Lagrangian particle tracking
Lagrangian particle tracking (LPT) is a method used in fluid mechanics to analyze the motion of particles when subjected to a flow field. It provides a Lagrangian perspective, in which the flow is described by tracking fluid parcels or tracers over time, rather than observing changes at fixed locations as in the Eulerian frame.
Source: Wikipedia — Lagrangian particle tracking (CC BY-SA 4.0)