Un estudio sobre las nociones de conservación que tienen estudiantes universitarios

En educación en ciencias, la idea de conservación y los principios asociados presentan dificultades en el aprendizaje. La idea de conservación es central en ciencias, en particular en Física, porque está implicada en principios fundamentales, los cuales resultan útiles para describir y predecir fenómenos. En este trabajo, se propone estudiar, en forma exploratoria, las ideas que tienen los estudiantes universitarios de primer año de Ingeniería, sobre el concepto de conservación. Se diseñó un cuestionario con preguntas abiertas y preguntas cerradas con justificación. Los registros se analizaron a partir de categorías emergentes y categorías encontradas en investigaciones anteriores. Los resultados preliminares muestran que la idea de conservación se asocia a “algo constante”, “inicial igual a final”; también se observa el uso del tiempo como recurso explicativo

Performance evaluation of cots UAV for Architectural Heritage documentation. A test on S.Giuliano Chapel in Savigliano (CN) - Italy

Even more the use of UAV platforms is a standard for images or videos acquisitions from an aerial point of view. According to the enormous growth of requests, we are assisting to an increasing of the production of COTS (Commercial off the Shelf) platforms and systems to answer to the market requirements. In this last years, different platforms have been developed and sell at low-medium cost and nowadays the offer of interesting systems is very large. One of the most important company that produce UAV and other imaging systems is the DJI (Dà-Jiāng Innovations Science and Technology Co., Ltd) founded in 2006 headquartered in Shenzhen – China. The platforms realized by the company range from low cost systems up to professional equipment, tailored for high resolution acquisitions useful for film maker purposes. According to the characteristics of the last developed low cost DJI platforms, the onboard sensors and the performance of the modern photogrammetric software based on Structure from Motion (SfM) algorithms, those systems are nowadays employed for performing 3D surveys starting from the small up to the large scale. The present paper is aimed to test the characteristic in terms of image quality, flight operations, flight planning and accuracy evaluation of the final products of three COTS platforms realized by DJI: the Mavic Pro, the Phantom 4 and the Phantom 4 PRO. The test site chosen was the Chapel of San Giuliano in the municipality of Savigliano (Cuneo-Italy), a small church with two aisles dating back to the early eleventh century

DOCUMENTATION OF COMPLEX ENVIRONMENTS IN CULTURAL HERITAGE SITES. A SLAM-BASED SURVEY IN THE CASTELLO DEL VALENTINO BASEMENT

Underground Built Heritage (UBH) stands out among the existing Cultural Heritage sites as a peculiar scenario. The assets belonging to this type of heritage are typically difficult to manage, exploit, and promote because of a lack of knowledge and documentation. The challenges in documenting built heritage are many and wide-ranging, and the main need must be to provide an accurate and appropriate representation of the surveyed area and its geometric features without employing time-consuming processes. Mobile Mapping Systems (MMSs) are nowadays trending technologies for the geomatics community, proving to be a useful alternative to traditional surveying techniques when taking time and cost constraints into account. The paper focuses on the use of an MMS, the STONEX® X120GO SLAM Laser Scanner system, in documenting a portion of the Castello del Valentino, an articulated and complex architecture located in Turin (Italy). The underground floor of the castle, due to its complexity in terms of accessibility and the challenge it poses for the documentation approach, was chosen as a case study to assess the STONEX® X120GO's capabilities in terms of portability of the instrument, speed of acquisition, as well as completeness and accuracy of the acquired dataset. The results obtained using the MMS technique have been compared to and validated using data from a TLS (Terrestrial Laser Scanner) survey used as a ground reference. The results and considerations reported in this paper demonstrate that MMSs can accurately and completely depict built spaces and their main characteristics and have substantial potential in mapping complex assets

PRELIMINARY EVALUATION OF A COMMERCIAL 360 MULTI-CAMERA RIG FOR PHOTOGRAMMETRIC PURPOSES

The research presented in this paper is focused on a preliminary evaluation of a 360 multi-camera rig: the possibilities to use the images acquired by the system in a photogrammetric workflow and for the creation of spherical images are investigated and different tests and analyses are reported. Particular attention is dedicated to different operative approaches for the estimation of the interior orientation parameters of the cameras, both from an operative and theoretical point of view. The consistency of the six cameras that compose the 360 system was in depth analysed adopting a self-calibration approach in a commercial photogrammetric software solution. A 3D calibration field was projected and created, and several topographic measurements were performed in order to have a set of control points to enhance and control the photogrammetric process. The influence of the interior parameters of the six cameras were analyse both in the different phases of the photogrammetric workflow (reprojection errors on the single tie point, dense cloud generation, geometrical description of the surveyed object, etc.), both in the stitching of the different images into a single spherical panorama (some consideration on the influence of the camera parameters on the overall quality of the spherical image are reported also in these section)

