1. A calibration target for use in calibrating an imaging system, the target comprising: a plurality of markers with each marker including a plurality of localizer features and a plurality of identification features; wherein the plurality of localizer features have known relative positions on the target and are used to determine an orientation for each marker; wherein the plurality of identification features is used to determine an identification for each marker; wherein the identification for each marker of the plurality of markers is different than the identifications for all other markers of the plurality of markers; wherein the plurality of identification features for a first marker of the plurality of markers includes a first plurality of potential dot locations and a second plurality of potential dot locations; wherein the identification for the first marker is indicated by: a presence or an absence of a dot in each of the first plurality of potential dot locations so as to indicate a first pattern of dots, and a presence or an absence of a dot in each of the second plurality of potential dot locations so as to indicate a second pattern of dots which is an inverse of the first pattern of dots, wherein each potential dot location of the first plurality of potential dot locations is associated with a corresponding bit location in a binary number, wherein the first pattern of dots indicates a first binary number by the presence of a dot in each of the first plurality of potential dot locations indicating a binary one for the corresponding bit location, and by the absence of a dot in the each of the first plurality of potential dot locations indicating a binary zero for the corresponding dot location; wherein the plurality of identification features for first marker includes an additional potential dot location; and wherein a checksum for the first binary number is indicated by the presence of a dot in the additional potential dot location indicating a binary one and the absence of a dot in the additional potential dot location indicating a binary zero.