The progressive awareness of public administrations and society towards the necessity of preservi... more The progressive awareness of public administrations and society towards the necessity of preserving the cultural heritage, particularly rock art, has become more and more important in developed countries. In Galicia (northwest of Spain), there are many petroglyph remains that are seriously affected by a severe acceleration in degradation due to urban expansion. In this situation, actions focused on the preservation of these patrimonial elements have to be accomplished. These protection forms must be preceded by a previous step of exhaustive documentation of the prehistoric element, in order to register the conservation state of the element so that it can be contrasted with future observations or studies. The advances experimented by 3D digital techniques make possible to document rock art avoiding the inconveniences previously mentioned. The 3D digitalization of objects allows not only registering the metric and radiometric characteristics of objects, but also the diffusion and tran...
Universitario As Lagoas –Marcosende s/n 36200 Vigo Spain – (belenriveiro, parias, julia, firv, me... more Universitario As Lagoas –Marcosende s/n 36200 Vigo Spain – (belenriveiro, parias, julia, firv, merchisolla)@uvigo.es Commission V, WG V/2 ABSTRACT: This paper describes the project of the Close Range Photogrammetry and Remote Sensing Group, University of Vigo, Spain, involving historic arch bridges in Galicia, Spain. The first aim of this Project consists on building a database of the historic arch bridges in Galicia, documenting location, surroundings, geometry, singular characteristics, structural faults, building material and state of conservation. On the other side, a methodology is being designed to optimize measuring and analysing techniques: Close Range Photogrammetry and Laser Scanning as 3D modelling tools for geometry and cracks documentation (Arias et al, 2005), Ground Penetrating Radar for inner material characterization and zones description, and FEM as structural analysis tool to establish stress distribution compatible with the detected damages, allowing identifying i...
Proceedings of the 3rd International Workshop on Advanced Ground Penetrating Radar, 2005. IWAGPR 2005., 2005
A key factor for the accurate interpretation of surface-penetrating radar records is to know as m... more A key factor for the accurate interpretation of surface-penetrating radar records is to know as much as possible about the transmission features of our antennas. The characteristics of the detected reflections (trace time zero, duration and shape of the reflected pulse, minimum overlap distance between direct signal and first reflection, etc) depend on the issued signal properties. Since these characteristics can vary for the different GPR equipments available, in this paper we present the results of various experiments to analyze and calibrate 500, 800 and 1000 MHz shielded antennas Index Terms-Ground penetrating radar, spherical spread attenuation, stacking, time aliasing, time base drift, trace time zero.
The dimensions of façades and window openings in buildings are usually determined by direct measu... more The dimensions of façades and window openings in buildings are usually determined by direct measurements using tapes and plummets. In this paper, we present a semi-automated application that makes it possible to obtain building measurements by means of an indirect method based on close-range photogrammetry. This application is intended to be used with a single planar-surface measuring system that permits measurements to be made without contact with the building. This system combines the output from a digital off-the-shelf camera and a laser distance meter. These data are used within our application for image orientation and scaling. Next, the software permits calculation of the dimensions of elements on the planar façade and also provides an estimate for the precision of those dimensions. This indirect approach avoids time-consuming and risky procedures in building measurement and permits the user to take inventory of a building under construction.
Usually, determining the dimensions of flat surfaces in buildings under construction, such as win... more Usually, determining the dimensions of flat surfaces in buildings under construction, such as window cavities and façade coating materials, are done by direct measuring methods using tapes and plummets. Sometimes these methods suppose a slow and highly risky work for operators. This research proposes the substitution of these procedures by indirect methods based on close range photogrammetry and laser distance measurement. First, we show the design, construction and calibration of a system composed by a digital camera and a lasermeter mounted on a support with multiple turning positions. Next, two different façade element measuring methodologies are shown. The first method is based on taking a single photograph and measuring the distance to the object. The second one is based on taking three photographs and three distances measured at three different calibrated positions. Finally the accuracy of each methodology is analyzed and the pros and cons of each one are shown.
