1. A laser tracker system for measuring six degrees of freedom, the system comprising: a tracking unit comprising: a payload assembly rotatable around at least one axis, the payload assembly comprising: a main optics assembly structured to emit a first laser beam; and a pattern projector assembly structured to emit a second laser beam shaped into a two-dimensional pattern; and a target comprising: a retroreflector; and a position sensor assembly provided proximate to the retroreflector; wherein a center of symmetry of the retroreflector is provided on a different plane than a plane of the position sensor assembly.