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20 October 2004 A novel method of reconstruction for weak-phase optical interferometry
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Current optical interferometers are affected by unknown turbulent phases on each telescope. The complex Fourier samples measured by the instrument are thus multiplied by unknown phasers corresponding to the turbulent differential pistons between each couple of telescopes. So, the only unaffected phase information is the closure phase of each coherent sub-array. Following the radio-interferometry paradigm, we account for the lack of phase information by introducing system aberration parameters, which are structurally analogous to the turbulent differential pistons. Then, we reconstruct the object by minimizing an original criterion in the object and these aberrations. We have recently designed a metric such that the minimization problem is convex for given aberrations while modeling accurately the noise statistics. The joint criterion is obtained by taking into account the aberrations in this metric. Here, we show how to compute the global minimum of the joint criterion for the aberration step, in spite of the fact that the latter is dramatically non unimodal. This is achieved by exploiting the separable structure of the aberration estimation problem for a known object. Then, we minimize the by optimizing alternatively the object for the current aberrations and the aberrations for the current object. We are currently testing our technique on experimental data.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Serge C. Meimon, Laurent M. Mugnier, and Guy Le Besnerais "A novel method of reconstruction for weak-phase optical interferometry", Proc. SPIE 5491, New Frontiers in Stellar Interferometry, (20 October 2004);

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