• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.2
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• pp.157-164
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• 2011

As high-resolution satellite images have enabled large scale topographic mapping and monitoring on global scale with short revisit time, agile sensor orientation, and large swath width, many countries make effort to secure the satellite image information. In Korea, KOMPSAT-2 (KOrea Multi-Purpose SATellite-2) was launched in July 28 2006 with high specification. These satellites have stereo image acquisition capability for 3D mapping and monitoring. To efficiently handle stereo images such as stereo display and monitoring, the accurate epipolar image generation process is prerequisite. However, the process was highly limited due to complexity in epipolar geometry of pushbroom sensor. Recently, the piecewise approach to generate epipolar images using RPC was developed and tested for in-track IKONOS stereo images. In this paper, the piecewise approach was tested for KOMPSAT-2 across-track stereo images to see how accurately KOMPSAT-2 epipolar images can be generated for 3D geospatial applications. In the experiment, two across-track stereo sets from three KOMPSAT-2 images of different dates were tested using RPC as the sensor model. The test results showed that one-pixel level of y-parallax was achieved for manually measured tie points.

• Current Industrial and Technological Trends in Aerospace
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• v.5 no.2
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• pp.51-57
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• 2007

상용 위성탑재카메라를 이용한 지표면의 고해상도 영상획득은 1990년대부터 세계 각국에서 많은 노력과 투자를 하고 있다. 미국은 이미 해상도 1m급의 IKONOS, Orbview 및 Quickbird 등을 운용하고 있으며 최근에는 해상도 0.5m급 이하의 위성탑재 카메라를 개발하고 있는 것으로 알려졌다. 러시아, 프랑스, 이스라엘, 일본 등도 1m급 탑재카메라를 개발 중이거나 운용중이며 우리나라도 다목적 실용위성 시리즈의 탑재카메라 개발을 통해 고해상도 위성 카메라를 운용 및 개발 중이다. 이러한 개발동향에 따라 고해상도 위성카메라의 광학부품과 구조부품에 대한 기술적 연구와 개발에도 많은 노력이 이루어지고 있는데, 국내에서도 향후 계속되는 국가의 위성탑재카메라 개발계획에 따라 요구되는 핵심 광구조 부품 개발을 위해 대구경 광학 부품이나 구조물에 대해서 단계적인 국내개발을 시작하고 있다. 우선적으로 한국항공우주연구원과 한국표준과학연구원은 연구원간 협력프로그램으로 대구경 우주급 반사경조립체에 대한 국내개발을 진행하고 있으며 우주환경에서의 광학시험에 필요한 관련 시설을 구축하고 있으므로 국내의 위성관련 광구조부품 개발 기술도 획기적으로 향상될 것으로 기대된다.

• Journal of Environmental Impact Assessment
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• v.11 no.4
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• pp.289-309
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• 2002

Solutions of many landscape problems depend on area-wide assessment and interpretation of spatial and physical characteristics over the study area. The authors argue that the public awareness for an area-wide urban landscape appears to be very low due to limited chance to the information. Acknowledging these constraints, an operational, user-friendly information system has been developed by combining internet technology with GIS. In particular, integration among satellite data and digital maps takes advantage of each component, and enables the landscape structure to be visualized, interacted with and deployed all on the Web. The 1m resolution IKONOS data realistically identified the major type of landscape by large scale spatial precision while TM data revealed successfully the major parameters that influence an area-wide spatial structure in the study area. This system would play a crucial role in improving the public awareness for area-wide landscape information if it is operationally introduced into the Government since the highly user-friendly interface based on image maps provides a completely new means for disseminating information for area-wide landscape in a visual and interactive manner to the general public.

• Korean Journal of Remote Sensing
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• v.18 no.4
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• pp.209-220
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• 2002

We carried out studies on SAR image intensity and interferometric phase over oyster sea farms. Strong backscattering was observed in amplitude images, and that was considered as a radar signal double bouncing from horizontal bars. These sea farming structures are not visible in satellite optical images except IKONOS image, so that it demonstrates the value of radar remote sensing as an effective tool in support of sea farm detection. The intensity of the image is sensitive to system parameters including wavelength, polarization, and look direction, but does not correlate to tide height. We found that the strongest backscattering can be obtained by L-band HH-polarization with a look direction perpendicular to the horizontal bar. We also succeeded in generating 21 coherent JERS-1 SAR interferometric pairs over the oyster farms. The general trend of the fringe rate of the interferometric phases appeared to be governed by altitude of ambiguity. The general trend was modeled by an inverse function and removed to have a residual phase. The residual phase showed a linear relation with the tide height. The results demonstrate for the first time that SAR can possibly be used to estimate sea level. However, the r.m.s. error of a regression line is 11.7 cm, and that is so far too large to make reliable assessments of sea level in practical applications. Further studies is required to improve the accuracy specifically using multi-polarization SAR data.

