Inverse Solution Error Analysis and Correction of Beam Steering System Based on Risley Prisms

The pointing accuracy of the Risley prisms beam-steering system mainly depends on the accuracy of the solution method and the impact of the error on the solution. To improve pointing accuracy, the impact of systematic errors on the inverse solution precision is investigated and a correction method is proposed. First, a more accurate error model for Risley prisms is established, and the errors are obtained by the parameter identification method, which corrects the forward solution error. Second, we explain the reason for the error generated by the inverse solution and analyze the variation of the inverse solution error magnitude with the beam deflection angle. A correction method based on pointing-field transformation is proposed. Finally, simulations and experiments are performed to verify the feasibility of the method. Experimental results show that when the beam deflection angle is equal to 0.1 degrees, the maximum and RMS values of the pointing error are reduced by 94.08% and 95.18%, respectively.