Methods, systems, and apparatus, including medium-encoded computer program products, for 3D flight tracking of objects include a method including determining a golf ball trajectory based on observations by sensor(s), extrapolating the trajectory backward in time, calculating distance measure(s) between the extrapolated trajectory and physical locations, estimating a systemic error for observation(s), wherein the systemic error affects observed ball positions, estimating a stochastic error associated with the observation(s), wherein the stochastic error affects an angle of a trajectory determined from observed ball positions, combining the estimated systemic and stochastic errors to form error measure(s) for the distance measure(s), identifying one of the physical locations as an origin for the golf ball when the error measure(s) satisfy a criterion, and waiting for additional observations of the golf ball by the sensor(s) when the error measure(s) do not satisfy the criterion.