• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.154-155
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• 2011

2010년 천리안위성의 성공적인 발사에 따라 인공위성의 활용에 대한 기대가 커지고 있다. 천리안 해양관측위성(GOCI)이외에 아리랑 2호가 현재 운용중인 우리나라 위성들이다. 가까운 시기에 아리랑 5호(2011년 말), 아리랑 3호(2012년), 아리랑 3A호(2013년)가 발사될 예정이다. 즉, 해양적용을 위한 위성환경은 이제부터 준비되고 있다고 볼 수 있다. 대외적으로 보면, 인공위성 자원은 아주 많다. 문제는 이와 같은 자원을 어떻게 활용할 것인가 인데 이의 활용 기술 개발적 측면에서는 많이 소홀한 것이 사실이다. 전세계적으로 이 시스템 개발을 위한 치열한 경쟁이 진행 중에 있다. 이미 소말리아 주변 감시체계는 많은 부분을 위성에 의지하고 있다. 우리나라에서 최초로 위성활용 가능성을 보여준 사건이 허베이스피리트호 원유유출 사고이다. 이 사고는 2007년 12월7일 아침 7시6분경 서해안 만리포 북서쪽 10km 해상에서 크레인을 적재한 1만1800t급 바지선이 정박 중인 홍콩 선적 유조선 허베이 스피리트호(14만6000t급)와 부딪치면서 발생했다. 이와 같은 기름 유출 사고의 경우, 유출 범위를 정확하게 이해하는 것이 중요하다. 거의 준비된 상태가 아님에도 불구하고 12월 8일 아침 최초로 유출된 기름을 모습을 보여주는 위성이미지(광학위성)가 얻어졌다. 하지만 이와 같은 자료가 관련 전문가가 이용할 수 있기까지 많은 시간이 소용되었고, 이 정보를 전달할 수 있는 방법도 없었다. 사실 단순한 이미지가 아니라 지리정보체계를 가진 오염정보를 제공할 방법도 준비도 되어 있지 못한 상황이었다. 본 발표를 통하여, 허베이스피리트호 사고뿐만 아니라, 2011년 6월부터 수개월간 지속된 발해만 오염사고 적용 등 다양한 사례 소개를 하고, 이를 기반으로 해양경찰청에서 업무활용을 위한 방안을 제시한다. 먼저, 해경청의 주요 임무인, 경비, 수색구조, 오염대응 분야별로 현황 분석을 수행하였다. 또한 국외사례에 대한 조사를 한 후, 최종 인공위성 원격탐사기술의 해경청 도입방안에 대한 설계를 실시하였다. 국제적으로 인공위성을 이용한 해양 경비, 수색구조, 오염 모니터링기술 개발이 이루어지고 있으며, 유럽 국가는 시범도입을 진행 중에 있다. 유럽해사안전국(EMSA)은 해양경비 및 수색구조를 위한 선박통항 및 보고 서비스와 오염대비대응(Pollution Preparedness and Response, PPR) 위성 서비스를 회원국에 제공하고 있다. 해양경찰청 임무 수행뿐만 아니라, 해양영토 관리적 측면에서 첨단 위성장비 활용, 선진국형 해상경비 패러다임의 전환 필요성이 크다고 할 수 있다.

• Journal of Korea Water Resources Association
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• v.49 no.4
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• pp.305-314
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• 2016

In this study, a quantitative assessment was carried out in order to identify the agricultural drought in time and space using the Terra MODIS remote sensing data for the agricultural drought. The Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) were selected by MOD13A3 image which shows the changes in vegetation conditions. The land cover classification was made to show only vegetation excluding water and urbanized areas in order to collect the land information efficiently by Type1 of MCD12Q1 images. NDVI and EVI index calculated using land cover classification indicates the strong seasonal tendency. Therefore, standardized Vegetation Stress Index Anomaly (VSIA) of EVI were used to estimated the medium-scale regions in Korea during the extreme drought year 2001. In addition, the agricultural drought damages were investigated in the country's past, and it was calculated based on the Standardized Precipitation Index (SPI) using the data of the ground stations. The VSIA were compared with SPI based on historical drought in Korea and application for drought assessment was made by temporal and spatial correlation analysis to diagnose the properties of agricultural droughts in Korea.

