December 14, 2001
Many optical guidance sensors view the outside world through a protective window of some kind. These windows are not merely an adjunct to the system but rather an integral component. Nominal properties of these windows are taken into consideration in the optical design of the overall sensor. For missile applications, there are certain flight conditions that affect these windows (through aerodynamic heating) and hence the imaging performance of the sensor. Subsequently, this change in optical performance affects the guidance of the vehicle in a dynamic sense. Presented in this lecture is a series of optical techniques for assessing the performance of these windows. This assessment is of the complete thermo-mechanical behavior as well as the bottom line impact on the image quality of the sensor that looks through the window. The entire discussion serves as a vehicle for emphasizing the role that fundamental research plays in the everyday mission of APL and its often critical role in achieving major programmatic milestones.
Dr. Donald Duncan received the B.S. (1970) from the University of Kentucky, and the M.S. (1973) and Ph.D. (1977) degrees from the Ohio State University, all in Electrical Engineering. From 1977 until 1983, he worked at Pacific-Sierra Research Corporation where he performed research on laser propagation through turbulent, aerosol-laden media. He joined the Applied Physics Laboratory in 1983 as a Senior Staff Engineer, specializing in physical optics. A member of the APL Principal Professional Staff since 1989, he is currently the Section Supervisor of the Phenomenology and Measurements section of the Electooptics Group of ADSD. Since 1987, he has taught courses in Fourier and statistical optics, laser engineering, optical techniques in non-destructive evaluation (NDE), and stochastic processes at the Homewood campus and in the Part-Time Engineering program at APL. For the academic year 1992-1993 he was the J. H. Fitzgerald Dunning Visiting Professor in the Department of Materials Science and Engineering where he conducted research on the use of laser speckle techniques in NDE. Since 1995, he has held an appointment as Associate Professor of Ophthalmology in the Department of Medicine, where he is involved in researching the epidemiology of cataract.