NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
A First Order Wavefront Estimation Algorithm for P1640 CalibratorP1640 calibrator is a wavefront sensor working with the P1640 coronagraph and the Palomar 3000 actuator adaptive optics system (P3K) at the Palomar 200 inch Hale telescope. It measures the wavefront by interfering post-coronagraph light with a reference beam formed by low-pass filtering the blocked light from the coronagraph focal plane mask. The P1640 instrument has a similar architecture to the Gemini Planet Imager (GPI) and its performance is currently limited by the quasi-static speckles due to non-common path wavefront errors, which comes from the non-common path for the light to arrive at the AO wavefront sensor and the coronagraph mask. By measuring the wavefront after the coronagraph mask, the non-common path wavefront error can be estimated and corrected by feeding back the error signal to the deformable mirror (DM) of the P3K AO system. Here, we present a first order wavefront estimation algorithm and an instrument calibration scheme used in experiments done recently at Palomar observatory. We calibrate the P1640 calibrator by measuring its responses to poking DM actuators with a sparse checkerboard pattern at different amplitudes. The calibration yields a complex normalization factor for wavefront estimation and establishes the registration of the DM actuators at the pupil camera of the P1640 calibrator, necessary for wavefront correction. Improvement of imaging quality after feeding back the wavefront correction to the AO system demonstrated the efficacy of the algorithm.
Document ID
20130000024
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
External Source(s)
Authors
Zhaia, C.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Vasisht, G.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Shao, M.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Lockhart, T.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Cady, E.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Oppenheimer, B.
(American Museum of Natural History New York, NY, United States)
Burruss, R.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Roberts, J.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Beichman, C.
(California Inst. of Tech. Pasadena, CA, United States)
Brenner, D.
(American Museum of Natural History New York, NY, United States)
Crepp, J.
(California Inst. of Tech. Pasadena, CA, United States)
Dekany, R.
(California Inst. of Tech. Pasadena, CA, United States)
Hinkley, S.
(California Inst. of Tech. Pasadena, CA, United States)
Hillenbrand, L.
(California Inst. of Tech. Pasadena, CA, United States)
Parry, I.
(Institute of Astronomy Cambridge, United Kingdom)
Pueyo, L.
(Johns Hopkins Univ. Baltimore, MD, United States)
Rice, E.
(American Museum of Natural History New York, NY, United States)
Roberts, L. C. Jr.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Sivaramakrishnan, A.
(Space Telescope Science Inst. Baltimore, MD, United States)
Soummer, R.
(Johns Hopkins Univ. Baltimore, MD, United States)
Vescelus, F.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Wallace, K.
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Zimmerman, N.
(Max-Planck-Inst. fuer Astronomie Heidelberg, Germany)
Date Acquired
August 27, 2013
Publication Date
July 1, 2012
Subject Category
Astronomy
Meeting Information
Meeting: 2012 Astronomical Telescopes and Instrumentation
Location: Amsterdam
Country: Netherlands
Start Date: July 1, 2012
End Date: July 6, 2012
Distribution Limits
Public
Copyright
Other
Keywords
Wavefront sensing
estimation
high contrast imaging
coronagraph,

Available Downloads

There are no available downloads for this record.
No Preview Available