• Geophysics and Geophysical Exploration
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• v.26 no.3
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• pp.103-113
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• 2023

In the oil and gas exploration market, various cableless seismic systems have been developed as an alternative to improve data acquisition efficiency. However, developing such equipment at a small scale for academic research is not available owing to highly priced commercial products. Fortunately, building and experimenting with open-source hardware enable the academic utilization of cableless seismic equipment with relatively low cost. This study aims to develop a cableless seismic acquisition module using Arduino. A cableless seismic system requires the combination of signal sensing, simple pre-processing, and data storage in a single device. A conventional geophone is used as the sensor that detects the seismic wave signal. In addition, it is connected to an Arduino circuit that plays a role in implementing the processing and storing module for the detected signals. Three main functions are implemented in the Arduino module: preprocessing, A/D conversion, and data storage. The developed single-channel module can acquire a common receiver gather from multiple source experiments.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.4
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• pp.305-313
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• 2000

To determine detection capabilities of locating steel bars and delamination inside concrete, commercially available nondestructive testing (NDT) equipments have been tested. The equipments include two radar systems and two electromagnetic method systems. The inclusions are a 19 mm diameter steel bar and 50 mm thick delamination embedded at different cover depths from the surface of concrete specimens. For the steel bar, attempts were made to determine the size of the bars by changing the diameter of the bars. A sample result of measuring horizontal spacing between doubly reinforced bars is presented in this paper. Experimental results on various measurement cases are discussed. Application of numerical modeling technique for the simulation of radar measurements and improved output display of radar measurements are also presented.

• Journal of the Korean Geophysical Society
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• v.5 no.2
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• pp.99-109
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• 2002

Among the geophysical exploration methods, electromagnetic method(EM) has the broadest range of instrumental systems and remarkable range of applications. There are a lot of available techniques and instruments which have different depth of investigation and resolution depending on the operating frequency and source-receiver configuration. Furthermore, it is very easy to apply on the engineering and environmental problems since modern EM equipments are remarkably portable, considering their sophistication. Even though electromagnetic theory is very complex and not easy to understand, rapid avances in recent computer technology have made it possible to conduct accurate forward modeling and inversion of various EM exploration data. Here, we are going to provide brief theoretical principles, survey techniques and case histories of some selected EM methods that can be applied to geotechnical and environmental problems in Korea.

• 한국지구물리탐사학회:학술대회논문집
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• 1999.08a
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• pp.37-47
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• 1999

Among the geophysical exploration methods, electromagnetic (EM) survey must have the broadest range of instrumental systems and remarkable range of applications. There is a plethora of available techniques and instruments, and the depth of investigation and resolution are highly dependent on the particular systems used according to their operating frequency and source-receiver configuration. This diversity of EM systems, however, provides a wide range of instruments or methodologies to choose in order to select the most appropriate tool for the task in hand. This rather than being a disadvantage, would be a major strength of EM methods. Modern EM equipments are remarkably portable, considering their sophistication. Coupled with major advances in recent computer technology, accurate modeling and interpretation techniques are on the way of continuous development and upgrade which, in turn, make the EM methods to become much more heavily used, especially for engineering and environmental applications. We aim to provide a brief theoretical principles, survey techniques and case histories of some selected EM methods that can be applied to geotechnical and environmental problems in Korea.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.2
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• pp.209-217
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• 2011

This study incorporate hydroacoustic sampling for bathymetry and sediment survey in Won Cheon reservoir, Suwon city, Korea. Bathymetric and sedimentation surveys were conducted using a echo sounder system and subbottom profiler in the reservoirs. Data were collected using echo sounder systems and subbottom profiler linked to a GPS, to maximize data accuracy and vessel use, and geo-referenced using a DGPS enabling the acoustic data to be used in a GIS. Echo sounder and subbottom survey data were merged within geographic information system(GIS) software to provide detailed visualization and analyses of current depths, pre-impoundment topography, distribution, thickness, and volume estimates of lacustrine sediment, and water storage capacity. These data and analyses are, necessary for development of long term management plans for these reservoirs and their watersheds.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.172-175
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• 2003

