Title: Current Trends in Spectral Reflectance Imaging Techniques
Description: Preservationists utilize many techniques to evaluate sites and monuments, and continually strive for increasing levels of accuracy. Today researchers are able to virtually reconstruct objects, buildings and entire sites through the use of digital-imaging technology, and many of these same techniques are being adapted to provide non-destructive documentation and material analysis. Increasing portability and decreasing cost of digital-imaging equipment promises to yield myriad avenues for investigation and provide further opportunities for accurate documentation. In consultation with imaging specialists and Columbia University faculty, a range of imaging techniques have been selected which represent potentially viable methods for non-destructive material analysis. Techniques of particular interest involve data collection within the visible and infrared regions of the electromagnetic spectrum, including thermographic-IR imaging, multispectral imaging, and hyperspectral imaging. By examining the materials associated with historic structures (e.g. stone, metal, brick, terra cotta, concrete and wood) and imaging technologies currently available, it is the goal of this research project to create a model for determining appropriate imaging techniques necessary to decipher construction materials.

In doing so, this paper attempts to qualitatively examine the feasibility of using spectral-imaging for in-situ exterior survey and assessment of building facades, where it can be important to quickly, remotely and non-destructively distinguish among original construction, biological growth, paint, and other colored building materials.