Introduction. The Sabine Necropolis at Colle del Forno (700-300 B.C.) at Montelibretti, Rome is c... more Introduction. The Sabine Necropolis at Colle del Forno (700-300 B.C.) at Montelibretti, Rome is characterized by dromos chamber tombs, most of them unexplored till now. The tombs can be assimilated to cavities of a standard volume of some cubic meters; the entrance of the tombs is a corridor 6 m long with a 1 square meter section. The surficial geology of the area consists of a series of tuffs about 10 m thick overlying Pleistocene-Quaternary sandy-clayey sediments. A thin layer of top soil (20-30 cm) covers the tuff. The investigation of the Necropolis in the past decade has been performed by different geophysical methodologies: electrical, electromagnetic and magnetic methods have been widely adopted to investigate several chamber tombs (Piro et al, 2001). The aim of this paper is to analyze an integrated approach to the processing of magnetic survey data. The magnetic susceptibility contrast between topsoil, subsoil and rocks (topsoil is normally more magnetic than subsoil) permits to detect ditches, pits and other silted-up features that were excavated and then silted or back-filled with topsoil. Meanwhile back-filled areas produce positive anomalies, less magnetic material introduced into topsoil, including many kinds of masonry (for example, limestone walls) may produce negative anomalies of the order of some nanoteslas. The same behavior is related to the presence of cultural voids and tombs whose magnetic anomaly is generated by the lack of magnetic materials due to the cavities of the tombs. In the area a diffused magnetisation is manly due to the presence of top soil and tuff materials and high negative susceptibility contrasts can be expected because of the presence of the tombs. The magnetic survey was performed along a regular grid of 0.5 m x 0.5 m using a optical pumped Caesium-vapour magnetometer G858 (Geometrics), in the gradient configuration, on an area which is well known as far as the presence, size and position of tombs are concerned.
The geophysical prospection is generally considered as the attempt to locate structures of archae... more The geophysical prospection is generally considered as the attempt to locate structures of archaeological interest buried in the natural subsoil, but in many cases, when applied in urban centers, this attempt could fail due to the effect and disturbances caused by recent man-made structures in the subsoil, covering any signal related to possible archaeological structures. In the present paper the GPR surveys carried out in two urban archaeological sites in Roma, characterised by different targets and environmental conditions, are presented and discussed. The first site, a portion of Palatine Hill (archaeological center area of Roma) is characterized by natural soil on the surface and an overlapping of many archaeological structures in its volume. The second site, St. John Lateran Basilica (Roma), is characterized by artificial medium as road pavement, outside the basilica, and ancient buildings, below the actual basilica. The paper illustrates the two GPR surveys and the obtained results.
Previous reports (Haynes et al., 2020; 2021) have summarised progress on ROMETRANS, the ERCfunded... more Previous reports (Haynes et al., 2020; 2021) have summarised progress on ROMETRANS, the ERCfunded research project 'Rome Transformed: interdisciplinary analysis of political, military, and religious regenerations of the city's forgotten quarter C1-C8 CE' (https://cordis.europa.eu/project/id/835271). The period 2021-22, which falls halfway through the current five-year project, has been of the utmost importance to the overall fieldwork programme. To meet ROMETRANS's internal deadline for primary data capture (May 2022) while recovering time lost as a result of COVID restrictions required a tremendous effort from team members and our many generous collaborators, stakeholders and facilitators.
demonstrate how geophysical techniques have been used to find, restore and manage Italy's cultura... more demonstrate how geophysical techniques have been used to find, restore and manage Italy's cultural heritage.
The second part of this book is focused on the application of the different geophysical methodolo... more The second part of this book is focused on the application of the different geophysical methodologies - Geoelectrical, Ground Penetrating Radar and Electromagnetic - to Cultural Heritage, both in Italian and foreign sites. In order to highlight the various possible applications, the case studies, related to the most frequent diagnostic surveys, have been divided into main topic: Monuments, Historical Buildings, Urban Centres, Archaeological Parks, Preventive Archeology and Ancient viability.
