An Analysis of Panel Distortion on the Hyperboloid Surface for Ritchey–Chretien Radio Telescope

Richey-Chretien telescope (RCT) is designed as a special dual-reflector system (a pair of hyperboloid reflector) to eliminate the third order of coma and spherical aberrations in the optical system. For large radio telescope the distortional surface of the primary reflector will decrease the aperture efficiency and antenna gain. Therefore, the relationship between surface distortions and the wavefront error on aperture field should be figured out to measure the deformation on the primary mirror by wavefront-measuring technique (for instance, radio holography). In this paper, we firstly demonstrate the formula of panel distortions in the normal direction on the hyperboloid surface with wavefront error on the aperture field by geometrical and mathematic analysis. It will be useful to improve the technique of antenna alignment for RCT.