3D laser scanner

Dense point clouds acquired from Terrestrial Laser Scanners (TLS) have proved to be effective for structural deformation assessment. In the last decade, many researchers have defined methodology and workflow in order to compare different point clouds, with respect to each other or to a known model, assessing the potentialities and limits of this technique. Currently, dense point clouds can be obtained by Close-Range Photogrammetry (CRP) based on a Structure from Motion (SfM) algorithm. This work reports on a comparison between the TLS technique and the Close-Range Photogrammetry using the Structure from Motion algorithm. The analysis of two Reinforced Concrete (RC) beams tested under four-points bending loading is presented. In order to measure displacement distributions, point clouds at different beam loading states were acquired and compared. A description of the instrumentation used and the experimental environment, along with a comprehensive report on the calculations and results obtained is reported. Two kinds of point clouds comparison were investigated: Mesh to mesh and modeling with geometric primitives. The comparison between the mesh to mesh (m2m) approach and the modeling (m) one showed that the latter leads to significantly better results for both TLS and CRP. The results obtained with the TLS for both m2m and m methodologies present a Root Mean Square (RMS) levels below 1 mm, while the CRP method yields to an RMS level of a few millimeters for m2m, and of 1 mm for m.

Mediterranean silo features Underground architecture Ground penetrating radar 3D laser scanner model a b s t r a c t Underground space has widely been used through history, provided either by natural or by dug cavities that were used as storage for farming production. In particular, cereals have constantly been present in the Mediterranean cultures. Their preservation was crucial in the Mediterranean grain trade for local and urban growth. The main goal of this multidisciplinary study is to analyse the typological and architectural characteristics of underground Mediterranean granary structures. It also discusses the excavation process for building a silo, focusing in a study of the Valencian silos at the Spanish Mediterranean shore. The Valencian silo-yard was essential for the socioeconomic city development in the 16th century. This is the first research performed on this subterranean ensemble, by searching through historical documents and using a non-destructive technique (NDT) as Ground Penetrating Radar (SIR-3000, GSSI) with 100 MHz and 400 MHz antennae. The composition soil was obtained for hydrogeological characteristics by geotechnical tests. Besides, laser scanner and GPS surveys were carried out for mapping the silo-yard in detail. Since the Valencian silos are a relevant example of subterranean engineering storage, we were able to carry out a comparative study of significant Mediterranean silos (from Algeria, Italy, Jordan, Malta and Turkey) by reviewing documentation. As a result, these underground spaces share numerous features, as type of terrain, excavation process, geographic location, morphology, dimensions, sealing system, usage, etc. These similar features illustrate that a subterranean grain storage stereotype is present in the Mediterranean region heritage.

We propose an automated method to recover the full calibration parameters between a 3D range sensor and a monocular camera system. Our method is not only accurate and fully automated, but also relies on a simple calibration target consisting of a single circle. This allows the algorithm to be suitable for applications requiring in-situ calibration. We demonstrate the effectiveness of the algorithm on a cameralidar system and show results on 3D mapping tasks.

We present a review of the Tomb of the Elephant at the Roman Necropolis of Carmona (Sevilla) made under the methodological principles of Building Archaeology and Archaeoastronomy. The results show that the building had several phases of use and was built to be a mithraeum as indicate its form and symbolism derived from the archaeoastronomical analysis of the window solar orientation.

This paper examines how surveying and monitoring improve our knowledge about ancient buildings, allow the interpretation of their structural response and help in the search for the best solutions for their conservation. The case study of Palazzo del Capitano in Mantua (Italy) is analyzed. In particular, the attention is focused on the use of a Terrestrial Laser Scanner (TLS) for surveying and monitoring too, considering that the building structural control has been performed in combination with other traditional topographic techniques such as geometric leveling and topographic networks for 3D control based on measurements through total stations. The study of TLS monitoring has been tested only in the last decade and it is an innovative method for the detection of displacements of particular surfaces. Till now the research has focused only on the use of TLS monitoring to control large structures and in particular landscape situations; thus its use for a civil construction and historical buildings is a new field of investigation. Despite the fact technological development and new methodologies seem offer new future potential for the analysis of ancient buildings, currently there are still important limits for the application of the investigated surveying and monitoring techniques.

Rock mass classification systems are widely used tools for assessing the stability of rock slopes. Their  calculation requires the prior quantification of several parameters during conventional fieldwork campaigns, such as the orientation of the discontinuity sets, the main properties of the existing discontinuities and the geo-mechanical characterisation of the intact rock mass, which can be time-consuming and an often risky task. Conversely, the use of relatively new remote sensing data for modelling the rock mass surface by means of 3D point clouds is changing the current investigation strategies in different rock slope engineering applications.  In this paper,  the main practical issues affecting the application of Slope Mass Rating (SMR) for the characterization of rock slopes from 3D point clouds are reviewed, using three case studies from an end-user point of view. To this end, the SMR adjustment factors, which was calculated from different sources of information and processed, using the different softwares, are compared with those calculated using conventional fieldwork data. In the presented analysis, special attention is paid to the differences between the SMR indexes derived from the 3D point cloud and conventional field work approaches, the main factors that determine  the quality of the data and some recognized practical issues. Finally, the reliability of Slope Mass Rating for the characterization of rocky slopes is highlighted.

We tested three surface scanning systems: the low cost NextEngine laser scanner, the white light Fringe Projection Breuckmann Smartscan and the white light Fringe Projection Steinbichler COMET V 4M. We evaluate the potential of such systems for digitalizing original anthropological specimens and compare it with a "nominal" 3D model derived from µCT or CT data. Our results show that surface scanning of teeth is generally problematic even for high end systems. Even though studies of the occlusal surface are possible with high end systems, high resolution µCT still has to be considered the best choice for scientific studies dealing with details of the occlusal surface. However, for general digitalization purposes and recording of dimensions even the NextEngine system is suitable. In our tests, Breuckmann Smartscan produced the best models with the lowest deviation compared to the nominal µCTmodel. The Steinbichler is the fastest system but the quality of the resulting models is slightly lower. NextEngine produces a clearly lower quality than the tested high end systems but if one considers the different price margins of the systems, the proportionally good data provided by NextEngine is remarkable. In the case of bones with a simple geometric structure, this low cost scanner can compete easily with 3D models derived from medical CT for gross morphometric studies.

