FUNDAMENTAL LIMITATIONS OF HIGH CONTRAST IMAGING SET BY SMALL SAMPLE STATISTICS
Top Cited Papers
- 21 August 2014
- journal article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 792 (2), 97
- https://doi.org/10.1088/0004-637x/792/2/97
Abstract
In this paper, we review the impact of small sample statistics on detection thresholds and corresponding confidence levels (CLs) in high-contrast imaging at small angles. When looking close to the star, the number of resolution elements decreases rapidly toward small angles. This reduction of the number of degrees of freedom dramatically affects CLs and false alarm probabilities. Naively using the same ideal hypothesis and methods as for larger separations, which are well understood and commonly assume Gaussian noise, can yield up to one order of magnitude error in contrast estimations at fixed CL. The statistical penalty exponentially increases toward very small inner working angles. Even at 5-10 resolution elements from the star, false alarm probabilities can be significantly higher than expected. Here we present a rigorous statistical analysis that ensures robustness of the CL, but also imposes a substantial limitation on corresponding achievable detection limits (thus contrast) at small angles. This unavoidable fundamental statistical effect has a significant impact on current coronagraphic and future high-contrast imagers. Finally, the paper concludes with practical recommendations to account for small number statistics when computing the sensitivity to companions at small angles and when exploiting the results of direct imaging planet surveys.This publication has 48 references indexed in Scilit:
- Searching for companions down to 2 AU fromβPictoris using theL′-band AGPM coronagraph on VLT/NACOAstronomy & Astrophysics, 2013
- Morphology of the very inclined debris disk around HD 32297Astronomy & Astrophysics, 2012
- Application of the Hotelling and ideal observers to detection and localization of exoplanetsJournal of the Optical Society of America A, 2007
- Broadband wavefront correction algorithm for high-contrast imaging systemsPublished by SPIE-Intl Soc Optical Eng ,2007
- High‐Contrast Imaging from Space: Speckle Nulling in a Low‐Aberration RegimeThe Astrophysical Journal, 2006
- Speckle Statistics in Adaptively Corrected ImagesThe Astrophysical Journal, 2006
- Single‐Visit Photometric and Obscurational CompletenessThe Astrophysical Journal, 2005
- The Usefulness and Limits of Coronagraphy in the Presence of Pinned SpecklesThe Astrophysical Journal, 2004
- Anomalous intensity of pinned speckles at high adaptive correctionOptics Letters, 2004
- Phase-induced amplitude apodization of telescope pupils for extrasolar terrestrial planet imagingAstronomy & Astrophysics, 2003