Computationally Efficient Carrier Integer Ambiguity Resolution in Multiepoch GPS/INS: A Common-Position-Shift Approach

Integer ambiguity resolution is a challenging technical issue that exists in real-time kinematic (RTK) global positioning system (GPS) navigation. Once the integer vector is resolved, centimeter-level positioning estimation accuracy can be achieved using the GPS carrier phase measurements. Recently, a real-time sliding window Bayesian estimation approach to RTK GPS and inertial navigation was proposed to provide reliable centimeter accurate-state estimation, via integer ambiguity resolution utilizing a prior along with all inertial measurement unit and GPS measurements within the time window. One challenge to implementing that approach in practice is the high computation cost. This paper proposes a novel implementation approach with significantly lower computational requirements and includes a thorough theoretical analysis. The implementation results show that the proposed method resolves an integer vector identical to that of the original method and achieves state estimation with centimeter global positioning accuracy.