| Autor: |
Gao, J.B., Hwang, S.K., Chen, H.F., Kang, Z., Yao, K., Liu, J.M. |
| Předmět: |
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| Zdroj: |
AIP Conference Proceedings; 2003, Vol. 676 Issue 1, p154, 8p |
| Abstrakt: |
Sea clutter is the backscattered returns from a patch of the sea surface illuminated by a radar pulse. The amplitude waveforms of sea clutter and indoor radio propagation are very complicated. Can the apparent randomness of these waveforms be attributed to be generated by low-dimensional chaos? Based on the assumption that a chaotic attractor is characterized by a non-integer fractal dimension and a positive Lyapunov exponent, Haykin et al (1992) concluded that sea clutter while Tannous et al (1991) concluded that indoor radio propagation data were chaotic. However, a numerically estimated non-integral fractal dimension and a positive Lyapunov exponent may not be sufficient indication of chaos. Other researchers have also indirectly questioned the chaoticness of the sea clutter. We employ a more stringent criterion for low-dimensional chaos developed by Gao and Zheng (Phys. Rev. E, 1994) to study a two minute duration sea clutter data provided by Haykin, and indoor radio propagation data measured at UCLA, and show that these data are not chaotic. We carry out a multifractal analysis and find that sea-clutter data can be modeled as multiplicative multifractals with a lognormal envelope distribution, while the radio propagation data can be modeled as a weak multifractal in the sense of structure function technique. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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