Computer-Aided Civil and Infrastructure Engineering, 2014
ABSTRACT This article proposes a method to semiautomatically extract the road axis through a mobi... more ABSTRACT This article proposes a method to semiautomatically extract the road axis through a mobile LiDAR system, a recent popular technology for transportation-related applications, road estimation and even to enhance driver safety. In particular, the approach developed has two components: (1) the feature extraction from LiDAR data to model the road axis, and (2) the estimation of the horizontal alignment that meets the requirements and practice for a transportation authority. Given the massive and complex character of the data captured by the system, a hierarchical (coarse-to-fine) and robust strategy based on segmentation, parameterization and filtering, which determine the road centerline together with the geometric elements that compose its horizontal alignment, such as straight lines, circular arcs, and clothoids, has been developed and implemented. Test results using a simulated and a real data are discussed and validated. The experimental results obtained with real cases guarantying relative accuracies under 2%, being a useful approach to produce accurate estimations of the horizontal geometric features of the road alignment.
Proceedings of the 2012 18th International Conference on Virtual Systems and Multimedia, VSMM 2012: Virtual Systems in the Information Society, 2012
ABSTRACT The use of Building Information Models (BIM) for energy analysis is becoming a common ap... more ABSTRACT The use of Building Information Models (BIM) for energy analysis is becoming a common application, supported by the appearance of standards and regulations restricting energy consumption and energy efficiency in the building sector. BIMs from already built buildings are being generated with the help of high-technology devices such as laser scanners, which acquire the physical reality of a scene with high accuracy in a short time. However, the environment of the building, and especially surfaces producing shades, which are essential for the performance of meaningful energy studies, is usually forgotten as the focus is set on the representation of complex geometries. With the aim of generating a BIM able to be subjected to energy analysis, this paper presents a working methodology including data acquisition with a laser scanner, shape extraction of the building itself and its surroundings, and conversion of extracted elements, including shade surfaces, to BIM components.
ABSTRACT This paper presents a working methodology for the automatic generation of as-built Build... more ABSTRACT This paper presents a working methodology for the automatic generation of as-built Building Information Models (BIMs) including shade surfaces able to be subjected to solar analysis, given the great effect that shading has in the energy consumption of the building. This methodology goes from data acquisition with a laser scanner, to the shape extraction of the building and its surroundings from the acquired data through curvature analysis and Region Growing algorithms, to end with the conversion of the extracted elements, which define both the building and the shading elements, to BIM components. BIM is defined in gbXML language, which was especially designed to be used in energy software, so that the generated BIM with shades can be directly introduced in energy analysis software.
Journal of Performance of Constructed Facilities, 2014
ABSTRACT Monitoring of breakwaters is a key aspect to prevent failures that affect the safety and... more ABSTRACT Monitoring of breakwaters is a key aspect to prevent failures that affect the safety and quality of service. Unmanned aerial vehicle (UAV) photogrammetry gives low-cost and accurate geometric data, flexibility, and productivity to perform aerial surveys, although the weather conditions restrict flights for wind speeds above 50 km/h (the Mikrokopter system). Despite the promising potential of these systems, its ability to monitor movement of cubes in breakwaters has not yet proven. The UAV photogrammetry is tested for the research reported in this paper in the Baiona breakwaters (northwestern Spain). A SD of 0.026 m is obtained from the point cloud. The detection limit of the system is evaluated and rotations lower than 1° could be detected. This value is calculated from the measurable differences in height values after the virtual rotation of a single cube. The system provides the exact position where the movement of the cube is produced and can be easily integrated with geographic information system–based management systems.
ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Inf. Sciences, 2014
Rubble mound breakwaters are coastal defense structures that protect harbors and beaches from the... more Rubble mound breakwaters are coastal defense structures that protect harbors and beaches from the impacts of both littoral drift and storm waves. They occasionally break, leading to catastrophic damage to surrounding human populations and resulting in huge economic and environmental losses. Ensuring their stability is considered to be of vital importance and the major reason for setting up breakwater monitoring systems. Terrestrial laser scanning has been recognized as a monitoring technique of existing infrastructures. Its capability for measuring large amounts of accurate points in a short period of time is also well proven. In this paper we first introduce a method for the automatic extraction of face geometry of concrete cubic blocks, as typically used in breakwaters. Point clouds are segmented based on their orientation and location. Then we compare corresponding cuboids of three co-registered point clouds to estimate their transformation parameters over time. The first method is demonstrated on scan data from the Baiona breakwater (Spain) while the change detection is demonstrated on repeated scan data of concrete bricks, where the changing scenario was simulated. The application of the presented methodology has verified its effectiveness for outlining the 3D breakwater units and analyzing their changes at the millimeter level. Breakwater management activities could benefit from this initial version of the method in order to improve their productivity.
