Coronagraphic Low Order Wave Front Sensor : post-processing sensitivity enhancer for high performance coronagraphs

Details Coronagraphic Low Order Wave Front Sensor : post-processing sensitivity enhancer for high performance coronagraphs Coronagraphic Low Order Wave Front Sensor : post-processing sensitivity enhancer for high performance coronagraphs

2011-12-13

arxiv.org/abs/1112.2817v1

Astronomy and Astrophysics

Astrophysics

Instrumentation and Methods for Astrophysics

10 pages, 7 figures, accepted for publication in PASP

Scientific paper

Detection and characterization of exoplanets by direct imaging requires a coronagraph designed to deliver high contrast at small angular separation. To achieve this, an accurate control of low order aberrations, such as pointing and focus errors, is essential to optimize coronagraphic rejection and avoid the possible confusion between exoplanet light and coronagraphic leaks in the science image. Simulations and laboratory prototyping have shown that a Coronagraphic Low Order Wave-Front Sensor (CLOWFS), using a single defocused image of a reflective focal plane ring, can be used to control tip-tilt to an accuracy of 10^{-3} lambda/D. This paper demonstrates that the data acquired by CLOWFS can also be used in post-processing to calibrate residual coronagraphic leaks from the science image. Using both the CLOWFS camera and the science camera in the system, we quantify the accuracy of the method and its ability to successfully remove light due to low order errors from the science image. We also report the implementation and performance of the CLOWFS on the Subaru Coronagraphic Extreme AO (SCExAO) system and its expected on-sky performance. In the laboratory, with a level of disturbance similar to what is encountered in a post Adaptive Optics beam, CLOWFS post-processing has achieved speckle calibration to 1/300 of the raw speckle level. This is about 40 times better than could be done with an idealized PSF subtraction that does not rely on CLOWFS.

Affiliated with

Also associated with

No associations

Rating

Coronagraphic Low Order Wave Front Sensor : post-processing sensitivity enhancer for high performance coronagraphs does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Coronagraphic Low Order Wave Front Sensor : post-processing sensitivity enhancer for high performance coronagraphs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coronagraphic Low Order Wave Front Sensor : post-processing sensitivity enhancer for high performance coronagraphs will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-486078