This contribution aims to offer an overview on the most interesting activities fulfilled by Members of the COST (European Cooperation in Science and Technology) Action TU1208 "Civil Engineering Applications of Ground-Penetrating Radar," concerning the use of ground-penetrating radar (GPR) and complementary non-destructive testing (NDT) techniques in archaeology and for cultural-heritage diagnostics. In most cases, archaeology exploits the great potential offered by the GPR technique in limited areas and without complementing it with other NDT approaches, whereas the combined application of multiple high resolution prospection methods at the scale of landscapes and their integrated interpretation are still uncommon. Therefore, this contribution starts with a mention to two large-scale GPR inspections, where extraordinary results were obtained. The paper continues with a review of a selection of cutting-edge case studies where GPR, eventually combined with other NDT approaches, was used to study archaeological sites and other structures of high historical value realised in different ages, ranging from the 13th century BC to the modernist period and including tombs, monuments, cathedrals, buildings, bridges and statues.

We present an algorithm for reconstructing the inner geometry of polygonal models with one or more openings (e.g. vessels). Known inner surface parts act as constraints to be fulfilled as part of the resulting solution. The calculation is done in an iterative fashion in order to minimize the difference between expected and achieved object volume. The output is a closed manifold polygonal mesh suitable for calculating properties like its volumetric capacity or for manufacturing (e.g. 3D printing). The algorithm has been applied to 111 antique vessels to allow a comparative study of their filling volumes.

Small cultural heritage institutions are facing growing problem of the rising amount of unprocessed bulk finds in their depositories. Primary focus of this paper was put on the analysis of the low-cost 3D scanner and on the investigation whether this device might be considered a suitable tool for archaeologists who need to accelerate their task. Secondary aim was to confirm whether all the advantages the high end 3D scanner has to offer are indispensable for the extraction of basic data from the bulk finds. Advantages and disadvantages of both 3D scanners were then analyzed and compared in order to determine which of the two groups is more suitable for the task.

This paper shows the first results of a diagnostic survey of the fresco paintings in two domus of the Region V in Pompeii, the Domus of C. Iulius Polybius and the Domus of Casti Amanti, which stand out for archaeological relevance and decorative asset. Especially, these cases of study were selected because pose special challenges for damage detection and conservation, due to the presence of large parts of not excavated soil behind walls and frescoes painting surfaces. The survey has been realized within the framework of "The Great Pompei Project" that aims to enhance the effectiveness of the actions and interventions for protecting the archaeological area of Pompeii by developing a special urgent programme of conservation, maintenance, and restoration. One of the main areas of intervention, where this survey is included, is the consolidation and restoration of decorated surfaces. The diagnostic methodology applied in this work is the active thermography by means of an IR thermal camera that acquires the frescoes painting surface emission due to a thermal load applied to the frescoes itself. The measurement has been conducted in reflection mode, i.e. with the camera and the thermal load source located at the same side of the painted wall, the only mode of operation in thick walls as the ancient ones. The survey allowed identifying the main frescoes damages like detachments or delaminations, fissures and moist areas. In this paper, the main problems related to the in-situ measurement by active thermography have been also illustrated and their influence on the diagnostic accuracy quantified. Specifically the issues of uniformity of the thermal load applied to the portion of the frescoes under measurement and the emissivity of its surface were deeply analyzed and their impact to the measurement quality identified.

Active thermography is a Non Destructive Technique (NDT) for composite materials testing, largely applied in aeronautics applications. Some previous works have also demonstrated its power for damage detection in frescoes and paintings. Active thermography is based on the measurement of the 2D thermal emission of an object surface when the object is exposed to a thermal flux. The thermal flux propagation inside the object affects its surface temperature and emissivity, which can be measured by an Infra-Red (IR) thermal camera. The presence of defects inside the object, as detachment between different layers, modify the propagation of the heat flow and consequently the surface temperature distribution, which can be used for the damage identification. Unfortunately, damage detection is often based on the subjective identification of discontinuities in the thermal maps that typically relies on the operator expertise. To make the identification objective, simplified mono-dimensional models have been used for the detachment modelling and for grounding their recognition and localization on a correlation between experimental thermograms and modelled ones. This paper proposes a new approach linking the experimental 2D measurements to a FE model of the element under test in order to update the model with the measured data and optimise its inputs, i.e. the thermo-mechanical characteristics of the object, to be able to localise a potential damage and its depth. In this work, the authors have performed a feasibility analysis of the method, have optimised the computational effort and have experimentally determined the properties of the material, which the object under test is made of, that have a strong influence on the uncertainty of the method itself. The 3D extension of the model is under evaluation and it will be included in a future work.