• The Journal of the Korea Contents Association
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• v.18 no.6
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• pp.303-313
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• 2018

The purpose of this study is digitalization of earthwork such as development of 3D terrain analysis platform using latest technologies including unmanned aerial vehicle and terrestrial laser scanner to ultimately achieve earthwork automation. It is necessary to develop related element technologies and to establish regulations so that it can be applied to the domestic construction projects. As a result of pilot project about the earthwork surveying automation technology, it was confirmed that information such as terrain coordinates, soil, boring, and excavation volume is acquired smoothly. In this paper, we investigate related regulations and manuals in Japan and propose the improvement plan of domestic regulation. We plan to study regulations from early to final construction stage, combine with the 'regulation for public surveying', and improve the regulations in detail.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.4
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• pp.54-63
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• 2013

In this paper, we evaluate the accuracy of the vertical positioning by distance using Network RTK-GPS. The experimental results confirm that Network RTK-GPS method can acquire data quickly and accurately than conventional leveling methods so that the Network RTK-GPS method is a relatively efficient and economical way for the vertical positioning. Results of validation using permanent GPS stations indicate that visible satellites, PDOP, and VDOP are very good for the vertical positioning. Integrated reference points such as U0997 and U0921 are satisfied with 3 ratings in the rules of public leveling and all the rest are proved improper. When the vertical positioning using Network RTK-GPS is implemented, the geoid height of EGM2008 should be applied for leveling. If the number of geodetic satellite are increasing in the near future, the vertical positioning using Network RTK-GPS can be possible in all the range.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.645-653
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• 2020

Recently studies on how to use the UAV (Unmanned Aerial Vehicle) are actively being conducted, and the National Geographic Information Institute published the 『Work Guidelines for Public Surveying of Unmanned Aerial Vehicles』. However, the guidelines do not provide the optimum shooting conditions required for each application. In this study, we tried to find the suitable shooting conditions for the production of 3D (Three-dimensional) spatial information and orthophoto. To this end, 45 experiments were conducted by various altitudes, overlaps, and camera angles within an above ground level of 150m. For evaluating the 3D modeling by shooting conditions, point densities of 9 verification areas were analyzed, and to evaluate the orthophotos, 1/1,000 digital maps were compared. Considering the quality of the output and the processing time for precise 3D construction, an altitude of 50m, an overlap of 70~80%, and a camera angle of 80~90° are suitable as shooting conditions, and an altitude of 100m and camera angle of 80~90° are suitable for orthophoto generation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.5
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• pp.407-414
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• 2007

Even Korea is big country of automobile, the occurrence of traffic accident is in last place in 29 OECD countries. If it is evaluated by assessment guide of investment over the development project of public-traffic facilities, it was shown that the direct economical loss was fairly great. In this study, in order to minimize the traffic accidents occurring at curve area of road, it was tried to establish the standard of non-passing distance. The close-range photogrammetry was used and three dimensional modeling was fulfilled. Currently, this paper was focused on presenting the standard of road design with analyzing the internal and external standard of non-passing distance.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.1
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• pp.29-42
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• 2019

In order to expand the qualitative aspects of public facility, this study used SNS data to derive user-oriented preference factors for public facilities and then were quantified in terms of supply side and demand side. To derive preference factor, LDA, one of topic modeling, was used and attraction index was calculated for each facility. In addition we analyzed spatial accessibility to measure the degree of service experience of users by using 2SFCA model. The study area covered public libraries of Seoul, Korea. As a result of study, five topics were extracted as preference factors for the public library: Circumstance, Scale of facility, Cultural program, Parenting, Books and materials. In particular topic of circumstance and parenting were newly derived preference factors unknown in previous studies. As a result of calculating attraction index for each library, the index of Songpa Library, Jungdok Library, and Namsan Library was high. Songpa library has received good evaluation in parenting factor, and Jungdok & Namsan library in circumstance factor. The accessibility of each region seems to better in center of Seoul where public libraries are crowded, but shrinking toward the outskirts. We expect that the proposed method will contribute to user-oriented public facility evaluation and policy decision making.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.4
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• pp.55-63
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• 2013

