Integrated Geophysical Study of Archaeological Sites in the Aquileia Area

Integrated remote sensing and geophysical methods can provide detailed information about buried cultural heritage. We implemented an integrated survey protocol (IREGA, Integrated REmote-sensing and Geophysical prospecting for Archaeology) and tested the performance of the method in the area of the ancient Roman town of Aquileia, NE Italy, to define and characterize microareas of archaeological interest starting from macro-area observations. We used electromagnetic (GPR; ground-penetrating radar), magnetic and remote sensing (MIVIS; Multispectral Infrared and Visible Imaging Spectrometer) to image and characterize buried targets of potential archaeological interest in the depth range between 100 and 350 cm. We identified various geometrically coherent anomalies, possibly related to subsurface structures, through MIVIS data processing and found them in good agreement with the elements reported in the Aquileia archaeological map obtained from documentary evidence and excavations performed in the last century. Ultra High Resolution (UHR) Multi- Fold (MF) Ground-penetrating Radar (GPR) and magnetic surveys confirmed the MIVIS results and allowed imaging and mapping of buried structure related to different Roman remains (SE sector of the Circus, harbor and residential buildings foundations, roads)

ARCTIS — A MATLAB® toolbox for archaeological imaging spectroscopy

Imaging spectroscopy acquires imagery in hundreds or more narrow contiguous spectral bands. This offers unprecedented information for archaeological research. To extract the maximum of useful archaeological information from it, however, a number of problems have to be solved. Major problems relate to data redundancy and the visualization of the large amount of data. This makes data mining approaches necessary, as well as efficient data visualization tools. Additional problems relate to data quality. Indeed, the upwelling electromagnetic radiation is recorded in small spectral bands that are only about ten nanometers wide. The signal received by the sensor is, thus quite low compared to sensor noise and possible atmospheric perturbations. The often small, instantaneous field of view (IFOV)—essential for archaeologically relevant imaging spectrometer datasets—further limits the useful signal stemming from the ground. The combination of both effects makes radiometric smoothing techniques mandatory. The present study details the functionality of a MATLAB®-based toolbox, called ARCTIS (ARChaeological Toolbox for Imaging Spectroscopy), for filtering, enhancing, analyzing, and visualizing imaging spectrometer datasets. The toolbox addresses the above-mentioned problems. Its Graphical User Interface (GUI) is designed to allow non-experts in remote sensing to extract a wealth of information from imaging spectroscopy for archaeological research. ARCTIS will be released under creative commons license, free of charge, via website (http://luftbildarchiv.univie.ac.at)

Nuove tecnologie a supporto della ricerca archeologica: applicazioni e sviluppi possibili su sistemi complessi

INTRODUCTION. In the last two decades ground-based geophysical techniques have gained a prominent role in archaeological research projects thanks to ability to localize underground structures or geological body by measuring the variation, or anomalies, of physical properties existing between them and the hosting materials. When applied in archaeology geophysical surveys can reveal the location of buried archeological features and lead to their identification. However, the effectiveness of geophysical techniques applied in archeology is closely linked to the nature and the level of complexity of the buried deposit. If these techniques are used in sites characterized by multi-layered or strongly altered deposits, the survey results may be impaired, severely limiting their contribution to the historical and archaeological reconstruction of the investigated site. AIM OF THE STUDY. This research project has set two main objectives: i) to evaluate the potential of geophysical prospecting in extracting information in deeply stratified archaeological sites and ii) to test their effectiveness in a contemporary urban setting. MATHERIAL AND METHODS. The main geophysical technique applied was the Ground Penetrating Radar (GPR). The surveys were carried out using different systems (SIR 3000 GSSI and RIS Hi-Mod IDS) with antennas at different frequencies (from 200 MHz to 900 MHz). GPR data sets have been collected along closely spaced parallel profiles (0.25 to 0.125 m). Data were analyzed using different display methods: radargrams, amplitude depth-slices and three-dimensional models of isosurfaces. GPR data have been merged with historical and archaeological data (vector map of archaeological survey, Digital terrain Models - DTM, historical documents and historical maps) in a Geographic Information System (GIS) with ArcGIS software. ArcGIS is able to import the results of GPR surveys in raster format (amplitude depth-slices) and as three-dimensional models in Multipatch format. Data can be associated with attribute tables and the ArcScene module allows to display them three-dimensionally. Four sites in the historical center of Padua were studied integrating into a GIS the results of GPR surveys with historical and archeological data, two inside religious buildings (the Cathedral and the Church of the Eremitani) and two open areas who insisted on the structures of the ancient palace of the Carraresi. The other case study, focused on the integration of stratigraphic data obtained from archaeological excavations, with those of the geophysical surveys, was carried out in the Roman city of Aquileia (UD). RESULTS. The integration of the GPR survey of the Cathedral with the available historical maps allowed to recognize the position of a group of tombs that belonged to the previous Romanesque cathedral. It was possible to assume the position of the aisles of transept and of the crypt of the old building. The analysis of the isosurfaces model allowed to hypothesize the presence of a vaulted roof in burials identified below the existing pavement of the Eremitani Church. Moreover, the integration of data about burial distribution in the GIS was consistent with the possible presence in the church of a rood screen demolished in the sixteenth century. In both cases, the two GPR surveys revealed a reduced signal penetration (1-1.2m) and did not allow to identify the remains of walls linked to previous structures. The investigations carried out at the square in front of the Cathedral allowed to relate a series of walls with a complex of buildings dating from XI to XVIII century, when GPR data were compared with historical and archeological data in a GIS. The surveys performed in the palace of the Carraresi showed the presence (and state of preservation) of some portions of the XIV century complex. The same survey identified some previous structures, perhaps dating back to the Roman period. Finally, it was developed a rapid and effective approach for ground-truthing geophysical survey anomalies in the survey done in the Roman city of Aquileia. Moreover, the developed approach could assess the level of resolution of GPR survey by comparing the three-dimensional models of isosurfaces with a DTM from the excavation site obtained with the Structure from Motion technique - SFM

Remote Sensing and Geosciences for Archaeology

This book collects more than 20 papers, written by renowned experts and scientists from across the globe, that showcase the state-of-the-art and forefront research in archaeological remote sensing and the use of geoscientific techniques to investigate archaeological records and cultural heritage. Very high resolution satellite images from optical and radar space-borne sensors, airborne multi-spectral images, ground penetrating radar, terrestrial laser scanning, 3D modelling, Geographyc Information Systems (GIS) are among the techniques used in the archaeological studies published in this book. The reader can learn how to use these instruments and sensors, also in combination, to investigate cultural landscapes, discover new sites, reconstruct paleo-landscapes, augment the knowledge of monuments, and assess the condition of heritage at risk. Case studies scattered across Europe, Asia and America are presented: from the World UNESCO World Heritage Site of Lines and Geoglyphs of Nasca and Palpa to heritage under threat in the Middle East and North Africa, from coastal heritage in the intertidal flats of the German North Sea to Early and Neolithic settlements in Thessaly. Beginners will learn robust research methodologies and take inspiration; mature scholars will for sure derive inputs for new research and applications