SPIE Proceedings [SPIE Sixth International Symposium on Instrumentation and Control Technology: Sensors, Automatic Measurement, Control, and Computer Simulation - Beijing, China (Friday 13 October 2006)] Sixth International Symposium on Instrumentation and Control Technology: Sensors, Automatic Measurement, Control, and Computer Simulation - Research of interfacial-refraction-index-thickness approach for simulating large-scale aero-optical distortions