On 24 October 2015, following a period of heavy rainfall, a landslide occurred in the Calatabiano Municipality (Sicily Island, Southern Italy), causing the rupture of a water pipeline supplying water to the city of Messina. Following this event, approximately 250,000 inhabitants of the city suffered critical water shortages for several days. Consequently, on 6 November 2015, a state of emergency was declared (O.C.D.P. 295/2015) by the National Italian Department of Civil Protection (DPC). During the emergency management phase, a provisional bypass , consisting of three 350-m long pipes passing through the landslide area, was constructed to restore water to the city. Furthermore, on 11 November 2015, a landslide remote-sensing monitoring system was installed with the following purposes: (i) analyse the landslide geomorphological and kinematic features in order to assess the residual landslide risk and (ii) support the early warning procedures needed to ensure the safety of the personnel involved in the bypass construction and the landslide stabilization works. The monitoring system was based on the combined use of Ground-Based Interferometric Synthetic Aperture Radar (GB-InSAR) and terrestrial laser scanning (TLS). In this work, the preliminary results of the monitoring activities and a remote 3D map of the landslide area are presented.

Terrestrial laser scanners are sophisticated instruments that operate much like high-speed total stations.  It has previously been shown that  unmodelled systematic errors can exist in modern terrestrial laser scanners that deteriorate their geometric measurement precision and accuracy. Typically, signalised targets are used in point-based self-calibrations to
identify and model the systematic errors. Although this method has proven its effectiveness, a large quantity of signalised targets is required and is therefore labour-intensive  and limits its practicality.  In recent years, feature-based self-calibration of aerial, mobile terrestrial, and static terrestrial laser scanning systems has been demonstrated.  In this paper, the commonalities and differences between point-based and plane-based self-calibration (in terms of model identification and parameter correlation) are explored.  The results of  this
research indicate that much of the knowledge from point-based self-calibration can be directly transferred to plane-based calibration and that the two calibration approaches are
nearly equivalent.  New network configurations, such as the inclusion of tilted scans, were also studied and prove to be an effective means for strengthening the self-calibration solution, and improved recoverability of the horizontal collimation axis error for hybrid scanners, which has always posed a challenge in the past.

Despite being a well-known monument, the Roman amphitheatre of Tarragona, which is included in the UNESCO World Heritage List, was only fully studied in the late 1980s. The study was therefore subject to the archaeological research limitations and specific characteristics of that time, as can be seen in the quality of the site's planimetry. The general planimetry was basically available for relevant sections at a scale of 1:100 with sufficient accuracy. However, according to current scientific parameters, this planimetry is clearly inadequate, and cannot be used rigorously to obtain comprehensive architectural knowledge. The technical limitations of the time, and the innate difficulties presented by the monument, meant that only a few sections were obtained, specifically two, with a low level of detail. This has led to misinterpretations, and consequently to dubious or erroneous conclusions. Therefore, the need for complete metric documentation is evident, as this will enable us to correctly analyse the monument. We have obtained metric documentation by carrying out a topographic survey using digital photogrammetry, which provides us with more information than merely measurements. We can use the three-dimensional model that was generated to analyse the sections of the stands and draw conclusions about their geometry.

This paper presents a non-contact 3D environments mapping technique using mobile robots with different perception devices such as stereo camera, structural light camera or custom made 3D laser scanner. The custom developed non-contact scanning device is suitable for making building surveillance both in small and large scales. These measurements can be further used for urban region planning as well as for navigation purposes for autonomous agents such as mobile vehicles.. The large maps can be built from successive scan merging in an iterative manner. For such an approach is essential the initial matching between two measurements, which in our proposed method was performed using special extracted features from the measured data sets. The registered maps can be further used for perceptual purposes, including object segmentation or planning maps for the mobile agents. For both types of applications, there are given experimental results obtained from the proposed registration and segmentation algorithms.

Manufacturers often express the performance of a 3D imaging device in various non-uniform ways for the lack of internationally recognized standard requirements for metrological parameters able to identify the capability of capturing a real scene. For this reason several national and international organizations in the last ten years have been developing protocols for verifying such performance. Ranging from VDI/VDE 2634, published by the Association of German Engineers and oriented to the world of mechanical 3D measurements (triangulation-based devices), to the ASTM technical committee E57, working also on laser systems based on direct range detection (TOF, Phase Shift, FM-CW, flash LADAR), this paper shows the state of the art about the characterization of active range devices, with special emphasis on measurement uncertainty, accuracy and resolution. Most of these protocols are based on special objects whose shape and size are certified with a known level of accuracy. By capturing the 3D shape of such objects with a range device, a comparison between the measured points and the theoretical shape they should represent is possible. The actual deviations can be directly analyzed or some derived parameters can be obtained (e.g. angles between planes, distances between barycenters of spheres rigidly connected, frequency domain parameters, etc.). This paper shows theoretical aspects and experimental results of some novel characterization methods applied to different categories of active 3D imaging devices based on both principles of triangulation and direct range detection.

Population growth frequently causes expansion of urban populations and associated transportation facilities onto formerly uninhabited slopes, where naturally occurring and constructed rock faces present potential hazards from rock fall and rock face instability. Rock fall management and mitigation programs are widely used to ensure public safety, to provide efficient rock face maintenance, and to proactively address potential rock fall hazards. These programs require comprehensive geologic characterization of individual rock slopes. New ways of collecting data are urgently required to accelerate field data acquisition, reduce identification difficulties, eliminate safety constraints, and remove human bias and subjectivity in the data. Exposed rock surfaces can be scanned quickly and accurately using a ground-based laser scanner, resulting in a collection of millions of discrete points each having a 3D value relative to the scanner's position. These "point clouds" have high spatial resolution, with adjacent points often only a centimeter or two apart. Relatively small surface features and discontinuities are readily identified. Algorithms have been developed to support semi-automated processes for orienting the point cloud, creating a polygonal surface model from the point cloud, determining rock discontinuity information, and defining block size distributions.

