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Archaeological Prospection



Wiley Online Library : Archaeological Prospection



Published: 2017-10-01T00:00:00-05:00

 



Creating volume estimates for buried shell deposits: A comparative experimental case study using ground-penetrating radar (GPR) and electrical resistivity under varying soil conditions

2018-02-08T03:42:16.545713-05:00

Sampling issues represent a persistent problem in shell matrix research, particularly for large shell deposits. When small samples are taken from large buried deposits it is almost impossible, under current research practices, to understand how representative that sample is of the overall deposit. This case study tests a novel method for creating a better understanding of the buried deposits from which excavated samples are taken, thereby allowing for improved sampling strategies and a better understanding of how representative those samples are of the overall site. The case study employs two geophysical survey methods, ground-penetrating radar (GPR) and electrical resistivity, to investigate buried shell deposits under experimental conditions. The survey results were used to create volume estimations and three-dimensional (3D) models of buried shell deposits. This method is novel to shell matrix research and the current case study was designed to test the viability of the method under differing conditions. As well as testing the two geophysical methods, surveys were conducted under different moisture levels, soil types and survey transect spacings. Results showed that the 3D models and volume estimates of the deposit were successful in creating a representative understanding of the nature of the buried deposit, but with varying degrees of accuracy. GPR results created more accurate volume estimates and 3D models than the electrical resistivity results. Both geophysical methods produced more accurate results under drier conditions, though the electrical resistivity produced more visually distinct results with higher moisture levels. Analysis of the volume results revealed an error margin (to a confidence level of 95%) of 9.5% ± 15.5% for the GPR, and 44.5% ± 31.5% to 56 ± 70.5% for the electrical resistivity, depending on the interpretation method used to create the models.



Geophysical correlation: global versus local perspectives

2018-01-30T01:41:15.12746-05:00

Robust anomalies that point to the same buried features frequently occur in diverse data sets from multi-method surveys [e.g. ground penetrating radar (GPR), magnetic gradiometry, electrical resistivity]. Relationships between such corresponding anomalies traditionally have been noted subjectively, through visual comparisons of mappings or overlays of geophysical results. These circumstances create a paradox because theory and correlational studies generally suggest largely independent dimensions, while mappings of geophysical results often illustrate parallel anomalies which suggest that robust correlations should exist. Through application of local Pearson's r in small neighbourhoods, with radii ranging from 0.71 to 1.6 m, a means is offered, and demonstrated, to quantify and map local correlations between two geophysical data sets. A case study examines relationships between apparent electrical resistivity, a GPR depth-slice, and magnetic susceptibility data acquired at Army City, a Great War troop support town in Kansas, now obliterated except for subsurface remains. Intricate spatial patterns of positive and negative correlations between these modalities are illustrated that vary in complexity with neighbourhood size. Neighbourhoods of moderate size seem preferable because the spatial patterning of correlations is enhanced locally and region-wide. With focus given to positive correlations that point to parallel anomalies, overlays of high correlation frequently correspond with robust anomalies observed in each data set and offer objective criteria for assessments of correlation. However, it is also demonstrated that mutually robust anomalies do not necessarily exhibit high correlation and that high correlations frequently exist in regions devoid of apparent anomalies. The issue of assessing jointly parallel correlations between three or more geophysical data sets is also confronted using a form of local principal components analysis. It is shown that high eigenvalues associated with first principal components that exhibit loadings in the same direction point to zones of mutually high parallel correlation.



Virtual simulation of a late antique shipwreck at Marzamemi, Sicily: Integrated processes for 3D documentation, analysis and representation of underwater archaeological data

2018-01-18T22:00:04.644423-05:00

Three-dimensional (3D) models derived from digital survey techniques have increasingly become a mainstay of archaeological research and cultural heritage management. The high accuracy of such modelling makes it an attractive solution for a wide range of challenges from site recording and interpretation to object analysis and reconstruction. The present paper focuses on a new 3D digitization method using stereoscopic video for the documentation, analysis, and representation of archaeological contexts as part of shipwreck investigations off southeast Sicily at Marzamemi. This sixth-century ce vessel sank in shallow water (7–8 m) while carrying a massive cargo of largely prefabricated architectural elements intended for the construction and decoration of a church somewhere in the late antique west. This dynamic site presents significant challenges to the interpretation of depositional and post-depositional events as well the reconstruction of the original cargo and individual architectural elements. Therefore, 3D documentation underwater at Marzamemi has centred on new methods for stereoscopic scanning of the site, topography, and large architectural finds, allowing not only more rapid and precise mapping but insights into site formation processes and the organizational mechanisms behind the cargo assemblage. The adoption of this new system based on a precise workflow and simple, inexpensive hardware combined with readily available software allows more accurate and rapid digital recording underwater to a high standard across scales, from the site level down to the individual artefact. This process, named ISU3D (Integrated System for Underwater 3D Digitization), offers innovative solutions not only for archaeological field research but for heritage management and public outreach.



