On reflected rays in axisymmetric radomes

A method is derived by which rays that reflect off the interior of a radome in a specific direction are found. It is demonstrated that these rays (if they exist) depend upon the gimbal angle. It is observed that they do not exist for gimbal angles less than a "critical gimbal angle." It is demonstrated that the critical gimbal angle is a function of the fineness ratio of the radome. Results are given for several radome geometries.