo but also in spatial planning matters. This paper describes the production of a 3D dynamic model of the Tropical Botanical Garden in Lisbon on top of a Geographic Information System (GIS). Its development included creating a spatial database to organise data originating from a variety of sources, the three-dimensional (3D) modelling of plants, buildings and statues, the creation of web pages with historic and contextual information, as well as the publication of a number of interactive 3D scenes. Several software packages were used, and the final outputs were published in ArcGIS Online to be explored by the public and researchers (link provided at the end of the text). The data are organised in a database, and most 3D modelling tasks are procedural through Computer Generated Architecture (CGA) rules. Thus, updating information or 3D models can be done without having to repeat all steps, an important feature for a dynamic botanical garden. Challenges and solutions are also addressed, providing a constructive contribution to the further implementation of similar experiences in other botanical gardens. According to a user survey carried out, the realism of the representation and the possibility of easily retrieving information from the objects are the most positive aspects of the project

Application of Multiple Geomatic Techniques for Coastline Retreat Analysis: The Case of Gerra Beach (Cantabrian Coast, Spain)

Producción CientíficaThe beaches of the Cantabrian coast (northern Spain) are exposed to strong winter storms that cause the coastline to recede. In this article, the coastal retreat of the Gerra beach (Cantabria) is analyzed through a diachronic study using the following different geomatic techniques: orthophotography of the year 1956; photogrammetric flights from 2001, 2005, 2010, 2014, 2017; Light Detection and Ranging (LiDAR) survey from August 2012; Unmanned Aerial Vehicle (UAV) survey from November 2018; and terrestrial laser scanner (TLS) through two dates per year (spring and fall) from April 2012 to April 2020. With the 17 observations of TLS, differences in volume of the beach and the sea cliff are determined during the winter (November–April) and summer (May–October) periods, searching their relationship with the storms in this eight-year period (2012–2020). From the results of this investigation it can be concluded that the retreat of the base of the cliff is insignificant, but this is not the case for the top of the cliff and for the existing beaches in the Cantabrian Sea where the retreat is evident. The retreat of the cliff top line in Gerra beach, between 1956 and 2020 has shown values greater than 40 m. The retreat in other beaches of the Cantabrian Sea, in the same period, has been more than 200 m. With our measurements, investigations carried out on the retreat of the cliffs on the Atlantic coast have been reinforced, where the diversity of the cliff lithology and the aggressive action of the sea (storms) have been responsible for the active erosion on the face cliff. In addition, this research applied geomatic techniques that have appeared commercially during the period (1956–2020), such as aerial photogrammetry, TLS, LiDAR, and UAV and analyzed the results to determine the precision that could be obtained with each method for its application to similar geomorphological structures.Junta de Extremadura and European Regional Development Fund (ERDF) grant (GR18053)FCT project- Instituto Dom Luiz (UIDB/50019/2020

Conservación digital del patrimonio cultural y científico: participación de estudiantes universitarios para concienciarles de su importanica

