Satellite Remote Sensing of Archaeological Vegetation Signatures in Coastal West Africa

This article discusses how archaeological sites in Sierra Leone, and by extension much of West Africa, can be identified through vegetation patterns (vegetation signatures) detectable in very high-resolution (VHR) multispectral satellite imagery. Settlement sites typically have a differing pattern of vegetation from the surrounding landscape, including concentrations of very large trees with sociocultural and historical significance: cotton (Ceiba pentandra) and baobab (Adansonia digitata). These features are conspicuous elements of the landscape both from the ground and in aerial imagery. Two complementary methods of using VHR multispectral satellite imagery are discussed in this paper: visual interpretation and semi-automated subpixel classification. These techniques are aiding ongoing archaeological survey of the Sierra Leone River Estuary. The impact of recently renewed industrial activity at a site of probable archaeological significance is also assessed through visually interpreted VHR satellite imagery.     

The Integration of VHR Satellite Imagery,GPR Survey and Boring for Archaeological Prospection at the Longcheng Site in Anhui Province,China

This paper is focused on the joint use of non‐invasive and minimal intervention techniques for supporting archaeological prospection. Very high resolution (VHR) satellite imagery analysis and ground‐penetrating radar (GPR) and boring surveys were integrated for the study of the Longcheng site, located near Hefei city in Anhui Province, China, to test their effectiveness and efficiency in prospecting archaeological remains and evaluating their degree of preservation. First, target locations of potential archaeological structures were identified on a WorldView‐2 (WV‐2) satellite image through spatial and radiometric enhancement, interpretation and object‐oriented classification. Second, archaeological features extracted from the WV‐2 imagery were further investigated by a GPR survey that provided detailed cross‐checking information about buried remains. Finally, a subsequent boring survey was conducted across those prospective archaeological structures in order to map the stratigraphic sequences on the basis of colour, compactness and the inclusions contained in the soil, and then to test their correspondence with the GPR data. The boring led to detailed confirmation of the results produced by the remote sensing analyses and GPR surveys, as well as the discovery of datable artefacts. On the basis of all the integrated data, the preliminary layout and structure of the Longcheng site was reconstructed in GIS. Furthermore, the widths, lengths, heights and burial depths of these buried archaeological structures were estimated in detail.     

Notice of Inscriptions and Antiquities,Discovered at Caerleon

This paper presents some of the background information considered necessary to expand the archaeological uses of aerial photography. Some problems encountered recording archaeological features from the air are discussed but the paper concentrates on the subsequent use of aerial photographs and covers the interpretation and plotting of archaeological features, use of different map scales, and outlines two schemes for the presentation of completed drawings which show air photograph evidence. The uses and potential of morphological analysis are included, as are comments on the relevance of fieldwork to air photograph interpretation.

An appendix considers the application of geophysical techniques to air photograph sites, and the deductions that may be derived from these non-destructive methods.     

Observatory validation of Neolithic tells (“Magoules”) in the Thessalian plain,central Greece,using hyperspectral spectroradiometric data

This paper presents the results obtained from field spectroradiometric campaigns over Neolithic tells (“magoules”) located at the Thessalian region in Greece. In each one of the four archaeological sites selected, three sections were carried out using the GER 1500 handheld spectroradiometer. Spectral profiles of the sections and several vegetation indices such as Normalized Difference Vegetation Indices (NDVI) and Simple Ratio (SR) have been examined in this study. This is one of the first times that ground hyperspectral data are evaluated in such context of archaeological research for the spectral characterization of archaeological features. As it was found, ground spectroradiometric measurements can be efficiently used in order to support and validate satellite imagery results for the detection of archaeological sites.     

