Systems and methods utilize an inertial navigation sub-system configured to determine a plurality of relative positions of the navigation system from a reference position based on the determined speed and/or acceleration and/or direction of the navigation system and/or changes thereto; and a position estimator sub-system configured to estimate the absolute position of the navigation system based on at least two received signals. A first track is defined based on the plurality of relative positions determined by the inertial navigation sub-system during a period of time and a second track is defined based on the plurality of estimates of the absolute position by calculating a best fit using the plurality of estimates of the absolute position, where the second track approximates a same shape as the first track.