Search results for " Photogrammetry"
showing 10 items of 75 documents
Monitoraggio delle deformazioni della cupola del Teatro Massimo di Palermo con l’impiego di tecniche topografiche e fotogrammetriche integrate.
2012
L’articolo riporta i primi risultati di uno studio finalizzato al monitoraggio delle deformazioni della cupola del Teatro Massimo di Palermo provocate dalle dilatazioni termiche, con l’impiego di tecniche topografiche e fotogrammetriche integrate. In particolare, sono state utilizzate due stazioni totali robotizzate e sistemi di fotogrammetria digitale di elevata precisione. Per correlare gli spostamenti dei carrelli sui quali poggia la struttura in acciaio della cupola con i gradienti termici, sono state acquisite immagini termiche diversificate. L’obiettivo principale del lavoro consisteva nel confronto delle due tecniche di rilievo in relazione a misure di deformazione di entità molto ri…
As-built graphic documentation of the Monumento a la Tolerancia. Validation of low-cost survey techniques
2020
[EN] The Monumento a la Tolerancia is an emblematic sculpture realized by Eduardo Chillida, a perfect example for the documentation of sculptures with uniform textures, non-reflective colours and with poorly elaborated shapes through the implementation of various photogrammetric tools, as well as using different applications for processing phase. The basic data are photos taken quickly and without an accurate previous study, which is why the implementation of any target was not foreseen. In order to prove the results different kind of analysis were conducted. The first type was carried out analysing the results obtained from different software, with the use of the same instrument. The secon…
Two photogrammetric methods for measuring flat elements in buildings under construction
2008
Usually, determining the dimensions of flat surfaces in buildings under construction, such as window cavities and facade coating materials, are done by direct measuring methods using tapes and plummets. Sometimes these methods suppose a slow and highly risky work for operators. This research proposes the substitution of these procedures by indirect methods based on close range photogrammetry and laser distance measurement. First, we show the design, construction and calibration of a system composed by a digital camera and a lasermeter mounted on a support with multiple turning positions. Next, two different facade element measuring methodologies are shown. The first method is based on takin…
Control of structural problems in cultural heritage monuments using close-range photogrammetry and computer methods
2005
This paper deals with the conservation of monumental buildings. Several methods used for the architectonic documentation are analysed in this study. Computers methods and close-range photogrammetry are proposed as a preventive method which allows to detect, measure and track the temporal evolution of some structural problems detected, and also to assess the degree of conservation of the materials employed. A group of monuments belonging to the Spanish historical heritage is analysed. In order to carry out the analysis a wire-frame model and a photo-realistic textured model were made. Work focused later on the area where structural problems were more acute.
Bed Topography Reconstruction in a Large Amplitude Meandering Flume: Application of Close Range Photogrammetry
2014
Natural rivers are characterized by continuous variations in bed topography, especially along curved reaches. High resolution topographic data are necessary to analyze the mutual interactions between the downstream flow and the cross-stream flow, which determine the distribution of the bed-shear stress along the channel. Because of the difficulty in acquiring good and accurate data in rivers, the major part of studies have been conducted in laboratory flumes. This paper reports on a laboratory study in which the automatic digital photogrammetric survey was applied to derive the high-resolution Digital Surface Model (DSM) of the bed topography in a large amplitude meandering flume. In order …
Evaluation of capabilities of fuzzy logic classification of different kind of data
2008
In this paper, in order to evaluate the capability of several data, acquired by different sensors, some object-oriented classification tests have been carried out. In particular, the results obtained with two RGB ortophotos, acquired with traditional methodology, have been compared with the ones obtained with two QuickBird images and with the ones obtained by ADS40 pushbroom sensor. The object classification is based on two next steps: The classification to objects is based on two next steps: the decomposition of the whole image in dimension objects bigger than the pixel, procedure called segmentation, and the next classification with Fuzzy logic. This approach provides more reliable result…
Assessing Seagrass Restoration Actions through a Micro-Bathymetry Survey Approach (Italy, Mediterranean Sea)
2022
Underwater photogrammetry provides a means of generating high-resolution products such as dense point clouds, 3D models, and orthomosaics with centimetric scale resolutions. Underwater photogrammetric models can be used to monitor the growth and expansion of benthic communities, including the assessment of the conservation status of seagrass beds and their change over time (time lapse micro-bathymetry) with OBIA classifications (Object-Based Image Analysis). However, one of the most complex aspects of underwater photogrammetry is the accuracy of the 3D models for both the horizontal and vertical components used to estimate the surfaces and volumes of biomass. In this study, a photogrammetry…
Use of new technique of image based aimed to perspective return
2014
The diffusion of Image-based 3D modeling techniques, through image-based free, low cost and open source software, have increased drastically in the past few years, especially in Cultural Heritage domain (Architecture, Archeology, Urban planning) [2, 3]. Computer vision techniques use photographs from dataset collection to rapidly build detailed 3D models. The simultaneous applications of different algorithms (MVS), the different techniques of image matching, feature extracting and mesh optimization are inside an active field of research in computer vision. Computer vision techniques - Structure from Motion (SfM)- allow to fulfill detailed 3D models from photos dataset collections. The resul…
Integrated surveying techniques in cultural heritage documentation
2007
This paper is focused on integration between laser scanning data, CAD modelling and photogrammetric data collected during the survey of one façade of the monument called “Quattro Canti” in the historic centre of Palermo. The investigation has been directed to the production of a 3D photorealistic model of the monument. The “Quattro Canti” monument is formed by four cylindrical façades facing the square where the older streets of Palermo intersect; each façade has a symbolic reference to one of the seasons and is divided in four levels. The façade called “Canto dell’Autunno” has been surveyed both with laser scanning and with photogrammetric techniques. Laser scanning data have been collecte…
Integration of terrestrial laser scanning and UAV-SFM technique to generate a detailed 3D textured model of a heritage building
2020
The digital twin is among the Top 10 of the strategic technological trends for the period 2007-2019, and it represents a powerful tool for the conservation and enhancement of cultural heritage. It reproduces with "precision" a physical asset, thus allowing to investigate its structure and to analyze the deformations that occur over the years. Various techniques have been introduced to obtain high-resolution 3D models. Among these, the Terrestrial Laser Scanner (TLS) is widely recognized as the gold standard to generate accurate 3D metric reconstructions. TLS allows acquiring a lot of data (point cloud) in a fast way, being not in physical contact with the objects of investigation. By integr…