Toward a diffraction-limited square-kilometer optical telescope: digital revival of intensity interferometry

Dainis Dravins; Stephan LeBohec

doi:10.1117/12.801260

22 April 2008 Toward a diffraction-limited square-kilometer optical telescope: digital revival of intensity interferometry

Dainis Dravins, Stephan LeBohec

Author Affiliations +

Proceedings Volume 6986, Extremely Large Telescopes: Which Wavelengths? Retirement Symposium for Arne Ardeberg; 698609 (2008) https://doi.org/10.1117/12.801260
Event: Extremely Large Telescopes: Which Wavelengths? Retirement Symposium for Arne Ardeberg, 2007, Lund, Sweden

Abstract

Much of the progress in astronomy follows imaging with improved resolution. In observing stars, current capabilities are only marginal in beginning to image the disks of a few, although many stars will appear as surface objects for baselines of hundreds of meters. Since atmospheric turbulence makes ground-based phase interferometry challenging for such long baselines, kilometric space telescope clusters have been proposed for imaging stellar surface details. The realization of such projects remains uncertain, but comparable imaging could be realized by ground-based intensity interferometry. While insensitive to atmospheric turbulence and imperfections in telescope optics, the method requires large flux collectors, such as being set up as arrays of atmospheric Cherenkov telescopes for studying energetic gamma rays. High-speed detectors and digital signal handling enable very many baselines to be synthesized between pairs of telescopes, while stars may be tracked across the sky by electronic time delays. First observations with digitally combined optical instruments have now been made with pairs of 12-meter telescopes of the VERITAS array in Arizona. Observing at short wavelengths adds no problems, and similar techniques on an extremely large telescope could achieve diffraction-limited imaging down to the atmospheric cutoff, achieving a spatial resolution significantly superior by that feasible by adaptive optics operating in the red or near-infrared.

Citation Download Citation

Dainis Dravins and Stephan LeBohec "Toward a diffraction-limited square-kilometer optical telescope: digital revival of intensity interferometry", Proc. SPIE 6986, Extremely Large Telescopes: Which Wavelengths? Retirement Symposium for Arne Ardeberg, 698609 (22 April 2008); https://doi.org/10.1117/12.801260

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