Imaging quality evaluation of aerodynamically heated optical dome using ray tracing

An irregular grid model was employed to describe the refractive index distribution of an aerodynamically heated optical dome according to the theories of thermo-optical and elasto-optical effects. Optical transmission through the dome was simulated using the ray-tracing program based on a fourth-order Runge-Kutta algorithm. Two kinds of imaging quality evaluation parameters were presented, wave aberration of the exit pupil and a modulation transfer function. To validate the ray-tracing program, a ray trace through a regular gradient medium was performed. Results were compared with those obtained from the analytic solution. The program was shown to possess great accuracy by using the appropriate parameters.