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Looting is the major source of artefacts for the antiquities market. Specific measures are needed to fight the whole chain of the illicit activities undertaken by criminal organizations (from the excavation to the selling of the artefacts), and they should be devised for each phase of such illegal activities. The development and use of appropriate technologies for the identification of the most 'vulnerable' sites, and the timely detection and automatic quantification of the extension of the looted areas are crucial steps for setting up a monitoring system working also for remote and inaccessible archaeological areas, often in regions affected by armed conflicts or characterized by flight restrictions. In this context, Earth Observation (EO) technologies can provide reliable information: (i) to quantify the looting phenomenon even if it is on an 'industrial scale' over large areas, and (ii) to set up a systematic monitoring tool to trace the illicit trade in antiquities. In this paper, an improvement of the Archaeological Looting Feature Extraction Approach (ALFEA) -developed by the same authors in 2018-is proposed to further improve the ability in the automatic identification and extraction of looting features for heterogeneous desert landscapes, characterized not only by looting patterns but also by archaeological micro-relief and emerging remains, as well as by natural geomorphological features and the presence of structures and dirt pathways, which exhibit a similar spectral behavior but dimensions, morphology, and/or geometric patterns different from those linked to looting. The improvement of ALFEA (ALFEA-I) was applied in significant test areas considered among the most important archaeological sites in Peru, (i) Pachacamac close to Lima, and (ii) Ventarron in the Lambayeque region Northern Peru. The first site is characterized by past clandestine excavations and looting is difficult to recognize both in situ and from satellite image; the second site is affected by more recent archaeological disturbances due to grave robberies, easier to identify from remote sensing data. The original ALFEA -composed of the sequential integration of spatial autocorrelation statistics, unsupervised classification, and segmentation-has been herein refined by adding a processing step based on multi-threshold parameters of segmentation, thus improving the performance in terms of extraction capability of looting features in case of heterogeneous areas. Tthe integration of satellite based data processing with unmanned aerial vehicle (UAV) based close range acquisitions has proved to be effective in enhancing the visibility of old looting features, crucial for the validation of ALFEA-I. [ABSTRACT FROM AUTHOR]

Archaeological prospection of earthen buried structures, namely non-fired sun-dried mud bricks mixed with organic material, is a critical challenge to address. In fact, this building material exhibits a very low geophysical contrast compared to its surroundings and, therefore, earthen structures are very complex to be identified using remote sensing. In order to cope with this issue, in this paper, we focus on the evaluation of satellite X-band radar data (COSMO-SkyMed) capability for detecting earthen buried structures in a desert area. The results obtained from satellite radar data have been validated for a test site in Pachacamac (Peru) by using unmanned aerial vehicle (UAV) and geomagnetic techniques. The test site is outside the fenced protected zone of Pachacamac, today in the tentative UNESCO list. This paper is the first attempt made until now in evaluating the detectability of earthen archaeological remains using satellite Synthetic Aperture Radar (SAR) data. Outcomes from our investigations clearly point out that the approach we adopted can be useful applied for preventive archaeology and for the planning of future excavation campaigns. [ABSTRACT FROM AUTHOR]

