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Demonstration of on sky contrast improvement using the Modified Gerchberg-Saxton algorithm at the Palomar Observatory

Burruss, Rick S. and Serabyn, Eugene and Mawet, Dimitri P. and Roberts, Jennifer E. and Hickey, Jeffrey P. and Rykoski, Kevin and Bikkannavar, Siddarayappa and Crepp, Justin R. (2010) Demonstration of on sky contrast improvement using the Modified Gerchberg-Saxton algorithm at the Palomar Observatory. In: Adaptive Optics Systems II. Proceedings of SPIE. No.7736. Society of Photo-Optical Instrumentation Engineers (SPIE) , Bellingham, WA, Art. No. 77365X. ISBN 978-0-8194-8226-6.

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We have successfully demonstrated significant improvements in the high contrast detection limit of the Well-Corrected Subaperture (WCS) using a number of steps aimed at reducing non-common path (NCP) wavefront errors, including the Autonomous Phase Retrieval Calibration (APRC) software package developed at the Jet Propulsion Laboratory (JPL) for the Palomar adaptive optics instrument (PALAO). APRC utilizes the Modified Gerchberg-Saxton (MGS) wavefront sensing algorithm, also developed at JPL. The WCS delivers such excellent correction of the atmosphere that NCP wavefront errors not sensed by PALAO but present at the coronagraphic image plane begin to factor heavily as a limit to contrast. The APRC program was implemented to reduce these NCP wavefront errors from 110 nm to 35 nm (rms) in the lab, and now these exceptional results have been extended to targets on the sky for the first time, leading to a significant suppression of speckle noise. Consequently we now report a contrast level of very nearly 1×10^(-4) at separations of 2λ/D before the data is post processed, and 1×10^(-5) after post processing. We describe here the major components of our instrument, the work done to improve the NCP wavefront errors, and the ensuing excellent on sky results, including the detection of the three exoplanets orbiting the star HR8799.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Mawet, Dimitri P.0000-0002-8895-4735
Hickey, Jeffrey P.0000-0002-6944-3964
Crepp, Justin R.0000-0003-0800-0593
Additional Information:© 2010 Society of Photo-Optical Instrumentation Engineers (SPIE). July 28, 2010. This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration, and is based on observations obtained at the Hale Telescope, Palomar Observatory, as part of a continuing collaboration between the California Institute of Technology, NASA/JPL, and Cornell University. We thank the staff of the Palomar Observatory and the Palomar Adaptive Optics team for their continued support. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not constitute or imply its endorsement by the United States Government or the Jet Propulsion Laboratory, California Institute of Technology.
Funding AgencyGrant Number
Cornell UniversityUNSPECIFIED
Subject Keywords:phase retrieval, mgs, high contrast coronagraphy, wavefront sensing, adaptive optics, HR8799
Series Name:Proceedings of SPIE
Issue or Number:7736
Record Number:CaltechAUTHORS:20150526-122147958
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Official Citation:Rick S. Burruss ; Eugene Serabyn ; Dimitri P. Mawet ; Jennifer E. Roberts ; Jeffrey P. Hickey ; Kevin Rykoski ; Siddarayappa Bikkannavar and Justin R. Crepp "Demonstration of on sky contrast improvement using the modified Gerchberg-Saxton algorithm at the Palomar Observatory", Proc. SPIE 7736, Adaptive Optics Systems II, 77365X (July 28, 2010); doi:10.1117/12.857544;
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:57809
Deposited By: Ruth Sustaita
Deposited On:26 May 2015 20:38
Last Modified:09 Mar 2020 13:18

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