A mobile transmitter transmits a transmission signal from a vehicle to beacons. An estimator determines elapsed times for corresponding propagation paths between the vehicle and the beacons. Each propagation path includes at least one of a first propagation duration of a transmission signal and a second propagation duration of a return signal. A compensator compensates for noise or measurement error associated with a corresponding propagation path by invoking a linear fit scheme. The linear fit scheme applies a generally linear fit over fixed intervals of noisy measurements such that the noisy position measurements generally conform to a linear portion of a path plan of a vehicle. A data processor estimates a position of a vehicle at a confluence or intersection of the position curves or temporal curves based on elapsed times for the propagation paths.