Our contribution is based on a research aimed to a “quick” resolution of an integrated problem oriented towards the self-localization and perimetration through mobile devices. The adopted methodology is applied on a real case study by using the following surveying tools: a kinematic Global Positioning System (GPS) and a Laser Scanner supporting a “mobile platform”. A GPS receiver provided by Leica Geosystem and a two-dimensional Laser Scanner provided by the Automation and Control Laboratory of the University “Mediteranea” of Reggio Calabria were positioned on an experimental mobile system specifically designed to simulate the behaviour of a future and fully automated platform. The research is aimed to conduct the traditional land surveying through a Laser Scanner alongside with GPS receivers in a three dimensional centimetric resolution within one single system of reference made up of individual scans operated by a “Stop-and-Go “ device.

Game engines can be regarded as powerful tools in the Cultural Heritage domain, not just as dissemination tools, but for managing the urban context in real time. This case-study is based on the ongoing project of Pietrabuona Castle (Pescia, Italy). It is an interesting example of a stratified historical centre, the conservation and promotion of which might benefit from using a new, integrated survey and alphanumeric data management tool. The method used to survey this medieval fortification had to provide both local institutions and researchers with an interactive tool encompassing several features of Cultural Heritage: from technical (decay, maintenance, environmental risks, etc.) to cultural (urban standard, historical understanding, immaterial features). Due to the cross-disciplinary nature of the ongoing project, we decided to share some major points of our investigation with the scientific community, in particular those concerning our procedure: the opportunity to use interactive applications to display themes of urban settlements as 3D models, based on a survey by laser scanner.

Laser scanner has become widely used nowadays
for several applications in civil engineering. An advantage
of laser scanner as compared to other geodetic instruments
is its capability of collecting hundreds or even
thousands of point per second. Terrestrial laser scanner
allows acquiring easy and fast complex geometric data
from building, machines, objects, etc. Several experimental
and field tests are required to investigate the quality
and accuracy of scanner points cloud and the 3D geometric
models derived from laser scanner. So this paper investigates
the precision of creation three dimensional structural
model resulted from terrestrial laser scanner observations.
The paper also presented the ability to create 3D
model by structural faces depending on the plane equation
for each face resulted from coordinates of several observed
points cover this face using reflector less total station
observations. Precision comparison for the quality of
3D models created from laser scanner observations and
structure faces is also presented.The results of the practical
measurements, calculations and analysis of results are
presented

Reasoning from information extraction given by point cloud data mining allows contextual adaptation and fast decision making. However, to achieve this perceptive level, a point cloud must be semantically rich, retaining relevant information for the end user. This paper presents an automatic knowledge-based method for pre-processing multi-sensory data and classifying a hybrid point cloud from both terrestrial laser scanning and dense image matching. Using 18 features including sensor's biased data, each tessera in the high-density point cloud from the 3D captured complex mosaics of Germigny-des-prés (France) is segmented via a colour multi-scale abstraction-based featuring extracting connectivity. A 2D surface and outline polygon of each tessera is generated by a RANSAC plane extraction and convex hull fitting. Knowledge is then used to classify every tesserae based on their size, surface, shape, material properties and their neighbour's class. The detection and semantic enrichment method shows promising results of 94% correct semantization, a first step toward the creation of an archaeological smart point cloud.

Creating digital replicas of unique biological findings or archeological artifacts has become a desirable task, which enables to spare original integrity and enhance accessibility of valuable objects to a wide range of experts as well as public. In recent years, specialized scanning devices have been challenged by performance of photogrammetry software tools capable of processing unstructured image sets and providing three-dimensional digital models in return. Simplicity, portability and affordability predetermine photogrammetry to be the method of choice if three-dimensional documentation is to be conducted at remote facilities and outdoor locations. The present paper tests technical limitations of two 3D documentation techniques – close range photogrammetry carried out in Agisoft PhotoScan software and laser scanning conducted with MicroScribe/MicroScan scanning unit while documenting pelvic bones and sacra from the Upper Paleolithic triple burial of Dolní Věstonice, Czech Republic. For photogrammetry, two different approaches to generate closed textured 3D models were confronted – alignment of partial polygonal meshes and joint processing of multiple image sets. Our results showed that photogrammetry provided high-resolution 3D models appended by photorealistic texture. In terms of depicted details, the photogrammetry-generated models were comparable to those of laser scanning. However, the robust performance of the employed algorithm was achieved at the expense of extensive time and labor demands, which for many experts may be difficult to justify. In conclusion, photogrammetry should be considered a suitable substitute for surface scanners only if conducted for occasional and/or out-of-lab documentation tasks. KEY WORDS: Photogrammetry ‒ Laser scanning ‒ Three-dimensional documentation ‒ Skeletal remains ‒ Paleoanthropology ‒ Dolní Věstonice ANTHROPOLOGIE

A workflow is proposed for Cultural Heritage applications in which the fusion of 3D and 2D visual data is required. Using data acquired by cheap, standard devices, like a 3D scanner having a low quality 2D camera in it, and a high resolution DSLR camera, one can produce high quality color calibrated 3D model for documenting purpose. The proposed processing workflow combines a novel region based calibration method with an ICP alignment used for refining the results. It works on 3D data, that do not necessarily contain intensity information in them, and 2D images of a calibrated camera. These can be acquired with commercial 3D scanners and color cameras without any special constraint. In contrast with the typical solutions, the proposed method is not using any calibration patterns or markers. The efficiency and robustness of the proposed calibration method has been confirmed on both synthetic and real data.

The article reports about a multi-resolution approach developed for the 3D modeling of the entire Roman Forum in Pompei, Italy. The archaeological area, approximately 150 x 80 m, contains more than 350 finds spread all over the forum as well as larger mural structures of previous buildings and temples. The interdisciplinary 3D modeling work consists of a multi-scale image- and range-based digital documentation method developed to fulfill all the surveying and archaeological needs and exploit all the potentialities of the actual 3D modeling techniques. Data’s resolution spans from few decimeters down to few millimeters. The employed surveying methodologies have pros and cons which will be addressed and discussed. The preliminary results of the integration of the different 3D data in seamlessly textured 3D model, will be presented.

