Image‐Based Modelling from Unmanned Aerial Vehicle (UAV) Photogrammetry: An Effective,Low‐Cost Tool for Archaeological Applications

The recording and 3D modelling of complex archaeological sites is usually associated with high capital and logistical costs, because the data acquisition must be performed by specialists using expensive surveying sensors (i.e., terrestrial laser scanners, robotic total stations and/or ground‐penetrating radar). This paper presents a novel, low‐cost, user‐friendly photogrammetric tool for generating high‐resolution and scaled 3D models of complex sites. The results obtained with unmanned aerial vehicle (UAV) photogrammetry of an archaeological site indicate that this approach is semi‐automatic, inexpensive and effective, and that it guarantees quality.     

Terrestrial laser scanning and close range photogrammetry for 3D archaeological documentation: the Upper Palaeolithic Cave of Parpalló as a case study

Graphic and metric archaeological documentation is an activity that requires the capture of information from different sources, accurate processing and comprehensive analysis. If monitoring of the state of conservation is required, this task has to be performed before intervention, during and after the completion of the works in a repetitive way.This paper presents the use of terrestrial laser scanning (TLS) in order to effectively produce, prior to intervention, accurate and high-resolution 3D models of a cave with engravings dating back to the Upper Palaeolithic era. The processing of the TLS data is discussed in detail in order to create digital surface models. The complexity of the cave required the integration of two techniques, TLS and close range photogrammetry to yield not only traditional drawings such as sections and elevations, but also photo-realistic perspective views and visual navigation worlds fully operational in 3D environments. This paper demonstrates the potential of integrating TLS and close range photogrammetry to provide both accurate digital surface models and photo-realistic outputs. This processed data can be used to systematically improve archaeological understanding of complex caves and relief panels of prehistoric art with tiny engravings.     

Towards a Risk Management and Conservation Plan for the Djin Blocks at the World Heritage Site of Petra,Jordan: The Case of Djin Block No. 9

Cultural heritage is subjected to many pressures and risks. Over the past few years, the use of digital technologies has significantly changed the approaches to cultural heritage documentation for the purpose of condition assessment and conservation. The integration of novel approaches and techniques has permitted a detailed examination and assessment of damage, deterioration due to weathering and erosion, and their mechanisms. This study seeks to contribute to the preservation and conservation of the significant heritage of the so-called Djin Blocks at the World Heritage Site of Petra in Jordan. While these three dimensional cuboid rock-cut monuments have been subject to extensive conservation studies, this is the first time they have been subjected to 3D recording and multispectral photography, with the aim of recording damage caused by the ravages of time.

This study presents the results of the documentation of the case study Djin Block No. 9. A variety of systematic documentation techniques were used, including 3D recording with terrestrial laser scanning (TLS), close-range photogrammetry, multispectral imaging, and thermography records. In addition, pathological studies of the erosion from various causes and an analysis of the effect of weathering on Djin Block No. 9 are performed. Based on this data, the paper presents recommendations for developing risk management and conservation planning of Djin Block No. 9.     

Archaeological Site Information Modelling and Management Based on Close-Range Photogrammetry and GIS

New challenges in management and restoration of archaeological sites require the utilization of advanced technologies and systems to assist in preserving the important legacy of human heritage. These challenges include monitoring and preserving of site landscapes, maintenance and rehabilitation of archaeological structures, and quality and safety management. In this research, an integrated methodology based on photogrammetry and Three-Dimensional (3D) Geographic Information System (GIS) is developed to capture and model essential details needed for the proper management of archaeological sites. Recent advances in digital imagery and modelling utilize photogrammetry as an efficient technique for 3D modelling of archaeological sites to derive accurate measurements of size, shape, position, and texture of objects using two-dimensional digital photographs. Spatial data that include aerial stereo photographs, satellite images, close-range photos, terrestrial surveying and Global Positioning Systems (GPS) are integrated within the design of the proposed model. The approach is validated with a case study of Ajloun Castle, one of the ancient and important preserved structures located in Jordan. Various sequential levels of details have been developed for the castle: Orthophoto, Digital Elevation Model (DEM), structures geometry and site layout and 3D textured model. The suggested methodology is expected to be efficient in modelling and documenting archaeological structures. The developed model is utilized to assess the management of archaeological structures through feasibility analysis, rehabilitation decisions, and safety planning.     

