Bias-free imaging at low light levels

James Gordon; David Buscher; Hrobjartur Thorsteinsson

doi:10.1117/12.857104

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21 July 2010 Bias-free imaging at low light levels

James Gordon, David Buscher, Hrobjartur Thorsteinsson

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Proceedings Volume 7734, Optical and Infrared Interferometry II; 77344A (2010) https://doi.org/10.1117/12.857104
Event: SPIE Astronomical Telescopes + Instrumentation, 2010, San Diego, California, United States

Abstract

Measurements from long-baseline interferometry are commonly analysed in terms of the power spectrum and the bispectrum (or triple-product) of the fringe patterns, as these estimators are invariant in the presence of phase instabilities. At low light levels, photon and detector noise give rise to systematic "bias" in the power spectrum and bispectrum. This paper extends previous work on computing the expected biases and variances for these quantities by introducing a general method which can be applied to any fringe-encoding scheme where the measurement equation is linear and to measurements affected by a combination of photon noise and detector noise. We apply our method to a number of interesting practical cases, including systems with unevenly-sampled fringe patterns and in the presence of read noise.

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James Gordon, David Buscher, and Hrobjartur Thorsteinsson "Bias-free imaging at low light levels", Proc. SPIE 7734, Optical and Infrared Interferometry II, 77344A (21 July 2010); https://doi.org/10.1117/12.857104

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