This paper describes the development of methods for the dynamic measurement of error distribution for positioning systems. When a user moves along a path at an unknown speed, it is no longer feasible to calculate the distance between the measured and real positions. We apply the methods which we have developed to the evaluation of the performance of an unusual ultrasonic positioning system using reflected signal paths and compare it to a conventional ultrasonic systems and to GPS. Different correction algorithms, and the mounting of antenna/sensors are also compared. Using these objective methods we are also able to compare the results with user tests subjectively reporting the effectiveness of the positioning systems.