Measuring optical distortion in aircraft transparencies: a fully automated system for quantitative evaluation

We describe a complete system for quantitatively measuring the optical distortion in aircraft windshields and automatically classifying that distortion as acceptable or not. The system comprises two parts: The first uses digital imaging of a known grid pattern through the windshield of interest to create a distortion map of that windshield; the second uses the distortion maps created for 100 windshields (some acceptable and some not) and automatically learns a decision-tree-based classifier. We show results that highlight the robustness of this system, including a demonstration that the distortion map for a windshield is consistently measured over 3 years, and cross-validation study shows that we can effectively classify windshields based on the distortion maps.