Transforming multi-dimensional datasets, containing measurements of different physical parameters... more Transforming multi-dimensional datasets, containing measurements of different physical parameters recorded at the same location, into a single composite imagery is quite important and frequently used in geophysical analysis as well as other scientific disciplines. This study focuses on the application of several different integration approaches for archaeo-geophysical data with a purpose of achieving complementary and improved information about the buried archaeological target by generating a single data set from multiple geophysical methods. An extensive geophysical survey using ground penetrating radar (GPR) and differential magnetic methods was made in different parts of the Aizanoi archaeological site (Cavdarhisar, Kutahya, Turkey) to locate and enhance subsurface archaeological structures. However, in this article, the outputs of graphical, mathematical and statistical integration approaches, which are applied both on synthetic images and real field case data, are presented and discussed. Comparing these results and experimental applications, mathematical and statistical integration approaches provide more useful and practicable information than just the single distinct datasets from each geophysical parameter studied.
Near Surface Geoscience 2014 - 20th European Meeting of Environmental and Engineering Geophysics, 2014
ABSTRACT Non-destructive geophysical prospecting methods are increasingly used for the investigat... more ABSTRACT Non-destructive geophysical prospecting methods are increasingly used for the investigation of archaeological sites, where a detailed physical and geometrical reconstruction of structures is required prior to any excavation work. In this work the comparison between 3D inversions of ERT and vertical gradient of the total magnetic field (VGTMF) data, to delineate sharp discontinuities (boundary of cavities and fractures in the medium) in the Archaeological Test Site of Sabine Necropolis at Research Area of National Research Council of Rome (Montelibretti, Italy) are shown and discussed. While the VGTMF data inversion has been made minimizing an L-2 norm, the ERT data have been inverted minimizing an L-2 and an L-1 norm, obtaining different information and details. The results are then compared in the volume under the surveyed area: merits and shortcomings of the different techniques are pointed out and analyzed. Both ERT and VGTMF locate the tomb; VGTMF overestimates its barycentre depth and gives a smeared volume; ERT L-1 inversion gives a fine picture of the chamber, delineates the corridor and underestimates the resistivities; ERT L-2 inversion gives a broad image of the chamber, does not delineate the corridor but gives more appropriate resistivities.
The archaeological area of the Lateran in Rome lies immediately within the Aurelian Walls near th... more The archaeological area of the Lateran in Rome lies immediately within the Aurelian Walls near the gate of the Via Tusculana, under the Cathedral of St. John and the neighbouring buildings. It is an area of great historical importance. The domus of the first two centuries AD were superseded by the Castra Nova Equitum Singularium of Septimius Severus and later by the Constantinian basilica and the Lateran bishopric. The ‘Lateran Project’ was born from the collaboration between the Vatican Museums and the Universities of Florence, Newcastle and Northumbria, with the support of the British School of Rome and the collaboration of the Institute for Technologies Applied to Cultural Heritage of the Italian National Research Council (CNR). Up until now the major remains have only been published in brief preliminary notes, but the completion of a 3D survey by the Project allows a far more detailed and interesting reading.
ABSTRACT The area described in this article was ‘detected’ by the Laboratory for Landscape Archeo... more ABSTRACT The area described in this article was ‘detected’ by the Laboratory for Landscape Archeology and Remote Sensing,Universityof Sienaresearch teamduringaerialprospectionin spring 2005.Analysis of the aerial photographs allowed interpretation of the site as a triple-ditched enclosure.During subsequent field-walkingsurveyanumberofarchaeologicalartefactswerecollectedandmapped.Differential global positioning system (DGPS) survey confirmed the morphological pattern of the site, whichseemsto represent asurvivalofthe EarlyMedievalAgesettlement patternonthe coastalplain. The field-walking and DGPS surveys were followed by a programme of geophysical survey combining three different methods: differential magnetics (Overhauser probe), ground-penetrating radar (GPR) andAutomaticResistivity Profiler (ARP#, Geocarta).Finally, three sampleareaswere excavated,mainly to test the evidence collected previously.The excavation data ^ ditches, post-holes, domestic pottery, animalbones, andwallremains ^ support theinterpretationofthesiteasthefirstearth-and-timbercastle mound, ormotte, to be identified inTuscany
The ongoing off-site analysis of data captured in the field prior to early March 2020 and a range... more The ongoing off-site analysis of data captured in the field prior to early March 2020 and a range of equally essential work on archival sources and database development kept team members fully occupied. The British School at Rome team, led by Stephen Kay, used two Ground-Penetrating Radar (GPR) antennas, a 400 MHz and 200 MHz;the Consiglio Nazionale delle Ricerche team, led by Salvatore Piro, deployed GPR with a 70 MHz monostatic antenna and a GSSI 300/800 MHz dual-frequency digital antenna;and Geostudi Astier, led by Gianfranco Morelli, operated GPR with the IDS Stream multi-channel system, surveying between them a wide-ranging set of targets. Coordination of this work required not only the generous help of many key Roman stakeholders, more fully acknowledged below, but also a good understanding of the history of investigation at each location, something being further developed through archival research and data sharing with SITAR (https://www.archeositarproject.it/), the latter project led by Mirella Serlorenzi, and the Archivio Centrale dello Stato where, thanks to Mirco Modolo, we got the opportunity to work on the important documents that form part of Edoardo and Guglielmo Gatti's archive. [...]all three teams converged to take a combined approach to GPR and ERT.
