In one embodiment, a method includes accessing a trajectory and comparing a first one of multiple portions of the trajectory with a second one of the portions. A greater level of confidence is associated with the first one of the portions than the second one of the portions. The method includes determining, based on the comparison, that the first and second ones of the portions approximately magnetically coincide with each other and are not approximately colocated with each other in the trajectory; comparing a first level of confidence associated with the first one of the portions with a second level of confidence associated with the second one of the portions; and, when the first level of confidence is greater than the second level of confidence, adjusting the second one of the portions to be approximately colocated with the first one of the portions in the trajectory.