[EN] Cultural heritage is a relevant issue in contemporary society. While its preservation is a challenge, its dissemination, can contribute for an economic balance between costs and benefits. Scientific heritage can be considered as a special domain of cultural heritage, not yet sought by the mass tourism, but worth being preserved as the roots of today’s knowledge. Considering that university students of engineering and computer science traditionally do not address cultural or scientific heritage issues in their syllabus, and that they constitute a layer of young citizens that will come to be influential in the future of society, an effort was undertaken to focus on this theme in disciplines of different courses, allying the learning of technical skills with the natural interest of younger people for 3D and animation for the profit of heritage. The goal was to raise the awareness of this particular group to the importance of maintaining heritage issues, in particular, in a virtual way, both for documentation and for divulgating their existence. Raising funds for buildings’ restoration, attracting the public to visit buildings and collections that are outside the usual tourism routes, contributing to revenue generation, or allowing virtual visits of not accessible issues, complementing physical visits on site, were the general aims of the proposed projects. A survey was undertaken under the participating students to evaluate how the projects influenced their attitude towards heritage. The obtained feedback was very positive: 76% agreed that the project alerted them for the importance of preserving historical and cultural heritage, while 72% considered it was interesting that the topic of digital cultural heritage was used for the assessments of the disciplines.[ES] El patrimonio cultural es un tema relevante en la sociedad contemporánea. Mientras que su conservación es un reto, su difusión puede contribuir a un equilibrio económico entre costes y beneficios. El patrimonio científico puede ser considerado como un dominio especial del patrimonio cultural, y aunque todavía no es buscado por el turismo de masas, vale la pena ser conservado. Teniendo en cuenta que los estudiantes universitarios de ingeniería e informática tradicionalmente no abordan cuestiones de patrimonio cultural o científico en su plan de estudios, y que estos constituyen un grupo de ciudadanos jóvenes que serán influyentes en el futuro de la sociedad, se ha realizado un esfuerzo para centrarse en este tema en las disciplinas de diferentes cursos, uniéndose el aprendizaje de habilidades técnicas con el interés natural de las personas más jóvenes hacia el3D y la animación para el beneficio del patrimonio. El objetivo era aumentar la conciencia de este grupo en particular en la importancia de mantener los temas de patrimonio. La recaudación de fondos para la restauración de edificios, atraer al público a visitar los edificios y colecciones que se encuentran fuera de las rutas turísticas habituales, contribuyendo a la generación de ingresos, o permitir visitas virtuales de cuestiones que no son accesibles, eran los objetivos generales de los proyectos propuestos. Se llevóa cabo una encuesta entre los estudiantes que desarrollaron estos proyectos para evaluar si estos tenían una influencia positiva en su actitud hacia el patrimonio. La información obtenida fue muy positiva: 76% están de acuerdo en que el proyecto les alertó de la importancia de la conservación del patrimonio histórico y cultural,mientras que el 72% consideró que sería interesante que se utilizara el tema del patrimonio cultural digital enlas evaluaciones de las disciplinas.We acknowledge the students Pedro Lopes, Fernando Berenguer, Bogdan Rosu, Robin Burgess, Vitor Pinto, Marine Granger, Inês Gomes, Jorge Gomes, Rui Flores, João Moreira for their work in the models presented in this paper. The projects were partially supported by the R&D Unit BioISI, UID/MULTI/04046/2013 financed through FCT/MCTES/ PIDDAC, by the project PTDC/EMSENE/4525/2014 from FCT, Portugal, and by NEXUS, Spain.Redweik, P.; Cláudio, AP.; Carmo, MB.; Naranjo, JM.; Sanjosé, JJ. (2017). Digital preservation of cultural and scientific heritage: involving university students to raise awareness of its importance. Virtual Archaeology Review. 8(16):22-34. doi:10.4995/var.2017.4629.SWORD223481

Contributions to the design of mobile applications for visitors of Botanical Gardens

Botanical Gardens are among the most visited touristic attractions, offering scientific, educational, cultural and leisure activities to preserve and enhance heritage and disseminating specialised knowledge on science and history. There are several mobile applications (apps) to support visitors of Botanical Gardens, which explore augmented reality technologies to enrich their experience. Our work aims to systematize a set of requirements that must be considered in the development of these apps. We have applied them in the development of an app for a Botanical Garden available for Android and iOS. Preliminary data analysis of the use of our app revealed some characteristics of the visitors and the preferred tours. Meanwhile we are evaluating our app by conducting a user study.info:eu-repo/semantics/publishedVersio

Tower of Belém (Lisbon)–Status Quo 3D Documentation and Material Origin Determination

The Tower of Belém, an early 16th century defense tower located at the mouth of the Tagus river, is the iconic symbol of Lisbon. It belongs to the Belém complex, classified since 1983 as a World Heritage Site by the UNESCO, and it is the second most visited monument in Portugal. On November 1st, 1755, there was a heavy earthquake in Lisbon followed by a tsunami, causing between 60,000 and 100,000 deaths. There is a possibility of a repetition of such a catastrophe, which could bring about the collapse of the structure. This was the reasoning behind the decision to evaluate the Tower of Belém by means of surveys using Terrestrial Laser Scanning and photogrammetry. Until now, there was no high-resolution 3D model of the interior and exterior of the tower. A complete 3D documentation of the state of the Tower was achieved with a cloud of more than 6,200 million 3D points in the ETRS89 PT-TM06 coordinate system. Additionally, measurements were made using a hyperspectral camera and a spectroradiometer to characterize the stone material used in the Tower. The result is a digital 3D representation of the Tower of Belém, and the identification of the quarries that may have been used to extract its stone. The work carried out combines geometrical and material analysis. The methods used may constitute a guide when documenting and intervening in similar heritage elements. Finally, the information contained therein will allow an eventual reconstruction of the Tower in the case of another catastrophe

Remote estimation of target height from unmanned aerial vehicle (UAV) images

This paper focuses on how the height of a target can be swiftly estimated using images acquired by a digital camera installed into moving platforms, such as unmanned aerial vehicles (UAVs). A pinhole camera model after distortion compensation was considered for this purpose since it does not need extensive processing nor vanishing lines. The pinhole model has been extensively employed for similar purposes in past studies but mainly focusing on fixed camera installations. This study analyzes how to tailor the pinhole model for gimballed cameras mounted into UAVs, considering camera parameters and flight parameters. Moreover, it indicates a solution that foresees correcting only a few needed pixels to limit the processing overload. Finally, an extensive analysis was conducted to define the uncertainty associated with the height estimation. The results of this analysis highlighted interesting relationships between UAV-to-target relative distance, camera pose, and height uncertainty that allow practical exploitations of the proposed approach. The model was tested with real data in both controlled and uncontrolled environments, the results confirmed the suitability of the proposed method and outcomes of the uncertainty analysis. Finally, this research can open consumer UAVs to innovative applications for urban surveillanc