Curating boats can be difficult. They are complex structures, often demanding to conserve whether in or out of the water; they are usually large, difficult to move on land, and demanding of gallery space. Communicating life on board to a visiting public in the terra firma context of a museum can be difficult. Boats in their native environment are inherently dynamic artifacts. In a museum they can be static and divorced from the maritime context that might inspire engagement. New technologies offer new approaches to these problems. 3D laser scanning and digital modeling offers museums a multifaceted means of recording, monitoring, studying and communicating watercraft in their care. In this paper we describe the application of 3D laser scanning and subsequent digital modeling. Laser scans were further developed using computer-generated imagery (CGI) modeling techniques to produce photorealistic 3D digital models for development into interactive, media-based museum displays. The scans were also used to generate 2D naval lines and orthographic drawings as a lasting curatorial record of the dhows held by the National Museum of Qatar.

The core of the paper is focused on the experimental characterization of four different 3D laser scanners based on Time of Flight principle, through the extraction of resolution, accuracy and uncertainty parameters from specifically designed 3D test objects. The testing process leads to four results: z-uncertainty, xy-resolution z-resolution and z-accuracy. The first is obtained by the evaluation of random residuals from the 3D capture of a planar target, the second from the scanner response to an abrupt z-jump, and the last two from direct evaluation of the image extracted by different geometric features progressively closer each other. The aim of this research is to suggest a low cost characterization process, mainly based on calibrated test object easy to duplicate, that allow an objective and reliable comparison between 3D TOF scanner performances.

The increasing importance of virtual techniques in archaeology and anthropology puts the question of adequate hardware and software applications for a digitalization of collections for museums and institutions into the focus. Especially the market for mobile 3D scanning developed rapidly during the last years and provides a range of different models suitable for scientific purposes today. As the requirements for archaeological and anthropological applications are very high and differentiated -due to the, in some cases very complex surface morphologies of the objects and the different textures from shiny obsidian to porous bone -the decision for a scanner model is often complicated. The Neanderthal Museum and the Royal Belgian Institute of Sciences have been testing six different surface scanner from four companies during the last months concerning their suitability for archaeological and anthropological objects. Quality of the 3D models was rated by the visibility and exactness of standard attributes used for classification of the object type in archaeology or anthropology. Results are presented here. Generally, all types of archaeological and anthropological objects can be digitalized with surface scanner. If a high end or a low budget model should be used depends on the texture of the object and the intended purpose.

Point clouds are objects with an unquestionable geometric value. However, the development of certain working methodologies allows the extraction of information that goes beyond the metric, allowing a semantic analysis of the documented object. In this work, we present one of these methodologies that allows, with the sole modification of the visualization of the point clouds, to highlighting the elements of semantic value in the scanned architectural object.

The 3D modeling techniques applied on laser scanner data are becoming increasingly relevant in the cultural heritage dissemination field. However the need for a satisfactory similarity between model and real object collides with the need to preserve the original accuracy of the measurement of the former than the latter. The analysis of the Compañía de Jesús facade has tried to cope this duality using the power of reverse modeling and texturing, the latter is really important due to the function of the photographic images into accurate description of materials and colours, as well as in the creation of 3D models using UV mapping tools, which are a very advanced field of the computer graphic software.

The basilica of St. Silvestro was erected in 1907 on the foundations of two ancient rooms surrounded by several mausolea, its excavation took place from 1890 to 1906. The presence of some venerated burials led to the realization of a second building thought to be an indoor cemetery. Today the burials and the fragments of sarcophagi have been moved in the museum. Among the choices of project an integrated digital survey both 3D laser scanner that photogrammetry have been used. The survey had to deal with the complex characteristics of the pieces of sculptures and the difficulties linked to the light subsurface dispersion of the marble. To give a better access to monument, an architectural project and the digital technology tried to enhance the real with a digital layer.

In this work a detailed TLS survey was carried out in summer 2012, in the Conero Regional Park (Marche, province of Ancona), along the "spiaggia San Michele" and "spiaggia Sassi Neri". These areas present several sections affected by erosion, rock falls and slope failures. They also belong to a very prestigious place for tourism during the summer season; therefore, deriving a risk map for these areas is really useful. Thanks to the TLS survey, it was possible to obtain a centimetre resolution DTM covering a reach of about 1.5 km of the coast. This high resolution DTM was used to derive some primary topographic attributes that allowed to arrange a preliminary discussion about the likely unstable areas. These topographic information and results will also serve as the reference point for future yearly TLS surveys, which will absolutely help in recognizing any micro changes and slope failures, improving the risk maps.

The paper underlines the importance to apply a methodology that integrates the Building Information Modeling (BIM), Work Breakdown Structure (WBS) and the Laser Scanner tool in conservation and reuse projects. As it is known, the laser scanner technology provides a survey of the building object which is more accurate rather than that carried out using traditional methodologies. Today most existing buildings present their attributes in a dispersed way, stored and collected in paper documents, in sheets of equipment information, in file folders of maintenance records. In some cases, it is difficult to find updated technical documentation and the research of reliable data can be a cost and time-consuming process. Therefore, this new survey technology, embedded with BIM systems represents a valid tool to obtain a coherent picture of the building state. The following case consists in the conservation and reuse project of Milan Lyric Theatre, started in 2013 from the collaboration between the Milan Polytechnic and the Municipality. This project first attempts to integrate these new techniques which are already professional standards in many other countries such as the US, Norway, Finland, England and so on. Concerning the methodology, the choice has been to use BIM software for the structured analysis of the project, with the aim to define a single code of communication to develop a coherent documentation according to rules in a consistent manner and in tight schedules. This process provides the definition of an effective and efficient operating method that can be applied to other projects.

The “Fortezza Vecchia” (Old Fortress) in Livorno resumes many features of the fortified architecture realized in the Mediterranean in the Modern age, at the same time it has a significant stratification, with the clear sign of a continuous reuse, expansion and adaptation across time. Built from the XIV century it received main reconstructions and extension works from the XVI to the XX century. In early 2017 a complete digital survey (still ongoing at the time of this writing) has been started under the collaboration of Autorità Portuale di Livorno (Livorno Port Autority), Area3D S.l.r. and Dipartimento di Architettura, Firenze. The survey work has been planned using two 3D laser scanners with the implementation of topographical survey, terrestrial and areal (IUAV) photogrammetry. The paper proposed here will present the state of development of the data treatment and the specific methodology used to document such an important and large fortress.