• Spatial Information Research
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• v.21 no.1
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• pp.63-73
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• 2013

Geographic features are reflected in satellite images, which contain characteristic elements. Information on changes can be obtained through a comparison of images taken at different times. If multi-temporal images can be classified through the use of an unsupervised method, this is likely to improve the accuracy of image classification and contribute to various applications. A rule-based image classification algorithm for automatic processing without human involvement has been developed, but it must be verified that its results are not affected by imperfect elements. In this study, Landsat images of Jeju Island were used to carry out a rule-based image classification. The application results were examined for complex cases, including the presence of clouds in the images, different photographed times, and the type of target area, such as city, mountain, or field. The presence of clouds did not affect calculations, and appropriate classification rules were applied, depending on the different photographed times. The expansion of the urban areas of Jeju and the increase of facilities such as vinyl greenhouses in Seoguipo were identified. Furthermore, space information changes and accurate classifications for Jeju Island were obtained. With the goal of performing high-quality unsupervised classifications, measures to generalize and improve the methods employed were searched for. The findings of this study could be used in time-series analyses of images for various applications, including urban development and environmental change monitoring.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.2
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• pp.227-238
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• 2006

Line density index(LDI) was developed to quantify a densely isothermal line rate as standard index in the ocean environment. Theoretical background on the LDI development process restricting index range 0 to 100 was described. And validation test was done for the LDI application condition that total line length is not greater than 1/10 of unit area. NOAA SST(Sea Surface Temperature) data were used for the experimental application of LDI in the South Sea of Korea. Using GIS, $0.1^{\circ}C$ isothermal lines were linearized as vector data form SST raster data, and unit area were built as polygon data. For the LDI calculation, spatial overlapping(line in polygon) was implemented. To analyze the effect of unit area size for the LDI distribution, two cases of unit area size were designed and descriptive statistics was calculated including performing normality test. The results showed no change of LDI's essential characteristics such as mean and normality except for the range of value, variance and standard deviation. Accordingly, it was found that complex structure of thermal front and even smaller scale of front width than unit area size could influence on the LDI distribution. Also, correlation analysis performed between LDI and difference of temperature(${\Delta}T^{\circ}C$), and horizontal thermal gradient(${\Delta}T^{\circ}C/km$) on the front was obtained from linear regression model. This obtained value was compared with the results from previous researches. Newly developed LDI can be used to compare the thermal front regions changing spatio-temporally in the ocean environment using absolute index value. It is considered to be significant to analyze the relationship between thermal front and marine environment or front and marine organisms in a quantitative approach described in this study.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.2
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• pp.20-29
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• 2006

Modeling urban climate caused by land use conversion is critical for human welfare and sustainable development, but has hampered because detailed information on urban characteristics is hard to obtain. With the advantage of satellite observations and the new statistical boundary system, this paper measures the economic and environmental effects of green area loss due to land use conversion in urban areas. To perform this purpose, data were collected from the various sources basic statistical unit data from the National Statistical Office, digital maps from the National Geographic Information Institute, satellite images, and field surveys when necessary. All data (maps and attributes) are built into the geographic information system (GIS). This paper also utilizes Landsat TM 5 imagery of Daegu city to derive vegetation index and to measure average surface temperature. The satellite data were examined using standard image processing software, ERDAS IMAGINE, and the results of the digital processing were presented with ARCVIEW(v.3.3). SAS package was used to perform statistical analyses. This study presents that there exists a strong relationship between land use change and climatic change as well as land price change. Based on results of the analysis, this paper suggests that planners should implement effective tools and policies of urban growth management to detect environmental quality and to make right decisions on policies concerning smart urban growth.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.3
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• pp.57-69
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• 2004

This study developed an ecological mapping technique with GIS database using the analyses of existing ecological survey reports and the change detection on the Nakdong river estuary. The data which are used to establish GIS DB include 2 Landsat TM images on Nov. 31, 1984 and May 17, 1997, 1:25,000 topographical maps established by National Geography Institution and various ecological survey reports published by Busan metropolitan city government. The details for producing ecological map are as follows. At first, the current methods of ecomapping efforts and previous ecological surveys of Nakdong river estuary were carefully examined. Secondly, the land cover maps were created from the classified Landsat images of 1984 and 1997 for the spatiotemporal ecosystem analysis. Thirdly, the ecosystem was evaluated by using GIS ecological database based on the criteria of botany, zoology and water quality etc. Each criteria was reclassified into 3 stages which describe the overall quality of ecological condition. At last, the comprehensive ecological map was suggested as a prototype of ecosystem assesment and management tool with the discussion of further study. The findings of this study would be a milestone for preserving and managing the ecosystem.

