Articles by Andrea Angelini

2020 Open Access Article Download PDF BibTeX

The shape of colour. The cave of San Michele on Monte Tancia (Italy)

Marco Carpiceci, Andrea Angelini

Abstract

Starting from the indications derived from the cartographic representation, the goal of the research project described in this paper was to experiment with different tests on the frescoed surfaces of rock-cut architecture for the visualization of the real shape of the subject. For the first time a 3D survey was carried out by the authors in the cave of San Michele on Monte Tancia to test different techniques of processing the numerical models in order to achieve the plane representation of random surfaces, including those with the frescoed plaster. This activity is part of a broader research program related to the investigation of rupestrian architecture, addressing problems of data representation.

«Archeologia e Calcolatori» 2020, 31.2, 233-244; doi: 10.19282/ac.31.2.2020.22

2015 Open Access Article Download PDF BibTeX

Strategie innovative di elaborazione e restituzione dati del castello crociato di Wu’Ayra

Roberto Gabrielli, Andrea Angelini, Damiano Portarena

Abstract

The recent development of camera sensors, the manufacturing of lenses and the accurate algorithms of photogrammetric software allow today to acquire point clouds similar to those generated from a laser scanner. The results are similar: numerical models that contain a variety of information, useful for the final data synthesis. Thanks to the automatic points recognition of photogrammetric algorithms, it is now possible to revise part of digital data previously acquired and use them in new computing strategies. Emblematic is the example of the crusader castle of Wu'Ayra, an important medieval fortress located in the Petra valley in Jordan. Since 2000, in collaboration with the international mission of the University of Florence, a number of surveys aimed at detecting the whole monumental area, the archaeological site, the settlement and the defensive system of the castle were performed by the research team of the Italian ITABC-CNR. Different survey techniques were used during the acquisition step, in order to enhance the main information of the archaeological site and the geomorphology of an extended area particularly complex to be defined. In these 15 years, the team tested several techniques. Thanks to recent software, the team has revised old data, created a defined numerical model of Wu'Ayra, updated and improved the documentation. The Authors illustrate the results of these elaborations and compare them with the other systems used, highlighting the differences and updating the graphic documentation of an important site in the history of the Petra valley. Furthermore, latest data of the architectural structures of the formworks acquired with laser scanner will be presented.

«Archeologia e Calcolatori» 2015, 26, 209-227; doi: 10.19282/ac.26.2015.26

2013 Open Access Article Download PDF BibTeX

Laser scanning e photo scanning. Tecniche di rilevamento per la documentazione 3D di beni architettonici ed archeologici

Andrea Angelini, Roberto Gabrielli

Abstract

Laser scanner and digital photogrammetric systems (photo scanning) must be considered at present two of the main techniques used for archaeological and architectural surveying. The integration of both 3D scanning systems allowed us to improve the scientific knowledge, the management, the use and the safeguarding of Cultural Heritage. The aim of this article is to identify analogies and differences between the two surveying techniques applied to different archaeological contexts. Starting from a general introduction to the concept of measurement and the management of the data acquired from different techniques of surveying, the article focuses on the laser scanner applications with particular attention on the intrinsic properties of the instrument, the problems of measurement and the methodology used during the survey. The second part is focused on the digital photogrammetry applied on a particular archaeological context. Digital photogrammetry was developed and experimented in order to acquire territorial data quickly. The optimization of the working speed, while maintaining accuracy of data, means cost savings and an optimal use of funds. Our workgroup decided to transfer that methodology to the archaeological excavations of Rome Metro Line C in collaboration with some public institutions and private companies. The final results have produced 2D and 3D graphic documentations of all the archaeological area up to highly-accurate ortho-recti ??ed images. Point clouds allowed us to simultaneously view a general 3D model of all open archaeological areas, providing an opportunity for observation and an analysis not possible by other means. Each area can be studied together with the others in a global view of the excavation. Every stratigraphic unit can be displayed in the same area and switched on in the same way as a layer.

«Archeologia e Calcolatori» 2013, 24, 379-394; doi: 10.19282/ac.24.2013.21

2008 Open Access Article Download PDF BibTeX

Antica rete idrologica di Petra. Studio e restauro nell’ottica della conservazione dei beni architettonici

Roberto Gabrielli, Andrea Angelini, Roberto Franchi, Pierre Drap

Abstract

The Petra monumental site is located on the left rim of the Rift Valley in central-southern Jordan. The entire valley, which is tectonic in origin, rests on Late Cambrian quartzarenite rock formations of continental origin. Past research conducted by our team has allowed us to identify the following main causes of the weathering processes: thermal expansion and shrinkage of rocks caused by the great differences in day and night temperatures contribute to the loosening of quartz grains that lead to the disintegration of the rock. Heavy rainfall and above all surface runoff contribute significantly to the removal of weathered materials from the surface. Other forms of decay are caused by the presence of salts along the fractures. Both fieldwork and laboratory analyses performed in the past in a climate chamber have demonstrated that the products usually used in conventional restoration work are not very effective, due to the “extreme” climate and the chemical and physical characteristics of the rocks. The project proposes the realization of a GIS aimed at acquiring complete knowledge of the man-made structures and hydraulic system underlying the routes of the canalisations and identifying the cisterns. This work is meant to contribute a valid support aimed at the restoration, which will involve several different disciplines, including the geological and chemical analysis of the rocks, the topography and the 3D photogrammetry.

«Archeologia e Calcolatori» 2008, 19, 323-341; doi: 10.19282/ac.19.2008.24

2007 Open Access Article Download PDF BibTeX

Tecniche speditive per la ricostruzione tridimensionale dell’area archeologica di Villa Magna

Andrea Angelini, Francesca Colosi, Roberto Gabrielli, Elizabeth Fentress, Cinzia Filippone

Abstract

The article presents the results of the GPS and photographic surveys conducted on the archaeological site of Villa Magna (Anagni, Lazio). The archaeological complex, identified as the imperial residence of Antoninus Pius, occupies an area of about 22 hectares. Presently, the visible remains are divided into two principal nuclei: the northern one, near the church of S. Pietro, and the southern one, occupied by a farmhouse. The aim of the survey was the reconstruction of the morphology of the terrain in order to produce a Digital Terrain Model and to highlight the relationship between natural elements and ancient structures. In order to speed up the work, a new procedure was used. It consists of a Differential GPS used in a kinematic way by mounting the rover antenna on a jeep. In this article the experimental method’s advantages and the problems of acquisition are analysed. Moreover, low altitude photographs of the archaeological excavations were taken using an aerostatic balloon. The photographic system was anchored to the balloon with a radio-controlled device called Picavet. Georeferenced photos can be very useful not only for documenting but also for presenting and exploiting the site.

«Archeologia e Calcolatori» 2007, 18, 141-158; doi: 10.19282/ac.18.2007.08