On October 24th 2015, following a period of heavy rainfall, a landslide triggered in the Calatabiano Municipality (Sicily Island, Southern Italy) causing the rupture of a water pipeline transect of the aqueduct supplying water to the city of Messina. This event, caused critical water shortages for several days to a large part of the city inhabitants. In order to restore the city water supplies, a provisional bypass , consisting of three 350 m long pipes passing through the landslide area, was carried out. On November 11th 2015, a landslide monitoring system was installed, based on the combined use of advanced remote sensing techniques such as Ground-Based Interferometric Synthetic Aperture Radar (GB-InSAR), Terrestrial Laser Scanning (TLS) and Infrared Thermography (IRT). The installed monitoring system allowed to: (i) analyze the landslide geomorphological and kinematic features in order to assess the landslide residual risk; (ii) support the early warning procedures needed to ensure the safety of the personnel involved in the bypass realization and the landslide stabilization works. In this work, the preliminary results of the monitoring activities and a 3-D mapping of the landslide area are presented.

The development of new measurement techniques is changing the process of documentation and
assessment of built heritage. An accurate planimetric basis is essential for the constructive
evaluation of a building. This paper presents the methodology used in the geometric
assessment of Gothic vaults in the Cathedral of Tortosa (Spain). The use of a Terrestrial Laser
Scanner allows the assessment of the vaulting to a level of detail that has never been possible
to achieve previously. The accurate identification of geometric deviations in the masonry can
be combined with the information from primary sources, revealing new information about the
construction process of the apse.

The present study discusses the restoration of the sixteenth-century painting made on wood, which depicts the Adoration of the Shepherds with a holy bishop, by an unknown author, currently preserved in the deposits of Galleria Regionale della Sicilia di Palazzo Abatellis, in Palermo. Throughout the restoration, a graphic and photographic documentation phase and one of research were addressed, being supported by the experience of different personalities in the historical, artistical and technical-scientific-fields, which allowed to obtain useful information on the work being studied. An in-depth archival research permitted to reconstruct the history of the painting from its original location, at the museum of the Benedictine Abbey of San Martino delle Scale, until the current position. The art-historical analysis, together with the executive techniques one, has allowed us to confirm the creation of the work in the last decades of the sixteenth century. The painter seems, indeed, respects the iconographic choices that spread in Sicily in the period after the Catholic-Reformation, thanks to the diffusion of engravings, which would appear to affect on the concise setting and on the painting bluntly graphical style. The comparison of some stylistic details with other known and operating artists in Palermo in the second half of the sixteenth-century, as well as the use of a mixed technique sustain this thesis. The restoration has aimed, therefore, at reestablishment of a good reading of the work, starting from the consolidation operation, whose purpose was to preserve the integrity of all the original constituent layers and removing, however, the previous interventions which disfigured the image. The intention to reinstate the value and completeness of the frame, deprived of an angular decorative element, has stimulated the search for alternative methods and to the casts, however, if is not prohibited, now is limited by the current law. "The function of the frame is defined [...] as a spatial connection" 1 says Cesare Brandi, first "space between the physical environment that surrounds the viewer and the space of the painting," 2 and secondly "between this space and the spatiality of the wall on which the painting is placed." 3 In the case we examined, it was decided to operate in order to find a solution respecting the principles of recognition, reversibility and compatibility, and restore this "spatial connection", putting reverse engineering and materials used in the field of 3D printing at the service of our study. On the latter it has carried out a test phase, with the purpose of confirming their 1 C. Brandi, Teoria…, p. 123. 2 Ibidem. 3 Ibidem.

The project here presented is the result of the collaboration
established between the Laboratory DAda Lab (Drawing and Architecture DocumentActionLaboratory) of the University of Pavia and the Laboratory SMlab (Survey and Modeling Lab of Architectural Heritage) of the University of Granada, together with the invaluable support received from the Board of the Alhambra and Generalife. Several professors and researchers have participated in this multidisciplinary project that, using the Generalife as a test, proposed a theoretical and practical methodology about the digital architectural survey, which has allowed to compare the different three-dimensional data formats in terms of their capacity to be interpreted in the process of conservation and management of architectural heritage. The experiences obtained in the different survey processes were completed with a rigorous historical analysis of the formal and constructive evolution of the Generalife, from which it has been possible to carry out the subsequent critical assessment.

In this contribution, a multidisciplinary investigation regarding the Roman Amphitheatre in Lecce, southern Italy, is be proposed. In particular, GPR prospecting combined to passive seismic measurements and with a virtual reconstruction of the monument allows deducing some important features of the monument, unknown before. In particular, this is a monument only partially brought to light, and part of it lies under the current Saint Oronzo's Square. We have investigated about the part still undiscovered of the amphitheatre.

Este trabalho consiste no desenvolvimento de um método para a usinagem a laser de modelos 3D em máquinas galvanométricas pós-objetivas, por meio da gravação de múltiplas camadas bidimensionais. Foi realizado um estudo para estabelecer os parâmetros de processo por meio de ensaios e ajustes no equipamento utilizado. Com o desenvolvimento de um dispositivo para controle do deslocamento vertical da mesa de trabalho, foi possível determinar com exatidão o ponto focal, bem como o passo da máquina (altura da camada). O substrato utilizado no estudo foi o PMMA Poli(metacrilato de metila) com um laser de CO2 de 43 W. Foram ensaiados os parâmetros de largura e profundidade dos rasgos formados pelo laser, bem como o ângulo de incidência. Foi possível determinar a profundidade da camada usinada em função dos parâmetros avaliados, bem como produzir modelos 3D com camadas de até 0,2 mm (com velocidade de 100 m/min e espaçamento entre linhas de 0,04 mm). Análises dimensionais foram realizadas por digitalização tridimensional, as quais mostraram erros médios na ordem de 0,1 mm nas peças produzidas. O resultado evidencia o potencial desta pesquisa ao propiciar a criação de uma nova funcionalidade para máquinas de gravação a laser, por exemplo, para fab labs e laboratórios de criação e design, para confecção de pequenos protótipos.

