A Turning Direction Recognition Method Based on Exterior Measured Data for Spacecraft's Reentry

Sometimes, only the exterior measured data of the spacecraft are available during the reentry. However, the telemetry data, which are vital to the real-time turning recognition, cannot always be obtained effectively. To overcome these difficulties brought by the absent telemetry data, the major force of the spacecraft during the reentry were analyzed in order to propose some non-dynamic models, which is the foundation of the subsequent unscented Kalman filter (UKF) calculation. A turning recognition method at single point was described, which employed the orbit normal direction weights of the fore-and-aft velocity or velocity increment. Besides, a scroll statistical calculation method with multiple points is also proposed to reduce the misjudgment opportunities. The experiment results show the feasibility and validity of the proposed method which are manifested by the reentry flight trajectory calculation and the turning direction estimation.