Unique performance of spaceborne SAR remote sensing in cultural heritage applications: Overviews and perspectives

2017-12-05T03:41:27.251988-05:00

To be an innovative remote sensing technology, spaceborne synthetic aperture radar (SAR) is increasingly recognized as an irreplaceable tool in cultural heritage applications, such as archaeological prospection for the discovery of new sites and monument monitoring and management, taking advantage of observation capabilities independent of sun illumination and weather conditions. In this paper, we firstly give a synoptic overview for the state-of-art of spaceborne SAR technology in cultural heritage applications. Then, the unique performance of SAR compared with optical approaches, including subsurface imaging and interferometry, is objectively exploited and assessed using simulations and case studies. Simulations indicated that long wavelength SAR is promising in the detection of relics with an extended geometric dimension, particularly when the performance of tomographic SAR (TomoSAR) in subsurface imaging is optimized. However, case studies proved that interferometic SAR (InSAR) is useful for landscape archaeology by producing digital elevation models as well as for risk monitoring and preventive diagnosis of cultural properties using motion indicators. This study showed the potentialities of spaceborne SAR applications in cultural heritage, with particular reference to TomoSAR and differential TomoSAR (D-TomoSAR).



Data processing chain for high spatial resolution magnetic survey: Application on the Neolithic site of le Pontet (Charente-maritime, France)

2017-11-09T23:21:29.062697-05:00

This article focusses on an original magnetic survey protocol and its data processing chain. The use of a high sensitive magnetometer combined with a motorized total station permits production of a magnetic map with a high spatial resolution and a high precision of magnetic and positional measurements. The data processing enhances the final magnetic map by the removal and restoring the outlier values, measurement errors and magnetic disturbances. The magnetic survey was undertaken on the Neolithic site of Le Pontet at Saint-Nazaire-sur-Charente (French Atlantic coast, between Bordeaux and La Rochelle). The site was chosen for geographical and archaeological characteristics such as its settlement period, the topography and the presence of different magnetic disturbances (proximity to roads and residential area). The data processing is mainly made on ungridded data and the gridding is the second to last step. The last step is to correct the relative height variation of the sensors between the prospecting lines (tracks) induced by the topography and operators. The use of a motorized total station allows accurate height determination of the sensors and an upward continuation is performed to correct the slight magnetic intensity variation induced by the relative height variation of the sensors. The results of the magnetic map bring out several causewayed enclosures, pits and postholes. This map will serve as a working basis for interdisciplinary studies and future archaeological studies of this site.



Some like it hot: The impact of next generation FLIR Systems thermal cameras on archaeological thermography

2017-10-12T21:51:11.668723-05:00

Infrared thermography, or thermal imaging, has been used as a remote sensing technique to determine whether subsurface features such as walls or pits generate a heat differentiation from the surrounding earth. To date, this form of remote sensing has been notoriously difficult to perform due to cost, low-resolution thermal cameras and an inability to provide a stable aerial photographic platform. Furthermore, thermal fluctuations produced by archaeological remains are highly volatile, and are dependent on a multitude of variables such as soil moisture, particle size, and the construction materials of features. These issues have restricted the use of infrared thermography within archaeology. Yet, with the rapid development and adoption of unmanned aerial vehicles (UAVs) over the last decade as well as developments in thermographic technology, thermal imaging is now affordable and can be attached with relative ease to a multitude of UAVs. This paper reviews a new, low-cost, FLIR Systems thermal camera made specifically for UAVs, which were successfully employed at the Ancient Methone Archaeological Project, Pieria, Greece. By utilizing the FLIR Vue Pro, along with a DJI Phantom 2, aerial thermography was performed at the site at a cost far below that proposed by previous studies, with results also equalling or exceeding those methodologies. In combination with high resolution aerial photogrammetry, this methodology has helped to clarify previous archaeological investigations at the site, as well as revealing significant rectilinear subsurface remains.



