National Geographic Information Institute Research Articles

Implementation of an Automated Code Checking Algorithm Based on Site Analysis

To date, BIM has been primarily utilized in cost and schedule management, an interference check between architectural and structural models and systems based on geometric data in the process of the construction life cycle. However, there is a lack of research that utilizes the information contained in the BIM model to review whether the proposed architectural model is appropriately designed in accordance with each country’s building regulations or building codes or that proposes a model optimized for laws and standards. ‘Building code checking’ is the step of reviewing whether a building designed based on the building codes is suitable for being constructed as a building. However, this process consumes significant time and money and leads to human errors due to the manual review process. This study included implementation of an algorithm based on the Korean building code. In this study, there was the process of selection of codes when architects interpret building codes in common and implementation based on the codes selected. Next, modeling based on DXF files from NGII (National Geographic Information Institute) was applied to the algorithm developed in this study. Last, it includes case studies that compare the outputs of the algorithm with the real buildings, which had received real code checking, to make sure the algorithm in this paper is working properly. The implementation of such an automated system has the potential to significantly improve the efficiency and effectiveness of the building design and construction process. It can help architects to quickly and accurately identify potential legal issues and provide alternative solutions that meet regulatory requirements. This, in turn, can lead to reduced project costs, improved quality of designs, and faster project delivery times.

Driving altitude generation method with pseudo‐3D building model for unmanned aerial vehicles

AbstractSpatial information is geometrical information combined with the properties of an object. In city areas where unmanned aerial vehicle (UAV) usage demand is high, it is necessary to determine the appropriate driving altitude considering the height of buildings for safe driving. In this study, we propose a data‐provision method that generates the driving altitude of UAVs with a pseudo‐3D building model. The pseudo‐3D building model is developed using high‐precision spatial information provided by the National Geographic Information Institute. The proposed method generates the driving altitude of the UAV in terms of tile information, including the UAV's starting and arrival points and a straight line between the two points, and provides the data to users. To evaluate the efficacy of the proposed method, UAV driving altitude information was generated using data of 763 551 pseudo‐3D buildings in Seoul. Subsequently, the generated driving altitude data of the UAV was verified in AirSim. In addition, the execution time of the proposed method and the calculated driving altitude were analyzed.

독도 주변의 바위섬(암초) 분포와 지도제작 실태 분석

This study started with the problem that the number of annexed islands of Dokdo is expressed differently in maps produced by related organizations such as the National Geographic Information Institute, Korea Hydrographic and Oceanographic Agency, and Korea Land and Geospatial Informatix Corporation. Therefore, the purpose of this study is to find out the cause of the problem and to make policy recommendations by analyzing the maps of Dokdo produced by related organizations and private cartographic companies from the time when the lot numbers were first assigned to Dokdo to the present. As a result of the study, first, it is judged that it is unreasonable to call the rocky islands or reefs distributed around Dokdo as annexed islands. Relevant agencies need to clearly distinguish between rocky islands and reefs, and discuss whether to continue or selectively use the name of annexed islands. Second, in some cases, even a lump of rock falling from the mountaintop of Dokdo is counted as an annexed island. Therefore, related organizations should clearly identify the distribution of rocks and reefs around Dokdo. Finally, it is necessary to discuss in depth whether or not to retain the lot numbers assigned to the rocky islands and reefs. Since small rocky islands or reefs may disappear at any time due to weathering or erosion, it is necessary to be cautious about assigning lot numbers to these annexed islands.

로보택시의 정밀 전역 경로 계획을 위한 μ-Lanelet 그래프

Unlike self-driving buses, which have fixed stops, robo-taxis require precise global path planning to reach a target location quickly and accurately. Precisely generating a global path using a Lanelet graph and a starting/ending point graph, proposed in previous studies, are inefficient because they do not consider a position within the lane. Herein, we propose a μ-Lanelet graph for precise global path planning of robo-taxis and a method for converting a high definition roadmap provided by the National Geographic Information Institute into a Lanelet map. In a μ-Lanelet graph, each lane of a Lanelet map is divided into several sections and connected to each other. It is possible to generate an optimal drivable route directly considering multi-lane changes and construction sites only by searching the graph. The validity of the proposed method was verified through a test using a real vehicle in K-City, Hwaseong, Republic of Korea.

