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Bottom profile estimates using passive fathometer processing of ambient noise received by vertical nested array

Title
Bottom profile estimates using passive fathometer processing of ambient noise received by vertical nested array
Author
김정훈
Alternative Author(s)
Kim, Junghun
Advisor(s)
Choi, Jee Woong
Issue Date
2015-08
Publisher
한양대학교
Degree
Doctor
Abstract
A passive fathometer technique utilizes surface-generated ambient noise received by a vertical line array as a sound source to estimate the depth of water-sediment interfaces and sub-bottom layers. This processing method uses the beamforming technique to analyze the vertical component of surface noise and its echo from the bottom. However, in all cases, uniform-spaced arrays were used for beamforming on the end-fire directions, although ambient noise was characterized as a broadband signal. The nested array processing is thus applied to the passive fathometer technique to overcome the drawbacks associated with use of uniform-spaced arrays and effectively cover broadband ambient noise. Ambient noise is measured using a 24-channel, vertical nested line array consisting of four sub-arrays in shallow waters off the eastern coast of Korea. Passive fathometer processing is performed for each sub-array, and the results are combined to form a passive fathometer output for broadband ambient noise. Three types of beamforming techniques, including a conventional method and two adaptive methods, are used in the passive fathometer processing. The results are compared to the depths of the water-sediment interface as measured by an echo sounder.
URI
https://repository.hanyang.ac.kr/handle/20.500.11754/127742http://hanyang.dcollection.net/common/orgView/200000426946
Appears in Collections:
GRADUATE SCHOOL[S](대학원) > ENVIRONMENTAL MARINE SCIENCES(해양환경과학과) > Theses (Ph.D.)
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