Standard particle image velocimetry (PIV) systems record image pairs separated by a short interval, but successive pairs are often far apart in time. The resulting data are not time-resolved, which makes it difficult to extract temporal dynamics with conventional modal-analysis methods such as dynamic mode decomposition (DMD).
Gap-based dynamic mode decomposition (gDMD) addresses this by extracting DMD modes from standard, non-time-resolved PIV data. The approach is described in a paper accepted in Physical Review Fluids (September 2026): doi.org/10.1103/4g2g-7mh7.