By analysing the technical advantages and characteristics of imaging radar in cultural heritage, ... more By analysing the technical advantages and characteristics of imaging radar in cultural heritage, we provide new insights for the future development of cutting-edge Digital Heritage approaches through technical integration and interdisciplinary synergy.
We are going to present the focal-mechanism solution of Friuli earthquake occurred on May 6, 1976... more We are going to present the focal-mechanism solution of Friuli earthquake occurred on May 6, 1976, a~ it results from the analysis, on original seismograms, of the polarities of initial longitudinal waves obtained in 92 seismic stations. The polarities so obtained have been reported on the projection which represents the surface of the Earth and the solution has been drawn, directly, from the study of the resulting distribution, by establishing through Gr~fe's theory the two couples of forces considered as the sources of the seism at the focus. At last, a comparison has been carried out with the solution already obtained by other authors.
Geoscientific Instrumentation, Methods and Data Systems Discussions, 2016
This paper describes a noninvasive investigation conducted in two important churches, namely the ... more This paper describes a noninvasive investigation conducted in two important churches, namely the Cathedral of Santa Maria Assunta and the church Santa Croce, both placed in Gravina in Puglia (close to Bari, southern Italy). The church of Santa Croce, now deconsecrated, lies below the Cathedral. Therefore, indeed the two churches constitute a unique building body. Moreover, below the church of Santa Croce there are several crypts, only partially known. The prospecting was performed both with a pulsed commercial GPR system and with a prototypal reconfigurable stepped frequency system. The aim was twofold, namely to achieve some information about the monument and to test the prototypal system. The GPR measurements have been also integrated with an IRT investigation performed on part of the vaulted ceiling of the church of Santa Croce, in order to confirm or deny a possible interpretation of some GPR results.
Non-destructive geophysical prospecting methods are increasingly used for the investigation of ar... more Non-destructive geophysical prospecting methods are increasingly used for the investigation of archaeological sites, where a detailed physical and geometrical reconstruction of structures is required prior to any excavation work. In 1996, at the Archaeological Test Site of the Sabine Necropolis at Research Area of National Research Council of Rome (Montelibretti, Italy), a small area had been selected to test the integration of magnetic, ground-penetrating radar, and electrical resistivity tomography techniques. The magnetic data were acquired as the vertical gradient of the total magnetic field and were inverted by minimizing an L-2 norm. The ground-penetrating radar data were acquired as singleoffset measurements on a regular grid and processed to obtain time slices of reflection amplitude. The electrical resistivity tomography data were acquired with dipole–dipole array along parallel profiles in both east–west and north–south directions. In this work, we reprocessed the data collected in 1996 performing a three-dimensional inversion of electrical resistivity tomography data using ground-penetrating radar data and three-dimensional inversion results of the magnetic data. We inverted electrical resistivity tomography data according to L2 and L1 norm minimization. Both the mean apparent resistivity and different resistivity distributions derived from processed ground-penetrating radar and three-dimensional inversion of the vertical gradient of the total magnetic field data were used as a starting model. The results were then compared in the volume under the surveyed area: merits and shortcomings of the different techniques are pointed out and analyzed. From the results of the different applied techniques, it comes that both electrical resistivity tomography and vertical gradient of the total magnetic field locate the searched tomb as a volume, whereas ground-penetrating radar mainly identified the ceiling of the tomb. Vertical gradient of the total magnetic field data inversion obtained from minimization of the L2 norm properly locates both the chamber and the corridor but produces smeared overestimated volumes. Three-dimensional inversions of electrical resistivity tomography data with a priori information give an accurate picture of the chamber and delineates the corridor, even if the resistivity values are underestimated if compared with the expected resistivity of void. Results are compared with the archaeological findings as the area was unearthed and verified in 2001.