Il seminario internazionale “Lettura e progetto del castello di Kyrenia” è uno dei risultati della collaborazione scientifica in corso tra la Girne American University (Dipartimento di Architettura degli Interni) con il Dipartimento di Architettura dell’Università di Firenze e il Dipartimento di Architettura degli İnterni della Özyeğin University. Il seminario si è svolto tra il 6 e il 13 maggio 2018, presso la Girne American University, a Cipro.

The workshop “Reading and Designing the Kyrenia Castle” is one the results of the ongoing scientific collaboration between Girne American University (Department of Interior Architecture), with the Department of Architecture of the University of Florence and the Department of Interior Architecture of Özyeğin University. The workshop took place between the 6th and the 13th of May 2018, at Girne American University, Cyprus.

The NOAA Navigation Response Teams (NRTs) perform hydrographic surveys to support nautical charting updates for 175 ports of the United States Marine Transportation System.
These include the identification of bathymetric and anthropogenic features that may pose a danger to navigation. In addition, NRTs respond to emergencies, speed the resumption of shipping after storm events, and protect life and property from underwater dangers. The spectrum of dangers occurs from natural features, such as rocks to anthropogenic objects such as piers.

Previous work conducted by the NOAA Office of Coast Survey have shown that survey-grade laser scanners can be used to remotely map features that are dangers-to-navigation. However, the justifications to purchase these systems are difficult since one system can be on the order of several hundred thousand dollars. An alternative solution is proposed through the use of economical industrial laser scanners. The capabilities of these systems can vary widely with range and angular resolution and require additional integration (e.g., translation into geographic space and timing considerations) into the network of sensors typical of vessels engaged in
hydrographic operations. This paper presents evaluation work to balance cost versus performance using an industrial laser scanner into a hydrographic system. The laser scanner was
evaluated in a laboratory setting at the Joint Hydrographic Center / Center for Coastal and Ocean Mapping (CCOM/JHC), University of New Hampshire (UNH) water tank facilities and aboard the R/V Coastal Surveyor (Portsmouth Harbor, NH). The results of the study include a first-order analysis of Velodyne’s VLP-32E system and its target detection performance on piers, piles, air gaps and overhanging cables.

Forecasting of the timing of slope failure has been widely modelled using strain-rate based approaches. Such techniques are reliant upon high-precision data on slope deformation, yet conventionally a trade-off between monitoring precision and spatial resolution has to be made in mine slope safety systems. Newly available full-waveform terrestrial laser scanners (FW-TLS) have been shown capable of capturing detailed additional metrics of rock-slope surfaces, which from sequential scans allow significantly reduced uncertainties in change detection. Innovatively, this approach obtains both geometric and radiometric target surface information which is suited to the measurement of very small-scale deformation, whilst retaining the spatially rich detail of TLS point-clouds.
We present data captured using this new technology integrated into the slope safety monitoring system ‘SiteMonitor’, to explore the opportunities offered by this new technology in characterising actively failing rock slopes in new ways. Results presented highlight the ability to resolve surface features at a scale appropriate to precursory mass wasting and creep in unstable rock-slopes. These findings open the possibility for a step-change in the integration of recent strain-rate based predictive models with the unprecedented level of combined precision and detail offered by newly available FW-TLS data.

The multidisciplinary activities of the research project, involving several case studies of Romanesque Churches built up during the Sardinia Age of the Giudici (ranging from the eleventh to the thirteenth centuries), consist of three main phases: – 1st phase: work activities in situ (mapping and sampling of stones and alteration forms, digital and photogrammetric survey, study of significant stylistic and architectural features of monuments); – 2nd phase: laboratory investigations on the compositional and intrinsic characteristics of geomaterials (chemical, mineralogical, petrographic and physical-mechanical analyses) and alteration processes on the materials, highlighting the chemical and physical features; - 3rd phase: to define the relationships between the architectural monument/built-up site, both in a historical and modern perspective, the factors influencing the choice in construction materials, as well as, a methodological protocol for restoration (and valorisation) of monuments.

The research activity aims to evaluate the Mobile Laser Scanner mapping system's effectiveness and critical issues based on simultaneous localization and mapping (SLAM) called KAARTA Stencil. The research introduces a reflection on a series of test datasets resulting from the mobile system's application in an urban context taken as a case study and aimed at the representation and 3D modeling of architectural complexes. In detail, the metric accuracy of the proposed method was evaluated through a comparative analysis of the point cloud data through the evaluation of the surface deviation of the 3D point clouds based on the SLAM system and the data of static measurement systems, more precise to evaluate the accuracy of the proposed acquisition system. For each data were specified the possibilities of representation, the type of representation scale, and the possible manipulations and extractions of 2D profiles to design and analyze architectural elements through mobile systems. The analysis involves a breakdown of the problem of representation, identifying protocols that can be applicable at different levels and scales of reading aimed at the representation and discretization of parts and elements linked together in a hierarchical or interconnected relationship, outlining their criticality and potential. 1.

Civil infrastructure systems is important in terms of both safety and serviceability. So, large structure have been monitored using surveying techniques, while fine-scale monitoring of structural components has been done with geotechnical instrumentation. The advantages and disadvantages of using remote sensing methods, such as terrestrial laser scanning and digital close range photogrammetry, for the purposes of precise 3D reconstruction and the estimation of deflections in structural elements. This paper investigate that terrestrial laser scanner can be used for the monitoring of concrete beams subjected to different loading conditions. The system used does not require any physical targets. The setup was tested, and the beam deflections resulted from the 3D model from terrestrial laser scanner system were compared to the ones from ANSYS program. The experiments proved that it was possible to detect sub-millimeter level deformations given the used equipment and the geometry of the setup. Calculations and analysis of results are presented.

