New method of measuring the shape of precise antenna reflectors

Abstract

The shape of the paraboloidal reflector surface is determined by making a large number of measurements of the reflector curvature along several radii of the surface. These measures of curvature are then integrated twice to give the reflector profile along each radius; the results from several radii then allow the reflector surface shape to be mapped in three dimensions. The curvature measurements are made by a three‐wheeled cart with a depth sensor resting on the surface at the midpoint of the wheels. Tests of the method on an 11 m diam antenna show an average repeatability of 0.037 mm in the measurement of the shape of the parabolic reflector.