The black layer of Middle Palaeolithic combustion structures. Interpretation and archaeostratigraphic implications

Certain aspects of the formation processes of simple, flat archaeological combustion structures such as those present in the Middle Palaeolithic record remain unexplained. Such kind of combustion structures are commonly affected by postdepositional agents and often, their only distinct, well preserved component is a thin black lens on the ground. Hence, understanding the nature of this black lens is essential towards archaeological interpretation. From an interdisciplinary microstratigraphic approach, we present a case study in which for an entire experimental series of flat combustion structures the black layer represents the fire-altered topsoil on which the fire was made. Parallel analysis of archaeological Middle Palaeolithic combustion structures from the site of El Salt (Alicante, Spain) reveal similar patterns, leading to significant implications for archaeological interpretation. In the light of these results, special attention must be paid to the formation processes of flat Middle Palaeolithic combustion features, as black layers and the material contained in them are not necessarily linked with combustion but with preceding activities or events. In such cases, black layers represent intact remnants of occupation surfaces, concealing significant behavioural and palaeoenvironmental information relevant to the reconstruction of Middle Palaeolithic societies.     

Optimum temporal and spectral window for monitoring crop marks over archaeological remains in the Mediterranean region

This paper aims to explore the formation of crops marks over archaeological features using remote sensing data. Crop marks are very important to archaeological research since they can reveal in an indirect way buried archaeological remains. Several researches have been able to locate subsurface relics via interpretation of multispectral and hyperspectral satellite images. However the best phenophase (time-window) where these crop marks are enhanced and which spectral bands are the most capable for this enhancement are still an open question for the scientific community. This study aims to address these fundamental aspects of Remote Sensing Archaeology. For this reason an extensive dataset was used: two control archaeological sites were constructed in two different areas of Cyprus (Alampra and Acheleia). In these areas both barley and wheat, were cultivated. In situ spectroradiometric measurements were taken over a whole phenological cycle (2001–2012) for both areas. More than 30 in situ campaigns were performed and more than 2600 ground measurements were collected. The phenological analysis of these measurements have shown that a period of only 15 days is best suitable for monitoring crop marks which is connected with one phenological stage; during the beginning of the boot stage of the crops. This period can be used in areas having similar climatic condition as Cyprus (Mediterranean region). Also as it was found, this phenological stage of crops might be also influenced by the climatic conditions of the area. The evaluation of a proposed Archaeological Index was performed at the Thessalian plain (central Greece), where several Neolithic settlements are established. The evaluation was made using both Hyperion and Landsat images. The results have shown that the proposed Archaeological Index is suitable for the enhancement of crop marks in satellite imagery.     

Near-Infrared Aerial Crop Mark Archaeology: From its Historical Use to Current Digital Implementations

Even though most archaeologists are aware of the crop mark phenomenon and its possible archaeological nature, the information on its occurrence and specific character is, in most cases, obtained by imaging in the visible spectrum. After the Second World War, the occasional use of near-infrared (NIR) sensitive emulsions attributed this kind of invisible imaging with a great potential. However, archaeological NIR imaging always remained restricted due to several reasons not, at least, its complicated workflow and uncertain results. This article wants to delve deeper into the subject, looking at the conventional film-based approach of NIR aerial reconnaissance and its historical use in archaeological crop mark research, after which a current straightforward digital approach will be outlined. By explaining the spectral properties of plants and using examples of recently acquired NIR imagery in comparison with visible frames, it should become clear why the detection and interpretation of crop marks can benefit from low-cost digital NIR imaging in certain situations.     

Surfaces from the Visual Past: Recovering High<Emphasis Type="Bold">-</Emphasis>Resolution Terrain Data from Historic Aerial Imagery for Multitemporal Landscape Analysis

