Balltracking: an highly efficient method for tracking flow fields

Potts, H.E., Barrett, R.K. and Diver, D.A. (2004) Balltracking: an highly efficient method for tracking flow fields. Astronomy and Astrophysics, 424(1), pp. 253-262. (doi: 10.1051/0004-6361:20035891)




We present a method for tracking solar photospheric flows that is highly efficient, and demonstrate it using high resolution MDI continuum images. The method involves making a surface from the photospheric granulation data, and allowing many small floating tracers or balls to be moved around by the evolving granulation pattern. The results are tested against synthesised granulation with known flow fields and compared to the results produced by Local Correlation tracking (LCT). The results from this new method have similar accuracy to those produced by LCT. We also investigate the maximum spatial and temporal resolution of the velocity field that it is possible to extract, based on the statistical properties of the granulation data. We conclude that both methods produce results that are close to the maximum resolution possible from granulation data. The code runs very significantly faster than our similarly optimised LCT code, making real time applications on large data sets possible. The tracking method is not limited to photospheric flows, and will also work on any velocity field where there are visible moving features of known scale length.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Barrett, Mr Richard and Potts, Hugh and Diver, Professor Declan
Authors: Potts, H.E., Barrett, R.K., and Diver, D.A.
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:Astronomy and Astrophysics
Publisher:EDP Sciences
ISSN (Online):1432-0746
Copyright Holders:Copyright © 2004 EDP Sciences
First Published:First published in Astronomy and Astrophysics 424(1):253-262
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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