• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.3
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• pp.103-114
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• 2013

In this study, we established the ortho mosaic imagery on the Korean Peninsula using KOMPSAT-2 images and conducted an accuracy assessment. Rational Polynomial Coefficient(RPC) modeling results were mostly less than 2 pixels except for mountainous regions which was difficult to select a Ground Control Point(GCP). Digital Elevation Model(DEM) which was made using the digital topographic map on the scale of 1:5,000 was used for generating an ortho image. In the case of inaccessible area, the Shuttle Radar Topography Mission(SRTM) DEM was used. Meanwhile, the ortho mosaic image of the Korean Peninsula was produced by each ortho image aggregation and color adjustment. An accuracy analysis for the mosaic image was conducted about a 1m color fusion image. In order to verify a geolocation accuracy, 813 check points which were acquired by field survey in South Korea were used. We found that the maximum error was not to exceed 5m(Root Mean Square Error : RMSE). On the other hand, in the case of inaccessible area, the extracted check points from a reference image were used for accuracy analysis. Approximately 69% of the image has a positional accuracy of less than 3m(RMSE). We found that the seam-line accuracy among neighboring image was very high through visual inspection. However, there were a discrepancy with 1 to 2 pixels at some mountainous regions.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.3
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• pp.363-373
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• 2010

"Curve number" (CN) indicates the runoff potential of an area. The US Soil Conservation Service (SCS)'s CN method is a simple, widely used, and efficient method for estimating the runoff from a rainfall event in a particular area, especially in ungauged basins. The use of soil maps requested from end-users was dominant up to about 80% of total use for estimating CN based rainfall-runoff. This study introduce the use of soil maps with respect to hydrologic and watershed management focused on hydrologic soil group and a case study resulted in assessing effective rainfall and runoff hydrograph based on SCS-CN method in a small watershed. The ratio of distribution areas for hydrologic soil group based on detailed soil map (1:25,000) of Korea were 42.2% (A), 29.4% (B), 18.5% (C), and 9.9% (D) for HSG 1995, and 35.1% (A), 15.7% (B), 5.5% (C), and 43.7% (D) for HSG 2006, respectively. The ratio of D group in HSG 2006 accounted for 43.7% of the total and 34.1% reclassified from A, B, and C groups of HSG 1995. Similarity between HSG 1995 and 2006 was about 55%. Our study area was located in Sosu-myeon, Goesan-gun including an approx. 44 $km^2$-catchment, Chungchungbuk-do. We used a digital elevation model (DEM) to delineate the catchments. The soils were classified into 4 hydrologic soil groups on the basis of measured infiltration rate and a model of the representative soils of the study area reported by Jung et al. 2006. Digital soil maps (1:5,000) were used for classifying hydrologic soil groups on the basis of soil series unit. Using high resolution satellite images, we delineated the boundary of each field or other parcel on computer screen, then surveyed the land use and cover in each. We calculated CN for each and used those data and a land use and cover map and a hydrologic soil map to estimate runoff. CN values, which are ranged from 0 (no runoff) to 100 (all precipitation runs off), of the catchment were 73 by HSG 1995 and 79 by HSG 2006, respectively. Each runoff response, peak runoff and time-to-peak, was examined using the SCS triangular synthetic unit hydrograph, and the results of HSG 2006 showed better agreement with the field observed data than those with use of HSG 1995.

• The Journal of Engineering Geology
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• v.34 no.3
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• pp.355-366
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• 2024

As the importance of silica is increasing in digital world and other sector, prospecting of silica is the initial process for silica exploration. For prospecting of silica, the Naudanda Quartzite was studied thoroughly. The potential of silica content in the Naudanda Quartzite is presented in very few reports and literatures. Therefore, the study was carried out along the Siddartha Highway and other local roads around the Bhalu Pahad area. The area comprises of mainly phyllite, metasandstone and medium- to coarse-grained orthoquartzite of the Lesser Himalayan metasedimentary sequence. Here orthoquartzite is targeted for the prospecting of silica as quartzite constitutes more than 90% quartz minerals. The study was carried out to prospect the silica resource and compute the mineral reserve in the area. From the route map prepared at 1:2,000-scale along the Bhalu Pahad-Haripala section and columnar section, it is found that the true thickness of the Naudanda Quartzite is 760 m. A geological map was prepared at 1:25,000 scale, and 15 quartzite samples were taken from suitable locations preventing stratigraphical reoccurrence. Five samples were taken randomly from folded zone. Silica grains were counted on the basis of fleet method after thin section preparation of 15 individual samples. More than 95% silica is present on an average. Again, silica content of 5 samples out of 15 were tested chemically and found more than 95% silica concentration. For reserve calculation, silica grade was taken 95% and the reserve was computed on the basis of three cross-sections. It is found that the total volume tonnage is 2.6 billion ton of silica content, and concluded that the silica present in the rock is economic and minable.

