MACAO-VLTI piston issue: achieving the interferometry requirements

Details MACAO-VLTI piston issue: achieving the interferometry requirements MACAO-VLTI piston issue: achieving the interferometry requirements

Oct 2004

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2004spie.5490.1534i&link_type=abstract

Advancements in Adaptive Optics. Edited by Domenico B. Calia, Brent L. Ellerbroek, and Roberto Ragazzoni. Proceedings of the SPI

Physics

Optics

Scientific paper

MACAO-VLTI is a set of four adaptive optics systems dedicated to interferometry with the ESO 8 meter telescopes in Paranal, Chile. One of the most important requirements for the MACAO-VLTI is to keep the piston variations of the bimorph deformable mirror below 25 nm RMS in a time window of 48 msec. For this purpose, a piston removal algorithm has been developed, that uses a pre-calibrated set of voltages to compensate the natural piston of each influence function. This pre-calibration constitutes a critical laboratory measurement of the influence functions. Using Hadamard matrices, a (64 x 64) Shack-Hartman sensor and a capacitive sensor located at the center of the mirror (back-side), an accuracy better than 1% has been reached to characterize them. Various configurations were investigated to minimize the dynamical residual piston: the control matrix, the loop speed and the loop gain. Particular attention was paid to the influence functions non-linearities. An original indirect method was developed to measure the residual piston in real-time. We present here the methods and results obtained so far.

Affiliated with

Also associated with

No associations

Rating

MACAO-VLTI piston issue: achieving the interferometry requirements 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 MACAO-VLTI piston issue: achieving the interferometry requirements, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and MACAO-VLTI piston issue: achieving the interferometry requirements will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1810050