ABSTRACT Ground-penetrating radar (GPR) is a recommendable and cost-effective non-destructive tec... more ABSTRACT Ground-penetrating radar (GPR) is a recommendable and cost-effective non-destructive technique for measuring the thickness of pavement layers because data acquisition can take place at normal traffic speeds. On the other hand, the large amount of data collected is difficult to process. Given that processing is conducted by qualified practitioners, it is a key to obtain software tools that allow for accurate thickness measurements and fast processing times. This paper presents a new semi-automatic program for the processing and visualisation of GPR data to measure pavement thicknesses. The results showed that an optimisation in the execution time allowed for a near-immediate response in data processing even when dealing with large data sets. Different data set lengths, ranging from 100 m to 20 km, were analysed, and the processing times required to complete the entire process were examined taking into account three different hardware configurations (i3, i5 and i7 processors). In all cases, the processing times did not exceed 30 s. An additional test was performed to evaluate the reproducibility of the algorithm on a well-defined and preconditioned concrete asphalt course. Furthermore, the visualisation application allows for the georeferencing of the field GPR data by using additional GPS data.
Damage produced in the main armour of rubble mound breakwaters due to wave action is progressive ... more Damage produced in the main armour of rubble mound breakwaters due to wave action is progressive and different steps can be defined the wave action is beginning, while the breakwaters is falling. It is necessary to know the damage evolution during the service life of the structure in order to evaluate maintenance activities and adequately manage the breakwater. New possibilities exist now with terrestrial LiDAR systems, which can quickly scan huge data sets with increased levels of spatial detail and resolution in a very efficient manner.
The measurement and monitoring of structural damages in masonry monuments is an important task in... more The measurement and monitoring of structural damages in masonry monuments is an important task in the field of conservation and restoration of architectonic heritage. Traditional surveying devices provide punctual measurements of the damage size and usually are contactdemanding, being an important limitation since risky systems are needed when structural problems appear in no accessible locations. In this field close-range Photogrammetry depict a valuable option. In this paper the dimensional analysis and temporal monitoring of crack is accomplished. Accurate 3D clouds of points defining the crack boundary are obtained in different dates. A quantification of the crack size in each date is obtained by shape parameters. This procedure allows detecting any displacement in ashlars and obtaining a feasible knowledge of the crack growth even when no fixed references are available to align 3D models obtained in different times.
In this article, we present results that demonstrate the utility of close range photogrammetry in... more In this article, we present results that demonstrate the utility of close range photogrammetry in the measurement of decks in recreational craft as an alternate measurement system to the one based on direct acquisition of coordinates. The areas of deck covered with teakwood for aesthetic or security reasons were measured. Both methods were compared in terms of precision of measurements, time consumption, equipment cost, and ease of manipulation and equipment transportation. Based on the results, we conclude that photogrammetry has advantages in almost every aspect with respect to the direct method. Consequently, photogrammetry is suggested as a suitable method for coordinate measurement of decks in recreational ships. However, in some special circumstances, where ships have wide corridors with few obstacles the direct method can be more appropriate than the photogrammetric method.
In the cultural heritage field, the monitoring of the integrity of structures can greatly benefit... more In the cultural heritage field, the monitoring of the integrity of structures can greatly benefit from 3D digitising techniques. The aim of deformation analysis and structural surveillance is the early detection of damage in order to be able to react appropriately and in good time. The devices that have been traditionally used in the measurement of fissures, cracks and fractures are contact tools whose application depends on accessibility; moreover, they only provide discrete point measurements rather than giving a continuous record of the damage dimension in the whole affected area, as modern 3D modelling techniques can do. Among these techniques, close range photogrammetry is still the most complete, economical, portable, flexible and widely used approach in architectural applications. This paper is focused on the application of close range photogrammetry in the detection and monitoring of structural damage. The following procedure is proposed: the gathering at different epochs of 3D point clouds in the neighbourhood of cracks; the comparison among the successive point clouds by means of shape parameters; and the application of a bootstrap test for the detection of the significant statistical results. This procedure is applied to the analysis of structural damage detected in a masonry structure of cultural heritage interest: Basílica da Ascensión, located in the north-west of Spain.
