Qualitative and quantitative assessment of aerospace structures by pulsed thermography

Pulsed thermography (PT) is an NDT&E technique allowing the remote examination of materials and systems, PT is particularly interesting for the inspection of aerospace structures since it can be used to perform safe inspection of large structures in a fast manner and without having to remove the components from the aircraft. Pulsed thermographic data however, is contaminated by noise of many forms. Fortunately, numerous signal processing techniques are available to perform qualitative and quantitative data analysis of data. In this paper, we present three processing techniques that have shown very promising results. We provide the theoretical background and experimental details as well as some representative results that highlight the pros and cons of each technique. As it will be pointed out, an interesting approach is the combination of existing processing techniques in order to use the most attractive features from each technique while reducing the non-desirable characteristics.