Historic aerial images are invaluable sources of aid to archaeological research. Often collected with large-format photogrammetric quality cameras, these images are potential archives of multidimensional data that can be used to recover information about historic landscapes that have been lost to modern development. However, a lack of camera information for many historic images coupled with physical degradation of their media has often made it difficult to compute geometrically rigorous 3D content from such imagery. While advances in photogrammetry and computer vision over the last two decades have made possible the extraction of accurate and detailed 3D topographical data from high-quality digital images emanating from uncalibrated or unknown cameras, the target source material for these algorithms is normally digital content and thus not negatively affected by the passage of time. In this paper, we present refinements to a computer vision-based workflow for the extraction of 3D data from historic aerial imagery, using readily available software, specific image preprocessing techniques and in-field measurement observations to mitigate some shortcomings of archival imagery and improve extraction of historical digital elevation models (hDEMs) for use in landscape archaeological research. We apply the developed method to a series of historic image sets and modern topographic data covering a period of over 70 years in western Sicily (Italy) and evaluate the outcome. The resulting series of hDEMs form a temporal data stack which is compared with modern high-resolution terrain data using a geomorphic change detection approach, providing a quantification of landscape change through time in extent and depth, and the impact of this change on archaeological resources.     

Preparing an archaeological field survey: Remote sensing interpretation for herding structures in the Southern Levant

Development of archaeological “virtual surveys” using online satellite imagery allows the identification of an increasing number and diversity of data. Coherent procedures are now essential in the preparation of any field study: estimating archaeological potential, gathering and mapping environmental features, and building hypotheses about settlement location and settlement patterns. In this article, we propose methods aimed at developing tools to describe and measure the different elements of pastoral archaeological structures in southern Syria, and quantifying the importance of these structures in the landscape and natural environment. Our thematic case study is the pastoral settlement pattern in the Leja, a basaltic region in southern Syria.     

Detecting Late Holocene cultural landscape modifications using LiDAR imagery in the Boreal Forest,Susitna Valley,Southcentral Alaska

The subarctic boreal forest, or taiga, is the largest biome in the world but has received minimal archaeological research because of its remoteness and difficult working conditions. In Southcentral Alaska the most common archaeological sites are surface manifestations of proto-historic semi-subterranean caches once used for food storage and living structures. However, in dense summer vegetation, these small-scale features are difficult to locate without high intensity pedestrian survey. To test the usefulness of LiDAR data for archaeological prospection in the taiga, we compare LiDAR imagery to the known distribution of small-scale semi-subterranean cultural features. The use of LiDAR, when complemented with Sky-View Factor, has proven valuable in identifying relatively small semi-subterranean features though it does not replace on-the-ground investigation. Nevertheless, the application of LiDAR to locate low density and small-scale cultural features is widely applicable across the subarctic in densely vegetated contexts and may assist in significantly expanding our current knowledge of land-use patterns and site distributions in logistically challenging places.     

Satellite Remote Sensing Methods for Monitoring Archaeological Tells in the Middle East

Abstract

Using a variety of types of satellite imagery (SPOT, Corona, Landsat, and Quickbird) and concentrating on archaeological sites in the Egyptian floodplain, this paper proposes methods for monitoring the rate of archaeological site destruction in the Middle East. This image analysis shows how tells can be documented and monitored from computers anywhere in the world, emphasizing the multispectral capabilities and applications of satellites. The effects of population growth, looting, urban expansion, and war on archaeological sites in Egypt are reviewed, and a system is proposed to record sites by focusing on their individual spectral profiles. The analysis demonstrates how satellite imagery analysis can be applied to similar flood plain environments in Israel, Jordan, Syria, Turkey, Iran, Afghanistan, and Iraq.     

Statistical means for identifying hunter–gatherer residential features in a lithic landscape

Techniques are described for extracting circular rock features from landscapes dominated by clasts of the same type from which cultural features are composed, using as a test case a large stone circle residential site in western Wyoming, USA. Methods consist of point plotting all relevantly-sized culturally and naturally-deposited clasts in the field and identifying potential cultural features using point density analyses tools in ArcGIS. Potential rings are either accepted or rejected as cultural features by comparing clast frequency, density and distribution in internal, feature-ring, and external spatial buffers to ethnoarchaeological data recording stone circle size and morphology and to similar data generated from a control sample of off-site, naturally-occurring clasts. The results of the analysis are used to discuss group size, mobility type, and duration of site occupation and to explore problems of assessing such at surface archaeological sites resulting from palimpsest-type site formation processes.     