The progressive awareness of public administrations and society towards the necessity of preservi... more The progressive awareness of public administrations and society towards the necessity of preserving the cultural heritage, particularly rock art, has become more and more important in developed countries. In Galicia (northwest of Spain), there are many petroglyph remains that are seriously affected by a severe acceleration in degradation due to urban expansion. In this situation, actions focused on the preservation of these patrimonial elements have to be accomplished. These protection forms must be preceded by a previous step of exhaustive documentation of the prehistoric element, in order to register the conservation state of the element so that it can be contrasted with future observations or studies. The advances experimented by 3D digital techniques make possible to document rock art avoiding the inconveniences previously mentioned. The 3D digitalization of objects allows not only registering the metric and radiometric characteristics of objects, but also the diffusion and tran...
Universitario As Lagoas –Marcosende s/n 36200 Vigo Spain – (belenriveiro, parias, julia, firv, me... more Universitario As Lagoas –Marcosende s/n 36200 Vigo Spain – (belenriveiro, parias, julia, firv, merchisolla)@uvigo.es Commission V, WG V/2 ABSTRACT: This paper describes the project of the Close Range Photogrammetry and Remote Sensing Group, University of Vigo, Spain, involving historic arch bridges in Galicia, Spain. The first aim of this Project consists on building a database of the historic arch bridges in Galicia, documenting location, surroundings, geometry, singular characteristics, structural faults, building material and state of conservation. On the other side, a methodology is being designed to optimize measuring and analysing techniques: Close Range Photogrammetry and Laser Scanning as 3D modelling tools for geometry and cracks documentation (Arias et al, 2005), Ground Penetrating Radar for inner material characterization and zones description, and FEM as structural analysis tool to establish stress distribution compatible with the detected damages, allowing identifying i...
Proceedings of the 3rd International Workshop on Advanced Ground Penetrating Radar, 2005. IWAGPR 2005., 2005
A key factor for the accurate interpretation of surface-penetrating radar records is to know as m... more A key factor for the accurate interpretation of surface-penetrating radar records is to know as much as possible about the transmission features of our antennas. The characteristics of the detected reflections (trace time zero, duration and shape of the reflected pulse, minimum overlap distance between direct signal and first reflection, etc) depend on the issued signal properties. Since these characteristics can vary for the different GPR equipments available, in this paper we present the results of various experiments to analyze and calibrate 500, 800 and 1000 MHz shielded antennas Index Terms-Ground penetrating radar, spherical spread attenuation, stacking, time aliasing, time base drift, trace time zero.
The dimensions of façades and window openings in buildings are usually determined by direct measu... more The dimensions of façades and window openings in buildings are usually determined by direct measurements using tapes and plummets. In this paper, we present a semi-automated application that makes it possible to obtain building measurements by means of an indirect method based on close-range photogrammetry. This application is intended to be used with a single planar-surface measuring system that permits measurements to be made without contact with the building. This system combines the output from a digital off-the-shelf camera and a laser distance meter. These data are used within our application for image orientation and scaling. Next, the software permits calculation of the dimensions of elements on the planar façade and also provides an estimate for the precision of those dimensions. This indirect approach avoids time-consuming and risky procedures in building measurement and permits the user to take inventory of a building under construction.
Usually, determining the dimensions of flat surfaces in buildings under construction, such as win... more Usually, determining the dimensions of flat surfaces in buildings under construction, such as window cavities and façade coating materials, are done by direct measuring methods using tapes and plummets. Sometimes these methods suppose a slow and highly risky work for operators. This research proposes the substitution of these procedures by indirect methods based on close range photogrammetry and laser distance measurement. First, we show the design, construction and calibration of a system composed by a digital camera and a lasermeter mounted on a support with multiple turning positions. Next, two different façade element measuring methodologies are shown. The first method is based on taking a single photograph and measuring the distance to the object. The second one is based on taking three photographs and three distances measured at three different calibrated positions. Finally the accuracy of each methodology is analyzed and the pros and cons of each one are shown.
