title: Synthetic aperture interferometry: error analysis.
abstract: Synthetic aperture interferometry (SAI) is a novel way of testing aspherics and has a potential for in-process measurement of aspherics [Appl. Opt. 42, 701 (2003)]. A method to measure steep aspherics using the SAI technique has been previously reported [Appl. Opt. 47, 1705 (2008)]. Here we investigate the computation of surface form using the SAI technique in different configurations and discuss the computational errors. A two-pass measurement strategy is proposed to reduce the computational errors, and a detailed investigation is carried out to determine the effect of alignment errors on the measurement process.
authors.affiliation: Electro-Optical Systems Group, Sensors Development Area, Space Applications Centre, Indian Space Research Organisation, Ahmedabad 380015, Gujarat, India. amiya@sac.isro.gov.in
authors.forename: Amiya
authors.initials: A
authors.lastname: Biswas
authors.forename: Jeremy
authors.initials: J
authors.lastname: Coupland