Introduction. The Sabine Necropolis at Colle del Forno (700-300 B.C.) at Montelibretti, Rome is c... more Introduction. The Sabine Necropolis at Colle del Forno (700-300 B.C.) at Montelibretti, Rome is characterized by dromos chamber tombs, most of them unexplored till now. The tombs can be assimilated to cavities of a standard volume of some cubic meters; the entrance of the tombs is a corridor 6 m long with a 1 square meter section. The surficial geology of the area consists of a series of tuffs about 10 m thick overlying Pleistocene-Quaternary sandy-clayey sediments. A thin layer of top soil (20-30 cm) covers the tuff. The investigation of the Necropolis in the past decade has been performed by different geophysical methodologies: electrical, electromagnetic and magnetic methods have been widely adopted to investigate several chamber tombs (Piro et al, 2001). The aim of this paper is to analyze an integrated approach to the processing of magnetic survey data. The magnetic susceptibility contrast between topsoil, subsoil and rocks (topsoil is normally more magnetic than subsoil) permits to detect ditches, pits and other silted-up features that were excavated and then silted or back-filled with topsoil. Meanwhile back-filled areas produce positive anomalies, less magnetic material introduced into topsoil, including many kinds of masonry (for example, limestone walls) may produce negative anomalies of the order of some nanoteslas. The same behavior is related to the presence of cultural voids and tombs whose magnetic anomaly is generated by the lack of magnetic materials due to the cavities of the tombs. In the area a diffused magnetisation is manly due to the presence of top soil and tuff materials and high negative susceptibility contrasts can be expected because of the presence of the tombs. The magnetic survey was performed along a regular grid of 0.5 m x 0.5 m using a optical pumped Caesium-vapour magnetometer G858 (Geometrics), in the gradient configuration, on an area which is well known as far as the presence, size and position of tombs are concerned.
The geophysical prospection is generally considered as the attempt to locate structures of archae... more The geophysical prospection is generally considered as the attempt to locate structures of archaeological interest buried in the natural subsoil, but in many cases, when applied in urban centers, this attempt could fail due to the effect and disturbances caused by recent man-made structures in the subsoil, covering any signal related to possible archaeological structures. In the present paper the GPR surveys carried out in two urban archaeological sites in Roma, characterised by different targets and environmental conditions, are presented and discussed. The first site, a portion of Palatine Hill (archaeological center area of Roma) is characterized by natural soil on the surface and an overlapping of many archaeological structures in its volume. The second site, St. John Lateran Basilica (Roma), is characterized by artificial medium as road pavement, outside the basilica, and ancient buildings, below the actual basilica. The paper illustrates the two GPR surveys and the obtained results.
Previous reports (Haynes et al., 2020; 2021) have summarised progress on ROMETRANS, the ERCfunded... more Previous reports (Haynes et al., 2020; 2021) have summarised progress on ROMETRANS, the ERCfunded research project 'Rome Transformed: interdisciplinary analysis of political, military, and religious regenerations of the city's forgotten quarter C1-C8 CE' (https://cordis.europa.eu/project/id/835271). The period 2021-22, which falls halfway through the current five-year project, has been of the utmost importance to the overall fieldwork programme. To meet ROMETRANS's internal deadline for primary data capture (May 2022) while recovering time lost as a result of COVID restrictions required a tremendous effort from team members and our many generous collaborators, stakeholders and facilitators.
demonstrate how geophysical techniques have been used to find, restore and manage Italy's cultura... more demonstrate how geophysical techniques have been used to find, restore and manage Italy's cultural heritage.
The second part of this book is focused on the application of the different geophysical methodolo... more The second part of this book is focused on the application of the different geophysical methodologies - Geoelectrical, Ground Penetrating Radar and Electromagnetic - to Cultural Heritage, both in Italian and foreign sites. In order to highlight the various possible applications, the case studies, related to the most frequent diagnostic surveys, have been divided into main topic: Monuments, Historical Buildings, Urban Centres, Archaeological Parks, Preventive Archeology and Ancient viability.