Terrestrial laser scanning intensity data applied to damage detection for historical buildings

This paper presents a methodology to combine the technology of the terrestrial laser scanner with the techniques of digital image processing in order to study damages on stony materials that constitute historical buildings. This methodology has been tested using intensity data from three terrestrial laser scanners with different technical specifications. The unsupervised classification algorithms were used for the classification of 2D intensity images derived from the 3D information obtained from laser scanner equipment. The results obtained show the potential of the use of intensity data from terrestrial laser scanner for the recognition and characterization of certain pathologies in building materials that constitute historical buildings.     

3D Digital Documentation,Assessment, and Damage Quantifi cation of the Al-Deir Monument in the Ancient City of Petra,Jordan

Abstract

The rock-cut monuments in the ancient city of Petra in Jordan form an outstanding tangible heritage site. Unfortunately, this important part of the world's cultural heritage is gradually being diminished due to weathering and erosion problems. In this research, an approach combining in situ surveying and laboratory analysis is applied in order to provide sufficient and comprehensive data regarding the documentation and evaluation of the status of the Al-Deir monument in Petra. The purpose was not only to quantify the damage, but also to make a first step towards creating a 3D monitoring programme of the deterioration rate. The approach presents a correlation study between the environmental condition and the surface weathering damage, using 2D mapping of the weathering form and accurate 3D realistic modelling from laser scanning and digital photogrammetry. The 2D mapping provides detailed weathering damage information for the entire stone surface of the monument, whereas the 3D modelling provides information on the spatial distribution and texture of the damage. Additionally, the 3D digital model can provide reference data as an exact guide to the restoration needed. In order to support the visual presentation of 3D surface details, a hybrid approach combining data from laser scanning and digital imagery was developed.

Studies of stone texture and spatial distribution of soluble salts were carried out at the monument in order to explain the mechanism of the weathering problem. Relative humidity, temperature, and wind are the main factors in the salt damage process. In order to study the effect of these conditions in the salt crystallization process a series of fieldwork investigations and laboratory work were undertaken. The results show that visible zoning of weathering damage is correlated to different salt concentrations.     

Inscribed landscapes in the Black Desert: Petroglyphs and kites at Wisad Pools,Jordan

Petroglyphs are well known in the Negev, eastern and southern Jordan, and the Arabian Peninsula. Intensive documentation of hundreds of petroglyphs at the site of Wisad Pools in the Black Desert of eastern Jordan records animals, humans, hunting traps and geometric designs, connecting people and places to the larger landscape. These were recorded at the landscape scale with drones and photogrammetry, and the local scale through the construction of a database combined with GPS recording and terrestrial photogrammetry. Petroglyphs of animals and hunting traps are significant because the site is located within a landscape that includes enormous and enigmatic hunting traps (desert kites). Mapping these depictions highlights typological distribution, association of types, and relation to landscape features as well as the topography of the basalt boulders on which they were pecked. The depictions of animals and hunting traps provide clues about the use of desert kites, the social role of hunting, communal gatherings, and feasting in the region.     