Mapping the Inhospitable Landscapes of the Orkney Islands using RPAS

2017-09-26T19:21:10.901094-05:00

This paper reports the outcome of the RPAS-based prospection of four prehistoric and early historic sites on Mainland, Rousay and South Ronaldsay Islands of the Orkney archipelago (Northern Scotland). Application of RPAS (Remotely Piloted Aircraft System) improved the effectiveness and accuracy of the mapping of the archaeological landscape, comparing to the ground-base survey. The paper presents the workflow used to obtain the low altitude images using RPAS and photogrammetric pipeline applied to create ortophotomaps and digital elevation models. Then the interpretation of mapped remnants at the sites of Brough of Deerness, Burrian, Hashwick and Burwick is discussed. Beside reporting the new datasets for the Orkney the author is clarifying the problem of surveying “the inhospitable” landscapes - the areas that for different reasons might be difficult to access by survey using ground-based methods. Therefore Remotely Piloted Aircraft Systems are advocated as a solution in such challenging conditions.



An application of integration approaches for archaeo-geophysical data: Case study from Aizanoi

2017-09-24T23:26:05.355565-05:00

Transforming multi-dimensional datasets, containing measurements of different physical parameters recorded at the same location, into a single composite imagery is quite important and frequently used in geophysical analysis as well as other scientific disciplines. This study focuses on the application of several different integration approaches for archaeo-geophysical data with a purpose of achieving complementary and improved information about the buried archaeological target by generating a single data set from multiple geophysical methods. An extensive geophysical survey using ground penetrating radar (GPR) and differential magnetic methods was made in different parts of the Aizanoi archaeological site (Cavdarhisar, Kutahya, Turkey) to locate and enhance subsurface archaeological structures. However, in this article, the outputs of graphical, mathematical and statistical integration approaches, which are applied both on synthetic images and real field case data, are presented and discussed. Comparing these results and experimental applications, mathematical and statistical integration approaches provide more useful and practicable information than just the single distinct datasets from each geophysical parameter studied.



Archaeological prospection of a specialized cooking-pit site at Lunde in Vestfold, Norway

2017-09-24T22:16:43.002235-05:00

In September 2010, an exceptionally large cooking-pit site was discovered by means of geophysical prospection at Lunde in Vestfold County, Norway. The site contains in excess of 1000 cooking-pits and is, to date, one of the largest of its kind discovered in Scandinavia. Features known as cooking-pits are ubiquitous on Northern European archaeological sites. Despite research spanning decades, however, the true function and role of this rather non-descript feature type is still debated. Using the results from geophysical prospection, soil analysis, ground-truthing and excavation, this article aims to better understand this phenomenon by evaluating the physical properties revealed from the data, and setting this exceptional site in a wider cultural-historical context. The wider, landscape context is accessible from the large-scale, high-resolution, landscape archaeological prospection case-study approach conducted by Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology (LBI ArchPro). The results suggest that the multi-method approach is essential in such cases, as it is able to challenge the assumptions of the blanket interpretations often applied, and put the site in a cultural and environmental context.



Use of LIDAR and photointerpretation to map the water supply at the Las Murias-Los Tallares Roman gold mine (Castrocontrigo, León, Spain)

2017-08-30T22:18:34.141231-05:00

A comprehensive study of the water supply at Las Murias-Los Tallares Roman gold mine (Castrocontrigo, León, Spain) was conducted using LIDAR technology and photointerpretation that revealed all-new and interesting aspects both as concerns the length of the channels and their structure and supply capacity. Although LIDAR technology proves to be very valuable and essential to analysing Roman hydraulic mining structures, there are various limitations when reconstructing supply systems due to the accuracy of LIDAR data and the deterioration of the structures after having been abandoned for nearly 2,000 years.



Terrestrial laser scanning and photogrammetry techniques for documenting fossil-bearing palaeokarst with an example from the Drimolen Palaeocave System, South Africa