Terrestrial laser scanner (TLS) is a new class of survey instruments to capture spatial data developed rapidly. A perfect facility in the oil industry does not exist. As facilities age, oil and gas companies often need to revamp their plants to make sure the facilities still meet their specifications. Due to the complexity of an oil plant site, there are difficulties in revamping, having all dimensions and geometric properties, getting through narrow spaces between pipes and having the description label of each object within a facility site. So it is needed to develop an accurate observations technique to overcome these difficulties. TLS could be an unconventional solution as it accurately measures the coordinates identifying the position of each object within the oil plant and provide highly detailed 3D models. This paper investigates creating 3D model for Ras Gharib oil plant in Egypt and determining the geometric properties of oil plant equipment (tank, vessels, pipes. .. etc.) using TLS observations and modeling by CADWORX program. The modeling involves an analysis of several scans of the oil plant. All the processes to convert the observed points cloud into a 3D model are described. The geometric properties for tanks, vessels and pipes (radius, center coordinates, height and consequently oil volume) are also calculated and presented. The results provide a significant improvement in observing and modeling of an oil plant and prove that the TLS is the most effective choice for generating a representative 3D model required for oil plant revamping.

The main objective of this paper is to establish a procedural method for measuring and cataloguing antlers through the use of laser scanner and of a 3D reconstruction of complex modeling. The deer's antlers have been used as a test and subjected to capture and measurement. For this purpose multiple data sources techniques have been studied and compared, (also considering low-cost sensors) estimating the accuracy and its errors in order to demonstrate the validity of the process. A further development is the comparison of results with applications of digital photogrammetry, considering also cloud computing software.

The study has began with an introduction to sensors, addressing the underlying characteristics of the technology available, the scope and the limits of these applications. We have focused particularly on the "structured light", as the acquisition will be completed through three-dimensional scanners: DAVID and the ARTEC MH.

The first is a low-cost sensor, a basic webcam and a linear laser pointer, red coloured, that leads to acquisition of three-dimensional strips. The other one is a hand scanner; even in this case we will explain how to represent a 3D model, with a pipeline that provides data export from the "proprietary" to a "reverse engineering" software. Typically, these are the common steps to the two approaches that have been performed in WRAP format: point sampling, manual and global registration, repair normals, surface editing and texture projection. In fact, after a first and common data processing was done with the use of a software supplied with the equipment, the proto-models thus obtained were treated in Geomagic Studio, which was also chosen to allow the homogenization and standardization of data in order to make a more objective comparison.

It is commonplace to observe that the editing of the digital mock-up obtained with the DAVID – which had not yet been upgraded to the 3.5 release at the time of this study - is substantially different. In the ARTEC digital mock-up for example, it shows the ability to select the individual frames, already polygonal and geo-referenced at the time of capture; however, it is not possible to make an automated texturization differently from the low-cost environment which allows to produce a good graphics’ definition. Once the final 3D models were obtained, we have proceeded to do a geometric and graphic comparison of the results. Therefore, in order to provide an accuracy requirement and an assessment for the 3D reconstruction we have taken into account the following benchmarks: cost, captured points, noise (local and global), shadows and holes, operability, degree of definition, quality and accuracy.

Subsequently, these studies carried out in an empirical way on the virtual reconstructions, a 3D documentation was codified with a procedural method endorsing the use of terrestrial sensors for the documentation of antlers. The results thus pursued were compared with the standards set by the current provisions (see "Manual de medición" of Government of Andalusia-Spain); to date, in fact, the identification is based on data such as length, volume, colour, texture, openness, tips, structure, etc. Data, which is currently only appreciated with traditional instruments, such as tape measure, would be well represented by a process of virtual reconstruction and cataloguing.

IT - Uno dei principali effetti indotti dai cambiamenti climatici osservabili nel territorio nazionale è la localizzazione di fenomeni meteorologici di eccezionale intensità in aree ristrette. Accade che disastri naturali (quali alluvioni e inondazioni) stiano assumendo in molte zone d’Italia – ma non solo – una periodicità assai più elevata rispetto al passato. Il contributo descrive una prima applicazione di condivisione in rete di dataset ad alta risoluzione (derivati da dati LiDAR) impiegata in aree
di studio della Regione Veneto caratterizzate da un significativo rischio idrogeologico, nonché dai conseguenti dissesti territoriali. Nello specifico la ricerca propone una nuova modalità di gestione di dati 3D (nuvole di punti, mesh …), di trasmissione e di visualizzazione degli stessi via internet. Si ritiene che tale tecnologia possa essere considerata uno strumento di rapido supporto alle decisioni e al tempo stesso di archiviazione e consultazione ex post dei dati raccolti in fase critica. Il valore aggiunto desumibile dal primo caso test delle provincie di Verona e Vicenza (cfr. esondazioni dei Torrenti Tramigna, Alpone, Aldegà e Chiampo del 2010) risiede nella rapidità di integrazione tra il rilievo 3D dell’area oggetto dell’evento calamitoso e i diversi livelli informativi disponibili

EN - One of the main consequences of climate changes in Italy is the occurrence of meteorological phenomena of outstanding intensity in small areas. In many of them natural disasters (floods and flafloods, for instance) are becoming more frequent. The paper aims at describing a first attempt to apply a high resolution dataset web sharing tool (using LiDAR data) to case study areas located in the Veneto region. Such areas are characterized by a high hydrogeological risk and by territorial
instability. Our research suggests a new way of managing 3D data (point clouds, mesh..) as well as of transmitting and visualizing them via internet. Such a technology represents a flexible tool allowing to rapidly support decisions and store/consult ex-post data obtained in crucial phases of the phenomena studied.
Our research provides a general and enabling methodology for a rapid integration of 3D surveys of areas involved in disasters (in our case the one hit by the autumn 2010 floods caused by the Torrenti Tramigna, Alpone, Aldegà and Chiampo) and different available layers. The added value of our proposal, gathered from the first tests carried out on the Provinces of Verona and Vicenza, lies in this and in the quick interrogation of data and interactions

Documenting large architectures with an accurate survey has recently become possible even with a limited budget. Digital survey tools based on both active and passive solutions, offers today versatile opportunities for the architectural documentation, regardless of the building's dimension. This paper presents the poster, prepared for the CHNT conference, with an extract of Terrestrial and Aerial Photogrammetry and Terrestrial Lasergrammetry. This was used by academics in the context of the Kyrenia Castle in the Cyprus Island, a large medieval fortification organized in an almost square planimetry with a side of about 150 meters and walls height up to about 30 meters, gathering the occasion of a specific workshop (activated for one week in May 2018) and producing the first (partial) digital model of this large built heritage. Following the protocols and best practice in digital documentation of this kind of architectures-the coordinator group of the workshop in synergy with the management unit of the museum hosted in the castle-has brought on an articulated experience moving from the morphology of the castle, to its stratigraphy, to its exhibition aspects, to its restoration issues, to the production of multimedia contents for technical and/or general public access. In that poster it was presented the structure of the workshop, the structure of the survey, the interactions and integrations between different surveys, the system of tools, and the results coming out at first, from the on-field operations brought on by the students participating to the workshop and the following processing operated by technical expert operators; going on to the development of common digital bases to evolve the way of approach to these monumental structures. To present the complete workflow with samples the poster was enriched with QR-Code links to online resources has been made to be a useful base for sharing and discussing the whole set of activities completed on this subject.