Towards a three-dimensional cost-effective registration of the archaeological heritage

Archaeological practice within the European context of heritage management is facing huge challenges in ways of recording and reproduction of ex-situ preserved sites. As a consequence of the Valletta-treaty, numbers of archived images and drawings of excavated structures as prime sources of past human activity, are exponentially growing. Contrarily to portable remains however, their future study and revision is biased by the two-dimensional character of the recorded data, rendering difficult their future reconstruction for new study or public dissemination. A more realistic three-dimensional (3D) way of recording and archiving should be pursued. In this paper the possibilities for 3D registration of archaeological features are examined in a computer vision-based approach using the PhotoScan software package (Agisoft LCC). It proved to be a scientific and cost-effective improvement compared to traditional documentation methods. Advantages can be found in the high accuracy and straightforwardness of the methodology. The extraction of an orthophoto or a Digital Terrain Model from the 3D model makes it feasible to integrate detailed and accurate information into the digital archaeological excavation plan. The visual character of 3D surface modeling offers enhanced output-possibilities allowing a better documentation of in-situ structures for future research and a higher public participation and awareness for the archaeological heritage.     

Heritage Management and Interpretation: Challenges to Heritage Site-Based Values,Reflections from the Heritage Site of Umm Qais,Jordan

The management of archaeological heritage is complex and problematic for site identity and local culture. Inattention to the array of values of heritage sites leads to the supremacy of a number of them and provides a controversy story of the archaeological site in question. Any heritage management and interpretation effort should correctly identify the different values of the site. Indeed, there is a need to manage and interpret the sites in a way to address the connection between the sites-based values and the associated and surrounding features. In current heritage management practice, values and values-based management are considered to be one of the most important approaches for the management of archaeological heritage. This study aims to understand how the values of the archaeological site of Umm Qais in northern Jordan can be adequately managed as both a natural and cultural landscape. At issue are conflicting views over the different values, their meaning and their uses by the different stakeholders. This research focuses on the ways in which these values are managed and interpreted to the public and whether it is done properly and in a fair manner. The fieldwork study led to a more complex understanding of how conflicting perceptions of values of Umm Qais as a national heritage site by the different stakeholders have affected implementation of management and interpretation projects. The results presented here indicate that the heritage management approach from the case study of Umm Qais focuses specifically on values associated with the physical archaeological aspect of the site, while those associated with the historic neighborhood of the site are neglected. The interpretation of the site has frequently focused on certain aspects of values at the expense of others. Information and insights gained from this study and specific suggestions for changing approaches are considered with regard to potential impacts on the management of the archaeological site and with regard to the public in general.     

Site Interiography and Geophysical Scanning: Interpreting the Texture and Form of Archaeological Deposits with Ground-Penetrating Radar

The remarkable potential of geophysical scanning—to assess the internal variability of sites in new ways, to highlight important phenomena in the field, to exercise co-creation of interpretation and commitment to minimal destruction of community partners’ resources, and to aid in the practice of due diligence in avoiding desecration of the sacred—continues to be underutilized in archaeology. While archaeological artifacts, features, and strata remain primary foci of archaeological geophysics, these phenomena are perceived quite differently in scans than in visual or tactile exposures. In turn, new registers of site exploration afforded by geophysical prospection may be constrained by the language of site excavation and visual observation, requiring adjustments in the ways of thinking about and describing what the instruments are measuring. The texture and form of site deposits as rendered in ground-penetrating radar scans can be examined in detail prior to making interpretations of cultural features or stratigraphy. Far more than simple “anomalies” demanding our attention for excavation, patterns in geophysical data can be the focus of extensive archaeological analysis prior to, in conjunction with, or independent from excavation.     

New discoveries in the Piramide Naranjada in Cahuachi (Peru) using satellite,Ground Probing Radar and magnetic investigations

The detection of buried earthen structures by using remote sensing techniques is still an open issue and a strategic challenge as crucial as it is complex. It is crucial because earthen archaeological remains are widely present thoughtout the world (in South America, Asia, Africa) and it is complex due to the subtle physical contrast between earthen remains and the surrounding subsoil.     