2017-08-17T22:39:02.911187-05:00

This paper presents the results of a recent three-dimensional (3D) survey at the Drimolen Makondo palaeontological deposits in the Hominid Sites of South Africa UNESCO World Heritage site. The Drimolen Makondo is a palaeokarstic feature that consists of a heavily eroded 2.6-2.0 Ma fossil-bearing palaeocave remnant. With photogrammetry and a laser scan survey, two 3D site models were created, georectified, and imported into geographical information system software. This paper outlines both of these survey techniques and provides an assessment of the relevant merits of each method and their applicability for detailed recording and archival documentation of palaeokarstic palaeontological and archaeological sites. Given the complex depositional context of many of the fossil-bearing South African cave systems and their importance for understanding our evolutionary history, new methods are critical to visualising and analysing 3D spatial data. The utility of 3D models lies in their ability to integrate with total station survey techniques to accurately record and control excavations and provide a means of visualising stratigraphic, sedimentary, and spatial contexts in various geographical information system platforms. The use of low-cost and time-efficient digital photographic surveys to create accurate 3D models, if completed accurately, can provide researchers with a means of contextualising excavation data without the need for expensive and highly specialised equipment. The development of this method combined with differential global positioning systems provides a solution in more remote locations to recording highly accurate fossil and 3D site contexts with increasing ease. It also allows the sites to be recorded as part of an evolving landscape rather than as single isolated localities. This technique should be a standard technique implemented when working on irreplaceable UNESCO World Heritage sites such as the hominin-bearing caves of South Africa.



Issue Information

2017-12-03T21:32:09.604371-05:00

No abstract is available for this article.



Drones in Archaeology. State-of-the-art and Future Perspectives

2017-02-17T00:11:29.941166-05:00

In addition to traditional platforms for low-level remote sensing (balloons, kites, etc.) new and more complex automated systems [unmanned aerial vehicles (UAVs) or drones] have become available in the last decade. The success and market expansion of these platforms has been a driving force in the development of active and passive sensors specifically designed for UAVs. In the last few years archaeologists have started testing both platforms and sensors, particularly for the following applications: three-dimensional (3D) documentation of archaeological excavations; 3D survey of monuments and historic buildings; survey of archaeological sites and landscapes; exploratory aerial survey; and the archaeological survey of woodland areas. The scale of these applications has ranged from site-based to landscapes-based (approximately up to about 10 km2 in extent). The role of such platforms in the archaeological survey of excavations and landscapes, and in diagnostics more generally, is of great interest and is inexorably growing. Copyright © 2017 John Wiley & Sons, Ltd.



Reconstruction of a Palaeosurface and Archaeological Site Location in an Anthropogenic Drift Sand Area

2017-02-28T03:00:40.646207-05:00

Knowledge of the position of archaeological remains in the surface relief provides important basic information for archaeological survey design and interpretation. Geomorphological processes in (pre)history may have resulted in a modification of the local relief around archaeological sites, especially in areas that are prone to sediment erosion and relocation, such as sheet sand and dune landscapes. In this study, we reconstructed and analysed the palaeorelief of an archaeological excavation site in an inland dune area in southern Brandenburg, Germany. The remains of two Mesolithic sites were documented in the archaeological excavations and found to be associated with a buried soil horizon. To gather information on the relief of the buried soil surface, we used a combination of sedimentological and pedological profile descriptions along archaeological survey trenches and geophysical prospection with ground penetrating radar supplemented with microdrone photography and photogrammetry, global positioning system (GPS) surveys, and analysis of LiDAR-based elevation models. A digital elevation model of the buried surface was generated and analysed using a geographical information system (GIS). A comparison of the palaeosurface model with the recent surface elevation model shows that sand remobilization resulted in a considerable reshaping of the relief. Further, an analysis of the buried surface model shows that the relief position of the two archaeological sites in the study area was considerably more prominent in relation to the corresponding buried soil surface than in relation to the recent surface morphology. The results affirm the significance of Holocene sediment relocation for the local surface morphology and the importance of considering such relief modifications in archaeological surveys. Copyright © 2017 John Wiley & Sons, Ltd.



LiDAR-guided Archaeological Survey of a Mediterranean Landscape: Lessons from the Ancient Greek Polis of Kolophon (Ionia, Western Anatolia)

2017-04-25T23:31:37.510415-05:00

In 2013, an airborne laser scan survey was conducted in the territory of the Ionian city of Kolophon near the western coast of modern Turkey as part of an archaeological survey project carried out by the Mimar Sinan University of Istanbul (Turkey) and the University of Vienna (Austria). Several light detection and ranging (LiDAR) studies have been carried out in the temperate climate zones of Europe, but only a few in Mediterranean landscapes. Our study is based on the first LiDAR survey carried out for an archaeological purpose in Turkey and one of the first in the Mediterranean that have been planned, measured and filtered especially for archaeological research questions. The interpretation of LiDAR data combined with ground-observations proved extremely useful for the detection and documentation of archaeological remains below Mediterranean evergreen vegetation and dense maquis. This article deals with the methodological aspects of interpreting LiDAR data, using the Kolophon data as a case study. We offer a discussion of the strengths and limitations of LiDAR as an archaeological remote sensing method and suggest a best practice model for interpreting LiDAR data in a Mediterranean context. © 2017 The Authors. Archaeological Prospection published by John Wiley & Sons Ltd.



