A metrology frame having a reference axis and comprising a carriage , wherein the carriage is structured to include: - a housing base ; and - at least one retroreflector holder affixed to the housing base and configured to receive thereat at least one optical retroreflector , characterized in that the housing base contains a set of fiducial structures and is dimensioned to receive and removably hold thereat an optical workpiece such that at least one of a first spatial position and a first spatial orientation of a first reference point of the optical workpiece is in a first pre-defined dimensional relationship with respect to the set of fiducial structures , the at least one retroreflector holder is configured to receive and removably hold thereat at least one optical retroreflector structure such that at least one of a second spatial position and a second spatial orientation of a second reference point of the at last one optical retroreflector structure is in a second pre-defined dimensional relationship with respect to the set of fiducial structures , the at least one optical retroreflector structure comprising a corresponding optical retroreflector of the at least one optical retroreflector (274 A), the metrology frame further comprises: - a support base dimensioned to support the carriage attached thereto such that the at least one retroreflector holder is separated from the support base by said carriage , and - at least one bearing cooperated with at least one of the carriage and the support base and configured to moveably vary a least one of a mutual position and a mutual orientation of the support base and the carriage . - a housing base ; and - at least one retroreflector holder affixed to the housing base and configured to receive thereat at least one optical retroreflector , the housing base contains a set of fiducial structures and is dimensioned to receive and removably hold thereat an optical workpiece such that at least one of a first spatial position and a first spatial orientation of a first reference point of the optical workpiece is in a first pre-defined dimensional relationship with respect to the set of fiducial structures , the at least one retroreflector holder is configured to receive and removably hold thereat at least one optical retroreflector structure such that at least one of a second spatial position and a second spatial orientation of a second reference point of the at last one optical retroreflector structure is in a second pre-defined dimensional relationship with respect to the set of fiducial structures , the at least one optical retroreflector structure comprising a corresponding optical retroreflector of the at least one optical retroreflector (274 A), the metrology frame further comprises: - a support base dimensioned to support the carriage attached thereto such that the at least one retroreflector holder is separated from the support base by said carriage , and - at least one bearing cooperated with at least one of the carriage and the support base and configured to moveably vary a least one of a mutual position and a mutual orientation of the support base and the carriage . - a support base dimensioned to support the carriage attached thereto such that the at least one retroreflector holder is separated from the support base by said carriage , and - at least one bearing cooperated with at least one of the carriage and the support base and configured to moveably vary a least one of a mutual position and a mutual orientation of the support base and the carriage . <EOS>