Reflectance spectral imaging is an efficient way of collecting millions of reflectance spectra over an area in one image cube (2D spatial and wavelength in the 3rd dimension). Remote VIS/NIR reflectance spectral imaging can operate at large distances (tens of metres) at submm spatial resolution. The main advantage of automated remote reflectance spectral imaging for large areas survey is the rapid scanning of large surfaces at high spatial resolution and moderate spectral resolution in the VIS/NIR from one position on the ground regardless of the height of the monument/object. The moderate spectral resolution is a trade off for large area survey within a reasonable time. It can give true colour images and images through any of the spectral filters and more importantly separating areas of different material composition based on the spectral reflectance. It can give initial material identification (both original and degraded material) to be confirmed with complementary techniques such as remote Raman spectroscopy and if appropriate remote LIBS spectroscopy. The images can also reveal faded drawings, writings and preparatory sketches, as well as areas of degradation and past intervention.
architecture, art, decorative arts, mosaics, painting, sculpture, textile
ceramics, stone, metal and metallurgical By-Products, pigments, dyes
wood, paper, textiles, dyes, organic pigments
The PRISMS system is for rapid survey of large surfaces and those at inaccessible height. It consists of a CCD camera, a filter wheel with 10 interference filters of 40nm bandwidth and central wavelength at 400nm to 850nm at 50nm interval. Either a telescope or a lens is used depending on the required spatial resolution....