Visualization Symposium, IEEE Pacific (2012)

Songdo, Korea (South)

Feb. 28, 2012 to Mar. 2, 2012

ISBN: 978-1-4673-0863-2

pp: 121-128

ABSTRACT

The Finite Time Lyapunov Exponent (FTLE) has become a widespread tool for analyzing unsteady flow behavior. For its computation, several numerical methods have been introduced, which provide trade-offs between performance and accuracy. In order to decide which methods and parameter settings are suitable for a particular application, an evaluation of the different FTLE methods is necessary. We propose a general benchmark for FTLE computation, which consists of a number of 2D time-dependent flow fields and error measures. Evaluating the accuracy of a numerically computed FTLE field requires a ground truth, which is not available for realistic flow data sets, since such fields can generally not be described in a closed form. To overcome this, we introduce approaches to create non-trivial vector fields with a closed-form formulation of the FTLE field. Using this, we introduce a set of benchmark flow data sets that resemble relevant geometric aspects of Lagrangian structures, but have an analytic solution for FTLE. Based on this ground truth, we perform a comparative evaluation of three standard FTLE concepts. We suggest error measures based on the variance of both, the fields and the extracted ridge structures.

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CITATION

T. Weinkauf, H. Theisel, C. Rossl and A. Kuhn, "A benchmark for evaluating FTLE computations,"

*Visualization Symposium, IEEE Pacific(PACIFICVIS)*, Songdo, Korea (South), 2012, pp. 121-128.

doi:10.1109/PacificVis.2012.6183582

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