Photon Doppler velocimetry
Photon Doppler velocimetry (PDV) is a one-dimensional Fourier transform analysis of a heterodyne laser interferometry, used in the shock physics community to measure velocities in dynamic experiments with high temporal precision. PDV was developed at Lawrence Livermore National Laboratory by Oliver Strand.
Source: Wikipedia — Photon Doppler velocimetry (CC BY-SA 4.0)