This study aims the monitoring of surfaces composition in order to characterize the deterioration status of historic monuments and buildings by non-destructive methods. Hyperspectral instruments, which discriminate materials on the basis of their different patterns of wavelength-specific absorption, might be employed in the characterization of the components in exposed stone surfaces, and therefore contribute to understand their conservation state. Major advantages of a such technique include its non-destructive nature and its capability of producing large areal maps at relatively low costs. In this study, gypsum is considered as a damage symptom in facades realized in marble of ancient building. The co-presence of other minerals such as whewellite, weddellite, carbon particles, has been taken into account as well. Two hyperspectral sensors have been employed to obtain maps of gypsum distribution in the façade of Santa Maria Novella Church in Florence–Italy (XV century). Two hyperspectral devices have been employed: the portable ASD-FieldSpec FR Pro spectroradiometer and the Selex Galileo Multisensor Hyperspectral System (Hyper SIM-GA), both operating in the spectral range 350-2500 nm and having a spatial resolution of few centimetres. The signals between 1450-1550 nm and at 1750 nm have been used for identification and estimation of gypsum. Reflectance measurements have been performed by FieldSpec using the contact probe in order to create a gypsum distribution maps, to be compared with those obtained by Hyper SIM-GA sensor. Small fragments have been also studied by FT-IR, XRD and SEM-EDS analyses. The results show that the hyperspectral technique is a valid tool for detecting the gypsum content in complex matrix; however, it has to be considered that in the case of alteration areas constituted by gypsum associated to particulate (the so called “black crusts”), the whole spectrum intensity may be reduced and as a consequence, the detection of gypsum may be hindered.
Employment of hyper spectral techniques for monitoring of historical building surfaces / S. Vettori; M. Camaiti; L. Chiarantini; P. Costagliola; S. Moretti; F. Paba; E. Pecchioni. - ELETTRONICO. - (2011), pp. 30-30. (Intervento presentato al convegno 10th International Conference Art11 on non destructive investigations and microanalysis for diagnostics and conservation of cultural and environmental heritage, Florence tenutosi a Florence nel 13-15 Aprile 2011).
Employment of hyper spectral techniques for monitoring of historical building surfaces
VETTORI, SILVIA;CHIARANTINI, LAURA;COSTAGLIOLA, PILARIO;MORETTI, SANDRO;PECCHIONI, ELENA
2011
Abstract
This study aims the monitoring of surfaces composition in order to characterize the deterioration status of historic monuments and buildings by non-destructive methods. Hyperspectral instruments, which discriminate materials on the basis of their different patterns of wavelength-specific absorption, might be employed in the characterization of the components in exposed stone surfaces, and therefore contribute to understand their conservation state. Major advantages of a such technique include its non-destructive nature and its capability of producing large areal maps at relatively low costs. In this study, gypsum is considered as a damage symptom in facades realized in marble of ancient building. The co-presence of other minerals such as whewellite, weddellite, carbon particles, has been taken into account as well. Two hyperspectral sensors have been employed to obtain maps of gypsum distribution in the façade of Santa Maria Novella Church in Florence–Italy (XV century). Two hyperspectral devices have been employed: the portable ASD-FieldSpec FR Pro spectroradiometer and the Selex Galileo Multisensor Hyperspectral System (Hyper SIM-GA), both operating in the spectral range 350-2500 nm and having a spatial resolution of few centimetres. The signals between 1450-1550 nm and at 1750 nm have been used for identification and estimation of gypsum. Reflectance measurements have been performed by FieldSpec using the contact probe in order to create a gypsum distribution maps, to be compared with those obtained by Hyper SIM-GA sensor. Small fragments have been also studied by FT-IR, XRD and SEM-EDS analyses. The results show that the hyperspectral technique is a valid tool for detecting the gypsum content in complex matrix; however, it has to be considered that in the case of alteration areas constituted by gypsum associated to particulate (the so called “black crusts”), the whole spectrum intensity may be reduced and as a consequence, the detection of gypsum may be hindered.
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