The direction vector assisted INS/spectral redshift integrated navigation system for spacecraft

A reliable and autonomous navigation system is crucial for achieving high survivability of spacecraft. As a novel autonomous navigation system, an inertial/spectral redshift (INS/SRS) integrated navigation system can correct the navigation errors of INS through redshift and direction vector information from celestial bodies. However, since SRS needs to obtain position measurements by integrating the velocity information of the spacecraft, the position error from INS/SRS diverges. Therefore, this paper investigates a direction vector-assisted INS/SRS integrated navigation system for spacecraft. It examines the relationship among the position of the spacecraft, redshift, and direction vectors from celestial bodies. Then, a direction vector-assisted SRS is proposed, which can solve the position information of spacecraft directly by using redshift and direction vector information. Finally, the direction vector-assisted SRS is combined with INS to form the direction vector-assisted INS/SRS integrated navigation system. Simulations and comprehensive analysis demonstrate that the proposed integrated navigation system has better performance than the conventional INS/SRS integrated navigation system.