TY - JOUR
T1 - Adaptive DFT-based fringe tracking and prediction at IOTA
AU - Wilson, Edward
AU - Pedretti, Ettore
AU - Bregman, Jesse
AU - Mah, Robert W.
AU - Traub, Wesley A.
PY - 2004/10/1
Y1 - 2004/10/1
N2 - An automatic fringe tracking system has been developed and implemented
at the Infrared Optical Telescope Array (IOTA). In testing during May
2002, the system successfully minimized the optical path differences
(OPDs) for all three baselines at IOTA. Based on sliding window discrete
Fourier transform (DFT) calculations that were optimized for
computational efficiency and robustness to atmospheric disturbances, the
algorithm has also been tested extensively on off-line data. Implemented
in ANSI C on the 266 MHz PowerPC processor running the VxWorks real-time
operating system, the algorithm runs in approximately 2.0 milliseconds
per scan (including all three interferograms), using the science camera
and piezo scanners to measure and correct the OPDs. Preliminary analysis
on an extension of this algorithm indicates a potential for predictive
tracking, although at present, real-time implementation of this
extension would require significantly more computational capacity.
AB - An automatic fringe tracking system has been developed and implemented
at the Infrared Optical Telescope Array (IOTA). In testing during May
2002, the system successfully minimized the optical path differences
(OPDs) for all three baselines at IOTA. Based on sliding window discrete
Fourier transform (DFT) calculations that were optimized for
computational efficiency and robustness to atmospheric disturbances, the
algorithm has also been tested extensively on off-line data. Implemented
in ANSI C on the 266 MHz PowerPC processor running the VxWorks real-time
operating system, the algorithm runs in approximately 2.0 milliseconds
per scan (including all three interferograms), using the science camera
and piezo scanners to measure and correct the OPDs. Preliminary analysis
on an extension of this algorithm indicates a potential for predictive
tracking, although at present, real-time implementation of this
extension would require significantly more computational capacity.
M3 - Article
VL - 5491
SP - 1507
JO - New Frontiers in Stellar Interferometry, Proceedings of SPIE Volume 5491. Edited by Wesley A. Traub. Bellingham, WA: The International Society for Optical Engineering, 2004., p.1507
JF - New Frontiers in Stellar Interferometry, Proceedings of SPIE Volume 5491. Edited by Wesley A. Traub. Bellingham, WA: The International Society for Optical Engineering, 2004., p.1507
ER -