R.J. Sobey, S.A. Hughes r Coastal Engineering 36 (1999) 1736
19
Fig. 2. Measured PUV traces.
notable in trace Zb. where the sampling interval is much shorter. The P traces are
consistently smooth. In addition, time is measured independently by each sensor, and
systematic timing discrepancies are possible. This is not evident at the scale of these
plots, but becomes a potential concern at the time scale of the local analysis that is
subsequently outlined.
Analysis of simultaneous traces such as Fig. 2 has routinely adopted linear wave
theory in the interpretation of the local kinematics and in the estimation of the water
surface time history. This prior assumption of linearity has the potential for significant
misinterpretation of the actual local kinematics. Nonlinear influences may be filtered and
distorted by the record interpretation. In addition, most linear analyses assume stationary