Geomatics support to the metric documentation of the archaeological heritage. Tests and validations on the use of low-cost, rapid, image-based sensors and systems.

L'abstract è presente nell'allegato / the abstract is in the attachmen

An Efficient Point Cloud Processing Framework for Terrestrial and Mobile Lidar Data via Reconstructing the Scan Pattern Grid

Lidar (LIght Detection And Ranging) is a remote sensing technology using light in the form of a pulsed laser, which enables efficient, accurate, 3-D data acquisition of a scene. Depending on the mounting platform, lidar data acquisition can be categorized into Airborne Laser Scanning (ALS, or airborne lidar), Terrestrial Laser Scanning (TLS, or terrestrial lidar), and Mobile Laser Scanning (MLS, or mobile lidar). The lidar technique has been widely used for a plethora of applications including topographic mapping, bathymetric mapping, utility mapping, engineering surveying, agriculture, forestry, geology, architecture, industrial facilities, cultural heritage, asset management, construction, and so forth. However, efficiently processing the dense datasets produced by lidar still remains challenging given the large data volume. In addition, because of the scan pattern, range, view angle, and other factors, the point density for terrestrial and mobile lidar data can vary dramatically across the scene, which raises different challenges in developing robust processing methods compared with an ALS point cloud, which tends to be more evenly distributed. To overcome the challenges in processing TLS and MLS data, in this research, the point cloud is structured into a 2-D grid structure called the scan pattern grid, which represents the way that a scanner collects data. This dissertation, comprising four manuscripts, explores the possibilities and performance improvements of exploiting this scan pattern grid to process point cloud data. This first manuscript presents an efficient ground filtering method for TLS data via a Scanline Density Analysis. Ground filtering is a common procedure in lidar data processing, which separates the point cloud data into two classes: ground points and non-ground points. The proposed process first separates the ground candidates, density features, and unidentified points based on an analysis of point density within each scanline. Second, a region growth using the scan pattern clusters the ground candidates using the density features as boundaries and further refines the ground points. Both stages process and analyze the TLS data in each scan separately, exploiting the scan pattern grid for efficiency. The next two manuscripts develop a novel point cloud segmentation with an approach that links the scan pattern grids from multiple scans during the analysis. Point cloud segmentation groups points with similar attributes with respect to geometric, colormetric radiometric, and/or other information to help with object extraction and interpreting the point cloud. The proposed segmentation method only requires the basic geometric information and consists of two main steps. First, a novel feature extraction approach, NORmal VAriation ANAlysis (Norvana), eliminates some noise points and extracts edge points without requiring a general (and error prone) normal estimation at each point. Second, region growing groups the points on a smooth surface using the edge points as boundaries to obtain the segmentation result. Unlike TLS data that can be directly structured from a structured format (e.g., ASTM E57), Mobile lidar data is usually stored in an unorganized manner (e.g., ASPRS LAS). The final manuscript presents an efficient mobile lidar data processing framework including an approach to reconstruct the scanner trajectory such that an unorganized point cloud can be structured into the scan pattern grid based on the order of acquisition and revolutions of the scanner. Then the concept of Norvana for edge detection, normal estimation, feature extraction, and segmentation, is extended to be suitable for processing mobile lidar data and is named Mo norvana. Additionally, the proposed framework also introduces an efficient data visualization scheme exploiting the scan pattern grid. All of the proposed methods implement parallel processing to obtain a higher computational performance. The effectiveness, efficiency, robustness, and versatility are demonstrated both qualitatively and quantitatively by testing multiple terrestrial and mobile lidar datasets collected by different scanners with different spatial scales, resolutions, and scene types. The key contribution of this research is a generalized point cloud processing framework that can efficiently support a wide range of refinements, processes, and analysis for a variety of applications

Modeling and Simulation in Engineering

This book provides an open platform to establish and share knowledge developed by scholars, scientists, and engineers from all over the world, about various applications of the modeling and simulation in the design process of products, in various engineering fields. The book consists of 12 chapters arranged in two sections (3D Modeling and Virtual Prototyping), reflecting the multidimensionality of applications related to modeling and simulation. Some of the most recent modeling and simulation techniques, as well as some of the most accurate and sophisticated software in treating complex systems, are applied. All the original contributions in this book are jointed by the basic principle of a successful modeling and simulation process: as complex as necessary, and as simple as possible. The idea is to manipulate the simplifying assumptions in a way that reduces the complexity of the model (in order to make a real-time simulation), but without altering the precision of the results

3D Recording and Interpretation for Maritime Archaeology

This open access peer-reviewed volume was inspired by the UNESCO UNITWIN Network for Underwater Archaeology International Workshop held at Flinders University, Adelaide, Australia in November 2016. Content is based on, but not limited to, the work presented at the workshop which was dedicated to 3D recording and interpretation for maritime archaeology. The volume consists of contributions from leading international experts as well as up-and-coming early career researchers from around the globe. The content of the book includes recording and analysis of maritime archaeology through emerging technologies, including both practical and theoretical contributions. Topics include photogrammetric recording, laser scanning, marine geophysical 3D survey techniques, virtual reality, 3D modelling and reconstruction, data integration and Geographic Information Systems. The principal incentive for this publication is the ongoing rapid shift in the methodologies of maritime archaeology within recent years and a marked increase in the use of 3D and digital approaches. This convergence of digital technologies such as underwater photography and photogrammetry, 3D sonar, 3D virtual reality, and 3D printing has highlighted a pressing need for these new methodologies to be considered together, both in terms of defining the state-of-the-art and for consideration of future directions. As a scholarly publication, the audience for the book includes students and researchers, as well as professionals working in various aspects of archaeology, heritage management, education, museums, and public policy. It will be of special interest to those working in the field of coastal cultural resource management and underwater archaeology but will also be of broader interest to anyone interested in archaeology and to those in other disciplines who are now engaging with 3D recording and visualization

8th. International congress on archaeology computer graphica. Cultural heritage and innovation

El lema del Congreso es: 'Documentación 3D avanzada, modelado y reconstrucción de objetos patrimoniales, monumentos y sitios.Invitamos a investigadores, profesores, arqueólogos, arquitectos, ingenieros, historiadores de arte... que se ocupan del patrimonio cultural desde la arqueología, la informática gráfica y la geomática, a compartir conocimientos y experiencias en el campo de la Arqueología Virtual. La participación de investigadores y empresas de prestigio será muy apreciada. Se ha preparado un atractivo e interesante programa para participantes y visitantes.Lerma García, JL. (2016). 8th. International congress on archaeology computer graphica. Cultural heritage and innovation. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/73708EDITORIA

3D City Models and urban information: Current issues and perspectives

Considering sustainable development of cities implies investigating cities in a holistic way taking into account many interrelations between various urban or environmental issues. 3D city models are increasingly used in different cities and countries for an intended wide range of applications beyond mere visualization. Could these 3D City models be used to integrate urban and environmental knowledge? How could they be improved to fulfill such role? We believe that enriching the semantics of current 3D city models, would extend their functionality and usability; therefore, they could serve as integration platforms of the knowledge related to urban and environmental issues allowing a huge and significant improvement of city sustainable management and development. But which elements need to be added to 3D city models? What are the most efficient ways to realize such improvement / enrichment? How to evaluate the usability of these improved 3D city models? These were the questions tackled by the COST Action TU0801 “Semantic enrichment of 3D city models for sustainable urban development”. This book gathers various materials developed all along the four year of the Action and the significant breakthroughs