• Korean Journal of Remote Sensing
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• v.17 no.1
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• pp.45-56
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• 2001

To acquire seabed information, the mosaic images of the seabed were generated using Side Scan Sonar. Short time energy function which is needed for slant range correction is proposed to get the height of Tow-Fish to the reflected acoustic amplitudes of each ping, and that leads to a mosaic image without water column. While generating mosaic image, maximum value, last value and average value are used for the measure of a pixel in the mosaic image and 3-D information was kept by using acoustic amplitudes which were heading for specific direction. As a generating method of mosaic image, low resolution mosaic image which is over 1m/pixel resolution was generated for whole survey area first, and then high resolution mosaic image which is generated under 0.1m/pixel resolution was generated for the selected area. Rocks, ripple mark, sand wave, tidal flat and artificial fish reef are found in the mosaic image.

• Korean Journal of Remote Sensing
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• v.11 no.3
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• pp.129-145
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• 1995

SeaBeam2000, a multibeam echo sounder, is a new generation seabed mapping system of which a single swath covers an angular range of -60.deg. to 60.deg. from the vertical direction with 121 beams. It provides high-density and high-quality bathymetric data along with sidescan acoustic data. The purpose of the research is to develop a system for processing multibeam underwater acoustic and bathymetric data using digital signal processing techniques. Recently obtained multibeam echo sounder data covering a survey area in the East Sea of Korea ($37{\circ}$.00'N to $37{\circ}$30'N and $129{\circ}$40'E to $130{\circ}$30'E) are preliminarily processed using the developed system and reproduced in the raster image format as well as three dimensionally visualized form.

• Economic and Environmental Geology
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• v.46 no.6
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• pp.569-580
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• 2013

Co-rich ferromanganese crusts (Fe-Mn crusts) distributed on the seamounts in the western Pacific are potential economic resources for cobalt, nickel, platinum, and other rare metals in the future. Regulations for prospecting and exploration of Fe-Mn crusts in the Area, which enables the process to obtain an exclusive exploration right for blocks of the fixed size, were enacted recently by the International Seabed Authority, which led to public attention on its potential for commercial development. Evaluation and selection of a mining site can be established based on abundance and grade of Fe-Mn crusts in the site as well as topography that should be smooth enough for mining efficiency. Therefore, acquisition of shipboard echo-sounding and acoustic backscatter data are prerequisite to select potential mine sites in addition to visual and sampling operations. Acoustic backscatter data can be used to locate crust-covered areas in a regional scale with the understanding of acoustic properties of crust through its correlation with visual and sampling data. KIOST had collected the topographic and geologic data to assess the resources potential for Fe-Mn crusts in the west Pacific region from 1994 to 2001. However, they could not obtain acoustic backscatter data that is crucial for the selection of prospective mining sites. Therefore, additional exploration surveys are required to carry out side scan sonar mapping combined with seafloor observation and sampling to decide the blocks for application of an exclusive exploration right.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.2
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• pp.225-234
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• 2018

A Multibeam Echo Sounder (MBES) is commonly used for rapid seafloor mapping. We herein present a time-domain integrated system simulation technique for MBES development. The Modeling and Simulation (M&S) modules consist of four parts: sensor array signal transmission, propagation and backscattering modeling in the ocean environment, beamforming of the received signals, and image processing. Also, the simulation employs a ray-theory-based algorithm to correct the reconstructed bathymetry, which has errors due to the refraction caused by the vertical sound velocity profile. The developed M&S technique enables design parameter verification and system parameter optimization for MBES. The framework of this technique can also be potentially used to characterize the seabed properties. Finally, typical seafloor images are presented and discussed.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.4
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• pp.329-338
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• 2022

This paper provides a case study of development testing and evaluation of design goal of Interferometric SAS (Synthetic Aperture Sonar) system that is developing supported by Civil-Military Technology Cooperation Center in offshore fields. For Deep water operating capabilities evaluation, We have surveyed candidate field, bathymetric mapping and target identification over 200 m depth, East Sea. In testing phase, We have provided environmental information of testing field include water column, seabed and weather condition in real time. And to compare excellency of developing InSAS, we have gather commercial imaging sonar system data with same target. This case study will support the Test Readiness Review of future underwater surveillance system developing via investigate marine testing field environment, testing facilities and planning.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.8
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• pp.1222-1229
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• 2010

Compared to conventional high resolution acoustic profiling, ultra high resolution shallow acoustic profiling using parametric echo sounder is limited in penetration, yet it provides resolution suitable for detailed seabed investigation in the shallow waters. The parametric sub-bottom profiler system provides not only the exact determination of water depth, but also the detailed information about sediment layers and sub-bottom structures. Possible applications include dredging project, search of buried pipeline, ship wrecks, and other artificial objects through the detailed mapping of thickness and structure of the upper sedimentary layers. In this study, contaminated sediments were discriminated by the correlation of ultra high resolution profiles with geologic data. In addition, the burial depth of the submarine cable was measured by the interpretation of acoustic anomalies in the profiles.

• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.79-84
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• 2008

Compared to conventional high resolution acoustic profiling, ultra high resolution shallow acoustic profiling is limited in penetration, yet it provides resolution suitable for detailed seabed investigation in the shallow waters. Possible applications include search of buried pipeline, ship wrecks, and other artificial objects through the detailed mapping of thickness and structure of the upper sedimentary layers. In this study, contaminated sediments were discriminated by the correlation of ultra high resolution profiles with geologic data. In addition, the burial depth of submarine cable was measured by the interpretation of acoustic anomalies in the profiles.

• Economic and Environmental Geology
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• v.54 no.6
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• pp.717-731
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• 2021

We analyzed the characteristics of the habitat environment for the Seonam study area in Ulsan, the southern shore of the East Sea using bathymetry and seafloor environment data. The depth of the study area ranges from about 0 m to 23 m. In the west of the study area, the water depth is shallow with a gentle slope, and the water depth becomes deeper with a steep slope in the east. Due to the right-lateral strike-slip faults located in the continental margin of the East Sea, the fracture surfaces of the seabed rocks are mainly in the N-S direction, which is similar to the direction of the strike faults. Three seafloor types (conglomeratic-grained sandy, coasre-graiend sandy, fine-grained sandy) and rocky bottom area have been classified according to the analyses of the bathymerty, seafloor image, and surface sediment data. The rocky bottom areas are mainly distributed around Seaoam and in the northern and southern coastal area. But the intermediate zone between Seonam and coastal area has no rocky bottom. This intermediate area is expected to have active sedimentation as seawater way. The sandy sediments are widely distributed throughout the study area. Underwater images and UAV images show that Cnidarians, Brachiopods, Mollusks are mostly dominant in the shallow habitat and various Nacellidae, Mytilidae live on the intertidal zone around Seonam. Annelida and Arthropod are dominant in the sandy sediments. The distribution of marine organism in the study area might be greatly influenced by the seafloor type, the composition and particle size distribution of the seafloor sediments. The analysis of habitat environment mapping with bathymetry, seafloor data and underwater images is supposed to contribute to the study of the structure and function of marine ecosystem.