Meadows, G. A., Shuchman, R. A., and Lyden, J. D. 1982. "Analysis 

 of Remotely Sensed Long-Period Wave Motions," Journal of Geophys- 

 ical Research, Vol 87, No. C8, pp 5731-57^0. 



Infragravity waves with periods between 15 and 200 sec were measured 

 with synthetic aperture radar (SAR). Data obtained in the nearshore region of 

 Lake Michigan indicated that the infragravity motions were a forced response 

 from interactions of wind generated incident waves. The results compared 

 favorably with an in situ wave gage. This paper demonstrated that remote 

 sensing with SAR was capable of measuring small-amplitude, low-frequency waves 

 (surf beats). However, the data did not provide actual wave height informa- 

 tion, and the exact transfer function for SAR returns from wave heights was 

 not known. 



Oltman-Shay, J., and Guza, R. T. 1987. "Infragravity Edge Wave 

 Observations on Two California Beaches," Journal of Physical 

 Oceanography , Vol 17, pp 644-663. 



Surf-zone wave velocity data were obtained from longshore arrays of 

 biaxial electromagnetic current meters for two different California beaches. 

 Wave number-frequency spectra of the infragravity wave field were computed 

 from 15 days of data. Resolution of the f-k spectra was increased by employ- 

 ing Maximum Likelihood Estimator (MLE). Low-mode (n < 2) edge waves were 

 found, on the average, to constitute 69 percent of the longshore current vari- 

 ance, 17 percent of the cross-shore current and shoreline swash variance. The 

 cross-shore velocity spectra were believed to also contain unresolvable high- 

 mode edge and leaky waves. 



The paper contains a concise and descriptive introduction on the histor- 

 ical development of infragravity wave motion theory and observations. A sec- 

 tion was included which discussed the MLE method of obtaining high-resolution 

 wave number spectra from relatively short arrays, as well as an appendix exam- 

 ining the estimator's capabilities and reliability with synthetic test spec- 

 tra. In addition to examining the infragravity energy in the surf zone, a 

 section describes edge wave energy at the shoreline measured as runup. Also, 

 the assumption of a plane beach and the presence of mean longshore currents 

 were shown to have a small but detectable effect on the measured edge wave 

 dispersion curves. 



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