Four-channel LIDAR relative navigation system for rocket first stage recovery at sea

Abstract In view of the shortcomings of “GPS + INS + two-way data link” navigation solution for rocket first stage recovery using vertical landing droneship, a four-channel light detection and ranging (LIDAR) relative navigation system (FCLRNS) is proposed in this paper. The system is based on the physical phenomenon that the laser reflectivity of the ship deck in the near-infrared band is four orders of magnitude higher than that of the sea surface. The FCLRNS laser detection model is established and its navigation solution which provides estimates of the trajectory inclination angle, the altitude, the speed of the rocket first stage relative to the sea/ship surface, and the roll angle of the first stage using four-channel LIDAR ranging information is formulated. Simulation results show that the FCLRNS can reliably identify the ship surface and the sea surface and accurately obtain the above navigation parameters. In order to verify the effectiveness of FCLRNS, a relative navigation experiment is conducted in which rotorcraft and reduced scale ship on the lake are used to simulate the rocket first stage recovery at sea. The experiment results are consistent with those of the simulation. The FCLRNS navigation scheme can be further combined with other systems, for example the optical system to provide full relative position and attitude information, and thus is a useful supplement to “GPS+INS+two-way data link” navigation solution for the rocket first stage recovery.