Squeezing Position Updates for Enhanced Estimation of Land Vehicles Aided INS

The case of a land vehicle traveling in a straight and leveled trajectory with a position aided inertial navigation system (INS) is considered. In such a scenario, the heading angle and some of the inertial sensors error states are not observable. To circumvent this problem, we propose a method to extract attitude information from position measurements history provided by the external sensor. Simultaneously utilizing the attitude information and position updates in the navigation filter enables the estimation of the heading angle and all of the inertial sensors error states. That is, using the proposed approach the system becomes completely observable. Simulation and field experiment results are provided to show the navigation solution performance when applying the proposed approach.