A method for determining the relative position of two points using an inertial navigation system is described. The method comprises estimating position error states and a position solution with an INS at a first position, estimating position error states and a position solution with the INS at a second position, and returning the INS to the first position. Estimates of the first and second position error states are adjusted based on correlations developed during a transition returning the INS from the second position to the first position.