REVIEW OF TECHNIQUES FOR DIRECTIONAL WAVE SPECTRA
Determination of the energy density of ocean surface waves as a function of both frequency and direction is of practical importance. With varying degrees of success several methods of measurement and analysis have been tried for this purpose in the past and their limitations should encourage the development of new techniques. Measurements are of two types: the direct measurements from within the wave field and remote measurements from without using light or radio waves. Direct measurements may be of array type or buoy type. In an array similar quantities are measured at several horizontally separated points. The highest directional resolution ever obtained to date for ocean waves appears to have been through the use of a radio backscatter technique. Several methods of analysis are used for estimating directional spectra from measurements. These are the direct Fourier transform, parameterized estimation, amplitude and phase detection technique, discrete wave train analysis, and data adaptive techniques. With sparse data as from an array of a few gages the parameterized estimation technique gives better results than the direct Fourier transform method. Data adaptive techniques such as the Maximum Likelihood Method and maximum Entropy Method can provide high resolution for directional spectra.
- Prepared in cooperation with California Univ., Berkeley, Contract DACW72-68-C-0016. Availability: Pub. in Proceedings of the International Symposium on Ocean Wave Measurement and Analysis, ASCE, New Orleans, La., 9-11 Sep 74, p669-688.
Woods Hole Oceanographic InstitutionWoods Hole, MA USA
Office of Naval ResearchDepartment of the Navy, 800 North Quincy Street
Arlington, VA USA 22217
Coastal Engineering Research CenterVicksburg, MI USA
University of California, BerkeleyBerkeley, CA USA 94720
- Panicker, N N
- Publication Date: 1974
- Pagination: 25 p.
- TRT Terms: Electromagnetic spectrum; Ocean waves; Spectrum analysis; Technology; Wave measurement
- Subject Areas: Design; Marine Transportation;
- Accession Number: 00084870
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: WHOI-74-78 Tech. Rpt., WHOI-Contrib-3391
- Contract Numbers: N00014-74-C-0262
- Files: TRIS
- Created Date: May 19 1975 12:00AM