A survey of the effects of reflector surface distortions on sidelobe levels

A survey of the literature relating to the effects of reflector surface distortions is presented, with particular attention to the Zernike-mode method of describing distortions and calculating the resultant radiation patterns. The errors are classified on the basis of whether they are random or systematic, since that is what determines the method of treatment. Systematic errors are further classified as periodic or nonperiodic. The results of studies into sidelobes generated by periodic surface distortions call into question the suitability of the current method of sidelobe envelope specification.<<ETX>>