Catálogo de publicaciones - libros

This chapter provides an overview of the rise of 3D technologies in the practice of maritime archaeology and sets the scene for the following chapters in this volume. Evidence is presented for a paradigm shift in the discipline from 2D to 3D recording and interpretation techniques which becomes particularly evident in publications from 2009. This is due to the emergence or improvement of a suite of sonar, laser, optical and other sensor-based technologies capable of capturing terrestrial, intertidal, seabed and sub-seabed sediments in 3D and in high resolution. The general increase in available computing power and convergence between technologies such as Geographic Information Systems and 3D modelling software have catalysed this process. As a result, a wide variety of new analytical approaches have begun to develop within maritime archaeology. These approaches, rather than the sensor technologies themselves, are of most interest to the maritime archaeologist and provide the core content for this volume. We conclude our discussion with a brief consideration of key issues such as survey standards, digital archiving and future directions.

Calibration of a camera system is essential to ensure that image measurements result in accurate estimates of locations and dimensions within the object space. In the underwater environment, the calibration must implicitly or explicitly model and compensate for the refractive effects of waterproof housings and the water medium. This chapter reviews the different approaches to the calibration of underwater camera systems in theoretical and practical terms. The accuracy, reliability, validation and stability of underwater camera system calibration are also discussed. Samples of results from published reports are provided to demonstrate the range of possible accuracies for the measurements produced by underwater camera systems.

This chapter explores the significance of legacy data as a source of new information and the possibility of extracting new information from sources of information that were recovered before the advent of computers and the digital revolution. Since then, much of the emphasis has been directed towards gathering new information and there has been little emphasis on records that date back over 50 years. This chapter examines two examples: the first the Cape Andreas Expedition in Cyprus 1969–1970 and the other the excavation 1977–1980. Both case studies are examined for the elements of photography that can be used to extract new information and how data, in the future, can be best be collected to suit these developments.

In September 1967 an important shipwreck site was discovered near the islet of Gnalić in Northern Dalmatia (Croatia). It immediately raised significant interest in the scientific community and the broader public. Due to logistical and financial issues, the excavation ceased after five short-term rescue research campaigns, over a total duration of 54 working days. Renewed interest in the site, particularly the hull remains, resulted in reviving the project after 45 years. The trial campaign, carried out in 2012, had a positive outcome, and the excavation has continued annually in a systematic way. The nature of the site demanded significant effort to document the excavated areas. Considering all the temporal restrictions caused by various reasons, photogrammetry proved to be an extremely helpful and efficient tool.

This chapter considers the application of underwater photogrammetry to record and document the underwater cultural heritage at the site of Anfeh in North Lebanon. Although photogrammetry has become a standard procedure in the field of maritime archaeology worldwide, this is the first use of this recording method in the country. The research context is presented, followed by the methodology adopted according to the particularities of the site and then the results of work undertaken over two campaigns: one in 2016 and one in 2017. The main aims in this chapter are to demonstrate the advantages of a low-cost and time-effective method of documenting sites, where the funding prohibits the use of more expensive geophysical equipment. The application of multi-image photogrammetry as a recording technique at Anfeh has merit in providing global access to artefacts in their in situ context. The results generated from 3D data were particularly informative to the study of a substantial collection of anchors of different types and sizes, without removing them from their underwater context. By calculating volume from the 3D scan, an estimation of the weight of these could be thus achieved and will serve in future analysis of the vessels plying the maritime routes at Anfeh.

In 2013, researchers affiliated with the South Australian Maritime Museum and University of Adelaide’s Australian Centre for Visual Technologies [ACVT] conducted an archaeological and laser scanning survey of the former Australian warship HMCS/HMAS . Between its launch in 1884 and service in the First World War, was substantially modified. Once decommissioned, the ship again underwent drastic changes. While several archival photographs exist that depict at various stages of its life, they provide only scant understanding of the transformative processes applied to ’s hull. Researchers at ACVT have developed methods of generating 3D models from archival photographs, and are using as a case study. Models have been created that depict the vessel at three specific periods of its service life, which in turn has enabled archaeologists to identify gradual variations to ’s hull that, in some cases, were so subtle they could not be discerned in existing archival photographs and other historic media.

