FTLE Ridge Lines for Long Integration Times

We present an approach to the extraction of FTLE ridges for 2D unsteady vector fields under long integration times. This is a hard problem because such FTLE ridges tend to be sharp and close to each other. The main feature of our approach is that it does not only use an FTLE sampling at the desired final integration time but incorporates samples from prior integration times as well. With this additional information, the new method produces more and finer ridge lines than previous approaches. Based on this output, we can consider FTLE ridge statistics. We test the approach on synthetic benchmarks and real-world data sets.