Search results for "Geodesia"
showing 10 items of 23 documents
Latest developments in rock art recording: towards an integral documentation of Levantine rock art sites combining 2D and 3D recording techniques
2013
This paper presents a further step in the integral documentation of prehistoric rock art, combining 2D and 3D digital recording techniques. Image processing and digital enhancement techniques are an invaluable aid to obtain high quality and accurate 2D recordings, especially when working with faint motifs or complex superimpositions. But what constitutes a real breakthrough is the possibility of combining 2D digital tracings with metric 3D models, providing a whole set of metric outputs that improve our understanding of the motifs in their context and, at the same time, can be used to deliver accurate metric reproductions. The Levantine rock art at Cingle de la Mola Remigia (Ares del Maestr…
Automatic orientation and 3D modelling from markerless rock art imagery
2013
This paper investigates the use of two detectors and descriptors on image pyramids for automatic image orientation and generation of 3D models. The detectors and descriptors replace manual measurements and are used to detect, extract and match features across multiple imagery. The Scale-Invariant Feature Transform (SIFT) and the Speeded Up Robust Features (SURF) will be assessed based on speed, number of features, matched features, and precision in image and object space depending on the adopted hierarchical matching scheme. The influence of applying in addition Area Based Matching (ABM) with normalised cross-correlation (NCC) and least squares matching (LSM) is also investigated. The pipel…
Range-based versus automated markerless image-based techniques for rock art documentation
2014
Nowadays there is a huge proliferation of fully automatic image-based solutions producing either three-dimensional (3D) point clouds or 3D models. However, the reliability of the output is not usually reported and clarified. This paper presents a comparison of the 3D modelling results achieved on two rock art shelters at separate archaeological sites using a high-resolution digital camera. The 3D point clouds were produced using automatic image-based photogrammetric and computer vision software running either locally (FOTOGIFLE and VisualSFM) or through a webbased reconstruction service (Autodesk 123D Catch). The first two automatic approaches are compared with a manual bundle block adjustm…
L'insegnamento delle Scienze topografiche nell'Università di Palermo
2008
Le discipline topografiche hanno registrato negli ultimi anni un profondo rinnovamento grazie soprattutto allo sviluppo delle tecnologie elettroniche ed informatiche. Nuove strumentazioni e metodologie sono state prodotte, sempre più veloci, automatiche, affidabili; basti pensare alla stazione totale, al GPS, al laser a scansione, oppure alla cartografia numerica, alle tecniche fotogrammetriche digitali, a quelle GIS. Un nuovo termine è stato di recente introdotto nel linguaggio tecnico, Geomatica, proprio ad individuare il complesso delle discipline che hanno come oggetto l’acquisizione, l’elaborazione, l’analisi, la visualizzazione e la gestione di informazioni territoriali, e che includo…
Alcuni momenti di storia della geodesia italiana nella Panormitanæ Studiorum Universitas: la scuola geodetica palermitana
2014
Nella storia dell'Università di Palermo, un posto di primo piano assunse la scuola di geodesia nata poco dopo la seconda metà dell'Ottocento, annoverando nomi come Adolfo Venturi, Emanuele Soler e Corradino Mineo. Le sue ricerche teoriche, assieme alle innovative sperimentazioni, portarono la scuola palermitana fra quelle aventi più nomea a livello non solo nazionale ma pure internazionale. In questa breve comunicazione, s'è voluto puntualizzare sull'originalità e la portata delle varie campagne geodetiche condotte dalla suddetta scuola palermitana mediante il pionieristico uso di nuove strumentazioni, e condotte tramite avanzate metodologie empiriche che, nel complesso, contraddistinsero t…
Geometric Inverse Problems
2023
This up-to-date treatment of recent developments in geometric inverse problems introduces graduate students and researchers to an exciting area of research. With an emphasis on the two-dimensional case, topics covered include geodesic X-ray transforms, boundary rigidity, tensor tomography, attenuated X-ray transforms and the Calderón problem. The presentation is self-contained and begins with the Radon transform and radial sound speeds as motivating examples. The required geometric background is developed in detail in the context of simple manifolds with boundary. An in-depth analysis of various geodesic X-ray transforms is carried out together with related uniqueness, stability, reconstruc…
Bibliographia astronómica et geodaética hispánica, 1795-1905 : Volumen I : Introducción, Inventario A-Z
1990
El presente volumen contiene una primera aportación a la bibliografía astronómica y geodésica española comprendida entre los años 1795 y 1905. Incluye 1.198 referencias, de las que más de la mitad son libros y folletos. //. Aquest volum conté una primera aportació a la bibliografia astronòmica i geodèsica espanyola compresa entre els anys 1795 i 1905. Inclou 1.198 referències, de les quals més de la meitat són llibres i fullets.
A combined single range and single image device for low-cost measurement of building facade features
2008
The dimensions of building facades and window apertures are usually determined by making direct measurements using tapes and plummets. This approach, however, has a number of drawbacks including the physical risk to which the persons making the measurements are exposed. This paper proposes an indirect approach based on close range photogrammetry that is inexpensive, simple, fast and safe, and which does not require specialist staff or direct ground control measurements. The method is based on taking a picture using a digital camera and measuring the distance to the object using a handheld laser distance meter. Both items of equipment are mounted on a specially designed support that allows t…
Structural control on the presence and character of calas: Observations from Balearic Islands limestones rock coast macroforms
2013
Calas are characteristic embayed rocky coastline landforms related to steep-sided drowned valleys that were deeply incised during low sea-level stages into carbonate plateaus. This paper studies the factors that control the presence and character of calas in three different islands of the Balearic Archipelago (Mallorca, Menorca and Formentera) by means of Digital Elevation Model (DEM) reconstructions, embayment and catchment morphometric analysis and through the compilation of fault and joint orientations. All islands exhibit emerged carbonate platforms (Upper Miocene in age) characterised by horizontal or very gently-dipping bedding. Two distinct patterns observed at all study sites are th…
Documenting the light sensitivity of Spanish Levantine rock art paintings
2015
[EN] A case study to evaluate the use of microfading spectrometry (MFS) for the study of colored systems found in prehistoric rock art paintings was conducted in the Cova Remígia rock-shelter, Castellón (Spain). This rock shelter is part of the rock art sites of the Mediterranean basin on the Iberian Peninsula included in UNESCO s World Heritage List. Some of the paintings belonging to this group are exposed to environmental factors including natural daylight, wind and rain, depending on the time of the day and the season of the year. Therefore, their preservation is a major concern to stakeholders and researchers responsible for protecting and studying these prehistoric paintings. The expe…