Determination of the dihedral angle errors of a corner cube from its Twyman-Green interferogram

A technique is devised for calculating the magnitudes of the dihedral angle errors of a corner cube from a single Twyman-Green interferogram. Experimental examples are given in which the dihedral angles of two corner cubes are determined to within 2 arc sec by this procedure. These values are also shown to be in good agreement with independent goniometer measurements.