Location estimators for interferometric fringes

M. Gai*, S. Casertano, D. Carollo, M. G. Lattanzi

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    28 Citations (Scopus)
    54 Downloads (Pure)


    Future global astrometry missions have targeted the determination of positions, parallaxes, and annual proper motions to the 10 μas level. This can be achieved through the use of fringe imaging interferometers, possibly featuring wide fields of view (e.g., Fizeau configurations). The basic location information is to be extracted from the fringe pattern by proper implementation of the detection system and proper exploitation of the focal plane data. The sampling resolution requirements are a key trade-off issue between science and engineering: therefore, fringe acquisition by means of realistic detectors and the resulting accuracy in photocenter location is discussed herein. The location performance is described as a X2 minimization problem; the resulting expressions are then evaluated in analytical form and by means of a Monte Carlo simulation, whch provide good agreement. In order to achieve the limiting interferometer accuracy, 8-10 pixels per fringe period are required, whereas a sampling resolution of 4-5 pixels per period provides a 30% degradation. We evaluate the location accuracy degradation induced by progressively reduced fringe visibility and increasing noise level. The former provides a smooth performance reduction, acceptable to a wide extent; read-out noise is critical because the fringe pattern signal is recorded over many pixels, each providing a comparable contribution to the overall noise.

    Original languageEnglish
    Pages (from-to)848-862
    Number of pages15
    JournalPublications of the Astronomical Society of the Pacific
    Issue number749
    Publication statusPublished - Jul 1998

    Bibliographical note

    Copyright 1998 by University of Chicago Press. Originally published in Publications of the Astronomical Society of the Pacific.


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