Integration Of Laser Scanning Research Articles

SURVEY METHODOLOGIES AND 3D MODELLING FOR CONSERVATION OF HISTORICAL MASONRY BRIDGES

Abstract. The safeguarding and conservation of built heritage and historical infrastructures represent complex tasks, especially for administrations and stakeholders operating on peculiar and unique territories with specific cultural, social, and economic problems, such as the historical centres of Inner Areas. However, heritage conservation and management processes can be facilitated by multidisciplinary knowledge methodologies based on solutions offered by digital technologies in the field of documentation. This paper aims at defining novel procedures able to enhance available tools towards a real heritage e-government and e-conservation. The integration of laser scanning and photogrammetric survey-based techniques, as well as on the data of the multidisciplinary analysis available in a virtual environment, the implementation of the parametric model of a historical infrastructure has been investigated for assessing the issues related to the preservation and maintenance of these infrastructures, also in relation to their safety and enhancement. The application to a real case study pointed out the opportunities offered by new technologies in the integration of data coming from different research fields, and the reliability of parametric models in visual inspections and, as a consequence, in the planning of interventions of safeguard and conservation as well as those of valorisation of the historical heritage.

HBIM, 3D drawing and virtual reality for archaeological sites and ancient ruins

<p class="VARAbstract">Data collection, documentation and analysis of the traces of ancient ruins and archaeological sites represent an inestimable value to be handed down to future generations. Thanks to the development of new technologies in the field of computer graphics, Building Information Modelling (BIM), Virtual Reality (VR) and three-dimensional (3D) digital survey, this research proposes new levels of interactivity between users and virtual environments capable of communicating the tangible and intangible values of remains of ancient ruins. In this particular field of development, 3D drawing and digital modelling are based on the application of new Scan-to-HBIM-to-VR specifications capable of transforming simple points (point clouds) into mathematical models and digital information. Thanks to the direct application of novel grades of generation (GOG) and accuracy (GOA) it has been possible to go beyond the creation of complex models for heritage BIM (HBIM) and explore the creation of informative 3D representation composed by sub-elements (granular HBIM objects) characterized by a further level of knowledge. The value of measurement, 3D drawing and digital modelling have been investigated from the scientific point of view and oriented to the generation of a holistic model able to relate both with architects, engineers, and surveyors but also with archaeologists, restorers and virtual tourists.</p><p>Highlights:</p><ul><li><p>The concept of ‘granular HBIM objects’ is introduced to show the unexpressed potential of the scan-to-BIM process for different types of data analyses and uses.</p></li><li><p>Sustainable development of VR projects for archaeological sites is proposed, allowing users to discover the hidden historical values with new levels of interactivity and information.</p></li><li><p>HBIM and VR projects have been improved through the integration of laser scanning, digital photogrammetry (terrestrial and UAV) and advanced modelling techniques.</p></li></ul>

Integration of Laser Scanning and Three-dimensional Models in the Legal Process Following an Industrial Accident.

BackgroundIn order to obtain a deeper understanding of an incident, it needs to be investigated to “peel back the layers” and examine both immediate and underlying failures that contributed to the event itself. One of the key elements of an effective accident investigation is recording the scene for future reference. In recent years, however, there have been major advances in survey technology, which have provided the ability to capture scenes in three dimension to an unprecedented level of detail, using laser scanners.MethodsA case study involving a fatal incident was surveyed using three-dimensional laser scanning, and subsequently recreated through virtual and physical models. The created models were then utilized in both accident investigation and legal process, to explore the technologies used in this setting.ResultsBenefits include explanation of the event and environment, incident reconstruction, preservation of evidence, reducing the need for site visits, and testing of theories. Drawbacks include limited technology within courtrooms, confusion caused by models, cost, and personal interpretation and acceptance in the data.ConclusionLaser scanning surveys can be of considerable use in jury trials, for example, in case the location supports the use of a high-definition survey, or an object has to be altered after the accident and it has a specific influence on the case and needs to be recorded. However, consideration has to be made in its application and to ensure a fair trial, with emphasis being placed on the facts of the case and personal interpretation controlled.

