A monochromatic continuous millimeter-wave imaging system coupled with an infrared temperature sensor has been used to investigate artistic objects such as painting artworks or antiquities preserved at the museum of Aquitaine. Especially, 2D and 3D analyses have been performed in order to reveal the internal structure of a nearly 3500-year-old sealed Egyptian jar. 1. Introduction and Background In the field of art conservation, curators and scientists are forever interested in the material composition and substructure identification for protecting our cultural heritage. This scientific analysis is essential to reveal the history of the object and discover how the artwork has been restored in past centuries. Beyond this, for the restorers, the scientific analysis of the sample composition provides information about the artist’s technique and allows an accurate material selection for future restoration. Various physical methods of diagnosis are frequently used for the purpose of material identification and investigating artists’ working methods. Fourier-transform infrared spectroscopy, Raman microscopy [1, 2], and X-ray radiography [3] are some of the commonly used methods for the analysis of artworks. To obtain detailed information about the sample, multiple spectroscopic imaging techniques are generally utilized from X-rays, ultraviolet to infrared [4, 5]. This multispectral imaging method allows us to examine the work of interest under different ranges of electromagnetic wavelengths [6, 7]. Normally all above-mentioned techniques have their own advantages and limitations compared to each others. The suitability of each method can depend on the composition, dimension, condition, and nature of the artifacts under test. Considering the shortcomings of various methods, terahertz (THz) radiation has emerged as a possible powerful candidate in the field of art conservation for the nondestructive and noninvasive investigation of various art related materials. In art painting, THz radiation can be used to analyze the materials slightly below the layers of the paint, such as preparation layers. It also has the potential for providing depth information from the paint layers. Particularly evident is the scope of the THz technique for the investigation of wall paintings where X-ray radiography cannot be easily applied. THz radiation can provide additional details and complementary spectroscopic data related to each material for a better diagnosis and understanding of an artwork. In cultural heritage science, two main aspects of THz technology can be profitably
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