• Spatial Information Research
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• v.21 no.1
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• pp.45-52
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• 2013

Recently 3D surveying is recommended to manage underground facilities systematically before refilling of site operation. As the demand of realtime localization increases, cost reduction and consistent data construction which are realizable by using one man surveying method with unmanned target, are necessary for constructing DB of all sorts of the underground facilities with more speediness and correctness. This study sets a goal to develop a new type of surveying target which allows realtime localization to be performed by one man, through making an optimum reflector(triangle, quadrangle, and semispherical shape) by using the retro-reflection principle of optical prism which is being used for surveying currently. The new surveying target makes realtime surveying possible. To check reliability of its data, the accuracy is compared with surveying coordination of total station for each type in a quantitative method. In the result, the usefulness of the reflector for Underground Facilities localization is proved. Thus the foundation for underground DB construction conducted by one man is established for acquisition of 3D location information in more efficient way through using unmanned target.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.3
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• pp.223-230
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• 2007

As the centralization of city, underground facilities is increasing and being more important. Although the importance of underground facilities map has been emphasized, there were many accidents related underground facilities. The inaccuracy of existing data and the carelessness of management caused many accidents. It is very important to update and to have high quality accuracy of underground facilities maps. But the underground facilities maps are mapped and updated by each institutes. So it is difficult to verify the accuracy of the data. In this study, Field Test is performed to analyze the horizontal accuracy of existing maps using Electromegnetic Induction Method, Total Station and GPS. Surveying of underground facilities in Seoul was performed for 6 institutes of underground facilities during 3 years. The aim of this study is to verify the horizontal accuracy of data and to improve the accuracy of underground facility maps. As the result of analysis, the horizontal accuracy of 6 underground facilities management institutes is 73 cm(2004), 78 cm(2005) and 75 cm(2006).

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.4
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• pp.164-173
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• 2021

Recently, as underground space safety issues such as sink hole, ground subsidence and damage to old underground facilities have been increasing in urban areas, the precise management of underground facilities ins more required. Thus, this study developed a function to that, visualize on Integration Map of Underground Geospatial Information a real-time survey data of underground facilities acquired on site or underground facility survey data acquired through on-site survey after underground facility exploration and developed a function convert to surveying-results. In addition, using the on-site survey performance utilization function in connection with the Integration Map of Underground Geospatial Information developed through this study, the surveying -results obtained with the Total-station at the water pipeline burial construction site in Eunpyeong-gu, Seoul are visualized on the Integration Map of Underground Geospatial Information and On-site verification was performed by converting spatial-information performance files and transmitting the Integration Map of Underground Geospatial Information to the mobile center. Based on this, it was possible to verify the work procedure using the surveying-results in the area where the Integration Map of Underground Geospatial Information was built, and to review the direction of future improvement directions.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.4
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• pp.343-350
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• 2022

The computerization project for underground facilities in Korea began in earnest after the city gas explosion in Seoul in 1994, and the Daegu subway explosion in 1995. As such a large-scale gas explosion accident caused enormous economic loss including human casualties and potential benefits, the need for computerized for efficient management of underground facilities was greatly emphasized in society. Meantime, computerization of underground facilities has been carried out according to the basic plan for building national geographic information system. In this study, problems were identified based on the current status of construction and management of underground facility information, as well as laws and regulations, and directions for establishing quality standards were presented. In addition, construction work standards such as 「Public Survey Work Regulations」, design standards, standard specifications, and technical specifications, gas technology standards, design standards, and communication works so that underground facility information can be linked and utilized in construction work by examining the linkage of the underground facilities, the targets that can be used for quality level information on underground facilities were derived, and a proposal to revise the construction standards was presented. In the future, if the quality standards are established, it is expected that the accuracy and utilization in the construction field will be increased.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.3
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• pp.237-243
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• 2003

The complicated facilities on the ground have begun to be laid under the ground as increasing emphasis on the beauty of cities due to centralization. But, as the kind of the facilities have been concentrated on the narrow area, accidents occur due to the difficulty of maintenance and the inaccuracy of location information. In this study, first we constructed the field test model to compare with the method of underground probing. So, we could know that the electromagnetic induction method and GPR(Ground Penetration Radar) are useful. It was acquired the position information for the underground facilities using a RTK-GPS. As the result, we have analyzed the accurate position of the underground facility and show the way improving accuracy in detecting and surveying comparing with the traditional surveying method. Also, we hope to contribute the effective maintenance and prevention of disasters to the underground facility as using underground facilities 3D position with Arcview and building the DB of exact depth and underground facilities information system.

