A. Surface maps of flat phantoms translated vertically.
B. Surface maps of flat phantoms rotated along the y axis, i.e., front-tilt.
C. Surface maps of flat phantoms rotated along the × axis, i.e., side-tilt.
D. Measured surface heights (squares) as a function of the expected theoretical surface heights (dashed line).
E. Measured surface angles for front-tilt (squares) and side-tilt (circles) as a function of the expected theoretical angles (dashed line).