Fringe fitting for coherent integrations with the NPOI

Anders M. Jorgensen; David Mozurkewich; J. Thomas Armstrong; Robert Hindsley; Thomas A. Pauls; G. Charmaine Gilbreath; Sergio Raffaele Restaino

doi:10.1117/12.552279

20 October 2004 Fringe fitting for coherent integrations with the NPOI

Anders M. Jorgensen, David Mozurkewich, J. Thomas Armstrong, Robert Hindsley, Thomas A. Pauls, G. Charmaine Gilbreath, Sergio Raffaele Restaino

Author Affiliations +

Proceedings Volume 5491, New Frontiers in Stellar Interferometry; (2004) https://doi.org/10.1117/12.552279
Event: SPIE Astronomical Telescopes + Instrumentation, 2004, Glasgow, United Kingdom

Abstract

We have developed a method for performing long coherent integrations with the Navy Prototype Optical Interferometer (NPOI), which is based on fitting a model fringe pattern to the NPOI data frames. The procedure is quite computationally intensive, but gives a better estimation of the phase than the conventional method of location the peak of the group delay power. We mention briefly some of the most important past work on coherent integration, and then describe our method. We conclude that the fitting approach produces a phase with fewer outliers than the Fourier-transform group delay approach. We show how the instrumental squared visibility varies as a function of the fringe model used, and show that it provides a better SNR than the FT method. The phase determination will always be imperfect, and thus cause a reduction in the visibility amplitude relative to the true instrumental visibility. We illustrate a method for calibrating the visibility amplitude. With long coherent integrations the phase of the visibility can be extracted. We show examples of visibility phases and how to correct them for phase variations in the instrument. Finally, we illustrate a method for measuring stellar diameters very precisely, to one part in at least several hundred.

Citation Download Citation

Anders M. Jorgensen, David Mozurkewich, J. Thomas Armstrong, Robert Hindsley, Thomas A. Pauls, G. Charmaine Gilbreath, and Sergio Raffaele Restaino "Fringe fitting for coherent integrations with the NPOI", Proc. SPIE 5491, New Frontiers in Stellar Interferometry, (20 October 2004); https://doi.org/10.1117/12.552279

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available