Computer-Aided Civil and Infrastructure Engineering, 2014
ABSTRACT This article proposes a method to semiautomatically extract the road axis through a mobi... more ABSTRACT This article proposes a method to semiautomatically extract the road axis through a mobile LiDAR system, a recent popular technology for transportation-related applications, road estimation and even to enhance driver safety. In particular, the approach developed has two components: (1) the feature extraction from LiDAR data to model the road axis, and (2) the estimation of the horizontal alignment that meets the requirements and practice for a transportation authority. Given the massive and complex character of the data captured by the system, a hierarchical (coarse-to-fine) and robust strategy based on segmentation, parameterization and filtering, which determine the road centerline together with the geometric elements that compose its horizontal alignment, such as straight lines, circular arcs, and clothoids, has been developed and implemented. Test results using a simulated and a real data are discussed and validated. The experimental results obtained with real cases guarantying relative accuracies under 2%, being a useful approach to produce accurate estimations of the horizontal geometric features of the road alignment.
Proceedings of the 2012 18th International Conference on Virtual Systems and Multimedia, VSMM 2012: Virtual Systems in the Information Society, 2012
ABSTRACT The use of Building Information Models (BIM) for energy analysis is becoming a common ap... more ABSTRACT The use of Building Information Models (BIM) for energy analysis is becoming a common application, supported by the appearance of standards and regulations restricting energy consumption and energy efficiency in the building sector. BIMs from already built buildings are being generated with the help of high-technology devices such as laser scanners, which acquire the physical reality of a scene with high accuracy in a short time. However, the environment of the building, and especially surfaces producing shades, which are essential for the performance of meaningful energy studies, is usually forgotten as the focus is set on the representation of complex geometries. With the aim of generating a BIM able to be subjected to energy analysis, this paper presents a working methodology including data acquisition with a laser scanner, shape extraction of the building itself and its surroundings, and conversion of extracted elements, including shade surfaces, to BIM components.
ABSTRACT This paper presents a working methodology for the automatic generation of as-built Build... more ABSTRACT This paper presents a working methodology for the automatic generation of as-built Building Information Models (BIMs) including shade surfaces able to be subjected to solar analysis, given the great effect that shading has in the energy consumption of the building. This methodology goes from data acquisition with a laser scanner, to the shape extraction of the building and its surroundings from the acquired data through curvature analysis and Region Growing algorithms, to end with the conversion of the extracted elements, which define both the building and the shading elements, to BIM components. BIM is defined in gbXML language, which was especially designed to be used in energy software, so that the generated BIM with shades can be directly introduced in energy analysis software.
Journal of Performance of Constructed Facilities, 2014
ABSTRACT Monitoring of breakwaters is a key aspect to prevent failures that affect the safety and... more ABSTRACT Monitoring of breakwaters is a key aspect to prevent failures that affect the safety and quality of service. Unmanned aerial vehicle (UAV) photogrammetry gives low-cost and accurate geometric data, flexibility, and productivity to perform aerial surveys, although the weather conditions restrict flights for wind speeds above 50 km/h (the Mikrokopter system). Despite the promising potential of these systems, its ability to monitor movement of cubes in breakwaters has not yet proven. The UAV photogrammetry is tested for the research reported in this paper in the Baiona breakwaters (northwestern Spain). A SD of 0.026 m is obtained from the point cloud. The detection limit of the system is evaluated and rotations lower than 1° could be detected. This value is calculated from the measurable differences in height values after the virtual rotation of a single cube. The system provides the exact position where the movement of the cube is produced and can be easily integrated with geographic information system–based management systems.
ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Inf. Sciences, 2014
Rubble mound breakwaters are coastal defense structures that protect harbors and beaches from the... more Rubble mound breakwaters are coastal defense structures that protect harbors and beaches from the impacts of both littoral drift and storm waves. They occasionally break, leading to catastrophic damage to surrounding human populations and resulting in huge economic and environmental losses. Ensuring their stability is considered to be of vital importance and the major reason for setting up breakwater monitoring systems. Terrestrial laser scanning has been recognized as a monitoring technique of existing infrastructures. Its capability for measuring large amounts of accurate points in a short period of time is also well proven. In this paper we first introduce a method for the automatic extraction of face geometry of concrete cubic blocks, as typically used in breakwaters. Point clouds are segmented based on their orientation and location. Then we compare corresponding cuboids of three co-registered point clouds to estimate their transformation parameters over time. The first method is demonstrated on scan data from the Baiona breakwater (Spain) while the change detection is demonstrated on repeated scan data of concrete bricks, where the changing scenario was simulated. The application of the presented methodology has verified its effectiveness for outlining the 3D breakwater units and analyzing their changes at the millimeter level. Breakwater management activities could benefit from this initial version of the method in order to improve their productivity.
