| Summary: | 碩士 === 國立中央大學 === 太空科學研究所 === 82 === Chung_Li VHF radar has bulit 3 new 4x8 antenna arrays for
observing 100 Km -- 300 Km heigh ionosphere E region and
F region in september 1991. Encoding our transmittion pulses
by 7 bits or 11 bits Barkercode we can get the strong echo
signal from E and F region. In this article, we use the Space
Domain Interferometry(SDI) method to analyze the velocity of
sporadic E irregularities. Considering the vertical
velocityof irregularities which will effect our recived phase
difference between 2 antenna arrays,so we derive a relation
about the target's displacement and phase difference.By the
way,we can use 3 antenna arrays to analyze the velocity of
irregularites in 3 dimension. We find out the typeII
irregularites drift velocity is about 100 m/s ~ 200m/s
westward, and 50 ~ 100 m/s upward. On the other hand, there
are some interesting phenomena existing in the
received echo signals, such as the characteristics
of quadrature signals. Two different distributions of
quadrature signals can be devided from strong echo power &
weak power signals. We make some discussions about the
relations of power, the distribution of quadrature signals,
amplitude, phase, and spectrum.
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