title: High-precision fringe tracking invariant to systematic model errors.
abstract: We present a new approach to processing of interferometric data, which dramatically improves operation on the smallest fraction of the fringe (approximately 1/1,000 of a wavelength and beyond). In particular, this approach, dubbed the variation-invariant subspace tracking approach (VISTA), makes it possible to operate a Michelson interferometer in a highly stable mode in which the estimation of optical path delay becomes invariant (insensitive) to a large class of systematic model errors. This previously unknown invariance property of interferometry follows from the fundamental odd-even symmetry of the channeled spectrum and its derivatives. VISTA offers a powerful algorithmic alternative for alleviating technological challenges in the design of high-precision long-baseline spaceborne interferometers.
authors.affiliation: SBI-Moldyn Inc, Cambridge, Massachusetts 02139, USA.
authors.forename: V I
authors.initials: VI
authors.lastname: Karlov
authors.forename: C E
authors.initials: CE
authors.lastname: Padilla
authors.forename: K
authors.initials: K
authors.lastname: Soosaar
authors.forename: L E
authors.initials: LE
authors.lastname: Matson
authors.forename: H M
authors.initials: HM
authors.lastname: Chun
authors.forename: G V
authors.initials: GV
authors.lastname: Webb