Capturing spatial patterns of rural landscapes with point cloud

Over the past few decades, rural landscapes have been the subject of increasing international cultural heritage research, and one of the most important issues under investigation at both theoretical and pragmatic levels concerns how to identify the spatial character of rural landscapes for conservation purposes. This article establishes an innovative approach adopting a cultural landscape perspective with the support of point cloud technologies to capture spatial patterns of rural landscapes. This approach was explored by reference to Tunpu villages in Guizhou, China—these being a specific kind of military fortress settlement. Cultural landscape values and landscape characters of Tunpu villages were identified using historical research and document analysis. Aerial and terrestrial photogrammetry and laser scanning systems were combined to collect and process spatial information at environmental, village, and architectural scales. Point cloud models can quantitatively represent villages' spatial patterns and inform the interpretation of their heritage significance. We conclude that the strengths of point cloud technologies could meet the requirements of rural landscape heritage documentation from a cultural landscape perspective. This mixed‐technology approach could also greatly improve the efficiency and precision of traditional rural landscape documentation, which has the potential to change methodologies applied to rural landscape research and management.     

Laser scanning for conservation and research of African cultural heritage sites: the case study of Wonderwerk Cave,South Africa

The ‘African Cultural Heritage and Landscape Database’ project, initiated and directed by the senior author and administered by Aluka (www.aluka.org), is aimed at the creation of a digital library of spatial and non-spatial materials relating to cultural heritage sites in Africa. The archaeological site of Wonderwerk Cave (South Africa) is one of the 19 sites documented to date using laser scanning, conventional survey, digital photogrammetry and 3D modelling. To date, it is one of the few archaeological caves worldwide to be fully scanned. This paper explores the different uses to which the spatial data derived from this cave have been, or will be, put – for historical and educational purposes, scientific research and site conservation and development.     

New tools for rock art modelling: automated sensor integration in Pindal Cave

This paper presents the integration of automated sensors based on a terrestrial laser scanner and an amateur digital camera with the aim of generating a photorealistic three-dimensional (3D) model of the Principal Panel in Pindal Cave (Spain). The approach developed for 3D modelling overcomes many of the problems related to the independent implementation of photogrammetry and laser scanning. Particularly, a sequential and hierarchical approach was developed based on the processing and matching of images from the camera (camera image) and the laser scanner (range image). The results obtained demonstrate that the workflow for this model is automatic, effective, and accurate. The presented approach was found to create hyper-realistic models, even improving upon human visual capabilities.     

Evaluation of Structure from Motion Software to Create 3D Models of Late Nineteenth Century Great Lakes Shipwrecks Using Archived Diver-Acquired Video Surveys

Here we demonstrate the ability to use archived video surveys to create photorealistic 3D models of submerged archeological sites. We created 3D models of two nineteenth century Great Lakes shipwrecks using diver-acquired video surveys and Structure from Motion (SfM) software. Models were georeferenced using archived hand survey data. Comparison of hand survey measurements and digital measurements made using the models demonstrate that spatial analysis produces results with reasonable accuracy when wreck maps are available. Error associated with digital measurements displayed an inverse relationship to object size. Measurement error ranged from a maximum of 18 % (on 0.37 m object) and a minimum of 0.56 % (on a 4.21 m object). Our results demonstrate SfM can generate models of large maritime archaeological sites that for research, education and outreach purposes. Where site maps are available, these 3D models can be georeferenced to allow additional spatial analysis long after on-site data collection.     

Experiencing Ancient Buildings from a 3D GIS Perspective: a Case Drawn from the Swedish Pompeii Project

In recent times, archaeological documentation strategies have been considerably improved by the use of advanced 3D acquisition systems. Laser scanning, photogrammetry and computer vision techniques provide archaeologists with new opportunities to investigate and document the archaeological record. In spite of this, the amount of data collected and the geometrical complexity of the models resulting from such acquisition processes have always prevented their systematic integration into a geographic information systems (GIS) environment. Recent technological advances occurred in the visualization of 3D contents, led us to overcome the aforementioned limitations and set up a work pipeline in which was possible to put the 3D models not only in the context of data visualization but also in the frame of spatial analysis. The case study described is a part of the Swedish Pompeii Project, a research and fieldwork activity started in 2000 with the purpose of recording and investigating an entire Pompeian city block, Insula V 1. As an additional part of the research, a laser scanning acquisition campaign was conducted in the last few years. The resulting models were thus meant to be used to develop further research lines: Among these, a 3D GIS system was expected to be set up with the purpose to (i) collect in the same geo-referenced environment, different typologies of documentation gathered in the context of the Swedish Pompeii Project; (ii) inter-connect 3D models with the project website; (iii) use the third dimension as a further analytical field of investigation, in the form of spatial analysis and cognitive simulation.     

