• Title/Summary/Keyword: 지구물리 탐사

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Summarized Reviews on Geodetic Coordinate System and Map Projection for Practitioners in Exploration Geophysics (물리탐사 실무자를 위한 측지 좌표계와 지도 투영의 이해)

  • Lee, Seong Kon
    • Geophysics and Geophysical Exploration
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    • v.19 no.4
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    • pp.236-248
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    • 2016

  • In this review, the basic concepts of geodetic coordinate system and map projection are explained to practitioners in exploration geophysicists to enhance the understanding of geographic and projected coordinate system. The fundamental elements such as earth ellipsoid, geoid, geocentric and geodetic latitudes, rhumb line, and great circle are dealt with in detail. The geocentric and geodetic coordinate systems are also summarized neatly, together with coordinate conversion formulae. In addition, the concept and technique for datum transforms between local and world datum are presented, with special emphasis on Korean Geodetic System.

  • https://doi.org/10.7582/GGE.2016.19.4.236 인용 PDF KSCI

Geophysical and Geochemical Studies for the Saline Water Intrusion under the Paddy Field in Kyoung-gi area, Korea (경기 지역 농경지 하부로의 해수 침투에 관한 지구물리 및 지구화학적 연구)

  • Lee Sang-Ho;Kim Kyoung-Woong;Lee Sang-Kyu
    • Geophysics and Geophysical Exploration
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    • v.2 no.2
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    • pp.96-103
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    • 1999

  • Most of saline water inousions have been diagnosed by geophysical or geochemical approach independently. The objective of this study is to provide the effective method to detect the saline water intrusion on the ground water in the vicinity of seashore using these two methods. Schulumberger sounding, frequency domain electromagnetic sounding and geochemical analysis of ground water were carried out to explore saline water intrusion. Schulumberger sounding was implemented in dry surface condition before irrigation water was introduced into the field, while electromagnetic sounding was carried out in wet ground condition after the irrigation. The purpose of duplicated measurements on the equivalent spot at different times was to investigate the variation of anomaly zone depending on the amount of ground water. It was possible to discriminate the anomalous zone due to high water saturation from the low electric resistivity zone by high salt concentrations through this way. For the verification of the geophysical result, the ground water samples in the study area were collected and analysed at the 23 points near the measuring spots. The groundwater at the spot nearest to the sea water intrusion identified by geophysical method indicates higher salinity than the standard limit concentration for agricultural irrigation water (250 mg/1). Isotope analysis of $D({^2}H)$ vs. is ${^18}O$ and PCA analysis were used to discriminate the anthropogenic pollution from those of high salinity from sea water intrusion.

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A Breakthrough in Sensing and Measurement Technologies: Compressed Sensing and Super-Resolution for Geophysical Exploration (센싱 및 계측 기술에서의 혁신: 지구물리 탐사를 위한 압축센싱 및 초고해상도 기술)

  • Kong, Seung-Hyun;Han, Seung-Jun
    • Geophysics and Geophysical Exploration
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    • v.14 no.4
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    • pp.335-341
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    • 2011

  • Most sensing and instrumentation systems should have very higher sampling rate than required data rate not to miss important information. This means that the system can be inefficient in some cases. This paper introduces two new research areas about information acquisition with high accuracy from less number of sampled data. One is Compressed Sensing technology (which obtains original information with as little samples as possible) and the other is Super-Resolution technology (which gains very high-resolution information from restrictively sampled data). This paper explains fundamental theories and reconstruction algorithms of compressed sensing technology and describes several applications to geophysical exploration. In addition, this paper explains the fundamentals of super-resolution technology and introduces recent research results and its applications, e.g. FRI (Finite Rate of Innovation) and LIMS (Least-squares based Iterative Multipath Super-resolution). In conclusion, this paper discusses how these technologies can be used in geophysical exploration systems.

  • https://doi.org/10.7582/GGE.2011.14.4.335 인용 PDF KSCI