Strategic Improvement Plan to Increase the Usability of Coastal Base Maps Throughout Korea

Lee, J.-C.; Koh, Y.-C., and Lee, D.-H., 2021. Strategic improvement plan to increase the usability of coastal base maps throughout Korea. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 395–399. Coconut Creek (Florida), ISSN 0749–0208. The National Geographic Information Institute constructs and supplies coastal base maps containing spatial and geographic information. The main purpose is securing basic data for designing and developing coastal waters. However, there has been no continuous construction of information for all coastal waters in Korea; therefore, detailed and precise coastal water information for each coastal situation cannot be provided. This study introduces a continuous and unified coastal base map for all coastal waters in Korea. The introduced map can be employed to provide coastal water information with high utility, and widely used not only in coastal construction projects but also in various industries related to the spatial development of coastal waters.

Computation of Porosity of Tetrapods as Coastal Activity Place using Aerial and Drone Images

In 2016 and 2019, the death rate from fall accidents at breakwater and tetrapod was 14.2% and 16.3% of whole coastal activity accidents, a higher proportion than other types of accidents. But there is no quantitative basis for assessing the risk of fallen at tetrapod. Thus this study introduces the method of calculating the porosity of tetrapod by image processing. Aerial image of the National Geographic Information Institute (NGII) and drone image was used. The target area was the tetrapod of the breakwater near Korea Maritime and Ocean University, Yeongdo-gu, Busan City, South Korea. We compared porosity results from Otsu threshold and Adaptive threshold methods. The result shows that Adaptive method gives about 2 times difference between aerial and drone image while Otsu method shows 3 times difference. It is revealed that the adaptive method can be applied with porosity measurement for tetrapod.

Accuracy Evaluation of Geoid Heights in the National Control Points of South Korea Using High-Degree Geopotential Model

Precise geoid heights are not as important for understanding Earth’s gravity field, but they are important to geodesy itself, since the vertical datum is defined as geoid in a cm-level accuracy. Several high-degree geopotential models have been derived lately by using satellite tracking data such as those from Gravity Recovery and Climate Experiment (GRACE) and Gravity Field and Steady-State Ocean Circulation Explorer (GOCE), satellite altimeter data, and terrestrial and airborne gravity data. The Korean national geoid (KNGeoid) models of the National Geographic Information Institute (NGII) were developed using the latest global geopotential models (GGMs), which are combinations of gravity data from satellites and land gravity data. In this study, geoid heights calculated from the latest high-degree GGMs were used to evaluate the accuracy of the three GGMs (European Improved Gravity model of Earth by New techniques (EIGEN)-6C4, Earth Gravitational Model 2008 (EGM2008), and GOCE-EGM2008 combined model (GECO)) by comparing them with the geoid heights derived from the Global Navigation Satellite System (GNSS)/leveling of the 1182 unified control points (UCPs) that have been installed by NGII in South Korea since 2008. In addition, the geoid heights derived from the KNGeoid models were compared with the geoid heights derived from the GNSS/leveling of the 1182 UCPs to assess the accuracy of the KNGeoid models in terms of relative geoid heights for further gravimetric geoid determination studies in South Korea. As a result, the EGM2008 model could be selected as the suitable GGM from among the three GGMs for determining a gravimetric geoid model for South Korea.

Impacts of Sea Level Rise and Storm Surge in Yeosu, Korea

Han, D.; Huh, J.; Canh, B.D., and Jin, H.S., 2019. Impacts of sea level rise and storm surge in Yeosu, Korea. In: Lee, J.L.; Yoon, J.-S.; Cho, W.C.; Muin, M., and Lee, J. (eds.), The 3rd International Water Safety Symposium. Journal of Coastal Research, Special Issue No. 91, pp. 446-450. Coconut Creek (Florida), ISSN 0749-0208.The impacts of global warming and climate change are becoming increasingly severe worldwide and associated coastal flooding is damaging infrastructure and causing human casualties. In this study, we simulated the impacts of sea level rise and storm surge obtained from geographic and past typhoon data (obtained from the National Geographic Information Institute and the Meteorological Administration and National Oceanographic Research Institute) to predict flooding in Yeosu, Korea. Digital surface models were generated from airborne laser scanning to accurately simulate the effect of flooding, and we identified areas and infrastructure at high risk from future flood damage using the predicted significant wave height rise and a region-growing algorithm. Finally, the need to develop a regional disaster plan in response to climate change is proposed.

