Intercalibration of hyperspectral and multispectral systems for Laser Induced Fluorescence imaging

Laser Induced Fluorescence (LIF) is a well-recognized spectroscopic technique for non-destructive surface chemical analysis. It is particularly suitable for in situ analysis on delicate targets as artworks, because it does not need any sample preparation nor contact, working remotely also where only optical access is available. Hyperspectral systems have the advantage to provide whole spectra of the analysed point, and thanks to motorized optics can produce fluorescence images and map of surfaces. Since the early 2000s ENEA has developed hyperspectral LIF scanning systems. To shorten significantly analysis time, overall on very large CH surfaces as building facades, ENEA DIM Laboratory has developed an imaging multispectral LIF system. Here we present intercalibration, data analysis and software to automatically correct such imaging data and take into account filter’s bandpass and optical efficiencies with respect to systems based on the use of spectrometers, avoiding lack of selectivity and accuracy due to the absence of whole spectra.