• Journal of Korean Society for Geospatial Information Science
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• v.10 no.1 s.19
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• pp.91-100
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• 2002

Recently, many studies on the construction of management system for road facility have been accomplished, and in its process the digital map is used as the essential data for spatial database. But in case where the existing topographical map or completion map of construction data is not sufficient for Data Base construction, the compilation, modification or renewal of digital map should be conflicted with large obstacles. This study intended to extract the road facility information using the image data of various form such as aerial photographs, terrestrial photographs and so on. The terrestrial photographic images are taken by hand-held camera, digital camera and video camera which are widely used and of low price in general. This study used the single frame images only for the raw image data, and the extracted spatial and attribute data from the images are used for modifying and updating the database. In addition, the creating possibility of the digital map in the relative scale using the spatial data extracted from the single images was tried.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.2
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• pp.91-101
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• 2006

Recently, as a part of NGIS project, cultural-assets digital map is produced by cultural properties administration and local autonomous entities. Cultural-assets unified GIS(Geographic Information System) is essential to cultural properties managers and other organizations which are executing land related business for appling it at planning stage. With explosive national land developments, it has been obligated to implement surface survey by the cultural properties protection Art. In this paper, we develope a MSSS(Mobile Surface Survey System) and central GIS management system using CDMA wireless network, real time DGPS and C/S GIS technologies. And we suggest a construction-plan of cultural-assets digital map drawing and managing system by Archaeologist using developed system by this study.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.751-756
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• 2002

Since the operation of the first satellite-based navigation services, satellite positioning has played an increasing role in both surveying and navigation, and has become an indispensable tool for precise relative positioning. However, in some situations, e.g. at a low angle of elevation, the use of satellites for navigation is seriously restricted because obstacles like buildings and mountains can block signals. As a mean to resolve this problem, the quasi-zenith satellite system has been proposed as a next-generation satellite navigation system. Quasi-zenith satellite is a system which simultaneously deploys several satellites in a quasi-zenith geostationary orbit so that one of the satellites always stay close to the zenith if viewed from a specific point on the ground of East Asia. Thus, if a position measurement function compatible with GPS is installed in the quasi-zenith and stationary satellites, and these satellites are utilized together with the GPS, four satellites can be accessed simultaneously nearly all day long and a substantial improvement in position measurement, especially in metropolitan areas, can be achieved. The purpose of this paper is to evaluate the effectiveness of quasi-zenith satellite system on positioning accuracy improvement through simulation by using precise orbital information of the satellites and a three-Dimensional digital map. Through this simulation system, it is possible to calculate the number of simultaneously visible satellites and available area of the positioning without the need of actual observation.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.111-118
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• 2006

The LBS (Location Based Service) location information is the element which is important decides the application of form service, Recently the location accuracy with the method which applies the wireless Internet DGPS improved inside 1 meter Like this. application of the LBS which corresponds In the location accuracy which Improves accurate the Location Information output system development which is accurate stands is essential. In this study which it sees it used 1:5000 digital map MS visual 6.0 Active X controls of the country geography intelligence Personnel and it developed the location information output module of web browser base. The location information output system which is developed it will be able to secure the convenient characteristic of precision and visual program of the digital map simultaneously and the maximum anger of LBS application is expected.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1058-1060
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• 2003

A ground control point (GCP) is a point on the surface of Earth where image coord inates and map coordinates can be identified. The GCP is useful for the geometric correction of systematic and unsystematic errors usually contained in a remotely sensed data. Especially in case of synthetic aperture radar (SAR) data, it has serious geometric distortions caused by inherent side looking geometry. In addition, SAR images are usually severely corrupted by speckle noises so that it is difficult to identify ground control points. We developed a ground point extraction algorithm that has an improved capability. An application of radargrammetry to Daejon area in Korea was studied to acquire the geometric information. For the ground control point extraction algorithm, an ERS SAR data with precise Delft orbit information and rough digital elevation model (DEM) were used. We analyze the accuracy of the results from our algorithm by using digital map and GPS survey data.