• 한국공간정보시스템학회:학술대회논문집
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• 2004.12a
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• pp.139-143
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• 2004

최근 고 해상도 위성영상정보의 민간 활용에 대한 수요가 증가하면서 기존의 공간 정보를 다루는 여러 응용분야에서 이에 관련된 많은 연구를 하고 있다. 도시교통 환경 분석을 위하여 위성영상정보를 처리하는 과정에 있어서 도로, 건물, 기타 선 구조와 같은 지형지물을 분석하는 과정은 사용자에 따라 주관적일 수 있다. 이러한 배경에서 수학적 그레이 레벨 모폴로지는 하나의 효과적인 접근으로 간주된다. 본 연구에서 지형지물 추출을 위해 윈도우 운영체제에서 실행되는 실질적인 응용 프로그램을 구현하였다. 이 프로그램에서 주요한 지형지물은 그레이 레벨 영상을 이용하여 개방(opening), 폐쇄(closing), 침식(erosion), 팽창(dilation)의 순차적 처리를 통하여 자동적으로 추출된다. 결과적으로, GDPA, 허프 변환 또는 다른 알고리듬들과 비교시 하나의 이점이 된다. 모폴로지 처리와 같이 본 프로그램은 그레이 레벨 값의 범위에 기반하여 지형지물을 추출을 위한 density slicing 기능 또는 주어진 경계치 보다 작은 화소 군집을 제거하는 처리인 'sieve filtering'을 제공한다. 이러한 기능들은 형태학적으로 처리된 결과를 증대하고 지형지물 종류들을 분리하는데 유용하다. 또한 배경의 제거, 잡음 탐지, 도시 환경 원격 탐사에서의 지형지물 특성화에 기여한다. 본 프로그램을 이용하는데 있어서 IKONOS 위성영상을 이용하여 시험 구현하였다. 결과, 다중 경계치 또는 steve filtering을 이용한 그레이 레벨 모폴로지 처리는 복잡한 지형지물과 많은 데이터로 구성된 고해상도 영상 내의 주어진 대상에서 자동적인 처리와 사용자 정의 sieve filtering으로 인한 효과적인 지형지물 추출 방법으로 간주 된다. 시안을 작성 표준화를 위한 첫 단계 시도를 소개하였다.분석 결과는 문장, 그림 및 도표, 장 끝의 질문, 학생의 학습 활동 수 등이 $0.4{\sim}1.5$ 사이의 값으로 학생 참여를 적절히 유도하는 발견 지향적 인 것으로 조사되었다. 그러나 장의 요약은 본문 내용을 반복하는 내용으로 구성되었다. 이와 같이 공통과학 과목은 새로운 현대 사회에 부응하는 교과 목표와 체계를 지향하고 있지만 아직도 통합과학으로서의 내용과 체계를 완전히 갖추고 있지 못할 뿐만 아니라 현재 사용되고 있는 7종의 교과서가 교육 목표를 충분히 반영하지 못하고 있다. 따라서 교사의 역할이 더욱더 중요하게 되었다.괴리가 작아진다. 이 결과에 따르면 위탁증거금의 징수는 그 제도의 취지에 부합되고 있다. 다만 제도운용상의 이유이거나 혹은 우리나라 주식시장의 투자자들이 비합리적인 투자형태를 보임에 따라 그 정책적 효과는 때로 역기능적인 결과로 초래하였다. 그럼에도 불구하고 이 연구결과를 통하여 최소한 주식시장(株式市場)에서 위탁증거금제도는 그 제도적 의의가 여전히 있다는 사실이 확인되었다. 또한 우리나라 주식시장에서 통상 과열투기 행위가 빈번히 일어나 주식시장을 교란시킴으로써 건전한 투자풍토조성에 저해된다는 저간의 우려가 매우 커왔으나 표본 기간동안에 대하여 실증분석을 한 결과 주식시장 전체적으로 볼 때 주가변동율(株價變動率), 특히 초과주가변동율(超過株價變動率)에 미치는 영향이 그다지 심각한 정도는 아니었으며 오히려 우리나라의 주식시장은 미국시장에 비해 주가가 비교적 안정적인 수준을 유지해 왔다고 볼 수 있다.36.4%)와 외식을 선호(29.1%)${\lrcorner}$ 하기 때문에 패스트푸드를 이용하게 된 것으로 응답 하였으며,

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.1
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• pp.1-11
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• 2009

