Radio Guidance Command Design for Target Angle Correction of Sounding Rocket S-520-RD1

This paper explores a novel approach for deriving target angle correction commands in rhumb line control, a widely-used attitude control method, in JAXA's sounding rocket S-520-RD1. To fulfill strict attitude requirements during the flight of S-520-RD1, radio guidance is implemented to rectify the target angle of the rhumb line control. We introduce a sensitivity matrix that can compute the correction command using radar tracking data, and propose a way to derive the matrix from a pre-determined nominal orbit. To account for command resolution limitations and wind-related effects, we verify the effectiveness of our proposed method through the Monte-Carlo simulations. Furthermore, we present the flight result of the S-520-RD1 using our method, which demonstrates precise attitude control.