ABSTRACT The processing method based on synthetic aperture radar (SAR) amplitude information presented by Cigna et al. (2013, this issue) was used to extract the backscattering coefficient ( σ0) from ENVISAT advanced SAR (ASAR) scenes to investigate the archaeological heritage of the Nasca region, southern Peru. Average backscattering and σ0 time series in 2003-2007 were obtained for some of the most famous groups of the Nazca Lines, as well as for the adobe structures of the Ceremonial Centre of Cahuachi, and allowed the recognition of anthropogenic features on arid and bare soil. Despite the expected constraints due to the medium spatial resolution of the ASAR scenes (~30 m), some features related to the Nasca ancient aqueduct systems ( puquios) were detected, and water level changes were inferred from amplitude change detection maps and σ0 time series. The SAR-based prospection results were also compared with a vegetation index derived from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data for 2003, 2004 and 2007. The changes observed over Cahuachi and the neighbouring archaeological mounds are then discussed in light of the recent conservation history of the site and the contemporary archaeological excavations. The research opens interesting perspectives for routine use of SAR data for purposes of archaeological prospection and condition monitoring in (semi-)arid and desert regions. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: 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. This paper presents the results from investigations based on Very High Resolution (VHR) satellite imagery (2002, 2005, 2008), geomagnetic surveys (November 2008) and Ground Probing Radar (GPR) (April 2008), we conducted on a mound named Piramide Naranjada. It is located in Cahuachi (Nasca, Southern Peru), the largest adobe Ceremonial Centre in the World. The studies were performed on two sides of this pyramid: (i) North-Eastern side, not yet excavated, using satellite data and magnetic prospection; (ii) and Eastern side using GPR to support the ongoing excavation activity. In the North-eastern side, results from the analysis of satellite images allowed the identification of shallow and outcropping adobe (earthen material) walls related to terraced platforms which compose the trunk-pyramidal structure of the Piramide Naranjada. These archaeological features were further investigated by high resolution geomagnetic surveys. The gradiometric maps enabled the identification of magnetic anomalies with different shapes: (i) linear shape features linked to buried, shallow and outcropping walls (the latter two already detected from the optical dataset); (ii) and circular shape anomalies linked to tombs and ceremonial offerings. In the Eastern side, where the excavations are in progress, radargrams allowed the discovery of a rich ceremonial offering made up mainly of ceramics, textiles, and painted pumpkins. [Copyright &y& Elsevier]

This paper is focused on the jointly use of satellite Quickbird (QB) images and Ground Probing Radar (GPR) for assessing their capability in the detection of archaeological adobe structures (sun-dried earth material). Such detection is particularly complex. due to the low contrast generally existing between the archaeological features and the background. Two significant test areas were investigated in the Ceremonial Centre of Cahuachi (in the Nasca territory, Southern Peru) dating back to 6th century BC to 4th century AD. Our results showed that both satellite and GPR data provided valuable indications for unearthing precious ancient remains. Our preliminary analyses pointed out that the integrated use of non destructive remote sensing techniques has high potentiality for its important scientific implications and for its significant contributions to cultural resource management. [ABSTRACT FROM AUTHOR]

One of the most complex challenges of heritage sciences is the identification and protection of buried archaeological heritage in urban areas and the need to manage, maintain and inspect underground services. Archaeology and geophysics, used in an integrated way, provide an important contribution to open new perspectives in understanding both the history of cities and in helping the decision makers in planning and governing the urban development and management. The problems of identification and interpretation of geophysical features in urban subsoil make it necessary to develop ad hoc procedures to be implemented and validated in significant case studies. This paper deals with the results of an interdisciplinary project in Cusco (Peru), the capital of Inca Empire, where the georadar method was applied for the first time in the main square. The georadar method was successfully employed based on knowledge of the historical evolution of Cusco and the availability of archaeological records provided by some excavations nearby the study area. Starting from a model for the electromagnetic wave reflection from archaeological structures and pipes, georadar results were interpreted by means of comparative morphological analysis of high amplitude values observed from time slices with reflectors visualized in the radargrams. [ABSTRACT FROM AUTHOR]