Practical Application of Digital Photogrammetry for Fieldwork in the American Midwest: An Example from the Middle Ohio Valley

The use of close-range digital photogrammetry for field documentation has been steadily increasing in the past half decade in several parts of the world. However, this technology has not been widely utilized in archaeological contexts in the American Midwest. We explore the utility of close-range photogrammetry in this region with examples from the Guard site (12D29), a Fort Ancient village located in southeastern Indiana. This article outlines the methods utilized for production of georeferenced 3-D models of several units excavated during the 2016 field season. These models as well as plan and profile orthophotos derived from them act as important supplements to standard photographs and drawings made in the field and easily integrate with the site GIS. Overall, we found close-range digital photogrammetry to be very useful to better document excavation details, doing so for limited cost and time expenditure.     

Combining photogrammetry and laser scanning for the recording and modelling of the Late Intermediate Period site of Pinchango Alto,Palpa, Peru

This paper describes the 3D modelling of Pinchango Alto, Peru, based on a combination of image and range data. Digital photogrammetry and laser scanning allow archaeological sites to be recorded efficiently and in detail even under unfavourable conditions. In 2004 we documented Pinchango Alto, a typical site of the hitherto poorly studied Late Intermediate Period on the south coast of Peru, with the aim of conducting spatial archaeological analyses at different scales. The combined use of a mini helicopter and a terrestrial laser scanner, both equipped with a camera, allowed a fast yet accurate recording of the site and its stone architecture. In this paper we describe the research background, the 3D modelling based on different image and range data sets, and the resulting products that will serve as a basis for archaeological analysis.     

Toward Hybrid Modeling and Automatic Planimetry for Graphic Documentation of the Archaeological Heritage: The Cortina Family Pantheon in the Cemetery of Valencia

ABSTRACT

The current trend toward the hybrid methodology of combining terrestrial laser scanner (TLS) with close-range and UAV-assisted photogrammetry is becoming the most effective method for the complete capture of archaeological sites. In this article, we consider three objectives in this regard: first, to check an integration procedure, based on different capture techniques, to obtain the best possible complete digital model in different situations related to size, lighting, and occlusions. Second, a “laser scanning with the help of photogrammetry” strategy for the operation with the different data sources, which allows to adapt the processes of photogrammetric orientation, cloud registration, and automatic texturing, to the characteristics of each capture model. Finally, to present the digital edition of these models through automatic technical projections and realistic visualizations, to show their ability to interpret their geometry or share their knowledge, respectively.     

ORTHOIMAGE‐BASED DOCUMENTATION OF ARCHAEOLOGICAL STRUCTURES: THE CASE OF A MEDIAEVAL WALL IN PONTEVEDRA,SPAIN

During the completion of the expansion works at the Museum of Pontevedra (Spain), a stretch of about 60 m of the medieval walled enclosure surrounding the historic city centre was discovered. Due to its value as a heritage element, the discovery of this archaeological structure required the implementation of preservation activities and exhaustive documentation so that future generations will be able to know and enjoy this piece of history. This paper presents digital models that reproduce the original structure of the wall using close‐range digital photogrammetry, as well as orthophotos, which thoroughly document the dimensional and textural characteristics of the archaeological site. In addition to analysing the accuracy and validity of photogrammetry in the conservation of archaeological heritage, a methodology of data capture, processing and photogrammetry representation is evaluated.     

