Optical Coherence Tomography for Inspection of Aircraft Canopy Coatings

An instrument is proposed for detecting damage to coatings on aircraft canopies using a hand-held probe that can detect anomalies in either the protective coatings, structural plies, interlayers, or functional coatings such as shielding or electrostatic discharge (ESD) control layers in a laminated canopy. The instrument will utilize optical coherence tomography (OCT) to produce a three-dimensional (3D) snapshot consisting of a small area through the depth of the canopy within a few microseconds. The resulting 3D image will be analyzed to reveal physical damage to the canopy material. Image processing methods will be developed for characterizing the physical damage in terms of the sizes and shapes of anomalies, which can then be correlated to the functional properties of the coatings, for example shielding or ESD, in future efforts. By continuously acquiring data while manually scanning the probe, an entire canopy, either the inside or outside surface, can be scanned within a reasonable time. The proposed effort will demonstrate the feasibility of the method on simulated canopy material samples.