Search results for "photonics"
showing 10 items of 802 documents
FROM SURVEY TO MODEL, AND RETURN. THE CASE OF THE PARMA BAPTISTERY
2019
Abstract. Although this is not always the common practice, the survey should be an essential preliminary stage to any operation of restoration, enhancement and promotion of cultural heritage. Today, various surveying techniques make it possible to collect large amounts of data quickly and to provide a complete three-dimensional representation of extremely complex artefacts. In fact, 3D models allow a much richer description than traditional 2D representations. However, these survey techniques (laser scanner and photogrammetry above all) necessarily imply that the data that must be elaborated during the processing phase increase dramatically. It is therefore essential to identify methods and…
HIGH-RESOLUTION SURFACE AND BED TOPOGRAPHY MAPPING OF RUSSELL GLACIER (SW GREENLAND) USING UAV AND GPR
2020
Abstract. This study presents the detailed survey of the northern marginal part of Russell Glacier, SW Greenland using the combination of unmanned aerial vehicle (UAV) photogrammetry and low-frequency ground penetrating radar (GPR) measurements. Obtained digital elevation model (DEM) and ice thickness data from GPR data allowed the generation of high precision subglacial topography model. We report uncertainties arising from GPR, GPS, and DEM suggesting sufficient accuracy for the reconstruction of glacier bed topography. GPR data and generated subglacial topography model does not reveal any possible Nye channel that could be incised into the bedrock, however, we were able to detect englaci…
FROM SFM TO 3D PRINT: AUTOMATED WORKFLOW ADDRESSED TO PRACTITIONER AIMED AT THE CONSERVATION AND RESTAURATION
2017
Abstract. In In the last years there has been an increasing use of digital techniques for conservation and restoration purposes. Among these, a very dominant rule is played by the use of digital photogrammetry packages (Agisoft Photoscan, 3D Zephir) which allow to obtain in few steps 3D textured models of real objects. Combined with digital documentation technologies digital fabrication technologies can be employed in a variety of ways to assist in heritage documentation, conservation and dissemination. This paper will give to practitioners an overview on the state of the art available technologies and a feasible workflow for optimizing point cloud and polygon mesh datasets for the purpose …
3D survey in complex archaeological environments: An approach by terrestrial laser scanning
2018
Abstract. The survey of archaeological sites by appropriate geomatics technologies is an important research topic. In particular, the 3D survey by terrestrial laser scanning has become a common practice for 3D archaeological data collection. Even if terrestrial laser scanning survey is quite well established, due to the complexity of the most archaeological contexts, many issues can arise and make the survey more difficult. The aim of this work is to describe the methodology chosen for a terrestrial laser scanning survey in a complex archaeological environment according to the issues related to the particular structure of the site. The developed approach was used for the terrestrial laser s…
3D VIRTUAL CH INTERACTIVE INFORMATION SYSTEMS FOR A SMART WEB BROWSING EXPERIENCE FOR DESKTOP PCS AND MOBILE DEVICES
2018
Abstract. Recently, the diffusion of knowledge on Cultural Heritage (CH) has become an element of primary importance for its valorization. At the same time, the diffusion of surveys based on UAV Unmanned Aerial Vehicles (UAV) technologies and new methods of photogrammetric reconstruction have opened new possibilities for 3D CH representation. Furthermore the recent development of faster and more stable internet connections leads people to increase the use of mobile devices. In the light of all this, the importance of the development of Virtual Reality (VR) environments applied to CH is strategic for the diffusion of knowledge in a smart solution. In particular, the present work shows how, s…
SCAN-TO-BIM FOR THE MANAGEMENT OF HERITAGE BUILDINGS: THE CASE STUDY OF THE CASTLE OF MAREDOLCE (PALERMO, ITALY)
2020
Abstract. Conservation and preservation of heritage buildings require the knowledge and sharing of a great deal of data and information about buildings. Such information comes from the different disciplines involved in the restoration and maintenance processes. The integration and use of all this information in a single working environment is a key factor for the success of historical building conservation and management projects. Heritage (or Historic) Building Information Modelling (HBIM) is nowadays the most appropriate tool to collect and manage all data related to Architectural Heritage. The HBIM process requires an in-depth knowledge of the historical building that can be achieved usi…
All polarization-maintaining assively mode-locked yb-doped fiber laser : pulse compression using an anomalous polarization-maintaining photonic cryst…
2019
We report the generation of short pulses at 1 μm using an all-polarization-maintaining (PM) fiber configuration. The pulses are provided by an all normal-dispersion Fabry-Perot Yb-doped cavity and are compressed with an anomalous polarization-maintaining photonic crystal fiber (PM PCF). Opposed to standard configurations; here the filtering action is solely performed by the finite bandwidth of the gain medium. The laser generates 8 ps width sech 2 profile pulses at 1046.8 nm with a −10 dB bandwidth of 5.9 nm. After compression using the PM PCF, pulses with an FWHM of 3 ps were obtained, limited by the actual value of the available anomalous dispersion. We also report the changes in the outp…
3D DIGITAL MODELS FOR A WIDESPREAD MUSEUM: THE RENON’S “BAUERNHÖFE”
2019
Abstract. The aim of the paper is to study the characteristics of different 3D digital models (point clouds, mesh, CSG, BIM) for the realization of a museum of historical buildings widespread in the territory of South Tyrol through the 3D modeling of several farmhouses between the towns of Collalbo, Longomoso and Siffiano, in the Renon area. Therefore, moving from a defined case study, the paper proposes a workflow for model choice, use, and sharing considering also users profile.The objective is to create a system that allows, the sharing, both on site and remotely, of farmhouses digital models, information, images and documents found during the research. The purpose is to enhance the terr…
THE VIRTUALIZATION OF CH FOR HISTORICAL RECONSTRUCTION: THE AR FRUITION OF THE FOUNTAIN OF ST. GEORGE SQUARE IN VALLETTA (MALTA)
2020
Abstract. Improving accessibility to Cultural Heritage (CH) is an increasingly urgent challenge today. It is not only a matter of physical inaccessibility but also temporal, considering that part of CH now lost. Fortunately, the most modern technological tools are helping to break down both space and time barriers. In facts, recent advances in representation, 3D modelling and survey methodologies opened new scenarios for valorization and conservation of CH. In particular, the improvement of quality in resolution and sensor sensitivity of cameras allowed to achieve the right level of 3D reconstruction through digital photogrammetry procedures. In the same field, terrestrial laser scanners (T…
VIRTUAL REALITY FOR HISTORICAL ARCHITECTURE
2019
Abstract. This article shows a first step in the development of an immersive virtual tour of the Cathedral of Palermo, entering the fields of Digital Cultural Heritage and Edutainment. Its purpose is to help people to gain knowledge about the site, highlighting the complex stratifications that have characterized its history.The development of the project has been possible thanks to different phases of work: surveys were initially carried out by laser scanning, then assembled and processed to obtain the 3D model of the current state; at the same time, the model of reconstruction was processed in several phases, based on historical, archival and iconographic sources; both models were, later, …