Application of unscented R-T-S smoothing based on novel mathematical model in SINS/GPS integrated system post processing

The integrated system of Strapdown Inertial Navigation System (SINS) and Global Positioning System (GPS) has become widely-applied equipment in airborne remote sensing for getting the motion information. For the SINS/GPS integration used estimation theory, the mathematical model plays an important role in the optimal estimation of state. In this paper, the main factors that affect the precision of SINS/GPS integrated estimation in IMU calibration errors are considered and a novel nonlinear mathematical model is proposed. An unscented Rauch-Tung-Striebel smoother (URTSS) is implemented based on this model, and Monto Carlo simulation and flight test with a loaded SINS/GPS integrated system are conducted to verify the performance of this model. The comparison results indicate that the proposed nonlinear model can effectively improve the attitude estimate precision.