Imaging quality evaluation of aerodynamically heated optical dome using ray tracing

Area of Science:

• Optical Engineering
• Aerodynamics
• Materials Science

Background:

• Aerodynamic heating significantly alters the refractive index of optical domes.
• Thermo-optical and elasto-optical effects are critical in predicting dome performance.
• Accurate simulation of optical transmission through complex refractive index distributions is challenging.

Purpose of the Study:

• To develop and validate an irregular grid model for refractive index distribution in heated optical domes.
• To simulate optical transmission and evaluate imaging quality using a novel ray-tracing program.
• To assess the accuracy of the developed ray-tracing algorithm.

Main Methods:

• Employed an irregular grid model incorporating thermo-optical and elasto-optical theories.
• Utilized a fourth-order Runge-Kutta algorithm for ray-tracing simulations.
• Evaluated imaging quality using wave aberration of the exit pupil and modulation transfer function.
• Validated the ray-tracing program against an analytic solution for a regular gradient medium.

Main Results:

• The ray-tracing program demonstrated high accuracy in simulating optical transmission through the heated dome.
• The model successfully described the refractive index distribution influenced by aerodynamic heating.
• Both wave aberration and modulation transfer function were effective in evaluating imaging quality.

Conclusions:

• The developed irregular grid model and ray-tracing program provide a reliable method for analyzing optical dome performance under aerodynamic heating.
• The simulation accurately predicts the impact of refractive index changes on imaging quality.
• The validated program is suitable for designing and optimizing optical systems exposed to high-speed flight conditions.