The increased use of laser scanning and photogrammetry has given rise to new opportunities in disseminating information about historic maritime assets and are of great use in conservation management initiatives. This chapter discusses the current state of 3D survey of historic vessels and how this has been applied more recently for historic vessel conservation management. Key questions such as how this data is utilized, and what it is that the capture of such data is trying to achieve for the conservation and management of historic ships and vessels will be explored. In addition, this chapter will introduce information modelling, most commonly seen as Building Information Modelling (BIM) as an approach for furthering the effective management of historic ships and vessels, as well as other historic marine and maritime assets. It will demonstrate that the majority of attempts at utilizing BIM in the heritage sector have been limited to buildings, and that the full potential of this technique has not been realized. Through the use of the ‘VIM’ project at HMS the chapter will then explore how information modelling can be applied to a highly complex historic ship.

This chapter analyses the functionality and applicability of procedural computer-based modelling techniques in the field of nautical archaeology. To demonstrate this approach, an interactive procedural model of the lower hull timbers of a sixteenth-century European merchant ship was developed through a process of prototype implementation, and an evaluation of the usefulness and effectiveness of the prototypes developed was carried out using the timbers from the hull remains of the Belinho 1 shipwreck, found in Portugal in 2014. The 3D model was created using , a procedural node-based 3D software package. A basic collection of the main timber components of a ship’s lower hull was defined, and functional rules were created for each timber, based on real-world ship design and construction processes. Then the rules were incorporated into the logic of the procedural modelling algorithm, and the resulting model was changed by using the Belinho 1 shipwreck scantlings. The results, which will be discussed, were satisfactory, except for the planking, which is a very complex part of the shipbuilding process and deserves future attention.

This chapter introduces several state of the art techniques that could help to make deep underwater archaeological photogrammetric surveys easier, faster, more accurate, and to provide more visually appealing representations in 2D and 3D for both experts and public. We detail how the 3D captured data is analysed and then represented using ontologies, and how this facilitates interdisciplinary interpretation and cooperation. Towards more automation, we present a new method that adopts a deep learning approach for the detection and the recognition of objects of interest, amphorae for example. In order to provide more readable, direct and clearer illustrations, we describe several techniques that generate different styles of sketches out of orthophotos developed using neural networks. In the same direction, we present the Non-Photorealistic Rendering (NPR) technique, which converts a 3D model into a more readable 2D representation that is more useful to communicate and simplifies the identification of objects of interest. Regarding public dissemination, we demonstrate how recent advances in virtual reality to provide an accurate, high resolution, amusing and appropriate visualization tool that offers the public the possibility to ‘visit’ an unreachable archaeological site. Finally, we conclude by introducing the plenoptic approach, a new promising technology that can change the future of the photogrammetry by making it easier and less time consuming and that allows a user to create a 3D model using only one camera shot. Here, we introduce the concepts, the developing process, and some results, which we obtained with underwater imaging.

This chapter presents proof of concept results from a program of in situ experimental and shipwreck survey measurements using non-linear (parametric) sub-bottom profiler (SBP) acoustic technology. Currently adopted acoustic methods have practical limitations for in situ management purposes for underwater sites with buried archaeological material. Sidescan and multibeam sensors do not quantify material buried below the seabed; linear SBP surveys are challenging to operate in very shallow water and have difficulties with respect to interpretation in the top 30 cm of the seabed; and confidence estimates for parametric SBP depth of burial measurements have yet to be published. The prime purposes of this research, consequently, are: to quantify shallow buried archaeological sites in 3D with confidence estimates, by measuring the depth of sediment cover, thickness and lateral extent of buried archaeological material; and to investigate relationships between acoustic waveform parameters and the type and degradation condition of that buried material. This improved measurement and interpretation capability, when combined with the other geophysical search tools such as multibeam echo sounders and magnetometers, will also aid in the assessment of the archaeological research potential of underwater sites.