• Journal of Korean Society for Geospatial Information Science
• /
• v.17 no.3
• /
• pp.57-64
• /
• 2009

Field surveys for the digital map being constructed is being conducted using various work guide books based on the digital mapping internal rule. However, a modification of a rule used for paper map construction is being used for the digital mapping rule, which is causing many problems with the quality of the digital map. Therefore, to construct a high-quality digital map, general standards related to conducting field surveys need to be reviewed, and it's extremely important to construct an accurate digital map based on this. Accordingly, in this study, problems related to conducting field surveys for the construction of the digital map are analyzed in order to establish more suitable field survey standards for constructing an accurate digital map. To this end, work regulations related to construction of a digital map were analyzed, and attribute and field survey data were compared to those of a previously-constructed digital map for analysis. By reflecting opinions of field surveyors and related experts to the results of the analysis, more suitable field survey standards for constructing the digital map were presented.

• Journal of Korean Society for Geospatial Information Science
• /
• v.6 no.2 s.12
• /
• pp.91-103
• /
• 1998

The digital map data of national basemap which will be basic data of the information age is accomplished to produce and are ready to distribute to public. Generally, the quality of digital map is affected to data history, position accuracy, attribute accuracy, logical consistency and completeness. The quality of digital map Is assured to use basic data for the field of various appication. The purpose of this study is to develop automated qualify control program of digital map through analysis type of errors in digital mapping, to determine method of high quality digital mapping. As a results of this study, The automated quality control program of digital map is developed to assure logical consistency and completeness of digital map which is used to principal data in the field of GIS and is determined the process of high quality digital mapping. Also, the results of this study is contributed to quality assrence and accuracy improvement of national basemap digital mapping database.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.17 no.3
• /
• pp.213-223
• /
• 1999

This study provides a improved model of digital basemap production that can efficiently identify and correct the various errors generated in digital map production process. In order to fulfill the requirements that the new model calls for, this study provides a typology of errors by analyzing the errors in digital basemap data. Computer programs for automatic error searching and for checking the correctness of the digital codes in the data have also been developed. Exsiting visual error-checking process has also been analyzed and more systematic process is suggested. As a result, it is found that the improved model of digital basemap production suggested in this study contributes to improving the quality of the digital map database by providing a systematic method for efficient error-searching and correction of digital map data.

• Journal of Korean Society for Geospatial Information Science
• /
• v.6 no.1 s.11
• /
• pp.117-128
• /
• 1998

National digital maps (NDM) produced by diverse production methods through various stages are ready to distribute to public. The position accuracy problems in NDM should be inspected and evaluated to guarantee the quality of NDM. The purpose of this study is 1) to find out factors of impeding accuracy by examining the position accuracy of NDM on scales of 1:1,000 and 1:5,000, 2) to form the technical basis of making accurate digital maps and 3) to increase reliability and practical use of NDM. In this study, we found out 1) obstacles of making accurate mM especially in solving horizontal and vertical location accuracy problems and 2) error sources in production methods as well as stages. These results can be contributed to increase accuracy on modifying and upgrading NDM.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.32 no.2
• /
• pp.77-86
• /
• 2014

As raster-based high quality and resolution spatial information has appeared, 1/1,000 digital map lost either its recognition or uses because of insufficient new modified and updated information. Therefore, this study analyzed the linkage between three-dimensional spatial information and 1/1,000 digital map, and also suggested a modification plan of 1/1,000 digital map, made by three-dimensional spatial information. In fact, some area of Incheon and Busan were presented with the modification plan of 1/1,000 digital map as three-dimensional trial models. These trials reflected possibilities of modification by qualitative and quantitative analysis of 1/1,000 digital map, using three-dimensional object model.

• Journal of Korean Society for Geospatial Information Science
• /
• v.17 no.2
• /
• pp.133-143
• /
• 2009

Next Generation Digital Maps on demand Updating System is a system for setup of efficient on-demand updating system, keeping up-to-date data and conducting high-quality service and efficient management. The system is designed that object-based continuous Digital Maps may have on-demand updating available, as well as the exiting feature-based digital maps, and the relevant development is being done. This study presented some problems and improvement plans related to the system operation, by means of implementing object-based continuous Digital Maps and feature-based digital maps updating test, for the next generation digital maps on demand updating system, in order to contribute to present plans to apply next generation digital maps and to secure competitiveness. And, for the economical efficiency of the next generation digital maps on demand updating system, this study analyzed expenses and benefit resulted from introduction of on demand updating system for 1:5,000 digital maps, intended for National Geographic Information Institute. and the land category which have an effect on the officially assessed land price and it using GIS technology.