Network-RTK GPS positioning technique based on national CORS(Continuous Operating Reference Station) and wireless internet access as like VRS and FKP was developed to overcome the limitations of traditional RTK technique. In Korea, NGII(National Geographic Information Institute) provides network-RTK service based on 51 CORS and mobile internet network. The purpose of this study is the accuracy evaluation of the height determined by GPS VRS technique based on network-RTK, So, in this study GPS VRS positioning was accomplished through 1st level BM line located at Sancheong~Jinju and $2^{nd}$ level BM line located at Geochang~Sancheong and the average error of the each BM line was calculated as 2.15cm and 1.80cm respectively. This result shows that GPS VRS height positioning can be used in $3^{rd}$ and 4th public BM leveling and also work regulation is needed to apply the GPS VRS height positioning.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2006.05a
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• pp.152-157
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• 2006

Satellite imagery is generally used for investigating the damage from natural disaster for wide area and remotely piloted vehicle or aerial photos are used for the local damage. But for more detailed information such as damages of public facilities, these methods are inadequate and so in this case field surveying has been carried out. We tried to estimate the damage of public facilities faster and more accurately using photogrammetric method. We developed a digital stereo camera system by fixing two digital cameras on a frame, and with this system the photos of actually damaged areas were collected. The damages were estimated from these stereo photos. Then the estimated data was compared with field surveying data in order to verify our system.

• Spatial Information Research
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• v.18 no.4
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• pp.23-32
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• 2010

Water mains underground facilities are essential components to make up urban infrastructure. In order to manage these water mains underground facilities systematically and scientifically, GIS (Geographic Information System) had been constructed. For the sake of construction of GIS for water mains underground facilities, an exact underground detection and the construction of DB (Data Base) for buried water mains underground facilities should be preceded. In this study, in order to find out the ways to improve exact detection rate of data, the statistical analysis for the causes of detection raw degradation was done, and standardization methods of detection through a case study were suggested, When water mains underground facilities were measured, the detection of non-metallic water pipes was not carried out. The reason was that the results of detection was uncertain and detection was difficult because the assessment of public measurements was vulnerable. Moreover, due to the absence of standardized operating regulations for detection, systematic surveys weren't conducted. In this study, methods to standardize works over the detection of water mains underground facilities were presented so that we can improve the detection rate when we are doing that. As the proposals to improve detection rate, effective performance assessment over non-metallic pipes were presented, and related issues to supplement work regulations of public survey were described systematically.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.2
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• pp.121-134
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• 2013

The transverse cylindrical projection has been used in Korea since 1910s when the nationwide geodetic network was firstly established. However, the projection has a number of different types of functions according to a way of its mathematical derivation as well as a section of its coefficients and terms, for instance Gauss- Schreiber(GS) and Gauss-Kruger(GK) types. Although the transverse cylindrical projection itself is assigned to a system, projected coordinates would be diverse with respect to the function used in the actual calculation. In order to investigate impact of functions used in the computation, five different equations (i.e., 2 GS and 3 GK) were implemented in this study by using MATLAB. A series of numerical simulation tests has been carried out to compare and characterize them in terms of projection accuracy, difference of projected coordinates and distortion. Furthermore, a comparison between GS and GK function was made under the Korean gridding system, consisting of four zones. Results from the numerical computations were qualitatively analyzed and summarized in this paper.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.15 no.1
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• pp.117-129
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• 1997

In recent years, the 1 : 5,000 scale Digital National Basemap(DNB) has been generated under National Geo-graphic Information System(NGIS) Project. The DNB database generated will be the backdrop data for thematic maps, underground facilities maps and so on. The DNB database will be distributed to the government and private sectors in near future so that it should meet the requirements as the basic data. In order to assure the quality of DNB database, the establishment of quality assurance process to database was in great need. In this study, we were mainly concerned with improving the quality of digital national basemap database in geomatric aspect as well as the processing time due to the amount of digital data generated. As a results of this study, the quality assuance process of DNB database is established and automatic quality assurance program is developed. Also, the program developed in this study is contributed to quality assurance of DNB database as well as economic aspects.