Complex dynamics are studied in the T system, a three-dimensional autonomous nonlinear system. In particular, we perform an extended Hopf bifurcation analysis of the system. The periodic orbit immediately following th...Complex dynamics are studied in the T system, a three-dimensional autonomous nonlinear system. In particular, we perform an extended Hopf bifurcation analysis of the system. The periodic orbit immediately following the Hopf bifurcation is constructed analytically for the T system using the method of multiple scales, and the stability of such orbits is analyzed. Such analytical results complement the numerical results present in the literature. The analytical results in the post-bifurcation regime are verified and extended via numerical simulations, as well as by the use of standard power spectra, autocorrelation functions, and fractal dimensions diagnostics. We find that the T system exhibits interesting behaviors in many parameter regimes.展开更多
A novel technique to determine the position of spacecraft orbits is proposed. The technique is based on the cross-correlation function of HF SAR images and is able to determine the relative position of orbits with an ...A novel technique to determine the position of spacecraft orbits is proposed. The technique is based on the cross-correlation function of HF SAR images and is able to determine the relative position of orbits with an accuracy of - λ/4 or better, where 2 is the wavelength of the HF radar pulse at its center frequency. The performance of the proposed technique was confirmed by simulation which was carried out under the condition of design facts of the SELENE LRS mission. The highly accurate orbit positioning enables precise superposition of HF SAR images so that the inherent mirror image ambiguity problem of HF SAR imaging is resolved to obtain a quality SAR image of the HF band. In addition ambitious 2D-SAR processing would be possible when the above accuracy is available.展开更多
文摘Complex dynamics are studied in the T system, a three-dimensional autonomous nonlinear system. In particular, we perform an extended Hopf bifurcation analysis of the system. The periodic orbit immediately following the Hopf bifurcation is constructed analytically for the T system using the method of multiple scales, and the stability of such orbits is analyzed. Such analytical results complement the numerical results present in the literature. The analytical results in the post-bifurcation regime are verified and extended via numerical simulations, as well as by the use of standard power spectra, autocorrelation functions, and fractal dimensions diagnostics. We find that the T system exhibits interesting behaviors in many parameter regimes.
基金supported by the Basic Research Project, "Development of New Geological Technology for Tracing Earth and Planetary Evolution" of the Korea Institute of Geoscience and Mineral Resources (KIGAM)
文摘A novel technique to determine the position of spacecraft orbits is proposed. The technique is based on the cross-correlation function of HF SAR images and is able to determine the relative position of orbits with an accuracy of - λ/4 or better, where 2 is the wavelength of the HF radar pulse at its center frequency. The performance of the proposed technique was confirmed by simulation which was carried out under the condition of design facts of the SELENE LRS mission. The highly accurate orbit positioning enables precise superposition of HF SAR images so that the inherent mirror image ambiguity problem of HF SAR imaging is resolved to obtain a quality SAR image of the HF band. In addition ambitious 2D-SAR processing would be possible when the above accuracy is available.
