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Demonstration of on Sky Contrast Improvement Using the Modified Gerchberg-Saxton Algorithm at the Palomar ObservatoryWe have successfully demonstrated significant improvements in the high contrast detection limit of the Well-Corrected Subaperture (WCS) using 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 non-common path (NCP) wavefront errors not sensed by PALAO but present at the coronagraphic image plane begin to factor heavily as a limit to contrast. We have implemented the APRC program to reduce these NCP wavefront errors from 110 nm to 35 nm (rms) in the lab, and we have extended these exceptional results 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 1x10(exp -4) at separations of 2 lambda/D before the data is post processed. 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.
Document ID
20150008497
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
External Source(s)
Authors
Burruss, Rick S.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Serabyn, Eugene
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Mawet, Dimitri P.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Roberts, Jennifer E.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Hickey, Jeffrey P.
(California Inst. of Tech. Pasadena, CA, United States)
Rykoski, Kevin
(California Inst. of Tech. Pasadena, CA, United States)
Bikkannavar, Siddarayappa
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Crepp, Justin R.
(California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
May 20, 2015
Publication Date
June 27, 2010
Subject Category
Computer Programming And Software
Instrumentation And Photography
Astronomy
Meeting Information
Meeting: SPIE Astronomical Telescopes and Instrumentation 2010
Location: San Diego, CA
Country: United States
Start Date: June 27, 2010
End Date: July 2, 2010
Sponsors: International Society for Optical Engineering
Distribution Limits
Public
Copyright
Other
Keywords
mgs
adaptive optics
wavefront sensing
HR8799
high contrast coronagraphy
phase retrieval

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