OPTIMAL ESTIMATION OF SHIP'S ATTITUDES AND ATTITUDE RATES

Estimation of ship rotational motions induced by ocean waves plays a central role in many navigation and fire control applications. Inertial-type instruments are available which give good measurements of the attitude, but some form of signal processing is necessary to obtain angular rates or predict attitudes. Using optimal moving-average (or transversal) filters, good estimates of attitude rates as well as predictions of these values can be obtained. Filter parameters can be changed adaptively to maintain good performance as the ship changes heading or velocity. The problem of designing these optimal filters is examined and numerical results are given for a particular set of conditions. Two implementations of the adaptive filter are discussed. One is based on a recursive estimation of the process autocorrelations, with the filter coefficients recomputed at periodic intervals or whenever nonstationary conditions are detected. The second implementation is based on B. Widrow's LMS algorithm. Both alternatives for the adaptive filter implementation are reasonable in terms of their computational requirements. The steady-state performance analysis can be considered to be a lower bound on the errors incurred by an adaptive filter.

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  • Corporate Authors:

    Institute of Electrical and Electronics Engineers (IEEE)

    3 Park Avenue, 17th Floor
    New York, NY  United States  10016-5997
  • Authors:
    • Prado, G
  • Publication Date: 1979-4

Media Info

  • Features: References;
  • Pagination: p. 52-59
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00303731
  • Record Type: Publication
  • Source Agency: Engineering Index
  • Files: TRIS
  • Created Date: Feb 11 1980 12:00AM