Skip to main content
Log in

Decomposition techniques for the ocean wave identification problem

  • Contributed Papers
  • Published:
Journal of Optimization Theory and Applications Aims and scope Submit manuscript

Abstract

This paper deals with the solution of the ocean wave identification problem by means of decomposition techniques. A discrete formulation is assumed. An ocean test structure is considered, and wave elevation and velocities are assumed to be measured with a number of sensors. Within the frame of linear wave theory, a Fourier series model is chosen for the wave elevation and velocities. Then, the following problem is posed (Problem P): Find the amplitudes of the various wave components of specified frequency and direction, so that the assumed model of wave elevation and velocities provides the best fit to the measured data. Here, the term best fit is employed in the least-square sense over a given time interval.

Problem P is numerically difficult because of its large size 2MN, whereM is the number of frequencies andN is the number of directions. Therefore, both the CPU time and the memory requirements are considerable (Refs. 7–12).

In order to offset the above difficulties, decomposition techniques are employed in order to replace the solution of Problem P with the sequential solution of two groups of smaller subproblems. The first group (Problem F) involvesS subproblems, having size 2M, whereS is the number of sensors andM is the number of frequencies; theseS subproblems are least-square problems in the frequency domain. The second group (Problem D) involvesM subproblems, having size 2N, whereM is the number of frequencies andN is the number of directions; theseM subproblems are least-square problems in the direction domain.

In the resulting algorithm, called the discrete formulation decomposition algorithm (DFDA, Ref. 2), the linear equations are solved with the help of the Householder transformation in both the frequency domain and the direction domain. By contrast, in the continuous formulation decomposition algorithm (CFDA, Ref. 1), the linear equations are solved with Gaussian elimination in the frequency domain and with the help of the Householder transformation in the direction domain.

Mathematically speaking, there are three cases in which the solution of the decomposed problem and the solution of the original, undecomposed problem are identical: (a) the case where the number of sensors equals the number of directions; (b) the case where Problem P is characterized by a vanishing value of the functional being minimized; and (c) the case where the wave component periods are harmonically related to the sampling time.

Numerical experiments concerning the OTS platform and the Hondo-A platform show that the decomposed scheme is considerably superior to the undecomposed scheme; that the discrete formulation is considerably superior to the continuous formulation; and that the accuracy can be improved by proper selection of the sampling time as well as by proper choice of the number and the location of the sensors. In particular, the choice of the sensor location for the Hondo-A platform is discussed.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Subscribe and save

Springer+ Basic
$34.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or eBook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Miele, A., Wang, T., andZhao, Z. G.,Decomposition Techniques for the Ocean Wave Identification Problem, Part 1, Continuous Formulation, Rice University, Aero-Astronautics Report No. 185, 1985.

  2. Miele, A., Wang, T., andZhao, Z. G.,Decomposition Techniques for the Ocean Wave Identification Problem, Part 2, Discrete Formulation, Rice University, Aero-Astronautics Report No. 186, 1985.

  3. Miele, A., andWang, T.,Decomposition Techniques for the Ocean Wave Identification Problem, Part 3, Equivalence Proofs, Rice University, Aero-Astronautics Report No. 187, 1985.

  4. Miele, A., andWang, T.,Decomposition Techniques for the Ocean Wave Identification Problem, Part 4, Condition Number and Error Analysis, Rice University, Aero-Astronautics Report No. 188, 1985.

  5. Miele, A., Wang, T., andZhao, Z. G.,Decomposition Techniques for the Ocean Wave Identification Problem, Part 5, Numerical Results for the OTS Platform, Rice University, Aero-Astronautics Report No. 189, 1985.

  6. Miele, A., Wang, T., andZhao, Z. G.,Decomposition Techniques for the Ocean Wave Identification Problem, Part 6, Numerical Results for the Hondo-A Platform, Rice University, Aero-Astronautics Report No. 190, 1985.

  7. Miele, A., andWang, T.,Wave Parameter Identification Problem for Ocean Test Structure Data, Part 1, Continuous Formulation, Rice University, Aero-Astronautics Report No. 170, 1983.

  8. Miele, A., andWang, T.,Wave Parameter Identification Problem for Ocean Test Structure Data, Part 2, Discrete Formulation, Rice University, Aero-Astronautics Report No. 172, 1983.