Quality Assessment of Four DEMs Generated Using In-Track KOMPSAT-3 Stereo Images

The purpose of this research was to analyze the quality and characteristics of four digital elevation models (DEMs) generated using in-track Korea Multi-Purpose Satellite (KOMPSAT)-3 stereo images. The sensor modeling methods were based on ground control points (GCPs), the initial rational polynomial coefficients (RPCs), relative adjustment, and the automatic bias-compensation method. The GCPs and check points (CPs) were extracted from the 0.25 m aerial orthoimage and the 5 m DEM provided by the National Geographic Information Institute (NGII). The DEMs had the same resolution as the reference DEM (5 m) and comparative analysis was carried out. The results indicate that when relative adjustment was applied alone (DEM 3), the percentage of matched points with a correlation of 0.8 or more was improved by at least 17% compared to the case where only initial RPCs were used (DEM 2). Although the absolute horizontal position error of DEM 3 could not be eliminated, the relative elevation error at the same position was reduced significantly. Therefore, if the relative positions of DEMs produced at different times can be corrected, they can be used for the detection of changes in altitude. When applying the automatic bias-compensation method (DEM 4) without GCPs, the percentage of matched points with a correlation of 0.8 or more was 70.1%. When GCPs were used (DEM 1), the value was 70.2%, i.e., almost identical to that of DEM 4. The mean difference in resolution among DEMs 1 and 4 was -1.8 ± 3.4 m (median, -1.0 m). The results show that DEMs of sufficient quality can be generated without GCPs. Furthermore, although discrepancies among the DEMs were noted in forest and shadow areas, it is possible to produce a 5~10 m resolution DEM by using additional image processing techniques, such as shadow removal.

Innovative strategy toward mass customization of geospatial information: the case of National Geographic Information Institute in South Korea

Current ready-made geospatial information (GI) production method of National Geographic Information Institute causes issues, including duplications and inconsistencies of data, and low customer satisfaction. This study suggests concept, framework, approach, and strategy for mass customization of GI to tackle the current production method. First, this study defines mass customization of GI as “a method of producing and providing GI that reflects customer needs, based on modularized and standardized geospatial data as source data”. It is to develop modularized and standardized National Geospatial Data (NGD) based on object-oriented database, using this as source data to produce and provide multi-services of GI. Second, this study suggests three phases (i.e., development/update, management/combination, customization/provision) and seven unit tasks (i.e., data acquisition/synchronization, security management, data maintenance, specification-oriented combination, demand survey, demand-oriented combination) as approach to implement mass customization of GI. Third, this study suggests strategy for GI mass customization, including modularization and standardization of NGD and production process, and customization. Fourth, this study confirms high feasibility of the approach and strategy, through discussion on sufficient condition, success factor, and goal achievement for GI mass customization. This study has implication in shifting paradigm of GI production method from ready-made to customization.

GNSS Data Processing and Analysis for Earthquake Disaster Prevention Monitoring

This article describes how an earthquake with highest magnitude 5.8 on the Richter scale occurred in the Gyeongju area on Sep. 12, 2016 since the first seismological observation. In addition, continuous aftershocks have occurred. There is a pressing need for proper earthquake monitoring and prevention systems. This article is intended to apprehend the dislocation and location change of Continuously Operating Reference Station (CORS) caused by earthquake by means of data on CORS of the National Geographic Information Institute (NGII) and suggest effective seismic monitoring methods. Through Precise Point Positioning (PPP) over earthquake occurrence locations, it was possible to determine the dislocation aspects of CORS for TEGN and CHSG near the seismic epicenter. The nationwide Relative Positioning processing of data for 58 CORS from Sep. 1 to Sep. 30 suggested that CORS had not transitioned coordinates due to the earthquake. For the sake of more efficient earthquake observation and monitoring, it is believed that highly frequent GNSS data acquisition and the additional installation of observation devices such as seismometers is required.

Development of a micro-scale CFD model to predict wind environment on mountainous terrain

The installation of an observation system on mountainous terrain is important for the observation of accurate weather information and the effective prediction of pollutant of airborne virus dispersion and mountain disaster, such as a fire or landslide. However, no Korean standard for installation of the mountain meteorological observation system exists. To determine the proper location, height and size of an observation system, a wind environment analysis under various environmental conditions should be conducted; however, field experiments have time and cost limitations. The objective of this study was to develop a micro-scale 3D Computational fluid dynamics (CFD) model to predict the wind environment on mountainous terrain. In our model, the ground surface of the CFD model was classified and designed based on a digital contour map provided by the National Geographic Information Institute (NGII) and a forest type map provided by Korea Forest Service (KFS) in order to simulate air resistance of trees from the study area. The air resistances of trees were realized as porous medium and the porosity coefficients of the trees were determined based on the previous researches. The developed 3D CFD model was validated using a distribution of wind velocity and direction data measured in mountainous terrain.

