Based on the Kirchhoff approximation for the surfaces with small slopes, the pulse beam wave scattering fromthe onedimensional fractal sea surface with the actual spectrum is studied. The influence of the different fractal dimension, incident angle, and the center frequency on the distributions of the two-frequency scattering cross section is analyzed. The numerical result shows that there exists the largest coherence bandwidth for the two-frequency scattering cross section at the specular direction. The coherence bandwidth will increase with the decrease of the fractal dimension and with the increase of the incident angle and the center frequency, as well. It is also found that the scattering power takes a pulse shape, but with a pulse broadening for the incident power being δ function, this pulse broadening is inversely proportional to the coherence bandwidth.
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