Transforming multi-dimensional datasets, containing measurements of different physical parameters... more Transforming multi-dimensional datasets, containing measurements of different physical parameters recorded at the same location, into a single composite imagery is quite important and frequently used in geophysical analysis as well as other scientific disciplines. This study focuses on the application of several different integration approaches for archaeo-geophysical data with a purpose of achieving complementary and improved information about the buried archaeological target by generating a single data set from multiple geophysical methods. An extensive geophysical survey using ground penetrating radar (GPR) and differential magnetic methods was made in different parts of the Aizanoi archaeological site (Cavdarhisar, Kutahya, Turkey) to locate and enhance subsurface archaeological structures. However, in this article, the outputs of graphical, mathematical and statistical integration approaches, which are applied both on synthetic images and real field case data, are presented and discussed. Comparing these results and experimental applications, mathematical and statistical integration approaches provide more useful and practicable information than just the single distinct datasets from each geophysical parameter studied.
Near Surface Geoscience 2014 - 20th European Meeting of Environmental and Engineering Geophysics, 2014
ABSTRACT Non-destructive geophysical prospecting methods are increasingly used for the investigat... more ABSTRACT Non-destructive geophysical prospecting methods are increasingly used for the investigation of archaeological sites, where a detailed physical and geometrical reconstruction of structures is required prior to any excavation work. In this work the comparison between 3D inversions of ERT and vertical gradient of the total magnetic field (VGTMF) data, to delineate sharp discontinuities (boundary of cavities and fractures in the medium) in the Archaeological Test Site of Sabine Necropolis at Research Area of National Research Council of Rome (Montelibretti, Italy) are shown and discussed. While the VGTMF data inversion has been made minimizing an L-2 norm, the ERT data have been inverted minimizing an L-2 and an L-1 norm, obtaining different information and details. The results are then compared in the volume under the surveyed area: merits and shortcomings of the different techniques are pointed out and analyzed. Both ERT and VGTMF locate the tomb; VGTMF overestimates its barycentre depth and gives a smeared volume; ERT L-1 inversion gives a fine picture of the chamber, delineates the corridor and underestimates the resistivities; ERT L-2 inversion gives a broad image of the chamber, does not delineate the corridor but gives more appropriate resistivities.
The archaeological area of the Lateran in Rome lies immediately within the Aurelian Walls near th... more The archaeological area of the Lateran in Rome lies immediately within the Aurelian Walls near the gate of the Via Tusculana, under the Cathedral of St. John and the neighbouring buildings. It is an area of great historical importance. The domus of the first two centuries AD were superseded by the Castra Nova Equitum Singularium of Septimius Severus and later by the Constantinian basilica and the Lateran bishopric. The ‘Lateran Project’ was born from the collaboration between the Vatican Museums and the Universities of Florence, Newcastle and Northumbria, with the support of the British School of Rome and the collaboration of the Institute for Technologies Applied to Cultural Heritage of the Italian National Research Council (CNR). Up until now the major remains have only been published in brief preliminary notes, but the completion of a 3D survey by the Project allows a far more detailed and interesting reading.
ABSTRACT The area described in this article was ‘detected’ by the Laboratory for Landscape Archeo... more ABSTRACT The area described in this article was ‘detected’ by the Laboratory for Landscape Archeology and Remote Sensing,Universityof Sienaresearch teamduringaerialprospectionin spring 2005.Analysis of the aerial photographs allowed interpretation of the site as a triple-ditched enclosure.During subsequent field-walkingsurveyanumberofarchaeologicalartefactswerecollectedandmapped.Differential global positioning system (DGPS) survey confirmed the morphological pattern of the site, whichseemsto represent asurvivalofthe EarlyMedievalAgesettlement patternonthe coastalplain. The field-walking and DGPS surveys were followed by a programme of geophysical survey combining three different methods: differential magnetics (Overhauser probe), ground-penetrating radar (GPR) andAutomaticResistivity Profiler (ARP#, Geocarta).Finally, three sampleareaswere excavated,mainly to test the evidence collected previously.The excavation data ^ ditches, post-holes, domestic pottery, animalbones, andwallremains ^ support theinterpretationofthesiteasthefirstearth-and-timbercastle mound, ormotte, to be identified inTuscany
The ongoing off-site analysis of data captured in the field prior to early March 2020 and a range... more The ongoing off-site analysis of data captured in the field prior to early March 2020 and a range of equally essential work on archival sources and database development kept team members fully occupied. The British School at Rome team, led by Stephen Kay, used two Ground-Penetrating Radar (GPR) antennas, a 400 MHz and 200 MHz;the Consiglio Nazionale delle Ricerche team, led by Salvatore Piro, deployed GPR with a 70 MHz monostatic antenna and a GSSI 300/800 MHz dual-frequency digital antenna;and Geostudi Astier, led by Gianfranco Morelli, operated GPR with the IDS Stream multi-channel system, surveying between them a wide-ranging set of targets. Coordination of this work required not only the generous help of many key Roman stakeholders, more fully acknowledged below, but also a good understanding of the history of investigation at each location, something being further developed through archival research and data sharing with SITAR (https://www.archeositarproject.it/), the latter project led by Mirella Serlorenzi, and the Archivio Centrale dello Stato where, thanks to Mirco Modolo, we got the opportunity to work on the important documents that form part of Edoardo and Guglielmo Gatti's archive. [...]all three teams converged to take a combined approach to GPR and ERT.
