Vehicle-borne non-strapdown transfer alignment method and application with poor attitude observation information

•Establish observation equation with poor attitude observation.•Give out simulation analysis and experiment verification.•Show the impact of the conventional method on alignment.•Give the accuracy comparisons between the conventional and the proposed method.•Give the quantitative results between alignment accuracy and elevation angles. For transfer alignment in elevation maneuver, the system accuracy will be decreased or divergent because of the poor attitude observation information. What is the impact on the transfer alignment with poor attitude observation information caused by non-strapdown installation is still a problem. This paper proposes a vehicle-borne non-strapdown transfer alignment method to analyze it and to reduce the impact of poor attitude observation information and establishes observation equation that match with the physical model with poor attitude observation information. The design and comparison of 37° and 80° elevation maneuver angles are carried out. Because of lacking one-degree-of-freedom attitude information, the accuracy will be lower than that of the three-degree-of-freedom attitude information. In addition, both simulation and experiments show that the proposed method can improve the alignment accuracy under the condition of poor attitude observation information. When the elevation maneuver angle is close to 90°, the proposed method has better observation performance, and the relative heading error is close to the alignment precision which is under good attitude observation information.