• Title/Summary/Keyword: Remote Sensing Exploration

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Analysis of Tidal Channel Variations Using High Spatial Resolution Multispectral Satellite Image in Sihwa Reclaimed Land, South Korea (고해상도 다분광 인공위성영상자료 기반 시화 간척지 갯골 변화 양상 분석)

  • Jeong, Yongsik;Lee, Kwang-Jae;Chae, Tae-Byeong;Yu, Jaehyung
    • Korean Journal of Remote Sensing
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    • v.36 no.6_2
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    • pp.1605-1613
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    • 2020
  • The tidal channel is a coastal sedimentary terrain that plays the most important role in the formation and development of tidal flats, and is considered a very important index for understanding and distribution of tidal flat sedimentation/erosion terrain. The purpose of this study is to understand the changes in tidal channels by a period after the opening of the floodgate of the seawall in the reclaimed land of Sihwa Lake using KOMPSAT high-resolution multispectral satellite image data and to evaluate the applicability and efficiency of high-resolution satellite images. KOMPSAT 2 and 3 images were used for extraction of the tidal channels' lineaments in 2009, 2014, and 2019 and were applied to supervised classification method based on Principal Component Analysis (PCA), Artificial Neural Net (ANN), Matched Filtering (MF), and Spectral Angle Mapper (SAM) and band ratio techniques using Normalized Difference Water Index (NDWI) and MF/SAM. For verification, a numerical map of the National Geographic Information Service and Landsat 7 ETM+ image data were utilized. As a result, KOMPSAT data showed great agreement with the verification data compared to the Landsat 7 images for detecting a direction and distribution pattern of the tidal channels. However, it has been confirmed that there will be limitations in identifying the distribution of tidal channels' density and providing meaningful information related to the development of the sedimentary process. This research is expected to present the possibility of utilizing KOMPSAT image-based high-resolution remote exploration as a way of responding to domestic intertidal environmental issues, and to be used as basic research for providing multi-platform-image-based convergent thematic maps and topics.

Evaluation of Applicability of Sea Ice Monitoring Using Random Forest Model Based on GOCI-II Images: A Study of Liaodong Bay 2021-2022 (GOCI-II 영상 기반 Random Forest 모델을 이용한 해빙 모니터링 적용 가능성 평가: 2021-2022년 랴오둥만을 대상으로)

  • Jinyeong Kim;Soyeong Jang;Jaeyeop Kwon;Tae-Ho Kim
    • Korean Journal of Remote Sensing
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    • v.39 no.6_2
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    • pp.1651-1669
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    • 2023
  • Sea ice currently covers approximately 7% of the world's ocean area, primarily concentrated in polar and high-altitude regions, subject to seasonal and annual variations. It is very important to analyze the area and type classification of sea ice through time series monitoring because sea ice is formed in various types on a large spatial scale, and oil and gas exploration and other marine activities are rapidly increasing. Currently, research on the type and area of sea ice is being conducted based on high-resolution satellite images and field measurement data, but there is a limit to sea ice monitoring by acquiring field measurement data. High-resolution optical satellite images can visually detect and identify types of sea ice in a wide range and can compensate for gaps in sea ice monitoring using Geostationary Ocean Color Imager-II (GOCI-II), an ocean satellite with short time resolution. This study tried to find out the possibility of utilizing sea ice monitoring by training a rule-based machine learning model based on learning data produced using high-resolution optical satellite images and performing detection on GOCI-II images. Learning materials were extracted from Liaodong Bay in the Bohai Sea from 2021 to 2022, and a Random Forest (RF) model using GOCI-II was constructed to compare qualitative and quantitative with sea ice areas obtained from existing normalized difference snow index (NDSI) based and high-resolution satellite images. Unlike NDSI index-based results, which underestimated the sea ice area, this study detected relatively detailed sea ice areas and confirmed that sea ice can be classified by type, enabling sea ice monitoring. If the accuracy of the detection model is improved through the construction of continuous learning materials and influencing factors on sea ice formation in the future, it is expected that it can be used in the field of sea ice monitoring in high-altitude ocean areas.

MAPPING WETLANDS AND FLOODS IN THE TONLE SAP BASIN, CAMBODIA, USING AIRSAR DATA

  • Milne, A.K.;Tapley, I.J.
    • Proceedings of the KSRS Conference
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    • 2002.10a
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    • pp.441-441
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    • 2002
  • In order to ensure a balance between economic development and a healthy Mekong Basin environment supporting natural resources diversity and productivity critical to the livelihood of its 65 million inhabitants, the Mekong River Commission (MRC) has been investigating the use of radar to remotely characterize and monitor the diversity, complexity, size and connectivity of the Basin's aquatic habitats. The PACRIM AIRSAR Mission provided an opportunity to evaluate the usefulness of radar technology to derive information for assessing, forecasting and mitigating possible cumulative and long-term impacts of development on the natural environment and the people's livelihood. This paper presents the results of mapping wetland cover types using multi-polarimetric radar for an area of the north-western corner of the Tonle Sap basin with data acquired from the AIRSAR Mission in September 2000. The implementation of a newly developed segmentation classification routine used to derive the image classification is described and the results of a fieldwork campaign to check the classification is presented.

