The solution represents a significant paradigm shift in target simulation. The optical scene is created by a stationary projector and then manipulated by two mirrors to cause it to appear as if coming from various angles to the UUT. The simulation computer uses the scene incident angle as input and generates the control angles for the two mirrors.
Although each mirror is manipulated by a small, two-axis positioning table, this approach is substantially less expensive than a traditional two-axis scene positioner because it maintains the target dynamics using lower cost hardware with significantly reduced power requirements. Additionally, this setup has a substantially smaller footprint than the conventional one.
Mapping the scene incident angle on the UUT to specific mirror control angles would normally require solving a system of nonlinear equations in real-time. No closed-form solutions exist for these equations and solving them through numerical algorithms would violate the real-time requirement, whereas using look-up tables, as suggested by the customer, would have an extremely large memory footprint. However, Ideal Aerosmith provided a solution that exceeded all expectations on positioning accuracy, memory footprint, and computational burden: approximation through multivariate polynomials.
A similar polynomial approximation was also provided for the in-plane scene rotation compensation, leading to an overall optimal solution.