• Journal of Korean Society for Geospatial Information Science
• /
• v.8 no.2 s.16
• /
• pp.35-46
• /
• 2000

The digital maps, important data to build NGIS, require different scales in the same area. The organization for producing a digital map tries to find product method for digital map with economical efficiency and quality. The objectives of this study is to develope digital map generalization system to solve above problems. In order to develop this system, the work processing for digital map generalization is established, the analysis of related law and analysis on maps in different scales were performed, and each of digital map generalization algorithms was compared. The result of digital map generalization using this system shows that have a good result about positional accuracy which was evaluated by comparison between the generalized 1/25,000 and the corresponding 1/5,000 digital map. Furthermore, this system reduce the time required for 1/25,000 digital map production and the physical data amount by around 80%. In conclusion, the generalization system developed for this research can be useful for the digital map generalization from large scale to small scale digital map.

• Journal of Korean Society for Geospatial Information Science
• /
• v.18 no.3
• /
• pp.97-104
• /
• 2010

The important factors in a flood simulation are hydrologic data (such as the rainfall and intensity), a threedimensional terrain model, and the hydrologic inundation calculation matrix. Should any of these factors lack accuracy, flood prediction data becomes unreliable and imprecise. The three-dimensional terrain model is constructed based on existing digital maps, current map updates, and airborne LiDAR data. This research analyzes and offers ways to improve the model's accuracy by comparing flood weakness areas selected according to the existing data on flood locations and design frequency.

• Journal of Korean Society for Geospatial Information Science
• /
• v.18 no.4
• /
• pp.141-149
• /
• 2010

Three-dimensional geo-spatial information is important for the efficient use and management of the country and the three-dimensional expression and analysis of urban projects, such as urban plans devised by local governments and urban management. Thanks to the revitalization of the geo-spatial information service industry, it is now being variously used not only in public but also private areas. For the creation of high-guiltily three-dimensional geo-spatial information, emphasis should be placed on not only the quality of the source image and three-dimensional geo-spatial model but also the level of visualization, such as level of detail and texturing. However, in the case of existing three-dimensional geo-spatial information, its establishment process is complicated and its data are not updated frequently enough, as it uses ready-created digital maps. In addition, as it uses Ortho Images, the images exist Relief displacement. As a result, the visibility is low and the three-dimensional models of artificial features are simplified to reach LoD between 2 and 3, making the images look less realistic. Therefore, this paper, analyzed the quality of three-dimensional geo-spatial information created using the three-dimensional modeling technique were applied using Digital photogrammetry technique, using digital aerial photo images by an existing large-format digital camera and multi-looking camera. The analysis of the accuracy of visualization information of three-dimensional models showed that the source image alone, without other visualization information, secured the accuracy of 84% or more and that the establishment of three-dimensional spatial information carried out simultaneously with filming made it easier to gain the latest data. The analysis of the location accuracy of true Ortho images used in the work process showed that the location accuracy was better than the allowable horizontal position accuracy of 1:1,000 digital maps.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.9 no.2
• /
• pp.67-78
• /
• 2006

Local governments began to construct geographic information system to improve government productivity and performance. In support, central government organized a national commission for GIS. The master plan by NGIS has been the base for local government to participate in the construction of GIS at the local level in the under ground facilities management including water and sewers. The challenge faced by sewer facility managers includes controlling 'data accuracy'. The input for sewer data handling for efficient performance in local government requires accurate data. However data manipulation to get the 'good quality' data can be burdensome. Thus, the aim of this research is to provide the appropriate tool to guarantee the high quality of digital data in sewer facility management. It is helpful to pass the data examination by government as well as to insure confidence of decision and data analysis works in local government. In this research, error types of sewer data were classified and pointed the limitation of traditional examination methods. Thus this research suggested more improved method for finding and correcting errors in data input using sewer volume analysis and prediction model as immigrating sewer facility management work to Geographic Information System.