ACCURACY ASSESSMENT IN STRUCTURE FROM MOTION 3D RECONSTRUCTION FROM UAV-BORN IMAGES: THE INFLUENCE OF THE DATA PROCESSING METHODS

Abstract. The evolution of Structure from Motion (SfM) techniques and their integration with the established procedures of classic stereoscopic photogrammetric survey have provided a very effective tool for the production of three-dimensional textured models. Such models are not only aesthetically pleasing but can also contain metric information, the quality of which depends on both survey type and applied processing methodologies. An open research topic in this area refers to checking attainable accuracy levels. The knowledge of such accuracy is essential, especially in the integration of models obtained through SfM with other models derived from different sensors or methods (laser scanning, classic photogrammetry ...). Accuracy checks may be conducted by either comparing SfM models against a reference one or measuring the deviation of control points identified on models and measured with classic topographic instrumentation and methodologies. This paper presents an analysis of attainable accuracy levels, according to different approaches of survey and data processing. For this purpose, a survey of the Church of San Miniato in Marcianella (Pisa, Italy), has been used. The dataset is an integration of laser scanning with terrestrial and UAV-borne photogrammetric surveys; in addition, a high precision topographic network was established for the specific purpose. In particular, laser scanning has been used for the interior and the exterior of the church, with the exclusion of the roof, while UAVs have been used for the photogrammetric survey of both roof, with horizontal strips, and façade, with vertical strips.

Integration of laser scanning and thermal imaging in monitoring optimization and assessment of rockfall hazard: a case history in the Carnic Alps (Northeastern Italy)

Rock cliff monitoring to evaluate related rockfall hazard requires a deep knowledge of the geometry and kinematics of the rock mass and a real-time survey of some key features. If a sedimentary rock system has sloping discontinuity planes, an open joint could become a potential sliding surface and its conditions must be monitored. It is the case of the Passo della Morte landslide (Carnic Alps, Northeastern Italy), where sub-vertical joints exist. Remote sensing techniques such as terrestrial laser scanning (TLS) and infrared thermography (IRT) allow a fast and efficient contactless geometrical and geomechanical examination of a rock mass. Therefore, they can be used to recognize those joints that require monitoring with on-site instrumentation such as extensometers and/or inclinometers, or also acoustic emission sensors, aiding the arrangement of monitoring systems which are generally quite expensive to install. Repeated IRT surveys would provide useful information about the evolution of unstable slopes, thus suggesting how the on-site monitoring system could be improved. Moreover, data gathered by TLS and IRT can be directly used in landslide hazard assessment. In the test site, an open joint was recognized together with a fair joint that could change in the next future. The results were validated by means of extensometer data.

Integration Of Three Dimensional Data From Unkown Origin On the Example Of A Traditional Residential Building In Al-Balad, Jeddah, Saudi Arabia

Abstract. 3D Laser scanning technology gained more and more importance for the recording and documentation of architectural heritage. Especially for the survey of heterogeneous surfaces and complex structures it is a fast and reliable option for survey and so appreciated sources for research in architecture. Therefore the integration of laser scanning as a part of the building survey became a kind of standard procedure for objects of different scale, shape, age and origin. In some cases more than one team records an object with different devices using altering approaches. For example a client provides existing data from a part of the object that can't be accessed anymore, but is important to be integrated into the overall survey. The merging of the datasets may become challenging, especially if one survey is not documented in detail, in particular when it comes to the quality of the result. For a research about the traditional architecture of Saudi Arabia a building in the historic part of Jeddah has been surveyed in detail by a team of researchers of the Vienna University of Technology. Within this frame a workshop for students of the King Abdul Aziz about building archaeological research has been conducted. As part of the results consists of two sets of laserscan data, recorded with different laser scanners. Using these data a possible approach for the registration of scan data from different and/or unknown provenance has been developed which will be outlined in this paper.