Interpreting Galilean Invariant Vector Field Analysis via Extended Robustness: Extended Abstract

Motivation. Understanding vector fields is integral to many scientific applications ranging from combustion to global oceanic eddy simulations. Critical points of a vector field (zeros of the field) are essential features of the data, and play an important role in describing and interpreting the flow behavior. However, vector field analysis based on critical points suffers a major drawback: the definition of critical points depends upon the chosen frame of reference. Fig. 1 highlights this limitation, where the critical points in a simulated flow (the von Kármán vortex street) are only visible when the velocity of the incoming flow is subtracted. The extraction of meaningful features in the data therefore depends on a good choice of a reference frame. Often times there exists no single frame of reference that enables simultaneous visualization of all relevant features. For example, it is not possible to find one single frame that simultaneously shows the von Kármán vortex street from Fig. 1(b), and the first vortex formed directly behind the obstacle in Fig. 1(a). To overcome such a drawback, a framework recently introduced by Bujack et al. [1] considers every point as a critical point and locally adjusts the frame of reference to enable simultaneous visualization of dominating frames that highlight features of interest. Such a framework selects a subset of critical points