Simultaneous ultra-high contrast imaging and determination of time-dependent, non-common path aberrations in the presence of detector noise

Richard A. Frazin

doi:10.1117/12.2054356

22 July 2014 Simultaneous ultra-high contrast imaging and determination of time-dependent, non-common path aberrations in the presence of detector noise

Richard A. Frazin

Author Affiliations +

Proceedings Volume 9145, Ground-based and Airborne Telescopes V; 91453Q (2014) https://doi.org/10.1117/12.2054356
Event: SPIE Astronomical Telescopes + Instrumentation, 2014, Montréal, Quebec, Canada

Abstract

Ground-based ultra-high contrast imaging, as required for direct imaging of exoplanets and other solar systems, is limited by difficulty of separating the planetary emission from the effects of optical aberrations that are not compensated by the adaptive optics (AO) system, so-called non-common path aberrations" (NCPAs). Simultaneous (~ millisecond) exposures by the science camera and the AO system enable the use of “phase diversity" to estimate both the NCPAs and the scene via a processing procedure first described by the author (R. Frazin 2013, ApJ, 767, article id. 21).This method is fully compatible with more standard concepts used in long-exposure high-contrast imaging, such as angular differential imaging and spectral deconvolution. Long-exposure methods find time-dependent NCPAs, such as those caused by vibrations, particularly challenging. Here, an NCPA of the form of α cos(k•r-ωt + ∂) is considered. It is shown that, when sampled at millisecond time-scales, the image plane data are sensitive to arg(α), ∂ and ω, and, therefore such NCPAs can be simultaneously estimated with the scene. Simulations of observations with ms exposure times are reported. These simulations include substantial detector noise and a sinusoidal NCPA that places a speckle exactly at the location of a planet. Simulations show that the effects of detector noise can be mitigated by mixing exposures of various lengths, allowing estimation of the planet's brightness.

Citation Download Citation

Richard A. Frazin "Simultaneous ultra-high contrast imaging and determination of time-dependent, non-common path aberrations in the presence of detector noise", Proc. SPIE 9145, Ground-based and Airborne Telescopes V, 91453Q (22 July 2014); https://doi.org/10.1117/12.2054356

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