This paper deals with the network interface of research and observation instruments in the oceanographic research vessel with an establishment of related database for measured information. The system is implemented to integrated communication network system which allows to effective survey by using real time observation and GUI(Graphic User Interface). The system also consists of the LAN systems and serial interface to link chemical, physical, biological and environmental relations. And, other network service and vessel data service for data communication between vessel and earth station such as INMARSAT-B, WWW service, BBS, E-Mail etc. are needed for integrated communication network system.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.2
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• pp.203-209
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• 2003

In this study, the configuration and tension of a towing cable for side-scan sonar are predicted in an ambient flow and at an unsteady towing condition. The governing equation of three-dimensional dynamic analysis for a flexible cable is solved using a finite difference method. We successfully predict the configuration and tension of a side-scan sonar and designed the towing system. It is found in static analyses that the side-scan sonar must be towed to keep a its stable depth at a reasonable speed. The study also reveals in the transient analyses that the dominant component affecting the top tension is the tangential drag force for the larger towing speed than the critical speed, and the soft weight of a towed instrument for the smaller towing speed than. It should be maneuvered for a towing vessel with good consideration for the impact effect in a cable due to tension peak when a towing speed is suddenly increase. The developed program can be applicable for three-dimensional dynamic analysis of a towing system for various marine survey instruments.

• Geophysics and Geophysical Exploration
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• v.2 no.2
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• pp.77-85
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• 1999

The 3-D seismic research vessel, Tamhae II, was built to raise up the probability of the hydrocarbon discovery in the Korean continental shelf and the first test survey was completed in the East Sea. During the survey, the 240 channel 2-D marine seismic data were acquired by the Korean flag vessel for the first time. Tamhae II has been equipped with source, receiver, recording equipment, and navigation equipment as well as an onboard processing system. The source is composed of four subarrays and each subarray has six airguns. Total airgun volume is 4578 $in^3$. The receiver consists of two sets of 3 km long 240 channel streamer. In the first survey, the successful acquisition of 2-D seismic data was accomplished. From the result of the data processing, we confirmed that the high quality seismic data were acquired. For the high quality data acquisition, technology of survey design and planning, operation of vessel and equipments and systematic quality control should be developed.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.228.2-228.2
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• 2012

본 논문에서는 탑재체자료전송장치의 시험검증을 위한 장비 개발에 관하여 소개 한다. 원격탐사위성에 탑재되는 고성능원격측정센서는 대용량 데이터를 생성하며 탑재체자료전송장치를 통하여 고주파통신에 의해 지상으로 전송된다. 따라서 탑재체자료전송장치의 검증은 전체 인공위성 개발에 있어서 매우 중요하다. 시험검증장비는 송신되는 수신자료를 수신하여 여러 장비로 분배해주는 고주파신호분배모듈, 계측기 및 복조기 등 다양한 장비로 구성된다. 시험검증장비는 고성능 고주파신호 부품, 다양한 전자장비와 이를 통합, 제어 운영하는 다양한 복잡한 소프트웨어가 필요하여 개발이 어렵다. 본 논문에서는 초기 제작 시험검증장비와 최종 제작 시험검증장비 사이의 차이와 성능, 기능의 향상을 위한 설계변경 등을 통하여 이에 대한 어려움을 극복한 과정과 설계 근거와 장비 선택 등 제반사항에 대하여 기술하여 이후 관련 유사장비의 개발에 있어 도움이 되고자 한다.

• Economic and Environmental Geology
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• v.39 no.4 s.179
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• pp.417-426
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• 2006

Data acquisition is as important as data processing and interpretation in the field of marine geophysical exploration. Marine geophysicist, however, may not have enough information in this field because data acquisition method has been mainly developed by the commercial companies manufacturing the equipment. Therefore, the purpose of this paper is to introduce the general data acquisition method and information to help to construct the systematic and effective survey plan. When a survey plan is set up, the most important thing is to select the seismic equipment based on required penetration depth and resolution, and then construct the survey line intervals. Although a line interval varies from the research purposes, it should be narrower than the expected subsurface structures. Also, if 100% coverage of multibeam data is required, line intervals need to be adjusted based on the equipment characteristics. In case of merging with the preexisting dataset like bathymetry, gravity and magnetic, cross-over errors occurred at the each cross point should be removed to avoid any kinds of misinterpretation.