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Proceedings Paper

Uncooperative target-in-the-loop performance with backscattered speckle-field effects
Author(s): Jan E. Kansky; Daniel V. Murphy
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Paper Abstract

Systems utilizing target-in-the-loop (TIL) techniques for adaptive optics phase compensation rely on a metric sensor to perform a hill climbing algorithm that maximizes the far-field Strehl ratio. In uncooperative TIL, the metric signal is derived from the light backscattered from a target. In cases where the target is illuminated with a laser with suffciently long coherence length, the potential exists for the validity of the metric sensor to be compromised by speckle-field effects. We report experimental results from a scaled laboratory designed to evaluate TIL performance in atmospheric turbulence and thermal blooming conditions where the metric sensors are influenced by varying degrees of backscatter speckle. We compare performance of several TIL configurations and metrics for cases with static speckle, and for cases with speckle fluctuations within the frequency range that the TIL system operates. The roles of metric sensor filtering and system bandwidth are discussed.

Paper Details

Date Published: 25 September 2007
PDF: 11 pages
Proc. SPIE 6708, Atmospheric Optics: Models, Measurements, and Target-in-the-Loop Propagation, 67080F (25 September 2007); doi: 10.1117/12.737370
Show Author Affiliations
Jan E. Kansky, MIT Lincoln Lab. (United States)
Daniel V. Murphy, MIT Lincoln Lab. (United States)

Published in SPIE Proceedings Vol. 6708:
Atmospheric Optics: Models, Measurements, and Target-in-the-Loop Propagation
Stephen M. Hammel; Alexander M. J. van Eijk; Michael T. Valley; Mikhail A. Vorontsov, Editor(s)

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