BUILDING AN IDENTITY: ARISTOCRATIC LANDSCAPE AND CONSPICUOUS CONSUMPTION AT THE 16TH‐CENTURY BISHOP'S PALACE IN ODENSE

In the 16^th century, establishing and maintaining one's status and position in society was an important social factor and motivator. This article examines to what extent such efforts can be deduced from archaeological material. The subject is the 16^th‐century bishop's palace in Odense, Denmark. This case study has been encouraged by the unprecedented large‐scale archaeological excavations that have taken place in the Odense city centre in recent years. The new archaeological data allows for a contextual analysis in which the finds and structures are considered as evidence for negotiated identity expressed through materiality. The main conclusion is that a unique socioeconomic identity is expressed in the building structure, while evidence from the portable objects is more ambiguous.     

Fortified Homesteads: The Architecture of Fear in Frontier South Australia and the Northern Territory,ca. 1847–1885

Abstract

This paper investigates the use of defensive architectural techniques by civilian settlers in frontier South Australia and the Northern Territory between ca. 1847 and 1885. Four sites were analysed, three of which are located in South Australia and one in the Northern Territory. This study takes a new approach to the archaeological investigation and interpretation of Australian rural buildings, one that identifies defensive strategies as a feature of Australian frontier architecture. These structures represent physical manifestations of settler fear and Aboriginal resistance. Over time, however, the folk stories attached to these structures have also come to play a significant part in Australia's frontier mythology. They are shown to form one component of a wider body of myths which serve the ideological needs of the settler society, justifying its presence by portraying the settlers as victims of Aboriginal aggression.     

A microarchaeological approach for the study of pits

Abstract

The study of the technology underlying pre-industrial storage structures has an interest from an anthropological and archaeological perspective, in terms of the evolution of key cultural and cognitive capabilities, often related to the transition to food production.

Microarchaeological techniques offer a unique perspective on the study of pre-industrial storing technologies. In this work, examples are presented from two archaeological contexts in different climatic and socio-ecological situations during the Holocene in S Asia and SW Europe. Microarchaeological techniques used in this study include micromorphology, Fourier transform infrared spectroscopy and phytolith analyses. The comparative study of two pits highlights key aspects of the decision-making process involved in technological solutions of storage: ? The choice of a location for the construction of a given storage facility is highly affected by contextual climatic, microclimatic, soil and bioturbative factors

? The time taken to consume stored foodstuffs seems to affect technological investment as much as the intrinsic conservation requirements of the stored taxa

? The use of fire to hygienise pits implies that such structures were not conceived for single use

? Pre-industrial storage systems can be seen as modular structures, which components (e.g. topographical location, sediment type, lining type, hygienisation techniques and cover) can be recombined to improve storage performance for different climatic settings and foodstuffs.

     

Three-dimensional image of seismic refraction tomography and electrical resistivity tomography survey in the castle of Occhiolà (Sicily,Italy)

A geophysical survey was carried out at the ruins of Occhiolà Castle (Sicily, Italy), a medieval village located at the north-western part of a hill named “Terravecchia” at 491 m asl. In order to map the archaeological structures (such as walls and burrows), Electrical resistivity tomography (ERT) and seismic-refraction tomography methods were used. The resistivity variations are known to correlate quite well with the lithology, thus providing important information for identifying the buried archaeological remains. On the other hand, seismic velocity variations provide information about the geometrical features of the remains. The two geophysical methods are used in an enjoined way to better aid the interpretation and evaluate the significance and reliability of the results obtained with each single method. The electrical and seismic data are displayed in three dimensions by using the iso-resistivity and iso-velocity surfaces, respectively. This allows us to effectively define the location of the anomalies present in the single electrical and seismic sections. The results obtained in the survey highlight the presence of structures of regular shape, probably due to features of archaeological interest.