• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.3
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• pp.215-228
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• 2003

National Geography Institute(NGI, National mapping agency) has been producing national basemap in automated process since middle of 1980's toward the systematic and efficient management of national land. In 1995, Korean government initiated a full-scale implementation of the National Geographic Information System(NGIS) Development Plan. Under the NGIS Development Plan, NGI began to produce digital maps in the scales of 1:1,000, 1:5,000, 1:25,000. However, digital maps of 1:250,000 scale, which are currently used for national land planning, were not included in NCIS Development Plan. Also, the existing laws and specifications related to digital maps of 1:250,000 scale are not clearly defined. It is fully appreciated that data dictionary will be a key element for users and generators of digital maps to rectify the existing problems in digital maps as well as to maximize the application of digital maps. There(ore this study proposed a feature classification system, which defines features that should be represented in digital map of 1:250,000 scale, and data dictionary as well.

• Spatial Information Research
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• v.7 no.1
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• pp.119-131
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• 1999

Various digital topographic maps including 1:1,000 and 1:5,000 have been produced for years and these digital maps are expected to serve a wide range of purposes. Most previous research about measuring positional accuracy for digital topographic maps depends int a method that acquires sample points from the tested map and compares to the corresponding known true locations using some statistics. Recently, a simple method for measuring positional accuracy for linear features is introduced but it has substantial problems applying to the spatial features such as roads, railroads, streams represented with double lines on the recently produced 1:1,000 and 1:5,000 digital topographic maps. This study develops and implements an effective method that measures road objects represented in the 1:5,000 digital topographic maps using a conventional GIS software. We also apply this method to a small study area located in Kangnam Gu, Seoul and illustrate the usefulness of this method.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.1
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• pp.21-28
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• 2011

In the existing digital map of the Ver.1.0, it is impossible to make a small scale digital map, which is under the 1/5000 scale map, by using the 1/1000 digital map which is the most large scale one. Because of this reason, the existing digital maps are produced into a 1/1000 and a 1/5000 map by means of two different scale aerial photos. The next generation digital map should be successively related to a small scale digital map based on the most large scale digital one. This is so important from the aspects of data share and the consecutive renewal. Ever since the development of the digital map of the Ver. 2.0, the possibility of making a multi-scale consecutive digital map has been presented and the related research has been done again. The most basic thing in the multi-scale digital maps is to decide the criteria of the generalization between the two scales. In this study, I try to formulate the criteria of the generalization required to make the 1/5000 digital map by using the 111000 digital one. In addition, I by to explore the application possibility of the consecutive renewal by carrying out auto-generalization.

• Journal of Korean Society for Geospatial Information Science
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• v.6 no.1 s.11
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• pp.117-128
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• 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
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• v.16 no.2
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• pp.319-326
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• 1998

In this study, it was tried to experimentally judge the positional accuracy of digital maps, which are being constructed with a vast of investment and national endeavor. Using GPS and Total Station, field surveying to assess the positional accuracy of 1：5,000 digital maps was conducted. According to these results, the digital maps were compared to the real field test. And in order to check the positional accuracy standard of digital maps, theoretical positional accuracy of 1：5,000 digital maps are compared with that from field test data to propose research activities for hereafter positional accuracy standard of digital map.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.4
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• pp.29-38
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• 2016

The maps produced by the NGII(geographical information institute) are composed of 1/1,000, 1/2,500, 1/5,000 large scale maps, 1/25,000, 1/50,000 and smaller scale maps. 1/1,000 digital map, as the most large-scale digital map made by the NGII, has been constructed with the beginning of NGIS(national geographic information System) Project in 1995. However, 1/1000 digital maps have been not produced by the fundamental survey on the basis of systematic planning at the national level, but a lot of parts have been constructed by the public survey for the purpose of the fiscal year of the local governments. Also, these maps have been not regularly updated because of big budget. In this study, we investigated problems related to the construction status, system, and area, and suggested plans that can improve these problems. As the improvement plan, we proposed a nationwide three regionalization for short-term modification and long-term regular update, reset of core downtown boundaries based on topographical features, diversification of budget execution method and an improved execution system.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.1
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• pp.37-44
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• 2003

This study is focused on development of generalization processing for 1/25,000 digital mapping using l/5,000 digital map. The generalization processing for digital map included in spatial and attribute information consists of 3 steps. The first, elimination of layer which is not included in 1/25,000 feature code. The second, classification of 8 feature codes. The third, merging of spatial and attribute information. Therefore using generalization workflow developed in this project, automatic generalization system will develope optimal in the future and also contribute product to small scale digital map and thematic map.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.1
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• pp.49-54
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• 2014

A digital map of 1/5,000 scale provides basic information to be utilized in various businesses, such as in land management, urban information system of a local government, navigation of private sectors and others. 1/5,000 digital map, which contains information of the entire land of South Korea, is performed as a national fundamental map, however, comparing to 1,000 digital map, it has some difficulties in terms of positional accuracy and attribute data for applying in urban areas. Also, since the paradigm of spatial information services has been changed, more accurate positional information and rich attribute information are required for the government businesses and private map services. Particularly, demands for the high precision spatial information based on large-scale digital map is increasing in facility managements due to rapid changes in urban areas and various spatial analyses. For those reasons, this study proposes how to apply and use precise spatial information based on 1/1,000 digital. Firstly, an analysis of legal system related to large-scale digital map and spatial information is conducted in the research. Afterwards, the ways are suggested to improve systematical utilizations of 1/1,000 digital map. We also define existing applications of spatial information in public and private sector, and recommend methodology that can be utilized high precision spatial information.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.3
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• pp.313-321
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• 2002

Supplying high-resolution satellite image, we take much interest in the update and the revision of digital map and thematic map based on the satellite image. This study presented the possibility of the update and the revision to the existing digital map on a scale of l/5,000 and 1/25,000 to take advantage of the IKONOS satellite image. We performed geometric correction to make use of the ground control points of the existing digital map in IKONOS mono-image and created ortho-image by extracting digital elevation model from three dimensional contour data and altitude on the existing digital map. We revised changed features in the method of screen digitizing by overlapping orthorectified satellite image and existing digital map and flawed features of the unchanged area on the satellite images for positional accuracy analysis. As a result, rectification error is calculated at $\pm$3.35m by RMSE. There is a good possibility of update of digital map under the scale of 1/10,000. It is possible to the update of the large scale digital map over the scale of l/5,000, as if we used the method of stereo image and ground control point surveying.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.4
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• pp.331-338
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• 2004

This paper describes capability of utilizing ground control points(GCPs) obtained from 1:1,000 and 1:5,000 digital vector maps to correct image coordinates which have errors due to bais rational polynomial coefficient(RPC) of IKONOS Geo-level stereo images. The accuracy of the bias-corrected images was improved to approximately 4m and 2m in planimetry and height, respectively. The accuracy was also compared with results from using GCPs obtained by GPS surveying. In consequence, bias-compensated IKONOS sereo imagery was evaluated to satisfy generating topographic map 1:10,000.