Determining the radial position of a first read head of a storage device includes reading servo data from a storage media platter surface using the first read head, deriving from that servo data a first positron error signal representing a first estimate of the radial position of the first read head, reading the servo data from the storage media platter surface using a different read head, deriving from that servo data a second position error signal representing an estimate of the radial position of the different read head, and combining the first estimate of the radial position of the first read head and the estimate of the radial position of the different read head to obtain a revised estimate of the radial position of the first read head. The combining could include taking account of a known positional offset between the first read head and the different read head.