Workflow: Relative Velocity Variations

This section presents the three methods available to compute dv/v, assuming the Workflow: Cross-Correlation Functions steps have been completed.

Each method is self-contained. Run whichever chain(s) suit your use case.

Method 1 — MWCS (3 steps)

Moving-Window Cross-Spectrum → dt/t → dv/v aggregate (Clarke et al.[1]; Poupinet et al.[2]).

Method 2 — Stretching (2 steps)

Direct dv/v by cross-correlating stretched reference traces → dv/v aggregate (Sens-Schönfelder and Wegler[3]).

Method 3 — Wavelet Coherence Transform (2 or 3 steps)

WCT → dt/t → dv/v aggregate (Mao et al.[4]; WCT: Grinsted et al.[5]; Torrence and Compo[6]). When |wavelet.wct_compute_dtt| is True (default), the dt/t step runs inline inside the WCT step (fused, 2 steps total). Set it to False to run the dt/t step separately (3 steps total).