Un jardín botánico digital: utilización de modelos 3D interactivos para mejorar la experiencia del visitante y la gestión de las colecciones

[EN] Botanical gardens are important spots in urban spaces, both for researchers and for many different kinds of public. Conveying scientific information by means of an attractive digital product, on a pre- or post-visit experience, is a way of captivating the public, especially the younger generation, to the relevance of those gardens as repositories of knowledge and for conservation of plant species diversity. This approach also facilitates communication with the general public and access to historical data. On the other hand, bringing the garden to the desktop of researchers and managers can be an advantage, not only for an overview of the status quo but also in spatial planning matters. This paper describes the production of a 3D dynamic model of the Tropical Botanical Garden in Lisbon on top of a Geographic Information System (GIS). Its development included creating a spatial database to organise data originating from a variety of sources, the three-dimensional (3D) modelling of plants, buildings and statues, the creation of web pages with historic and contextual information, as well as the publication of a number of interactive 3D scenes. Several software packages were used, and the final outputs were published in ArcGIS Online to be explored by the public and researchers (link provided at the end of the text). The data are organised in a database, and most 3D modelling tasks are procedural through Computer Generated Architecture (CGA) rules. Thus, updating information or 3D models can be done without having to repeat all steps, an important feature for a dynamic botanical garden. Challenges and solutions are also addressed, providing a constructive contribution to the further implementation of similar experiences in other botanical gardens. According to a user survey carried out, the realism of the representation and the possibility of easily retrieving information from the objects are the most positive aspects of the project. Highlights: A virtual 3D model of a botanical garden was built based on a GIS with plants botanical information and buildings, statues and other assets historical information. The height and crown diameter of individual trees were determined from watershed operations on aerial LiDAR data. Statues were modelled photogrammetrically. Buildings were modelled procedurally using CGA rules. Users found realism and information access to be the most positive points. The way of data organisation and the elaborated modelling rules make the product easily extendable for new data and objects.[ES] Los jardines botánicos son enclaves importantes en los espacios urbanos, tanto para los investigadores como para diferentes tipos de público. Transmitir la información científica mediante un producto digital atractivo, en una experiencia previa o posterior a la visita, es una forma de transmitir al público, especialmente a los más jóvenes, la relevancia de esos jardines como repositorios de conocimiento para la conservación de la diversidad de las especies vegetales. Este enfoque también facilita la comunicación con el público en general y el acceso a los datos históricos. Por otro lado, un acceso virtual del jardín tanto de los investigadores como de los gestores supondría una gran ventaja, no sólo para tener una visión global del estado actual, sino también para cuestiones referentes a la planificación territorial. El presente trabajo describe la producción de un modelo dinámico 3D del Jardín Botánico Tropical de Lisboa sobre un Sistema de Información Geográfica (SIG). Su desarrollo incorpora una base de datos espacial que organiza los datos procedentes de diversas fuentes, la modelización 3D de la vegetación, edificios y estatuas, páginas web con información histórica y contextual, así como la publicación de una serie de escenas interactivas en 3D. Para ello, se utilizaron varios programas informáticos y los resultados finales se publicaron en ArcGIS Online para que el público y los investigadores pudieran explorarlos (el enlace se proporciona al final del texto). Los datos se organizan en una base de datos y la mayoría de las tareas de modelado en 3D son procedimentales mediante reglas de Computer Generated Architecture (CGA). De este modo, la actualización de la información o de los modelos 3D puede realizarse sin tener que repetir todos los pasos, lo cual es importante para un jardín botánico dinámico. Con esta investigación se abordan retos y soluciones, contribuyendo de forma constructiva a la puesta en práctica de experiencias similares en otros jardines botánicos. Según una encuesta realizada a usuarios relacionados con los jardines botánicos, el realismo de la representación y la posibilidad de recuperar fácilmente la información de los objetos son los aspectos más positivos del proyecto.This work was funded by the Portuguese Fundacao para a Ciencia e a Tecnologia (FCT) I.P./MCTES through national funds (PIDDAC)–UIDB/50019/2020 and UIDB/00329/2020.Redweik, P.; Reis, S.; Duarte, MC. (2023). A digital botanical garden: using interactive 3D models for visitor experience enhancement and collection management. Virtual Archaeology Review. 14(28):65-80. https://doi.org/10.4995/var.2023.176296580142