• Journal of Korean Society for Geospatial Information Science
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• v.14 no.1 s.35
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• pp.29-36
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• 2006

In the process of location selection, it is assumed that transformer substation socially recognized as a dangerous facility require especially more rigorous and resonable process. This paper implements suitability analysis for optimum location selection of transformer substation in southern Gyeonggi province using AHP(Analytic Hierarchy Process) and spatial analysis of GIS in terms of safety, national land use, economical efficiency and environment preservation. To do this, necessary data from 1/5,000 digital map are extracted a s raster format for suitability analysis and a field investigation also was done. In the procedure of site selection, three candidate zones with 1.5km radius were selected for the whole research area and then through field survey low transformer sites were selected from candidate zones. In the last the appropriateness of selected sites was evaluated. The results of the suitability analysis showed that the first candidate site satisfied the location condition best and other candidate sites generally showed good location condition.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06c
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• pp.55-58
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• 1998

본 논문에서는 음성인식기능을 이용하여 지리정보 검색시스템을 구현하고 그 성능 평가 결과에 관하여 보고한다. 성능평가실험을 위하여 사용한 수치지도 자료는 1:5,000의 대구광역시 수성구의 국가 기본도를 사용하였으며, 이 수치지도에서 속성단어와 제어단어를 포함한 68단어를 음성인식과 지도정보 검색의 대상으로 한다. 또한, 음성인식 결과와 지도자료와의 인터페이스는 OLE Automation 프로그래밍 기법을 이용하였으며, Pentium 150MHz, 64MB 메모리를 가진 개인용 컴퓨터 환경하에서 개발하였다. 성능평가 실험결과 남성 3인이 지도검색용 68단어를 실제 사무실 환경하에서 마이크를 통하여 on-line 테스트하여 평균 98.02%의 인식률을 얻었다. 이사의 결과로부터 음성인식기능을 이용한 수치지도 정보검색 시스템의 실용화 가능성을 확인할 수 있었다.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.509-516
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• 2001

As the first step for the application of seismic landslide hazard maps to domestic cases, two types of hazard maps on Ul-joo from pseudostatic analysis and Newmark sliding block analysis are constructed and comllared. Arcview, the GIS program and the 1:5,000 digital maps of the test-site are used for the construction of hazard maps and tile parameters for the analyses are determined by seismic survey and laboratory tests. The results from the pseudostatic analysis have more conservative values of lower critical slope angles, although the results from the two different analyses have similar tendencies. In detail, with increasing the peak ground acceleration, the difference between the two analyses in the critical slope angle increases, while the difference decreases with increasing the maximum soil depth.

• Journal of Korea Spatial Information System Society
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• v.12 no.1
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• pp.57-65
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• 2010

In this study, disaster damage investigation system was developed using high resolution satellite images and GIS technique to afford effective damage investigation system for widely disaster damaged area. Study area was selected in Bonghwa, Gyungsangbukdo where high magnitude of damages from torrential rain has occurred at July in 2008. GIS DB was built using 1:5,000 topographic map, cadastral map, satellite image and aerial photo to apply for investigation algorithm. Disaster damage investigation system was developed using VB NET languages, ArcObject component and MS-SQL DBMS for effective management of damage informations. The system can finding damaged area comparing pre- and post-disaster images and drawing damaged area according to the damage item unit. Extracted object was saved in Shape file format and overlayed with background GIS DB for obtaining detail information of damaged area. Disaster damage investigation system using high resolution spatial images can extract damage information rapidly and highly reliably for widely disaster areas. This system can be expected to highly contributing to enhance the disaster prevention capabilities in national level field investigation supporting and establishing recovery plan etc. This system can be utilized at the plan of disaster prevention through digital damage information and linked in national disaster information management system. Further studies are needed to better improvement in system and cover for the linkage of damage information with digital disaster registry.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.4_1
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• pp.311-318
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• 2014

The data of buildings and structures take over large portions of the mapping database with large numbers. Furthermore, those shapes and attributes of building data continuously change over time. Due to those factors, the efficient methodology of updating database for following the most recent data become necessarily. This study has purposed on extracting needed data, which has been changed, by using overlaying analysis of new and old dataset, during updating processes. Following to procedures, we firstly searched for matching pairs of objects from each dataset, and defined the classification algorithm for building updating cases by comparing; those of shape updating cases are divided into 8 cases, while those of attribute updating cases are divided into 4 cases. Also, two updated dataset are set to be automatically saved. For the study, we selected few guidelines; the layer of digital topographic map 1:5000 for the targeted updating data, the building layer of Korea Address Information System map for the reference data, as well as build-up areas in Gwanak-gu, Seoul for the test area. The result of study updated 82.1% in shape and 34.5% in attribute building objects among all.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2005.11a
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• pp.81-104
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• 2005

Accurate 3D models in urban areas are essential for a variety of applications, such as virtual visualization, CIS, and mobile communications. LiDAR(Light Detection and Ranging) is a relatively new technology for directly obtaining 3D points. Because Manual 3D data reconstruction from LiDAR data is very costly and time consuming, many researchs is focused on the automatic extraction of the useful data. In this paper, we classified ground and non-ground points data from LiDAR data by using filtering, and we reconstructed the DTM(Digital Terrain Model) using ground points data, buildings using nonground points data. After the reconstruction, we assessed the accuracy of the DTM and buildings. As a result of, DTM from LiDAR data were 0.16m and 0.59m in high raised apartments areas and low house areas respectively, and buildings were matched with the accuracy of a l/5,000 digital map.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.5
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• pp.487-493
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• 2014

A geographic survey, which requires much of working hours in the digital mapping process, is consisted with the complementary survey and the attribute survey of topography and topographic features, and depended on the field survey. In previous research, using the location-based image had been recommended for diminishing the workload of field survey and post processing. For this research, we have developed the hardware and software for gathering and processing the location-based images with referencing results from the previous research. Those Geographic surveys were performed using developed system on 1/5,000 map sheets for Si and Gun area, respectively. The results have been evaluated as the mobile geographic survey system were able to replace the large part of field survey, and also the working hours were decreased by 37.5% at Si area. However, the complementary survey was needed for the attributes of topography and topographic features that were occluded by the parked vehicles or located in the areas without entry of vehicles.