Search results for "geofisica applicata"
showing 10 items of 169 documents
Influence of different array datasets on reliability of electrical resistivity tomography
2015
The goal of this work is to study how the reliability of inverse model depends on a few basic parameters, as the combination of potential spacing and dipolar distance and, consequently, the number of measurements and of current dipoles, considering also how error affects inversion. The number of current dipole used is crucial, when using multichannel resistivity-meters, because it determines the overall acquisition time. A systematic comparison is presented between four 2D resistivity models and their images, obtained by the inversion of synthetic datasets relating to four different arrays: dipole-dipole (DD), pole-dipole (PD), Wenner-Schlumberger (WS) and multiple gradient (MG). For DD, PD…
Comparison of different sets of array configurations for multichannel 2D ERT acquisition
2017
Abstract Traditional electrode arrays such Wenner-Schlumberger or dipole-dipole are still widely used thanks to their well-known properties but the array configurations are generally not optimized for multi-channel resistivity measures. Synthetic datasets relating to four different arrays, dipole-dipole (DD), pole-dipole (PD), Wenner-Schlumberger (WS) and a modified version of multiple gradient (MG), have been made for a systematic comparison between 2D resistivity models and their inverted images. Different sets of array configurations generated from simple combinations of geometric parameters (potential dipole lengths and dipole separation factors) were tested with synthetic and field dat…
New Perspectives on Geophysics for Archaeology: A Special Issue
2018
This Special Issue hosts a selection of papers presented at the Third International Conference on Metrology for Archaeology and Cultural Heritage (Lecce, Italy, 23-25 October 2017), related to the new perspectives on geophysics for archaeology. In recent years, archaeological prospecting has seen major advances through a variety of remote sensing and computing technologies. Geophysical instrumentation continues to improve in sensitivity and acquisition speed, and new multi-sensor arrays, e.g., drawn by carts over land, now permit vast areas to be rapidly covered. On the other hand, the availability of highresolution remote sensing techniques provides multiscale and multi-temporal approaches…
Comparison between GPR measurements and ultrasonic tomography with different inversion algorithms: an application to the base of an ancient Egyptian …
2011
By late 2008 one of the most important pieces of the ‘Museo delle Antichit`a Egizie’ of Turin, the sculpture of the Pharaoh with god Amun, was planned to be one of the masterpieces of a travelling exhibition in Japan. The ‘Fondazione Museo delle Antichit`a Egizie di Torino’, who manages the museum, was concerned with the integrity of the base of the statue which actually presents visible signs of restoration dating back to the early 19th century. It was required to estimate the persistence of the visible fractures, to search for unknown ones and to provide information about the overall mechanical strength of the base. To tackle the first question a GPR reflection survey along three sides of…
Drones - New technologies for geophysics?
2015
Drones, also referred as Unmanned Aircraft Systems (UAS), Unmanned Aerial Vehicles (UAV) or Remotely Piloted Aircraft (RPA), are aircraft without pilot on board. USA is today the leading country in the field of UAS but recently, seven European countries have pledged to launch joint programs for drones, with the aim of producing the next generation of UAS before 2020. According to some studies on the potential market of UAS in Europe, the geoscience sector is definitely one of the most promising. In this paper, we bring a short description and classification of drones, according to their sized and shaped, with particular attention to the advantages and drawbacks of each type in reference to …
A la recerca del temple d’August a Tarragona: una experiència entre arqueologia i geofísica
2008
Aplicació de diferents tècniques de prospecció geofísica aplicades al subsòl de la Catedral de Tarragona: tomografia de resistivitat elèctrica (ERT), cartografia de conductivitat (EM) i radar de subsòl (GPR).
Evaluation of Artifacts and Misinterpretation in 2D Electrical Resistivity Tomography Caused by Three-Dimensional Resistive Structures of Regular or …
2023
Electrical resistivity tomography (ERT) is a well-known geophysical method applied to geological, hydrogeological and geoenvironmental research. To date, 2D ERT is still used much more than 3D ERT, thanks to its greater immediacy, survey speed and lower complexity in processing and inversion. However, the assumption of two-dimensionality of the underground structures can mean that the effects of 3D structures on the 2D ERT can sometimes lead to gross errors in interpretation. This work aims to evaluate these effects by testing synthetic and experimental models. Numerical simulations are performed starting from different resistivity models, and from the results, 2D data sets are derived to s…
A New Dissimilarity Measure for Clustering Seismic Signals
2011
Hypocenter and focal mechanism of an earthquake can be determined by the analysis of signals, named waveforms, related to the wave field produced and recorded by a seismic network. Assuming that waveform similarity implies the similarity of focal parameters, the analysis of those signals characterized by very similar shapes can be used to give important details about the physical phenomena which have generated an earthquake. Recent works have shown the effectiveness of cross-correlation and/or cross-spectral dissimilarities to identify clusters of seismic events. In this work we propose a new dissimilarity measure between seismic signals whose reliability has been tested on real seismic dat…
Exploring the spatial relationship between airborne-derived red and far-red sun-induced fluorescence and process-based GPP estimates in a forest ecos…
2019
International audience; Terrestrial gross primary productivity (GPP) plays an essential role in the global carbon cycle, but the quantification of the spatial and temporal variations in photosynthesis is still largely uncertain. Our work aimed to investigate the potential of remote sensing to provide new insights into plant photosynthesis at a fine spatial resolution. This goal was achieved by exploiting high-resolution images acquired with the FLuorescence EXplorer (FLEX) airborne demonstrator HyPlant. The sensor was flown over a mixed forest, and the images collected were elaborated to obtain two independent indicators of plant photosynthesis. First, maps of sun-induced chlorophyll fluore…
La metodologia MYG per eseguire tomografie elettriche 3D su oggetti che presentano una superficie di pregio artistico
2009
La tomografia elettrica di resistività è poco utilizzata nello studio delle murature di edifici di pregio artistico, malgrado le potenzialità in termini di risoluzione: attraverso indagini tridimensionali è infatti possibile ottenere tomografie di resistività 3D dettagliate e rappresentative. La necessità di inserire "chiodini" per immettere la corrente ne limita però l’applicabilità su superfici di pregio. Abbiamo superato questa limitazione sviluppando una metodologia (MYG) che riduce drasticamente rispetto ai metodi classici il numero degli elettrodi utilizzati per immettere la corrente (circa15 volte) ed il tempo di acquisizione (circa 50 volte), permettendo l'uso di elettrodi non invas…