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On-Line Fringe Tracking and Prediction at IOTAThe Infrared/Optical Telescope Array (IOTA) is a multi-aperture Michelson interferometer located on Mt. Hopkins near Tucson, Arizona. To enable viewing of fainter targets, an on-line fringe tracking system is presently under development at NASA Ames Research Center. The system has been developed off-line using actual data from IOTA, and is presently undergoing on-line implementation at IOTA. The system has two parts: (1) a fringe tracking system that identifies the center of a fringe packet by fitting a parametric model to the data; and (2) a fringe packet motion prediction system that uses characteristics of past fringe packets to predict fringe packet motion. Combined, this information will be used to optimize on-line the scanning trajectory, resulting in improved visibility of faint targets. Fringe packet identification is highly accurate and robust (99% of the 4000 fringe packets were identified correctly, the remaining 1% were either out of the scan range or too noisy to be seen) and is performed in 30-90 milliseconds on a Pentium II-based computer. Fringe packet prediction, currently performed using an adaptive linear predictor, delivers a 10% improvement over the baseline of predicting no motion.
Document ID
Document Type
Preprint (Draft being sent to journal)
Wilson, Edward
(NASA Ames Research Center Moffett Field, CA United States)
Mah, Robert
(NASA Ames Research Center Moffett Field, CA United States)
Lau, Sonie
Date Acquired
August 20, 2013
Publication Date
January 1, 1999
Subject Category
Funding Number(s)
Distribution Limits
Work of the US Gov. Public Use Permitted.

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