“…Identification of defects from boundary measurements plays an important role in non-destructive testing for damage assessment of mechanical specimens, which are possibly defective due to the presence of interior voids or cavities appearing during the manufacturing process, see, for instance, [33,47,55,63] for possible applications to 3D-printing and additive manufacturing. This kind of inverse problems has application also in medical imaging and in particular in elastography, a modality mapping the elastic properties and stiffness of soft tissue, [6-8, 31, 59, 60, 64] (to cite a few), and in reflection seismology [20,62], a non invasive technique used by the oil and gas industry to map petroleum deposits in the Earth's upper crust and based on seismic data from land acquisition, see for example [61]. We also mention some applications in volcanology, see for example [9,10,58] and references therein.…”