Machine Learning Classification of Buildings for Map Generalization

A critical problem in mapping data is the frequent updating of large data sets. To solve this problem, the updating of small-scale data based on large-scale data is very effective. Various map generalization techniques, such as simplification, displacement, typification, elimination, and aggregation, must therefore be applied. In this study, we focused on the elimination and aggregation of the building layer, for which each building in a large scale was classified as “0-eliminated,” “1-retained,” or “2-aggregated.” Machine-learning classification algorithms were then used for classifying the buildings. The data of 1:1000 scale and 1:25,000 scale digital maps obtained from the National Geographic Information Institute were used. We applied to these data various machine-learning classification algorithms, including naive Bayes (NB), decision tree (DT), k-nearest neighbor (k-NN), and support vector machine (SVM). The overall accuracies of each algorithm were satisfactory: DT, 88.96%; k-NN, 88.27%; SVM, 87.57%; and NB, 79.50%. Although elimination is a direct part of the proposed process, generalization operations, such as simplification and aggregation of polygons, must still be performed for buildings classified as retained and aggregated. Thus, these algorithms can be used for building classification and can serve as preparatory steps for building generalization.

A theoretical and experimental comparison of the ionosphere‐free L1 pseudorange and the ionosphere‐free linear combination pseudorange by dual‐frequency SBAS users

This study verifies the performance of the ionosphere-free L1 pseudorange for dual-frequency space-based augmentation systems (SBAS) users by both of theoretical analysis and experiments with actual GPS data. Although the dual-frequency pseudorange from ionosphere-free linear combinations is commonly used as a standard method, the ionosphere-free L1 range based on the weighted Hatch filter has advantages in terms of the amplification factor caused by a dual-frequency combination and filter weights optimised by the least-squares method. For the experimental analysis, RINEX data were collected from five National Geographic Information Institute reference stations on the Korean peninsula and used to generate an SBAS correction message following international SBAS specifications. The experimental results show that using the proposed method results in a 29% improvement in the range domain compared with the use of a traditional ionosphere-free linear combination filter. In the position domain, the proposed method shows a horizontal accuracy improvement of 16% after the application of post-processed SBAS orbit/clock corrections w.r.t. the traditional filter. Finally, this study also demonstrates that the accuracy of dual-frequency users can surpass than that of single-frequency SBAS users only if corrections are estimated with ionospheric delay-free measurements in the master station as well.

고도가 다른 저사양 UAV 영상을 이용한 정사영상 및 DEM 제작

기존의 정사영상 제작에서는 고가의 항공기를 이용한 대규모 지역에 대해서만 경제적인 정사영상을 제작할 수 있었으며, 지형지물에 대해 빠르게 변화를 갱신하지 못한다는 단점이 있었다. 하지만 최근 무인항공기(UAV: Unmanned Aerial Vehicle)가 빠른 속도로 발전되고, GPS와 IMU 등의 다양한 센서 탑재로 고가의 항공사진측량을 대체할 수 있다는 평가를 받고 있다. 무인항공기를 이용하여 소규모 지역에 대한 정사영상 지도를 제작 할 경우 신속하게 공간정보를 갱신할 수 있다는 장점을 가지고 있지만 기존 연구의 경우 같은 고도의 영상으로만 정사영상을 제작하여 자료의 중복성과 자료 갱신에 대한 단점이 있다. 본 연구에서는 소규모 경사지역을 대상으로 저가용 무인항공기의 고도가 다른 영상을 통해 정사영상 및 DEM(Digital Elevation Model)을 제작하였다. 검사점에 의한 수평 및 수직 성분의 RMSE는 σ_h = 0.023m, σ_v = 0.049m 의 정확도를 보여 국토지리정보원 수치지도 1/500 축척의 RMSE와 최댓값 허용범위를 만족하였다. 이를 통해 고도가 다른 영상을 이용하여 높은 정확도의 정사영상을 제작할 수 있었으며, 다양한 고도의 자료를 통해 자료의 중복성을 줄이고, 신속하게 공간정보를 제공할 수 있음을 확인하였다. Even though existing methods for orthophoto production using expensive aircraft are effective in large areas, they are drawbacks when dealing with renew quickly according to geographic features. But, as UAV(Unmanned Aerial Vehicle) technology has advanced rapidly, and also by loading sensors such as GPS and IMU, they are evaluates that these UAV and sensor technology can substitute expensive traditional aerial photogrammetry. Orthophoto production by using UAV has advantages that spatial information of small area can be updated quickly. But in the case of existing researches, images of same altitude are used in orthophoto generation, they are drawbacks about repetition of data and renewal of data. In this study, we targeted about small slope area, and by using low-end UAV, generated orthophoto and DEM(Digital Elevation Model) through different altitudinal images. The RMSE of the check points is σ_h = 0.023m on a horizontal plane and σ_v = 0.049m on a vertical plane. This maximum value and mean RMSE are in accordance with the working rule agreement for the aerial photogrammetry of the National Geographic Information Institute(NGII) on a 1/500 scale digital map. This paper suggests that generate orthophoto of high accuracy using a different altitude images. Reducing the repetition of data through images of different altitude and provide the informations about the spatial information quickly.

