Before revision: In physics, the wavefront of a time-varying wave field is the set (locus) of all points having the same phase .Essential Principles of Physics, P. M. Whelan, M. J. Hodgeson, 2nd Edition, 1978, John Murray, The term is generally meaningful only for fields that, at each point, vary sinusoidally in time with a single temporal frequency (otherwise the phase is not well defined).
After revision: In physics, the wavefront of a time-varying wave field is the set (locus) of all po .Essential Principles of Physics, P. M. Whelan, M. J. Hodgeson, 2nd Edition, 1978, John Murray, The term is generally meaningful only for fields that, at each point, vary sinusoidally in time with a single temporal frequency (otherwise the phase is not well defined).