GEOMATIC CONTRIBUTION FOR THE RESTORATION PROJECT OF THE VALENTINO CASTLE GREEN ROOM. FROM DATA ACQUISITION TO INTEGRATED DOCUMENTATION

In the framework of restoration operations, valuable assistance can be supplied from innovative techniques and methods developed in the field of Geomatics. Over the years, this continuous collaboration has produced synergistic and interdisciplinary results that have been successfully contributing to heritage conservation and valorisation. In the case of the current research, thorough multisensory investigations have been performed in order to provide a deeper knowledge of the Green Room of the Valentino Castle in Turin and to support the planning of the future restoration works that will involve this valuable asset. In the framework of this experience, four LiDAR systems have been employed in order to evaluate the different results obtainable from the sensors. Additionally, a complete photogrammetric close-range survey has been carried out, and some tests were completed using a hyperspectral camera. The workflow followed during the current research is described in this paper, and a comparison between the obtained outputs is proposed, focusing on the characteristics of these metric products, useful and sometimes necessary in the framework of the restoration project. Besides, some considerations on the advantages and the issues connected with the use of these reality-based data as a starting point for HBIM (Heritage Building Information Modeling) model generation are proposed, along with some observations about the potentialities of a photogrammetric co-registration approach using spectrum technologies for deterioration/decay detection and monitoring of heritage

THE IPAD PRO BUILT-IN LIDAR SENSOR: 3D RAPID MAPPING TESTS AND QUALITY ASSESSMENT

The main goal of this ongoing research is the evaluation of the iPad Pro built-in LiDAR sensor for large scale 3D rapid mapping. Different aspects have been considered from the architectural surveying perspective and several analyses were carried out focusing on the acquisition phase and the definition of best practices for data collection, the quantitative analysis on the acquired data and their 3D positional accuracy assessment, and the qualitative analysis of the achievable metric products. Despite this paper is a preliminary analysis and deeper studies in various application environment are necessary, the availability of a LiDAR sensor embedded in a tablet or mobile phone, appears promising for rapid surveying purposes. According to test outcomes, the sensor is able to rapidly acquire reliable 3D point clouds suitable for 1:200 architectural rapid mapping; the iPad Pro could represent an interesting novelty also thanks to its price (compared to standard surveying instruments), portability and limited time required both for data acquisition and processing

UAV PHOTOGRAMMETRY AND VHR SATELLITE IMAGERY FOR EMERGENCY MAPPING. THE OCTOBER 2020 FLOOD IN LIMONE PIEMONTE (ITALY)

Heavy rain between the 2nd and 3rd of October 2020 severely affected the area of Limone Piemonte, Piemonte Region (Italy). The consequence of those two days of rain was a flood that, starting from the hamlet of Limonetto severely damaged the areas close to the riverbed of the Vermegnana river and the related hydrographyc network. A synergistic multi-sensor and multi-scale approach for documenting the affected areas using VHR satellite images and UAVs (Uncrewed Aerial Vehicles) is presented. The pro and cons in terms of level of detail and processing strategies are reviewed with a focus on the workflows adopted for processing large UAV datasets. A thorough analysis of the 3D positional accuracy achievable with different georeferentation strategies for UAVs data processing is carried out, confirming that if an RTK (Reale Time Kinematic)-enabled GNSS (Global Navigation Satellite System) receiver is available on the UAV platform and proper acquisition guidelines are followed, the use of GCPs (Ground Control Points) is not impacting significantly on the overall positional accuracy. Satellite data processing is also presented, confirming the suitability for large scale mapping

THE IPAD PRO BUILT-IN LIDAR SENSOR: 3D RAPID MAPPING TESTS AND QUALITY ASSESSMENT

Abstract. The main goal of this ongoing research is the evaluation of the iPad Pro built-in LiDAR sensor for large scale 3D rapid mapping. Different aspects have been considered from the architectural surveying perspective and several analyses were carried out focusing on the acquisition phase and the definition of best practices for data collection, the quantitative analysis on the acquired data and their 3D positional accuracy assessment, and the qualitative analysis of the achievable metric products. Despite this paper is a preliminary analysis and deeper studies in various application environment are necessary, the availability of a LiDAR sensor embedded in a tablet or mobile phone, appears promising for rapid surveying purposes. According to test outcomes, the sensor is able to rapidly acquire reliable 3D point clouds suitable for 1:200 architectural rapid mapping; the iPad Pro could represent an interesting novelty also thanks to its price (compared to standard surveying instruments), portability and limited time required both for data acquisition and processing