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Study on the Forest Observation in Kushiro Wetland by using Dual-Frequency and Fully Polarimetric Airborne SAR (Pi-SAR) Data

  • Nakamura Kazuki;Wakabayashi Hiroyuki;Shinsho Hisashi;Maeno Hideo;Uratsuka Seiho;Nadai Akitsugu;Umehara Toshihiko;Moriyama Toshifumi
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.405-409
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    • 2004
  • We chose the Kushiro wetland in Hokkaido, Japan, as a test site to monitor wetland areas. Synthetic aperture radar (SAR) can carry out continuous observation in any weather conditions, and can therefore be used to observe high humidity areas such as wetlands. We applied multi-parameter SAR data (dual-frequency, multi-polarization, and multi-incidence angle) to monitoring the wetland forest. To find the optimum incidence angle and polarization for monitoring the wetland biomass, a simple backscattering model of wetland vegetation was developed and applied to estimate backscattering coefficients for different biomass and surface conditions.

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Tension Wire Sensor of shallow failure detection for the real time slop stabilization (지표변위 감지 센서를 활용한 사면 안전감지 시스템)

  • Chang, Ki-Tae
    • Journal of the Korean Geophysical Society
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    • v.8 no.3
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    • pp.137-143
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    • 2005
  • Early detection of premonitory symptom of slope movement ensures tremendous saving of lives and repair costs from catastrophic disaster. Therefore, it is essential to constantly monitor the performance and integrity of both reinforced and un-reinforced cut slopes. We developed a novel monitoring system by using tension wire sensors. It's advantages are highly sensitivity, simple installation, large displacement measurement, durability of system, capability of remote sensing. Real-time measurement of slope surface movement is shown graphically and it gives a warning when the monitored value exceeds a given threshold level so that any sign of abnormal slope movement can be easily perceived.

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Advances in Imaging of Subsurface Archaeology using GPR

  • Goodman Dean;Nishimur Yasushi;Schneider Kent;Piro Salvadore;Hongo Hiromichi;Higashi Noriaki
    • 한국지구물리탐사학회:학술대회논문집
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    • 2004.08a
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    • pp.8-21
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    • 2004
  • Examples of GPR survey results at a variety of archaeological sites are presented. Several new analyses which include static corrections for the tilt of the GPR antenna are shown for imaging of burial mounds with significant topography. Example archaeological site plans developed from GPR remote sensing of Roman and Japanese sites are given. The first completely automated GPR survey, using only Global Positioning Satellite navigation to create 3D data volumes, is employed for a site in Louisiana to detect lost graves of the Choctaw Indian Tribe.

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Optimum Weight in Spline for Surface Model

  • Shon, Ho-Woong;Oh, Seok-Hoon;Kim, Young-Kyung
    • Journal of the Korean Geophysical Society
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    • v.8 no.1
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    • pp.23-33
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    • 2005
  • The digital surface model (DSM) is used for several purposes in photogrammetry, remote sensing and laser scanned data such as orthoimage production, contours erivation, extraction of height information. Creation of a surface model from point-clouds (3-D sparse points) that can be derived from stereo imagery and range data (e.g. laser scanned data) can be done with several mathematical interpolation models. In this paper, thin-plate-spline (TPS) is used for digital surface modeling. Determination of suitable weight is an important problem in thin-plate function for a surface. The Voronoi algorithm has been proposed as a method for determination of the weight in thin-plate-spline. In this paper, methods has been tested for different surfaces. The results show that thin-plate-spline can be independent of weight.

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An Experimental Study on Density Tool Calibration (광섬유격자 센서를 활용한 사면거동 실시간 안전 진단 시스템)

  • Chang, Ki-Tae;Chung, Kyung-Sun;Kim, Sung-Hwan
    • Journal of the Korean Geophysical Society
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    • v.8 no.1
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    • pp.7-14
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    • 2005
  • Early detection in real-time response of slope movements ensures tremendous saving of lives and repair costs from catastrophic disaster. Therefore, it is essential to constantly monitor the performance and integrity of slope-stabilizing structures such as Rock bolt, Nail and Pile during or after installation. We developed a novel monitoring system using Fiber Bragg Grating (FBG) sensor. It's advantages are highly sensitivity, small dimension and electro-magnetic immunity. capability of multiplexing, system integrity, remote sensing - these serve real-time health monitoring of the structures. Real-time strain measurement by the signal processing program is shown graphically and it gives a warning sound when the monitored strain state exceeds a given threshold level so that any sign of abnormal disturbance on the spot can be easily perceived.

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A GIS Based Decision Support System for Prospects Screening and Evaluation

  • Yanqing, Yu;Xincai, Wu;Ge, Zhang;Xiaoming, Luo;Feng, Li
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.310-312
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    • 2003
  • This paper discusses a GIS based decision support system that provides functions of prospect screening and evaluation in both technical aspects (Volume, structure, trap, reservoir and charge, etc.) and economic aspects (Net present value, Profit / investment Ratio, etc.). The decision support system has been tested in a virtual offshore exploration prospect to facilitate and improve the decision making process. The study represents a test bed for decision makers at all levels to establish prospect screening and evaluation guidelines that may be applicable to other related prospect investment issues.

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