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URN etd-0727104-160908 Statistics This thesis had been viewed 2086 times. Download 808 times. Author Hsuan Liu Author's Email Address No Public. Department Communication Engineering Year 2003 Semester 2 Degree Master Type of Document Master's Thesis Language English Page Count 57 Title A TIME-DOMAIN DEBRIS FLOW RADAR BASED
ON HIGH-SPEED MICROWAVE EXCITATION
Keyword TIME-DOMAIN DEBRIS FLOW RADAR HIGH-SPEED MICROWAVE HIGH-SPEED MICROWAVE TIME-DOMAIN DEBRIS FLOW RADAR Abstract ABSTRACT
The purpose of this thesis is to employ the electromagnetic wave to develop a
set of system and estimation method for monitoring remotely water content changes
in the soil of mountains. It is often difficult to make soil moisture content
measurements as a function of depth. Currently, the currently used equipments and
methods need to touch the soil directly while sampling, in this way it becomes
impractical with respect to a remote-monitoring purpose.
In this thesis, for the purpose of repeating measurements and application of
electromagnetic wave that can transmit into the soil, a set of remote time domain
radar system is designed. Its frequency is in 4GHz. To analyze the characteristics of
this system, one firstly utilizes this system to examine the soil moisture content
samples. By transmitting the electromagnetic wave into soil, the reflected signals in
time domain are transformed into spectral signals by Fourier Transform theory. By
observing the spectral change, one can estimate the soil moisture content, or the depth
of the water layer in soil. Further, in computer simulation, soil is divided into layers
and each layer is supposed as different medium. By changing their dielectric
constants and the depth of water layer in the soil, we analyze and discuss the reflected
signal to guess the relationship between the dielectric constant of soil and water
Finally, for a qualitative analysis, we use neural network to seek the model
curves that show the reflected wave change due to the soil water content change.
The measured data from the sampling soil can be the database of neural network, after
training, it is able to estimate the curve changes of the soil moisture content. This
shows that the algorithm based on neural network can be applied in estimating the
parameters of the soil.
Advisor Committee Chi-Fang Huang - advisor
Ke-Fan Liu - co-chair
The-Nan Chang - co-chair
Files Date of Defense 2004-07-13 Date of Submission 2004-07-27