ABSTRACT Ground-penetrating radar (GPR) is a recommendable and cost-effective non-destructive tec... more ABSTRACT Ground-penetrating radar (GPR) is a recommendable and cost-effective non-destructive technique for measuring the thickness of pavement layers because data acquisition can take place at normal traffic speeds. On the other hand, the large amount of data collected is difficult to process. Given that processing is conducted by qualified practitioners, it is a key to obtain software tools that allow for accurate thickness measurements and fast processing times. This paper presents a new semi-automatic program for the processing and visualisation of GPR data to measure pavement thicknesses. The results showed that an optimisation in the execution time allowed for a near-immediate response in data processing even when dealing with large data sets. Different data set lengths, ranging from 100 m to 20 km, were analysed, and the processing times required to complete the entire process were examined taking into account three different hardware configurations (i3, i5 and i7 processors). In all cases, the processing times did not exceed 30 s. An additional test was performed to evaluate the reproducibility of the algorithm on a well-defined and preconditioned concrete asphalt course. Furthermore, the visualisation application allows for the georeferencing of the field GPR data by using additional GPS data.
Damage produced in the main armour of rubble mound breakwaters due to wave action is progressive ... more Damage produced in the main armour of rubble mound breakwaters due to wave action is progressive and different steps can be defined the wave action is beginning, while the breakwaters is falling. It is necessary to know the damage evolution during the service life of the structure in order to evaluate maintenance activities and adequately manage the breakwater. New possibilities exist now with terrestrial LiDAR systems, which can quickly scan huge data sets with increased levels of spatial detail and resolution in a very efficient manner.
The measurement and monitoring of structural damages in masonry monuments is an important task in... more The measurement and monitoring of structural damages in masonry monuments is an important task in the field of conservation and restoration of architectonic heritage. Traditional surveying devices provide punctual measurements of the damage size and usually are contactdemanding, being an important limitation since risky systems are needed when structural problems appear in no accessible locations. In this field close-range Photogrammetry depict a valuable option. In this paper the dimensional analysis and temporal monitoring of crack is accomplished. Accurate 3D clouds of points defining the crack boundary are obtained in different dates. A quantification of the crack size in each date is obtained by shape parameters. This procedure allows detecting any displacement in ashlars and obtaining a feasible knowledge of the crack growth even when no fixed references are available to align 3D models obtained in different times.
In this article, we present results that demonstrate the utility of close range photogrammetry in... more In this article, we present results that demonstrate the utility of close range photogrammetry in the measurement of decks in recreational craft as an alternate measurement system to the one based on direct acquisition of coordinates. The areas of deck covered with teakwood for aesthetic or security reasons were measured. Both methods were compared in terms of precision of measurements, time consumption, equipment cost, and ease of manipulation and equipment transportation. Based on the results, we conclude that photogrammetry has advantages in almost every aspect with respect to the direct method. Consequently, photogrammetry is suggested as a suitable method for coordinate measurement of decks in recreational ships. However, in some special circumstances, where ships have wide corridors with few obstacles the direct method can be more appropriate than the photogrammetric method.
In the cultural heritage field, the monitoring of the integrity of structures can greatly benefit... more In the cultural heritage field, the monitoring of the integrity of structures can greatly benefit from 3D digitising techniques. The aim of deformation analysis and structural surveillance is the early detection of damage in order to be able to react appropriately and in good time. The devices that have been traditionally used in the measurement of fissures, cracks and fractures are contact tools whose application depends on accessibility; moreover, they only provide discrete point measurements rather than giving a continuous record of the damage dimension in the whole affected area, as modern 3D modelling techniques can do. Among these techniques, close range photogrammetry is still the most complete, economical, portable, flexible and widely used approach in architectural applications. This paper is focused on the application of close range photogrammetry in the detection and monitoring of structural damage. The following procedure is proposed: the gathering at different epochs of 3D point clouds in the neighbourhood of cracks; the comparison among the successive point clouds by means of shape parameters; and the application of a bootstrap test for the detection of the significant statistical results. This procedure is applied to the analysis of structural damage detected in a masonry structure of cultural heritage interest: Basílica da Ascensión, located in the north-west of Spain.
Uploads
Papers by Pedro Arias