A Via Nova, ou Geira, como é localmente conhecida, apresenta, no conjunto do seu traçado entre Bracara Augusta e Asturica Augusta, uma das maiores coleções de epigrafia viária atualmente reconhecidas na Península Ibérica. Classificada como Monumento Nacional entre as milhas XIV e XXXIV, encontram-se ainda nesta parte do traçado cerca de 114 dos 140 miliários referenciados, a maioria dos quais presente no local da respetiva milha que assinala.
A Unidade de Arqueologia da Universidade do Minho e o Município de Terras de Bouro retomaram a investigação do traçado classificado, com vista ao desenvolvimento de um plano de valorização e gestão integrada deste bem patrimonial. No âmbito deste projeto, foi avaliada uma metodologia de recuperação volumétrica dos miliários depositados no Museu da Geira e na Galeria do Miliários, através de um scanner de mão 3D utilizado em ambiente controlado, no caso o Sense®, da 3D Systems. Com vista à evidenciação dos campos epigráficos, altamente erosionados, a malha volumétrica gerada pelo scanner foi pós-processada em ambiente VTK e MeshLab. Os filtros aplicados à superfície da malha permitiram realçar sobremaneira campos epigráficos que, a olho nu, se afiguram ilegíveis.
Consideramos que a rapidez de levantamento e a qualidade dos modelos obtidos tornam o Sense® numa ferramenta que, tendo um baixo custo de aquisição, devolve resultados bastante satisfatórios face à escala do pretendido e às especificidades do levantamento.

Livorno, in Tuscany represent the main harbor in this part of the Mediterranean coast. With the establishment of the Free Port, in 1676, the arrival of merchants was favored and the demand for warehouses, capable of accumulating goods in the port of transit, increased considerably. For this reason, the system of fortifications was strengthened towards the sea and modernized by Cosimo III. Along with the modifications of the fortifications of the city, the project of a fort at the extremity of the “Molo di Cosimo” was also entrusted to the Grand-Ducal Architect Pier Maria Baldi in 1684. General Alessandro Dal Borro chose the design model and supervised the construction of the fort, which began in 1688 at the tip of the “Molo Cosimo”. The complex could control both the interior of the port and the open sea. The main function assigned by the authorities to this fortress was to bomb ships that intended to violate the neutrality declared in 1646, becoming, in fact, a peaceful observatory that, even in moments of tension, did not fire a shot to attack. Thus, it was equipped with an extended system of tunnels to allow the safe movement of people, ammunitions and cannons in case of a battle. This war machine is now in a quite complex state of abandon with a serious loss of architectural identity, mined by fragmented architectures growth all around the fortifications and with the galleries filled with the ruins remained around after the World War II bombings. In 2017-2018 for the first time after 70 years, the Port Authority of Livorno, operated the full removal of the ruins fitted in the galleries, allowing a complete digital survey of an architecture finally brought back to have a chance or revitalization. In this paper it will be presented the products of this research, showing the accurate and unedited representation of this long-lost fortress.

The Opera Punta Rossa fortification was built at the end of XIX century (1887) on the South of Caprera island (North Sardinia), when returned to thinking of La Maddalena archipelago as a strategic military centre, no longer determining in relation to the only French border, but to the much larger chessboard of the Western Mediterranean. It is of singular interest not only for the functional parameters but, above all, for its imposing appearance with wide dimensions, and other many interesting technical-architectural aspects: laying modes of wall structural elements (i.e., for access portals, intrados of vaults, moldings, architraves, jambs, thresholds, cantons), use and working technics of the granite stone expertly molded for the thick masonry, characterized by the presence of loopholes and continuous modulation of materials with moldings and worked stone ashlars to highlight the wall surface. The geomaterials used are local rocks outcropping in the area of Opera Punta Rossa, belonging to the Paleozoic granitic pluton of Gallura and to the associated filonean bodies (Upper Permian - Carboniferous, between about 320 and 270 million years ago). In the fortification have been mainly used the "granite" rocks (substantially biotitic granites and granodiorites) and subordinately also the filonean rocks (especially for irregular ashlars) with variable colours and dacitic-rhyodacitic composition. Generally, the cornices and the openings were made with the lighter greyish granite facies. The stone elements were laid in place using lime or hydraulic / pozzolanic based mortars. Conglomerates and cement-based concretes were used for throwing pitches in even thicker castings. In some subsequent renovations, bricks were also used. The photographic and digital relief was carried out using laser scanner methodologies, which has allowed to define the conservation status of the Opera Punta Rossa complex, producing a 3D model of the current state of building.

Se presenta un estudio sobre la iglesia de San Felix en Torralba de Ribota, Aragón (España), un edificio gótico-mudéjar ejemplo de la tipología de iglesias fortaleza. El trabajo incluye un estudio histórico de su construcción y sus posteriores restauraciones, la recolección de los levantamientos gráficos realizados en el siglo XX y un levantamiento actualizado del interior y el exterior del edificio por medio de técnicas digitales (fotogrametría aérea y escaneado láser). Este ha permitido el análisis geométrico completo de las dimensiones y proporciones del edificio, especialmente los arcos y bóvedas. La comparación con la documentación gráfica antigua ha revelado inexactitudes en esta, por lo que este trabajo aporta nueva información de interés.