The GPR investigation of the Shakespeare family graves

2017-07-13T22:07:51.854469-05:00

As part of a multi-disciplinary programme of archaeological investigation, GPR was used to investigate the Shakespeare family graves below the chancel of Holy Trinity Church in Stratford, Warwickshire, England. Although William Shakespeare's place as perhaps one of the most famous individuals who has ever lived has been cemented in the annals of history, much of his life and death is still shrouded in mystery. As a result, a large number of myths and legends have grown up around his burial place. These included the suggestion of an unusually deep burial or the presence of a large family crypt beneath the chancel floor. A series of multi-frequency surveys was carried out to establish the depth and structure of the graves and as much burial information as possible. Close survey (using a strategy developed and successfully applied in Westminster Abbey and other churches) was used in order to optimise the quality of patterning in the data. Within Holy Trinity, this strategy was validated by the detection of a known vault. The use of multiple frequencies was critical in this investigation in order both to detect the graves and also to establish information about the graves. Too low a frequency may result in non-detection because of the relatively low target resolution whereas too high a frequency risks insufficient depth penetration. From this process a number of myths can now be discounted, including the presence of a large Shakespeare family vault or crypt. Instead, the GPR survey suggests that a simple, shallow, earth-cut burial lies beneath William's tombstone. One story however concerning disturbance of William Shakespeare's grave in order to remove his skull does correspond with the evidence.



Removal of sensor tilt noise in fluxgate gradiometer survey data by applying one-dimensional wavelet filtering

2017-06-15T02:51:14.737654-05:00

Archaeological prospection with magnetometer instruments is performed in a wide range of field configurations, ranging from single probe setups to mobile arrays that allow combining multiple sensors. The latter type, whereby instruments are mounted onto a cart system, are particularly prone to motion-induced noise. Sensor tilt, for example, causes in-line noise that can obscure magnetic variations present. To remediate these effects, image processing techniques are the most frequently applied. However, while efficient in producing more levelled data plots, these procedures are often associated with a smoothing penalty whereby low-intensity or small-scale anomalies are masked. We propose a one-dimensional signal processing approach, based on discrete wavelet analysis. By selecting wavelets that correspond to the motion-induced noise patterns, such effects can be targeted more precisely, reducing the risk of feature masking or artefact creation. Evaluation of the proposed procedure on three fluxgate gradiometer datasets collected with a hand-propelled push-cart system, proved it a valid and more dedicated method to reduce the impact of motion induced noise in magnetometry data collected with cart mounted array setups.



Geochemical insight during archaeological geophysical exploration through in situ X-ray fluorescence spectrometry

2017-06-15T02:50:58.182333-05:00

Geophysical techniques are widely applied in archaeological exploration, providing rapid and non-invasive site appraisal. Geochemical analyses contribute significantly in archaeometry, but conventional laboratory apparatus requires that samples are removed from their in situ context. Recent advances in field-portable apparatus facilitate in situ geochemical analysis, and this apparatus is deployed in this paper alongside conventional geophysical analysis to characterize the archaeological prospectivity of a site. The target is subsurface debris at the crash site of a World War II Mosquito aircraft. A 100 m long transect of magnetic, electromagnetic (EM) and in situ X-ray fluorescence (XRF) measurements was acquired in November 2014, with soil samples also collected for laboratory validation. A subset of XRF measurements was repeated in August 2015 alongside a targeted grid, 900 m2 in area, of magnetic gradiometry profiles. Built chiefly from wood, the Mosquito responds weakly in magnetic and EM data; magnetic gradient anomalies of ±10 nT/m are instead attributed to thermoremanence in a burnt layer at 0.2–0.4 m depth, produced by the impact fire following the crash. XRF spectrometry reveals co-located enrichments in copper (Cu) and zinc (Zn) ions (400% and 200%, respectively, above background). These metals are alloyed into brass, present in abundance in the ammunition on board the Mosquito. Records from the in situ XRF sampling compare well with laboratory validated data, although a bespoke calibration for the local soil type would improve the reliability of absolute geochemical concentrations. XRF responses vary significantly with ground conditions: the November 2014 acquisition was performed soon after ploughing at the site, potentially providing a fresh charge of metallic contaminants to the ground surface. Where the chemistry of a target is anomalous with respect to host soil and a source-to-surface transport mechanism is present, in situ XRF analysis offers improved understanding of a target compared to geophysical interpretation alone.



