We present methods for detecting phase synchronization of two unidirectionally coupled, self-sustained noisy oscillators from a signal of the driven oscillator alone. One method detects soft, another hard phase locking. Both are applied to the problem of detecting phase synchronization in von Karman vortex flow meters.
@article{arxiv.nlin/0505011,
title = {Phase synchronization from noisy univariate signals},
author = {A. G. Rossberg and K. Bartholome and H. U. Voss and J. Timmer},
journal= {arXiv preprint arXiv:nlin/0505011},
year = {2007}
}