By analysing the technical advantages and characteristics of imaging radar in cultural heritage, ... more By analysing the technical advantages and characteristics of imaging radar in cultural heritage, we provide new insights for the future development of cutting-edge Digital Heritage approaches through technical integration and interdisciplinary synergy.
We are going to present the focal-mechanism solution of Friuli earthquake occurred on May 6, 1976... more We are going to present the focal-mechanism solution of Friuli earthquake occurred on May 6, 1976, a~ it results from the analysis, on original seismograms, of the polarities of initial longitudinal waves obtained in 92 seismic stations. The polarities so obtained have been reported on the projection which represents the surface of the Earth and the solution has been drawn, directly, from the study of the resulting distribution, by establishing through Gr~fe's theory the two couples of forces considered as the sources of the seism at the focus. At last, a comparison has been carried out with the solution already obtained by other authors.
Geoscientific Instrumentation, Methods and Data Systems Discussions, 2016
This paper describes a noninvasive investigation conducted in two important churches, namely the ... more This paper describes a noninvasive investigation conducted in two important churches, namely the Cathedral of Santa Maria Assunta and the church Santa Croce, both placed in Gravina in Puglia (close to Bari, southern Italy). The church of Santa Croce, now deconsecrated, lies below the Cathedral. Therefore, indeed the two churches constitute a unique building body. Moreover, below the church of Santa Croce there are several crypts, only partially known. The prospecting was performed both with a pulsed commercial GPR system and with a prototypal reconfigurable stepped frequency system. The aim was twofold, namely to achieve some information about the monument and to test the prototypal system. The GPR measurements have been also integrated with an IRT investigation performed on part of the vaulted ceiling of the church of Santa Croce, in order to confirm or deny a possible interpretation of some GPR results.
Non-destructive geophysical prospecting methods are increasingly used for the investigation of ar... more Non-destructive geophysical prospecting methods are increasingly used for the investigation of archaeological sites, where a detailed physical and geometrical reconstruction of structures is required prior to any excavation work. In 1996, at the Archaeological Test Site of the Sabine Necropolis at Research Area of National Research Council of Rome (Montelibretti, Italy), a small area had been selected to test the integration of magnetic, ground-penetrating radar, and electrical resistivity tomography techniques. The magnetic data were acquired as the vertical gradient of the total magnetic field and were inverted by minimizing an L-2 norm. The ground-penetrating radar data were acquired as singleoffset measurements on a regular grid and processed to obtain time slices of reflection amplitude. The electrical resistivity tomography data were acquired with dipole–dipole array along parallel profiles in both east–west and north–south directions. In this work, we reprocessed the data collected in 1996 performing a three-dimensional inversion of electrical resistivity tomography data using ground-penetrating radar data and three-dimensional inversion results of the magnetic data. We inverted electrical resistivity tomography data according to L2 and L1 norm minimization. Both the mean apparent resistivity and different resistivity distributions derived from processed ground-penetrating radar and three-dimensional inversion of the vertical gradient of the total magnetic field data were used as a starting model. The results were then compared in the volume under the surveyed area: merits and shortcomings of the different techniques are pointed out and analyzed. From the results of the different applied techniques, it comes that both electrical resistivity tomography and vertical gradient of the total magnetic field locate the searched tomb as a volume, whereas ground-penetrating radar mainly identified the ceiling of the tomb. Vertical gradient of the total magnetic field data inversion obtained from minimization of the L2 norm properly locates both the chamber and the corridor but produces smeared overestimated volumes. Three-dimensional inversions of electrical resistivity tomography data with a priori information give an accurate picture of the chamber and delineates the corridor, even if the resistivity values are underestimated if compared with the expected resistivity of void. Results are compared with the archaeological findings as the area was unearthed and verified in 2001.
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Papers by Salvatore Piro