Traditionally the history of remote sensing began during the First World War when aerial photography became a valuable reconnaissance tool. However, moving back more than a thousand years, the real pioneers of remote observation were probably the Nasca, a pre-Hispanic civilization living in southern Peru, between 100BC and 700 AD. They used 'earth observation' as a mean of cultural expression drawing the geoglyphs (known as Nasca Lines) only visible from above. These drawings were made on flat desert surface of the Pampa by removing or clearing sand or stones, to create paths for ritual functions to please the gods and create harmonious relationships between man and environment. In this paper, the Nasca geoglyphs in Pampa de Atarco, are object of remote sensing based investigations with the twofold aim to identify and characterize them as well as to analyse and monitor their fragile state of conservation, threatened mainly by vandalism and off road vehicles. The approach herein proposed includes the integration and reuse of diverse remote sensing dataset, from multispectral satellite to Unmanned Aerial Vehicle (UAV) based LSAR data and close range photogrammetry. In particular, a multidate (2002–2013) very high resolution (VHR) optical satellite dataset has been processed in the spatial and temporal domain using textural indicators, including Skewness, Principal Component Analysis (PCA), and automatic classification tools which allowed us to enhance the visibility of disturbance features and to automatically extract them. The best results in terms of enhancement and automatic extraction capability of disturbance features have been obtained by Skewness. Moreover, the reuse of UAV L SAR-based correlation map, available free of charge from NASA, provided useful information on the state of disturbance from 2013 to 2015, widening the observation time window of the VHR satellite data set from 2002 to 2013. Finally, the integrated use of satellite VHR data with UAV-based photographs and DTMs, processed using structure from motion (SfM), allowed us to characterize, identify and reconstruct the relative chronological sequence of geoglyphs thus providing new insights and opening new perspectives for archaeological studies. • Exploring the past using the integration of satellite, aerial and UAV data. • Towards an operation satellite based monitoring of Nasca lines. • Automatic classification of changes due to human induced disturbance. • Relative chronology of execution phases of geoglyphs. [ABSTRACT FROM AUTHOR]

Abstract: For thousands of years, people throughout the world have built homes, communities and temples using earth materials, mainly in arid and semi-arid lands where generally other building materials were quite scarce. In the arid regions of Peru, from the 3rd millennium B.C. to Inca age, several civilizations shaped sand, clay and water into bricks (known as adobe) to build ceremonial centres, pyramids and towns. The detection of adobe archaeological buried remains by means of remote sensing techniques is a challenge as difficult as engaging, since the adobe has a composition quite similar to the neighbouring earth material. In this paper, Very High Resolution (VHR) satellite imagery have been used to identify archaeological features linked to the presence of shallow and outcropping adobe structures in some test sites selected from within the Ceremonial Centre of Cahuachi (Southern Peru). Both vegetated and non-vegetated areas were investigated. The promising results we obtained pointed out that the use of Earth Observation (EO) technologies can open new perspectives to detect adobe settlements. [Copyright &y& Elsevier]

Abstract: Illegal excavations represent one of the main risks which affect the archaeological heritage all over the world. They cause a massive loss of artefacts but also, and above all, a loss of the cultural context, which makes the subsequent interpretation of archaeological remains very difficult. Remote sensing offers a suitable chance to quantify and analyse this phenomenon, especially in those countries, from Southern America to Middle East, where the surveillance on site is not much effective and time consuming or non practicable due to military or political restrictions. In this paper we focus on the use of GeoEye and Google Earth imagery to quantitatively assess looting in Ventarron (Lambayeque, Peru) that is one of most important archaeological sites in Southern America. Multitemporal satellite images acquired for the study area have been processed by using both autocorrelation statistics and unsupervised classification to highlight and extract looting patterns. The mapping of areas affected by looting offered the opportunity to investigate such areas not previously systematically documented. To this purpose Ground Penetrating Radar prospections were conducted in some looted sites. [Copyright &y& Elsevier]

Abstract: An analytical protocol based on the combined use of the portable PIXE-alpha (Particle Induced X-ray Emission) and XRD (X-ray Diffraction) non destructive techniques developed at the LANDIS laboratory (Laboratorio di Analisi Non Distruttive) of the INFN–CNR (Istituto Nazionale di Fisica Nucleare–Consiglio Nazionale delle Ricerche) in Catania (Italy), was applied for the characterisation of the surface paints of some archaeological fragments of Nasca pottery from the Ceremonial Centre of Cahuachi in Southern Peru. Measurements were carried out on the black, white, red, orange and grey pigments; quantitative information on the chemical composition as well as on the mineralogical phases present on the paints were obtained. Results allowed to make some considerations about the materials and the manufacturing technique used to realise such fired pigments. It should be noted that during firing the precursor minerals composing the pigments undergo a phase transformation and their identification presents some difficulties. [Copyright &y& Elsevier]