3D reality-based artefact models for the management of archaeological sites using 3D Gis: a framework starting from the case study of the Pompeii Archaeological area

This work describes the procedures, the different techniques and the pipeline used for creating a digital framework that should assist the Superintendence of Pompeii in the digital reconstruction, classification, management and visualisation of archaeological finds inside an advanced 3D web-based repository of reality-based data. Specific topics have been focused on the quality assessment procedures adopted to ensure consistency and reliability of data throughout the whole 3D models acquisition and pipeline creation, as well as on the particular semantic reality-based structure adopted to develop an information system into a knowledge one. The main purposes of our framework have been the usage of 3D digital models as a restitution of the real object and as a metaphor for navigating through the data; 3D models were used as archaeological cognitive systems and developed as a collection of structured objects, identified through a precise terminology that allows to easily extend the concept of 2D GIS to 3D GIS. In addition, the system was developed as a scalable application that allows the use of the same database by different users, simply filtering the data according to the specific requirements, and can operate both as standalone and web-based application.     

Three-dimensional (3D) visualisation: the application of terrestrial laser scanning in the investigation of historical Scottish farming townships

Recent developments in digital technologies are heralding significant changes in the way we acquire, visualise and analyse archaeological data. Terrestrial laser scanners can be used to create photo-realistic virtual copies of landscapes, and archaeological features, and offer the potential to improve our understanding of three-dimensional (3D) spatial relationships at study sites. Here we present a methodology for the integration of a high-resolution 3D site model with soil chemical data obtained from an abandoned settlement site located in the Central Highlands of Scotland. At this site, the multi-element concentration in soil, co-visualised within a topographic setting, has an important role to play in elucidating settlement layout and activity. The methods described here are also of significance in archiving sites of archaeological/historical importance where development activities and/or environmental processes may destroy remains, or where access to field sites is restricted.     

Agisoft Photoscan照片建模技术在考古中的应用

照片建模技术是指利用数码照片重建物体的三维模型的技术。和其他建模方法相比,Agisoft Photoscan照片建模技术的最大特点就是成本低,操作简单,整个建模过程由软件自动完成。在考古发掘过程中对遗迹现象、地层等拍摄数码照片,利用照片它能够快速、准确的完成三维数据模型的重建,真实的记录、保存大量发掘过程中的原始信息,便于再现不同阶段的发掘现场,也有助于遗存数字化信息的永久保存,为后续全方位的研究和虚拟化展示提供了充分保障。本研究将以洛阳定鼎门遗址博物馆前的小型建筑和一座墓葬为例,介绍Agisoft Photoscan重建遗物及遗迹3D数字模型的方法和流程以及在考古方面的应用。鉴于其对数据采集的高效性、简便的操作性以及快速建立遗迹三维数据模型的能力,在考古工作中将有着巨大的应用前景。     

From Hand Survey to 3D Laser Scanning: A Discussion for Non-Technical Users of Heritage Documentation

Abstract

Digital technology has changed our approaches to cultural heritage documentation radically and promises to continue to bring rapid changes. Photographic and non-photographic (graphic) documentation tools are merging in one process, in which digital photographic technology is the main base. Due to digital technology, there is an increasing gap between specialist technicians and non-technical users involved in heritage documentation. 3D approaches are still not popular among users in cultural heritage. However, in order to build a bridge between the specialist and non-technical users, a dialogue between them needs to be developed, not only to discuss issues of data precision and 3D accuracy, but also visualization production systems, which can now easily be achieved by modern digital photographic technology.

This paper presents a comparative evaluation and synthesis of cultural heritage documentation methods and survey techniques currently available, focusing on the needs and requirements of non-technical users of heritage documentation. It attempts to clarify some new aspects in cultural heritage documentation and to assess the impact of current technology. The paper undertakes a comparative evaluation of the potential application of digital methods in documentation — and examines issues such as quality, accuracy, time, costs and specific skills required — from pre-electronic techniques (hand measurement) to 3D laser scanning, which today represents the most advanced technology available for measuring and documenting objects, structures and landscapes.