Velocity interferometer system for any reflector
Velocity interferometer system for any reflector (VISAR) is a time-resolved velocity measurement system that uses laser interferometry to measure the surface velocity of solids moving at high speeds. For solids experiencing high velocity impact or explosive conditions, VISAR plots the free-surface velocity against time to show the shock wave profile of a material (See Figure).
Source: Wikipedia — Velocity interferometer system for any reflector (CC BY-SA 4.0)