DETERMINATION OF DIRECTIONAL SPECTRA OF OCEAN WAVES FROM GAGE ARRAYS

This study is concerned with the development of a comprehensive and general procedure for determining directional spectra (i.e., the distribution of wave energy with respect to frequency and direction) and its testing and application. Two methods for analyzing data from gage arrays to obtain directional spectra are developed and presented. These are the "locked phase" mode of analysis to analyze deterministic wave data and the "Independent Phase" mode of analysis to analyze random wave data. For each frequency, the directional spectrum is represented as a truncated Fourier series in terms of directions. In the general analysis, the wave data are assumed to be measurements of any wave parameter and transfer functions derived from the linear theory of waves (and also the linearization of wave forces) are incorporated in the analysis. Additionally, a procedure "Half Circle Analysis", is derived and presented for use when waves come from directions within a half circle. Computational schemes utilizing the developed analytical procedures are implemented in computer programs written in Fortran IV. Resolving power of different wave-gage arrays are compared. Directional spectra from data taken on a 5-gage CERC array off Point Mugu, California, are obtained using the theory and computer program developed, and are examined. Among other conclusions based on this study, the authors report that, for the determination of directional spectra, a general scheme of computation is possible if wave data are taken on an array of gages and directional spectral density for each frequency is represented as a truncated Fourier series; and that the sharpness of the directional resolution can be improved if permissible restrictions on the range of the wave directions are incorporated into the analysis by modifying the Fourier series representation.

• Supplemental Notes:
  • This study was partially supported by Contract Number DACW 72-68-C-0016 with the Coastal Engineering Research Center, U.S. Army Corps of Engineers. This dissertation submitted in partial fulfillment of PhD requirements.
• Corporate Authors:

  University of California, Berkeley

  Hydraulic Engineering Laboratory
  Berkeley, CA  United States 
• Authors:
  • Paniker, N N
• Publication Date: 1971-8

Media Info

• Features: References;
• Pagination: 315 p.

Subject/Index Terms

• TRT Terms: Electromagnetic spectrum; Energy; Ocean waves; Technology; Wave measurement
• Old TRIS Terms: Energy spectra; Wave gages
• Subject Areas: Energy; Marine Transportation; Terminals and Facilities;

Filing Info

• Accession Number: 00051019
• Record Type: Publication
• Source Agency: National Maritime Research Center, Galveston
• Report/Paper Numbers: HEL 1-1 Tech Rpt
• Files: TRIS
• Created Date: Feb 20 1974 12:00AM