Teaching Spatial Thinking With The National Atlas of Korea: A Valuable Resource for Advanced Placement Human Geography

The second edition of The National Atlas of Korea (Choe 2015), published in December 2014 by the National Geographic Information Institute (NGII) of South Korea (the Republic of Korea) in both Kore...

저사양 무인항공기를 이용한 소규모 경사지역의 정사영상 및 수치표고모델 제작

Even though existing methods for orthophoto production in traditional photogrammetry are effective in large areas, they are inefficient when dealing with change detection of geometric features and image production for short time periods in small areas. In recent years, the UAV (Unmanned Aerial Vehicle), equipped with various sensors, is rapidly developing and has been implemented in various ways throughout the geospatial information field. The data and imagery of specific areas can be quickly acquired by UAVs at low costs and with frequent updates. Furthermore, the redundancy of geospatial information data can be minimized in the UAV-based orthophoto generation. In this paper, the orthophoto and DEM (Digital Elevation Model) are generated using a standard low-end UAV in small sloped areas which have a rather low accuracy compared to flat areas. The RMSE of the check points is σ H = ±0.12 m on a horizontal plane and σ V = ±0.09 m on a vertical plane. As a result, the maximum and mean RMSE are in accordance with the working rule agreement for the airborne laser scanning surveying of the NGII (National Geographic Information Institute) on a 1/500 scale digital map. Through this study, we verify the possibilities of the orthophoto generation in small slope areas using generalpurpose low specification UAV rather than a high cost surveying UAV.

다중 위성항법시스템 이용조건에 따른 위성측위 성능 분석

Abstract Many studies have been performed since the introduction of GPS in Korea. As a result, positioning usingGNSS was fully proposed. On the other hand, most of these studies focused on accuracy but analytical studies on the GNSS status and the national GNSS infrastructure of Korea are lacking. In this study, the status of multi-constellation GNSS and National Geographic Information Institute's CORS (Continuous Operating Reference Station) were identified for the benefit and direction of GNSS infrastructure enhancement. As a result, it has beenoperating Multi-constellation GNSS, such as GPS, GLONASS, Galileo, COMPASS, and QZSS for surveying. In addition, improvement was presented by the number of satellites, precision, PDOP, etc. through the experiment aboutVRS and RTK using Multi-constellation GNSS. Upgrading the infrastructure for satellite surveying was identified as a priority consideration. In the future, if a Multi-constellation GNSS service is possible in VRS service, the satisfaction of public administration service will improve, which will contribute greatly to the advancement of a surveying infrastructure.

