  High-accuracy and high-efficiency finite-time Lyapunov exponent (FTLE)
calculation method has long been a research hot point, and adaptive refinement
method is a kind of method in this field. The proposed objective-adaptive
refinement (OAR) criterion can put adaptive particles at the vicinity of FTLE
ridges. The FTLE ridge is extracted not simply by the magnitude of FTLE (would
cause false negative refinement) and error (would cause false positive
refinement) but by a modified gradient climbing method. Moreover, the
refinement regions converge to some certain region because of the objectivity
of the refinement region.