Large-scale geophysical archaeological prospection pilot study at Viking Age and medieval sites in west Jutland, Denmark

2017-06-28T03:30:40.230939-05:00

In 2014, a team of the Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology, in collaboration with Holstebro Museum, conducted a geophysical archaeological prospection pilot study at several Viking Age and medieval sites in West Jutland, Denmark; sites that had been discovered earlier by aerial archaeology. The high-resolution surveys employed motorized ground-penetrating radar (GPR) and magnetometer systems as well as novel post-processing software. The aim of this study was to test the suitability of these methods and the chosen approach to efficiently explore, investigate and document prehistoric settlements on a large scale under the prevalent environmental conditions in this part of Denmark. Over the course of five days of fieldwork, numerous structures of archaeological interest, such as the remains of longhouses, property boundaries, pathways, pit houses and other buried remains of the settlements, were detected and mapped. The combination of the data gathered by magnetic and GPR prospection with the already existing aerial imagery permitted an integrated archaeological interpretation, resulting in considerable new knowledge about the investigated sites. In this paper, we present the results obtained for the Viking Age settlement at Stadil Mølleby and a medieval village near Rysensten, both situated on sandy soils.



Enhancing signals from buried Roman structures in Magnetometer data by combining continuous wavelet transform and tensor voting

2017-07-26T02:42:32.241922-05:00

In this paper, a processing chain is proposed for enhancing larger-scale building structures in magnetometer data using the continuous wavelet transform for extracting the horizontal location, depth, and homogeneity (or shape) of subsurface objects. Even though the values estimated from our data do not clearly describe the archaeological site, they are used as a filter step for removing objects whose depth and homogeneity fall outside a predefined range. This yields a binary map, where valid points represent the horizontal source positions of magnetic anomalies. In a second step, curvilinear subsets of points are identified on a larger scale by the tensor voting framework indicating archaeological relevant structures, such as arcs and lines. Here, a point casts votes on neighbouring points and their values depend on the distance, and relative position of the points. All votes are summed up and the final value discriminates, whether a certain point (and therefore a magnetic source) is part of a salient curve (e.g. arc, line). Thresholding removes points with lower values while keeping those with larger values. Although the result shows many geometric features, it still needs to be combined with other data, e.g. from aerial photography or excavations. In combination, the extracted features continue those structures in the aerial photograph, thus expanding the knowledge about the archaeological site.



A pixel-based semi-stochastic algorithm for the registration of geophysical images

2017-07-12T19:51:19.911981-05:00

The availability of overlapping geophysical data produced by different sensors provides complementary information about the investigation area. However, joint interpretation of these geophysical images is challenging. One common problem is the registration of the images that is necessary to compare features appearing in dissimilar datasets. Measurements in archeological geophysics are often performed by handheld devices therefore, the actual location of the measurement could be different from the planned one. These offsets are localized and essentially random. Consequently, it is impossible to correct them following usual deterministic approaches. This paper presents a novel registration method between geophysical images produced from different prospecting methods. We developed a semi-stochastic, iterative registration algorithm that applies random local transformations in small randomly selected regions of the processed image. The algorithm uses the mutual information of the images as similarity measure due to its suitability in images of different modalities. We use a pair of images to train the algorithm and tune its parameters. Afterwards, we test the method with nine different pairs of geophysical images from various locations and characteristics. The results, in all cases, show a significant increase of the mutual information in comparison with the registration through geographical coordinates.



Geoarchaeological evaluation of ground penetrating radar and magnetometry surveys at the Iron Age burial mound Rom in Norway

2017-07-12T19:56:49.747578-05:00

Following magnetometry and ground penetrating radar surveys, a geoarchaeological field evaluation was carried out at the Iron Age burial mound of Rom in Slagendalen, Vestfold County, Norway, in order to assess the accuracy of the geophysical data interpretation and to investigate specific questions that have arisen during data interpretation. The evaluation was conducted within the framework of an archaeological excavation campaign in 2013, which enabled direct access to the subsurface materials. The archaeological stratification was recorded by laser scanning using a three-dimensional (3D) single-surface approach, permitting a virtual reconstruction of the excavated part of the mound and facilitating the comparison between excavation and prospection data. Selected sediment sequences were targeted with in situ and laboratory-based measurements for correlation purposes, including magnetic susceptibility, electrical conductivity and water content measurements. Here we present the methodological approach and the results of the geophysical prospection surveys, followed by a geoarchaeological evaluation and a discussion of the impact on the overall archaeological investigation.