• Korean Journal of Computational Design and Engineering
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• v.19 no.3
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• pp.253-262
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• 2014

3D city model, which consisted of the 3D building models and their geospatial position and orientation, is becoming a valuable resource in virtual reality, navigation systems, civil engineering, etc. The purpose of this research is to propose the new framework to generate the 3D city model that satisfies visual and physical requirements in ground oriented simulation system. At the same time, the framework should meet the demand of the automatic creation and cost-effectiveness, which facilitates the usability of the proposed approach. To do that, I suggest the framework that leverages the mobile mapping system which automatically gathers high resolution images and supplement sensor information like position and direction of the image. And to resolve the problem from the sensor noise and a large number of the occlusions, the fusion of digital map data will be used. This paper describes the overall framework with major process and the recommended or demanded techniques for each processing step.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.377-379
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• 2001

Contamination flashover is responsible for insulator electrical failures. Particularly, in Korea, with its perennially dry spring, the first spring rain often cause serious line outages by forming a conductive liquid film on the insulator surface. Rainwater and fog are not normally conductive but unfortunately atmospheric dust deposited on the insulator surface contains soluble salts which may lead to bad condition of insulation by combining watery and salts. Transmission design engineers have used a contamination map drawn on the traditional paper map. But it is not convenient because it does not include the information of Geographic Information accurately. This paper explains the newly developed salt contamination map program using Geographic Information System, which provide accurate geographic information. The program is designed to use four parts of datum, salt contamination levels, 345kV & 154 kV transmission lines, power plants & substations and background map. The digital background map is composed of raster files, the others are done by vector map.

• Journal of the Korean earth science society
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• v.39 no.1
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• pp.46-52
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• 2018

This paper is to study the development of three dimensional Digital Surface Model (DSM) using photogrammetry technique based on self-developed Drone (Unmanned Aerial Vehicle (UAV)). To develop DSM, we selected a study area in Jeju island and took 24 pictures from the drone. The three dimensional coordinates of the photos were made by Differential Global Positioning System (DGPS) surveying with 10 ground control points (GCP). From the calculated three dimensional coordinates, we produced orthographic image and DSM. The accuracy of DSM was calculated using three GCPs. The average accuracy of X and Y was from 8.8 to 14.7 cm, and the accuracy of Z was 0.8 to 12.4 cm. The accuracy was less than the reference accuracy of 1/1,000 digital map provided by National Geographic Information Institute (NGII). From the results, we found that the self-developed drone and the photogrammetry technique are a useful tool to make DSM and digital map of Jeju.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.4
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• pp.109-121
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• 2003

The point of this research is the use of the high resolution satellite image for local government's new address system, as well as spatially field investigation support and base map error finding. Most local governments use scale 1/1,000 and 1/5,000 digital map for base map and field investigation. But field investigator's knowledge insufficiency and the lack of base map's currency make things too difficult from the beginning of the project. As the way of solving this problem, this research offers the use of the high resolution satellite image in new address system with cadence data of digital base map. Until now satellite image is not suitable for our situation because it has low resolution. But this problem was solved for 1m space resolution satellite image and it is being applied wider and wider. Now vector data and Raster data are integrated for complimenting of each weak point. In this study the use of the high resolution satellite image in new address system is expected to improve the quality of the results and reduce the expenses. In addition the satellite image can use local government's fundamental data.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.2
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• pp.57-68
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• 2004

Recently in order to more effectively and scientifically process forest official tasks, which have been focused on documents and inventories, they should be applied with the up-to-date spatial information technologies. Especially, the forest resource information management based on GIS(geographic information system) and aerial orthophoto is expected not only to play an important role as DSS(decision support system) for domestic forest conservation policy and forestry development industry but also to service forest resource information toward people such as the owners of a mountain rapidly. In this study, the important forest information such as digital topography map, digital forest type map, digital forest cadastral map, digital aerial photographs and attribute data were first reprocessed and constructed in DBMS(data base management system). In addition, forest officials could analyze and retrieve forest information by using detail sub-application systems such as forest cadastral retrieval, forest land development information management, reserved forest information management and forest resource information retrieval. For this, the user interface is developed by using Visual Basic 6.0 and MapObjects 2.1 of ESRI based on CBD(component based development) technology. The result of developing this system will not only perform constructing economical forest and better environment but also be the foundation of domestic spatial technology for forest resource management.