Rapid visualization of flood area of downstream according to the dam effluent in flood season is very important in dam management works. Overlay zone of river bight should be removed to represent flood area efficiently based on flood stage which was modeled in river channels. This study applied drainage enforcement algorithm to visualize flood area considering river bight by coupling Coordinate Operation System for Flood control In Multi-reservoir (COSFIM) and Flood Wave routing model (FLDWAV). The drainage enforcement algorithm is a kind of interpolation which gives to advantage into hydrological process studies by removing spurious sinks of terrain in automatic drainage algorithm. This study presented mapping technique of flood area layer considering river bight in Namgang-Dam downstream, and developed system based on Arcobject component to execute this process automatically. Automatic extraction system of flood area layer could save time-consuming efficiently in flood inundation visualization work which was propelled based on large volume data. Also, flood area layer by coupling with IKONOS satellite image presented real information in flood disaster works.

• Spatial Information Research
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• v.17 no.4
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• pp.431-443
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• 2009

Recently, turbidity problem is one of the hot issues in dam and reservoir management works. Main reason to bring about high density turbid water is sediment yield by rainfall intensity energy. Because existing researches didn't consider diverse types of crops, it was difficult to calculate more accurate soil erosion and sediment yield. This study was evaluated the reduction efficiency of soil erosion and sediment yield using ginseng layer extracted from IKONOS satellite image, and the area and the ratio of ginseng area represented $0.290km^2$ and 0.94%. The reduction efficiency of soil erosion considering ginseng area represented low value in 0.9% using GIS-based RUSLE model, because the area of ginseng was small compared to areas of other agricultural lands. To reflect future land use change, this study was calculated the reduction efficiency of soil erosion and sediment yield by considering many scenarios as kinds of crops of paddy, dry field, orchard, and other agricultural areas convert to the ginseng district. As result of analysis of them according to scenarios, scenario (1) in which dry field was converted to ginseng area and scenario (2) in which fully agricultural lands were converted to ginseng area showed high reduction efficiency as 31.3% and 34.8% respectively, compared to existing research which didn't consider ginseng area. Methodology suggested in this study will be very efficient tools to help reservoir management related to high density turbid water.

• Korean Journal of Remote Sensing
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• v.23 no.2
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• pp.131-135
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• 2007

The tidal channel is influenced by sediment type, grain size, grain composition and tidal currents in tidal flat. The development of tidal channel including density, shape and order can be used to analyze the characteristics of tidal channel. The quantitative investigation to the tidal channel is insufficiency. In this paper, we represented the fractal analysis method according to the quantitatively analysis in tidal channel and compared with the different intertidal channel patterns. The tidal channel was extracted from the IKONOS image of the southern part of the Kanghwa-do. We used the Box-counting method to estimate fractal dimensions for each tidal channel. As a result, the fractal dimension values (D) were 1.31 in the southern Kanghwa-Do. Linear pattern and less dense channel development area had low D values (from 1.0563 to 1.0672). Dendritic pattern and dense channel development area had high D values (from 1.2550 to 1.3016). In other words, fractal dimension values had difference about 0.2 values according to the characteristic of tidal channel development. We concluded that fractal analysis can be able to quantitatively classification in tidal channel.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.2
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• pp.108-120
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• 2008

This paper discusses the prediction of deforestation areas using probability models from forest census database, Geographic information system (GIS) database and the land cover database. The land cover data was analyzed using remotely-sensed (RS) data of the Landsat TM data from 1989 to 2001. Over the analysis period of 12 years, the deforestation area was about 40ha. Most of the deforestation areas were attributable to road construction and residential development activities. About 80% of the deforestation areas for residential development were found within 100m of the road network. More than 20% of the deforestation areas for forest road construction were within 100m of the road network. Geographic factors and vegetation change detection (VCD) factors were used in probability models to construct deforestation occurrence map. We examined the size effect of area partition as training area and validation area for the probability models. The Bayes model provided a better deforestation prediction rate than that of the regression model.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.2
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• pp.119-126
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• 2002

Recently, as advancing the technologies for Web 3D and Virtual Reality, the studies have been progressed actively to provide three dimensional information on the web. Especially, the various applications for providing urban information in 3D space have been developed using EAI(External Authoring Interface) that serves an interface between VRML(Virtual Reality Modeling Language), standard language for embodying virtual reality, and JAVA applet in HTML. In this study, as constructing 3D virtual city information using Digital Map, IKONOS satellite image, VRML and so on, we could provide users which need several information with building location and various urban living information. In addition, applying 3D skills such as texturing, panorama and navigation, users were enabled to perform various route searching and scenery analysis. Finally, to serve urban living information in real time, we designed to search information faster through interfacing database and to update data using ASP(Active Server Page) on web.