LX 위성측위 인프라기반 네트워크 RTK를 이용한 측위성능 분석

LX 한국국토정보공사 공간정보연구원에서는 2011년부터 LX 위성측위 (GNSS; global navigation satellite system) 네트워크를 구축하고 2014년부터 MAC (master-auxiliary correction) 방식의 네트워크 실시간 이동측위 (RTK; real-time kinematic) 전국망 운영 실험을 하고 있다. 본 연구에서는 LX GNSS 인프라의 구축 현황을 소개하고 LX GNSS RTK 서비스를 이용한 측위 성능 분석을 결과를 제시한다. 측위 성능 분석은 전북 전주, 서울, 그리고 인천에 설치된 지적도근점 중 총 25개를 이용하였으며, 1회 관측, 2회 중복관측, 그리고 5회 중복관측을 수행하였다. 측위 성능 비교를 위하여 한국국토정보공사 MAC과 국토지리정보원 VRS로 측량한 성과를 지적도근점의 고시좌표와 각각 비교하였다. 그 결과, 두 시스템이 평균오차와 표준편차가 1~2cm 수준으로 유사한 성능을 보였다. The Spatial information research institute of the LX Korea land and geospatial informatix corporation manages infrastructure for the LX global navigation satellite system (GNSS), which comprises 30 monitoring stations nationwide. Since 2014, it has conducted network real-time kinematic (RTK) tests using the master-auxiliary concept (MAC). This study introduces the infrastructure of LX GNSS and presents the results of a performance analysis of the LX RTK service. The analysis was based on a total of 25 cadastral topographic control points in Jeonju, Seoul, and Incheon. For each point, performance was measured over one observation, two repeated observations, and five repeated observations. The measurements obtained from LX MAC and the VRS of the National Geographic Information Institute were compared with the announced coordinates derived from cadastral topographic control points. As a result, the two systems were found to have similar performance with average error and standard deviation differing only by 1 to 2 cm.

수치지질도의 세계측지계 좌표변환 (ArcToolbox를 이용한 충주 및 황강리 도폭의 사례)

우리나라에서는 2010년부터 국제적으로 통용되는 세계측지계의 사용을 의무화하였다. 이에 따라 현재 국토지리정보원에서 발행되는 수치지도는 세계측지계 기준으로 제공되고 있다. 그러나 현재도 대부분의 수치지질도는 동경측지계 기준으로 제공되고 있다. 따라서 사용자들은 수치지질도를 이용한 2D/3D 지질공간분석에 있어서 수치지질도의 좌표를 세계측지계로 변환하여 사용할 수밖에 없는 실정이다. 따라서 본 논문에서는 수치지질도의 좌표정의 및 변환에 익숙하지 않은 사용자들을 위해 ArcToolbox를 이용한 동경측지계로의 좌표정의 및 세계측지계로의 좌표변환 방법을 소개하고자 한다. 이때 좌표정의 및 변환의 객관성을 도모하기 위해서 인접한 1:5만 축척의 충주와 황강리의 지질도폭을 예를 들어 사용하였다. 동경측지계 좌표정의에 있어 충주와 황강리 도폭을 각각 동경측지계 중부원점과 동부원점으로 정의하였고, 황강리 도폭을 다시 동경측지계 중부원점으로 변환하여 충주 도폭과 병합하였다. 세계측지계 좌표변환에 있어 병합된 충주 및 황강리 도폭은 다시 세계측지계 중부원점으로 변환하였다. 변환 결과, 병합된 충주와 황강리 도폭은 수치지도(대소 367041) 위치와 정확히 일치하였다. 이와 같은 방법으로 과거에 만들어진 수치지질도의 좌표문제를 효과적으로 해결 할 수 있었다. 따라서 본 논문에서 제시한 좌표정의 및 변환 방법은 향후 다양한 수치주제도들의 2D/3D 지질공간분석시 주제도들의 전처리 과정으로 유용하게 사용될 수 있을 것으로 기대된다. In Korea, the use of world geodetic system(WGS) has been mandated in year 2010. Accordingly, the national geographic information institute(NGIS) provides the digital maps according to the WGS. Nevertheless, most of the digital geological maps are still based on the Tokyo Datum(TD). Therefore, users should conduct 2D/3D geological spatial analysis after converting the coordinates of digital geological maps to WGS. The conversion process is often tedious and troublesome for certain users. Therefore, in this study, the method to transform coordinate from TD to WGS using ArcToolbox is introduced for users not familiar with the process. For a better appreciation, the Chungju and Hwanggang-ri digital sheets of 1:50,000 scale was chosen as an example. Here, Chungju and Hwanggang-ri sheets were defined based on the TD-central origin and TD-east origin, respectively. The two sheets were merged after the transformation of TD-east origin of Hwanggang-ri to the TD-central origin, and eventually transformed to WGS-central origin. The merged map was found to match exactly with the digital map(Daeso 367041). The problem of coordinate determination in previous digital geological maps was solved effectively. The proposed method is believed to be helpful to 2D/3D geological spatial analysis of various geological thematic maps.