• Journal of Cadastre & Land InformatiX
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• v.51 no.2
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• pp.35-49
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• 2021

In order to manage the underground spatial information in systematic and effective way, production of an integration underground spatial information map is essential process. The government has been making efforts to expand manage the production of 3D underground spatial integrated map. In recent the GPR is actively used for exploring underground facilities in non-exploring area and sinkhole. For achieving the research objectives presenting the accuracy of verification standard in underground spatial information surveying using GPR, the related legislation standard, the experiment resutls and international criteria have been analyzed. From this research it is found that the accuracy standard has been made by the related academic society(USA) and association(UK) in foreign counties. It is recommended that indicate the verification standard with number and percent together considering the characteristics of GPR.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.1
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• pp.1-14
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• 2022

In order to conduct rapid, accurate and safe surveying at the excavation site, In this study, the possibility of underground facility survey using drones and the expected effect of 3D visualization were obtained as follows. Phantom4Pro 20MP drones have a 30m flight altitude and a redundant 85% flight plan, securing a GSD (Ground Sampling Distance) value of 0.85mm and 4points of GCP (Groud Control Point)and 2points of check point were calculated, and 7.3mm of ground control point and 11mm of check point were obtained. The importance of GCP was confirmed when measured with low-cost drones. If there is no ground reference point, the error range of X value is derived from -81.2 cm to +90.0 cm, and the error range of Y value is +6.8 cm to 155.9 cm. This study classifies point cloud data using the Pix4D program. I'm sorting underground facility data and road pavement data, and visualized 3D data of road and underground facilities of actual model through overlapping process. Overlaid point cloud data can be used to check the location and depth of the place you want through the Open Source program CloudCompare. This study will become a new paradigm of underground facility surveying.

• Journal of the Korean Association of Geographic Information Studies
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• v.20 no.4
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• pp.39-54
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• 2017

Between 1998 and 2010, the computerization of underground facilities was completed in 84 cities. Since 2011, new pipelines have been laid or existing pipelines have been maintained, renovated, and renewed. To measure the exact location and depth of the exposure pipe, a map of underground facilities was created before filling the ground. This method is based on the time when the underground facilities of the National Geographic Information Institute Regulation No. 134 of the National Geographic Information Office revised in 2010 were drafted. The process of the drone taking the video is based on a theoretical basis of ground control points. The method works by removing all ground control points located outside of the error range and re-processing it for calculating the best result. Furthermore, using a drone-based spontaneous measuring method allows workers to obtain a high accuracy underground facilities map in error bound. The proposed method could be used as a new way to standardize the processing.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.525-531
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• 2021

The importance and utilization of underground spatial is increasing due to urban concentration. And so underground spatial information is being built. Because underground spatial information is an important NSDI (National Spatial Data Infrastructure), the accuracy and performance of underground spatial exploration devices used for construction are managed separately. In accordance with the laws and regulations related to spatial information, the government is conducting performance tests for underground facilities surveying equipment. The current performance test site mainly targets metal pipelines, and there is no absolute position surveying inspection system. In this study, test bed model for performance inspection of underground space exploration equipment was presented. The test bed presented in this study can be used as a test site to supplement the limitations of the existing domestic test bed and to verify the performance of the latest equipment.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.56-66
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• 2023

Safety accidents are increasing, such as changes in groundwater levels due to construction work or natural influences, or ground cave-ins caused by soil runoff from old water supply and sewage pipes. In addition, underground facility management agencies must make efforts to improve the accuracy of underground information through continuous investigation and exploration in accordance with the Special Act on Enhanced Underground Safety Management. Accordingly, in this study, we defined the configuration of equipment and data processing method to collect 3D precise exploration underground facility information and developed 3D underground facility information collection technology to ensure accuracy of underground facilities. As a result of verifying the developed technology, the horizontal accuracy improved by an average of 6cm compared to the existing method, making it possible to acquire 3D underground facility information within the error range of the public survey work regulations.