Systems and methods for estimating the distance between a start point and a true endpoint in which at least two functions of differing resolutions are used. The method includes measuring a coarse distance between the start point and an intermediate point using the lower resolution function, the intermediate point comprising a point which is substantially within one unit of the higher resolution function away from the true endpoint. Next, a vernier distance is measured from the intermediate point to a vernier endpoint using the higher resolution function, the vernier endpoint being within a narrow, vernier error window of the true endpoint. Subsequently, the coarse and vernier distances are summed to obtain the estimated distance.