Application of extended Kalman filter in ultra-tight GPS/INS integration based on GPS software receiver

When designing the ultra-tight GPS/INS integration, the architecture of Kalman filter is the key to its successful performance; the crux of this architecture is the measurement model. Aiming at the dependence of numbers of tracked GPS satellites and poor noise immunity in loose and tight integration modes, this paper proposes a new method of ultra-tight integration, using the Q(quadrature) signal from the GPS receiver correlator, receiver position and velocity to form the measurements of the extended Kalman filter. The experiments are carried out based on semi-physics, using the factual data solved by GPS software receiver, and the results show good performance.