High-Speed Surface Measurement Device

Weather conditions that may affect the design of missile radomes, windows and leading edges include the presence of rain, snow/sleet in the atmosphere and sand during missile flight trajectory. The Tri-Service Agencies Weather Encounter Advisory Group led by AMRDEC is organizing tests to study the detailed fracture mechanics of brittle ceramics radome material in free flight. In this proposed work we will develop a dynamic holographic interferometry technique to measure dynamic surface deformations of a fast moving missile. Specifically, we will analyze and evaluate different optical methods, and design experimental holographic interferometry set-ups for measuring deformations of a missile radome moving in a rain field or in a sand cloud. We will be using combined approaches of digital holography and analog holography. Initially, we plan to use CW analog holographic schemes with a controlled shutter that will allow performing analog holographic interferometry using thermoplastic holocamera or photorefractive materials. Also, parallel methods using digital holography and digital holographic interferometry will be used. Finally, we will develop numerical models that analyze analog holographic interference patterns and digital holographic interferometry results to infer changes in surface map of the radome due to deformations.