Study on tightly-coupled GPS/SINS integrated navigation system by using software GPS receiver

When designing the Kalman filter of integrated navigation system, the point of pinnacle importance focuses on the systemic state equation and measurement equation. Aiming at the relativity and poor observability among measurement information in loosely coupled integrated navigation system, the tightly coupled integrated navigation system is constructed with the information fusion technology based on Kalman filter. In this mode, pseudo-range and pseudo-range rate are used as measurement information for their better observability and independence, to improve the accuracy of Kalman filter. The experiments are carried out based on semi-physical, using the actual datum which are received by Global Position System (GPS) software receiver. The results show clearly that when the accuracy of inertial components declines, the tightly coupled integration can provide higher position accuracy than the loosely coupled integration.