Geometric optical image aberrations of single and double mirrors.

The advantages and disadvantages of single and double mirror systems are considered. Geometrical image aberrations of spherical and paraboloidal single mirrors are given as functions of the focal number and angle of field, and geometrical image aberrations of paraboloidal-hyperboloidal double mirror systems are given as functions of primary focal number, secondary magnification, angle of field, and mutual position tolerances. The image aberrations for present and future diameter ranges are discussed in relation to wave optical limits. Optimal sizes of uncorrected fields of view are derived for different focal numbers.