| Budget Amount *help |
¥15,000,000 (Direct Cost: ¥15,000,000)
Fiscal Year 2004: ¥6,100,000 (Direct Cost: ¥6,100,000)
Fiscal Year 2003: ¥8,900,000 (Direct Cost: ¥8,900,000)
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| Research Abstract |
The purpose of this research were the investigation of the microwave scattering characteristics on water surfaces which coexists wind, waves and currents, and the proposal of the sea surface measurement technique by active microwave remote sensing.
First, we generated artificial water surfaces by known wind, currents and waves in an experimental water tank, and we examined the effects of wind, currents and waves on microwave scattering at that surface in detail. Then numerical simulation technique of microwave scattering on the water surface by surface current method was developed to evaluate microwave scattering in the real surface of the sea of more complicated shape, and microwave scattering characteristic at the surface of the sea by the numerical simulation was examined.
As the result, some back scattering characteristics of microwaves on water surface in the following have been obtained.
1)The back scattering strength depends on only the wind velocity, and no effects of currents and waves were.
2)The middle frequency of Doppler spectrum of backscattering microwaves depends on the wind and current velocities.
3)The band width of Doppler spectrum of back scattering microwaves depends on orbital velocity (drift speed of water particle in the surface of the water) of a wave.
By these results, the previous researches have been confirmed, and the relations between Doppler spectrum and wind or waves were cleared. Further, on the basis of these results, the way to the sea surface measurement by active microwave remote sensing has been showed clearly.
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