  9. Miele, A., andWang, T.,Wave Parameter Identification Problem for Ocean Test Structure Data, Part 3, Numerical Results, Rice University, Aero-Astronautics Report No. 173, 1983.

  10. Miele, A., andWang, T.,Wave Parameter Identification Problem for Ocean Test Structure Data, Part 4, Theoretical Basis, Rice University, Aero-Astronautics Report No. 174, 1983.

  11. Miele, A., Wang, T., Heideman, J. C., andSharma, J. N.,Wave Parameter Identification Problem for Ocean Test Structure Data, Part 1, Continuous Formulation, Journal of Optimization Theory and Applications, Vol. 44, No. 2, pp. 269–302, 1984.

    Google Scholar 

  12. Miele, A., Wang, T., Heideman, J. C., andSharma, J. N.,Wave Parameter Identification Problem for Ocean Test Structure Data, Part 2, Discrete Formulation, Journal of Optimization Theory and Applications, Vol. 44, No. 3, pp. 453–484, 1984.

    Google Scholar 

  13. Haring, R. E., andSpencer, L. P.,The Ocean Test Structure Data Base, Proceedings of the ASCE Conference on Civil Engineering in the Oceans IV, San Francisco, California, pp. 669–683, 1971.

  14. Haring, R. E., Shumway, D. H., Spencer, L. P., andPearce, B. K.,Operation of an Ocean Test Structure, European Offshore Petroleum Conference and Exhibition, London, England, pp. 167–176, 1978.

  15. Kinsman, B.,Wind Waves, Prentice-Hall, Englewood Cliffs, New Jersey, 1965.

    Google Scholar 

  16. McCormick, M. E.,Ocean Engineering Wave Mechanics, John Wiley and Sons, New York, New York, 1973.

    Google Scholar 

  17. Le Mehaute, B.,An Introduction to Hydrodynamics and Water Waves, Springer-Verlag, Berlin, Germany, 1976.

    Google Scholar 

  18. Sarpkaya, T., andIsaacson, M.,Mechanics of Wave Forces on Offshore Structures, Van Nostrand Reinhold Company, New York, New York, 1981.

    Google Scholar 

  19. Pawsey, S. F., andDello Stritto, F.,Improved Wave Kinematics from Wave Staff Array Records, Paper No. 4587, Offshore Technology Conference, Houston, Texas, 1983.

  20. Davis, R. E., andRegier, L. A.,Methods for Estimating Directional Wave Spectra from Multi-Element Arrays, Journal of Marine Research, Vol. 35, No. 3, pp. 453–477, 1977.

    Google Scholar 

  21. Borgman, L. E.,Directional Wave Spectra from Wave Sensors, Ocean Wave Climate, Edited by M. D. Earle and A. Malahoff, Plenum Press, New York, New York, pp. 269–299, 1979.

    Google Scholar 

  22. Rice, J. R.,Numerical Methods, Software, and Analysis, IMSL Reference Edition, McGraw-Hill Book Company, New York, New York, 1983.

    Google Scholar 

  23. Noble, B., andDaniel, J. W.,Applied Linear Algebra, Chapter 8, Prentice-Hall, Englewood Cliffs, New Jersey, 1967.

    Google Scholar 

  24. Lawson, C. L., andHanson, R. J.,Solving Least Squares Problems, Prentice-Hall, Englewood Cliffs, New Jersey, 1974.

    Google Scholar 

  25. Eykhoff, P., Editor,Trends and Progress in Systems Identification, Pergamon Press, Oxford, England, 1981.

    Google Scholar 

  26. Dongarra, J. J., Moler, C. B., Bunch, J. R., andStewart, G. W.,LINPACK: User's Guide, SIAM, Philadelphia, Pennsylvania, 1979.

    Google Scholar 

  27. Strang, G.,Linear Algebra and Its Applications, Academic Press, New York, New York, 1976.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Additional information

This work was supported by Exxon Production Research Company, Houston, Texas. This paper is based on Refs. 1–6 and is a continuation of the work presented in Refs. 7–12.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Miele, A., Wang, T., Zhao, Z.G. et al. Decomposition techniques for the ocean wave identification problem. J Optim Theory Appl 51, 1–39 (1986). https://doi.org/10.1007/BF00938601

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00938601

Key Words

Navigation