• Journal of the Korean Geographical Society
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• v.46 no.1
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• pp.67-80
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• 2011

Choropleth mapping of population distribution is based on the assumption that people are uniformly distributed throughout each enumeration unit. Dasymetric mapping technique improves choropleth mapping by refining spatially aggregated data with residential information. Further, pycnophylactic interpolation can upgrade dasymetric mapping by considering population distribution of neighboring areas, while preserving the volumes of original units. This study proposed a combined solution of dasymetric mapping and pycnophylactic interpolation to improve the accuracy of population density distribution. Specifically, the dasymetric method accounts for the spatial distribution of population within each census unit, while pycnophylactic interpolation considers population distribution of neighboring area. This technique is demonstrated with 1990 census data of the Athens, GA. with land use land cover information derived from remotely-sensed imagery for the areal extent of populated areas. The results are evaluated by comparison between original population counts of smaller census units (census block groups) and population counts of the grid map built from larger units (census tracts) aggregated to the same areal units. The estimated populations indicate a satisfactory level of accuracy. Population distribution acquired by the suggested method can be re-aggregated to any type of geographic boundaries such as electoral boundaries, school districts, and even watershed for a variety of applications.

• Spatial Information Research
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• v.20 no.6
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• pp.129-137
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• 2012

For construction project in extreme cold region, it is essential to establish basic data on the site such as topographical data from the early stage of construction of planning and designing, and it is needed to frequently perform site investigation when necessary. However, extreme cold regions are characteristic of being at long distance and difficult in approaching, and special regions such as Antarctica, in particular, are hard to conduct site investigation. Although a site investigation may be conducted, those who can visit Antarctica are sufficiently limited so that most of the staff may participate in construction without knowledge of the site and increase the risk of errors in decision making or designing. In order to resolve such problems, the authors in this study identified methods of building wide-area topographical data and bedrock classification data of exposed areas via remote sensing and of building precise topographical data on the construction site. Also, the authors attempted to present methods by which such data can be managed and visualized integrally via three-dimensional GIS technology and all the participants in construction can learn sense of field and conduct necessary analysis as frequent as possible. The areas around the Jangbogo Antarctic Station were selected to be the research area for conducting effective integrational management and three-dimensional visualization of various spatial data such as wide-area digital elevation model, ortho-images, bedrock classification data, local precise digital elevation model, and site images. The results of this study may enable construction firms to analyze local environments for construction whenever they need for construction in extreme cold regions and then support construction work including decision making or designing.

• Proceedings of KOSOMES biannual meeting
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• 2004.11a
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• pp.43-47
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• 2004

Two different sensors (here, KOMPSAT and RADARSAT) are considered for ship detection, and are used to delineate the detection performance for their data The experiments are set for coastal regions of Mokpo Port and Ulsan Port and field experiments on board pilot boat are conducted to collect in situ ship validation information such as ship type and length This paper introduce mainly the experiment result of ship detection by both RADARSAT SAR imagery and land-based RADAR data, operated by the local Authority of South Korean, so called vessel traffic system (VTS) radar. Fine imagery of Ulsan Port was acquired on June 19, 2004 and in-situ data such as wind speed and direction, taking pictures of ships and natural features were obtained aboard a pilot ship. North winds, with a maximum speed of 3.1 m/s were recorded Ship's position, size and shape and natural features of breakwaters, oil pipeline and alongside ship were compared using SAR and VTS. It is shown that KOMPSAT/EOC has a good performance in the detection of a moving ship at a speed of kts or more an hour that ship and its wake can be imaged. The detection capability of RADARSAT doesn't matter how fast ship is running and depends on a ship itself, e.g. its material, length and type. Our results indicate that SAR can be applicable to automated ship detection for a VTS and SAR combination service.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.2
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• pp.209-216
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• 2018

High-resolution satellite imagery is used in diverse fields such as meteorological observation, topography observation, remote sensing (RS), military facility monitoring and protection of cultural heritage. In satellite imagery, low-resolution imagery can take place depending on the conditions of hardware (e.g., optical system, satellite operation altitude, image sensor, etc.) even though the images were obtained from the same satellite imaging system. Once a satellite is launched, the adjustment of the imaging system cannot be done to improve the resolution of the degraded images. Therefore, there should be a way to improve resolution, using the satellite imagery. In this study, a super resolution (SR) algorithm was adopted to improve resolution, using such low-resolution satellite imagery. The SR algorithm is an algorithm which enhances image resolution by matching multiple low-resolution images. In satellite imagery, however, it is difficult to get several images on the same region. To take care of this problem, this study performed the SR algorithm by calibrating geometric changes on images after applying automatic extraction of feature points and projection transform. As a result, a clear edge was found just like the SR results in which feature points were manually obtained.