Abstract
The frequency-domain analysis is commonly used to determine ship-motion characteristics, such as transfer functions and Response Amplitude Operators (RAOs). The Discrete Fourier Transform (DFT) has been the most widely used technique to conduct such an analysis. Nevertheless, application of the DFT is not always desirable because of leakage. This problem cannot be eliminated unless the frequency content of a signal is known and all frequency components are rational multiples of each other. In this paper, we apply a recently developed closed-form decomposition technique, called the circular-hyperbolic decomposition (CHD), to estimate the RAOs of coupled heave and pitch motions using evenly sampled discrete ship-motion data. We show the advantages of the new technique over the DFT when leakage is present. We also introduce enhancements to the CHD in terms of a decimation parameter and a generalization for multiple signals. The results show that it is a promising technique.
Original language | English |
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Pages (from-to) | 103-110 |
Number of pages | 8 |
Journal | Journal of Ship Research |
Volume | 45 |
Issue number | 2 |
State | Published - Jun 2001 |