central Fire Island using the April 1995 shoreline data set. After extracting the shoreline
undulation signal from the shoreline position data, the next step involved processing the
shoreline undulation data through the FFT analysis routine. The power spectrum
estimates that resulted from the analysis were smoothed, and spectral peaks in the
smoothed version of the power spectrum were used to identify the dominant shoreline
undulation wavelengths. An example of the raw and smoothed power spectrum that
resulted from the FFT analysis of the April 1995 shoreline undulation data set is provided
in Fig. 6. Each of the shoreline undulation data sets were processed as described above
and comparable results were obtained. Table 2 provides a summary of the results
obtained from the spectral analysis. From Table 2 it is seen that in general only two
spectral peaks were identified from the shoreline position data sets that were interpreted
from aerial photography (only the March 1988 data set gave three spectral peaks). The
corresponding shoreline undulation wavelengths were found to range from about 1 to
1.8 km. The data sets that were obtained by GPS survey methods resulted in the
identification of not less than two and often more than three spectral peaks corresponding